Growth of Razorback Sucker (Xyrauchen texanus) at Bubbling Ponds

Fish Hatchery

November 2011

Lower Colorado River Multi-Species Conservation Program Steering Committee Members

Federal Participant Group California Participant Group

Bureau of Reclamation California Department of Fish and Game

US Fish and Wildlife Service City of Needles

National Park Service Coachella Valley Water District

Bureau of Land Management Colorado River Board of California

Bureau of Indian Affairs Bard Water District

Western Area Power Administration Imperial Irrigation District

Los Angeles Department of Water and Power

Palo Verde Irrigation District

Arizona Participant Group San Diego County Water Authority

Southern California Edison Company

Arizona Department of Water Resources Southern California Public Power Authority

Arizona Electric Power Cooperative Inc The Metropolitan Water District of Southern

Arizona Game and Fish Department California

Arizona Power Authority

Central Arizona Water Conservation District

Cibola Valley Irrigation and Drainage District Nevada Participant Group City of Bullhead City

City of Lake Havasu City Colorado River Commission of Nevada

City of Mesa Nevada Department of Wildlife

City of Somerton Southern Nevada Water Authority

City of Yuma Colorado River Commission Power Users

Electrical District No 3 Pinal County Arizona Basic Water Company

Golden Shores Water Conservation District

Mohave County Water Authority

Mohave Valley Irrigation and Drainage District Native American Participant Group Mohave Water Conservation District

North Gila Valley Irrigation and Drainage District Hualapai Tribe

Town of Fredonia Colorado River Indian Tribes

Town of Thatcher Chemehuevi Indian Tribe

Town of Wickenburg

Salt River Project Agricultural Improvement and Power District

Unit ldquoBrdquo Irrigation and Drainage District Conservation Participant Group Wellton-Mohawk Irrigation and Drainage District

Yuma County Water Usersrsquo Association Ducks Unlimited

Yuma Irrigation District Lower Colorado River RCampD Area Inc

Yuma Mesa Irrigation and Drainage District The Nature Conservancy

Other Interested Parties Participant Group

QuadState County Government Coalition

Desert Wildlife Unlimited

Lower Colorado River Multi-Species Conservation Program

Growth of Razorback Sucker (Xyrauchen texanus) at Bubbling Ponds Fish Hatchery

Prepared by

Matthew W OrsquoNeill David L Ward and William T Stewart Arizona Game and Fish Department Research Branch1

1 5000 West Carefree Highway Phoenix AZ 85086

Lower Colorado River Multi-Species Conservation Program Bureau of Reclamation Lower Colorado Region Boulder City Nevada httpwwwlcrmscpgov

November 2011

Lower Colorado River Multi-Species Conservation Program Steering Committee Members

Federal Participant Group California Participant Group

Bureau of Reclamation California Department of Fish and Game

US Fish and Wildlife Service City of Needles

National Park Service Coachella Valley Water District

Bureau of Land Management Colorado River Board of California

Bureau of Indian Affairs Bard Water District

Western Area Power Administration Imperial Irrigation District

Los Angeles Department of Water and Power

Palo Verde Irrigation District

Arizona Participant Group San Diego County Water Authority

Southern California Edison Company

Arizona Department of Water Resources Southern California Public Power Authority

Arizona Electric Power Cooperative Inc The Metropolitan Water District of Southern

Arizona Game and Fish Department California

Arizona Power Authority

Central Arizona Water Conservation District

Cibola Valley Irrigation and Drainage District Nevada Participant Group City of Bullhead City

City of Lake Havasu City Colorado River Commission of Nevada

City of Mesa Nevada Department of Wildlife

City of Somerton Southern Nevada Water Authority

City of Yuma Colorado River Commission Power Users

Electrical District No 3 Pinal County Arizona Basic Water Company

Golden Shores Water Conservation District

Mohave County Water Authority

Mohave Valley Irrigation and Drainage District Native American Participant Group Mohave Water Conservation District

North Gila Valley Irrigation and Drainage District Hualapai Tribe

Town of Fredonia Colorado River Indian Tribes

Town of Thatcher Chemehuevi Indian Tribe

Town of Wickenburg

Salt River Project Agricultural Improvement and Power District

Unit ldquoBrdquo Irrigation and Drainage District Conservation Participant Group Wellton-Mohawk Irrigation and Drainage District

Yuma County Water Usersrsquo Association Ducks Unlimited

Yuma Irrigation District Lower Colorado River RCampD Area Inc

Yuma Mesa Irrigation and Drainage District The Nature Conservancy

Other Interested Parties Participant Group

QuadState County Government Coalition

Desert Wildlife Unlimited

Lower Colorado River Multi-Species Conservation Program

Growth of Razorback Sucker (Xyrauchen texanus) at Bubbling Ponds Fish Hatchery

Prepared by

Matthew W OrsquoNeill David L Ward and William T Stewart Arizona Game and Fish Department Research Branch1

1 5000 West Carefree Highway Phoenix AZ 85086

Lower Colorado River Multi-Species Conservation Program Bureau of Reclamation Lower Colorado Region Boulder City Nevada httpwwwlcrmscpgov

November 2011

Lower Colorado River Multi-Species Conservation Program

Growth of Razorback Sucker (Xyrauchen texanus) at Bubbling Ponds Fish Hatchery

Prepared by

Matthew W OrsquoNeill David L Ward and William T Stewart Arizona Game and Fish Department Research Branch1

1 5000 West Carefree Highway Phoenix AZ 85086

Lower Colorado River Multi-Species Conservation Program Bureau of Reclamation Lower Colorado Region Boulder City Nevada httpwwwlcrmscpgov

November 2011

Table of ContentsEXECUTIVE13 SUMMARY5

Literature review5Growth during disease treatments 5Pond growth13 studies6

s

I L

IS

Conclusion 6

ITECETIROANTSUUMREMARY

NTRODUC

REVIEW

88

SUMBuMbARYblin

T

g

IONOFPFoAC

ndILsITSItEaSte fish H

atchery

13

9

Dexter National Fish Hatchery

10

14Grand Valley Native Fish Facility 15Ouray National Fish Hatchery 16

OVER

Wi

VI

llo

EW

w B

OF

ea

D

c

IF

h

F

N

E

a

R

t

E

i

N

o t

GC

n

E

a

S

l

IN

Fish Ha chery 17

EN

Uv

ER

a

A

ld

L

e

INF

Na

ORM

tion

AT

al

ION13

Fish

ON

Ha

FAC

tcChULerTyURE

METHA

ODS

SVariable growth

TORS THAT FFECTFISH ROWTH

18

PEG

17

Te

CI

m

FIC13

22

23pe

INF

ra

ORM

ture

A

TION ON RAZORBACK13 SUCKER13 GROWTH

23

24Density24

MCEA

Fe

S

ed13 Ha

URI

r

N

at

G13

indling

G

ons

RO

treWssTH13 IN13 CAPTIV

E FISH

ONCLUS

2526

25

II

SIONS

T

PE

HE

CIF

E

I

F

C13

I

F

R

E

ES

C

EA

SECTION UMTARY

NTRODUCS MTION

O

RC

F

H

D

R

I

EC

SE

O

A

M

SE

MEN

TR

DA

E

TI

A

O

T

N

M

S

E

NTS13 O

N RAZO

RB

ACK13 SUCKE

R13 GRO

WTH

27

28

2929

MRETHODSESULTS

3030

ADISCUSSION

32

III R

CK

A

N

Z

O

O

W

R

LE

BA

DG

C

E

K

M

G

EN

R

TS

3433

ISECTION SUMMARYNTRaRODUCzorb

TaIcONk grow

OWTH13 RAT

ESAT BUBBLI

NGPONDS ndash 2009

th rate in lined ponds

-shy‐2011

Growth rate in an unlined pond

3535

37

37

38

METH

Effe

O

c

D

t

S

o

f sorting on gro

wth 39Effect of Ich on razorback sucker growth rates39

Razorback growth rate in lined pondsGrowth rate in an unlined pond

39

39

41

RES

Ef

U

f

L

e

TS

ct

of sorting pract

ices on growth rates41Effect of Ich on razorback sucker grow

th rates

4341

313

13

Growth in Lined Ponds 43Growth in unlined ponds 43

CONC

Eff

L

e

US

cts

A

EffectIONS

of sorting on growth 44

LITER

CKN

A

OW

of

D

I

G

ch

TU

LE

RE13 C

E

I

M

o

E

n

N

r

T

a

S

z

orbacksucker growth rates

TED

51

504747

AP

AAPPPEEN

NDDICIXE12

SSFURVEY Q

-shy‐UESSTIONS

APPENDIX

3 TOLLOW UP URVE

YS

5858

PPENDIX ABULATED13 SURVEY RESULTS

6162

Li

Ta

st

Tableble13 1

of T

List

ab

of

les13

2 Facilitiesloca

and

tion

F

s13

i

availablet

gu

hat

res

athamajorve13 been

razorbackused13 to13 grow-shy‐out razorback suckers11

TaTabblle13 3e13 4

WStockater13 qua

ing13 densitlity13 ra

ies13 fornges13 a

ltarvaeach13 cul

e13 and13 fryture13 fa

sucker fish hatcheries12

Table13 5 Rearing13 densities13 at intincil

ensive13 culture13 fapondsity

cilities19

13

19

TaTab

blle13 6e13 7

ReaTypes

ring13 praof feed

ctices13 tused

haattraare13 unique

Table 8 Factors limiting productionzorback suck

to13 specificer13 hatcheries

rearing13 facilities

2020

Table 9 Reported and calculated growthat major

ratesrazorbackfrom13 the literature

sucker facilities

2021

FigureFigure13

12 PhotoRelationship between length and number of fish per pound18

FigFiguure13 re13 34EPhotffect

o13 ofof disease treatment experimental setup31

Figure13 5 Temperatureofdiselined13

ase treatments on razorback

ofanpondd13 unl

8inuppered13 pon

inds200

growth

9

rates

3338

FigFiguure13 re13 6713 13 RazTemperature

orof ponds 7 and 8 upper in 2009-shy‐201042

40

FigFiguure13 re13 9813 Raz13 Razor

or

back13 grback13 gr

owth13 rowth13 in

atesan unlined

in lined13 pondspond

4544

FigFiguure13 re13 101113 13 EffectEffect13 of

back13 grsor

owting13 onth in13 li

razneordback13 grvs13 unli

of Ich on razorbowthned ponds

45

ack growth13 rates4646

4

13

Executive13 SummaryThe few remaining razorback sucker populations are sustained by captive13 rearing13

and stocking programs and the survival13 of stocked suckers in13 the wild is largely13 associated

with size at stocking Experimental studies at Bubbling Ponds Fish Hatchery AZ have been

ongoing for the13 last 5 years13 to13 understand13 factors13 that affect razorback sucker13 growth13 in

captivity13 and to13 identify ways to improve growth rates and maximize size at release This

work13 consists of a literature review an experimental study of disease treatment effects13

and observations of individual13 fish growth in13 ponds under different13 conditions

Literature13 review

A literature review and hatchery13 site visits concluded that13 razorback13 sucker growth

is extremely variable and impacted by many factors including fish size and age sex density

amount of living space quality and quantity of food genetics and temperature13 Culture13

practices for razorback13 suckers vary13 widely13 and include13 differences in rearing13

environments rearing densities feeding regimes and types of feed as well as grading or

sorting practices Calculated growth rates from13 the literature vary widely and range from13

02 ndash 18 mmday with the highest growth rates reported from13 natural or semi-shy‐natural13

pond environments These growth rates indicate that juvenile razorback suckers have a

very hig growth13 potential under ideal rearing conditions13

Growth during disease13 treatments

Formalin copper sulfate potassium13 permanganate and salt are all chemicals

commonly used to treat Ichthyophthirius multifiliis and other disease outbreaks13 in hatchery13

populations of razorback13 sucker13 We exposed juvenile razorback13 suckers to 513 5-shy‐day13

treatments with each chemical to evaluate the effects these chemicals may have on growth

Fish grew an average of 235 mm TL during the 3 month study period No significant

differences in growth were observed among fish treated with any of the chemicals

compared to untreated fish (pgt005) Reductions in growth as a result of repeated chemical

treatments are not likely the cause of differences in growth rates among facilities that raise

razorback suckers Repeated chemical treatments may have other impacts to overall

fitness13 or long-shy‐term13 survival but these effects were not evident in our study

5

13

Pond growth studies

Growth13 studies13 were13 conducted13 at the13 Bubbling Ponds Fish Hatchery from13 2009 to

2011 These studies13 were13 largely13 observational13 because hatchery production requirements

prevented experimental manipulation of dependent variables Our initial13 work13 identified

razorback growth rates in lined ponds at standard fish density as 026 to 028mmday

(789 to 843 mmmonth) Additional13 studies include observations of growth rates in13 lined

and unlined ponds13 fish at different13 densities13 sorting13 practices13 and growth in13 the absence

of the13 ectoparasite13 Ich

Our data13 suggests that13 growth rates at the Bubbling13 Ponds Fish Hatchery are likely

as high as possible given the pond densities required to meet production goals and the Ich-shy‐

infested water that feeds the facility Sorting practices are successful in helping as many

fish as13 possible13 reach13 stocking13 length13 as13 fast as13 possible13 Unlined13 ponds may be able to

grow13 large13 fish at low densities but whatever factors13 allow for that growth13 are13 not able to

overcome high fish density Growth rates were highest following removal of Ich from13 the

Bubbling13 Ponds Spring13 032 mmday (96 mmmonth) but that growth13 rate13 decreased13

again13 as Ich re-shy‐infested13 the13 hatchery

Conclusions

We conclude that under typical hatchery operations (maximizing number of fish

produced)13 the growth13 rate13 of razorback13 suckers is relatively13 consistent at Bubbling13 Ponds

hatchery13 at13 02-shy‐03 mmday (6-shy‐9 mmmonth)13 but is lower than growth13 rates13 at other

facilities (02 ndash 18 mmday Ward et al 2007)13 This growth13 rate13 has13 been13 constant in both13

lined and unlined ponds at all fish densities we were able to measure is temperature

independent13 and13 is likely13 enhanced13 by13 separating13 fast and13 slow-shy‐growing13 fish after the first13

year of growth13 To achieve13 growth13 rates13 substantially13 higher than13 this13 will likely13 require

significant changes in rearing practices that may not be practical in order to13 reach13

numerical production13 goals

Two major changes that might result in higher growth rates are substantially

reducing fish density and modifying the way spring water is delivered to the facility (via

either repeated chemical treatments or enclosed concrete water diversions) to eliminate

Ich from13 the hatchery source water Other potential changes not address by our work

6

13

include13 flow-shy‐training razorbacks much previous literature including MSCP-shy‐funded13 work

on razorback suckers13 suggests13 that fish growing13 in flowing13 water13 will grow faster13 than13 fish

in still water (Jorgensen and Jobling 1994) Furthermore there are a wide variety13 of

potential benefits associated with growing13 fish13 in flowing13 water in addition13 to increased

growth13 rates13 (Davidson13 1997 Castro13 et al 2011)13 Finally given that stocking of smaller

razorbacks13 has13 been13 largely unsuccessful13 perhaps13 BPH goals could be changed from13

producing 12000 fish at 300+ mm per year to a smaller number of very large fish each

year Growing fewer larger fish could potentially be accomplished in the same time frame

as more smaller fish but a better understanding13 of how13 density alters growth rate would

be required to be confident13 of this

7

13

I Literature13 Review

Section13 SummaryThe few remaining razorback sucker populations are sustained by captive rearing and stockingprograms Captive-shy‐reared razorback suckers commonly13 experience13 high predation whenstocked into natural environments This13 creates13 the need to rear fish to larger sizes13 in captivityand to13 find new ways to13 improve growth for captive-shy‐reared fish We reviewed publishedliterature and agency reports for information on factors that affect growth of13 razorback suckerSite visits to13 razorback sucker production facilities and surveys of fish hatchery13 personnel wereconducted to obtain information on current rearing practices Razorback sucker growth is13 extremely13 variable13 and impacted by13 many13 factors including13 fish size13 and age sex densityamount of living13 space quality13 and quantity13 of food genetics and temperature This makesevaluations of individual factors that affect growth difficult Culture13 practices for razorbacksuckers13 vary widely and include differences13 in rearing environments rearing densities feedingregimes and types of feed as well as grading or13 sorting practices The focus at most razorbackrearing facilities is production so the types of data that are collected13 are often insufficient fordetailed13 evaluations of rearing practices on growth Calculated13 growth13 rates from theliterature vary widely and range from 02 ndash 1813 mmday Typically the highest growth13 rates arereported from natural or semi-shy‐natural pond environments These growth rates indicate thatjuvenile razorback suckers have a very high growth potential under ideal rearing conditionsDetailed replicated studies are needed to accurately compare the effects of individual rearingpractices on13 growth These types of studies will ultimately provide both time and cost-shy‐savings13 to production facilities by reducing the time it13 takes for razorback suckers to reach stockingsize improving overall production efficiency

8

13

Introduction

State and federal wildlife management agencies have been rearing razorback

suckers in captivity since the 1970rsquos (Toney 1974 Hamman 1985) to augment declining

natural13 populations Both wild-shy‐caught larvae13 and captive-shy‐bred fish are reared at fish

hatcheries13 and13 grow-shy‐out ponds throughout the13 southwestern13 United13 States13 (reviewed13 in

Mueller 2006) Each facility has unique environmental conditions and different rearing

methods which yield different growth rates Unlike commercial fish species which have

been cultured and studied extensively little published information is available on the

effects of various rearing methods on growth of razorback sucker

Low survival rates13 of stocked13 razorback suckers13 (Brooks13 1986 Marsh13 and13 Brooks13

1989 Marsh13 and13 Pacey13 2005)13 have13 caused13 target sizes for stocking13 to13 steadily13 increase13 in

efforts to reduce predation mortality (Marsh et al 2005 Schooley and Marsh 2007)

Rearing fish to larger sizes comes with increased costs and creates the need to know which

factors13 have the greatest impact on growth rate and how these factors can be controlled to

maximize growth This document compiles and summarizes information on current

captive13 rearing practices13 and associated13 growth13 rates13 for razorback sucker13

We reviewed relevant13 published literature and agency reports on13 razorback13 sucker

to compile background information regarding the effects of environmental factors and

rearing methods on growth A questionnaire was developed (Appendix 1) and sent to

hatchery managers who rear razorback suckers Follow up surveys13 were13 also13 conducted13

by telephone (Appendix 2) Information on rearing densities water quality diseases and

management practices at each facility were recorded Site visits to Bubbling Ponds State

Fish Hatchery13 in Arizona Dexter National Fish Hatchery in New Mexico Grand Valley

Endangered Fish13 Facility13 in Colorado13 Ouray13 National13 Fish13 Hatchery13 in Utah and the Willow

Beach National Fish Hatchery in Arizona were also conducted as part of this knowledge

assessment Telephone interviews were conducted with personnel from13 other locations

that13 produce razorback13 suckers (Uvalde National13 Fish Hatchery13 Hualapai Ponds13 Lake

Mead Fish Hatchery and JW Mumma Fish Hatchery) or facilities that formerly produced

razorback suckers but currently focus on other species (Wahweap Fish Hatchery Achii

Hanyo13 National Fish Hatchery Mora National Fish Hatchery)

9

13

Information from13 all of these sources is summarized to aid future researchers in the

design of more detailed studies on razorback sucker13 growth Understanding the13 factors13

that13 control13 razorback13 sucker growth will13 allow13 expanded fish-shy‐rearing capabilities13 and13 aid13

in reaching management objectives for stocked fish Preservation of genetic resources for

razorback suckers13 depends on captive rearing and stocking programs until permanent

solutions to factors that prevent wild recruitment can be found

Summary13 of Facilities

There are13 over 50 locations13 that have13 been13 used to13 rear13 razorback suckers13 (Table13 1) These

include13 both13 intensive13 culture13 facilities13 with13 raceways13 or circular13 tanks13 as13 well as13

production13 ponds13 golf-shy‐course13 ponds and natural floodplain-shy‐wetlands The majority of

razorback suckers that are stocked come from13 six major production facilities Bubbling

Ponds State13 Fish13 Hatchery13 The Grand13 Valley13 Endangered13 Fish Facility13 and13 Dexter13 Ouray13

Willow13 Beach13 and Uvalde National13 Fish Hatcheries13 Tables 2-shy‐313 outline13 the13 types13 of fish

holding facilities and water quality conditions that exist at each of these main production

locations A brief summary of procedures for rearing razorback suckers at each of these

facilities13 follows

These summaries are based on interviews conducted with hatchery personnel in July 2007 during site visits

This information13 is provided only to give a brief overview of razorback grow-shy‐out procedures Please verify13

accuracy13 of specific information with individual hatchery managers

10

13

Table13 1 List of locations13 that have13 been13 used to13 grow-shy‐out razorback suckers

$$amp ()amp$+ ($ampamp$+( $amp()$+ $amp()amp+(-0(12(342056( )0(-75amp8(95amp( 0$$05(lt==gt( 5amp+(amp4amp(Aamp+amp050+(12(14$6( 5amp+(amp4amp8(B$5+( B7$(lt==lt8()C0C05(lt===8(D0$05(0($(lt==E8(amp2F(0($(lt==E(

GltHI5+(342056J( K0L05(Damp$(12(342056( K0L058(D0M(0L4( N$055(lt==E( FF(-0(12(342056( D05(9$F8(B$5+( -42amp5(amp+($amp(lt==lt( OP0(0+(342056( $+05(B68(D0Q+( N-R(lt==gt( S56(Damp$(12(342056( D05(T05amp$8(N2( B7$(lt==lt8(U5Qamp(0($(lt==H8()C0C05(0($(lt==E8(0$$05(lt==gt8(N-1V-(WXXX( NQ$+0(Damp$(12(342056( NQ$+08(Y0L( N-R(lt==gt( V2M07(12(342056( M058(N2( B7$(lt==lt8(Qamp(amp+(5+M42(lt===( V$$M(042(Damp$(12(342056( 0$M(3Q05(KF(amp(B$5+(RQ058(95amp( 3ampamp(WXXgt( 942(3amp6( D05()5P058(95amp( N-1V-(lt==Z( --+-0+-12-3(4-5 )005(7amp+( 5amp+(amp4amp8(B$5+( Y2+(amp2F8(705amp$(4FFamp4amp( ltgt(5+(7amp+( 5amp+(amp4amp8(B$5+( )C0C05(0($[(WXXX( amp+(7amp+(( 5amp+(amp4amp8(B$5+( )C0C05(0($[(WXXX( B$6F05()amp+( BampC$0amp40(C(B$5+(amp+(ampampamp( )C0C05(0($[(WXXX8(B7$(lt==lt( B$5+(I(W](++amp$($00+(7amp+( 5amp+(T$$068(B$5+( )C0C05(lt===( KP0(5+(7amp+( 5amp+(T$$068(B$5+( )C0C05(0($[(WXXX( 32$amp0(7amp+( 5amp+(T$$068(B$5+( )C0C05(0($[(WXXX( 35020C(505amp(7amp+( 5amp+(amp4amp8(B$5+( )C0C05(lt===8(B7$(lt==lt( 0-6-3+ $620(Famp47$($C(450( $6208(B$C5amp( ^50amp($C(450_(9-N(R00542()5P( 08(95amp( 52(WXXH8(52(WX]( )0($C(450(7amp+( )08(95amp( 0$$05(amp+(V4P(WXX]( 768639 0amp(50(DVR( -2(C(Y4amp8(95amp( 52(WX]( B$(32(O0Q00()amp+( B$(Damp$(V$+$C0(R0C08(D05($6208(B$C5amp( 52(lt===8(amp4P$06(amp+(O55(WXXX8(0$$05(lt==gt( SQ05amp(M$+$C0(amp0F0amp(50( D05(OP0(0+(ampC$M8(D0Q+( N-R(lt==gt( -0amp5(V2( D52(C(`F8(95amp( ^5042Fampamp(amp+(O0$0(lt==gt8(amp4P$06(amp+(O55(WXXX( )1(+ KQ(4Q0( OP0(2Q08(95amp( 0$$05(WXXlt8(0$$05(amp+(5P0(lt==Z( 95amp(aQ0amp$0( OP0(2Q08(95amp( -$56(WXX]( -2(-+0Mamp+05( OP0(2Q08(95amp( -$56(WXX]( `F(BQ0( OP0(2Q08(95amp( 0$$05(WXXlt8(0$$05(amp+(5P0(lt==Z( Kamp+6( OP0(2Q08(D0Q+( -$56(WXX]( D52(B20F020Q0( OP0(2Q08(D0Q+( -$56(WXX]( D52(X($0( OP0(2Q08(D0Q+( Y6(V$05(N-R8(705amp$(4FFamp4amp( V$$M( OP0(2Q08(D0Q+( Y6(V$05(N-R8(705amp$(4FFamp4amp( D0Q+(A( OP0(2Q08(D0Q+( Y6(V$05(N-R8(705amp$(4FFamp4amp( D0Q+(O5Q0( OP0(2Q08(D0Q+( Y6(V$05(N-R8(705amp$(4FFamp4amp( 0+58lt+--457(5 9Q0(50ampampamp( D05(T05amp$8(N2( )C0C05(0($[(lt==E( ampamp(5+0( D05(T05amp$8(N2( )C0C05(0($[(lt==E( 2ampamp(F( D05(T05amp$8(N2( ++0(amp+(3amp0(lt==Z( O0(W=( D05(T05amp$8(N2( N-1V-(WXXX( O0(F( D05(T05amp$8(N2( ++0(amp+(3amp0(lt==Z( S$+(425$06(V2( D05(T05amp$8(N2( ++0(amp+(3amp0(lt==Z8(++0(WXXgt( O00+(7amp+(amp(20(Namp2(amp( D05(T05amp$8(N2( U5Qamp(0($(lt==H8()C0C05(0($(lt==E( =($+ 1$6+(OF(0(75P(GY0$0(75ampJ( O(T08(D0Q+ (52(WXXH( Y5amp++(-0(amp5(B$$00( 9$F8(B$5+( -42amp5(amp+(Oamp(lt==lt( 5MI(7amp+( D05(15Fampamp8(D( -42amp5(amp+(Oamp(lt==lt(

11

13

Table 2 Facilities available at major razorback sucker fish hatcheries

$amp( )$+(-+( 0(1(2$amp3amp(( 4-56+ amp7(8-+1$(9+( lt3-5( 8=$33( 23gt(805(

$amp()amp+(-(012345( 0(0+amp(A(BBCC(05 ampD(ED F CGBH IACCCACCC BJH K$+L(0D

amp$+(M$gt$ O-$+(+($P

B N B

CGBH IACCCACCC BABHC FANCC

BJH

Qamp+-3$+($P F FHC 637134(801amp0$(-(012345( H(L$33gt($O-amp1+(gt33A(

BCCC(05 ampDRK$+L(0D amp$+(M$gt$ M$-3$+($P Qamp+-3$+($P Qamp+-3$+($P

9O-$+amp$

SF S BC SC HC TC

CGI((IGC( HAHCC HSC IBC BCC IC

9O-$+amp$ BC SC 940amp+(amp21amp(8013(-(-02$15( U-ampamp0$3(D+ampPamp(gt$+ Qamp+-3$+($P IS VCC IB

W+Lamp1(+$+amp(0D( E-50D(+ampX+(gt$+( Qamp+-3$+($P JT BCC H K$+L(ED T CGBH(Y(CGH(

lt405(801amp0$(-(012345( J(L$33gt(gt33A(FCC(05( ampD(0D BS CGIBH(Z(CGBH( IC Qamp+-3$+($P NC IBC H Qamp+-3$+($P BJ VCC IC((IH

=$$gt(302(801amp0$(-(012345( 3$+(L$D(Q3+$D( MampX+(gt$+( amp$+(M$gt$ N IAHCC

amp$+(M$gt$ IF IFACCC 9O-$+amp$ FC IC

0$+3(801amp0$(-(012345( B([0(9O-amp1+()33A( IHCC(05 ampD(0D II I

K$+L(0D amp$+(M$gt$ amp$+(M$gt$

NJ B IB

GBH(Y(IGC( FAHCC IACCC

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IB N

BCC NACCC

12

13

Table13 3 Water13 quality13 ranges13 at each13 culture facility$amp ($)$++) -+$

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Bubbling Ponds State13 fish Hatchery13

Bubbling Ponds Fish Hatchery in Arizona does not maintain razorback sucker

broodstock on site Razorback suckers are received either as juveniles from13 Willow Beach

National Fish Hatchery13 or as13 newly-shy‐hatched larvae from13 Dexter13 National Fish Hatchery

Larval fish are13 typically13 placed13 into13 an unfertilized unlined 0613 acre13 pond13 in the13 spring In

September the pond is harvested by draining the pond and seining All fish that have

reached the target size (300 mm TL) are stocked Fish that are too small to stock are split

up equally between the six remaining grow-shy‐out pond at an13 average13 density13 of about 5000

ndash 7000 fish per pond Fish are fed by hand at approximately 25 body weight split

between morning and evening feedings Fish are either fed a catfish diet made by Rangenreg

13

13

that is enriched with spirulina and krill or razorback sucker diet made by Silvercupreg

depending on availability Fish are monitored visually and by sampling using a cast net

When a large number13 of fish have13 grown to13 the13 target size they13 are13 harvested13 by13 draining

the pond and seining13 Fish are again13 sorted by hand and the largest13 fish are stocked13 Fish

that13 have not13 reached the target13 size are returned to the ponds for further grow-shy‐out13 On13

average it13 takes one to two years for fish to reach the target13 size with fish growing13 an

average of 06 mmday Target numbers for production are 12000 razorback suckers

annually (300 mm TL) The biggest difficulty in rearing razorback suckers at Bubbling

Ponds13 Fish Hatchery13 is protozoan13 parasite13 infestations13 (Ich) and13 associated13 bacterial

infections that come from13 an open spring source that is inhabited by mosquitofish

Dexter National Fish Hatchery13

Dexter National Fish Hatchery maintains four separate razorback sucker13

broodstocks13 These fish are spawned on13 site and larval13 fish are placed directly into 01 acre

ponds at a density13 of about 20000 larvae13 per pond (50 ndash 100 thousand13 per13 acre)13 Ponds

are fertilized with alfalfa13 pellets and superphosphate two weeks prior to receiving13 larvae to

produce13 natural13 feed for larval13 fish13 Ponds are13 fertilized again with alfalfa13 pellets one week

after larvae are introduced13 Fish are fed a catfish starter diet13 (sizes 1-shy‐3) made by Rangenreg

that13 is enhanced with spirulina13 and krill13 and then switched over to the razorback13 diet13 once

they are large enough to eat 1mm13 crumble Fish are fed twice a day by hand four days a

week13 at 25-shy‐60 body weight Feed ration is decreased if excess feed is seen remaining

on the13 pond bottom13 following feedings Fish are not graded or sorted during this grow-shy‐out

period Razorback suckers are harvested in the fall by draining ponds completely Fish are

sorted13 at harvest and13 distributed13 to13 other13 facilities13 for further13 grow-shy‐out depending on13

current size requirements Razorback suckers are on average 100 ndash 200 mm TL after the

first growing13 season13 and13 generally13 take13 1 -shy‐18 months for a majority of the fish to reach

300 mm TL There are 16 different species of fish maintained at Dexter National13 Fish13

Hatchery13 and13 having sufficient pond13 space13 to13 grow out separate13 groups13 of fish is the13

limiting factor for production of razorback suckers at this location

14

13

Grand Valley13 Native13 Fish Facility13

The Grand Valley Native Fish Facility maintains its own brood stock13 in13 eight13 ponds

located at the Horsethief Basin Wildlife Area in Grand Junction Colorado Fish are

spawned13 on site13 and13 larvae13 are13 reared13 indoors in fiberglass13 tanks13 at the13 24-shy‐Road13 Fish13

Hatchery13 in Grand13 Junction The 24-shy‐Road13 Hatchery13 consists of two13 separate13 recirculating13

systems that operate using de-shy‐chlorinated13 city13 water13 and two13 large13 fluidized-shy‐ bed sand

filters13 and13 rotating-shy‐drum13 filters for waste removal Fish are held in 4-shy‐foot (n=78) or 8-shy‐foot

(n=14) diameter fiberglass tanks Larval fish are started on prepared feeds immediately

after swim-shy‐up and fed exclusively razorback feeds made by Silvercupreg Fish are started on

a 0-shy‐250 micron razorback diet for the first 10-shy‐1213 days13 and13 then13 fed with13 gradually13

increasing13 feed sizes based13 on observations of feeding13 (250 ndash 400 micron 1 starter) Feed

sizes are mixed when transitioning to the next larger feed size These razorback diets are

specially sifted by Dr Rick Barrows (USDA13 Hagerman experiment station Idaho)

Razorbacks13 are13 typically eating 1mm13 extruded pellets by the time they are 35 to 4 inches

in length Fish are fed approximately 70 body weight per day initially and then gradually

reduced to 15 body weight by the time they reach the 300 mm TL target size Fish are

fed seven days13 a week using13 12-shy‐hr13 belt feeders It takes13 12-shy‐16 months to grow fish to the

target13 size in13 the hatchery13

Razorback suckers are sorted after three months and culled to about 4000 fish per

family lot Culled fish are stocked into leased grow-shy‐out ponds Stocking densities for

juveniles in these ponds is based on previous13 stocking and harvest13 rates13 and is pond

specific13 Grow-shy‐out ponds are13 harvested13 periodically13 using Fyke13 nets13 or trap13 nets13 and13 fish of

the target size are stocked Disease problems (Ich Lernea) water quality problems (low

DO) and difficulty in removing all of the fish are challenges for grow-shy‐out of razorback

suckers13 in these13 natural ponds13

Fish reared13 in the13 24-shy‐Road facility are sorted again at four to five months of age into

small and large size groups to obtain more uniform13 growth rates Batch estimates of fish

weight are done every month for each tank A group of fish are weighed and counted to

give an average weight for the tank with lengths estimated based on a lengthweight chart13

The biggest difficulties13 for growing13 out razorback suckers13 at the13 24-shy‐Road13 Fish13 Hatchery13 are13

insufficient space and water flow (oxygen) to grow fish to the target size At the Horsethief

15

13

Basin13 Ponds where broodstock13 are reared13 diseases such as Ich are problematic because

water is pumped directly from13 the Colorado River

Ouray13 National Fish Hatchery13

Ouray13 National13 Fish Hatchery maintains its own broodstock and13 spawns13 fish on-shy‐site13

Larvae are transferred from13 indoor hatching tanks to unfertilized 02 acre outdoor ponds

and stocked at densities 10000 ndash 20000 larvae13 per13 pond13 Even13 though13 outdoor13 ponds13 are13

covered with13 bird13 netting13 avian predators13 still get caught in the13 nets13 if they13 can see fish

Ponds are dyed blue13 as the13 fish grow to13 prevent avian predation13 While in the outdoor

ponds13 fish13 are13 fed a slow-shy‐sinking salmon diet made by Silvercupreg twice daily by hand

Amount of feed is based on periodic sample counts Fish are grown until late September at

which time temperatures require that all fish13 other13 than13 adult broodstock13 be13 brought

inside for the winter Ponds are drained completely and fish are sorted by hand Fish that

have reached the target size (300 mm TL) are stocked into the Green and Colorado Rivers

All remaining fish are moved indoors13 and13 held13 in three-shy‐foot (n= 30) or eight-shy‐foot (n=27)

diameter circular tanks On average it takes 12 ndash 18 months to grow fish to the 300 mm TL

at Ouray13 hatchery13

Razorback suckers are held during the winter in a recirculating system13 that

operates13 using13 two13 large13 fluidized-shy‐bed sand filters and a rotating-shy‐drum13 filter for solids

removal Fish are fed the Silvercupreg razorback diet using belt feeders There is currently

capacity13 to13 hold13 only13 20000 200-shy‐300 mm TL fish inside the facility and any extra fish13 are13

stocked13 into13 floodplain-shy‐wetlands or used for research purposes13 Ouray no longer leases

any private grow-shy‐out ponds Grow-shy‐out ponds were troublesome due to poor water quality

harvesting13 difficulties13 and13 non-shy‐native13 fish introductions13 The biggest difficulty13 for

production13 of razorback13 suckers at the Ouray13 National13 Fish13 Hatchery13 is space13 during13 the

winter to maintain large numbers of fish and high iron and manganese in the well water

that must be filtered out prior to use

16

13

Willow Beach National Fish Hatchery13

Willow13 Beach National13 Fish Hatchery receives wild-shy‐caught larvae from13 Lake

Mohave Larvae are treated for diseases with formalin and malachite green and placed in

45 ten-shy‐gallon13 flow-shy‐through aquaria13 Recirculated13 solar heated water13 22-shy‐25deg C is used to13

allow production of warm13 water fish at this traditionally cold water facility (Figiel 2003

Figiel et al 2005) Fish are fed brine shrimp nauplii to satiation every hour and after 14

days small amounts of specialized larval fish diet (Encapsulon13 Cyclopeeze13 spirulina13 and

artificial plankton) are introduced After 30-shy‐6013 days13 fish are13 transferred13 to13 six13 32-shy‐gallon13

fiberglass troughs at densities of 1000 to 1500 fish per tank and then a month later moved

outside13 to13 eight recirculating13 raceways that use a combination of well water and solar-shy‐

heated water to maintain temperatures of 22 ndash 25deg C during the summer months

When13 in13 the outside raceways13 fish are fed the razorback13 diet13 using13 belt13 feeders and

fed by13 hand13 at 10 -shy‐ 70 body13 weight per13 day Feed amount is adjusted based on sample

counts according to a feed conversion program13 developed for razorback suckers by Willow

Beach Hatchery personnel This program13 uses length and number-shy‐per-shy‐pound generated

from13 several years of razorback growth data (Figure13 1) Fish are13 sorted13 opportunistically13

and are not handled during the summer months when water temperatures are above 20degC

In 2004 the target size for stocking was 325 mm TL or greater (WBNFH 2004) with a

target13 of producing13 6000 fish per year Reaching this13 target size usually13 takes13 two13 growing13

seasons13 The biggest difficulty13 in rearing13 razorback suckers13 at Willow Beach13 National Fish

Hatchery13 is insufficient space13 to13 grow fish to13 increased13 target sizes (400-shy‐500 mm TL)

Uvalde13 National Fish Hatchery13

Uvalde13 National Fish Hatchery13 in Texas13 receives 35000 ndash 60000 razorback sucker13

fry annually in MarchApril from13 Dexter National Fish Hatchery The fry are acclimated in

bags submerged in the pond for a minimum13 of one hour and released into13 a 1 acre13 fertilized13

pond where they are reared for the remainder of the summer Fingerlings are fed a starter

razorback diet when they reach approximately 50 mm TL In AprilMay the previous year

class of razorbacks are captured from13 their over-shy‐wintering pond enumerated graded and

split into13 one-shy‐acre grow-shy‐out ponds Approximately 4000 ndash 5000 fish will be13 placed13 in each13

one acre pond for summer grow-shy‐out Fish are reared for approximately 150 days (May ndash

17

13

Oct) and fed the Bozeman razorback diet two times a day five days a week at 15 ndash 30

body weight per day based on average water temperature

Figure 1 Relationship between length and number of fish per pound

In general13 juvenile razorback13 suckers (received as fry13 during13 the previous spring)13

reach the target size of 300 mm TL in approximately 6 months In 20062007 Uvalde

produced 6000 razorback suckers 300 mm TL for introduction into the San Juan River

Starting13 in 2008 Uvalde NFH will be producing13 and distributing13 12000-shy‐ 300 mm TL

razorbacks for stocking into the San Juan River Predation from13 migrating cormorants has

occurred but timing of harvest and over wintering protection methods such as covering

ponds with netting or placing fish indoors helps to minimize losses during the cormorant

migration (November to March) Uvalde has experienced razorback mortalities because of

bacterial problems but these are usually resolved through the use of oxytetracyline

medicated feed

Overview13 of Differences in Culture Methods

Several differences were noted when conducting surveys at each of the five main

production facilities for razorback sucker (See Appendix 3) These differences include

different stocking13 and13 rearing13 densities13 (Table13 4-shy‐5) various feeding regimes and type of

18

13

lt=amp

feeds (Table 7) as well as differences in grading or sorting practices Some of these

differences are13 related13 to13 whether13 or not razorback suckers13 are13 being13 reared13 in extensive-shy‐

culture13 facilities13 (ponds) or intensive-shy‐culture13 settings13 (raceways13 o tanks)13 Some13 practices13

are unique to a single facility13 or a couple of facilities (Table 6)13 Managers at each facility13

were asked to identify the biggest13 difficulty or constraint13 that13 they experience when13

growing-shy‐out juvenile13 razorback suckers13 at their13 respective13 location13 Space constraints13

water quality and disease problems were the main factors limiting production of razorback

suckers13 at these13 facilities13 (Table13 8) Calculated or reported growth rates from13 the literature

vary widely (Table 9) and range from13 02 to 18 mmday These growth rates indicate that

juvenile razorback suckers have a very high growth potential under optimal rearing

conditions13

Table13 4 Stocking13 densities13 for larvae13 and13 fry in ponds

$amp( )(+amp-( 01-2(3(4amp56( 4amp56(+amp-( 01-2782-( $amp () + --amp +amp0amp)+amp 12-3amp ( )+amp0amp+amp --amp +amp0amp)+amp 42556789amp8 ( +amp0ampgt+amp 3amp +amp0amp+amp A-BC-Damp (E + 3amp )+ F-6ltamp ) G+ 3amp G+

Table13 5 Rearing13 densities13 at intensive13 culture13 facilities13

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6amp())amp++-$amp 610 77amp2amp1amp 0amp2amp1amp 053

19

13

Table13 6 Rearing13 practices13 that are13 unique to13 specific rearing13 facilities13 $$amp( )$+-(amp$-(0(1-amp2034( $amp()amp+( -0$(12(33+(amp(amp134$53+(amp$amp3+(6amp+(

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Table13 7 Types of feed used at razorback sucker13 hatcheries13 $amp ()amp+-amp0- $$)1amp23 45-amp)-$5)1amp23 $amp()amp+( -amp$amp+(amp+( -amp012$3+(amp+4(amp5215$(0+( 65ampamp7(85209(+2($1(87((15315lt=(+2(

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$1(87(15315lt=(+2(D5$$(3(lt5$$gt(02+(gt( 6lt=(511B(

L15gt( G1$5(lt1lt$51(25amp=(Aamp+( amp+(

HIJKH(Dlt1amp(15315lt=(+2(I(C2(CH(+5gt( )11$gt($511(02+(15315lt=(+2(

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M$$B(5lt9(-5$+( NO515(G1$5(219( L2+1(15ltB5gt(Aamp+(5amp+( amp$amp+(amp+(

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$1(87(15315lt=(+2($1(87(15315lt=(+2( $1(87(15315lt=(+2(

Table 8 Factors limiting production at major razorback sucker facilities

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20

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D(B(8

gtgt (

Table9Reportedandcalculatedgrowthratesfromtheliterature

Calculatedgrow

thratesbasedon

informationprovidedinliterature

aApproximationsofmaximum

grow

thpotential(basedon

average13 maximum

sizesiffishreportedatharvest

21

13

General Information on Factors that Affect Fish Growth

Growth in fish is extremely variable and is impacted by many different

physiological and environmental factors Growth rates are known to change with size and

age sex season activity level density amount13 of living space quality and quantity of food

genetics and temperature (Brett 1979) Growth experiments conducted at different times

of year can result in growth rates that are not comparable As fish become larger their

physiological13 potential to grow decreases making determination of growth rate dependent

on the size of the starting fish and the length of the experiment (Busacker et al 1990)

Genetic factors also have great potential to influence growth rate Some species have

strains13 and13 races13 that display vastly different growth potentials (Reinitz et al 1979) All of

these factors combine to make assessment of the individual factors controlling fish growth

difficult13

Water temperature is probably the most important variable affecting growth rate13

All of the basic functions that affect growth such as feeding digestion and metabolism are

temperature-shy‐dependent13 Growth13 is inseparably13 tied13 to13 bioenergetics13 and13 therefore13 also13

tightly tied to temperature When temperatures are below optimum daily temperature

fluctuations can stimulate growth Photoperiod is also commonly linked to water

temperature and can influence growth rates in fish (reviewed in Brett 1979)

Fish density13 is known to13 affect growth13 and13 can alter13 growth13 rates13 in several ways13

Fish that exhibit strong territorial behaviors13 or natural schooling tendencies13 will

experience reduced growth if densities are too high or too low (Brett 1979) Dominance

hierarchies where some fish feed more aggressively than others can also lead to high

variability13 in growth13 rates13 (Koebele13 1985) Crowded13 conditions13 also13 cause physical

interference13 between13 fish and13 poor water13 quality13 which13 reduces13 growth13 (Busacker13 et al13

1990) The effects of fish numbers space and feeding opportunity are frequently correlated13

and often13 difficult13 to distinguish (Brett13 1979)13

It is impossible to study the effects of environmental factors on growth without also

evaluating feed rations (Brett 1979) Amount of food quality of the diet particle size

number of feedings per day and time of feeding have all been shown to affect growth

(Busacker et al 1990) In controlled laboratory studies food is usually fed ad libitum13

22

13

(constantly available) and other variables are altered to assess impacts of environmental

factors13 on growth13 These studies13 are13 usually13 conducted13 in tanks13 or raceways13 because13

researchers must verify that food is constantly available to the fish which is difficult to do

in large pond environments where the fish and the bottom13 are often not visible (Busacker13

et al13 1990)

Specific Information13 o Razorback13 Sucker13 Growth

Variable13 growth

Growth in razorback suckers is naturally highly variable and may be a function of

their evolutionary history (USFWS13 2002)13 Minckley (1983) speculated that13 wide size

variation in a single cohort of razorback suckers may be adaptive with fast-shy‐growing13 fish

that13 reproduce at a young13 age surviving13 better in13 high discharge years and slow-shy‐growing13

smaller fish surviving better during drought periods This highly variable growth rate

makes rearing razorback suckers in a production setting difficult because fish from13 a single

cohort do not reach the target stocking size simultaneously One of the major tasks for

aquaculture is to maximize both individual growth and total production13 (Gerking13 1978)13

This becomes more difficult when the species being cultured exhibits highly variable

growth13 rates13 because of genetic influences as is the case with razorback13 suckers13

Razorback13 sucker growth13 is typically very13 rapid13 during13 the first13 year of life13 and then13

declines with age First year growth can be as low as 50 mm and as high as 350 mm (Valdez

et al13 1982 Minckley13 1983 Mueller13 1995) Razorback sucker13 grow rapidly13 for

approximately the first five or six years of life and then growth slows13 (McCarthy13 and13

Minckely 198713 Tyus 199813 Minckley et13 al 1991)13 Growth of older individuals in13 extant13 wild

populations is very13 low (Minckley 198313 Tyus 198813 Modde13 et al 1996)13 Wild growth13 rates

for mature adult fish in Lake Mohave based on PIT tag recaptures were often too small to

be accurately measured for both males and females over the time period of 1987-shy‐199713

(Marsh and Pacey 1998) This information suggest it will take substantially longer to rear

fish to13 increasingly13 larger13 stocking13 sizes (40013 ndash 500 mm TL) than it did to reach the target

size of 300 mm TL

Growth in ponds

23

13

One of the main strategies for maintaining genetic refugia and self-shy‐sustaining13

populations of razorback13 sucker in the lower Colorado13 River basin13 is to rear razorback13

sucker13 larvae13 in production13 ponds until they13 are13 a suitable13 size for stocking13 (USFWS13 2004)

Pond culture has proven useful to promote rapid growth of juvenile razorback suckers

(Kaeding and Osmundson 1989) Marsh (1994) reported that growth rates of razorback

suckers13 reared13 in golf-shy‐course13 ponds exceeded13 the13 best growth13 rates13 obtained13 under

intensive13 culture13 conditions13 at federal hatcheries13 especially13 during the13 first several years13

of life Growth rates in these semi-shy‐natural ponds are also comparable to estimated growth

rates13 of juvenile13 wild13 fish (McCarthy13 and13 Minckley13 1987) Modde13 and13 Haines13 (2005)

reported13 the13 greatest growth13 rates13 in the13 largest and13 deepest floodplains13 with13 the13 greatest

amount of submergent vegetation but excellent growth and survival of fish in a grow-shy‐out

pond is of little value if there is not an efficient way to collect the fish from13 the pond

(Kaeding and Osmundson 1989)

Temperature13

Bulkley and Pimentel (1983) used shuttle boxes in the laboratory to determine a

temperature preference13 for razorback suckers13 of 23-shy‐24degC13 In13 their13 studies13 razorback

suckers were found to avoid temperatures below 118 degC or above 286 degC Razorback

suckers at Bubbling Ponds Hatchery are more active in the spring and feed better as

photoperiod increases even prior to water temperatures rising (Frank Agygos personal

communication) Table 3 briefly summarizes water temperature data from13 each facility

Detailed seasonal water temperature profiles are not currently available for many

razorback grow-shy‐out sites13

Density13

Extensive studies have been conducted on commercially important species to

evaluate stocking densities and feeding rates that maximize production For these species

controlled experiments under laboratory conditions have established relationships

between temperature density and feed ration on growth (Brett 1979) but this information

is sporadic13 or non-shy‐existent for razorback suckers13 (Bays13 et al13 2005) Fish culturists13 with13

24

13

experience13 rearing13 razorback suckers13 typically13 have13 target stocking13 densities13 that13 they use

(Tables13 4 -shy‐ 5) These stocking densities have largely been determined over time by trial

and error These approximate stocking densities provide a good starting point for more

controlled13 types13 of replicated13 pond studies13

Feed ration

Razorback13 suckers are currently13 being13 fed a wide variety13 of prepared diets (Table 7)

that range from13 a slow-shy‐sinking salmon feed manufactured by Silver Cupreg to a spirulina

and krill-shy‐enhanced catfish feed made by Rangenreg Most locations are feeding 20 ndash 50

body13 weight per13 day13 Methods13 for culture13 of razorback sucker13 larvae13 in intensive13 settings13 at

fish hatcheries are well documented (Figiel 2005) and various larval fish diets have been

evaluated13 (Tyus and13 Severson 1990 Severson et al13 1992) but no standardized13 procedures

are used for feeding13 larval13 fish in13 intensive settings13

Razorback sucker larvae are also effectively reared in pond environments using

natural foods supplemented with larval fish diets and survival is high when no predators

are present13 (Mueller 2006)13 Growth rates for larval13 and early juvenile razorback13 suckers

may increase with pond fertilization Diet and physiological studies on wild razorback

suckers indicate that they feed on plankton as well as benthic organisms during their entire

life (Marsh 1987) Artificially fertilizing ponds may greatly increase production capacity

and growth rates for razorback13 sucker (Papoulias and Minckley13 1992) and warrants

further13 investigation13

Handling stress

Handling stress13 has13 been shown to13 influence growth13 rates13 Paukert13 et al (2005)

found that growth of bonytail chub was reduced by 26when compared with controls

after being13 repeatedly13 captured and handled in13 hoop13 nets13 Handling13 effects are likely13 to be

similar for razorback suckers that are repeatedly13 captured and sorted in13 a hatchery13 setting13

Razorback suckers that are handled at Willow Beach National Fish Hatchery will commonly

not eat for two weeks after handling (John Scott personal communication) This creates a

difficult situation13 for production13 facilities because13 fish13 need to be sorted to ensure13 large13

25

13

aggressive fish do not interfere with growth of smaller individuals but frequent handling

and sorting13 causes stress related reductions in13 growth13

Measuring Growth in Captive Fish

Weight is the traditional measure used to estimate growth or production in

aquaculture settings13 Groups of fish are typically13 weighed and an average individual13 weight13

is computed (Busacker et al 1990) Although this method is often logistically the easiest it

may not be the most informative for species with highly variable growth rates like

razorback suckers especially when target lengths must be reached before fish can be

stocked Weight can also be highly influenced by things like stomach fullness or

development of gonads (Busacker et al 1990) Condition factor or relative weight can also

be used to assess growth of fish but these tools may be more robust predictors of fecundity

than of growth (Anderson and Neuman 1996) For some species sexes need to be

distinguished because males and females may differ in morphology (Anderson and

Neumann 1996) Mueller (2006) analyzed growth rates based on PIT tag recaptures of 86

razorback suckers13 in High13 Levee Pond13 and13 found13 that differences13 in growth13 do not appear13

to occur until fish are over 450 mm TL at which time growth rate in males slows while

females continue to grow at a slightly higher rate This would indicate that sex may not be

an important factor to consider when examining growth rates unless the target grow-shy‐out

size is above 450 mm TL

The best measures of growth are often determined from13 the length and weight of

individuals rather than from13 groups of fish (Anderson and Nuemannn 1996) because

individual growth rates give better estimates of confidence and variance (Busacker et13 al

1990) Length frequency analysis or recapture of previously marked individuals of a known

size is likely to yield the most useful information for razorback sucker growth The success

of any of these methods depends on proper sampling procedures that are representative of

the population as a whole (Busacker et al 1990) Sampling methods that are known to be

size-shy‐biased such as trammel nets (Mueller et al 2004) or cast nets should not be used when

trying to measure growth rates13

26

13

Conclusions

For razorback sucker survival is largely associated with stocking size Additional

focused13 research13 is therefore13 needed to13 identify13 ways13 to13 increase13 growth13 rates13 of captive-shy‐

reared13 razorback sucker Growth13 rate13 in fish is controlled13 by many factors including fish

size and age temperature density and feed ration which can all be highly correlated

Growth of razorback suckers is also inherently variable which makes the task of identifying

the key factors that13 affect13 growth in13 captivity even more difficult The focus at most

razorback rearing facilities13 is production so the13 types13 of data that are13 collected13 are13 often

insufficient for detailed13 evaluations13 of individual rearing13 practices13 on growth13 Surveys of

existing13 razorback sucker13 rearing facilities indicate that culture methods vary widely and

the types of growth data13 that13 are collected are not13 standardized13 Replicated studies with

detailed information on rearing location water temperature initial stocking size stocking

density and the sizes of all fish at harvest are needed in order to compare the effects of

individual rearing practices on growth This type of research will ultimately provide both

time and cost-shy‐savings to production facilities by reducing the amount of time necessary13 for

razorback sucker to reach stocking size improving overall production efficiency

Optimum13 rearing densities for razorback sucker larvae and juveniles remain to be

determined Current stocking densities will be very useful as starting point for more

detailed studies and although optimum13 rearing densities are likely to be site-shy‐specific13

replicated studies on density will provide a valuable reference for hatchery managers

Frequency13 of sorting is another13 area that needs13 further13 research Frequent

handling13 and13 sorting13 can13 cause13 stress-shy‐related13 reductions13 in growth but not sorting can

create dominance hierarchies that further reduce growth rates of subordinate individuals

The effects13 of sorting13 on overall fish growth13 in both13 pond and13 intensive13 culture13

environments warrant further investigation Research techniques for these types of

experiments are well understood and typically utilize a matrix of replicate ponds per

variable (Bays et al 2005) In every case accurate and complete records of sampling

procedures and data collection are needed in order to interpret data and make inferences

about13 growth rates (Busacker et13 al 1990)13

27

13

Additional research is also needed to evaluate long-shy‐term13 survival of stocked fish

reared in ponds compared to fish13 reared13 in intensive13 culture13 facilities13 Exercise13

conditioning13 and predator-shy‐recognition training may also increase survival of stocked fish

and be more economically feasible than rearing fish to increasingly larger sizes prior to

stocking13 The success13 of traditional fish hatchery programs is measured largely by the

number of fish stocked but hatchery programs for endangered species must measure

success in terms of long-shy‐term13 survival and species recovery (Brannon 1993 Anders 1998)

A specific list of research recommendations follows

Specific Research13 Recommendations13

bull Use replicated studies13 to establish optimum stocking13 densities13 for ponds13 and

tanks13 that can be used as13 a starting13 point for site specific refinement

bull Determine if sortinggrading13 improves13 overall growth rates13 in both ponds13 and

intensive culture facilities13

bull Investigate the use of artificial fertilizers13 to improve growth of both juvenile

and adult razorback suckers13 in ponds13

bull Determine if the razorback sucker diet gives13 better growth rates13 than cheaper

catfish or salmon feeds

bull Evaluate growth rates13 and production potential of new intensive culture

methods13 such as13 large circular tanks13

bull Evaluate13 long-shy‐term survival of fish produced from raceways13 and circular tanks13

compared to fish reared in ponds13

bull Evaluate more effective means13 of treating13 fish diseases13

bull Evaluate factors13 other than size that may increase post-shy‐stocking13 survival such

as13 exercise conditioning13 predator recognition training or rearing13 under more

natural settings13

28

13

II The Effect of Disease Treatments on Razorback Sucker

Growth

Section13 SummaryFormalin copper sulfate potassium permanganate and13 salt are all chemicals commonly13 used13 to13 treat13 Ichthyophthirius multifiliis outbreaks in captive razorback sucker (Xyrauchen13 texanus) Weexposed 190 juvenile13 razorback suckers (127 ndash 26 mm TL) to13 5 5-shy‐day treatments with13 each13 chemical to evaluate the effects13 these chemicals13 may have on growth Fish grew an average of23513 mm TL13 during the month13 study period Fish treated with formalin grew on average13 29mm TL (03 mmday) while fish treated with copper had the lowest growth averaging 20 mmTL (021 mmday) No significant differences in13 growth were observed among fish treatedwith any of the chemicals compared to untreated fish (pgt005) Reductions in growth13 as aresult of repeated chemical treatments are not likely the cause of differences in growth ratesamong13 facilities that raise razorback suckers Repeated chemical treatments may13 have otherimpacts to overall13 fitness or long-shy‐term survival but13 these effects were not13 evident13 in our study

29

13

Introduction

Preservation13 of razorback sucker13 (Xyrauchen texanus) currently13 depends on captive13

rearing and stocking programs until permanent solutions to factors that prevent wild13

recruitment are found Low survival of stocked razorback suckers (Brooks 1986 Marsh

and Brooks 198913 Marsh and Pacey13 2005) has caused target13 sizes for stocked fish to

steadily increase in efforts to reduce predation mortality (Marsh et al 2005 Schooley and

Marsh 2007) Rearing fish to larger sizes at hatcheries comes with increased costs and

creates the need to evaluate husbandry and rearing practices that may affect fish growth

Formalin copper sulfate potassium13 permanganate and salt are all chemicals

commonly used at razorback sucker rearing facilities to treat outbreaks of the protozoan

parasite13 Ichthyophthirius multifiliis ldquoIchrdquo is one of the most pathenogenic diseases of

cultured13 freshwater13 fishes (Matthews13 2005) and causes large13 losses in captive13 populations13

of endangered razorback sucker Each of these chemicals used to treat Ich only kill the free-shy‐

swimming life stage of the parasite13 requiring13 repeated doses over several13 days depending13

on water temperature These chemicals treatments are needed to prevent loss as a result

of disease outbreaks but the cumulative effects repeated disease treatments have on

growth13 are13 unknown

Copper13 sulfate13 has13 been shown to13 significantly13 reduce13 growth13 of channel catfish13 in

production13 ponds (Rabago-shy‐Castro13 2006) but it is unknown whether13 razorback suckers13

experience similar reduced growth following copper treatment Quantifying the impacts of

disease treatments on growth will help to interpret the wide differences in growth rates

observed13 at various13 razorback sucker13 production13 facilities13 throughout the13 southwest

(Ward et al 2007) If one chemical is found to have less detrimental impacts on growth

than another then it may be preferred for use as a disease treatment We evaluated growth

rates13 of razorback suckers13 under13 replicated13 and13 controlled13 conditions13 to13 assess13 effects13 of

repeated formalin copper sulfate and potassium permanganate and salt treatments on

growth13

Methods

We captured 190 juvenile razorback suckers from13 ponds at Bubbling Ponds Fish

Hatchery AZ using hoop nets or cast nets All fish were of the same age class and

30

13

averaged 179 mm total length (TL) (range13 = 127 ndash 262 mm TL)13 These fish were13 offspring13

of captive13 razorback sucker13 broodstock held13 at Dexter13 National13 Fish Hatchery13 NM13 (2007

year class) All fish were tagged with passive integrated transponder (PIT) tags and

quarantined for one month prior to the experiment to allow fish to recover from13 tagging

and become accustomed to being held in circular tanks

At the beginning of the study all fish were weighed measured and scanned for

individual tag numbers with 19 randomly selected fish placed into each13 of 10 8-shy‐foot

diameter circular tanks (Figure 2)13 Each13 tank contained13 two13 airstones13 and13 an13 individual

biofilter with a recirculating water pump (31 litersminute) that had been operating for

at least 1 month prior to the experiment to allow bacterial colonies to become

established Two tanks were designated as a control and did not receive any chemical

treatments while the other eight tanks received formalin copper sulfate potassium13

permanganate or salt treatments at two week intervals (two tanks per chemical

treatment) Formalin copper sulfate and potassium13 permanganate were treated at 1 part

per million (ppm) and salt was applied at 30 parts per thousand (ppt) These treatment

rates are commonly used to treat13 razorback13 suckers for ich at Bubbling13 Ponds Fish13

hatchery (Frank Agygos personal communication)

Figure 213 Photo ofexperimental tankswith individualbiofilters and aeration

31

13

Each treatment consisted of a series of doses applied on Wednesday Thursday and

Friday with a 90water change between each dose Biofilters were removed from13 all

tanks and held in a separate holding facility during treatments and then replaced on the

Monday following treatments after a 90water change This schedule allowed fish to be

exposed to chemical treatments for 5 consecutive days without water quality deteriorating

This 5-shy‐day chemical treatment was repeated every two weeks from13 July to October (97

days)13 for a total of 5 5-shy‐day treatments Water temperature in the treatment tanks ranged

from13 13degC (55degF) to 32degC (91degF)

Fish were fed a fixed ration of commercial razorback diet (Silvercup 4mm13 pellet)

once daily13 (2 percent body13 weight per day13 as calculated13 by13 average initial fish weight)13

At the end of the experiment all fish were again weighed measured and scanned for

individual tag numbers Growth of fish in each treatment group was compared using

analysis of variance (ANOVA) Any mortalities13 that occurred during the13 study13 were13

replaced with previously quarantined fish of equivalent size to maintain equal densities in

each13 tank13 but growth13 data was13 only13 recorded for fish which13 survived13 the13 entire13

experiment

Results

Fish at the13 start of the experiment averaged 179 mm TL (Range13 = 127 ndash 262 mm)

with no significant differences in fish length among treatment groups (F(4189) = 00183 p

gt 0999 ANOVA) On average fish grew 235 mm TL (024 mmday) during the 3 month

study13 Fish in tanks13 treated with formalin had the highest growth averaging 29 mm TL (03

mmday) while fish in tanks treated with copper had the lowest growth averaging 20 mm

TL (021 mmday) Fish in the control tanks averaged 213 mm TL in growth (022

mmday) (Figure13 3)13 Formalin-shy‐treated fish grew13 significantly faster than13 any other

treatment group but no13 significant differences in growth13 in length13 or weight were13

observed among fish treated with any of the chemicals compared to untreated (control)

fish (pgt005 ANOVA)

32

13

Figure 313 Average growthof razorback suckersexposed to a series of 5 5-shy‐day chemical treatmentsover a 97-shy‐day13 periodError bars representstandard error

Discussion13

Growth13 rates13 observed13 in our study13 (021 ndash 03 mmday) are low compared to those

reported13 in other13 studies13 of razorback sucker13 growth13 (0213 ndash 18 mmday) (Ward et al

2007) Using recirculating water systems for our study required filters to be removed and

replaced during treatments Stress to fish caused by removing and replacing filters within

the tanks as well as repeated water changes may have led to overall higher stress and

reduced growth rates compared to those reported for unconfined fish Growth in fish is

highly variable and is affected by many different physiological and environmental factors

including fish size density temperature amount of space and food (Brett 1979) We

strived to control each of these factors but other factors may have also influenced growth

in our experimental tanks During mid-shy‐summer water temperatures in the treatment

tanks reached 32degC (91degF) At these warm13 temperatures fish are very susceptible to

bacterial13 infections13 The slightly higher growth exhibited by fish in the formalin and

potassium13 permanganate treatments may have been the result of these two chemicals

33

13

being effective at controlling bacterial infections The differences in growth we measured

among treatment groups were not statistically significant and do not appear13 biologically13

meaningful during the relatively short duration of this study (97 days) although the

cumulative effects of slightly reduced growth could be biologically meaningful over longer

time frames

Reductions in growth13 as a result13 o repeated chemical treatments are not likely the

cause of differences in growth rates among facilities that raise razorback suckers

Repeated chemical treatments may have other impacts to overall fitness or long-shy‐term13

survival but these13 effects13 were13 not evident in our study It is more likely that the parasite

outbreaks themselves are the cause of different growth rates among razorback rearing

facilities rather than the chemical treatments used to treat the parasites We recommend

that hatchery managers continue to use the chemicals that are most effective at controlling

ldquoIchrdquo13 at their individual13 facilities

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower Colorado Rive Multi-shy‐species13

Conservation Plan under Work Task C10 We thank Ty Wolters and Tom13 Burke for their

support of this research and Frank Agygos and Dave Billingsly of the Bubbling Ponds Fish

Hatchery13 for their13 technical assistance13 and13 help with13 collecting13 fish

34

13

III13 Razorback Growth Rates at Bubbling Ponds ndash 2009-shy‐2011

Section13 SummaryExperimental studies at Bubbling Ponds Fish Hatchery AZ have strived to understand

factors that affect razorback sucker growth in captivity and identify ways to improve growthrates and maximize size at release Rather than performing experimental studies that wouldrequire major13 rearrangement (and likely reduced production)13 of hatchery operations our13 studies13 used normal variation in production techniques13 and practices13 to isolate factors13 thatmay modify growth rates

Our initial work identified razorback13 growth rates in13 lined ponds at standard fishdensity as 026 to13 028mmday (789 to 843 mmmonth) No significant differences in growthrate were observed among fish that had been in the pond only during the winter13 periodcompared to fish that had been in the pond the entire year indicating that water temperatures13 at Bubbling Ponds are high enough to allow fish to incorporate feed effectively year-shy‐roundHowever these growth rates are lower than most values reported from the literature fromnatural or semi-shy‐natural pond environments No significant differences in13 growth rate wereobserved13 between large and13 small fish13 within the 150 ndash 29 mm TL13 size range Additional worksuggests13 that razorback suckers13 tagged at over 300 mm TL had reduced growth rates (024mmday 73 mmmonth) as would be expected according to a typical Von13 Bertalanfy growthcurve although growth rates13 were only slightly less13 than the average growth rate for thehatchery (027513 mmday 82513 mmmonth)

Sorting13 to13 separate small fish from large fish after the first year of growth is practicedesigned13 to allow smaller fish to ldquocatch uprdquo to larger fish We found that13 this technique doesappear to13 improve growth rates of smaller fish Growth rates of sorted small razorback suckers(029 mmday 87mmmonth)13 were equal to that13 of larger13 fish (028 mmday 8413 mmmonth)indicating that sorting may have helped to offset their original slower growth trajectory

Bubbling Ponds Fish Hatchery grows razorbacks in 6 long deep ponds lined with heavyplastic 2 long deep13 earthen13 (unlined) ponds and three wide shallow earthen ponds The wideshallow ponds13 have historically produced very large fish at low density but have been found tomaintain much lower fish numbers than deeper ponds We found13 that growth13 rates ofrazorbacks kept at high density (4-shy‐700013 fish)13 in a wide shallow pond grew extremely slowly(024 mmday 726 mmmonth) This growth rate is among the slowest of any fish over theyears of our study and demonstrates that13 though the large ponds may produce large fish at lowdensity13 they are unable to overcome high13 fish13 densities

Finally one of the major factors influencing13 fish13 growth13 in hatcheries is disease onemajor summer-shy‐time disease at13 Bubbling Ponds is the ectoparasite Ich (Ichthiopthirusmultifiliis) To investigate the impact Ich has on razorback growth we eradicated fish from thespring and water conveyance ditch that supplies13 water to the hatchery using Rotenone This13 restoration effort was fairly short-shy‐lived (Ich returned to the hatchery within four months) but

35

13

growth13 rates of fish13 reared for four months without Ich present (031 mmday 92 mmmonth)were significantly higher than the following 8 months of growth for those same fish (022mmday 65 mmmonth) This disease-shy‐free growth rate is in fact faster than any13 otherprevious growth rates observed at the hatchery in our study

We conclude that growth rates at the Bubbling Ponds Fish Hatchery are likely as highas possible given the pond densities required to13 meet production goals and the Ich-shy‐infestedwater13 that feeds the facility Sorting practices are successful in helping as many fish as possiblereach stocking length as fast as possible Unlined ponds may be able to grow large fish at lowdensities but whatever factors allow for that growth13 are not able13 to overcome13 high fish densityThus the large lower ponds at Bubbling Ponds may be better utilized via renovation to13 deepenand line them

Disease is the most important factor limiting growth as may be expected to be the caseat many13 hatcheries While the spring renovation was not13 a complete success13 the dramaticreduction of fish populations in that habitat was enough to dramatically13 reduce13 the13 occurrenceof Ich at the hatchery13 Such open spring13 systems feeding a hatchery are a misfortune that canbe expected to transmit disease so we suggest that renovating the spring again to combat13 IchImproved techniques to divert water from13 the springs and more throuough treatment ofstream-shy‐side vegetation may improve the success of chemical treatment Successful renovationwould likely both improve growth rates and reduce chemical costs associated with treating Ichoutbreaks Even13 if complete renovation13 is impossible or impractical an13 effort to reduceinvasive fish density in the springs13 which act a vector for the parasite(and thereby reduce thelikelihood of13 Ich being transmitted into ponds) may still13 show dramatic improvements

36

13

Introduction

Conservation efforts13 for razorback sucker13 (Xyrauchen texanus)13 currently13 depend on

captive rearing and stocking programs Low survival of stocked razorback suckers (Brooks

1986 Marsh13 and13 Brooks13 1989 Marsh13 and13 Pacey13 2005) has13 caused13 target sizes for stocked13

fish to steadily increase in efforts to reduce predation mortality13 (Marsh13 et al13 2005

Schooley and Marsh 2007) Rearing fish to larger sizes at hatcheries comes with increased

costs and creates the need to evaluate husbandry and rearing practices that may affect fish

growth13 We evaluated growth13 rates13 of individual razorback suckers13 in ponds13 at Bubbling

Ponds Fish Hatchery13 using Passive Integrated13 Transponder (PIT) tags13 to13 obtain13 precise

growth information for individual fish so that valid comparisons of growth rates as related

to rearing practices can be made

Due to the critical nature of the razorback sucker stocking program we did not

design experimental studies that would require major rearrangement and potentially

reduce production of hatchery operations Instead our studies used normal variation in

production techniques and practices to isolate factors that may modify growth rates

Though this methodology dramatically limits replication and may limit our ability to

directly13 attribute13 differences in growth13 rates13 to13 the13 variables13 we13 investigate13 we13 were13 able13

to accomplish research goals without altering hatchery operations or impacting

production

From13 2009 through 2011 we conducted a series of observational13 growth13 studies to

determine growth rates of individual razorbacks at Bubbling Ponds The first set of

experiments included13 identifying13 growth13 rates13 in lined13 and13 unlined13 ponds determining

growth13 rates13 of fish at different13 sizes13 in13 relation13 to sorting13 practices and monitoring

razorback growth rates after removing the source of the ectoparasite13 Ich (Ichthiopthirus

multifiliis) from13 the hatchery water source13

Razorback growth rate in lined ponds

Our first growth study documented individual growth rates at normal density in 11

million gallon lined ponds13 over two13 years13 This is the standard13 grow-shy‐out process for

razorbacks13 at Bubbling Ponds We monitored growth of fish for a variety13 of sizes and13 the13

37

13

amount of time in a pond during the growing season These13 data give a snapshot of growth13

rates13 at the13 facility13 and13 provide13 the basis for comparisons throughout our study

Growth rate13 in an unlined pond

In addition13 to 6 ponds lined with heavy plastic13 sheeting13 Bubbling Ponds Fish13

Hatchery maintains two narrow and deep (same dimensions as lined ponds13 Figure13 4)13 and13

three large13 shallow unlined ponds These earthen13 ponds typically have vegetation and

associated aquatic invertebrates that may better simulate natural environments by

providing cover and improved food diversity or quality Therefore these unlined ponds

may be expected to produce higher growth rates and potentially improved survival that is

more similar to growth rates observed in more natural grow-shy‐out facilities13 Historically13 the13

large13 shallow13 ponds have produced very large fish when13 utilized at low13 fish density13 The

narrow13 deep earthen13 ponds are13 used to grow13 fry13 at high density in their first13 year of life

The major downside to unlined ponds is the difficulty in harvesting fish where a lined

pond might take 8-shy‐1013 people13 a half13 day13 to13 harvest13 lined13 ponds13 require13 intensive13 weeding13

to allow seines to be pulled and therefore require many more personnel-shy‐hours13 In addition13

to harvest challenges the shallow earthen ponds tend to suffer from13 dissolved oxygen

crashes during the summer Unlined ponds also may maintain higher13 populations13 of non-shy‐

target species such as bluegill sunfish mosquito fish and bullfrog tadpoles We measured

growth rates of suckers in a large shallow earthen pond for comparison to growth in lined

ponds13

Figure13 4 Lined13 and13 earthen ponds13 of similar dimensions (approx 1000000 gallons first

and second panels) and a large13 shallow13 earthen13 pond (third panel)

38

13

Effect of sorting on growth

Razorback13 suckers13 are13 currently13 sorted13 after their first13 year of growth13 They are13

typically removed from13 one of the13 upper earthen13 ponds and13 split into13 two13 lined13 ponds for

subsequent grow-shy‐out13 The larger13 fish (gt approximately 140 mm) are placed into one pond

and the smaller individuals in another It is possible that the larger fish were more

aggressive or adept13 at taking food so this sorting process is intended to allow smaller fish

to improve their growth rate

Effect of Ich on razorback sucker growth rates

We13 evaluated13 growth13 rates13 of razorback sucker13 in the13 presence13 and absence of the

ectoparasite13 Ich (Ichthiopthirus multifiliis) Ich outbreaks can occur in wild populations13 but

hatcheries13 have13 proven excellent locations13 for Ich because13 of very high fish densities13 which13

facilitate13 the13 transfer13 of Ich13 between13 fish This common fish parasite causes direct mortality13

to razorback13 suckers as well13 as secondary bacterial13 infections13

The open spring and13 ditch13 which13 provides water to the Bubbling13 Ponds Hatchery

has long13 been infested with mosquitofish (Gambusia affinis) that harbor13 the13 Ich parasite13

and allow13 it13 to enter the hatchery with incoming13 water13 The solution13 to13 the13 Ich problem13

was to remove the mosquitofish host using13 Rotenone Razorback13 sucker growth13 rates were13

then tracked in13 the absence of this parasite for 4 months and compared with growth rates

after Ich returned to the pond and from13 previous years

Methods

Razorback growth rate in lined ponds

On May 14 2008 141 razorback suckers were tagged with 12 mm PIT tags (1342

kHz) and placed in Pond 3 (approximately 1100000 gallons13 Figure13 4)13 at Bubbling13 Ponds

Fish Hatchery Fifty-shy‐three of these tags were recovered two months later when a large

Ichthyophthirius multifilis (Ich) outbreak killed many fish in the pond On October 15 2008

an additional13 145 PIT tagged13 fish were13 also placed into Pond13 3 On13 May13 14 2009 Pond13 3

was harvested and a total13 of 141 PIT tagged fish were recovered13 Of the tagged fish13 26 fish

had13 been13 in the13 pond since May13 of 2008 (378 days13 o growth) and 115 had been13 in13 the

39

13 40

pond since October13 15 2008 (211 days13 of growth) Numbers of fish in Pond 3 after the Ich

outbreak and for the majority of the period of growth were between 3 000 and 4000 fish

A Hobotempreg temperature13 logger13 was13 also13 installed13 in Pond 3 one meter below the water

surface13 near13 the13 outflow and13 recorded water temperature every 3 hours to allow analysis

of the effects of water temperature on growth rate (Figure13 5) This Hobotemp data is

representative of other pond temperatures throughout this study

In a second experiment 210 adult13 razorback suckers13 were13 PIT tagged13 on13 May 14

2009 and13 placed13 into13 Pond13 3 upper to13 evaluate13 growth13 rates13 of larger13 razorback suckers13 at

Bubbling13 Ponds Hatchery13 under current13 rearing13 conditions13 Size of these fish at tagging13

was (mean = 285 mm range = 205 ndash 396 mm) These fish remained in the pond for 257

days and were harvested on Jan 25 2010 to provide information on growth rates of larger

razorback suckers13 under13 current rearing conditions

Figure 513 Temperatures (degC) inrearing pond at BubblingPonds Hatchery from July toSept 2009 (top graph)13 andfrom Nov to Dec 2009 (Lowergraph) Temperaturesrecorded with a Hobotempregremote data logger13 every 3hours

13

Growth rate13 in an unlined pond

To document razorback sucker growth in earthen ponds we introduced13 225 tagged13

razorback suckers13 into13 Pond13 1 lower13 (Figure 4) in February 3 2010 Additional tagged fish

from13 other studies were added to the pond throughout the growing season and the density

of 1 lower reached a maximum13 of nearly 7000 fish in early summer 2010 Density was

reduced to approximately 6000 fish by capturing fish with hoop nets on June 3 2010 54 of

these fish were tagged fish and returned to 1 lower after being weighed and measured The

pond was harvested on January13 2713 2011 and a total13 of 254 tagged fish out13 of 4296 fish

total were removed from13 the pond The pond was harvested on January 27 2011 (358 days13

of growth) and the tagged fish were weighed and measured Total number of razorbacks in

the pond at harvest13 was 4296

Effect of sorting practices on growth rates

On March 1113 200913 Pond13 5 upper was13 harvested13 and13 split into13 two13 separate13 groups

Two hundred of the smaller fish (average size = 122 mm TL) were PIT tagged and placed

into13 Pond13 7 upper and13 200 of the13 larger13 fish (average = 160 mm TL) were PIT tagged and

placed int Pond13 8 upper Density13 in Pond13 7 was13 4500 fish and13 in Pond13 8 there13 were13 6500

fish These ponds were then harvested after 1 year and growth rates were compared to

give information on the effects of current sorting practices Hobotempreg temperature

loggers were installed in13 Ponds 7 and13 8 during13 the13 grow-shy‐out period with13 water13

temperature recorded every 2 hours13 (Figure13 6)

Effect of Ich on razorback sucker growth rates

Bubbling Ponds spring was treated with Rotenone (CFT Legumine 5) at a

concentration of 2 ppm13 to remove all mosquitofish from13 the spring The treatment

consisted of two treatments 6 hours in duration on two consecutive days (April 12 -shy‐ 13)

using13 drip13 stations13 and13 backpack sprayers13 followed13 by13 an13 additional 6 hours13 of

detoxification using sodium13 permanganate Although 12 mosquitofish were captured in the

spring pond the week following the treatments subsequent minnow trapping (20 traps

checked13 daily13 for 3 weeks) did not capture any additional fish until August 11 2010 when

41

13

juvenile mosquitofish were again detected in the spring pond Minnow traps have

subsequently been set daily with several hundred individuals removed To evaluate if Ich

was also again present in the spring we captured 15 mosquitofish from13 the spring pond on

three separate days and placed them13 in an aquaria at 25 degC with 5 longfin dace known to be

free of Ich These fish were monitored for 2 weeks with no signs of Ich developing This

indicates that even though mosquitofish have returned to the spring pond the parasite is no

longer present13 although how13 long13 this condition13 will13 persist13 is unknown13

On May 1113 201013 200 juvenile razorback13 suckers were harvested out13 of Pond 5

upper (2009 year Class from13 Dexter National Fish Hatchery) and were PIT tagged and

placed into Pond 8 to evaluate if growth rates at bubbling ponds hatchery have improved

following the renovation of the spring and the removal of the Ich parasite Unfortunately13

on Sept13 8 2010 Ich was13 again13 detected13 in Pond 8 and the pond was immediately seined

and 74 tagged fish were measured to obtain growth information for the 4-shy‐month period

during13 which13 the13 pond13 was13 Ich-shy‐free13

Figure13 6 Temperatures (degC) in rearingponds 7 and 8 at Bubbling Ponds Hatchery13 from March 2009 ndash March 201013 pond 7(top13 graph)13 and13 pond 8 (Lower13 graph)13 Temperatures recorded with a Hobotempregremote data logger every 3 hours

42

13

Results

Growth in Lined Ponds

Razorback suckers13 that had been13 in13 Pond 8 upper for the13 entire13 year13 grew an13

average of 0263 mmday (789 mmmonth) and razorback suckers that had been in the

pond for 7 months (Oct -shy‐ May) grew13 on13 average of 028 mmday (843 mmmonth) (Figure13

7) These growth13 rates13 did not significantly13 differ Fish density13 in Pond 3 during13 the13

majority of the growth period was13 00032 ndash 00036 fishgallon13 Additionally no13 significant

differences in growth rate were observed between fish smaller than 210 mm TL and fish

larger than 210 mm TL when all recaptured fish were combined

We also measured the growth rate of very large fish in a lined pond On Jan13 2513 201013

156 adult fish with PIT tags were recovered from13 Pond 3 upper13 These fish were13 in the13

pond for 257 days and experienced an average13 growth13 rate13 of 024mmday or 73

mmmonth (Figure13 7)13 This growth13 rate13 is slightly13 lower13 than13 the13 average13 growth13 rate13

observed13 at Bubbling13 Ponds Hatchery in other studies (0275 mmday 825 mmmonth)

but may not be biologically meaningful We would expect larger13 fish to13 have13 reduced

growth rates according to a typical Von Bertalanfy growth model (Bertalanffy 1957) but it

appears that13 over the size range we evaluated (300 -shy‐ 450 mm TL) growth rates have not

slowed significantly compared to that of smaller13 fish grown at Bubbling Ponds13 Hatchery

Growth13 of razorback suckers13 is known13 to13 slow as13 fish reach13 larger13 sizes but it appears13 this13

reduced growth rate may not really start to be biologically meaningful at Bubbling Ponds

Hatchery13 until razorback suckers13 exceed 450 mm TL

Growth in unlined ponds

Growth13 rates13 for the13 fish recaptured13 during13 the Pond 1 lower13 thinning13 (120 days13 in

the pond) was 024 plusmn 003 mmday (729 plusmn 090 mmmonth) (Figure13 8)13 Fish13 that were13 in

the pond for nearly the entire year grew13 an13 average13 of 024 plusmn 001 mmday (726 plusmn 027

mmmonth) These growth rates are surprisingly the lowest measured growth rates for

any part of our study and differ significantly from13 every other measured growth rate

except very large13 fish (Figure13 9)13 Separating13 out13 large fish that13 were in13 the pond for the

entire year makes no difference fish that were added to the pond at TL lt300 mm grew

43

13

Gro

wth

Rat

e (m

md

ay)

020

026

032

0244 plusmn 001 mmday (733 plusmn 028 mmmonth) and and those with TL gt= 300 mm at the

start of the experiment grew 022 plusmn 003 mmday (651 plusmn 101 mmmonth)

Razorback Growth Rates in Lined Ponds

Figure 7 Growth ofrazorback suckers in(mmday plusmn standard error)in Pond 8 upper in 2008-shy‐2009 An ANOVA did notdetect any significantdifferences

7 Months Full Year 300+ mm fish

Effects of sorting on growth

One hundred and seventy five tagged razorback suckers were recovered from13 Pond

8 upper13 on March13 24 2010 (378 days13 of growth)13 These were13 the13 larger sorted13 fish (gt140

mm TL) that came out of Pond13 5 on March13 11 2009 One13 hundred and13 twenty13 two13 tagged13

razorback suckers were also recovered from13 Pond13 7 upper on March13 31 2010 (385 days13 of

growth)13 These were13 the13 smaller sorted13 fish (lt140 mm TL) that came out of Pond13 5 on

March 1113 200913 No significant differences in growth rate (mmday) were observed among

larger fish in Pond 8 and smaller fish in Pond 7 (pgt005 ANOVA) (Figure 10)13 indicating

that13 sorting may have helped to offset the original slower growth trajectory of the smaller

fish Temperatures of Ponds 7 and 8 upper remained similar throughout the year13 (Figure

5)

44

13

13

13

Gro

wth

Rat

e (m

md

ay)

Gro

wth

Rat

e (m

md

ay)

020

026

032

020

026

032

Razorback Growth in an Unlined Pond

Figure 8 Growth of razorbacksuckers (mmday plusmn standard error) in Pond 1 lower (an unlined pond)in 2010-shy‐2011 An ANOVA did notdetect any significant differences

6 Months 12 Months lt 300 mm Fish 300+ mm Fish Growth Growth

Lined vs Earthen Ponds 1 year of growth

Figure 9 Growth of razorbacksuckers (mmday plusmn standard error) in lined and unlined ponds A t-shy‐test13 did not detect a significantdifference

Lined Pond Unlined Pond 1 Yr Growth 1 Yr Growth

45

13

Effect of Sorting G

row

th R

ate

(mm

day

) G

row

th R

ate

(mm

day

)

032

020

026

032

020

026

Smaller Fish Larger Fish

Effect of Ich

Figure 10 Average growthof razorback suckers(mmday plusmn standard error)that were size-shy‐sorted intosmall fish (pond 7) and largefish (pond 8) populations At-shy‐test did not detect asignificant difference

Figure 11 Average growth ofrazorback suckers (mmday plusmnstandard error) after Ich wasremovd from the hatcheryrsquos springand after Ich was again detected inthe pond The growth rate withoutIch is significantly higher than boththe rate after Ich and the ourstudyrsquos average annual growth ratein lined ponds (ANOVA p =00003)

Growth without Ich Growth With Ich Average Annual 4 months 4 months Growth Rate

46

13

Effect of Ich on razorback sucker growth rates

Seventy-shy‐four13 tagged13 razorback suckers13 were13 recovered from13 Pond 8 on September

15 2010 These fish had13 been13 in the pond for 4 months and experienced a growth rate of

032 mmday or 97 mmmonth (Figure13 11)13 This growth13 rate13 is significantly higher (p =

005 two sample t-shy‐test) than the mean growth rate for the same group13 of tagged fish after

Ich detection (022 mmday or 65 mmmonth) and significantly higher than any other

individual growth13 rates13 observed13 to13 date13 at Bubbling13 Ponds Hatchery13 (Figure13 11)13 If this13

growth13 rate13 were13 extended throughout13 the entire13 year13 fish on average from13 Ich-shy‐free13 ponds13

would be 16 mm longer than fish from13 ponds infested with Ich Studies conducted at

Bubbling Ponds hatchery in 2008 (Ward 2008) did not reveal any effects of the treatment

chemicals on razorback sucker growth rates so it13 is likely that13 the parasite outbreaks

themselves are causing reducing growth rates rather than the chemicals used to treat the

parasites13

Conclusions

Our results suggest that under typical hatchery operations (maximizing number of

fish produced)13 the growth13 rate13 of razorback13 suckers13 is relatively13 consistent at Bubbling13

Ponds hatchery13 at 02-shy‐03 mmday (6-shy‐9 mmmonth)13 but is lower than growth13 rates13 at

other13 facilities (02 ndash 18 mmday Ward et al 2007)13 This growth13 rate13 has13 been13 constant in

both lined and unlined ponds and at all fish densities we were able to measure To achieve13

growth13 rates13 substantially higher than this will likely require13 significant changes in rearing

practices that may not be practical in order to reach numerical production13 goals

Temperature is a key variable in fish growth but seasonal growth patterns

described13 above13 (Figure13 5) demonstrate that water temperatures are high enough in

winter to maintain razorback growth Differences in water temperature by season

currently13 do not fluctuate more than 10degC at Bubbling Ponds because of the continuous

supply of water flowing through each pond (approx 225 gallonsmin) These high water

flows appear to keep pond temperatures within the thermal preference13 for razorback

suckers13 (1213 -shy‐ 28 degC Bulkley and Pimentel 1983) throughout the entire year with

temperatures rarely dropping13 below 16deg13 C (Figures 513 6)13

47

13

Fish density is another key variable in fish growth and though the number of fish in

a pond during our study ranged from13 3000 to 700013 fish we13 did not find any13 correlation13

between13 density and growth rate13 This might yield two conclusions First13 razorback

growth13 may be changed equally13 by13 densities13 at the13 hatchery13 (ie13 a density13 of 3000 fish in a

pond is as stressful13 for razorbacks as a density13 of 7000 fish) An alternative is that other

factors13 such as disease outbreaks have13 stronger13 control over fish growth13 than13 density13

Fish density13 would13 have13 to13 be13 experimentally manipulated to test13 this13 and hatchery

operations (producing the maximum13 number of fish) prevented our manipulating density13

in ponds for this13 work The trouble with manipulating density demonstrates the difficulties

associated with changing13 hatchery13 practices experimenting with density would have

prevented BPH from13 meeting13 production13 goals Given that the stocking of smaller

razorbacks has met with very little success perhaps BPH goals could be changed from13

producing 12000 fish at 300+ mm per year to a smaller number of very large fish each

year Growing13 fewer13 larger13 fish could potentially be accomplished in the same time frame

as more smaller fish but a better understanding of how density alters growth rate would

be required to be confident13 of this

The very slow growth13 in the13 earthen13 unlined13 Pond 1 lower13 was very surprising We13

had13 anticipated13 that the13 diversified diet13 cover and13 other13 habitat features13 provided by13

unlined ponds would yield dramatically increased growth rates However these traits were

not enough to offset high fish densities and in fact the unlined pond in our study13 suffered

mortality to bring densities down to that observed normally in lined ponds

Our data13 suggest13 that razorbacks13 sucker13 growth13 rates13 are13 higher in lined13 ponds13

However we13 think the reasons13 for the13 very slow growth we observed13 in the13 unlined13 pond13

in our study13 is instead13 linked13 to13 the13 usage13 of Pond 1 lower13 during13 the13 study13 rather13 than13

intrinsic13 slow growth13 in earthen13 ponds First the pond was at extremely high density for at

least part of the study The volume of Pond 1 lower has not been estimated but hatchery

managers suggest 1500-shy‐2000 fish is an appropriate number of individuals so this pond

was at a very high density for much of the experiment Second dissolved oxygen is often

very low in the13 large13 earthen13 ponds during the heat of summer much lower than that of

lined ponds This will both limit the number of fish that can survive in the pond and almost

certainly13 increases stress13 of these13 fish potentially13 reducing growth13 The DO crashes also13

48

13

limit the amount of feed hatchery managers can give fish in these ponds sometimes for

days or weeks at a time which further reduces growth during warm13 weather

Our data13 suggests that13 growth rates at the Bubbling13 Ponds Fish Hatchery are likely

as high as possible given13 the pond densities required to meet production goals and the Ich-shy‐

infested water that feeds the facility Sorting practices are successful in helping as many

fish as possible reach stocking length as fast as possible Unlined ponds may be able to

grow13 large13 fish at low13 densities13 but whatever factors allow13 for that13 growth are not13 able to

overcome high fish density The removal of invasive13 fis that act as13 a host for the13 parasite13

Ich fish from13 the Bubbling13 Ponds spring13 allowed the highest13 growth rate at 032 mmday13

(96 mmmonth) but that growth rate decreased again as Ich re-shy‐infested13 the13 hatchery13

Consistently13 achieving13 growth13 rates13 as high or substantially13 higher than13 this13 will likely13

require13 significant changes in rearing practices that may not be practical in order to13 reach13

numerical production13 goals

Two major changes that might result in higher growth rates are substantially

reducing fish density and modifying the way spring water is delivered to the facility (via

either repeated chemical treatments or enclosed concrete water diversions) to eliminate

Ich from13 the hatchery source water Other potential changes not address by our work

include13 flow-shy‐training razorbacks much previous literature including MSCP-shy‐funded13 work

on razorback suckers13 suggests13 that fish growing13 in flowing water will grow13 faster than fish

in still water (Jorgensen and Jobling 1994) Furthermore there are a wide variety of

potential benefits associated with growing13 fish13 in flowing13 water in addition13 to increased

growth13 rates13 (Davidson13 199713 Castro13 et al13 2011) Another option13 for increasing13 growth13

rates13 include13 changing to13 intensive13 culture13 in large circular13 tanks

Finally given that the stocking of smaller razorbacks has met with very little

success13 perhaps13 BPH13 goals13 could13 be13 changed from13 producing 12000 fish at 300+ mm per

year to a smaller number of very large fish each year Growing fewer larger fish could

potentially be accomplished in the same time frame as more smaller fish but a better

understanding13 of how density13 alters growth13 rate13 would13 be13 required to13 be13 confident of this

49

13

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower13 Colorado13 River Multi-shy‐Species13

Conservation Program13 (LCRMSCP) under Work Task C10 We13 thank Ty Wolters13 Tom13

Burke13 and Eric13 Volkman for their support of this research and Frank Agygos and Dave

Billingsly13 of the Bubbling13 Ponds Fish Hatchery13 for their willingness to participate in13 this

research13 and13 for their technical assistance We also thank the LCRMSCP fish group from13

Boulder City13 NV for their assistance with harvesting13 ponds and tagging13 fish13

50

13

Literature13 CitedAnders P J 1998 Conservation aquaculture and endangered species can objective science13

prevail13 over risk13 anxiety Fisheries 23(11) 28-shy‐31

Anderson R O and R M Nuemann 1996 Length weight and associated structural indicesPages 447 ndash 482 in B R Murphy13 and D13 W Willis13 editors13 Fisheries techniques13 2ndedtion American Fisheries13 Society13 Bethesda13 Maryland

Bain M B J T Finn and H E Brooks 1988 Streamflow regulation and fish communitystructure13 Ecology13 69382-shy‐392

Bays J H Zarbock R Whitman and T Murphy 2005 Conceptual design and managementof native13 fish refugia on the13 lower13 Colorado13 River In13 CL Spring13 and13 S Leoneditors Proceedings of two symposia Restoring native fish to the lower ColoradoRiver13 interactions13 of native and non-shy‐native13 fishes 13ndash1413 July13 1999 Las13 Vegas13 Nevada13 Restoring13 natural function within a modified riverine environment thelower Colorado River13 8ndash913 July13 1998 U S Fish and13 Wildlife13 Service Southwestern13 Region Albuquerque New Mexico Pages 167-shy‐177

Bertalanffy L Von 1957 Quantitative laws in metabolism13 and growth13 Q Rev Biology 32217 ndash 231

Bingham T B Scheer and C McAda 2003 Propagation facilities in Grand Valley (24 RoadHatchery Horsethief13 Ponds and13 grow-shy‐out ponds) for captive13 rearing13 ofendangered13 fishes for the13 upper13 Colorado13 River basin13 Colorado River RecoveryProgram FY2003 annual project report13 US Fish and13 Wildlife13 Service GrandJunction13 4pp

Birchell G J and K Christopherson 2004 Survival growth and recruitment of larval andjuvenile razorback13 sucker (Xyrauchen texanus) introduced13 into13 floodplain13 depressions13 of the13 Green River Utah13 Final report13 Upper13 Colorado13 RiverEndangered Fish Recovery Program13 Project No C-shy‐6RZ Publication Number 04-shy‐1513 Utah13 Division of Wildlife13 Resources Salt Lake13 City13 Utah13 67 pages

Brannon E L 1993 The perpetual oversight of hatchery programs Fishery Research 1819-shy‐27

Brett J R 1979 Environmental Factors and growth pages 599-shy‐67513 InW S Hoar13 D13 J13 Randall and J R Brett (eds) Fish Physiology Volume 8 Bioenergetics and GrowthAcademic Press New York

Brooks J E 1986 Annual reintroduction and monitoring report for razorback suckerXyrauchen texanus in the Gila River Basin Arizona 1985 US Fish and WildlifeService13 Offices of Endangered13 Species and Fishery13 Resources Albuquerque 23 pp

51

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Brunson13 R E and K D13 Christopherson13 200513 Larval13 razorback13 sucker and bonytailsurvival and13 growth13 in the13 presence13 of nonnative13 fish in the13 Baeser13 floodplainwetland of the middle Green River Final report prepared for Upper13 Colorado RiverBasin Endangered Fish Recovery Program Project No C-shy‐6-shy‐rz-shy‐bt Publication13 No 05-shy‐26 Utah13 Division of Wildlife13 Resources13 Vernal13 32 pp

Bulkley R V and R Pimentel 1983 Temperature preference and avoidance by adultrazorback suckers Transactions of the American Fisheries Society 112601-shy‐607

Burke13 T13 199513 Rearing13 wild razorback13 sucker larvae in13 lake-shy‐side13 backwaters13 LakeMohave ArizonaNevada Proceedings of the Desert Fishes Council 2635

Busacker G P I R Adelman and E M Goolish13 199013 Growth13 Pages 363 ndash 387 in C BSchreck and p B Moyle editors Methods for fish biology American FisheriesSociety Bethesda Maryland

Castro V B Grisdale-shy‐Helland S J Helland T Kristensen S M Jorgensen J Helgrud13 GClaireaux A P Farrell A Krasnov and H Takle 2011 Aerobic training stimulatesgrowth and promotes disease resistance in Atlantic salmon (Salmo salar)Comparative Biochemistry and Physiology -shy‐ Part A Molecular amp IntegrativePhysiology13 160(2) 278-shy‐290

Czapla T E 2002 Facilities plan for the production of endangered fishes to meet statestocking13 plans13 as13 part of the13 Upper13 Colorado13 River Endangered13 Fish RecoveryProgram Upper Colorado River Basin Recovery Implementation Program US Fishand Wildlife Service13 Denver13 9 pp

Davidson W 1997 The effects13 of exercise13 training on teleost fish a review of recentliterature Comput Biochem Physiol 117A67ndash75

Figiel Jr C R 2005 Annual report fiscal year 2004 Willow Beach National13 Fish HatcheryUS Fish and Wildlife13 Service Willow Beach 17 pp

Figiel Jr C R M E Ulibarri G Carmichael J Seals and J N Hanson 2005 Intensive13 fish13 culture of warmwater native fishes at a coldwater fish hatchery Pages 164-shy‐16613 inProceedings of two symposia restoring native fish to the lower Colorado13 River13 interaction13 of native13 and13 non-shy‐native13 fishes July13 13-shy‐1413 1999 Las Vegas Nevada USFish and Wildlife Service Southwest Region Albuquerque New Mexico

Gerking13 S D 1978 Ecology of freshwater fish13 production13 Halstead Press13 New13 York

Gustafson W and Q Bradwisch 2000 Wahweap operation and maintenance -shy‐-shy‐ UtahColorado River Recovery Program FY 2000 annual project report Project No 29cUtah13 Division of Wildlife13 Resources Page AZ 3pp

52

13

Hamman R L 1985 Induced spawning of hatchery-shy‐reared13 razorback sucker ProgressivFish Culturist 47(3) 187-shy‐189

Hanson J N 1996 Annual report fiscal year 1996 Willow Beach National Fish HatcheryUS Fish and Wildlife Service13 Willow Beach 9pp

Irving D S Seversen and M Montagne 2004 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2004 annual project13 report Report No 29b US Fish and13 Wildlife13 Service Vernal 3pp

Jorgensen E H and13 M Jobling 1994 Feeding and13 growth13 of exercised13 and13 unexercised13 juvenile Atlantic salmon in freshwater and performance after transfer to seawaterAquaculture International 2 154-shy‐164

Kaeding L R and D B Osmundson 198913 Colorado13 Squawfish13 and13 razorback sucker grow-shy‐out pond studies as part of conservation measures for the green mountain andRuedi reservoir water sales Final report for agreement number 6-shy‐AA-shy‐60-shy‐00150

Koebele13 B P13 198513 Growth and the size hierarchy effect an experimental assessment ofthree proposed mechanisms activity differences disproportional food acquisition13 pysiological stress Environmental Biology of Fishes 12 181-shy‐188

Kretschmann A E and L L Leslie 2006 Razorback sucker (Xyrauchen texanus) status13 reproduction and recruitment in Senator Wash Reservoir CA Final Report13 to USBurea of Reclamation Cooperative Agreement No 00-shy‐FG-shy‐34-shy‐ 0009 p 32 ArizonaGame and Fish Department Phoenix

Marsh13 P13 C13 1987a13 Digestive tract13 contents13 of adult razorback suckers13 in Lake13 MohaveArizona-shy‐Nevada Transactions of the American Fisheries Society 116117-shy‐119

Marsh P C 1987b Native fishes at Buenos Aires National Wildlife Refuge and ArizonaState University Research Park Arizona opportunities for management researchand public13 education13 on13 endangered species13 Proceedings of the Desert13 FishesCouncil 1967-shy‐78

Marsh P C 1994 Rearing native Colorado River fishes in golf course ponds Arizona StateUniversity Tempe 22 + pages

Marsh13 P13 C13 200013 Fish population13 status and evaluation13 in13 the Cibola13 High Levee PondFinal report agreement number 99-shy‐FG-shy‐30-shy‐00051 US Bureau of ReclamationBoulder City13 Nevada13 20 pages

Marsh P C and C A Pacey 1998 Growth of wild adult razorback suckers13 in Lake13 Mohave13 Arizona-shy‐Nevada13 Final report13 US Bureau of Reclamation Boulder City Nevada 25pages + appendices

53

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Marsh P C B R Kesner and C A Pacey 2005 Repatriation as s management strategy13 to13 conserve a critically13 imperiled fish species North American Journal of FisheriesManagement 25 547-shy‐556

Marsh P C and C A Pacey 2005 Immiscibility of native and non-shy‐native13 fishes Pages 59-shy‐63 inMJ13 Brouder13 CL13 Springer13 and CS13 Leon13 editors13 Proceedings of two13 symposia Restoring native fish to the lower Colorado River interactions of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 NV and13 Restoring natural13 function within a modified riverine environment the lower Colorado River13 July13 8-shy‐913 1998 Las Vegas NV US Fish and13 Wildlife13 Service Southwest Region AlbuquerqueNew Mexico

Marsh13 P13 C13 and J13 E Brooks13 198913 Predation13 by ictalurid catfishes as a deterrent13 toreestablishment of hatchery-shy‐reared13 razorback sucker The Southwestern Naturalist34188-shy‐195

Matthews R A 2005 Ichthyopthirus multifiliis Fouquet and Ichthyopthirosis infreshwater13 teleosts13 Pages13 159-shy‐218 in Advances in Parasitology volume 59 J RBaker R Muller D Rollinson (eds) Academic Press

McCarthy13 M S and W L Minckley 1987 Age estimation for razorback sucker (PiscesCatostomidae) from13 Lake Mohave Arizona and Nevada Journal of the Arizona-shy‐Nevada Academy of Science 2187-shy‐97

Minckley13 W L13 198313 Status of the razorback13 sucker13 Xyrauchen texanus (Abbot)13 in13 thelower Colorado River basin13 The Southwestern13 Naturalist13 28(2) 165-shy‐187

Minckley13 W L13 199113 Native fished of the Grand Canyon13 region an obituary13 Pages 124-shy‐177 in Colorado River ecology and dam13 management National Academy PressWashington13 DC

Minckley13 C13 O and M LaBarbara13 199913 Report13 on13 native fish grow-shy‐out facilities13 at Cibolaand Imperial National Wildlife Refuges 1993-shy‐199513 US Fish and13 Wildlife Service13 Parker Fishery Resources Office Parker Arizona

Modde13 T13 199613 Juvenile razorback sucker (Xyrauchen texanus) in a managed wetlandadjacent13 to the Green13 River13 Great13 Basin13 Naturalist13 56375-shy‐376

Modde T KP Burnham and E J Wick 1996 Population status of the razorback sucker13 inthe middle Green River (USA) Conservation13 biology 10 110-shy‐119

Modde13 T13 and G13 B Haines13 200513 Survival13 and growth of stocked razorback13 sucker andbonytail in multiple floodplain wetlands of the middle Green River under resetconditions13 Final report prepared for Upper Colorado13 River13 Basin RecoveryImplimentation Program US Fish and Wildlife Service Vernal 66 pp

54

13

Modde T Z H Bowen and D C Kitcheyan 2005 Spatial and temporal use of a spawning13 site in the middle Green River by wild hatchery-shy‐reared13 razorback suckers13 Transactions of the American Fisheries Society 134937-shy‐944

Mueller13 G13 199213 The native fish work13 group13 -shy‐ a multiagency endeavor to improve thestatus of the razorback sucker in Lake Mohave AZ-shy‐NV13 Proceedings of the DesertFishes Council 2369

Mueller G 1995 A program13 for maintaining the razorback sucker in Lake MohaveAmerican Fisheries Society Symposium 15127-shy‐135

Mueller13 G13 200613 Ecology of the bonytail13 and razorback13 sucker and the role of offchannelhabitats13 in their13 recovery Scientific13 investigations13 report 2006-shy‐5065 US GeologicalSurvey13 Denver

Mueller G and E Wick 1998 Testing of golf course ponds at Page Arizona for suitability13 as grow-shy‐out facility for razorback sucker using surplus fish from13 Ouray NationalFish Hatchery National Park Service US Fish and13 Wildlife13 Service and UtahDivision of Wildlife13 Resources 28 pages

Mueller13 G13 and T13 Burke13 200513 Survival13 of young13 razorback13 sucker (Xyrauchen texanus) inrelation to13 stocking rates13 (fishha)13 and13 in the presence13 or absence13 of predatorcommunities in Lake Mohave Arizona-shy‐Nevada13 Pages13 155-shy‐16313 in Proceedings of two13 symposia restoring native fish to the lower Colorado River interaction13 of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 Nevada US Fish and Wildlife13 Service Southwest Region Albuquerque New Mexico

Mueller13 G13 J13 Carpenter13 and P13 C13 Marsh13 200413 Cibola13 High Levee Pond annual report 2004US Geological Survey Fort Collins13 Science Center13 Colorado13 and Arizona StateUniversity Tempe 23 pages

Nesler T P K Christopherson J M Hudson C W McAda F Pfeifer and T E Czapla 2003An integrated stocking plan for razorback sucker bonytail and Colorado13 pikeminnow for the Upper Colorado River Endangered Fish Recovery ProgramAddendum13 to State Stocking Plans Upper Colorado River Basin Recovery13 Implementation Program 12 pp

Papoulias13 D and W13 L Minckley13 1992 Effects13 of foo availability13 on survival and growth13 of larval razorback suckers13 in ponds Transactions of the American Fisheries Society121340-shy‐355

Paukert13 C P D L Ward13 P J Sponholtz13 and K13 D Hilwig13 Effects13 of repeated hoopnetting13 on bonytail chub13 Journal of Freshwater13 Ecology13 20(4) 649-shy‐653

Pfeifer F M13 C Baker13 and M13 Montagne13 199913 Propagation13 facilities13 in the13 Grand Valley13 (24 Road13 Hatchery13 Horsethief13 Ponds and13 grow-shy‐out ponds) for captive rearing of

55

13

endangered13 fishes for the13 Upper Colorado13 River Basin13 Colorado13 River Recovery13 Program FY 99 annual project report Project No 29a13 US Fish and Wildlife Service13 Grand13 Junction13 5pp

Pfeifer F S Seversen and M Montagne 2003 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2003 annual reportProject No 29b13 US Fish and Wildlife13 Service Vernal13 4pp

Rabago-shy‐Castro J L Sanchez13 J G Perez-shy‐Castaneda R and13 Gonzalez-shy‐Gonzlez A 2006Effects of the prophylactic use of Romet-shy‐3013 and13 copper13 sulfate13 on growth13 condition13 and feeding13 indicies in13 channel13 catfish (Ictalurus punctatus) Aquaculture 253 343-shy‐349

Reinitz GL L E Orme and F N Hitzel 1979 Variations of body compositio and growth13 among strains of rainbow trout Transactions of the American Fisheries Society 108204-shy‐207

Ruppert13 J13 B P B Holden13 and P D Abate 1999 Age estimation and growth of razorbacksucker13 Xyrauchen texanus in Lake13 Mead Nevada Proceedings13 of the Desert FishesCouncil 3040

Schnoor K D and J Logan 2002 Operation and maintenance of JW Mumma nativeaquatic13 species restoration facility Colorado Colorado River Recovery Program FY2002 annual project report13 Project No 29d Colorado13 Division of Wildlife Alamosa3pp

Salisbury13 L13 1998 Factors13 affecting razorback13 sucker growth13 in Lake13 Mohave backwaters13 MS Thesis13 Unviersity13 of Nevada13 Las13 Vegas

Schooley J13 D13 and P C13 Marsh13 2007 Stocking of endangerdd13 razorback13 suckers13 in thelower Colorado River Basin13 over three decades 1974-shy‐2004 North American Journalof Fisheries Management 27 43-shy‐51

Severson S H H M Tyus and G B Haines 1992 An evaluation of feeds for raisingrazorback sucker Xyrauchen texanus Journal of Applied Aquaculture 155-shy‐65

Toney D P 1974 Observations13 on the13 propagation13 and13 rearing13 of two13 endangered species13 in a hatchery environment Proceedings of the Annual Conference of the Western13 Association of State Game and Fish Commissions 54 252-shy‐259

Tyus H M13 1998 Razorback sucker13 (Xyrauchen texanus) recovery plan13 University13 ofColorado Center for Limnology Boulder13 76 pages

Tyus H M13 and13 S H Severson 1990 Growth13 and13 survival of larval razorback suckers fedfive formulated diets The Progressive Fish Culturist 52197-shy‐200

56

13

Ulibarri M E 2003 Annual report fiscal year 2001 Dexter National Fish Hatchery13 andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 26 pages

Ulibarri M E 2003 Annual report fiscal year 2002 Dexter National Fish Hatchery andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 59 pages

USBR 2006 Lower13 Colorado13 River Multi-shy‐Species Conservation Program final fishaugmentation plan Boulder City 19 pp

USFWS 2002 Razorback sucker (Xyraouchen texanus) recovery goals Amendment andsupplement to the Razorback Sucker Recovery Plan13 US Fish and Wildlife Service13 Region 6 Denver13 Colorado

USFWS 1999 Annual report 1999 Ouray National Fish Hatchery Vernal 25pp

USFWS 2004 Management plan for the big-shy‐river13 fishes of the13 lower13 Colorado13 river basinamendment and supplement to the bonytail humpback chub Coloradopikeminnow and razorback sucker recovery plans

USFWS13 2005 Station13 profile13 of the13 Dexter13 National Fish Hatchery13 and Technology CenterUS Fish and Wildlife13 Service Dexter

Valdez R A P G Mangan R Smith and B Nilson 1982 Upper Colorado River fisheriesinvestigations13 inW H Miller J J Valentine D L Archer H M Tyus R A Valdezand L13 Kaeding13 editors13 Colorado River Fishery13 Project13 Part 2 Field13 investigations13 US Bureau of Reclamation Salt Lake City Utah

WBNFH 2004 Culture methods of the endangered razorback sucker Xyrauchen texanusUS Fish and Wildlife13 Service Willow Beach National Fish Hatchery13 8 pp

Ward D 2008 Effects of disease treatments on growth of razorback sucker ReportSubmitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 Inpartial fulfillment of work task C10 agreement number 06FG30039

Ward13 D13 M Childs and W Persons 2007 Factors13 affecting13 growth13 of razorback sucker13 (Xyrauchen texanus) in captivity Literature review and knowledge assessmentReport Submitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 In partial fulfillment of work task C10 agreement number 06FG30039

57

Appendices

Appendix 1 Survey Questions Survey of Razorback Sucker Culture in the

Southwestern United States

The enclosed survey is being distributed by the Arizona Game and Fish Department to razorback sucker culture facilities throughout

the Southwestern United States The purpose of this survey is to consolidate information regarding culture of this species so that

appropriate facility improvements can be considered for Bubbling Ponds Hatchery in Arizona Specifically we wish to increase

growth rate and production efficiency at the hatchery Information gathered in this survey will be summarized in a final report to US

Bureau of Reclamation in Boulder City NV and disseminated to all facilities that participate in the survey A workshop to discuss

the findings of this study as well as to share general information concerning razorback sucker culture will be organized by the

Arizona Game and Fish Department at the conclusion of this study and all participants will be invited

Thank you for taking the time to fill out this survey Please contact Mike Childs if you have questions or would like to discuss the

survey

Mike Childs

mchildssedonanet

(928) 639-1346

(928) 634-1279

Facility_____________________________________ Date___________________

Contact Phone _____________________________

ContactPerson_______________________________

Contact Email _______________________________

1 Water quality ranges at this culture facility

Season

Spring (Mar-May) Summer (Jun-Aug) Fall (Sept-Nov) Winter (Dec-Feb)

Temperature (C)

PH

DO (mgL)

PO4 (mgL)

TDS (mgL)

Hardness (mgL)

CaCO3

Pathogens

37

13

Growth in Lined Ponds 43Growth in unlined ponds 43

CONC

Eff

L

e

US

cts

A

EffectIONS

of sorting on growth 44

LITER

CKN

A

OW

of

D

I

G

ch

TU

LE

RE13 C

E

I

M

o

E

n

N

r

T

a

S

z

orbacksucker growth rates

TED

51

504747

AP

AAPPPEEN

NDDICIXE12

SSFURVEY Q

-shy‐UESSTIONS

APPENDIX

3 TOLLOW UP URVE

YS

5858

PPENDIX ABULATED13 SURVEY RESULTS

6162

Li

Ta

st

Tableble13 1

of T

List

ab

of

les13

2 Facilitiesloca

and

tion

F

s13

i

availablet

gu

hat

res

athamajorve13 been

razorbackused13 to13 grow-shy‐out razorback suckers11

TaTabblle13 3e13 4

WStockater13 qua

ing13 densitlity13 ra

ies13 fornges13 a

ltarvaeach13 cul

e13 and13 fryture13 fa

sucker fish hatcheries12

Table13 5 Rearing13 densities13 at intincil

ensive13 culture13 fapondsity

cilities19

13

19

TaTab

blle13 6e13 7

ReaTypes

ring13 praof feed

ctices13 tused

haattraare13 unique

Table 8 Factors limiting productionzorback suck

to13 specificer13 hatcheries

rearing13 facilities

2020

Table 9 Reported and calculated growthat major

ratesrazorbackfrom13 the literature

sucker facilities

2021

FigureFigure13

12 PhotoRelationship between length and number of fish per pound18

FigFiguure13 re13 34EPhotffect

o13 ofof disease treatment experimental setup31

Figure13 5 Temperatureofdiselined13

ase treatments on razorback

ofanpondd13 unl

8inuppered13 pon

inds200

growth

9

rates

3338

FigFiguure13 re13 6713 13 RazTemperature

orof ponds 7 and 8 upper in 2009-shy‐201042

40

FigFiguure13 re13 9813 Raz13 Razor

or

back13 grback13 gr

owth13 rowth13 in

atesan unlined

in lined13 pondspond

4544

FigFiguure13 re13 101113 13 EffectEffect13 of

back13 grsor

owting13 onth in13 li

razneordback13 grvs13 unli

of Ich on razorbowthned ponds

45

ack growth13 rates4646

4

13

Executive13 SummaryThe few remaining razorback sucker populations are sustained by captive13 rearing13

and stocking programs and the survival13 of stocked suckers in13 the wild is largely13 associated

with size at stocking Experimental studies at Bubbling Ponds Fish Hatchery AZ have been

ongoing for the13 last 5 years13 to13 understand13 factors13 that affect razorback sucker13 growth13 in

captivity13 and to13 identify ways to improve growth rates and maximize size at release This

work13 consists of a literature review an experimental study of disease treatment effects13

and observations of individual13 fish growth in13 ponds under different13 conditions

Literature13 review

A literature review and hatchery13 site visits concluded that13 razorback13 sucker growth

is extremely variable and impacted by many factors including fish size and age sex density

amount of living space quality and quantity of food genetics and temperature13 Culture13

practices for razorback13 suckers vary13 widely13 and include13 differences in rearing13

environments rearing densities feeding regimes and types of feed as well as grading or

sorting practices Calculated growth rates from13 the literature vary widely and range from13

02 ndash 18 mmday with the highest growth rates reported from13 natural or semi-shy‐natural13

pond environments These growth rates indicate that juvenile razorback suckers have a

very hig growth13 potential under ideal rearing conditions13

Growth during disease13 treatments

Formalin copper sulfate potassium13 permanganate and salt are all chemicals

commonly used to treat Ichthyophthirius multifiliis and other disease outbreaks13 in hatchery13

populations of razorback13 sucker13 We exposed juvenile razorback13 suckers to 513 5-shy‐day13

treatments with each chemical to evaluate the effects these chemicals may have on growth

Fish grew an average of 235 mm TL during the 3 month study period No significant

differences in growth were observed among fish treated with any of the chemicals

compared to untreated fish (pgt005) Reductions in growth as a result of repeated chemical

treatments are not likely the cause of differences in growth rates among facilities that raise

razorback suckers Repeated chemical treatments may have other impacts to overall

fitness13 or long-shy‐term13 survival but these effects were not evident in our study

5

13

Pond growth studies

Growth13 studies13 were13 conducted13 at the13 Bubbling Ponds Fish Hatchery from13 2009 to

2011 These studies13 were13 largely13 observational13 because hatchery production requirements

prevented experimental manipulation of dependent variables Our initial13 work13 identified

razorback growth rates in lined ponds at standard fish density as 026 to 028mmday

(789 to 843 mmmonth) Additional13 studies include observations of growth rates in13 lined

and unlined ponds13 fish at different13 densities13 sorting13 practices13 and growth in13 the absence

of the13 ectoparasite13 Ich

Our data13 suggests that13 growth rates at the Bubbling13 Ponds Fish Hatchery are likely

as high as possible given the pond densities required to meet production goals and the Ich-shy‐

infested water that feeds the facility Sorting practices are successful in helping as many

fish as13 possible13 reach13 stocking13 length13 as13 fast as13 possible13 Unlined13 ponds may be able to

grow13 large13 fish at low densities but whatever factors13 allow for that growth13 are13 not able to

overcome high fish density Growth rates were highest following removal of Ich from13 the

Bubbling13 Ponds Spring13 032 mmday (96 mmmonth) but that growth13 rate13 decreased13

again13 as Ich re-shy‐infested13 the13 hatchery

Conclusions

We conclude that under typical hatchery operations (maximizing number of fish

produced)13 the growth13 rate13 of razorback13 suckers is relatively13 consistent at Bubbling13 Ponds

hatchery13 at13 02-shy‐03 mmday (6-shy‐9 mmmonth)13 but is lower than growth13 rates13 at other

facilities (02 ndash 18 mmday Ward et al 2007)13 This growth13 rate13 has13 been13 constant in both13

lined and unlined ponds at all fish densities we were able to measure is temperature

independent13 and13 is likely13 enhanced13 by13 separating13 fast and13 slow-shy‐growing13 fish after the first13

year of growth13 To achieve13 growth13 rates13 substantially13 higher than13 this13 will likely13 require

significant changes in rearing practices that may not be practical in order to13 reach13

numerical production13 goals

Two major changes that might result in higher growth rates are substantially

reducing fish density and modifying the way spring water is delivered to the facility (via

either repeated chemical treatments or enclosed concrete water diversions) to eliminate

Ich from13 the hatchery source water Other potential changes not address by our work

6

13

include13 flow-shy‐training razorbacks much previous literature including MSCP-shy‐funded13 work

on razorback suckers13 suggests13 that fish growing13 in flowing13 water13 will grow faster13 than13 fish

in still water (Jorgensen and Jobling 1994) Furthermore there are a wide variety13 of

potential benefits associated with growing13 fish13 in flowing13 water in addition13 to increased

growth13 rates13 (Davidson13 1997 Castro13 et al 2011)13 Finally given that stocking of smaller

razorbacks13 has13 been13 largely unsuccessful13 perhaps13 BPH goals could be changed from13

producing 12000 fish at 300+ mm per year to a smaller number of very large fish each

year Growing fewer larger fish could potentially be accomplished in the same time frame

as more smaller fish but a better understanding13 of how13 density alters growth rate would

be required to be confident13 of this

7

13

I Literature13 Review

Section13 SummaryThe few remaining razorback sucker populations are sustained by captive rearing and stockingprograms Captive-shy‐reared razorback suckers commonly13 experience13 high predation whenstocked into natural environments This13 creates13 the need to rear fish to larger sizes13 in captivityand to13 find new ways to13 improve growth for captive-shy‐reared fish We reviewed publishedliterature and agency reports for information on factors that affect growth of13 razorback suckerSite visits to13 razorback sucker production facilities and surveys of fish hatchery13 personnel wereconducted to obtain information on current rearing practices Razorback sucker growth is13 extremely13 variable13 and impacted by13 many13 factors including13 fish size13 and age sex densityamount of living13 space quality13 and quantity13 of food genetics and temperature This makesevaluations of individual factors that affect growth difficult Culture13 practices for razorbacksuckers13 vary widely and include differences13 in rearing environments rearing densities feedingregimes and types of feed as well as grading or13 sorting practices The focus at most razorbackrearing facilities is production so the types of data that are collected13 are often insufficient fordetailed13 evaluations of rearing practices on growth Calculated13 growth13 rates from theliterature vary widely and range from 02 ndash 1813 mmday Typically the highest growth13 rates arereported from natural or semi-shy‐natural pond environments These growth rates indicate thatjuvenile razorback suckers have a very high growth potential under ideal rearing conditionsDetailed replicated studies are needed to accurately compare the effects of individual rearingpractices on13 growth These types of studies will ultimately provide both time and cost-shy‐savings13 to production facilities by reducing the time it13 takes for razorback suckers to reach stockingsize improving overall production efficiency

8

13

Introduction

State and federal wildlife management agencies have been rearing razorback

suckers in captivity since the 1970rsquos (Toney 1974 Hamman 1985) to augment declining

natural13 populations Both wild-shy‐caught larvae13 and captive-shy‐bred fish are reared at fish

hatcheries13 and13 grow-shy‐out ponds throughout the13 southwestern13 United13 States13 (reviewed13 in

Mueller 2006) Each facility has unique environmental conditions and different rearing

methods which yield different growth rates Unlike commercial fish species which have

been cultured and studied extensively little published information is available on the

effects of various rearing methods on growth of razorback sucker

Low survival rates13 of stocked13 razorback suckers13 (Brooks13 1986 Marsh13 and13 Brooks13

1989 Marsh13 and13 Pacey13 2005)13 have13 caused13 target sizes for stocking13 to13 steadily13 increase13 in

efforts to reduce predation mortality (Marsh et al 2005 Schooley and Marsh 2007)

Rearing fish to larger sizes comes with increased costs and creates the need to know which

factors13 have the greatest impact on growth rate and how these factors can be controlled to

maximize growth This document compiles and summarizes information on current

captive13 rearing practices13 and associated13 growth13 rates13 for razorback sucker13

We reviewed relevant13 published literature and agency reports on13 razorback13 sucker

to compile background information regarding the effects of environmental factors and

rearing methods on growth A questionnaire was developed (Appendix 1) and sent to

hatchery managers who rear razorback suckers Follow up surveys13 were13 also13 conducted13

by telephone (Appendix 2) Information on rearing densities water quality diseases and

management practices at each facility were recorded Site visits to Bubbling Ponds State

Fish Hatchery13 in Arizona Dexter National Fish Hatchery in New Mexico Grand Valley

Endangered Fish13 Facility13 in Colorado13 Ouray13 National13 Fish13 Hatchery13 in Utah and the Willow

Beach National Fish Hatchery in Arizona were also conducted as part of this knowledge

assessment Telephone interviews were conducted with personnel from13 other locations

that13 produce razorback13 suckers (Uvalde National13 Fish Hatchery13 Hualapai Ponds13 Lake

Mead Fish Hatchery and JW Mumma Fish Hatchery) or facilities that formerly produced

razorback suckers but currently focus on other species (Wahweap Fish Hatchery Achii

Hanyo13 National Fish Hatchery Mora National Fish Hatchery)

9

13

Information from13 all of these sources is summarized to aid future researchers in the

design of more detailed studies on razorback sucker13 growth Understanding the13 factors13

that13 control13 razorback13 sucker growth will13 allow13 expanded fish-shy‐rearing capabilities13 and13 aid13

in reaching management objectives for stocked fish Preservation of genetic resources for

razorback suckers13 depends on captive rearing and stocking programs until permanent

solutions to factors that prevent wild recruitment can be found

Summary13 of Facilities

There are13 over 50 locations13 that have13 been13 used to13 rear13 razorback suckers13 (Table13 1) These

include13 both13 intensive13 culture13 facilities13 with13 raceways13 or circular13 tanks13 as13 well as13

production13 ponds13 golf-shy‐course13 ponds and natural floodplain-shy‐wetlands The majority of

razorback suckers that are stocked come from13 six major production facilities Bubbling

Ponds State13 Fish13 Hatchery13 The Grand13 Valley13 Endangered13 Fish Facility13 and13 Dexter13 Ouray13

Willow13 Beach13 and Uvalde National13 Fish Hatcheries13 Tables 2-shy‐313 outline13 the13 types13 of fish

holding facilities and water quality conditions that exist at each of these main production

locations A brief summary of procedures for rearing razorback suckers at each of these

facilities13 follows

These summaries are based on interviews conducted with hatchery personnel in July 2007 during site visits

This information13 is provided only to give a brief overview of razorback grow-shy‐out procedures Please verify13

accuracy13 of specific information with individual hatchery managers

10

13

Table13 1 List of locations13 that have13 been13 used to13 grow-shy‐out razorback suckers

$$amp ()amp$+ ($ampamp$+( $amp()$+ $amp()amp+(-0(12(342056( )0(-75amp8(95amp( 0$$05(lt==gt( 5amp+(amp4amp(Aamp+amp050+(12(14$6( 5amp+(amp4amp8(B$5+( B7$(lt==lt8()C0C05(lt===8(D0$05(0($(lt==E8(amp2F(0($(lt==E(

GltHI5+(342056J( K0L05(Damp$(12(342056( K0L058(D0M(0L4( N$055(lt==E( FF(-0(12(342056( D05(9$F8(B$5+( -42amp5(amp+($amp(lt==lt( OP0(0+(342056( $+05(B68(D0Q+( N-R(lt==gt( S56(Damp$(12(342056( D05(T05amp$8(N2( B7$(lt==lt8(U5Qamp(0($(lt==H8()C0C05(0($(lt==E8(0$$05(lt==gt8(N-1V-(WXXX( NQ$+0(Damp$(12(342056( NQ$+08(Y0L( N-R(lt==gt( V2M07(12(342056( M058(N2( B7$(lt==lt8(Qamp(amp+(5+M42(lt===( V$$M(042(Damp$(12(342056( 0$M(3Q05(KF(amp(B$5+(RQ058(95amp( 3ampamp(WXXgt( 942(3amp6( D05()5P058(95amp( N-1V-(lt==Z( --+-0+-12-3(4-5 )005(7amp+( 5amp+(amp4amp8(B$5+( Y2+(amp2F8(705amp$(4FFamp4amp( ltgt(5+(7amp+( 5amp+(amp4amp8(B$5+( )C0C05(0($[(WXXX( amp+(7amp+(( 5amp+(amp4amp8(B$5+( )C0C05(0($[(WXXX( B$6F05()amp+( BampC$0amp40(C(B$5+(amp+(ampampamp( )C0C05(0($[(WXXX8(B7$(lt==lt( B$5+(I(W](++amp$($00+(7amp+( 5amp+(T$$068(B$5+( )C0C05(lt===( KP0(5+(7amp+( 5amp+(T$$068(B$5+( )C0C05(0($[(WXXX( 32$amp0(7amp+( 5amp+(T$$068(B$5+( )C0C05(0($[(WXXX( 35020C(505amp(7amp+( 5amp+(amp4amp8(B$5+( )C0C05(lt===8(B7$(lt==lt( 0-6-3+ $620(Famp47$($C(450( $6208(B$C5amp( ^50amp($C(450_(9-N(R00542()5P( 08(95amp( 52(WXXH8(52(WX]( )0($C(450(7amp+( )08(95amp( 0$$05(amp+(V4P(WXX]( 768639 0amp(50(DVR( -2(C(Y4amp8(95amp( 52(WX]( B$(32(O0Q00()amp+( B$(Damp$(V$+$C0(R0C08(D05($6208(B$C5amp( 52(lt===8(amp4P$06(amp+(O55(WXXX8(0$$05(lt==gt( SQ05amp(M$+$C0(amp0F0amp(50( D05(OP0(0+(ampC$M8(D0Q+( N-R(lt==gt( -0amp5(V2( D52(C(`F8(95amp( ^5042Fampamp(amp+(O0$0(lt==gt8(amp4P$06(amp+(O55(WXXX( )1(+ KQ(4Q0( OP0(2Q08(95amp( 0$$05(WXXlt8(0$$05(amp+(5P0(lt==Z( 95amp(aQ0amp$0( OP0(2Q08(95amp( -$56(WXX]( -2(-+0Mamp+05( OP0(2Q08(95amp( -$56(WXX]( `F(BQ0( OP0(2Q08(95amp( 0$$05(WXXlt8(0$$05(amp+(5P0(lt==Z( Kamp+6( OP0(2Q08(D0Q+( -$56(WXX]( D52(B20F020Q0( OP0(2Q08(D0Q+( -$56(WXX]( D52(X($0( OP0(2Q08(D0Q+( Y6(V$05(N-R8(705amp$(4FFamp4amp( V$$M( OP0(2Q08(D0Q+( Y6(V$05(N-R8(705amp$(4FFamp4amp( D0Q+(A( OP0(2Q08(D0Q+( Y6(V$05(N-R8(705amp$(4FFamp4amp( D0Q+(O5Q0( OP0(2Q08(D0Q+( Y6(V$05(N-R8(705amp$(4FFamp4amp( 0+58lt+--457(5 9Q0(50ampampamp( D05(T05amp$8(N2( )C0C05(0($[(lt==E( ampamp(5+0( D05(T05amp$8(N2( )C0C05(0($[(lt==E( 2ampamp(F( D05(T05amp$8(N2( ++0(amp+(3amp0(lt==Z( O0(W=( D05(T05amp$8(N2( N-1V-(WXXX( O0(F( D05(T05amp$8(N2( ++0(amp+(3amp0(lt==Z( S$+(425$06(V2( D05(T05amp$8(N2( ++0(amp+(3amp0(lt==Z8(++0(WXXgt( O00+(7amp+(amp(20(Namp2(amp( D05(T05amp$8(N2( U5Qamp(0($(lt==H8()C0C05(0($(lt==E( =($+ 1$6+(OF(0(75P(GY0$0(75ampJ( O(T08(D0Q+ (52(WXXH( Y5amp++(-0(amp5(B$$00( 9$F8(B$5+( -42amp5(amp+(Oamp(lt==lt( 5MI(7amp+( D05(15Fampamp8(D( -42amp5(amp+(Oamp(lt==lt(

11

13

Table 2 Facilities available at major razorback sucker fish hatcheries

$amp( )$+(-+( 0(1(2$amp3amp(( 4-56+ amp7(8-+1$(9+( lt3-5( 8=$33( 23gt(805(

$amp()amp+(-(012345( 0(0+amp(A(BBCC(05 ampD(ED F CGBH IACCCACCC BJH K$+L(0D

amp$+(M$gt$ O-$+(+($P

B N B

CGBH IACCCACCC BABHC FANCC

BJH

Qamp+-3$+($P F FHC 637134(801amp0$(-(012345( H(L$33gt($O-amp1+(gt33A(

BCCC(05 ampDRK$+L(0D amp$+(M$gt$ M$-3$+($P Qamp+-3$+($P Qamp+-3$+($P

9O-$+amp$

SF S BC SC HC TC

CGI((IGC( HAHCC HSC IBC BCC IC

9O-$+amp$ BC SC 940amp+(amp21amp(8013(-(-02$15( U-ampamp0$3(D+ampPamp(gt$+ Qamp+-3$+($P IS VCC IB

W+Lamp1(+$+amp(0D( E-50D(+ampX+(gt$+( Qamp+-3$+($P JT BCC H K$+L(ED T CGBH(Y(CGH(

lt405(801amp0$(-(012345( J(L$33gt(gt33A(FCC(05( ampD(0D BS CGIBH(Z(CGBH( IC Qamp+-3$+($P NC IBC H Qamp+-3$+($P BJ VCC IC((IH

=$$gt(302(801amp0$(-(012345( 3$+(L$D(Q3+$D( MampX+(gt$+( amp$+(M$gt$ N IAHCC

amp$+(M$gt$ IF IFACCC 9O-$+amp$ FC IC

0$+3(801amp0$(-(012345( B([0(9O-amp1+()33A( IHCC(05 ampD(0D II I

K$+L(0D amp$+(M$gt$ amp$+(M$gt$

NJ B IB

GBH(Y(IGC( FAHCC IACCC

Qamp+-3$+($P Qamp+-3$+($P

IB N

BCC NACCC

12

13

Table13 3 Water13 quality13 ranges13 at each13 culture facility$amp ($)$++) -+$

-)amp012$)32$45 -6+)01763865 9$01-+3lt5 =amp+)01gt+39+5 $amp()amp+ ++)$6)+01A5

J gtLNL01O5 8P$ampamp401O5 ($Q+

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8+)$O(6+T$ 8+)$ 8+)$ A6$)amp A6$)amp A6$)amp

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RQS0Aamp$ )ampQTamp$ 8+)$ A6$)amp

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BK3DE DD3DM BK3DE KLC3MLC KLC MLC DLM3GLK DLM3GLK DLM3GLK BIC3BMM BIC3BMM BIC3BMM

2ampamp$03040UQ$0amp0)6Q0amp0UampQ0ampamp0VampQ

BE3BI KLC

DLM3GLK BIC3BMM

213amp+(4amp50amp ++)$6)+01A5 J gtLNL01O5 8P$ampamp401O5 ($Q+

DH3DC DH3DC DH3DC KLK3MLE KLK3MLE KLK3MLE KLE3KLC ILC3KLE ILE3ILC BEE BEE BEE

+0$0amp+amplt+066)+0V$ampamp4S0RQ0$0)TP0T

DH3DC KLK3MLE FLC3ILC BEE

6137 ++)$6)+01A5 J gtLNL01O5 8P$ampamp401O5 ($Q+

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BB3DC KLF3MLD CLE3KLD BBG Aamp$

8$$9(35 ++)$6)+01A5 J gtLNL01O5 8P$ampamp401O5 ($Q+

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BH3BM KLC3MLE FLE3GLE HEE3FEE RQS0Aamp$ A6$)amp 8+)$

lt3$+ ++)$6)+01A5 J gtLNL01O5 8P$ampamp401O5 ($Q+

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A6$)amp

BF3BM KLK3MLD FLE3BDLE DDI

Bubbling Ponds State13 fish Hatchery13

Bubbling Ponds Fish Hatchery in Arizona does not maintain razorback sucker

broodstock on site Razorback suckers are received either as juveniles from13 Willow Beach

National Fish Hatchery13 or as13 newly-shy‐hatched larvae from13 Dexter13 National Fish Hatchery

Larval fish are13 typically13 placed13 into13 an unfertilized unlined 0613 acre13 pond13 in the13 spring In

September the pond is harvested by draining the pond and seining All fish that have

reached the target size (300 mm TL) are stocked Fish that are too small to stock are split

up equally between the six remaining grow-shy‐out pond at an13 average13 density13 of about 5000

ndash 7000 fish per pond Fish are fed by hand at approximately 25 body weight split

between morning and evening feedings Fish are either fed a catfish diet made by Rangenreg

13

13

that is enriched with spirulina and krill or razorback sucker diet made by Silvercupreg

depending on availability Fish are monitored visually and by sampling using a cast net

When a large number13 of fish have13 grown to13 the13 target size they13 are13 harvested13 by13 draining

the pond and seining13 Fish are again13 sorted by hand and the largest13 fish are stocked13 Fish

that13 have not13 reached the target13 size are returned to the ponds for further grow-shy‐out13 On13

average it13 takes one to two years for fish to reach the target13 size with fish growing13 an

average of 06 mmday Target numbers for production are 12000 razorback suckers

annually (300 mm TL) The biggest difficulty in rearing razorback suckers at Bubbling

Ponds13 Fish Hatchery13 is protozoan13 parasite13 infestations13 (Ich) and13 associated13 bacterial

infections that come from13 an open spring source that is inhabited by mosquitofish

Dexter National Fish Hatchery13

Dexter National Fish Hatchery maintains four separate razorback sucker13

broodstocks13 These fish are spawned on13 site and larval13 fish are placed directly into 01 acre

ponds at a density13 of about 20000 larvae13 per pond (50 ndash 100 thousand13 per13 acre)13 Ponds

are fertilized with alfalfa13 pellets and superphosphate two weeks prior to receiving13 larvae to

produce13 natural13 feed for larval13 fish13 Ponds are13 fertilized again with alfalfa13 pellets one week

after larvae are introduced13 Fish are fed a catfish starter diet13 (sizes 1-shy‐3) made by Rangenreg

that13 is enhanced with spirulina13 and krill13 and then switched over to the razorback13 diet13 once

they are large enough to eat 1mm13 crumble Fish are fed twice a day by hand four days a

week13 at 25-shy‐60 body weight Feed ration is decreased if excess feed is seen remaining

on the13 pond bottom13 following feedings Fish are not graded or sorted during this grow-shy‐out

period Razorback suckers are harvested in the fall by draining ponds completely Fish are

sorted13 at harvest and13 distributed13 to13 other13 facilities13 for further13 grow-shy‐out depending on13

current size requirements Razorback suckers are on average 100 ndash 200 mm TL after the

first growing13 season13 and13 generally13 take13 1 -shy‐18 months for a majority of the fish to reach

300 mm TL There are 16 different species of fish maintained at Dexter National13 Fish13

Hatchery13 and13 having sufficient pond13 space13 to13 grow out separate13 groups13 of fish is the13

limiting factor for production of razorback suckers at this location

14

13

Grand Valley13 Native13 Fish Facility13

The Grand Valley Native Fish Facility maintains its own brood stock13 in13 eight13 ponds

located at the Horsethief Basin Wildlife Area in Grand Junction Colorado Fish are

spawned13 on site13 and13 larvae13 are13 reared13 indoors in fiberglass13 tanks13 at the13 24-shy‐Road13 Fish13

Hatchery13 in Grand13 Junction The 24-shy‐Road13 Hatchery13 consists of two13 separate13 recirculating13

systems that operate using de-shy‐chlorinated13 city13 water13 and two13 large13 fluidized-shy‐ bed sand

filters13 and13 rotating-shy‐drum13 filters for waste removal Fish are held in 4-shy‐foot (n=78) or 8-shy‐foot

(n=14) diameter fiberglass tanks Larval fish are started on prepared feeds immediately

after swim-shy‐up and fed exclusively razorback feeds made by Silvercupreg Fish are started on

a 0-shy‐250 micron razorback diet for the first 10-shy‐1213 days13 and13 then13 fed with13 gradually13

increasing13 feed sizes based13 on observations of feeding13 (250 ndash 400 micron 1 starter) Feed

sizes are mixed when transitioning to the next larger feed size These razorback diets are

specially sifted by Dr Rick Barrows (USDA13 Hagerman experiment station Idaho)

Razorbacks13 are13 typically eating 1mm13 extruded pellets by the time they are 35 to 4 inches

in length Fish are fed approximately 70 body weight per day initially and then gradually

reduced to 15 body weight by the time they reach the 300 mm TL target size Fish are

fed seven days13 a week using13 12-shy‐hr13 belt feeders It takes13 12-shy‐16 months to grow fish to the

target13 size in13 the hatchery13

Razorback suckers are sorted after three months and culled to about 4000 fish per

family lot Culled fish are stocked into leased grow-shy‐out ponds Stocking densities for

juveniles in these ponds is based on previous13 stocking and harvest13 rates13 and is pond

specific13 Grow-shy‐out ponds are13 harvested13 periodically13 using Fyke13 nets13 or trap13 nets13 and13 fish of

the target size are stocked Disease problems (Ich Lernea) water quality problems (low

DO) and difficulty in removing all of the fish are challenges for grow-shy‐out of razorback

suckers13 in these13 natural ponds13

Fish reared13 in the13 24-shy‐Road facility are sorted again at four to five months of age into

small and large size groups to obtain more uniform13 growth rates Batch estimates of fish

weight are done every month for each tank A group of fish are weighed and counted to

give an average weight for the tank with lengths estimated based on a lengthweight chart13

The biggest difficulties13 for growing13 out razorback suckers13 at the13 24-shy‐Road13 Fish13 Hatchery13 are13

insufficient space and water flow (oxygen) to grow fish to the target size At the Horsethief

15

13

Basin13 Ponds where broodstock13 are reared13 diseases such as Ich are problematic because

water is pumped directly from13 the Colorado River

Ouray13 National Fish Hatchery13

Ouray13 National13 Fish Hatchery maintains its own broodstock and13 spawns13 fish on-shy‐site13

Larvae are transferred from13 indoor hatching tanks to unfertilized 02 acre outdoor ponds

and stocked at densities 10000 ndash 20000 larvae13 per13 pond13 Even13 though13 outdoor13 ponds13 are13

covered with13 bird13 netting13 avian predators13 still get caught in the13 nets13 if they13 can see fish

Ponds are dyed blue13 as the13 fish grow to13 prevent avian predation13 While in the outdoor

ponds13 fish13 are13 fed a slow-shy‐sinking salmon diet made by Silvercupreg twice daily by hand

Amount of feed is based on periodic sample counts Fish are grown until late September at

which time temperatures require that all fish13 other13 than13 adult broodstock13 be13 brought

inside for the winter Ponds are drained completely and fish are sorted by hand Fish that

have reached the target size (300 mm TL) are stocked into the Green and Colorado Rivers

All remaining fish are moved indoors13 and13 held13 in three-shy‐foot (n= 30) or eight-shy‐foot (n=27)

diameter circular tanks On average it takes 12 ndash 18 months to grow fish to the 300 mm TL

at Ouray13 hatchery13

Razorback suckers are held during the winter in a recirculating system13 that

operates13 using13 two13 large13 fluidized-shy‐bed sand filters and a rotating-shy‐drum13 filter for solids

removal Fish are fed the Silvercupreg razorback diet using belt feeders There is currently

capacity13 to13 hold13 only13 20000 200-shy‐300 mm TL fish inside the facility and any extra fish13 are13

stocked13 into13 floodplain-shy‐wetlands or used for research purposes13 Ouray no longer leases

any private grow-shy‐out ponds Grow-shy‐out ponds were troublesome due to poor water quality

harvesting13 difficulties13 and13 non-shy‐native13 fish introductions13 The biggest difficulty13 for

production13 of razorback13 suckers at the Ouray13 National13 Fish13 Hatchery13 is space13 during13 the

winter to maintain large numbers of fish and high iron and manganese in the well water

that must be filtered out prior to use

16

13

Willow Beach National Fish Hatchery13

Willow13 Beach National13 Fish Hatchery receives wild-shy‐caught larvae from13 Lake

Mohave Larvae are treated for diseases with formalin and malachite green and placed in

45 ten-shy‐gallon13 flow-shy‐through aquaria13 Recirculated13 solar heated water13 22-shy‐25deg C is used to13

allow production of warm13 water fish at this traditionally cold water facility (Figiel 2003

Figiel et al 2005) Fish are fed brine shrimp nauplii to satiation every hour and after 14

days small amounts of specialized larval fish diet (Encapsulon13 Cyclopeeze13 spirulina13 and

artificial plankton) are introduced After 30-shy‐6013 days13 fish are13 transferred13 to13 six13 32-shy‐gallon13

fiberglass troughs at densities of 1000 to 1500 fish per tank and then a month later moved

outside13 to13 eight recirculating13 raceways that use a combination of well water and solar-shy‐

heated water to maintain temperatures of 22 ndash 25deg C during the summer months

When13 in13 the outside raceways13 fish are fed the razorback13 diet13 using13 belt13 feeders and

fed by13 hand13 at 10 -shy‐ 70 body13 weight per13 day Feed amount is adjusted based on sample

counts according to a feed conversion program13 developed for razorback suckers by Willow

Beach Hatchery personnel This program13 uses length and number-shy‐per-shy‐pound generated

from13 several years of razorback growth data (Figure13 1) Fish are13 sorted13 opportunistically13

and are not handled during the summer months when water temperatures are above 20degC

In 2004 the target size for stocking was 325 mm TL or greater (WBNFH 2004) with a

target13 of producing13 6000 fish per year Reaching this13 target size usually13 takes13 two13 growing13

seasons13 The biggest difficulty13 in rearing13 razorback suckers13 at Willow Beach13 National Fish

Hatchery13 is insufficient space13 to13 grow fish to13 increased13 target sizes (400-shy‐500 mm TL)

Uvalde13 National Fish Hatchery13

Uvalde13 National Fish Hatchery13 in Texas13 receives 35000 ndash 60000 razorback sucker13

fry annually in MarchApril from13 Dexter National Fish Hatchery The fry are acclimated in

bags submerged in the pond for a minimum13 of one hour and released into13 a 1 acre13 fertilized13

pond where they are reared for the remainder of the summer Fingerlings are fed a starter

razorback diet when they reach approximately 50 mm TL In AprilMay the previous year

class of razorbacks are captured from13 their over-shy‐wintering pond enumerated graded and

split into13 one-shy‐acre grow-shy‐out ponds Approximately 4000 ndash 5000 fish will be13 placed13 in each13

one acre pond for summer grow-shy‐out Fish are reared for approximately 150 days (May ndash

17

13

Oct) and fed the Bozeman razorback diet two times a day five days a week at 15 ndash 30

body weight per day based on average water temperature

Figure 1 Relationship between length and number of fish per pound

In general13 juvenile razorback13 suckers (received as fry13 during13 the previous spring)13

reach the target size of 300 mm TL in approximately 6 months In 20062007 Uvalde

produced 6000 razorback suckers 300 mm TL for introduction into the San Juan River

Starting13 in 2008 Uvalde NFH will be producing13 and distributing13 12000-shy‐ 300 mm TL

razorbacks for stocking into the San Juan River Predation from13 migrating cormorants has

occurred but timing of harvest and over wintering protection methods such as covering

ponds with netting or placing fish indoors helps to minimize losses during the cormorant

migration (November to March) Uvalde has experienced razorback mortalities because of

bacterial problems but these are usually resolved through the use of oxytetracyline

medicated feed

Overview13 of Differences in Culture Methods

Several differences were noted when conducting surveys at each of the five main

production facilities for razorback sucker (See Appendix 3) These differences include

different stocking13 and13 rearing13 densities13 (Table13 4-shy‐5) various feeding regimes and type of

18

13

lt=amp

feeds (Table 7) as well as differences in grading or sorting practices Some of these

differences are13 related13 to13 whether13 or not razorback suckers13 are13 being13 reared13 in extensive-shy‐

culture13 facilities13 (ponds) or intensive-shy‐culture13 settings13 (raceways13 o tanks)13 Some13 practices13

are unique to a single facility13 or a couple of facilities (Table 6)13 Managers at each facility13

were asked to identify the biggest13 difficulty or constraint13 that13 they experience when13

growing-shy‐out juvenile13 razorback suckers13 at their13 respective13 location13 Space constraints13

water quality and disease problems were the main factors limiting production of razorback

suckers13 at these13 facilities13 (Table13 8) Calculated or reported growth rates from13 the literature

vary widely (Table 9) and range from13 02 to 18 mmday These growth rates indicate that

juvenile razorback suckers have a very high growth potential under optimal rearing

conditions13

Table13 4 Stocking13 densities13 for larvae13 and13 fry in ponds

$amp( )(+amp-( 01-2(3(4amp56( 4amp56(+amp-( 01-2782-( $amp () + --amp +amp0amp)+amp 12-3amp ( )+amp0amp+amp --amp +amp0amp)+amp 42556789amp8 ( +amp0ampgt+amp 3amp +amp0amp+amp A-BC-Damp (E + 3amp )+ F-6ltamp ) G+ 3amp G+

Table13 5 Rearing13 densities13 at intensive13 culture13 facilities13

$amp( )amp+(($-( $0( 12(3$+( 40((amp05( 67((amp05( 8$9(407$( $amp amp())amp++-$amp 0 1 0amp2amp1amp 3amp2amp4 0544

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6amp())amp++-$amp 610 77amp2amp1amp 0amp2amp1amp 053

19

13

Table13 6 Rearing13 practices13 that are13 unique to13 specific rearing13 facilities13 $$amp( )$+-(amp$-(0(1-amp2034( $amp()amp+( -0$(12(33+(amp(amp134$53+(amp$amp3+(6amp+(

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Table13 7 Types of feed used at razorback sucker13 hatcheries13 $amp ()amp+-amp0- $$)1amp23 45-amp)-$5)1amp23 $amp()amp+( -amp$amp+(amp+( -amp012$3+(amp+4(amp5215$(0+( 65ampamp7(85209(+2($1(87((15315lt=(+2(

+amp+amp(amp(55$5$2gt( 21( Aamp+(amp+( )amp+(012$3+(B29(5$05$95($$2(5amp+(

199524(amp5215$(0+( 65ampamp7(85209(+2($1(87(15315lt=(+2(amplt( 29gt(51($51(amp9(2(25=(C(DD(0+(

E15amp+(Famplt2amp( G1$5(lt1lt$51(25amp=( HIJKH(Dlt1amp(15315lt=(+2(I(C2(CH(+5gt( )11$gt($511(02+(15315lt=(+2(

$1(87(15315lt=(+2(D5$$(3(lt5$$gt(02+(gt( 6lt=(511B(

L15gt( G1$5(lt1lt$51(25amp=(Aamp+( amp+(

HIJKH(Dlt1amp(15315lt=(+2(I(C2(CH(+5gt( )11$gt($511(02+(15315lt=(+2(

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M$$B(5lt9(-5$+( NO515(G1$5(219( L2+1(15ltB5gt(Aamp+(5amp+( amp$amp+(amp+(

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$1(87(15315lt=(+2($1(87(15315lt=(+2( $1(87(15315lt=(+2(

Table 8 Factors limiting production at major razorback sucker facilities

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20

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D(V1(

23=J

lt(6(

OBB

((

-(=22

Q(

L+amp-(B81(b

K5(gt

gtc((8D((KKK

(S ((

V+-D(

235J

(R(6(

V7GZ(=2

2J(

7D(d=22

(gtgt(amp(F=((Samp

D(ampD(1+8D(eQ22

(gtgt(8U(gtamp

18(-(

fampamp

(Oamp

D(V1(

23Qlt

=(6(

OBB

((

-(=22

Q(

N+-(B81(8D

((=

522(S

((

ggt(H

+(

32J

(6(

0

-- (

445(

]--(8S

Camp

D(-+-(B81(

ggt(H

+(

3lt(6(3(

0

-- (

ampD(G(=22

5(

7D(8(=5(gtgt(-+(1D

(Q22

(gtgt(9(amp

D(B(8

gtgt (

Table9Reportedandcalculatedgrowthratesfromtheliterature

Calculatedgrow

thratesbasedon

informationprovidedinliterature

aApproximationsofmaximum

grow

thpotential(basedon

average13 maximum

sizesiffishreportedatharvest

21

13

General Information on Factors that Affect Fish Growth

Growth in fish is extremely variable and is impacted by many different

physiological and environmental factors Growth rates are known to change with size and

age sex season activity level density amount13 of living space quality and quantity of food

genetics and temperature (Brett 1979) Growth experiments conducted at different times

of year can result in growth rates that are not comparable As fish become larger their

physiological13 potential to grow decreases making determination of growth rate dependent

on the size of the starting fish and the length of the experiment (Busacker et al 1990)

Genetic factors also have great potential to influence growth rate Some species have

strains13 and13 races13 that display vastly different growth potentials (Reinitz et al 1979) All of

these factors combine to make assessment of the individual factors controlling fish growth

difficult13

Water temperature is probably the most important variable affecting growth rate13

All of the basic functions that affect growth such as feeding digestion and metabolism are

temperature-shy‐dependent13 Growth13 is inseparably13 tied13 to13 bioenergetics13 and13 therefore13 also13

tightly tied to temperature When temperatures are below optimum daily temperature

fluctuations can stimulate growth Photoperiod is also commonly linked to water

temperature and can influence growth rates in fish (reviewed in Brett 1979)

Fish density13 is known to13 affect growth13 and13 can alter13 growth13 rates13 in several ways13

Fish that exhibit strong territorial behaviors13 or natural schooling tendencies13 will

experience reduced growth if densities are too high or too low (Brett 1979) Dominance

hierarchies where some fish feed more aggressively than others can also lead to high

variability13 in growth13 rates13 (Koebele13 1985) Crowded13 conditions13 also13 cause physical

interference13 between13 fish and13 poor water13 quality13 which13 reduces13 growth13 (Busacker13 et al13

1990) The effects of fish numbers space and feeding opportunity are frequently correlated13

and often13 difficult13 to distinguish (Brett13 1979)13

It is impossible to study the effects of environmental factors on growth without also

evaluating feed rations (Brett 1979) Amount of food quality of the diet particle size

number of feedings per day and time of feeding have all been shown to affect growth

(Busacker et al 1990) In controlled laboratory studies food is usually fed ad libitum13

22

13

(constantly available) and other variables are altered to assess impacts of environmental

factors13 on growth13 These studies13 are13 usually13 conducted13 in tanks13 or raceways13 because13

researchers must verify that food is constantly available to the fish which is difficult to do

in large pond environments where the fish and the bottom13 are often not visible (Busacker13

et al13 1990)

Specific Information13 o Razorback13 Sucker13 Growth

Variable13 growth

Growth in razorback suckers is naturally highly variable and may be a function of

their evolutionary history (USFWS13 2002)13 Minckley (1983) speculated that13 wide size

variation in a single cohort of razorback suckers may be adaptive with fast-shy‐growing13 fish

that13 reproduce at a young13 age surviving13 better in13 high discharge years and slow-shy‐growing13

smaller fish surviving better during drought periods This highly variable growth rate

makes rearing razorback suckers in a production setting difficult because fish from13 a single

cohort do not reach the target stocking size simultaneously One of the major tasks for

aquaculture is to maximize both individual growth and total production13 (Gerking13 1978)13

This becomes more difficult when the species being cultured exhibits highly variable

growth13 rates13 because of genetic influences as is the case with razorback13 suckers13

Razorback13 sucker growth13 is typically very13 rapid13 during13 the first13 year of life13 and then13

declines with age First year growth can be as low as 50 mm and as high as 350 mm (Valdez

et al13 1982 Minckley13 1983 Mueller13 1995) Razorback sucker13 grow rapidly13 for

approximately the first five or six years of life and then growth slows13 (McCarthy13 and13

Minckely 198713 Tyus 199813 Minckley et13 al 1991)13 Growth of older individuals in13 extant13 wild

populations is very13 low (Minckley 198313 Tyus 198813 Modde13 et al 1996)13 Wild growth13 rates

for mature adult fish in Lake Mohave based on PIT tag recaptures were often too small to

be accurately measured for both males and females over the time period of 1987-shy‐199713

(Marsh and Pacey 1998) This information suggest it will take substantially longer to rear

fish to13 increasingly13 larger13 stocking13 sizes (40013 ndash 500 mm TL) than it did to reach the target

size of 300 mm TL

Growth in ponds

23

13

One of the main strategies for maintaining genetic refugia and self-shy‐sustaining13

populations of razorback13 sucker in the lower Colorado13 River basin13 is to rear razorback13

sucker13 larvae13 in production13 ponds until they13 are13 a suitable13 size for stocking13 (USFWS13 2004)

Pond culture has proven useful to promote rapid growth of juvenile razorback suckers

(Kaeding and Osmundson 1989) Marsh (1994) reported that growth rates of razorback

suckers13 reared13 in golf-shy‐course13 ponds exceeded13 the13 best growth13 rates13 obtained13 under

intensive13 culture13 conditions13 at federal hatcheries13 especially13 during the13 first several years13

of life Growth rates in these semi-shy‐natural ponds are also comparable to estimated growth

rates13 of juvenile13 wild13 fish (McCarthy13 and13 Minckley13 1987) Modde13 and13 Haines13 (2005)

reported13 the13 greatest growth13 rates13 in the13 largest and13 deepest floodplains13 with13 the13 greatest

amount of submergent vegetation but excellent growth and survival of fish in a grow-shy‐out

pond is of little value if there is not an efficient way to collect the fish from13 the pond

(Kaeding and Osmundson 1989)

Temperature13

Bulkley and Pimentel (1983) used shuttle boxes in the laboratory to determine a

temperature preference13 for razorback suckers13 of 23-shy‐24degC13 In13 their13 studies13 razorback

suckers were found to avoid temperatures below 118 degC or above 286 degC Razorback

suckers at Bubbling Ponds Hatchery are more active in the spring and feed better as

photoperiod increases even prior to water temperatures rising (Frank Agygos personal

communication) Table 3 briefly summarizes water temperature data from13 each facility

Detailed seasonal water temperature profiles are not currently available for many

razorback grow-shy‐out sites13

Density13

Extensive studies have been conducted on commercially important species to

evaluate stocking densities and feeding rates that maximize production For these species

controlled experiments under laboratory conditions have established relationships

between temperature density and feed ration on growth (Brett 1979) but this information

is sporadic13 or non-shy‐existent for razorback suckers13 (Bays13 et al13 2005) Fish culturists13 with13

24

13

experience13 rearing13 razorback suckers13 typically13 have13 target stocking13 densities13 that13 they use

(Tables13 4 -shy‐ 5) These stocking densities have largely been determined over time by trial

and error These approximate stocking densities provide a good starting point for more

controlled13 types13 of replicated13 pond studies13

Feed ration

Razorback13 suckers are currently13 being13 fed a wide variety13 of prepared diets (Table 7)

that range from13 a slow-shy‐sinking salmon feed manufactured by Silver Cupreg to a spirulina

and krill-shy‐enhanced catfish feed made by Rangenreg Most locations are feeding 20 ndash 50

body13 weight per13 day13 Methods13 for culture13 of razorback sucker13 larvae13 in intensive13 settings13 at

fish hatcheries are well documented (Figiel 2005) and various larval fish diets have been

evaluated13 (Tyus and13 Severson 1990 Severson et al13 1992) but no standardized13 procedures

are used for feeding13 larval13 fish in13 intensive settings13

Razorback sucker larvae are also effectively reared in pond environments using

natural foods supplemented with larval fish diets and survival is high when no predators

are present13 (Mueller 2006)13 Growth rates for larval13 and early juvenile razorback13 suckers

may increase with pond fertilization Diet and physiological studies on wild razorback

suckers indicate that they feed on plankton as well as benthic organisms during their entire

life (Marsh 1987) Artificially fertilizing ponds may greatly increase production capacity

and growth rates for razorback13 sucker (Papoulias and Minckley13 1992) and warrants

further13 investigation13

Handling stress

Handling stress13 has13 been shown to13 influence growth13 rates13 Paukert13 et al (2005)

found that growth of bonytail chub was reduced by 26when compared with controls

after being13 repeatedly13 captured and handled in13 hoop13 nets13 Handling13 effects are likely13 to be

similar for razorback suckers that are repeatedly13 captured and sorted in13 a hatchery13 setting13

Razorback suckers that are handled at Willow Beach National Fish Hatchery will commonly

not eat for two weeks after handling (John Scott personal communication) This creates a

difficult situation13 for production13 facilities because13 fish13 need to be sorted to ensure13 large13

25

13

aggressive fish do not interfere with growth of smaller individuals but frequent handling

and sorting13 causes stress related reductions in13 growth13

Measuring Growth in Captive Fish

Weight is the traditional measure used to estimate growth or production in

aquaculture settings13 Groups of fish are typically13 weighed and an average individual13 weight13

is computed (Busacker et al 1990) Although this method is often logistically the easiest it

may not be the most informative for species with highly variable growth rates like

razorback suckers especially when target lengths must be reached before fish can be

stocked Weight can also be highly influenced by things like stomach fullness or

development of gonads (Busacker et al 1990) Condition factor or relative weight can also

be used to assess growth of fish but these tools may be more robust predictors of fecundity

than of growth (Anderson and Neuman 1996) For some species sexes need to be

distinguished because males and females may differ in morphology (Anderson and

Neumann 1996) Mueller (2006) analyzed growth rates based on PIT tag recaptures of 86

razorback suckers13 in High13 Levee Pond13 and13 found13 that differences13 in growth13 do not appear13

to occur until fish are over 450 mm TL at which time growth rate in males slows while

females continue to grow at a slightly higher rate This would indicate that sex may not be

an important factor to consider when examining growth rates unless the target grow-shy‐out

size is above 450 mm TL

The best measures of growth are often determined from13 the length and weight of

individuals rather than from13 groups of fish (Anderson and Nuemannn 1996) because

individual growth rates give better estimates of confidence and variance (Busacker et13 al

1990) Length frequency analysis or recapture of previously marked individuals of a known

size is likely to yield the most useful information for razorback sucker growth The success

of any of these methods depends on proper sampling procedures that are representative of

the population as a whole (Busacker et al 1990) Sampling methods that are known to be

size-shy‐biased such as trammel nets (Mueller et al 2004) or cast nets should not be used when

trying to measure growth rates13

26

13

Conclusions

For razorback sucker survival is largely associated with stocking size Additional

focused13 research13 is therefore13 needed to13 identify13 ways13 to13 increase13 growth13 rates13 of captive-shy‐

reared13 razorback sucker Growth13 rate13 in fish is controlled13 by many factors including fish

size and age temperature density and feed ration which can all be highly correlated

Growth of razorback suckers is also inherently variable which makes the task of identifying

the key factors that13 affect13 growth in13 captivity even more difficult The focus at most

razorback rearing facilities13 is production so the13 types13 of data that are13 collected13 are13 often

insufficient for detailed13 evaluations13 of individual rearing13 practices13 on growth13 Surveys of

existing13 razorback sucker13 rearing facilities indicate that culture methods vary widely and

the types of growth data13 that13 are collected are not13 standardized13 Replicated studies with

detailed information on rearing location water temperature initial stocking size stocking

density and the sizes of all fish at harvest are needed in order to compare the effects of

individual rearing practices on growth This type of research will ultimately provide both

time and cost-shy‐savings to production facilities by reducing the amount of time necessary13 for

razorback sucker to reach stocking size improving overall production efficiency

Optimum13 rearing densities for razorback sucker larvae and juveniles remain to be

determined Current stocking densities will be very useful as starting point for more

detailed studies and although optimum13 rearing densities are likely to be site-shy‐specific13

replicated studies on density will provide a valuable reference for hatchery managers

Frequency13 of sorting is another13 area that needs13 further13 research Frequent

handling13 and13 sorting13 can13 cause13 stress-shy‐related13 reductions13 in growth but not sorting can

create dominance hierarchies that further reduce growth rates of subordinate individuals

The effects13 of sorting13 on overall fish growth13 in both13 pond and13 intensive13 culture13

environments warrant further investigation Research techniques for these types of

experiments are well understood and typically utilize a matrix of replicate ponds per

variable (Bays et al 2005) In every case accurate and complete records of sampling

procedures and data collection are needed in order to interpret data and make inferences

about13 growth rates (Busacker et13 al 1990)13

27

13

Additional research is also needed to evaluate long-shy‐term13 survival of stocked fish

reared in ponds compared to fish13 reared13 in intensive13 culture13 facilities13 Exercise13

conditioning13 and predator-shy‐recognition training may also increase survival of stocked fish

and be more economically feasible than rearing fish to increasingly larger sizes prior to

stocking13 The success13 of traditional fish hatchery programs is measured largely by the

number of fish stocked but hatchery programs for endangered species must measure

success in terms of long-shy‐term13 survival and species recovery (Brannon 1993 Anders 1998)

A specific list of research recommendations follows

Specific Research13 Recommendations13

bull Use replicated studies13 to establish optimum stocking13 densities13 for ponds13 and

tanks13 that can be used as13 a starting13 point for site specific refinement

bull Determine if sortinggrading13 improves13 overall growth rates13 in both ponds13 and

intensive culture facilities13

bull Investigate the use of artificial fertilizers13 to improve growth of both juvenile

and adult razorback suckers13 in ponds13

bull Determine if the razorback sucker diet gives13 better growth rates13 than cheaper

catfish or salmon feeds

bull Evaluate growth rates13 and production potential of new intensive culture

methods13 such as13 large circular tanks13

bull Evaluate13 long-shy‐term survival of fish produced from raceways13 and circular tanks13

compared to fish reared in ponds13

bull Evaluate more effective means13 of treating13 fish diseases13

bull Evaluate factors13 other than size that may increase post-shy‐stocking13 survival such

as13 exercise conditioning13 predator recognition training or rearing13 under more

natural settings13

28

13

II The Effect of Disease Treatments on Razorback Sucker

Growth

Section13 SummaryFormalin copper sulfate potassium permanganate and13 salt are all chemicals commonly13 used13 to13 treat13 Ichthyophthirius multifiliis outbreaks in captive razorback sucker (Xyrauchen13 texanus) Weexposed 190 juvenile13 razorback suckers (127 ndash 26 mm TL) to13 5 5-shy‐day treatments with13 each13 chemical to evaluate the effects13 these chemicals13 may have on growth Fish grew an average of23513 mm TL13 during the month13 study period Fish treated with formalin grew on average13 29mm TL (03 mmday) while fish treated with copper had the lowest growth averaging 20 mmTL (021 mmday) No significant differences in13 growth were observed among fish treatedwith any of the chemicals compared to untreated fish (pgt005) Reductions in growth13 as aresult of repeated chemical treatments are not likely the cause of differences in growth ratesamong13 facilities that raise razorback suckers Repeated chemical treatments may13 have otherimpacts to overall13 fitness or long-shy‐term survival but13 these effects were not13 evident13 in our study

29

13

Introduction

Preservation13 of razorback sucker13 (Xyrauchen texanus) currently13 depends on captive13

rearing and stocking programs until permanent solutions to factors that prevent wild13

recruitment are found Low survival of stocked razorback suckers (Brooks 1986 Marsh

and Brooks 198913 Marsh and Pacey13 2005) has caused target13 sizes for stocked fish to

steadily increase in efforts to reduce predation mortality (Marsh et al 2005 Schooley and

Marsh 2007) Rearing fish to larger sizes at hatcheries comes with increased costs and

creates the need to evaluate husbandry and rearing practices that may affect fish growth

Formalin copper sulfate potassium13 permanganate and salt are all chemicals

commonly used at razorback sucker rearing facilities to treat outbreaks of the protozoan

parasite13 Ichthyophthirius multifiliis ldquoIchrdquo is one of the most pathenogenic diseases of

cultured13 freshwater13 fishes (Matthews13 2005) and causes large13 losses in captive13 populations13

of endangered razorback sucker Each of these chemicals used to treat Ich only kill the free-shy‐

swimming life stage of the parasite13 requiring13 repeated doses over several13 days depending13

on water temperature These chemicals treatments are needed to prevent loss as a result

of disease outbreaks but the cumulative effects repeated disease treatments have on

growth13 are13 unknown

Copper13 sulfate13 has13 been shown to13 significantly13 reduce13 growth13 of channel catfish13 in

production13 ponds (Rabago-shy‐Castro13 2006) but it is unknown whether13 razorback suckers13

experience similar reduced growth following copper treatment Quantifying the impacts of

disease treatments on growth will help to interpret the wide differences in growth rates

observed13 at various13 razorback sucker13 production13 facilities13 throughout the13 southwest

(Ward et al 2007) If one chemical is found to have less detrimental impacts on growth

than another then it may be preferred for use as a disease treatment We evaluated growth

rates13 of razorback suckers13 under13 replicated13 and13 controlled13 conditions13 to13 assess13 effects13 of

repeated formalin copper sulfate and potassium permanganate and salt treatments on

growth13

Methods

We captured 190 juvenile razorback suckers from13 ponds at Bubbling Ponds Fish

Hatchery AZ using hoop nets or cast nets All fish were of the same age class and

30

13

averaged 179 mm total length (TL) (range13 = 127 ndash 262 mm TL)13 These fish were13 offspring13

of captive13 razorback sucker13 broodstock held13 at Dexter13 National13 Fish Hatchery13 NM13 (2007

year class) All fish were tagged with passive integrated transponder (PIT) tags and

quarantined for one month prior to the experiment to allow fish to recover from13 tagging

and become accustomed to being held in circular tanks

At the beginning of the study all fish were weighed measured and scanned for

individual tag numbers with 19 randomly selected fish placed into each13 of 10 8-shy‐foot

diameter circular tanks (Figure 2)13 Each13 tank contained13 two13 airstones13 and13 an13 individual

biofilter with a recirculating water pump (31 litersminute) that had been operating for

at least 1 month prior to the experiment to allow bacterial colonies to become

established Two tanks were designated as a control and did not receive any chemical

treatments while the other eight tanks received formalin copper sulfate potassium13

permanganate or salt treatments at two week intervals (two tanks per chemical

treatment) Formalin copper sulfate and potassium13 permanganate were treated at 1 part

per million (ppm) and salt was applied at 30 parts per thousand (ppt) These treatment

rates are commonly used to treat13 razorback13 suckers for ich at Bubbling13 Ponds Fish13

hatchery (Frank Agygos personal communication)

Figure 213 Photo ofexperimental tankswith individualbiofilters and aeration

31

13

Each treatment consisted of a series of doses applied on Wednesday Thursday and

Friday with a 90water change between each dose Biofilters were removed from13 all

tanks and held in a separate holding facility during treatments and then replaced on the

Monday following treatments after a 90water change This schedule allowed fish to be

exposed to chemical treatments for 5 consecutive days without water quality deteriorating

This 5-shy‐day chemical treatment was repeated every two weeks from13 July to October (97

days)13 for a total of 5 5-shy‐day treatments Water temperature in the treatment tanks ranged

from13 13degC (55degF) to 32degC (91degF)

Fish were fed a fixed ration of commercial razorback diet (Silvercup 4mm13 pellet)

once daily13 (2 percent body13 weight per day13 as calculated13 by13 average initial fish weight)13

At the end of the experiment all fish were again weighed measured and scanned for

individual tag numbers Growth of fish in each treatment group was compared using

analysis of variance (ANOVA) Any mortalities13 that occurred during the13 study13 were13

replaced with previously quarantined fish of equivalent size to maintain equal densities in

each13 tank13 but growth13 data was13 only13 recorded for fish which13 survived13 the13 entire13

experiment

Results

Fish at the13 start of the experiment averaged 179 mm TL (Range13 = 127 ndash 262 mm)

with no significant differences in fish length among treatment groups (F(4189) = 00183 p

gt 0999 ANOVA) On average fish grew 235 mm TL (024 mmday) during the 3 month

study13 Fish in tanks13 treated with formalin had the highest growth averaging 29 mm TL (03

mmday) while fish in tanks treated with copper had the lowest growth averaging 20 mm

TL (021 mmday) Fish in the control tanks averaged 213 mm TL in growth (022

mmday) (Figure13 3)13 Formalin-shy‐treated fish grew13 significantly faster than13 any other

treatment group but no13 significant differences in growth13 in length13 or weight were13

observed among fish treated with any of the chemicals compared to untreated (control)

fish (pgt005 ANOVA)

32

13

Figure 313 Average growthof razorback suckersexposed to a series of 5 5-shy‐day chemical treatmentsover a 97-shy‐day13 periodError bars representstandard error

Discussion13

Growth13 rates13 observed13 in our study13 (021 ndash 03 mmday) are low compared to those

reported13 in other13 studies13 of razorback sucker13 growth13 (0213 ndash 18 mmday) (Ward et al

2007) Using recirculating water systems for our study required filters to be removed and

replaced during treatments Stress to fish caused by removing and replacing filters within

the tanks as well as repeated water changes may have led to overall higher stress and

reduced growth rates compared to those reported for unconfined fish Growth in fish is

highly variable and is affected by many different physiological and environmental factors

including fish size density temperature amount of space and food (Brett 1979) We

strived to control each of these factors but other factors may have also influenced growth

in our experimental tanks During mid-shy‐summer water temperatures in the treatment

tanks reached 32degC (91degF) At these warm13 temperatures fish are very susceptible to

bacterial13 infections13 The slightly higher growth exhibited by fish in the formalin and

potassium13 permanganate treatments may have been the result of these two chemicals

33

13

being effective at controlling bacterial infections The differences in growth we measured

among treatment groups were not statistically significant and do not appear13 biologically13

meaningful during the relatively short duration of this study (97 days) although the

cumulative effects of slightly reduced growth could be biologically meaningful over longer

time frames

Reductions in growth13 as a result13 o repeated chemical treatments are not likely the

cause of differences in growth rates among facilities that raise razorback suckers

Repeated chemical treatments may have other impacts to overall fitness or long-shy‐term13

survival but these13 effects13 were13 not evident in our study It is more likely that the parasite

outbreaks themselves are the cause of different growth rates among razorback rearing

facilities rather than the chemical treatments used to treat the parasites We recommend

that hatchery managers continue to use the chemicals that are most effective at controlling

ldquoIchrdquo13 at their individual13 facilities

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower Colorado Rive Multi-shy‐species13

Conservation Plan under Work Task C10 We thank Ty Wolters and Tom13 Burke for their

support of this research and Frank Agygos and Dave Billingsly of the Bubbling Ponds Fish

Hatchery13 for their13 technical assistance13 and13 help with13 collecting13 fish

34

13

III13 Razorback Growth Rates at Bubbling Ponds ndash 2009-shy‐2011

Section13 SummaryExperimental studies at Bubbling Ponds Fish Hatchery AZ have strived to understand

factors that affect razorback sucker growth in captivity and identify ways to improve growthrates and maximize size at release Rather than performing experimental studies that wouldrequire major13 rearrangement (and likely reduced production)13 of hatchery operations our13 studies13 used normal variation in production techniques13 and practices13 to isolate factors13 thatmay modify growth rates

Our initial work identified razorback13 growth rates in13 lined ponds at standard fishdensity as 026 to13 028mmday (789 to 843 mmmonth) No significant differences in growthrate were observed among fish that had been in the pond only during the winter13 periodcompared to fish that had been in the pond the entire year indicating that water temperatures13 at Bubbling Ponds are high enough to allow fish to incorporate feed effectively year-shy‐roundHowever these growth rates are lower than most values reported from the literature fromnatural or semi-shy‐natural pond environments No significant differences in13 growth rate wereobserved13 between large and13 small fish13 within the 150 ndash 29 mm TL13 size range Additional worksuggests13 that razorback suckers13 tagged at over 300 mm TL had reduced growth rates (024mmday 73 mmmonth) as would be expected according to a typical Von13 Bertalanfy growthcurve although growth rates13 were only slightly less13 than the average growth rate for thehatchery (027513 mmday 82513 mmmonth)

Sorting13 to13 separate small fish from large fish after the first year of growth is practicedesigned13 to allow smaller fish to ldquocatch uprdquo to larger fish We found that13 this technique doesappear to13 improve growth rates of smaller fish Growth rates of sorted small razorback suckers(029 mmday 87mmmonth)13 were equal to that13 of larger13 fish (028 mmday 8413 mmmonth)indicating that sorting may have helped to offset their original slower growth trajectory

Bubbling Ponds Fish Hatchery grows razorbacks in 6 long deep ponds lined with heavyplastic 2 long deep13 earthen13 (unlined) ponds and three wide shallow earthen ponds The wideshallow ponds13 have historically produced very large fish at low density but have been found tomaintain much lower fish numbers than deeper ponds We found13 that growth13 rates ofrazorbacks kept at high density (4-shy‐700013 fish)13 in a wide shallow pond grew extremely slowly(024 mmday 726 mmmonth) This growth rate is among the slowest of any fish over theyears of our study and demonstrates that13 though the large ponds may produce large fish at lowdensity13 they are unable to overcome high13 fish13 densities

Finally one of the major factors influencing13 fish13 growth13 in hatcheries is disease onemajor summer-shy‐time disease at13 Bubbling Ponds is the ectoparasite Ich (Ichthiopthirusmultifiliis) To investigate the impact Ich has on razorback growth we eradicated fish from thespring and water conveyance ditch that supplies13 water to the hatchery using Rotenone This13 restoration effort was fairly short-shy‐lived (Ich returned to the hatchery within four months) but

35

13

growth13 rates of fish13 reared for four months without Ich present (031 mmday 92 mmmonth)were significantly higher than the following 8 months of growth for those same fish (022mmday 65 mmmonth) This disease-shy‐free growth rate is in fact faster than any13 otherprevious growth rates observed at the hatchery in our study

We conclude that growth rates at the Bubbling Ponds Fish Hatchery are likely as highas possible given the pond densities required to13 meet production goals and the Ich-shy‐infestedwater13 that feeds the facility Sorting practices are successful in helping as many fish as possiblereach stocking length as fast as possible Unlined ponds may be able to grow large fish at lowdensities but whatever factors allow for that growth13 are not able13 to overcome13 high fish densityThus the large lower ponds at Bubbling Ponds may be better utilized via renovation to13 deepenand line them

Disease is the most important factor limiting growth as may be expected to be the caseat many13 hatcheries While the spring renovation was not13 a complete success13 the dramaticreduction of fish populations in that habitat was enough to dramatically13 reduce13 the13 occurrenceof Ich at the hatchery13 Such open spring13 systems feeding a hatchery are a misfortune that canbe expected to transmit disease so we suggest that renovating the spring again to combat13 IchImproved techniques to divert water from13 the springs and more throuough treatment ofstream-shy‐side vegetation may improve the success of chemical treatment Successful renovationwould likely both improve growth rates and reduce chemical costs associated with treating Ichoutbreaks Even13 if complete renovation13 is impossible or impractical an13 effort to reduceinvasive fish density in the springs13 which act a vector for the parasite(and thereby reduce thelikelihood of13 Ich being transmitted into ponds) may still13 show dramatic improvements

36

13

Introduction

Conservation efforts13 for razorback sucker13 (Xyrauchen texanus)13 currently13 depend on

captive rearing and stocking programs Low survival of stocked razorback suckers (Brooks

1986 Marsh13 and13 Brooks13 1989 Marsh13 and13 Pacey13 2005) has13 caused13 target sizes for stocked13

fish to steadily increase in efforts to reduce predation mortality13 (Marsh13 et al13 2005

Schooley and Marsh 2007) Rearing fish to larger sizes at hatcheries comes with increased

costs and creates the need to evaluate husbandry and rearing practices that may affect fish

growth13 We evaluated growth13 rates13 of individual razorback suckers13 in ponds13 at Bubbling

Ponds Fish Hatchery13 using Passive Integrated13 Transponder (PIT) tags13 to13 obtain13 precise

growth information for individual fish so that valid comparisons of growth rates as related

to rearing practices can be made

Due to the critical nature of the razorback sucker stocking program we did not

design experimental studies that would require major rearrangement and potentially

reduce production of hatchery operations Instead our studies used normal variation in

production techniques and practices to isolate factors that may modify growth rates

Though this methodology dramatically limits replication and may limit our ability to

directly13 attribute13 differences in growth13 rates13 to13 the13 variables13 we13 investigate13 we13 were13 able13

to accomplish research goals without altering hatchery operations or impacting

production

From13 2009 through 2011 we conducted a series of observational13 growth13 studies to

determine growth rates of individual razorbacks at Bubbling Ponds The first set of

experiments included13 identifying13 growth13 rates13 in lined13 and13 unlined13 ponds determining

growth13 rates13 of fish at different13 sizes13 in13 relation13 to sorting13 practices and monitoring

razorback growth rates after removing the source of the ectoparasite13 Ich (Ichthiopthirus

multifiliis) from13 the hatchery water source13

Razorback growth rate in lined ponds

Our first growth study documented individual growth rates at normal density in 11

million gallon lined ponds13 over two13 years13 This is the standard13 grow-shy‐out process for

razorbacks13 at Bubbling Ponds We monitored growth of fish for a variety13 of sizes and13 the13

37

13

amount of time in a pond during the growing season These13 data give a snapshot of growth13

rates13 at the13 facility13 and13 provide13 the basis for comparisons throughout our study

Growth rate13 in an unlined pond

In addition13 to 6 ponds lined with heavy plastic13 sheeting13 Bubbling Ponds Fish13

Hatchery maintains two narrow and deep (same dimensions as lined ponds13 Figure13 4)13 and13

three large13 shallow unlined ponds These earthen13 ponds typically have vegetation and

associated aquatic invertebrates that may better simulate natural environments by

providing cover and improved food diversity or quality Therefore these unlined ponds

may be expected to produce higher growth rates and potentially improved survival that is

more similar to growth rates observed in more natural grow-shy‐out facilities13 Historically13 the13

large13 shallow13 ponds have produced very large fish when13 utilized at low13 fish density13 The

narrow13 deep earthen13 ponds are13 used to grow13 fry13 at high density in their first13 year of life

The major downside to unlined ponds is the difficulty in harvesting fish where a lined

pond might take 8-shy‐1013 people13 a half13 day13 to13 harvest13 lined13 ponds13 require13 intensive13 weeding13

to allow seines to be pulled and therefore require many more personnel-shy‐hours13 In addition13

to harvest challenges the shallow earthen ponds tend to suffer from13 dissolved oxygen

crashes during the summer Unlined ponds also may maintain higher13 populations13 of non-shy‐

target species such as bluegill sunfish mosquito fish and bullfrog tadpoles We measured

growth rates of suckers in a large shallow earthen pond for comparison to growth in lined

ponds13

Figure13 4 Lined13 and13 earthen ponds13 of similar dimensions (approx 1000000 gallons first

and second panels) and a large13 shallow13 earthen13 pond (third panel)

38

13

Effect of sorting on growth

Razorback13 suckers13 are13 currently13 sorted13 after their first13 year of growth13 They are13

typically removed from13 one of the13 upper earthen13 ponds and13 split into13 two13 lined13 ponds for

subsequent grow-shy‐out13 The larger13 fish (gt approximately 140 mm) are placed into one pond

and the smaller individuals in another It is possible that the larger fish were more

aggressive or adept13 at taking food so this sorting process is intended to allow smaller fish

to improve their growth rate

Effect of Ich on razorback sucker growth rates

We13 evaluated13 growth13 rates13 of razorback sucker13 in the13 presence13 and absence of the

ectoparasite13 Ich (Ichthiopthirus multifiliis) Ich outbreaks can occur in wild populations13 but

hatcheries13 have13 proven excellent locations13 for Ich because13 of very high fish densities13 which13

facilitate13 the13 transfer13 of Ich13 between13 fish This common fish parasite causes direct mortality13

to razorback13 suckers as well13 as secondary bacterial13 infections13

The open spring and13 ditch13 which13 provides water to the Bubbling13 Ponds Hatchery

has long13 been infested with mosquitofish (Gambusia affinis) that harbor13 the13 Ich parasite13

and allow13 it13 to enter the hatchery with incoming13 water13 The solution13 to13 the13 Ich problem13

was to remove the mosquitofish host using13 Rotenone Razorback13 sucker growth13 rates were13

then tracked in13 the absence of this parasite for 4 months and compared with growth rates

after Ich returned to the pond and from13 previous years

Methods

Razorback growth rate in lined ponds

On May 14 2008 141 razorback suckers were tagged with 12 mm PIT tags (1342

kHz) and placed in Pond 3 (approximately 1100000 gallons13 Figure13 4)13 at Bubbling13 Ponds

Fish Hatchery Fifty-shy‐three of these tags were recovered two months later when a large

Ichthyophthirius multifilis (Ich) outbreak killed many fish in the pond On October 15 2008

an additional13 145 PIT tagged13 fish were13 also placed into Pond13 3 On13 May13 14 2009 Pond13 3

was harvested and a total13 of 141 PIT tagged fish were recovered13 Of the tagged fish13 26 fish

had13 been13 in the13 pond since May13 of 2008 (378 days13 o growth) and 115 had been13 in13 the

39

13 40

pond since October13 15 2008 (211 days13 of growth) Numbers of fish in Pond 3 after the Ich

outbreak and for the majority of the period of growth were between 3 000 and 4000 fish

A Hobotempreg temperature13 logger13 was13 also13 installed13 in Pond 3 one meter below the water

surface13 near13 the13 outflow and13 recorded water temperature every 3 hours to allow analysis

of the effects of water temperature on growth rate (Figure13 5) This Hobotemp data is

representative of other pond temperatures throughout this study

In a second experiment 210 adult13 razorback suckers13 were13 PIT tagged13 on13 May 14

2009 and13 placed13 into13 Pond13 3 upper to13 evaluate13 growth13 rates13 of larger13 razorback suckers13 at

Bubbling13 Ponds Hatchery13 under current13 rearing13 conditions13 Size of these fish at tagging13

was (mean = 285 mm range = 205 ndash 396 mm) These fish remained in the pond for 257

days and were harvested on Jan 25 2010 to provide information on growth rates of larger

razorback suckers13 under13 current rearing conditions

Figure 513 Temperatures (degC) inrearing pond at BubblingPonds Hatchery from July toSept 2009 (top graph)13 andfrom Nov to Dec 2009 (Lowergraph) Temperaturesrecorded with a Hobotempregremote data logger13 every 3hours

13

Growth rate13 in an unlined pond

To document razorback sucker growth in earthen ponds we introduced13 225 tagged13

razorback suckers13 into13 Pond13 1 lower13 (Figure 4) in February 3 2010 Additional tagged fish

from13 other studies were added to the pond throughout the growing season and the density

of 1 lower reached a maximum13 of nearly 7000 fish in early summer 2010 Density was

reduced to approximately 6000 fish by capturing fish with hoop nets on June 3 2010 54 of

these fish were tagged fish and returned to 1 lower after being weighed and measured The

pond was harvested on January13 2713 2011 and a total13 of 254 tagged fish out13 of 4296 fish

total were removed from13 the pond The pond was harvested on January 27 2011 (358 days13

of growth) and the tagged fish were weighed and measured Total number of razorbacks in

the pond at harvest13 was 4296

Effect of sorting practices on growth rates

On March 1113 200913 Pond13 5 upper was13 harvested13 and13 split into13 two13 separate13 groups

Two hundred of the smaller fish (average size = 122 mm TL) were PIT tagged and placed

into13 Pond13 7 upper and13 200 of the13 larger13 fish (average = 160 mm TL) were PIT tagged and

placed int Pond13 8 upper Density13 in Pond13 7 was13 4500 fish and13 in Pond13 8 there13 were13 6500

fish These ponds were then harvested after 1 year and growth rates were compared to

give information on the effects of current sorting practices Hobotempreg temperature

loggers were installed in13 Ponds 7 and13 8 during13 the13 grow-shy‐out period with13 water13

temperature recorded every 2 hours13 (Figure13 6)

Effect of Ich on razorback sucker growth rates

Bubbling Ponds spring was treated with Rotenone (CFT Legumine 5) at a

concentration of 2 ppm13 to remove all mosquitofish from13 the spring The treatment

consisted of two treatments 6 hours in duration on two consecutive days (April 12 -shy‐ 13)

using13 drip13 stations13 and13 backpack sprayers13 followed13 by13 an13 additional 6 hours13 of

detoxification using sodium13 permanganate Although 12 mosquitofish were captured in the

spring pond the week following the treatments subsequent minnow trapping (20 traps

checked13 daily13 for 3 weeks) did not capture any additional fish until August 11 2010 when

41

13

juvenile mosquitofish were again detected in the spring pond Minnow traps have

subsequently been set daily with several hundred individuals removed To evaluate if Ich

was also again present in the spring we captured 15 mosquitofish from13 the spring pond on

three separate days and placed them13 in an aquaria at 25 degC with 5 longfin dace known to be

free of Ich These fish were monitored for 2 weeks with no signs of Ich developing This

indicates that even though mosquitofish have returned to the spring pond the parasite is no

longer present13 although how13 long13 this condition13 will13 persist13 is unknown13

On May 1113 201013 200 juvenile razorback13 suckers were harvested out13 of Pond 5

upper (2009 year Class from13 Dexter National Fish Hatchery) and were PIT tagged and

placed into Pond 8 to evaluate if growth rates at bubbling ponds hatchery have improved

following the renovation of the spring and the removal of the Ich parasite Unfortunately13

on Sept13 8 2010 Ich was13 again13 detected13 in Pond 8 and the pond was immediately seined

and 74 tagged fish were measured to obtain growth information for the 4-shy‐month period

during13 which13 the13 pond13 was13 Ich-shy‐free13

Figure13 6 Temperatures (degC) in rearingponds 7 and 8 at Bubbling Ponds Hatchery13 from March 2009 ndash March 201013 pond 7(top13 graph)13 and13 pond 8 (Lower13 graph)13 Temperatures recorded with a Hobotempregremote data logger every 3 hours

42

13

Results

Growth in Lined Ponds

Razorback suckers13 that had been13 in13 Pond 8 upper for the13 entire13 year13 grew an13

average of 0263 mmday (789 mmmonth) and razorback suckers that had been in the

pond for 7 months (Oct -shy‐ May) grew13 on13 average of 028 mmday (843 mmmonth) (Figure13

7) These growth13 rates13 did not significantly13 differ Fish density13 in Pond 3 during13 the13

majority of the growth period was13 00032 ndash 00036 fishgallon13 Additionally no13 significant

differences in growth rate were observed between fish smaller than 210 mm TL and fish

larger than 210 mm TL when all recaptured fish were combined

We also measured the growth rate of very large fish in a lined pond On Jan13 2513 201013

156 adult fish with PIT tags were recovered from13 Pond 3 upper13 These fish were13 in the13

pond for 257 days and experienced an average13 growth13 rate13 of 024mmday or 73

mmmonth (Figure13 7)13 This growth13 rate13 is slightly13 lower13 than13 the13 average13 growth13 rate13

observed13 at Bubbling13 Ponds Hatchery in other studies (0275 mmday 825 mmmonth)

but may not be biologically meaningful We would expect larger13 fish to13 have13 reduced

growth rates according to a typical Von Bertalanfy growth model (Bertalanffy 1957) but it

appears that13 over the size range we evaluated (300 -shy‐ 450 mm TL) growth rates have not

slowed significantly compared to that of smaller13 fish grown at Bubbling Ponds13 Hatchery

Growth13 of razorback suckers13 is known13 to13 slow as13 fish reach13 larger13 sizes but it appears13 this13

reduced growth rate may not really start to be biologically meaningful at Bubbling Ponds

Hatchery13 until razorback suckers13 exceed 450 mm TL

Growth in unlined ponds

Growth13 rates13 for the13 fish recaptured13 during13 the Pond 1 lower13 thinning13 (120 days13 in

the pond) was 024 plusmn 003 mmday (729 plusmn 090 mmmonth) (Figure13 8)13 Fish13 that were13 in

the pond for nearly the entire year grew13 an13 average13 of 024 plusmn 001 mmday (726 plusmn 027

mmmonth) These growth rates are surprisingly the lowest measured growth rates for

any part of our study and differ significantly from13 every other measured growth rate

except very large13 fish (Figure13 9)13 Separating13 out13 large fish that13 were in13 the pond for the

entire year makes no difference fish that were added to the pond at TL lt300 mm grew

43

13

Gro

wth

Rat

e (m

md

ay)

020

026

032

0244 plusmn 001 mmday (733 plusmn 028 mmmonth) and and those with TL gt= 300 mm at the

start of the experiment grew 022 plusmn 003 mmday (651 plusmn 101 mmmonth)

Razorback Growth Rates in Lined Ponds

Figure 7 Growth ofrazorback suckers in(mmday plusmn standard error)in Pond 8 upper in 2008-shy‐2009 An ANOVA did notdetect any significantdifferences

7 Months Full Year 300+ mm fish

Effects of sorting on growth

One hundred and seventy five tagged razorback suckers were recovered from13 Pond

8 upper13 on March13 24 2010 (378 days13 of growth)13 These were13 the13 larger sorted13 fish (gt140

mm TL) that came out of Pond13 5 on March13 11 2009 One13 hundred and13 twenty13 two13 tagged13

razorback suckers were also recovered from13 Pond13 7 upper on March13 31 2010 (385 days13 of

growth)13 These were13 the13 smaller sorted13 fish (lt140 mm TL) that came out of Pond13 5 on

March 1113 200913 No significant differences in growth rate (mmday) were observed among

larger fish in Pond 8 and smaller fish in Pond 7 (pgt005 ANOVA) (Figure 10)13 indicating

that13 sorting may have helped to offset the original slower growth trajectory of the smaller

fish Temperatures of Ponds 7 and 8 upper remained similar throughout the year13 (Figure

5)

44

13

13

13

Gro

wth

Rat

e (m

md

ay)

Gro

wth

Rat

e (m

md

ay)

020

026

032

020

026

032

Razorback Growth in an Unlined Pond

Figure 8 Growth of razorbacksuckers (mmday plusmn standard error) in Pond 1 lower (an unlined pond)in 2010-shy‐2011 An ANOVA did notdetect any significant differences

6 Months 12 Months lt 300 mm Fish 300+ mm Fish Growth Growth

Lined vs Earthen Ponds 1 year of growth

Figure 9 Growth of razorbacksuckers (mmday plusmn standard error) in lined and unlined ponds A t-shy‐test13 did not detect a significantdifference

Lined Pond Unlined Pond 1 Yr Growth 1 Yr Growth

45

13

Effect of Sorting G

row

th R

ate

(mm

day

) G

row

th R

ate

(mm

day

)

032

020

026

032

020

026

Smaller Fish Larger Fish

Effect of Ich

Figure 10 Average growthof razorback suckers(mmday plusmn standard error)that were size-shy‐sorted intosmall fish (pond 7) and largefish (pond 8) populations At-shy‐test did not detect asignificant difference

Figure 11 Average growth ofrazorback suckers (mmday plusmnstandard error) after Ich wasremovd from the hatcheryrsquos springand after Ich was again detected inthe pond The growth rate withoutIch is significantly higher than boththe rate after Ich and the ourstudyrsquos average annual growth ratein lined ponds (ANOVA p =00003)

Growth without Ich Growth With Ich Average Annual 4 months 4 months Growth Rate

46

13

Effect of Ich on razorback sucker growth rates

Seventy-shy‐four13 tagged13 razorback suckers13 were13 recovered from13 Pond 8 on September

15 2010 These fish had13 been13 in the pond for 4 months and experienced a growth rate of

032 mmday or 97 mmmonth (Figure13 11)13 This growth13 rate13 is significantly higher (p =

005 two sample t-shy‐test) than the mean growth rate for the same group13 of tagged fish after

Ich detection (022 mmday or 65 mmmonth) and significantly higher than any other

individual growth13 rates13 observed13 to13 date13 at Bubbling13 Ponds Hatchery13 (Figure13 11)13 If this13

growth13 rate13 were13 extended throughout13 the entire13 year13 fish on average from13 Ich-shy‐free13 ponds13

would be 16 mm longer than fish from13 ponds infested with Ich Studies conducted at

Bubbling Ponds hatchery in 2008 (Ward 2008) did not reveal any effects of the treatment

chemicals on razorback sucker growth rates so it13 is likely that13 the parasite outbreaks

themselves are causing reducing growth rates rather than the chemicals used to treat the

parasites13

Conclusions

Our results suggest that under typical hatchery operations (maximizing number of

fish produced)13 the growth13 rate13 of razorback13 suckers13 is relatively13 consistent at Bubbling13

Ponds hatchery13 at 02-shy‐03 mmday (6-shy‐9 mmmonth)13 but is lower than growth13 rates13 at

other13 facilities (02 ndash 18 mmday Ward et al 2007)13 This growth13 rate13 has13 been13 constant in

both lined and unlined ponds and at all fish densities we were able to measure To achieve13

growth13 rates13 substantially higher than this will likely require13 significant changes in rearing

practices that may not be practical in order to reach numerical production13 goals

Temperature is a key variable in fish growth but seasonal growth patterns

described13 above13 (Figure13 5) demonstrate that water temperatures are high enough in

winter to maintain razorback growth Differences in water temperature by season

currently13 do not fluctuate more than 10degC at Bubbling Ponds because of the continuous

supply of water flowing through each pond (approx 225 gallonsmin) These high water

flows appear to keep pond temperatures within the thermal preference13 for razorback

suckers13 (1213 -shy‐ 28 degC Bulkley and Pimentel 1983) throughout the entire year with

temperatures rarely dropping13 below 16deg13 C (Figures 513 6)13

47

13

Fish density is another key variable in fish growth and though the number of fish in

a pond during our study ranged from13 3000 to 700013 fish we13 did not find any13 correlation13

between13 density and growth rate13 This might yield two conclusions First13 razorback

growth13 may be changed equally13 by13 densities13 at the13 hatchery13 (ie13 a density13 of 3000 fish in a

pond is as stressful13 for razorbacks as a density13 of 7000 fish) An alternative is that other

factors13 such as disease outbreaks have13 stronger13 control over fish growth13 than13 density13

Fish density13 would13 have13 to13 be13 experimentally manipulated to test13 this13 and hatchery

operations (producing the maximum13 number of fish) prevented our manipulating density13

in ponds for this13 work The trouble with manipulating density demonstrates the difficulties

associated with changing13 hatchery13 practices experimenting with density would have

prevented BPH from13 meeting13 production13 goals Given that the stocking of smaller

razorbacks has met with very little success perhaps BPH goals could be changed from13

producing 12000 fish at 300+ mm per year to a smaller number of very large fish each

year Growing13 fewer13 larger13 fish could potentially be accomplished in the same time frame

as more smaller fish but a better understanding of how density alters growth rate would

be required to be confident13 of this

The very slow growth13 in the13 earthen13 unlined13 Pond 1 lower13 was very surprising We13

had13 anticipated13 that the13 diversified diet13 cover and13 other13 habitat features13 provided by13

unlined ponds would yield dramatically increased growth rates However these traits were

not enough to offset high fish densities and in fact the unlined pond in our study13 suffered

mortality to bring densities down to that observed normally in lined ponds

Our data13 suggest13 that razorbacks13 sucker13 growth13 rates13 are13 higher in lined13 ponds13

However we13 think the reasons13 for the13 very slow growth we observed13 in the13 unlined13 pond13

in our study13 is instead13 linked13 to13 the13 usage13 of Pond 1 lower13 during13 the13 study13 rather13 than13

intrinsic13 slow growth13 in earthen13 ponds First the pond was at extremely high density for at

least part of the study The volume of Pond 1 lower has not been estimated but hatchery

managers suggest 1500-shy‐2000 fish is an appropriate number of individuals so this pond

was at a very high density for much of the experiment Second dissolved oxygen is often

very low in the13 large13 earthen13 ponds during the heat of summer much lower than that of

lined ponds This will both limit the number of fish that can survive in the pond and almost

certainly13 increases stress13 of these13 fish potentially13 reducing growth13 The DO crashes also13

48

13

limit the amount of feed hatchery managers can give fish in these ponds sometimes for

days or weeks at a time which further reduces growth during warm13 weather

Our data13 suggests that13 growth rates at the Bubbling13 Ponds Fish Hatchery are likely

as high as possible given13 the pond densities required to meet production goals and the Ich-shy‐

infested water that feeds the facility Sorting practices are successful in helping as many

fish as possible reach stocking length as fast as possible Unlined ponds may be able to

grow13 large13 fish at low13 densities13 but whatever factors allow13 for that13 growth are not13 able to

overcome high fish density The removal of invasive13 fis that act as13 a host for the13 parasite13

Ich fish from13 the Bubbling13 Ponds spring13 allowed the highest13 growth rate at 032 mmday13

(96 mmmonth) but that growth rate decreased again as Ich re-shy‐infested13 the13 hatchery13

Consistently13 achieving13 growth13 rates13 as high or substantially13 higher than13 this13 will likely13

require13 significant changes in rearing practices that may not be practical in order to13 reach13

numerical production13 goals

Two major changes that might result in higher growth rates are substantially

reducing fish density and modifying the way spring water is delivered to the facility (via

either repeated chemical treatments or enclosed concrete water diversions) to eliminate

Ich from13 the hatchery source water Other potential changes not address by our work

include13 flow-shy‐training razorbacks much previous literature including MSCP-shy‐funded13 work

on razorback suckers13 suggests13 that fish growing13 in flowing water will grow13 faster than fish

in still water (Jorgensen and Jobling 1994) Furthermore there are a wide variety of

potential benefits associated with growing13 fish13 in flowing13 water in addition13 to increased

growth13 rates13 (Davidson13 199713 Castro13 et al13 2011) Another option13 for increasing13 growth13

rates13 include13 changing to13 intensive13 culture13 in large circular13 tanks

Finally given that the stocking of smaller razorbacks has met with very little

success13 perhaps13 BPH13 goals13 could13 be13 changed from13 producing 12000 fish at 300+ mm per

year to a smaller number of very large fish each year Growing fewer larger fish could

potentially be accomplished in the same time frame as more smaller fish but a better

understanding13 of how density13 alters growth13 rate13 would13 be13 required to13 be13 confident of this

49

13

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower13 Colorado13 River Multi-shy‐Species13

Conservation Program13 (LCRMSCP) under Work Task C10 We13 thank Ty Wolters13 Tom13

Burke13 and Eric13 Volkman for their support of this research and Frank Agygos and Dave

Billingsly13 of the Bubbling13 Ponds Fish Hatchery13 for their willingness to participate in13 this

research13 and13 for their technical assistance We also thank the LCRMSCP fish group from13

Boulder City13 NV for their assistance with harvesting13 ponds and tagging13 fish13

50

13

Literature13 CitedAnders P J 1998 Conservation aquaculture and endangered species can objective science13

prevail13 over risk13 anxiety Fisheries 23(11) 28-shy‐31

Anderson R O and R M Nuemann 1996 Length weight and associated structural indicesPages 447 ndash 482 in B R Murphy13 and D13 W Willis13 editors13 Fisheries techniques13 2ndedtion American Fisheries13 Society13 Bethesda13 Maryland

Bain M B J T Finn and H E Brooks 1988 Streamflow regulation and fish communitystructure13 Ecology13 69382-shy‐392

Bays J H Zarbock R Whitman and T Murphy 2005 Conceptual design and managementof native13 fish refugia on the13 lower13 Colorado13 River In13 CL Spring13 and13 S Leoneditors Proceedings of two symposia Restoring native fish to the lower ColoradoRiver13 interactions13 of native and non-shy‐native13 fishes 13ndash1413 July13 1999 Las13 Vegas13 Nevada13 Restoring13 natural function within a modified riverine environment thelower Colorado River13 8ndash913 July13 1998 U S Fish and13 Wildlife13 Service Southwestern13 Region Albuquerque New Mexico Pages 167-shy‐177

Bertalanffy L Von 1957 Quantitative laws in metabolism13 and growth13 Q Rev Biology 32217 ndash 231

Bingham T B Scheer and C McAda 2003 Propagation facilities in Grand Valley (24 RoadHatchery Horsethief13 Ponds and13 grow-shy‐out ponds) for captive13 rearing13 ofendangered13 fishes for the13 upper13 Colorado13 River basin13 Colorado River RecoveryProgram FY2003 annual project report13 US Fish and13 Wildlife13 Service GrandJunction13 4pp

Birchell G J and K Christopherson 2004 Survival growth and recruitment of larval andjuvenile razorback13 sucker (Xyrauchen texanus) introduced13 into13 floodplain13 depressions13 of the13 Green River Utah13 Final report13 Upper13 Colorado13 RiverEndangered Fish Recovery Program13 Project No C-shy‐6RZ Publication Number 04-shy‐1513 Utah13 Division of Wildlife13 Resources Salt Lake13 City13 Utah13 67 pages

Brannon E L 1993 The perpetual oversight of hatchery programs Fishery Research 1819-shy‐27

Brett J R 1979 Environmental Factors and growth pages 599-shy‐67513 InW S Hoar13 D13 J13 Randall and J R Brett (eds) Fish Physiology Volume 8 Bioenergetics and GrowthAcademic Press New York

Brooks J E 1986 Annual reintroduction and monitoring report for razorback suckerXyrauchen texanus in the Gila River Basin Arizona 1985 US Fish and WildlifeService13 Offices of Endangered13 Species and Fishery13 Resources Albuquerque 23 pp

51

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Brunson13 R E and K D13 Christopherson13 200513 Larval13 razorback13 sucker and bonytailsurvival and13 growth13 in the13 presence13 of nonnative13 fish in the13 Baeser13 floodplainwetland of the middle Green River Final report prepared for Upper13 Colorado RiverBasin Endangered Fish Recovery Program Project No C-shy‐6-shy‐rz-shy‐bt Publication13 No 05-shy‐26 Utah13 Division of Wildlife13 Resources13 Vernal13 32 pp

Bulkley R V and R Pimentel 1983 Temperature preference and avoidance by adultrazorback suckers Transactions of the American Fisheries Society 112601-shy‐607

Burke13 T13 199513 Rearing13 wild razorback13 sucker larvae in13 lake-shy‐side13 backwaters13 LakeMohave ArizonaNevada Proceedings of the Desert Fishes Council 2635

Busacker G P I R Adelman and E M Goolish13 199013 Growth13 Pages 363 ndash 387 in C BSchreck and p B Moyle editors Methods for fish biology American FisheriesSociety Bethesda Maryland

Castro V B Grisdale-shy‐Helland S J Helland T Kristensen S M Jorgensen J Helgrud13 GClaireaux A P Farrell A Krasnov and H Takle 2011 Aerobic training stimulatesgrowth and promotes disease resistance in Atlantic salmon (Salmo salar)Comparative Biochemistry and Physiology -shy‐ Part A Molecular amp IntegrativePhysiology13 160(2) 278-shy‐290

Czapla T E 2002 Facilities plan for the production of endangered fishes to meet statestocking13 plans13 as13 part of the13 Upper13 Colorado13 River Endangered13 Fish RecoveryProgram Upper Colorado River Basin Recovery Implementation Program US Fishand Wildlife Service13 Denver13 9 pp

Davidson W 1997 The effects13 of exercise13 training on teleost fish a review of recentliterature Comput Biochem Physiol 117A67ndash75

Figiel Jr C R 2005 Annual report fiscal year 2004 Willow Beach National13 Fish HatcheryUS Fish and Wildlife13 Service Willow Beach 17 pp

Figiel Jr C R M E Ulibarri G Carmichael J Seals and J N Hanson 2005 Intensive13 fish13 culture of warmwater native fishes at a coldwater fish hatchery Pages 164-shy‐16613 inProceedings of two symposia restoring native fish to the lower Colorado13 River13 interaction13 of native13 and13 non-shy‐native13 fishes July13 13-shy‐1413 1999 Las Vegas Nevada USFish and Wildlife Service Southwest Region Albuquerque New Mexico

Gerking13 S D 1978 Ecology of freshwater fish13 production13 Halstead Press13 New13 York

Gustafson W and Q Bradwisch 2000 Wahweap operation and maintenance -shy‐-shy‐ UtahColorado River Recovery Program FY 2000 annual project report Project No 29cUtah13 Division of Wildlife13 Resources Page AZ 3pp

52

13

Hamman R L 1985 Induced spawning of hatchery-shy‐reared13 razorback sucker ProgressivFish Culturist 47(3) 187-shy‐189

Hanson J N 1996 Annual report fiscal year 1996 Willow Beach National Fish HatcheryUS Fish and Wildlife Service13 Willow Beach 9pp

Irving D S Seversen and M Montagne 2004 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2004 annual project13 report Report No 29b US Fish and13 Wildlife13 Service Vernal 3pp

Jorgensen E H and13 M Jobling 1994 Feeding and13 growth13 of exercised13 and13 unexercised13 juvenile Atlantic salmon in freshwater and performance after transfer to seawaterAquaculture International 2 154-shy‐164

Kaeding L R and D B Osmundson 198913 Colorado13 Squawfish13 and13 razorback sucker grow-shy‐out pond studies as part of conservation measures for the green mountain andRuedi reservoir water sales Final report for agreement number 6-shy‐AA-shy‐60-shy‐00150

Koebele13 B P13 198513 Growth and the size hierarchy effect an experimental assessment ofthree proposed mechanisms activity differences disproportional food acquisition13 pysiological stress Environmental Biology of Fishes 12 181-shy‐188

Kretschmann A E and L L Leslie 2006 Razorback sucker (Xyrauchen texanus) status13 reproduction and recruitment in Senator Wash Reservoir CA Final Report13 to USBurea of Reclamation Cooperative Agreement No 00-shy‐FG-shy‐34-shy‐ 0009 p 32 ArizonaGame and Fish Department Phoenix

Marsh13 P13 C13 1987a13 Digestive tract13 contents13 of adult razorback suckers13 in Lake13 MohaveArizona-shy‐Nevada Transactions of the American Fisheries Society 116117-shy‐119

Marsh P C 1987b Native fishes at Buenos Aires National Wildlife Refuge and ArizonaState University Research Park Arizona opportunities for management researchand public13 education13 on13 endangered species13 Proceedings of the Desert13 FishesCouncil 1967-shy‐78

Marsh P C 1994 Rearing native Colorado River fishes in golf course ponds Arizona StateUniversity Tempe 22 + pages

Marsh13 P13 C13 200013 Fish population13 status and evaluation13 in13 the Cibola13 High Levee PondFinal report agreement number 99-shy‐FG-shy‐30-shy‐00051 US Bureau of ReclamationBoulder City13 Nevada13 20 pages

Marsh P C and C A Pacey 1998 Growth of wild adult razorback suckers13 in Lake13 Mohave13 Arizona-shy‐Nevada13 Final report13 US Bureau of Reclamation Boulder City Nevada 25pages + appendices

53

13

Marsh P C B R Kesner and C A Pacey 2005 Repatriation as s management strategy13 to13 conserve a critically13 imperiled fish species North American Journal of FisheriesManagement 25 547-shy‐556

Marsh P C and C A Pacey 2005 Immiscibility of native and non-shy‐native13 fishes Pages 59-shy‐63 inMJ13 Brouder13 CL13 Springer13 and CS13 Leon13 editors13 Proceedings of two13 symposia Restoring native fish to the lower Colorado River interactions of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 NV and13 Restoring natural13 function within a modified riverine environment the lower Colorado River13 July13 8-shy‐913 1998 Las Vegas NV US Fish and13 Wildlife13 Service Southwest Region AlbuquerqueNew Mexico

Marsh13 P13 C13 and J13 E Brooks13 198913 Predation13 by ictalurid catfishes as a deterrent13 toreestablishment of hatchery-shy‐reared13 razorback sucker The Southwestern Naturalist34188-shy‐195

Matthews R A 2005 Ichthyopthirus multifiliis Fouquet and Ichthyopthirosis infreshwater13 teleosts13 Pages13 159-shy‐218 in Advances in Parasitology volume 59 J RBaker R Muller D Rollinson (eds) Academic Press

McCarthy13 M S and W L Minckley 1987 Age estimation for razorback sucker (PiscesCatostomidae) from13 Lake Mohave Arizona and Nevada Journal of the Arizona-shy‐Nevada Academy of Science 2187-shy‐97

Minckley13 W L13 198313 Status of the razorback13 sucker13 Xyrauchen texanus (Abbot)13 in13 thelower Colorado River basin13 The Southwestern13 Naturalist13 28(2) 165-shy‐187

Minckley13 W L13 199113 Native fished of the Grand Canyon13 region an obituary13 Pages 124-shy‐177 in Colorado River ecology and dam13 management National Academy PressWashington13 DC

Minckley13 C13 O and M LaBarbara13 199913 Report13 on13 native fish grow-shy‐out facilities13 at Cibolaand Imperial National Wildlife Refuges 1993-shy‐199513 US Fish and13 Wildlife Service13 Parker Fishery Resources Office Parker Arizona

Modde13 T13 199613 Juvenile razorback sucker (Xyrauchen texanus) in a managed wetlandadjacent13 to the Green13 River13 Great13 Basin13 Naturalist13 56375-shy‐376

Modde T KP Burnham and E J Wick 1996 Population status of the razorback sucker13 inthe middle Green River (USA) Conservation13 biology 10 110-shy‐119

Modde13 T13 and G13 B Haines13 200513 Survival13 and growth of stocked razorback13 sucker andbonytail in multiple floodplain wetlands of the middle Green River under resetconditions13 Final report prepared for Upper Colorado13 River13 Basin RecoveryImplimentation Program US Fish and Wildlife Service Vernal 66 pp

54

13

Modde T Z H Bowen and D C Kitcheyan 2005 Spatial and temporal use of a spawning13 site in the middle Green River by wild hatchery-shy‐reared13 razorback suckers13 Transactions of the American Fisheries Society 134937-shy‐944

Mueller13 G13 199213 The native fish work13 group13 -shy‐ a multiagency endeavor to improve thestatus of the razorback sucker in Lake Mohave AZ-shy‐NV13 Proceedings of the DesertFishes Council 2369

Mueller G 1995 A program13 for maintaining the razorback sucker in Lake MohaveAmerican Fisheries Society Symposium 15127-shy‐135

Mueller13 G13 200613 Ecology of the bonytail13 and razorback13 sucker and the role of offchannelhabitats13 in their13 recovery Scientific13 investigations13 report 2006-shy‐5065 US GeologicalSurvey13 Denver

Mueller G and E Wick 1998 Testing of golf course ponds at Page Arizona for suitability13 as grow-shy‐out facility for razorback sucker using surplus fish from13 Ouray NationalFish Hatchery National Park Service US Fish and13 Wildlife13 Service and UtahDivision of Wildlife13 Resources 28 pages

Mueller13 G13 and T13 Burke13 200513 Survival13 of young13 razorback13 sucker (Xyrauchen texanus) inrelation to13 stocking rates13 (fishha)13 and13 in the presence13 or absence13 of predatorcommunities in Lake Mohave Arizona-shy‐Nevada13 Pages13 155-shy‐16313 in Proceedings of two13 symposia restoring native fish to the lower Colorado River interaction13 of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 Nevada US Fish and Wildlife13 Service Southwest Region Albuquerque New Mexico

Mueller13 G13 J13 Carpenter13 and P13 C13 Marsh13 200413 Cibola13 High Levee Pond annual report 2004US Geological Survey Fort Collins13 Science Center13 Colorado13 and Arizona StateUniversity Tempe 23 pages

Nesler T P K Christopherson J M Hudson C W McAda F Pfeifer and T E Czapla 2003An integrated stocking plan for razorback sucker bonytail and Colorado13 pikeminnow for the Upper Colorado River Endangered Fish Recovery ProgramAddendum13 to State Stocking Plans Upper Colorado River Basin Recovery13 Implementation Program 12 pp

Papoulias13 D and W13 L Minckley13 1992 Effects13 of foo availability13 on survival and growth13 of larval razorback suckers13 in ponds Transactions of the American Fisheries Society121340-shy‐355

Paukert13 C P D L Ward13 P J Sponholtz13 and K13 D Hilwig13 Effects13 of repeated hoopnetting13 on bonytail chub13 Journal of Freshwater13 Ecology13 20(4) 649-shy‐653

Pfeifer F M13 C Baker13 and M13 Montagne13 199913 Propagation13 facilities13 in the13 Grand Valley13 (24 Road13 Hatchery13 Horsethief13 Ponds and13 grow-shy‐out ponds) for captive rearing of

55

13

endangered13 fishes for the13 Upper Colorado13 River Basin13 Colorado13 River Recovery13 Program FY 99 annual project report Project No 29a13 US Fish and Wildlife Service13 Grand13 Junction13 5pp

Pfeifer F S Seversen and M Montagne 2003 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2003 annual reportProject No 29b13 US Fish and Wildlife13 Service Vernal13 4pp

Rabago-shy‐Castro J L Sanchez13 J G Perez-shy‐Castaneda R and13 Gonzalez-shy‐Gonzlez A 2006Effects of the prophylactic use of Romet-shy‐3013 and13 copper13 sulfate13 on growth13 condition13 and feeding13 indicies in13 channel13 catfish (Ictalurus punctatus) Aquaculture 253 343-shy‐349

Reinitz GL L E Orme and F N Hitzel 1979 Variations of body compositio and growth13 among strains of rainbow trout Transactions of the American Fisheries Society 108204-shy‐207

Ruppert13 J13 B P B Holden13 and P D Abate 1999 Age estimation and growth of razorbacksucker13 Xyrauchen texanus in Lake13 Mead Nevada Proceedings13 of the Desert FishesCouncil 3040

Schnoor K D and J Logan 2002 Operation and maintenance of JW Mumma nativeaquatic13 species restoration facility Colorado Colorado River Recovery Program FY2002 annual project report13 Project No 29d Colorado13 Division of Wildlife Alamosa3pp

Salisbury13 L13 1998 Factors13 affecting razorback13 sucker growth13 in Lake13 Mohave backwaters13 MS Thesis13 Unviersity13 of Nevada13 Las13 Vegas

Schooley J13 D13 and P C13 Marsh13 2007 Stocking of endangerdd13 razorback13 suckers13 in thelower Colorado River Basin13 over three decades 1974-shy‐2004 North American Journalof Fisheries Management 27 43-shy‐51

Severson S H H M Tyus and G B Haines 1992 An evaluation of feeds for raisingrazorback sucker Xyrauchen texanus Journal of Applied Aquaculture 155-shy‐65

Toney D P 1974 Observations13 on the13 propagation13 and13 rearing13 of two13 endangered species13 in a hatchery environment Proceedings of the Annual Conference of the Western13 Association of State Game and Fish Commissions 54 252-shy‐259

Tyus H M13 1998 Razorback sucker13 (Xyrauchen texanus) recovery plan13 University13 ofColorado Center for Limnology Boulder13 76 pages

Tyus H M13 and13 S H Severson 1990 Growth13 and13 survival of larval razorback suckers fedfive formulated diets The Progressive Fish Culturist 52197-shy‐200

56

13

Ulibarri M E 2003 Annual report fiscal year 2001 Dexter National Fish Hatchery13 andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 26 pages

Ulibarri M E 2003 Annual report fiscal year 2002 Dexter National Fish Hatchery andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 59 pages

USBR 2006 Lower13 Colorado13 River Multi-shy‐Species Conservation Program final fishaugmentation plan Boulder City 19 pp

USFWS 2002 Razorback sucker (Xyraouchen texanus) recovery goals Amendment andsupplement to the Razorback Sucker Recovery Plan13 US Fish and Wildlife Service13 Region 6 Denver13 Colorado

USFWS 1999 Annual report 1999 Ouray National Fish Hatchery Vernal 25pp

USFWS 2004 Management plan for the big-shy‐river13 fishes of the13 lower13 Colorado13 river basinamendment and supplement to the bonytail humpback chub Coloradopikeminnow and razorback sucker recovery plans

USFWS13 2005 Station13 profile13 of the13 Dexter13 National Fish Hatchery13 and Technology CenterUS Fish and Wildlife13 Service Dexter

Valdez R A P G Mangan R Smith and B Nilson 1982 Upper Colorado River fisheriesinvestigations13 inW H Miller J J Valentine D L Archer H M Tyus R A Valdezand L13 Kaeding13 editors13 Colorado River Fishery13 Project13 Part 2 Field13 investigations13 US Bureau of Reclamation Salt Lake City Utah

WBNFH 2004 Culture methods of the endangered razorback sucker Xyrauchen texanusUS Fish and Wildlife13 Service Willow Beach National Fish Hatchery13 8 pp

Ward D 2008 Effects of disease treatments on growth of razorback sucker ReportSubmitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 Inpartial fulfillment of work task C10 agreement number 06FG30039

Ward13 D13 M Childs and W Persons 2007 Factors13 affecting13 growth13 of razorback sucker13 (Xyrauchen texanus) in captivity Literature review and knowledge assessmentReport Submitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 In partial fulfillment of work task C10 agreement number 06FG30039

57

Appendices

Appendix 1 Survey Questions Survey of Razorback Sucker Culture in the

Southwestern United States

The enclosed survey is being distributed by the Arizona Game and Fish Department to razorback sucker culture facilities throughout

the Southwestern United States The purpose of this survey is to consolidate information regarding culture of this species so that

appropriate facility improvements can be considered for Bubbling Ponds Hatchery in Arizona Specifically we wish to increase

growth rate and production efficiency at the hatchery Information gathered in this survey will be summarized in a final report to US

Bureau of Reclamation in Boulder City NV and disseminated to all facilities that participate in the survey A workshop to discuss

the findings of this study as well as to share general information concerning razorback sucker culture will be organized by the

Arizona Game and Fish Department at the conclusion of this study and all participants will be invited

Thank you for taking the time to fill out this survey Please contact Mike Childs if you have questions or would like to discuss the

survey

Mike Childs

mchildssedonanet

(928) 639-1346

(928) 634-1279

Facility_____________________________________ Date___________________

Contact Phone _____________________________

ContactPerson_______________________________

Contact Email _______________________________

1 Water quality ranges at this culture facility

Season

Spring (Mar-May) Summer (Jun-Aug) Fall (Sept-Nov) Winter (Dec-Feb)

Temperature (C)

PH

DO (mgL)

PO4 (mgL)

TDS (mgL)

Hardness (mgL)

CaCO3

Pathogens

37

13

Executive13 SummaryThe few remaining razorback sucker populations are sustained by captive13 rearing13

and stocking programs and the survival13 of stocked suckers in13 the wild is largely13 associated

with size at stocking Experimental studies at Bubbling Ponds Fish Hatchery AZ have been

ongoing for the13 last 5 years13 to13 understand13 factors13 that affect razorback sucker13 growth13 in

captivity13 and to13 identify ways to improve growth rates and maximize size at release This

work13 consists of a literature review an experimental study of disease treatment effects13

and observations of individual13 fish growth in13 ponds under different13 conditions

Literature13 review

A literature review and hatchery13 site visits concluded that13 razorback13 sucker growth

is extremely variable and impacted by many factors including fish size and age sex density

amount of living space quality and quantity of food genetics and temperature13 Culture13

practices for razorback13 suckers vary13 widely13 and include13 differences in rearing13

environments rearing densities feeding regimes and types of feed as well as grading or

sorting practices Calculated growth rates from13 the literature vary widely and range from13

02 ndash 18 mmday with the highest growth rates reported from13 natural or semi-shy‐natural13

pond environments These growth rates indicate that juvenile razorback suckers have a

very hig growth13 potential under ideal rearing conditions13

Growth during disease13 treatments

Formalin copper sulfate potassium13 permanganate and salt are all chemicals

commonly used to treat Ichthyophthirius multifiliis and other disease outbreaks13 in hatchery13

populations of razorback13 sucker13 We exposed juvenile razorback13 suckers to 513 5-shy‐day13

treatments with each chemical to evaluate the effects these chemicals may have on growth

Fish grew an average of 235 mm TL during the 3 month study period No significant

differences in growth were observed among fish treated with any of the chemicals

compared to untreated fish (pgt005) Reductions in growth as a result of repeated chemical

treatments are not likely the cause of differences in growth rates among facilities that raise

razorback suckers Repeated chemical treatments may have other impacts to overall

fitness13 or long-shy‐term13 survival but these effects were not evident in our study

5

13

Pond growth studies

Growth13 studies13 were13 conducted13 at the13 Bubbling Ponds Fish Hatchery from13 2009 to

2011 These studies13 were13 largely13 observational13 because hatchery production requirements

prevented experimental manipulation of dependent variables Our initial13 work13 identified

razorback growth rates in lined ponds at standard fish density as 026 to 028mmday

(789 to 843 mmmonth) Additional13 studies include observations of growth rates in13 lined

and unlined ponds13 fish at different13 densities13 sorting13 practices13 and growth in13 the absence

of the13 ectoparasite13 Ich

Our data13 suggests that13 growth rates at the Bubbling13 Ponds Fish Hatchery are likely

as high as possible given the pond densities required to meet production goals and the Ich-shy‐

infested water that feeds the facility Sorting practices are successful in helping as many

fish as13 possible13 reach13 stocking13 length13 as13 fast as13 possible13 Unlined13 ponds may be able to

grow13 large13 fish at low densities but whatever factors13 allow for that growth13 are13 not able to

overcome high fish density Growth rates were highest following removal of Ich from13 the

Bubbling13 Ponds Spring13 032 mmday (96 mmmonth) but that growth13 rate13 decreased13

again13 as Ich re-shy‐infested13 the13 hatchery

Conclusions

We conclude that under typical hatchery operations (maximizing number of fish

produced)13 the growth13 rate13 of razorback13 suckers is relatively13 consistent at Bubbling13 Ponds

hatchery13 at13 02-shy‐03 mmday (6-shy‐9 mmmonth)13 but is lower than growth13 rates13 at other

facilities (02 ndash 18 mmday Ward et al 2007)13 This growth13 rate13 has13 been13 constant in both13

lined and unlined ponds at all fish densities we were able to measure is temperature

independent13 and13 is likely13 enhanced13 by13 separating13 fast and13 slow-shy‐growing13 fish after the first13

year of growth13 To achieve13 growth13 rates13 substantially13 higher than13 this13 will likely13 require

significant changes in rearing practices that may not be practical in order to13 reach13

numerical production13 goals

Two major changes that might result in higher growth rates are substantially

reducing fish density and modifying the way spring water is delivered to the facility (via

either repeated chemical treatments or enclosed concrete water diversions) to eliminate

Ich from13 the hatchery source water Other potential changes not address by our work

6

13

include13 flow-shy‐training razorbacks much previous literature including MSCP-shy‐funded13 work

on razorback suckers13 suggests13 that fish growing13 in flowing13 water13 will grow faster13 than13 fish

in still water (Jorgensen and Jobling 1994) Furthermore there are a wide variety13 of

potential benefits associated with growing13 fish13 in flowing13 water in addition13 to increased

growth13 rates13 (Davidson13 1997 Castro13 et al 2011)13 Finally given that stocking of smaller

razorbacks13 has13 been13 largely unsuccessful13 perhaps13 BPH goals could be changed from13

producing 12000 fish at 300+ mm per year to a smaller number of very large fish each

year Growing fewer larger fish could potentially be accomplished in the same time frame

as more smaller fish but a better understanding13 of how13 density alters growth rate would

be required to be confident13 of this

7

13

I Literature13 Review

Section13 SummaryThe few remaining razorback sucker populations are sustained by captive rearing and stockingprograms Captive-shy‐reared razorback suckers commonly13 experience13 high predation whenstocked into natural environments This13 creates13 the need to rear fish to larger sizes13 in captivityand to13 find new ways to13 improve growth for captive-shy‐reared fish We reviewed publishedliterature and agency reports for information on factors that affect growth of13 razorback suckerSite visits to13 razorback sucker production facilities and surveys of fish hatchery13 personnel wereconducted to obtain information on current rearing practices Razorback sucker growth is13 extremely13 variable13 and impacted by13 many13 factors including13 fish size13 and age sex densityamount of living13 space quality13 and quantity13 of food genetics and temperature This makesevaluations of individual factors that affect growth difficult Culture13 practices for razorbacksuckers13 vary widely and include differences13 in rearing environments rearing densities feedingregimes and types of feed as well as grading or13 sorting practices The focus at most razorbackrearing facilities is production so the types of data that are collected13 are often insufficient fordetailed13 evaluations of rearing practices on growth Calculated13 growth13 rates from theliterature vary widely and range from 02 ndash 1813 mmday Typically the highest growth13 rates arereported from natural or semi-shy‐natural pond environments These growth rates indicate thatjuvenile razorback suckers have a very high growth potential under ideal rearing conditionsDetailed replicated studies are needed to accurately compare the effects of individual rearingpractices on13 growth These types of studies will ultimately provide both time and cost-shy‐savings13 to production facilities by reducing the time it13 takes for razorback suckers to reach stockingsize improving overall production efficiency

8

13

Introduction

State and federal wildlife management agencies have been rearing razorback

suckers in captivity since the 1970rsquos (Toney 1974 Hamman 1985) to augment declining

natural13 populations Both wild-shy‐caught larvae13 and captive-shy‐bred fish are reared at fish

hatcheries13 and13 grow-shy‐out ponds throughout the13 southwestern13 United13 States13 (reviewed13 in

Mueller 2006) Each facility has unique environmental conditions and different rearing

methods which yield different growth rates Unlike commercial fish species which have

been cultured and studied extensively little published information is available on the

effects of various rearing methods on growth of razorback sucker

Low survival rates13 of stocked13 razorback suckers13 (Brooks13 1986 Marsh13 and13 Brooks13

1989 Marsh13 and13 Pacey13 2005)13 have13 caused13 target sizes for stocking13 to13 steadily13 increase13 in

efforts to reduce predation mortality (Marsh et al 2005 Schooley and Marsh 2007)

Rearing fish to larger sizes comes with increased costs and creates the need to know which

factors13 have the greatest impact on growth rate and how these factors can be controlled to

maximize growth This document compiles and summarizes information on current

captive13 rearing practices13 and associated13 growth13 rates13 for razorback sucker13

We reviewed relevant13 published literature and agency reports on13 razorback13 sucker

to compile background information regarding the effects of environmental factors and

rearing methods on growth A questionnaire was developed (Appendix 1) and sent to

hatchery managers who rear razorback suckers Follow up surveys13 were13 also13 conducted13

by telephone (Appendix 2) Information on rearing densities water quality diseases and

management practices at each facility were recorded Site visits to Bubbling Ponds State

Fish Hatchery13 in Arizona Dexter National Fish Hatchery in New Mexico Grand Valley

Endangered Fish13 Facility13 in Colorado13 Ouray13 National13 Fish13 Hatchery13 in Utah and the Willow

Beach National Fish Hatchery in Arizona were also conducted as part of this knowledge

assessment Telephone interviews were conducted with personnel from13 other locations

that13 produce razorback13 suckers (Uvalde National13 Fish Hatchery13 Hualapai Ponds13 Lake

Mead Fish Hatchery and JW Mumma Fish Hatchery) or facilities that formerly produced

razorback suckers but currently focus on other species (Wahweap Fish Hatchery Achii

Hanyo13 National Fish Hatchery Mora National Fish Hatchery)

9

13

Information from13 all of these sources is summarized to aid future researchers in the

design of more detailed studies on razorback sucker13 growth Understanding the13 factors13

that13 control13 razorback13 sucker growth will13 allow13 expanded fish-shy‐rearing capabilities13 and13 aid13

in reaching management objectives for stocked fish Preservation of genetic resources for

razorback suckers13 depends on captive rearing and stocking programs until permanent

solutions to factors that prevent wild recruitment can be found

Summary13 of Facilities

There are13 over 50 locations13 that have13 been13 used to13 rear13 razorback suckers13 (Table13 1) These

include13 both13 intensive13 culture13 facilities13 with13 raceways13 or circular13 tanks13 as13 well as13

production13 ponds13 golf-shy‐course13 ponds and natural floodplain-shy‐wetlands The majority of

razorback suckers that are stocked come from13 six major production facilities Bubbling

Ponds State13 Fish13 Hatchery13 The Grand13 Valley13 Endangered13 Fish Facility13 and13 Dexter13 Ouray13

Willow13 Beach13 and Uvalde National13 Fish Hatcheries13 Tables 2-shy‐313 outline13 the13 types13 of fish

holding facilities and water quality conditions that exist at each of these main production

locations A brief summary of procedures for rearing razorback suckers at each of these

facilities13 follows

These summaries are based on interviews conducted with hatchery personnel in July 2007 during site visits

This information13 is provided only to give a brief overview of razorback grow-shy‐out procedures Please verify13

accuracy13 of specific information with individual hatchery managers

10

13

Table13 1 List of locations13 that have13 been13 used to13 grow-shy‐out razorback suckers

$$amp ()amp$+ ($ampamp$+( $amp()$+ $amp()amp+(-0(12(342056( )0(-75amp8(95amp( 0$$05(lt==gt( 5amp+(amp4amp(Aamp+amp050+(12(14$6( 5amp+(amp4amp8(B$5+( B7$(lt==lt8()C0C05(lt===8(D0$05(0($(lt==E8(amp2F(0($(lt==E(

GltHI5+(342056J( K0L05(Damp$(12(342056( K0L058(D0M(0L4( N$055(lt==E( FF(-0(12(342056( D05(9$F8(B$5+( -42amp5(amp+($amp(lt==lt( OP0(0+(342056( $+05(B68(D0Q+( N-R(lt==gt( S56(Damp$(12(342056( D05(T05amp$8(N2( B7$(lt==lt8(U5Qamp(0($(lt==H8()C0C05(0($(lt==E8(0$$05(lt==gt8(N-1V-(WXXX( NQ$+0(Damp$(12(342056( NQ$+08(Y0L( N-R(lt==gt( V2M07(12(342056( M058(N2( B7$(lt==lt8(Qamp(amp+(5+M42(lt===( V$$M(042(Damp$(12(342056( 0$M(3Q05(KF(amp(B$5+(RQ058(95amp( 3ampamp(WXXgt( 942(3amp6( D05()5P058(95amp( N-1V-(lt==Z( --+-0+-12-3(4-5 )005(7amp+( 5amp+(amp4amp8(B$5+( Y2+(amp2F8(705amp$(4FFamp4amp( ltgt(5+(7amp+( 5amp+(amp4amp8(B$5+( )C0C05(0($[(WXXX( amp+(7amp+(( 5amp+(amp4amp8(B$5+( )C0C05(0($[(WXXX( B$6F05()amp+( BampC$0amp40(C(B$5+(amp+(ampampamp( )C0C05(0($[(WXXX8(B7$(lt==lt( B$5+(I(W](++amp$($00+(7amp+( 5amp+(T$$068(B$5+( )C0C05(lt===( KP0(5+(7amp+( 5amp+(T$$068(B$5+( )C0C05(0($[(WXXX( 32$amp0(7amp+( 5amp+(T$$068(B$5+( )C0C05(0($[(WXXX( 35020C(505amp(7amp+( 5amp+(amp4amp8(B$5+( )C0C05(lt===8(B7$(lt==lt( 0-6-3+ $620(Famp47$($C(450( $6208(B$C5amp( ^50amp($C(450_(9-N(R00542()5P( 08(95amp( 52(WXXH8(52(WX]( )0($C(450(7amp+( )08(95amp( 0$$05(amp+(V4P(WXX]( 768639 0amp(50(DVR( -2(C(Y4amp8(95amp( 52(WX]( B$(32(O0Q00()amp+( B$(Damp$(V$+$C0(R0C08(D05($6208(B$C5amp( 52(lt===8(amp4P$06(amp+(O55(WXXX8(0$$05(lt==gt( SQ05amp(M$+$C0(amp0F0amp(50( D05(OP0(0+(ampC$M8(D0Q+( N-R(lt==gt( -0amp5(V2( D52(C(`F8(95amp( ^5042Fampamp(amp+(O0$0(lt==gt8(amp4P$06(amp+(O55(WXXX( )1(+ KQ(4Q0( OP0(2Q08(95amp( 0$$05(WXXlt8(0$$05(amp+(5P0(lt==Z( 95amp(aQ0amp$0( OP0(2Q08(95amp( -$56(WXX]( -2(-+0Mamp+05( OP0(2Q08(95amp( -$56(WXX]( `F(BQ0( OP0(2Q08(95amp( 0$$05(WXXlt8(0$$05(amp+(5P0(lt==Z( Kamp+6( OP0(2Q08(D0Q+( -$56(WXX]( D52(B20F020Q0( OP0(2Q08(D0Q+( -$56(WXX]( D52(X($0( OP0(2Q08(D0Q+( Y6(V$05(N-R8(705amp$(4FFamp4amp( V$$M( OP0(2Q08(D0Q+( Y6(V$05(N-R8(705amp$(4FFamp4amp( D0Q+(A( OP0(2Q08(D0Q+( Y6(V$05(N-R8(705amp$(4FFamp4amp( D0Q+(O5Q0( OP0(2Q08(D0Q+( Y6(V$05(N-R8(705amp$(4FFamp4amp( 0+58lt+--457(5 9Q0(50ampampamp( D05(T05amp$8(N2( )C0C05(0($[(lt==E( ampamp(5+0( D05(T05amp$8(N2( )C0C05(0($[(lt==E( 2ampamp(F( D05(T05amp$8(N2( ++0(amp+(3amp0(lt==Z( O0(W=( D05(T05amp$8(N2( N-1V-(WXXX( O0(F( D05(T05amp$8(N2( ++0(amp+(3amp0(lt==Z( S$+(425$06(V2( D05(T05amp$8(N2( ++0(amp+(3amp0(lt==Z8(++0(WXXgt( O00+(7amp+(amp(20(Namp2(amp( D05(T05amp$8(N2( U5Qamp(0($(lt==H8()C0C05(0($(lt==E( =($+ 1$6+(OF(0(75P(GY0$0(75ampJ( O(T08(D0Q+ (52(WXXH( Y5amp++(-0(amp5(B$$00( 9$F8(B$5+( -42amp5(amp+(Oamp(lt==lt( 5MI(7amp+( D05(15Fampamp8(D( -42amp5(amp+(Oamp(lt==lt(

11

13

Table 2 Facilities available at major razorback sucker fish hatcheries

$amp( )$+(-+( 0(1(2$amp3amp(( 4-56+ amp7(8-+1$(9+( lt3-5( 8=$33( 23gt(805(

$amp()amp+(-(012345( 0(0+amp(A(BBCC(05 ampD(ED F CGBH IACCCACCC BJH K$+L(0D

amp$+(M$gt$ O-$+(+($P

B N B

CGBH IACCCACCC BABHC FANCC

BJH

Qamp+-3$+($P F FHC 637134(801amp0$(-(012345( H(L$33gt($O-amp1+(gt33A(

BCCC(05 ampDRK$+L(0D amp$+(M$gt$ M$-3$+($P Qamp+-3$+($P Qamp+-3$+($P

9O-$+amp$

SF S BC SC HC TC

CGI((IGC( HAHCC HSC IBC BCC IC

9O-$+amp$ BC SC 940amp+(amp21amp(8013(-(-02$15( U-ampamp0$3(D+ampPamp(gt$+ Qamp+-3$+($P IS VCC IB

W+Lamp1(+$+amp(0D( E-50D(+ampX+(gt$+( Qamp+-3$+($P JT BCC H K$+L(ED T CGBH(Y(CGH(

lt405(801amp0$(-(012345( J(L$33gt(gt33A(FCC(05( ampD(0D BS CGIBH(Z(CGBH( IC Qamp+-3$+($P NC IBC H Qamp+-3$+($P BJ VCC IC((IH

=$$gt(302(801amp0$(-(012345( 3$+(L$D(Q3+$D( MampX+(gt$+( amp$+(M$gt$ N IAHCC

amp$+(M$gt$ IF IFACCC 9O-$+amp$ FC IC

0$+3(801amp0$(-(012345( B([0(9O-amp1+()33A( IHCC(05 ampD(0D II I

K$+L(0D amp$+(M$gt$ amp$+(M$gt$

NJ B IB

GBH(Y(IGC( FAHCC IACCC

Qamp+-3$+($P Qamp+-3$+($P

IB N

BCC NACCC

12

13

Table13 3 Water13 quality13 ranges13 at each13 culture facility$amp ($)$++) -+$

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Bubbling Ponds State13 fish Hatchery13

Bubbling Ponds Fish Hatchery in Arizona does not maintain razorback sucker

broodstock on site Razorback suckers are received either as juveniles from13 Willow Beach

National Fish Hatchery13 or as13 newly-shy‐hatched larvae from13 Dexter13 National Fish Hatchery

Larval fish are13 typically13 placed13 into13 an unfertilized unlined 0613 acre13 pond13 in the13 spring In

September the pond is harvested by draining the pond and seining All fish that have

reached the target size (300 mm TL) are stocked Fish that are too small to stock are split

up equally between the six remaining grow-shy‐out pond at an13 average13 density13 of about 5000

ndash 7000 fish per pond Fish are fed by hand at approximately 25 body weight split

between morning and evening feedings Fish are either fed a catfish diet made by Rangenreg

13

13

that is enriched with spirulina and krill or razorback sucker diet made by Silvercupreg

depending on availability Fish are monitored visually and by sampling using a cast net

When a large number13 of fish have13 grown to13 the13 target size they13 are13 harvested13 by13 draining

the pond and seining13 Fish are again13 sorted by hand and the largest13 fish are stocked13 Fish

that13 have not13 reached the target13 size are returned to the ponds for further grow-shy‐out13 On13

average it13 takes one to two years for fish to reach the target13 size with fish growing13 an

average of 06 mmday Target numbers for production are 12000 razorback suckers

annually (300 mm TL) The biggest difficulty in rearing razorback suckers at Bubbling

Ponds13 Fish Hatchery13 is protozoan13 parasite13 infestations13 (Ich) and13 associated13 bacterial

infections that come from13 an open spring source that is inhabited by mosquitofish

Dexter National Fish Hatchery13

Dexter National Fish Hatchery maintains four separate razorback sucker13

broodstocks13 These fish are spawned on13 site and larval13 fish are placed directly into 01 acre

ponds at a density13 of about 20000 larvae13 per pond (50 ndash 100 thousand13 per13 acre)13 Ponds

are fertilized with alfalfa13 pellets and superphosphate two weeks prior to receiving13 larvae to

produce13 natural13 feed for larval13 fish13 Ponds are13 fertilized again with alfalfa13 pellets one week

after larvae are introduced13 Fish are fed a catfish starter diet13 (sizes 1-shy‐3) made by Rangenreg

that13 is enhanced with spirulina13 and krill13 and then switched over to the razorback13 diet13 once

they are large enough to eat 1mm13 crumble Fish are fed twice a day by hand four days a

week13 at 25-shy‐60 body weight Feed ration is decreased if excess feed is seen remaining

on the13 pond bottom13 following feedings Fish are not graded or sorted during this grow-shy‐out

period Razorback suckers are harvested in the fall by draining ponds completely Fish are

sorted13 at harvest and13 distributed13 to13 other13 facilities13 for further13 grow-shy‐out depending on13

current size requirements Razorback suckers are on average 100 ndash 200 mm TL after the

first growing13 season13 and13 generally13 take13 1 -shy‐18 months for a majority of the fish to reach

300 mm TL There are 16 different species of fish maintained at Dexter National13 Fish13

Hatchery13 and13 having sufficient pond13 space13 to13 grow out separate13 groups13 of fish is the13

limiting factor for production of razorback suckers at this location

14

13

Grand Valley13 Native13 Fish Facility13

The Grand Valley Native Fish Facility maintains its own brood stock13 in13 eight13 ponds

located at the Horsethief Basin Wildlife Area in Grand Junction Colorado Fish are

spawned13 on site13 and13 larvae13 are13 reared13 indoors in fiberglass13 tanks13 at the13 24-shy‐Road13 Fish13

Hatchery13 in Grand13 Junction The 24-shy‐Road13 Hatchery13 consists of two13 separate13 recirculating13

systems that operate using de-shy‐chlorinated13 city13 water13 and two13 large13 fluidized-shy‐ bed sand

filters13 and13 rotating-shy‐drum13 filters for waste removal Fish are held in 4-shy‐foot (n=78) or 8-shy‐foot

(n=14) diameter fiberglass tanks Larval fish are started on prepared feeds immediately

after swim-shy‐up and fed exclusively razorback feeds made by Silvercupreg Fish are started on

a 0-shy‐250 micron razorback diet for the first 10-shy‐1213 days13 and13 then13 fed with13 gradually13

increasing13 feed sizes based13 on observations of feeding13 (250 ndash 400 micron 1 starter) Feed

sizes are mixed when transitioning to the next larger feed size These razorback diets are

specially sifted by Dr Rick Barrows (USDA13 Hagerman experiment station Idaho)

Razorbacks13 are13 typically eating 1mm13 extruded pellets by the time they are 35 to 4 inches

in length Fish are fed approximately 70 body weight per day initially and then gradually

reduced to 15 body weight by the time they reach the 300 mm TL target size Fish are

fed seven days13 a week using13 12-shy‐hr13 belt feeders It takes13 12-shy‐16 months to grow fish to the

target13 size in13 the hatchery13

Razorback suckers are sorted after three months and culled to about 4000 fish per

family lot Culled fish are stocked into leased grow-shy‐out ponds Stocking densities for

juveniles in these ponds is based on previous13 stocking and harvest13 rates13 and is pond

specific13 Grow-shy‐out ponds are13 harvested13 periodically13 using Fyke13 nets13 or trap13 nets13 and13 fish of

the target size are stocked Disease problems (Ich Lernea) water quality problems (low

DO) and difficulty in removing all of the fish are challenges for grow-shy‐out of razorback

suckers13 in these13 natural ponds13

Fish reared13 in the13 24-shy‐Road facility are sorted again at four to five months of age into

small and large size groups to obtain more uniform13 growth rates Batch estimates of fish

weight are done every month for each tank A group of fish are weighed and counted to

give an average weight for the tank with lengths estimated based on a lengthweight chart13

The biggest difficulties13 for growing13 out razorback suckers13 at the13 24-shy‐Road13 Fish13 Hatchery13 are13

insufficient space and water flow (oxygen) to grow fish to the target size At the Horsethief

15

13

Basin13 Ponds where broodstock13 are reared13 diseases such as Ich are problematic because

water is pumped directly from13 the Colorado River

Ouray13 National Fish Hatchery13

Ouray13 National13 Fish Hatchery maintains its own broodstock and13 spawns13 fish on-shy‐site13

Larvae are transferred from13 indoor hatching tanks to unfertilized 02 acre outdoor ponds

and stocked at densities 10000 ndash 20000 larvae13 per13 pond13 Even13 though13 outdoor13 ponds13 are13

covered with13 bird13 netting13 avian predators13 still get caught in the13 nets13 if they13 can see fish

Ponds are dyed blue13 as the13 fish grow to13 prevent avian predation13 While in the outdoor

ponds13 fish13 are13 fed a slow-shy‐sinking salmon diet made by Silvercupreg twice daily by hand

Amount of feed is based on periodic sample counts Fish are grown until late September at

which time temperatures require that all fish13 other13 than13 adult broodstock13 be13 brought

inside for the winter Ponds are drained completely and fish are sorted by hand Fish that

have reached the target size (300 mm TL) are stocked into the Green and Colorado Rivers

All remaining fish are moved indoors13 and13 held13 in three-shy‐foot (n= 30) or eight-shy‐foot (n=27)

diameter circular tanks On average it takes 12 ndash 18 months to grow fish to the 300 mm TL

at Ouray13 hatchery13

Razorback suckers are held during the winter in a recirculating system13 that

operates13 using13 two13 large13 fluidized-shy‐bed sand filters and a rotating-shy‐drum13 filter for solids

removal Fish are fed the Silvercupreg razorback diet using belt feeders There is currently

capacity13 to13 hold13 only13 20000 200-shy‐300 mm TL fish inside the facility and any extra fish13 are13

stocked13 into13 floodplain-shy‐wetlands or used for research purposes13 Ouray no longer leases

any private grow-shy‐out ponds Grow-shy‐out ponds were troublesome due to poor water quality

harvesting13 difficulties13 and13 non-shy‐native13 fish introductions13 The biggest difficulty13 for

production13 of razorback13 suckers at the Ouray13 National13 Fish13 Hatchery13 is space13 during13 the

winter to maintain large numbers of fish and high iron and manganese in the well water

that must be filtered out prior to use

16

13

Willow Beach National Fish Hatchery13

Willow13 Beach National13 Fish Hatchery receives wild-shy‐caught larvae from13 Lake

Mohave Larvae are treated for diseases with formalin and malachite green and placed in

45 ten-shy‐gallon13 flow-shy‐through aquaria13 Recirculated13 solar heated water13 22-shy‐25deg C is used to13

allow production of warm13 water fish at this traditionally cold water facility (Figiel 2003

Figiel et al 2005) Fish are fed brine shrimp nauplii to satiation every hour and after 14

days small amounts of specialized larval fish diet (Encapsulon13 Cyclopeeze13 spirulina13 and

artificial plankton) are introduced After 30-shy‐6013 days13 fish are13 transferred13 to13 six13 32-shy‐gallon13

fiberglass troughs at densities of 1000 to 1500 fish per tank and then a month later moved

outside13 to13 eight recirculating13 raceways that use a combination of well water and solar-shy‐

heated water to maintain temperatures of 22 ndash 25deg C during the summer months

When13 in13 the outside raceways13 fish are fed the razorback13 diet13 using13 belt13 feeders and

fed by13 hand13 at 10 -shy‐ 70 body13 weight per13 day Feed amount is adjusted based on sample

counts according to a feed conversion program13 developed for razorback suckers by Willow

Beach Hatchery personnel This program13 uses length and number-shy‐per-shy‐pound generated

from13 several years of razorback growth data (Figure13 1) Fish are13 sorted13 opportunistically13

and are not handled during the summer months when water temperatures are above 20degC

In 2004 the target size for stocking was 325 mm TL or greater (WBNFH 2004) with a

target13 of producing13 6000 fish per year Reaching this13 target size usually13 takes13 two13 growing13

seasons13 The biggest difficulty13 in rearing13 razorback suckers13 at Willow Beach13 National Fish

Hatchery13 is insufficient space13 to13 grow fish to13 increased13 target sizes (400-shy‐500 mm TL)

Uvalde13 National Fish Hatchery13

Uvalde13 National Fish Hatchery13 in Texas13 receives 35000 ndash 60000 razorback sucker13

fry annually in MarchApril from13 Dexter National Fish Hatchery The fry are acclimated in

bags submerged in the pond for a minimum13 of one hour and released into13 a 1 acre13 fertilized13

pond where they are reared for the remainder of the summer Fingerlings are fed a starter

razorback diet when they reach approximately 50 mm TL In AprilMay the previous year

class of razorbacks are captured from13 their over-shy‐wintering pond enumerated graded and

split into13 one-shy‐acre grow-shy‐out ponds Approximately 4000 ndash 5000 fish will be13 placed13 in each13

one acre pond for summer grow-shy‐out Fish are reared for approximately 150 days (May ndash

17

13

Oct) and fed the Bozeman razorback diet two times a day five days a week at 15 ndash 30

body weight per day based on average water temperature

Figure 1 Relationship between length and number of fish per pound

In general13 juvenile razorback13 suckers (received as fry13 during13 the previous spring)13

reach the target size of 300 mm TL in approximately 6 months In 20062007 Uvalde

produced 6000 razorback suckers 300 mm TL for introduction into the San Juan River

Starting13 in 2008 Uvalde NFH will be producing13 and distributing13 12000-shy‐ 300 mm TL

razorbacks for stocking into the San Juan River Predation from13 migrating cormorants has

occurred but timing of harvest and over wintering protection methods such as covering

ponds with netting or placing fish indoors helps to minimize losses during the cormorant

migration (November to March) Uvalde has experienced razorback mortalities because of

bacterial problems but these are usually resolved through the use of oxytetracyline

medicated feed

Overview13 of Differences in Culture Methods

Several differences were noted when conducting surveys at each of the five main

production facilities for razorback sucker (See Appendix 3) These differences include

different stocking13 and13 rearing13 densities13 (Table13 4-shy‐5) various feeding regimes and type of

18

13

lt=amp

feeds (Table 7) as well as differences in grading or sorting practices Some of these

differences are13 related13 to13 whether13 or not razorback suckers13 are13 being13 reared13 in extensive-shy‐

culture13 facilities13 (ponds) or intensive-shy‐culture13 settings13 (raceways13 o tanks)13 Some13 practices13

are unique to a single facility13 or a couple of facilities (Table 6)13 Managers at each facility13

were asked to identify the biggest13 difficulty or constraint13 that13 they experience when13

growing-shy‐out juvenile13 razorback suckers13 at their13 respective13 location13 Space constraints13

water quality and disease problems were the main factors limiting production of razorback

suckers13 at these13 facilities13 (Table13 8) Calculated or reported growth rates from13 the literature

vary widely (Table 9) and range from13 02 to 18 mmday These growth rates indicate that

juvenile razorback suckers have a very high growth potential under optimal rearing

conditions13

Table13 4 Stocking13 densities13 for larvae13 and13 fry in ponds

$amp( )(+amp-( 01-2(3(4amp56( 4amp56(+amp-( 01-2782-( $amp () + --amp +amp0amp)+amp 12-3amp ( )+amp0amp+amp --amp +amp0amp)+amp 42556789amp8 ( +amp0ampgt+amp 3amp +amp0amp+amp A-BC-Damp (E + 3amp )+ F-6ltamp ) G+ 3amp G+

Table13 5 Rearing13 densities13 at intensive13 culture13 facilities13

$amp( )amp+(($-( $0( 12(3$+( 40((amp05( 67((amp05( 8$9(407$( $amp amp())amp++-$amp 0 1 0amp2amp1amp 3amp2amp4 0544

6amp())amp++-$amp 610 021 4amp2amp47amp 3amp2amp77amp 058 9$amplt+)amp 4amp())amp++-$amp 00 1 7amp2amp77amp 851amp2amp0amp 05

6amp())amp++-$amp 610 77amp2amp1amp 0amp2amp1amp 053

19

13

Table13 6 Rearing13 practices13 that are13 unique to13 specific rearing13 facilities13 $$amp( )$+-(amp$-(0(1-amp2034( $amp()amp+( -0$(12(33+(amp(amp134$53+(amp$amp3+(6amp+(

723(843(1$8(422(6amp+(42amp(4(423(19$43( 343( lt34$53(6amp+(6(4($03(amp4+94amp(842($1$1(63$$34(amp+(63626243( =amp+(gtamp94ampA( B3(1(1$+53+C3+(amp+(1$43(1(3D0$(1(amp443(amp+(amp443( 734231(amp( B3(1(193(44(1(34amp(amp(+49E(6amp+( -E3(F3+( G3amp(1(12(amp(H3(13$(4ampE(C(IJK($$amp( A( L43(+A3(4(6303amp4(63+4ampM(66$3D3amp4$(34amp(amp(6amp+(C((4amp3( L$$8(392(

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Table13 7 Types of feed used at razorback sucker13 hatcheries13 $amp ()amp+-amp0- $$)1amp23 45-amp)-$5)1amp23 $amp()amp+( -amp$amp+(amp+( -amp012$3+(amp+4(amp5215$(0+( 65ampamp7(85209(+2($1(87((15315lt=(+2(

+amp+amp(amp(55$5$2gt( 21( Aamp+(amp+( )amp+(012$3+(B29(5$05$95($$2(5amp+(

199524(amp5215$(0+( 65ampamp7(85209(+2($1(87(15315lt=(+2(amplt( 29gt(51($51(amp9(2(25=(C(DD(0+(

E15amp+(Famplt2amp( G1$5(lt1lt$51(25amp=( HIJKH(Dlt1amp(15315lt=(+2(I(C2(CH(+5gt( )11$gt($511(02+(15315lt=(+2(

$1(87(15315lt=(+2(D5$$(3(lt5$$gt(02+(gt( 6lt=(511B(

L15gt( G1$5(lt1lt$51(25amp=(Aamp+( amp+(

HIJKH(Dlt1amp(15315lt=(+2(I(C2(CH(+5gt( )11$gt($511(02+(15315lt=(+2(

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M$$B(5lt9(-5$+( NO515(G1$5(219( L2+1(15ltB5gt(Aamp+(5amp+( amp$amp+(amp+(

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$1(87(15315lt=(+2($1(87(15315lt=(+2( $1(87(15315lt=(+2(

Table 8 Factors limiting production at major razorback sucker facilities

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Eamp41(420141(464(1A1($$(lt6(4((2C+(amp+1( 803(3amp41amp4(1$4+(4(541(A$4B(amp+(+$C+(7Bamp(

E$$5(36( 803(3amp41amp4F(15amp(lt6(4(amp31amp$B($11(gt( 1$4(amp(ampltlt3amp4(03(amp(44amp(lt1(amp5(lt6(

GC$+( 8221(420(3amp(4(6691A1amp(051((4(410$(+(4( 661(1amp+541(020amp(4(=0(0amp+(3$F(

20

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Table9Reportedandcalculatedgrowthratesfromtheliterature

Calculatedgrow

thratesbasedon

informationprovidedinliterature

aApproximationsofmaximum

grow

thpotential(basedon

average13 maximum

sizesiffishreportedatharvest

21

13

General Information on Factors that Affect Fish Growth

Growth in fish is extremely variable and is impacted by many different

physiological and environmental factors Growth rates are known to change with size and

age sex season activity level density amount13 of living space quality and quantity of food

genetics and temperature (Brett 1979) Growth experiments conducted at different times

of year can result in growth rates that are not comparable As fish become larger their

physiological13 potential to grow decreases making determination of growth rate dependent

on the size of the starting fish and the length of the experiment (Busacker et al 1990)

Genetic factors also have great potential to influence growth rate Some species have

strains13 and13 races13 that display vastly different growth potentials (Reinitz et al 1979) All of

these factors combine to make assessment of the individual factors controlling fish growth

difficult13

Water temperature is probably the most important variable affecting growth rate13

All of the basic functions that affect growth such as feeding digestion and metabolism are

temperature-shy‐dependent13 Growth13 is inseparably13 tied13 to13 bioenergetics13 and13 therefore13 also13

tightly tied to temperature When temperatures are below optimum daily temperature

fluctuations can stimulate growth Photoperiod is also commonly linked to water

temperature and can influence growth rates in fish (reviewed in Brett 1979)

Fish density13 is known to13 affect growth13 and13 can alter13 growth13 rates13 in several ways13

Fish that exhibit strong territorial behaviors13 or natural schooling tendencies13 will

experience reduced growth if densities are too high or too low (Brett 1979) Dominance

hierarchies where some fish feed more aggressively than others can also lead to high

variability13 in growth13 rates13 (Koebele13 1985) Crowded13 conditions13 also13 cause physical

interference13 between13 fish and13 poor water13 quality13 which13 reduces13 growth13 (Busacker13 et al13

1990) The effects of fish numbers space and feeding opportunity are frequently correlated13

and often13 difficult13 to distinguish (Brett13 1979)13

It is impossible to study the effects of environmental factors on growth without also

evaluating feed rations (Brett 1979) Amount of food quality of the diet particle size

number of feedings per day and time of feeding have all been shown to affect growth

(Busacker et al 1990) In controlled laboratory studies food is usually fed ad libitum13

22

13

(constantly available) and other variables are altered to assess impacts of environmental

factors13 on growth13 These studies13 are13 usually13 conducted13 in tanks13 or raceways13 because13

researchers must verify that food is constantly available to the fish which is difficult to do

in large pond environments where the fish and the bottom13 are often not visible (Busacker13

et al13 1990)

Specific Information13 o Razorback13 Sucker13 Growth

Variable13 growth

Growth in razorback suckers is naturally highly variable and may be a function of

their evolutionary history (USFWS13 2002)13 Minckley (1983) speculated that13 wide size

variation in a single cohort of razorback suckers may be adaptive with fast-shy‐growing13 fish

that13 reproduce at a young13 age surviving13 better in13 high discharge years and slow-shy‐growing13

smaller fish surviving better during drought periods This highly variable growth rate

makes rearing razorback suckers in a production setting difficult because fish from13 a single

cohort do not reach the target stocking size simultaneously One of the major tasks for

aquaculture is to maximize both individual growth and total production13 (Gerking13 1978)13

This becomes more difficult when the species being cultured exhibits highly variable

growth13 rates13 because of genetic influences as is the case with razorback13 suckers13

Razorback13 sucker growth13 is typically very13 rapid13 during13 the first13 year of life13 and then13

declines with age First year growth can be as low as 50 mm and as high as 350 mm (Valdez

et al13 1982 Minckley13 1983 Mueller13 1995) Razorback sucker13 grow rapidly13 for

approximately the first five or six years of life and then growth slows13 (McCarthy13 and13

Minckely 198713 Tyus 199813 Minckley et13 al 1991)13 Growth of older individuals in13 extant13 wild

populations is very13 low (Minckley 198313 Tyus 198813 Modde13 et al 1996)13 Wild growth13 rates

for mature adult fish in Lake Mohave based on PIT tag recaptures were often too small to

be accurately measured for both males and females over the time period of 1987-shy‐199713

(Marsh and Pacey 1998) This information suggest it will take substantially longer to rear

fish to13 increasingly13 larger13 stocking13 sizes (40013 ndash 500 mm TL) than it did to reach the target

size of 300 mm TL

Growth in ponds

23

13

One of the main strategies for maintaining genetic refugia and self-shy‐sustaining13

populations of razorback13 sucker in the lower Colorado13 River basin13 is to rear razorback13

sucker13 larvae13 in production13 ponds until they13 are13 a suitable13 size for stocking13 (USFWS13 2004)

Pond culture has proven useful to promote rapid growth of juvenile razorback suckers

(Kaeding and Osmundson 1989) Marsh (1994) reported that growth rates of razorback

suckers13 reared13 in golf-shy‐course13 ponds exceeded13 the13 best growth13 rates13 obtained13 under

intensive13 culture13 conditions13 at federal hatcheries13 especially13 during the13 first several years13

of life Growth rates in these semi-shy‐natural ponds are also comparable to estimated growth

rates13 of juvenile13 wild13 fish (McCarthy13 and13 Minckley13 1987) Modde13 and13 Haines13 (2005)

reported13 the13 greatest growth13 rates13 in the13 largest and13 deepest floodplains13 with13 the13 greatest

amount of submergent vegetation but excellent growth and survival of fish in a grow-shy‐out

pond is of little value if there is not an efficient way to collect the fish from13 the pond

(Kaeding and Osmundson 1989)

Temperature13

Bulkley and Pimentel (1983) used shuttle boxes in the laboratory to determine a

temperature preference13 for razorback suckers13 of 23-shy‐24degC13 In13 their13 studies13 razorback

suckers were found to avoid temperatures below 118 degC or above 286 degC Razorback

suckers at Bubbling Ponds Hatchery are more active in the spring and feed better as

photoperiod increases even prior to water temperatures rising (Frank Agygos personal

communication) Table 3 briefly summarizes water temperature data from13 each facility

Detailed seasonal water temperature profiles are not currently available for many

razorback grow-shy‐out sites13

Density13

Extensive studies have been conducted on commercially important species to

evaluate stocking densities and feeding rates that maximize production For these species

controlled experiments under laboratory conditions have established relationships

between temperature density and feed ration on growth (Brett 1979) but this information

is sporadic13 or non-shy‐existent for razorback suckers13 (Bays13 et al13 2005) Fish culturists13 with13

24

13

experience13 rearing13 razorback suckers13 typically13 have13 target stocking13 densities13 that13 they use

(Tables13 4 -shy‐ 5) These stocking densities have largely been determined over time by trial

and error These approximate stocking densities provide a good starting point for more

controlled13 types13 of replicated13 pond studies13

Feed ration

Razorback13 suckers are currently13 being13 fed a wide variety13 of prepared diets (Table 7)

that range from13 a slow-shy‐sinking salmon feed manufactured by Silver Cupreg to a spirulina

and krill-shy‐enhanced catfish feed made by Rangenreg Most locations are feeding 20 ndash 50

body13 weight per13 day13 Methods13 for culture13 of razorback sucker13 larvae13 in intensive13 settings13 at

fish hatcheries are well documented (Figiel 2005) and various larval fish diets have been

evaluated13 (Tyus and13 Severson 1990 Severson et al13 1992) but no standardized13 procedures

are used for feeding13 larval13 fish in13 intensive settings13

Razorback sucker larvae are also effectively reared in pond environments using

natural foods supplemented with larval fish diets and survival is high when no predators

are present13 (Mueller 2006)13 Growth rates for larval13 and early juvenile razorback13 suckers

may increase with pond fertilization Diet and physiological studies on wild razorback

suckers indicate that they feed on plankton as well as benthic organisms during their entire

life (Marsh 1987) Artificially fertilizing ponds may greatly increase production capacity

and growth rates for razorback13 sucker (Papoulias and Minckley13 1992) and warrants

further13 investigation13

Handling stress

Handling stress13 has13 been shown to13 influence growth13 rates13 Paukert13 et al (2005)

found that growth of bonytail chub was reduced by 26when compared with controls

after being13 repeatedly13 captured and handled in13 hoop13 nets13 Handling13 effects are likely13 to be

similar for razorback suckers that are repeatedly13 captured and sorted in13 a hatchery13 setting13

Razorback suckers that are handled at Willow Beach National Fish Hatchery will commonly

not eat for two weeks after handling (John Scott personal communication) This creates a

difficult situation13 for production13 facilities because13 fish13 need to be sorted to ensure13 large13

25

13

aggressive fish do not interfere with growth of smaller individuals but frequent handling

and sorting13 causes stress related reductions in13 growth13

Measuring Growth in Captive Fish

Weight is the traditional measure used to estimate growth or production in

aquaculture settings13 Groups of fish are typically13 weighed and an average individual13 weight13

is computed (Busacker et al 1990) Although this method is often logistically the easiest it

may not be the most informative for species with highly variable growth rates like

razorback suckers especially when target lengths must be reached before fish can be

stocked Weight can also be highly influenced by things like stomach fullness or

development of gonads (Busacker et al 1990) Condition factor or relative weight can also

be used to assess growth of fish but these tools may be more robust predictors of fecundity

than of growth (Anderson and Neuman 1996) For some species sexes need to be

distinguished because males and females may differ in morphology (Anderson and

Neumann 1996) Mueller (2006) analyzed growth rates based on PIT tag recaptures of 86

razorback suckers13 in High13 Levee Pond13 and13 found13 that differences13 in growth13 do not appear13

to occur until fish are over 450 mm TL at which time growth rate in males slows while

females continue to grow at a slightly higher rate This would indicate that sex may not be

an important factor to consider when examining growth rates unless the target grow-shy‐out

size is above 450 mm TL

The best measures of growth are often determined from13 the length and weight of

individuals rather than from13 groups of fish (Anderson and Nuemannn 1996) because

individual growth rates give better estimates of confidence and variance (Busacker et13 al

1990) Length frequency analysis or recapture of previously marked individuals of a known

size is likely to yield the most useful information for razorback sucker growth The success

of any of these methods depends on proper sampling procedures that are representative of

the population as a whole (Busacker et al 1990) Sampling methods that are known to be

size-shy‐biased such as trammel nets (Mueller et al 2004) or cast nets should not be used when

trying to measure growth rates13

26

13

Conclusions

For razorback sucker survival is largely associated with stocking size Additional

focused13 research13 is therefore13 needed to13 identify13 ways13 to13 increase13 growth13 rates13 of captive-shy‐

reared13 razorback sucker Growth13 rate13 in fish is controlled13 by many factors including fish

size and age temperature density and feed ration which can all be highly correlated

Growth of razorback suckers is also inherently variable which makes the task of identifying

the key factors that13 affect13 growth in13 captivity even more difficult The focus at most

razorback rearing facilities13 is production so the13 types13 of data that are13 collected13 are13 often

insufficient for detailed13 evaluations13 of individual rearing13 practices13 on growth13 Surveys of

existing13 razorback sucker13 rearing facilities indicate that culture methods vary widely and

the types of growth data13 that13 are collected are not13 standardized13 Replicated studies with

detailed information on rearing location water temperature initial stocking size stocking

density and the sizes of all fish at harvest are needed in order to compare the effects of

individual rearing practices on growth This type of research will ultimately provide both

time and cost-shy‐savings to production facilities by reducing the amount of time necessary13 for

razorback sucker to reach stocking size improving overall production efficiency

Optimum13 rearing densities for razorback sucker larvae and juveniles remain to be

determined Current stocking densities will be very useful as starting point for more

detailed studies and although optimum13 rearing densities are likely to be site-shy‐specific13

replicated studies on density will provide a valuable reference for hatchery managers

Frequency13 of sorting is another13 area that needs13 further13 research Frequent

handling13 and13 sorting13 can13 cause13 stress-shy‐related13 reductions13 in growth but not sorting can

create dominance hierarchies that further reduce growth rates of subordinate individuals

The effects13 of sorting13 on overall fish growth13 in both13 pond and13 intensive13 culture13

environments warrant further investigation Research techniques for these types of

experiments are well understood and typically utilize a matrix of replicate ponds per

variable (Bays et al 2005) In every case accurate and complete records of sampling

procedures and data collection are needed in order to interpret data and make inferences

about13 growth rates (Busacker et13 al 1990)13

27

13

Additional research is also needed to evaluate long-shy‐term13 survival of stocked fish

reared in ponds compared to fish13 reared13 in intensive13 culture13 facilities13 Exercise13

conditioning13 and predator-shy‐recognition training may also increase survival of stocked fish

and be more economically feasible than rearing fish to increasingly larger sizes prior to

stocking13 The success13 of traditional fish hatchery programs is measured largely by the

number of fish stocked but hatchery programs for endangered species must measure

success in terms of long-shy‐term13 survival and species recovery (Brannon 1993 Anders 1998)

A specific list of research recommendations follows

Specific Research13 Recommendations13

bull Use replicated studies13 to establish optimum stocking13 densities13 for ponds13 and

tanks13 that can be used as13 a starting13 point for site specific refinement

bull Determine if sortinggrading13 improves13 overall growth rates13 in both ponds13 and

intensive culture facilities13

bull Investigate the use of artificial fertilizers13 to improve growth of both juvenile

and adult razorback suckers13 in ponds13

bull Determine if the razorback sucker diet gives13 better growth rates13 than cheaper

catfish or salmon feeds

bull Evaluate growth rates13 and production potential of new intensive culture

methods13 such as13 large circular tanks13

bull Evaluate13 long-shy‐term survival of fish produced from raceways13 and circular tanks13

compared to fish reared in ponds13

bull Evaluate more effective means13 of treating13 fish diseases13

bull Evaluate factors13 other than size that may increase post-shy‐stocking13 survival such

as13 exercise conditioning13 predator recognition training or rearing13 under more

natural settings13

28

13

II The Effect of Disease Treatments on Razorback Sucker

Growth

Section13 SummaryFormalin copper sulfate potassium permanganate and13 salt are all chemicals commonly13 used13 to13 treat13 Ichthyophthirius multifiliis outbreaks in captive razorback sucker (Xyrauchen13 texanus) Weexposed 190 juvenile13 razorback suckers (127 ndash 26 mm TL) to13 5 5-shy‐day treatments with13 each13 chemical to evaluate the effects13 these chemicals13 may have on growth Fish grew an average of23513 mm TL13 during the month13 study period Fish treated with formalin grew on average13 29mm TL (03 mmday) while fish treated with copper had the lowest growth averaging 20 mmTL (021 mmday) No significant differences in13 growth were observed among fish treatedwith any of the chemicals compared to untreated fish (pgt005) Reductions in growth13 as aresult of repeated chemical treatments are not likely the cause of differences in growth ratesamong13 facilities that raise razorback suckers Repeated chemical treatments may13 have otherimpacts to overall13 fitness or long-shy‐term survival but13 these effects were not13 evident13 in our study

29

13

Introduction

Preservation13 of razorback sucker13 (Xyrauchen texanus) currently13 depends on captive13

rearing and stocking programs until permanent solutions to factors that prevent wild13

recruitment are found Low survival of stocked razorback suckers (Brooks 1986 Marsh

and Brooks 198913 Marsh and Pacey13 2005) has caused target13 sizes for stocked fish to

steadily increase in efforts to reduce predation mortality (Marsh et al 2005 Schooley and

Marsh 2007) Rearing fish to larger sizes at hatcheries comes with increased costs and

creates the need to evaluate husbandry and rearing practices that may affect fish growth

Formalin copper sulfate potassium13 permanganate and salt are all chemicals

commonly used at razorback sucker rearing facilities to treat outbreaks of the protozoan

parasite13 Ichthyophthirius multifiliis ldquoIchrdquo is one of the most pathenogenic diseases of

cultured13 freshwater13 fishes (Matthews13 2005) and causes large13 losses in captive13 populations13

of endangered razorback sucker Each of these chemicals used to treat Ich only kill the free-shy‐

swimming life stage of the parasite13 requiring13 repeated doses over several13 days depending13

on water temperature These chemicals treatments are needed to prevent loss as a result

of disease outbreaks but the cumulative effects repeated disease treatments have on

growth13 are13 unknown

Copper13 sulfate13 has13 been shown to13 significantly13 reduce13 growth13 of channel catfish13 in

production13 ponds (Rabago-shy‐Castro13 2006) but it is unknown whether13 razorback suckers13

experience similar reduced growth following copper treatment Quantifying the impacts of

disease treatments on growth will help to interpret the wide differences in growth rates

observed13 at various13 razorback sucker13 production13 facilities13 throughout the13 southwest

(Ward et al 2007) If one chemical is found to have less detrimental impacts on growth

than another then it may be preferred for use as a disease treatment We evaluated growth

rates13 of razorback suckers13 under13 replicated13 and13 controlled13 conditions13 to13 assess13 effects13 of

repeated formalin copper sulfate and potassium permanganate and salt treatments on

growth13

Methods

We captured 190 juvenile razorback suckers from13 ponds at Bubbling Ponds Fish

Hatchery AZ using hoop nets or cast nets All fish were of the same age class and

30

13

averaged 179 mm total length (TL) (range13 = 127 ndash 262 mm TL)13 These fish were13 offspring13

of captive13 razorback sucker13 broodstock held13 at Dexter13 National13 Fish Hatchery13 NM13 (2007

year class) All fish were tagged with passive integrated transponder (PIT) tags and

quarantined for one month prior to the experiment to allow fish to recover from13 tagging

and become accustomed to being held in circular tanks

At the beginning of the study all fish were weighed measured and scanned for

individual tag numbers with 19 randomly selected fish placed into each13 of 10 8-shy‐foot

diameter circular tanks (Figure 2)13 Each13 tank contained13 two13 airstones13 and13 an13 individual

biofilter with a recirculating water pump (31 litersminute) that had been operating for

at least 1 month prior to the experiment to allow bacterial colonies to become

established Two tanks were designated as a control and did not receive any chemical

treatments while the other eight tanks received formalin copper sulfate potassium13

permanganate or salt treatments at two week intervals (two tanks per chemical

treatment) Formalin copper sulfate and potassium13 permanganate were treated at 1 part

per million (ppm) and salt was applied at 30 parts per thousand (ppt) These treatment

rates are commonly used to treat13 razorback13 suckers for ich at Bubbling13 Ponds Fish13

hatchery (Frank Agygos personal communication)

Figure 213 Photo ofexperimental tankswith individualbiofilters and aeration

31

13

Each treatment consisted of a series of doses applied on Wednesday Thursday and

Friday with a 90water change between each dose Biofilters were removed from13 all

tanks and held in a separate holding facility during treatments and then replaced on the

Monday following treatments after a 90water change This schedule allowed fish to be

exposed to chemical treatments for 5 consecutive days without water quality deteriorating

This 5-shy‐day chemical treatment was repeated every two weeks from13 July to October (97

days)13 for a total of 5 5-shy‐day treatments Water temperature in the treatment tanks ranged

from13 13degC (55degF) to 32degC (91degF)

Fish were fed a fixed ration of commercial razorback diet (Silvercup 4mm13 pellet)

once daily13 (2 percent body13 weight per day13 as calculated13 by13 average initial fish weight)13

At the end of the experiment all fish were again weighed measured and scanned for

individual tag numbers Growth of fish in each treatment group was compared using

analysis of variance (ANOVA) Any mortalities13 that occurred during the13 study13 were13

replaced with previously quarantined fish of equivalent size to maintain equal densities in

each13 tank13 but growth13 data was13 only13 recorded for fish which13 survived13 the13 entire13

experiment

Results

Fish at the13 start of the experiment averaged 179 mm TL (Range13 = 127 ndash 262 mm)

with no significant differences in fish length among treatment groups (F(4189) = 00183 p

gt 0999 ANOVA) On average fish grew 235 mm TL (024 mmday) during the 3 month

study13 Fish in tanks13 treated with formalin had the highest growth averaging 29 mm TL (03

mmday) while fish in tanks treated with copper had the lowest growth averaging 20 mm

TL (021 mmday) Fish in the control tanks averaged 213 mm TL in growth (022

mmday) (Figure13 3)13 Formalin-shy‐treated fish grew13 significantly faster than13 any other

treatment group but no13 significant differences in growth13 in length13 or weight were13

observed among fish treated with any of the chemicals compared to untreated (control)

fish (pgt005 ANOVA)

32

13

Figure 313 Average growthof razorback suckersexposed to a series of 5 5-shy‐day chemical treatmentsover a 97-shy‐day13 periodError bars representstandard error

Discussion13

Growth13 rates13 observed13 in our study13 (021 ndash 03 mmday) are low compared to those

reported13 in other13 studies13 of razorback sucker13 growth13 (0213 ndash 18 mmday) (Ward et al

2007) Using recirculating water systems for our study required filters to be removed and

replaced during treatments Stress to fish caused by removing and replacing filters within

the tanks as well as repeated water changes may have led to overall higher stress and

reduced growth rates compared to those reported for unconfined fish Growth in fish is

highly variable and is affected by many different physiological and environmental factors

including fish size density temperature amount of space and food (Brett 1979) We

strived to control each of these factors but other factors may have also influenced growth

in our experimental tanks During mid-shy‐summer water temperatures in the treatment

tanks reached 32degC (91degF) At these warm13 temperatures fish are very susceptible to

bacterial13 infections13 The slightly higher growth exhibited by fish in the formalin and

potassium13 permanganate treatments may have been the result of these two chemicals

33

13

being effective at controlling bacterial infections The differences in growth we measured

among treatment groups were not statistically significant and do not appear13 biologically13

meaningful during the relatively short duration of this study (97 days) although the

cumulative effects of slightly reduced growth could be biologically meaningful over longer

time frames

Reductions in growth13 as a result13 o repeated chemical treatments are not likely the

cause of differences in growth rates among facilities that raise razorback suckers

Repeated chemical treatments may have other impacts to overall fitness or long-shy‐term13

survival but these13 effects13 were13 not evident in our study It is more likely that the parasite

outbreaks themselves are the cause of different growth rates among razorback rearing

facilities rather than the chemical treatments used to treat the parasites We recommend

that hatchery managers continue to use the chemicals that are most effective at controlling

ldquoIchrdquo13 at their individual13 facilities

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower Colorado Rive Multi-shy‐species13

Conservation Plan under Work Task C10 We thank Ty Wolters and Tom13 Burke for their

support of this research and Frank Agygos and Dave Billingsly of the Bubbling Ponds Fish

Hatchery13 for their13 technical assistance13 and13 help with13 collecting13 fish

34

13

III13 Razorback Growth Rates at Bubbling Ponds ndash 2009-shy‐2011

Section13 SummaryExperimental studies at Bubbling Ponds Fish Hatchery AZ have strived to understand

factors that affect razorback sucker growth in captivity and identify ways to improve growthrates and maximize size at release Rather than performing experimental studies that wouldrequire major13 rearrangement (and likely reduced production)13 of hatchery operations our13 studies13 used normal variation in production techniques13 and practices13 to isolate factors13 thatmay modify growth rates

Our initial work identified razorback13 growth rates in13 lined ponds at standard fishdensity as 026 to13 028mmday (789 to 843 mmmonth) No significant differences in growthrate were observed among fish that had been in the pond only during the winter13 periodcompared to fish that had been in the pond the entire year indicating that water temperatures13 at Bubbling Ponds are high enough to allow fish to incorporate feed effectively year-shy‐roundHowever these growth rates are lower than most values reported from the literature fromnatural or semi-shy‐natural pond environments No significant differences in13 growth rate wereobserved13 between large and13 small fish13 within the 150 ndash 29 mm TL13 size range Additional worksuggests13 that razorback suckers13 tagged at over 300 mm TL had reduced growth rates (024mmday 73 mmmonth) as would be expected according to a typical Von13 Bertalanfy growthcurve although growth rates13 were only slightly less13 than the average growth rate for thehatchery (027513 mmday 82513 mmmonth)

Sorting13 to13 separate small fish from large fish after the first year of growth is practicedesigned13 to allow smaller fish to ldquocatch uprdquo to larger fish We found that13 this technique doesappear to13 improve growth rates of smaller fish Growth rates of sorted small razorback suckers(029 mmday 87mmmonth)13 were equal to that13 of larger13 fish (028 mmday 8413 mmmonth)indicating that sorting may have helped to offset their original slower growth trajectory

Bubbling Ponds Fish Hatchery grows razorbacks in 6 long deep ponds lined with heavyplastic 2 long deep13 earthen13 (unlined) ponds and three wide shallow earthen ponds The wideshallow ponds13 have historically produced very large fish at low density but have been found tomaintain much lower fish numbers than deeper ponds We found13 that growth13 rates ofrazorbacks kept at high density (4-shy‐700013 fish)13 in a wide shallow pond grew extremely slowly(024 mmday 726 mmmonth) This growth rate is among the slowest of any fish over theyears of our study and demonstrates that13 though the large ponds may produce large fish at lowdensity13 they are unable to overcome high13 fish13 densities

Finally one of the major factors influencing13 fish13 growth13 in hatcheries is disease onemajor summer-shy‐time disease at13 Bubbling Ponds is the ectoparasite Ich (Ichthiopthirusmultifiliis) To investigate the impact Ich has on razorback growth we eradicated fish from thespring and water conveyance ditch that supplies13 water to the hatchery using Rotenone This13 restoration effort was fairly short-shy‐lived (Ich returned to the hatchery within four months) but

35

13

growth13 rates of fish13 reared for four months without Ich present (031 mmday 92 mmmonth)were significantly higher than the following 8 months of growth for those same fish (022mmday 65 mmmonth) This disease-shy‐free growth rate is in fact faster than any13 otherprevious growth rates observed at the hatchery in our study

We conclude that growth rates at the Bubbling Ponds Fish Hatchery are likely as highas possible given the pond densities required to13 meet production goals and the Ich-shy‐infestedwater13 that feeds the facility Sorting practices are successful in helping as many fish as possiblereach stocking length as fast as possible Unlined ponds may be able to grow large fish at lowdensities but whatever factors allow for that growth13 are not able13 to overcome13 high fish densityThus the large lower ponds at Bubbling Ponds may be better utilized via renovation to13 deepenand line them

Disease is the most important factor limiting growth as may be expected to be the caseat many13 hatcheries While the spring renovation was not13 a complete success13 the dramaticreduction of fish populations in that habitat was enough to dramatically13 reduce13 the13 occurrenceof Ich at the hatchery13 Such open spring13 systems feeding a hatchery are a misfortune that canbe expected to transmit disease so we suggest that renovating the spring again to combat13 IchImproved techniques to divert water from13 the springs and more throuough treatment ofstream-shy‐side vegetation may improve the success of chemical treatment Successful renovationwould likely both improve growth rates and reduce chemical costs associated with treating Ichoutbreaks Even13 if complete renovation13 is impossible or impractical an13 effort to reduceinvasive fish density in the springs13 which act a vector for the parasite(and thereby reduce thelikelihood of13 Ich being transmitted into ponds) may still13 show dramatic improvements

36

13

Introduction

Conservation efforts13 for razorback sucker13 (Xyrauchen texanus)13 currently13 depend on

captive rearing and stocking programs Low survival of stocked razorback suckers (Brooks

1986 Marsh13 and13 Brooks13 1989 Marsh13 and13 Pacey13 2005) has13 caused13 target sizes for stocked13

fish to steadily increase in efforts to reduce predation mortality13 (Marsh13 et al13 2005

Schooley and Marsh 2007) Rearing fish to larger sizes at hatcheries comes with increased

costs and creates the need to evaluate husbandry and rearing practices that may affect fish

growth13 We evaluated growth13 rates13 of individual razorback suckers13 in ponds13 at Bubbling

Ponds Fish Hatchery13 using Passive Integrated13 Transponder (PIT) tags13 to13 obtain13 precise

growth information for individual fish so that valid comparisons of growth rates as related

to rearing practices can be made

Due to the critical nature of the razorback sucker stocking program we did not

design experimental studies that would require major rearrangement and potentially

reduce production of hatchery operations Instead our studies used normal variation in

production techniques and practices to isolate factors that may modify growth rates

Though this methodology dramatically limits replication and may limit our ability to

directly13 attribute13 differences in growth13 rates13 to13 the13 variables13 we13 investigate13 we13 were13 able13

to accomplish research goals without altering hatchery operations or impacting

production

From13 2009 through 2011 we conducted a series of observational13 growth13 studies to

determine growth rates of individual razorbacks at Bubbling Ponds The first set of

experiments included13 identifying13 growth13 rates13 in lined13 and13 unlined13 ponds determining

growth13 rates13 of fish at different13 sizes13 in13 relation13 to sorting13 practices and monitoring

razorback growth rates after removing the source of the ectoparasite13 Ich (Ichthiopthirus

multifiliis) from13 the hatchery water source13

Razorback growth rate in lined ponds

Our first growth study documented individual growth rates at normal density in 11

million gallon lined ponds13 over two13 years13 This is the standard13 grow-shy‐out process for

razorbacks13 at Bubbling Ponds We monitored growth of fish for a variety13 of sizes and13 the13

37

13

amount of time in a pond during the growing season These13 data give a snapshot of growth13

rates13 at the13 facility13 and13 provide13 the basis for comparisons throughout our study

Growth rate13 in an unlined pond

In addition13 to 6 ponds lined with heavy plastic13 sheeting13 Bubbling Ponds Fish13

Hatchery maintains two narrow and deep (same dimensions as lined ponds13 Figure13 4)13 and13

three large13 shallow unlined ponds These earthen13 ponds typically have vegetation and

associated aquatic invertebrates that may better simulate natural environments by

providing cover and improved food diversity or quality Therefore these unlined ponds

may be expected to produce higher growth rates and potentially improved survival that is

more similar to growth rates observed in more natural grow-shy‐out facilities13 Historically13 the13

large13 shallow13 ponds have produced very large fish when13 utilized at low13 fish density13 The

narrow13 deep earthen13 ponds are13 used to grow13 fry13 at high density in their first13 year of life

The major downside to unlined ponds is the difficulty in harvesting fish where a lined

pond might take 8-shy‐1013 people13 a half13 day13 to13 harvest13 lined13 ponds13 require13 intensive13 weeding13

to allow seines to be pulled and therefore require many more personnel-shy‐hours13 In addition13

to harvest challenges the shallow earthen ponds tend to suffer from13 dissolved oxygen

crashes during the summer Unlined ponds also may maintain higher13 populations13 of non-shy‐

target species such as bluegill sunfish mosquito fish and bullfrog tadpoles We measured

growth rates of suckers in a large shallow earthen pond for comparison to growth in lined

ponds13

Figure13 4 Lined13 and13 earthen ponds13 of similar dimensions (approx 1000000 gallons first

and second panels) and a large13 shallow13 earthen13 pond (third panel)

38

13

Effect of sorting on growth

Razorback13 suckers13 are13 currently13 sorted13 after their first13 year of growth13 They are13

typically removed from13 one of the13 upper earthen13 ponds and13 split into13 two13 lined13 ponds for

subsequent grow-shy‐out13 The larger13 fish (gt approximately 140 mm) are placed into one pond

and the smaller individuals in another It is possible that the larger fish were more

aggressive or adept13 at taking food so this sorting process is intended to allow smaller fish

to improve their growth rate

Effect of Ich on razorback sucker growth rates

We13 evaluated13 growth13 rates13 of razorback sucker13 in the13 presence13 and absence of the

ectoparasite13 Ich (Ichthiopthirus multifiliis) Ich outbreaks can occur in wild populations13 but

hatcheries13 have13 proven excellent locations13 for Ich because13 of very high fish densities13 which13

facilitate13 the13 transfer13 of Ich13 between13 fish This common fish parasite causes direct mortality13

to razorback13 suckers as well13 as secondary bacterial13 infections13

The open spring and13 ditch13 which13 provides water to the Bubbling13 Ponds Hatchery

has long13 been infested with mosquitofish (Gambusia affinis) that harbor13 the13 Ich parasite13

and allow13 it13 to enter the hatchery with incoming13 water13 The solution13 to13 the13 Ich problem13

was to remove the mosquitofish host using13 Rotenone Razorback13 sucker growth13 rates were13

then tracked in13 the absence of this parasite for 4 months and compared with growth rates

after Ich returned to the pond and from13 previous years

Methods

Razorback growth rate in lined ponds

On May 14 2008 141 razorback suckers were tagged with 12 mm PIT tags (1342

kHz) and placed in Pond 3 (approximately 1100000 gallons13 Figure13 4)13 at Bubbling13 Ponds

Fish Hatchery Fifty-shy‐three of these tags were recovered two months later when a large

Ichthyophthirius multifilis (Ich) outbreak killed many fish in the pond On October 15 2008

an additional13 145 PIT tagged13 fish were13 also placed into Pond13 3 On13 May13 14 2009 Pond13 3

was harvested and a total13 of 141 PIT tagged fish were recovered13 Of the tagged fish13 26 fish

had13 been13 in the13 pond since May13 of 2008 (378 days13 o growth) and 115 had been13 in13 the

39

13 40

pond since October13 15 2008 (211 days13 of growth) Numbers of fish in Pond 3 after the Ich

outbreak and for the majority of the period of growth were between 3 000 and 4000 fish

A Hobotempreg temperature13 logger13 was13 also13 installed13 in Pond 3 one meter below the water

surface13 near13 the13 outflow and13 recorded water temperature every 3 hours to allow analysis

of the effects of water temperature on growth rate (Figure13 5) This Hobotemp data is

representative of other pond temperatures throughout this study

In a second experiment 210 adult13 razorback suckers13 were13 PIT tagged13 on13 May 14

2009 and13 placed13 into13 Pond13 3 upper to13 evaluate13 growth13 rates13 of larger13 razorback suckers13 at

Bubbling13 Ponds Hatchery13 under current13 rearing13 conditions13 Size of these fish at tagging13

was (mean = 285 mm range = 205 ndash 396 mm) These fish remained in the pond for 257

days and were harvested on Jan 25 2010 to provide information on growth rates of larger

razorback suckers13 under13 current rearing conditions

Figure 513 Temperatures (degC) inrearing pond at BubblingPonds Hatchery from July toSept 2009 (top graph)13 andfrom Nov to Dec 2009 (Lowergraph) Temperaturesrecorded with a Hobotempregremote data logger13 every 3hours

13

Growth rate13 in an unlined pond

To document razorback sucker growth in earthen ponds we introduced13 225 tagged13

razorback suckers13 into13 Pond13 1 lower13 (Figure 4) in February 3 2010 Additional tagged fish

from13 other studies were added to the pond throughout the growing season and the density

of 1 lower reached a maximum13 of nearly 7000 fish in early summer 2010 Density was

reduced to approximately 6000 fish by capturing fish with hoop nets on June 3 2010 54 of

these fish were tagged fish and returned to 1 lower after being weighed and measured The

pond was harvested on January13 2713 2011 and a total13 of 254 tagged fish out13 of 4296 fish

total were removed from13 the pond The pond was harvested on January 27 2011 (358 days13

of growth) and the tagged fish were weighed and measured Total number of razorbacks in

the pond at harvest13 was 4296

Effect of sorting practices on growth rates

On March 1113 200913 Pond13 5 upper was13 harvested13 and13 split into13 two13 separate13 groups

Two hundred of the smaller fish (average size = 122 mm TL) were PIT tagged and placed

into13 Pond13 7 upper and13 200 of the13 larger13 fish (average = 160 mm TL) were PIT tagged and

placed int Pond13 8 upper Density13 in Pond13 7 was13 4500 fish and13 in Pond13 8 there13 were13 6500

fish These ponds were then harvested after 1 year and growth rates were compared to

give information on the effects of current sorting practices Hobotempreg temperature

loggers were installed in13 Ponds 7 and13 8 during13 the13 grow-shy‐out period with13 water13

temperature recorded every 2 hours13 (Figure13 6)

Effect of Ich on razorback sucker growth rates

Bubbling Ponds spring was treated with Rotenone (CFT Legumine 5) at a

concentration of 2 ppm13 to remove all mosquitofish from13 the spring The treatment

consisted of two treatments 6 hours in duration on two consecutive days (April 12 -shy‐ 13)

using13 drip13 stations13 and13 backpack sprayers13 followed13 by13 an13 additional 6 hours13 of

detoxification using sodium13 permanganate Although 12 mosquitofish were captured in the

spring pond the week following the treatments subsequent minnow trapping (20 traps

checked13 daily13 for 3 weeks) did not capture any additional fish until August 11 2010 when

41

13

juvenile mosquitofish were again detected in the spring pond Minnow traps have

subsequently been set daily with several hundred individuals removed To evaluate if Ich

was also again present in the spring we captured 15 mosquitofish from13 the spring pond on

three separate days and placed them13 in an aquaria at 25 degC with 5 longfin dace known to be

free of Ich These fish were monitored for 2 weeks with no signs of Ich developing This

indicates that even though mosquitofish have returned to the spring pond the parasite is no

longer present13 although how13 long13 this condition13 will13 persist13 is unknown13

On May 1113 201013 200 juvenile razorback13 suckers were harvested out13 of Pond 5

upper (2009 year Class from13 Dexter National Fish Hatchery) and were PIT tagged and

placed into Pond 8 to evaluate if growth rates at bubbling ponds hatchery have improved

following the renovation of the spring and the removal of the Ich parasite Unfortunately13

on Sept13 8 2010 Ich was13 again13 detected13 in Pond 8 and the pond was immediately seined

and 74 tagged fish were measured to obtain growth information for the 4-shy‐month period

during13 which13 the13 pond13 was13 Ich-shy‐free13

Figure13 6 Temperatures (degC) in rearingponds 7 and 8 at Bubbling Ponds Hatchery13 from March 2009 ndash March 201013 pond 7(top13 graph)13 and13 pond 8 (Lower13 graph)13 Temperatures recorded with a Hobotempregremote data logger every 3 hours

42

13

Results

Growth in Lined Ponds

Razorback suckers13 that had been13 in13 Pond 8 upper for the13 entire13 year13 grew an13

average of 0263 mmday (789 mmmonth) and razorback suckers that had been in the

pond for 7 months (Oct -shy‐ May) grew13 on13 average of 028 mmday (843 mmmonth) (Figure13

7) These growth13 rates13 did not significantly13 differ Fish density13 in Pond 3 during13 the13

majority of the growth period was13 00032 ndash 00036 fishgallon13 Additionally no13 significant

differences in growth rate were observed between fish smaller than 210 mm TL and fish

larger than 210 mm TL when all recaptured fish were combined

We also measured the growth rate of very large fish in a lined pond On Jan13 2513 201013

156 adult fish with PIT tags were recovered from13 Pond 3 upper13 These fish were13 in the13

pond for 257 days and experienced an average13 growth13 rate13 of 024mmday or 73

mmmonth (Figure13 7)13 This growth13 rate13 is slightly13 lower13 than13 the13 average13 growth13 rate13

observed13 at Bubbling13 Ponds Hatchery in other studies (0275 mmday 825 mmmonth)

but may not be biologically meaningful We would expect larger13 fish to13 have13 reduced

growth rates according to a typical Von Bertalanfy growth model (Bertalanffy 1957) but it

appears that13 over the size range we evaluated (300 -shy‐ 450 mm TL) growth rates have not

slowed significantly compared to that of smaller13 fish grown at Bubbling Ponds13 Hatchery

Growth13 of razorback suckers13 is known13 to13 slow as13 fish reach13 larger13 sizes but it appears13 this13

reduced growth rate may not really start to be biologically meaningful at Bubbling Ponds

Hatchery13 until razorback suckers13 exceed 450 mm TL

Growth in unlined ponds

Growth13 rates13 for the13 fish recaptured13 during13 the Pond 1 lower13 thinning13 (120 days13 in

the pond) was 024 plusmn 003 mmday (729 plusmn 090 mmmonth) (Figure13 8)13 Fish13 that were13 in

the pond for nearly the entire year grew13 an13 average13 of 024 plusmn 001 mmday (726 plusmn 027

mmmonth) These growth rates are surprisingly the lowest measured growth rates for

any part of our study and differ significantly from13 every other measured growth rate

except very large13 fish (Figure13 9)13 Separating13 out13 large fish that13 were in13 the pond for the

entire year makes no difference fish that were added to the pond at TL lt300 mm grew

43

13

Gro

wth

Rat

e (m

md

ay)

020

026

032

0244 plusmn 001 mmday (733 plusmn 028 mmmonth) and and those with TL gt= 300 mm at the

start of the experiment grew 022 plusmn 003 mmday (651 plusmn 101 mmmonth)

Razorback Growth Rates in Lined Ponds

Figure 7 Growth ofrazorback suckers in(mmday plusmn standard error)in Pond 8 upper in 2008-shy‐2009 An ANOVA did notdetect any significantdifferences

7 Months Full Year 300+ mm fish

Effects of sorting on growth

One hundred and seventy five tagged razorback suckers were recovered from13 Pond

8 upper13 on March13 24 2010 (378 days13 of growth)13 These were13 the13 larger sorted13 fish (gt140

mm TL) that came out of Pond13 5 on March13 11 2009 One13 hundred and13 twenty13 two13 tagged13

razorback suckers were also recovered from13 Pond13 7 upper on March13 31 2010 (385 days13 of

growth)13 These were13 the13 smaller sorted13 fish (lt140 mm TL) that came out of Pond13 5 on

March 1113 200913 No significant differences in growth rate (mmday) were observed among

larger fish in Pond 8 and smaller fish in Pond 7 (pgt005 ANOVA) (Figure 10)13 indicating

that13 sorting may have helped to offset the original slower growth trajectory of the smaller

fish Temperatures of Ponds 7 and 8 upper remained similar throughout the year13 (Figure

5)

44

13

13

13

Gro

wth

Rat

e (m

md

ay)

Gro

wth

Rat

e (m

md

ay)

020

026

032

020

026

032

Razorback Growth in an Unlined Pond

Figure 8 Growth of razorbacksuckers (mmday plusmn standard error) in Pond 1 lower (an unlined pond)in 2010-shy‐2011 An ANOVA did notdetect any significant differences

6 Months 12 Months lt 300 mm Fish 300+ mm Fish Growth Growth

Lined vs Earthen Ponds 1 year of growth

Figure 9 Growth of razorbacksuckers (mmday plusmn standard error) in lined and unlined ponds A t-shy‐test13 did not detect a significantdifference

Lined Pond Unlined Pond 1 Yr Growth 1 Yr Growth

45

13

Effect of Sorting G

row

th R

ate

(mm

day

) G

row

th R

ate

(mm

day

)

032

020

026

032

020

026

Smaller Fish Larger Fish

Effect of Ich

Figure 10 Average growthof razorback suckers(mmday plusmn standard error)that were size-shy‐sorted intosmall fish (pond 7) and largefish (pond 8) populations At-shy‐test did not detect asignificant difference

Figure 11 Average growth ofrazorback suckers (mmday plusmnstandard error) after Ich wasremovd from the hatcheryrsquos springand after Ich was again detected inthe pond The growth rate withoutIch is significantly higher than boththe rate after Ich and the ourstudyrsquos average annual growth ratein lined ponds (ANOVA p =00003)

Growth without Ich Growth With Ich Average Annual 4 months 4 months Growth Rate

46

13

Effect of Ich on razorback sucker growth rates

Seventy-shy‐four13 tagged13 razorback suckers13 were13 recovered from13 Pond 8 on September

15 2010 These fish had13 been13 in the pond for 4 months and experienced a growth rate of

032 mmday or 97 mmmonth (Figure13 11)13 This growth13 rate13 is significantly higher (p =

005 two sample t-shy‐test) than the mean growth rate for the same group13 of tagged fish after

Ich detection (022 mmday or 65 mmmonth) and significantly higher than any other

individual growth13 rates13 observed13 to13 date13 at Bubbling13 Ponds Hatchery13 (Figure13 11)13 If this13

growth13 rate13 were13 extended throughout13 the entire13 year13 fish on average from13 Ich-shy‐free13 ponds13

would be 16 mm longer than fish from13 ponds infested with Ich Studies conducted at

Bubbling Ponds hatchery in 2008 (Ward 2008) did not reveal any effects of the treatment

chemicals on razorback sucker growth rates so it13 is likely that13 the parasite outbreaks

themselves are causing reducing growth rates rather than the chemicals used to treat the

parasites13

Conclusions

Our results suggest that under typical hatchery operations (maximizing number of

fish produced)13 the growth13 rate13 of razorback13 suckers13 is relatively13 consistent at Bubbling13

Ponds hatchery13 at 02-shy‐03 mmday (6-shy‐9 mmmonth)13 but is lower than growth13 rates13 at

other13 facilities (02 ndash 18 mmday Ward et al 2007)13 This growth13 rate13 has13 been13 constant in

both lined and unlined ponds and at all fish densities we were able to measure To achieve13

growth13 rates13 substantially higher than this will likely require13 significant changes in rearing

practices that may not be practical in order to reach numerical production13 goals

Temperature is a key variable in fish growth but seasonal growth patterns

described13 above13 (Figure13 5) demonstrate that water temperatures are high enough in

winter to maintain razorback growth Differences in water temperature by season

currently13 do not fluctuate more than 10degC at Bubbling Ponds because of the continuous

supply of water flowing through each pond (approx 225 gallonsmin) These high water

flows appear to keep pond temperatures within the thermal preference13 for razorback

suckers13 (1213 -shy‐ 28 degC Bulkley and Pimentel 1983) throughout the entire year with

temperatures rarely dropping13 below 16deg13 C (Figures 513 6)13

47

13

Fish density is another key variable in fish growth and though the number of fish in

a pond during our study ranged from13 3000 to 700013 fish we13 did not find any13 correlation13

between13 density and growth rate13 This might yield two conclusions First13 razorback

growth13 may be changed equally13 by13 densities13 at the13 hatchery13 (ie13 a density13 of 3000 fish in a

pond is as stressful13 for razorbacks as a density13 of 7000 fish) An alternative is that other

factors13 such as disease outbreaks have13 stronger13 control over fish growth13 than13 density13

Fish density13 would13 have13 to13 be13 experimentally manipulated to test13 this13 and hatchery

operations (producing the maximum13 number of fish) prevented our manipulating density13

in ponds for this13 work The trouble with manipulating density demonstrates the difficulties

associated with changing13 hatchery13 practices experimenting with density would have

prevented BPH from13 meeting13 production13 goals Given that the stocking of smaller

razorbacks has met with very little success perhaps BPH goals could be changed from13

producing 12000 fish at 300+ mm per year to a smaller number of very large fish each

year Growing13 fewer13 larger13 fish could potentially be accomplished in the same time frame

as more smaller fish but a better understanding of how density alters growth rate would

be required to be confident13 of this

The very slow growth13 in the13 earthen13 unlined13 Pond 1 lower13 was very surprising We13

had13 anticipated13 that the13 diversified diet13 cover and13 other13 habitat features13 provided by13

unlined ponds would yield dramatically increased growth rates However these traits were

not enough to offset high fish densities and in fact the unlined pond in our study13 suffered

mortality to bring densities down to that observed normally in lined ponds

Our data13 suggest13 that razorbacks13 sucker13 growth13 rates13 are13 higher in lined13 ponds13

However we13 think the reasons13 for the13 very slow growth we observed13 in the13 unlined13 pond13

in our study13 is instead13 linked13 to13 the13 usage13 of Pond 1 lower13 during13 the13 study13 rather13 than13

intrinsic13 slow growth13 in earthen13 ponds First the pond was at extremely high density for at

least part of the study The volume of Pond 1 lower has not been estimated but hatchery

managers suggest 1500-shy‐2000 fish is an appropriate number of individuals so this pond

was at a very high density for much of the experiment Second dissolved oxygen is often

very low in the13 large13 earthen13 ponds during the heat of summer much lower than that of

lined ponds This will both limit the number of fish that can survive in the pond and almost

certainly13 increases stress13 of these13 fish potentially13 reducing growth13 The DO crashes also13

48

13

limit the amount of feed hatchery managers can give fish in these ponds sometimes for

days or weeks at a time which further reduces growth during warm13 weather

Our data13 suggests that13 growth rates at the Bubbling13 Ponds Fish Hatchery are likely

as high as possible given13 the pond densities required to meet production goals and the Ich-shy‐

infested water that feeds the facility Sorting practices are successful in helping as many

fish as possible reach stocking length as fast as possible Unlined ponds may be able to

grow13 large13 fish at low13 densities13 but whatever factors allow13 for that13 growth are not13 able to

overcome high fish density The removal of invasive13 fis that act as13 a host for the13 parasite13

Ich fish from13 the Bubbling13 Ponds spring13 allowed the highest13 growth rate at 032 mmday13

(96 mmmonth) but that growth rate decreased again as Ich re-shy‐infested13 the13 hatchery13

Consistently13 achieving13 growth13 rates13 as high or substantially13 higher than13 this13 will likely13

require13 significant changes in rearing practices that may not be practical in order to13 reach13

numerical production13 goals

Two major changes that might result in higher growth rates are substantially

reducing fish density and modifying the way spring water is delivered to the facility (via

either repeated chemical treatments or enclosed concrete water diversions) to eliminate

Ich from13 the hatchery source water Other potential changes not address by our work

include13 flow-shy‐training razorbacks much previous literature including MSCP-shy‐funded13 work

on razorback suckers13 suggests13 that fish growing13 in flowing water will grow13 faster than fish

in still water (Jorgensen and Jobling 1994) Furthermore there are a wide variety of

potential benefits associated with growing13 fish13 in flowing13 water in addition13 to increased

growth13 rates13 (Davidson13 199713 Castro13 et al13 2011) Another option13 for increasing13 growth13

rates13 include13 changing to13 intensive13 culture13 in large circular13 tanks

Finally given that the stocking of smaller razorbacks has met with very little

success13 perhaps13 BPH13 goals13 could13 be13 changed from13 producing 12000 fish at 300+ mm per

year to a smaller number of very large fish each year Growing fewer larger fish could

potentially be accomplished in the same time frame as more smaller fish but a better

understanding13 of how density13 alters growth13 rate13 would13 be13 required to13 be13 confident of this

49

13

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower13 Colorado13 River Multi-shy‐Species13

Conservation Program13 (LCRMSCP) under Work Task C10 We13 thank Ty Wolters13 Tom13

Burke13 and Eric13 Volkman for their support of this research and Frank Agygos and Dave

Billingsly13 of the Bubbling13 Ponds Fish Hatchery13 for their willingness to participate in13 this

research13 and13 for their technical assistance We also thank the LCRMSCP fish group from13

Boulder City13 NV for their assistance with harvesting13 ponds and tagging13 fish13

50

13

Literature13 CitedAnders P J 1998 Conservation aquaculture and endangered species can objective science13

prevail13 over risk13 anxiety Fisheries 23(11) 28-shy‐31

Anderson R O and R M Nuemann 1996 Length weight and associated structural indicesPages 447 ndash 482 in B R Murphy13 and D13 W Willis13 editors13 Fisheries techniques13 2ndedtion American Fisheries13 Society13 Bethesda13 Maryland

Bain M B J T Finn and H E Brooks 1988 Streamflow regulation and fish communitystructure13 Ecology13 69382-shy‐392

Bays J H Zarbock R Whitman and T Murphy 2005 Conceptual design and managementof native13 fish refugia on the13 lower13 Colorado13 River In13 CL Spring13 and13 S Leoneditors Proceedings of two symposia Restoring native fish to the lower ColoradoRiver13 interactions13 of native and non-shy‐native13 fishes 13ndash1413 July13 1999 Las13 Vegas13 Nevada13 Restoring13 natural function within a modified riverine environment thelower Colorado River13 8ndash913 July13 1998 U S Fish and13 Wildlife13 Service Southwestern13 Region Albuquerque New Mexico Pages 167-shy‐177

Bertalanffy L Von 1957 Quantitative laws in metabolism13 and growth13 Q Rev Biology 32217 ndash 231

Bingham T B Scheer and C McAda 2003 Propagation facilities in Grand Valley (24 RoadHatchery Horsethief13 Ponds and13 grow-shy‐out ponds) for captive13 rearing13 ofendangered13 fishes for the13 upper13 Colorado13 River basin13 Colorado River RecoveryProgram FY2003 annual project report13 US Fish and13 Wildlife13 Service GrandJunction13 4pp

Birchell G J and K Christopherson 2004 Survival growth and recruitment of larval andjuvenile razorback13 sucker (Xyrauchen texanus) introduced13 into13 floodplain13 depressions13 of the13 Green River Utah13 Final report13 Upper13 Colorado13 RiverEndangered Fish Recovery Program13 Project No C-shy‐6RZ Publication Number 04-shy‐1513 Utah13 Division of Wildlife13 Resources Salt Lake13 City13 Utah13 67 pages

Brannon E L 1993 The perpetual oversight of hatchery programs Fishery Research 1819-shy‐27

Brett J R 1979 Environmental Factors and growth pages 599-shy‐67513 InW S Hoar13 D13 J13 Randall and J R Brett (eds) Fish Physiology Volume 8 Bioenergetics and GrowthAcademic Press New York

Brooks J E 1986 Annual reintroduction and monitoring report for razorback suckerXyrauchen texanus in the Gila River Basin Arizona 1985 US Fish and WildlifeService13 Offices of Endangered13 Species and Fishery13 Resources Albuquerque 23 pp

51

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Brunson13 R E and K D13 Christopherson13 200513 Larval13 razorback13 sucker and bonytailsurvival and13 growth13 in the13 presence13 of nonnative13 fish in the13 Baeser13 floodplainwetland of the middle Green River Final report prepared for Upper13 Colorado RiverBasin Endangered Fish Recovery Program Project No C-shy‐6-shy‐rz-shy‐bt Publication13 No 05-shy‐26 Utah13 Division of Wildlife13 Resources13 Vernal13 32 pp

Bulkley R V and R Pimentel 1983 Temperature preference and avoidance by adultrazorback suckers Transactions of the American Fisheries Society 112601-shy‐607

Burke13 T13 199513 Rearing13 wild razorback13 sucker larvae in13 lake-shy‐side13 backwaters13 LakeMohave ArizonaNevada Proceedings of the Desert Fishes Council 2635

Busacker G P I R Adelman and E M Goolish13 199013 Growth13 Pages 363 ndash 387 in C BSchreck and p B Moyle editors Methods for fish biology American FisheriesSociety Bethesda Maryland

Castro V B Grisdale-shy‐Helland S J Helland T Kristensen S M Jorgensen J Helgrud13 GClaireaux A P Farrell A Krasnov and H Takle 2011 Aerobic training stimulatesgrowth and promotes disease resistance in Atlantic salmon (Salmo salar)Comparative Biochemistry and Physiology -shy‐ Part A Molecular amp IntegrativePhysiology13 160(2) 278-shy‐290

Czapla T E 2002 Facilities plan for the production of endangered fishes to meet statestocking13 plans13 as13 part of the13 Upper13 Colorado13 River Endangered13 Fish RecoveryProgram Upper Colorado River Basin Recovery Implementation Program US Fishand Wildlife Service13 Denver13 9 pp

Davidson W 1997 The effects13 of exercise13 training on teleost fish a review of recentliterature Comput Biochem Physiol 117A67ndash75

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Gerking13 S D 1978 Ecology of freshwater fish13 production13 Halstead Press13 New13 York

Gustafson W and Q Bradwisch 2000 Wahweap operation and maintenance -shy‐-shy‐ UtahColorado River Recovery Program FY 2000 annual project report Project No 29cUtah13 Division of Wildlife13 Resources Page AZ 3pp

52

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Hamman R L 1985 Induced spawning of hatchery-shy‐reared13 razorback sucker ProgressivFish Culturist 47(3) 187-shy‐189

Hanson J N 1996 Annual report fiscal year 1996 Willow Beach National Fish HatcheryUS Fish and Wildlife Service13 Willow Beach 9pp

Irving D S Seversen and M Montagne 2004 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2004 annual project13 report Report No 29b US Fish and13 Wildlife13 Service Vernal 3pp

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Kaeding L R and D B Osmundson 198913 Colorado13 Squawfish13 and13 razorback sucker grow-shy‐out pond studies as part of conservation measures for the green mountain andRuedi reservoir water sales Final report for agreement number 6-shy‐AA-shy‐60-shy‐00150

Koebele13 B P13 198513 Growth and the size hierarchy effect an experimental assessment ofthree proposed mechanisms activity differences disproportional food acquisition13 pysiological stress Environmental Biology of Fishes 12 181-shy‐188

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Marsh13 P13 C13 1987a13 Digestive tract13 contents13 of adult razorback suckers13 in Lake13 MohaveArizona-shy‐Nevada Transactions of the American Fisheries Society 116117-shy‐119

Marsh P C 1987b Native fishes at Buenos Aires National Wildlife Refuge and ArizonaState University Research Park Arizona opportunities for management researchand public13 education13 on13 endangered species13 Proceedings of the Desert13 FishesCouncil 1967-shy‐78

Marsh P C 1994 Rearing native Colorado River fishes in golf course ponds Arizona StateUniversity Tempe 22 + pages

Marsh13 P13 C13 200013 Fish population13 status and evaluation13 in13 the Cibola13 High Levee PondFinal report agreement number 99-shy‐FG-shy‐30-shy‐00051 US Bureau of ReclamationBoulder City13 Nevada13 20 pages

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53

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Marsh P C B R Kesner and C A Pacey 2005 Repatriation as s management strategy13 to13 conserve a critically13 imperiled fish species North American Journal of FisheriesManagement 25 547-shy‐556

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Marsh13 P13 C13 and J13 E Brooks13 198913 Predation13 by ictalurid catfishes as a deterrent13 toreestablishment of hatchery-shy‐reared13 razorback sucker The Southwestern Naturalist34188-shy‐195

Matthews R A 2005 Ichthyopthirus multifiliis Fouquet and Ichthyopthirosis infreshwater13 teleosts13 Pages13 159-shy‐218 in Advances in Parasitology volume 59 J RBaker R Muller D Rollinson (eds) Academic Press

McCarthy13 M S and W L Minckley 1987 Age estimation for razorback sucker (PiscesCatostomidae) from13 Lake Mohave Arizona and Nevada Journal of the Arizona-shy‐Nevada Academy of Science 2187-shy‐97

Minckley13 W L13 198313 Status of the razorback13 sucker13 Xyrauchen texanus (Abbot)13 in13 thelower Colorado River basin13 The Southwestern13 Naturalist13 28(2) 165-shy‐187

Minckley13 W L13 199113 Native fished of the Grand Canyon13 region an obituary13 Pages 124-shy‐177 in Colorado River ecology and dam13 management National Academy PressWashington13 DC

Minckley13 C13 O and M LaBarbara13 199913 Report13 on13 native fish grow-shy‐out facilities13 at Cibolaand Imperial National Wildlife Refuges 1993-shy‐199513 US Fish and13 Wildlife Service13 Parker Fishery Resources Office Parker Arizona

Modde13 T13 199613 Juvenile razorback sucker (Xyrauchen texanus) in a managed wetlandadjacent13 to the Green13 River13 Great13 Basin13 Naturalist13 56375-shy‐376

Modde T KP Burnham and E J Wick 1996 Population status of the razorback sucker13 inthe middle Green River (USA) Conservation13 biology 10 110-shy‐119

Modde13 T13 and G13 B Haines13 200513 Survival13 and growth of stocked razorback13 sucker andbonytail in multiple floodplain wetlands of the middle Green River under resetconditions13 Final report prepared for Upper Colorado13 River13 Basin RecoveryImplimentation Program US Fish and Wildlife Service Vernal 66 pp

54

13

Modde T Z H Bowen and D C Kitcheyan 2005 Spatial and temporal use of a spawning13 site in the middle Green River by wild hatchery-shy‐reared13 razorback suckers13 Transactions of the American Fisheries Society 134937-shy‐944

Mueller13 G13 199213 The native fish work13 group13 -shy‐ a multiagency endeavor to improve thestatus of the razorback sucker in Lake Mohave AZ-shy‐NV13 Proceedings of the DesertFishes Council 2369

Mueller G 1995 A program13 for maintaining the razorback sucker in Lake MohaveAmerican Fisheries Society Symposium 15127-shy‐135

Mueller13 G13 200613 Ecology of the bonytail13 and razorback13 sucker and the role of offchannelhabitats13 in their13 recovery Scientific13 investigations13 report 2006-shy‐5065 US GeologicalSurvey13 Denver

Mueller G and E Wick 1998 Testing of golf course ponds at Page Arizona for suitability13 as grow-shy‐out facility for razorback sucker using surplus fish from13 Ouray NationalFish Hatchery National Park Service US Fish and13 Wildlife13 Service and UtahDivision of Wildlife13 Resources 28 pages

Mueller13 G13 and T13 Burke13 200513 Survival13 of young13 razorback13 sucker (Xyrauchen texanus) inrelation to13 stocking rates13 (fishha)13 and13 in the presence13 or absence13 of predatorcommunities in Lake Mohave Arizona-shy‐Nevada13 Pages13 155-shy‐16313 in Proceedings of two13 symposia restoring native fish to the lower Colorado River interaction13 of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 Nevada US Fish and Wildlife13 Service Southwest Region Albuquerque New Mexico

Mueller13 G13 J13 Carpenter13 and P13 C13 Marsh13 200413 Cibola13 High Levee Pond annual report 2004US Geological Survey Fort Collins13 Science Center13 Colorado13 and Arizona StateUniversity Tempe 23 pages

Nesler T P K Christopherson J M Hudson C W McAda F Pfeifer and T E Czapla 2003An integrated stocking plan for razorback sucker bonytail and Colorado13 pikeminnow for the Upper Colorado River Endangered Fish Recovery ProgramAddendum13 to State Stocking Plans Upper Colorado River Basin Recovery13 Implementation Program 12 pp

Papoulias13 D and W13 L Minckley13 1992 Effects13 of foo availability13 on survival and growth13 of larval razorback suckers13 in ponds Transactions of the American Fisheries Society121340-shy‐355

Paukert13 C P D L Ward13 P J Sponholtz13 and K13 D Hilwig13 Effects13 of repeated hoopnetting13 on bonytail chub13 Journal of Freshwater13 Ecology13 20(4) 649-shy‐653

Pfeifer F M13 C Baker13 and M13 Montagne13 199913 Propagation13 facilities13 in the13 Grand Valley13 (24 Road13 Hatchery13 Horsethief13 Ponds and13 grow-shy‐out ponds) for captive rearing of

55

13

endangered13 fishes for the13 Upper Colorado13 River Basin13 Colorado13 River Recovery13 Program FY 99 annual project report Project No 29a13 US Fish and Wildlife Service13 Grand13 Junction13 5pp

Pfeifer F S Seversen and M Montagne 2003 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2003 annual reportProject No 29b13 US Fish and Wildlife13 Service Vernal13 4pp

Rabago-shy‐Castro J L Sanchez13 J G Perez-shy‐Castaneda R and13 Gonzalez-shy‐Gonzlez A 2006Effects of the prophylactic use of Romet-shy‐3013 and13 copper13 sulfate13 on growth13 condition13 and feeding13 indicies in13 channel13 catfish (Ictalurus punctatus) Aquaculture 253 343-shy‐349

Reinitz GL L E Orme and F N Hitzel 1979 Variations of body compositio and growth13 among strains of rainbow trout Transactions of the American Fisheries Society 108204-shy‐207

Ruppert13 J13 B P B Holden13 and P D Abate 1999 Age estimation and growth of razorbacksucker13 Xyrauchen texanus in Lake13 Mead Nevada Proceedings13 of the Desert FishesCouncil 3040

Schnoor K D and J Logan 2002 Operation and maintenance of JW Mumma nativeaquatic13 species restoration facility Colorado Colorado River Recovery Program FY2002 annual project report13 Project No 29d Colorado13 Division of Wildlife Alamosa3pp

Salisbury13 L13 1998 Factors13 affecting razorback13 sucker growth13 in Lake13 Mohave backwaters13 MS Thesis13 Unviersity13 of Nevada13 Las13 Vegas

Schooley J13 D13 and P C13 Marsh13 2007 Stocking of endangerdd13 razorback13 suckers13 in thelower Colorado River Basin13 over three decades 1974-shy‐2004 North American Journalof Fisheries Management 27 43-shy‐51

Severson S H H M Tyus and G B Haines 1992 An evaluation of feeds for raisingrazorback sucker Xyrauchen texanus Journal of Applied Aquaculture 155-shy‐65

Toney D P 1974 Observations13 on the13 propagation13 and13 rearing13 of two13 endangered species13 in a hatchery environment Proceedings of the Annual Conference of the Western13 Association of State Game and Fish Commissions 54 252-shy‐259

Tyus H M13 1998 Razorback sucker13 (Xyrauchen texanus) recovery plan13 University13 ofColorado Center for Limnology Boulder13 76 pages

Tyus H M13 and13 S H Severson 1990 Growth13 and13 survival of larval razorback suckers fedfive formulated diets The Progressive Fish Culturist 52197-shy‐200

56

13

Ulibarri M E 2003 Annual report fiscal year 2001 Dexter National Fish Hatchery13 andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 26 pages

Ulibarri M E 2003 Annual report fiscal year 2002 Dexter National Fish Hatchery andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 59 pages

USBR 2006 Lower13 Colorado13 River Multi-shy‐Species Conservation Program final fishaugmentation plan Boulder City 19 pp

USFWS 2002 Razorback sucker (Xyraouchen texanus) recovery goals Amendment andsupplement to the Razorback Sucker Recovery Plan13 US Fish and Wildlife Service13 Region 6 Denver13 Colorado

USFWS 1999 Annual report 1999 Ouray National Fish Hatchery Vernal 25pp

USFWS 2004 Management plan for the big-shy‐river13 fishes of the13 lower13 Colorado13 river basinamendment and supplement to the bonytail humpback chub Coloradopikeminnow and razorback sucker recovery plans

USFWS13 2005 Station13 profile13 of the13 Dexter13 National Fish Hatchery13 and Technology CenterUS Fish and Wildlife13 Service Dexter

Valdez R A P G Mangan R Smith and B Nilson 1982 Upper Colorado River fisheriesinvestigations13 inW H Miller J J Valentine D L Archer H M Tyus R A Valdezand L13 Kaeding13 editors13 Colorado River Fishery13 Project13 Part 2 Field13 investigations13 US Bureau of Reclamation Salt Lake City Utah

WBNFH 2004 Culture methods of the endangered razorback sucker Xyrauchen texanusUS Fish and Wildlife13 Service Willow Beach National Fish Hatchery13 8 pp

Ward D 2008 Effects of disease treatments on growth of razorback sucker ReportSubmitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 Inpartial fulfillment of work task C10 agreement number 06FG30039

Ward13 D13 M Childs and W Persons 2007 Factors13 affecting13 growth13 of razorback sucker13 (Xyrauchen texanus) in captivity Literature review and knowledge assessmentReport Submitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 In partial fulfillment of work task C10 agreement number 06FG30039

57

Appendices

Appendix 1 Survey Questions Survey of Razorback Sucker Culture in the

Southwestern United States

The enclosed survey is being distributed by the Arizona Game and Fish Department to razorback sucker culture facilities throughout

the Southwestern United States The purpose of this survey is to consolidate information regarding culture of this species so that

appropriate facility improvements can be considered for Bubbling Ponds Hatchery in Arizona Specifically we wish to increase

growth rate and production efficiency at the hatchery Information gathered in this survey will be summarized in a final report to US

Bureau of Reclamation in Boulder City NV and disseminated to all facilities that participate in the survey A workshop to discuss

the findings of this study as well as to share general information concerning razorback sucker culture will be organized by the

Arizona Game and Fish Department at the conclusion of this study and all participants will be invited

Thank you for taking the time to fill out this survey Please contact Mike Childs if you have questions or would like to discuss the

survey

Mike Childs

mchildssedonanet

(928) 639-1346

(928) 634-1279

Facility_____________________________________ Date___________________

Contact Phone _____________________________

ContactPerson_______________________________

Contact Email _______________________________

1 Water quality ranges at this culture facility

Season

Spring (Mar-May) Summer (Jun-Aug) Fall (Sept-Nov) Winter (Dec-Feb)

Temperature (C)

PH

DO (mgL)

PO4 (mgL)

TDS (mgL)

Hardness (mgL)

CaCO3

Pathogens

37

13

Pond growth studies

Growth13 studies13 were13 conducted13 at the13 Bubbling Ponds Fish Hatchery from13 2009 to

2011 These studies13 were13 largely13 observational13 because hatchery production requirements

prevented experimental manipulation of dependent variables Our initial13 work13 identified

razorback growth rates in lined ponds at standard fish density as 026 to 028mmday

(789 to 843 mmmonth) Additional13 studies include observations of growth rates in13 lined

and unlined ponds13 fish at different13 densities13 sorting13 practices13 and growth in13 the absence

of the13 ectoparasite13 Ich

Our data13 suggests that13 growth rates at the Bubbling13 Ponds Fish Hatchery are likely

as high as possible given the pond densities required to meet production goals and the Ich-shy‐

infested water that feeds the facility Sorting practices are successful in helping as many

fish as13 possible13 reach13 stocking13 length13 as13 fast as13 possible13 Unlined13 ponds may be able to

grow13 large13 fish at low densities but whatever factors13 allow for that growth13 are13 not able to

overcome high fish density Growth rates were highest following removal of Ich from13 the

Bubbling13 Ponds Spring13 032 mmday (96 mmmonth) but that growth13 rate13 decreased13

again13 as Ich re-shy‐infested13 the13 hatchery

Conclusions

We conclude that under typical hatchery operations (maximizing number of fish

produced)13 the growth13 rate13 of razorback13 suckers is relatively13 consistent at Bubbling13 Ponds

hatchery13 at13 02-shy‐03 mmday (6-shy‐9 mmmonth)13 but is lower than growth13 rates13 at other

facilities (02 ndash 18 mmday Ward et al 2007)13 This growth13 rate13 has13 been13 constant in both13

lined and unlined ponds at all fish densities we were able to measure is temperature

independent13 and13 is likely13 enhanced13 by13 separating13 fast and13 slow-shy‐growing13 fish after the first13

year of growth13 To achieve13 growth13 rates13 substantially13 higher than13 this13 will likely13 require

significant changes in rearing practices that may not be practical in order to13 reach13

numerical production13 goals

Two major changes that might result in higher growth rates are substantially

reducing fish density and modifying the way spring water is delivered to the facility (via

either repeated chemical treatments or enclosed concrete water diversions) to eliminate

Ich from13 the hatchery source water Other potential changes not address by our work

6

13

include13 flow-shy‐training razorbacks much previous literature including MSCP-shy‐funded13 work

on razorback suckers13 suggests13 that fish growing13 in flowing13 water13 will grow faster13 than13 fish

in still water (Jorgensen and Jobling 1994) Furthermore there are a wide variety13 of

potential benefits associated with growing13 fish13 in flowing13 water in addition13 to increased

growth13 rates13 (Davidson13 1997 Castro13 et al 2011)13 Finally given that stocking of smaller

razorbacks13 has13 been13 largely unsuccessful13 perhaps13 BPH goals could be changed from13

producing 12000 fish at 300+ mm per year to a smaller number of very large fish each

year Growing fewer larger fish could potentially be accomplished in the same time frame

as more smaller fish but a better understanding13 of how13 density alters growth rate would

be required to be confident13 of this

7

13

I Literature13 Review

Section13 SummaryThe few remaining razorback sucker populations are sustained by captive rearing and stockingprograms Captive-shy‐reared razorback suckers commonly13 experience13 high predation whenstocked into natural environments This13 creates13 the need to rear fish to larger sizes13 in captivityand to13 find new ways to13 improve growth for captive-shy‐reared fish We reviewed publishedliterature and agency reports for information on factors that affect growth of13 razorback suckerSite visits to13 razorback sucker production facilities and surveys of fish hatchery13 personnel wereconducted to obtain information on current rearing practices Razorback sucker growth is13 extremely13 variable13 and impacted by13 many13 factors including13 fish size13 and age sex densityamount of living13 space quality13 and quantity13 of food genetics and temperature This makesevaluations of individual factors that affect growth difficult Culture13 practices for razorbacksuckers13 vary widely and include differences13 in rearing environments rearing densities feedingregimes and types of feed as well as grading or13 sorting practices The focus at most razorbackrearing facilities is production so the types of data that are collected13 are often insufficient fordetailed13 evaluations of rearing practices on growth Calculated13 growth13 rates from theliterature vary widely and range from 02 ndash 1813 mmday Typically the highest growth13 rates arereported from natural or semi-shy‐natural pond environments These growth rates indicate thatjuvenile razorback suckers have a very high growth potential under ideal rearing conditionsDetailed replicated studies are needed to accurately compare the effects of individual rearingpractices on13 growth These types of studies will ultimately provide both time and cost-shy‐savings13 to production facilities by reducing the time it13 takes for razorback suckers to reach stockingsize improving overall production efficiency

8

13

Introduction

State and federal wildlife management agencies have been rearing razorback

suckers in captivity since the 1970rsquos (Toney 1974 Hamman 1985) to augment declining

natural13 populations Both wild-shy‐caught larvae13 and captive-shy‐bred fish are reared at fish

hatcheries13 and13 grow-shy‐out ponds throughout the13 southwestern13 United13 States13 (reviewed13 in

Mueller 2006) Each facility has unique environmental conditions and different rearing

methods which yield different growth rates Unlike commercial fish species which have

been cultured and studied extensively little published information is available on the

effects of various rearing methods on growth of razorback sucker

Low survival rates13 of stocked13 razorback suckers13 (Brooks13 1986 Marsh13 and13 Brooks13

1989 Marsh13 and13 Pacey13 2005)13 have13 caused13 target sizes for stocking13 to13 steadily13 increase13 in

efforts to reduce predation mortality (Marsh et al 2005 Schooley and Marsh 2007)

Rearing fish to larger sizes comes with increased costs and creates the need to know which

factors13 have the greatest impact on growth rate and how these factors can be controlled to

maximize growth This document compiles and summarizes information on current

captive13 rearing practices13 and associated13 growth13 rates13 for razorback sucker13

We reviewed relevant13 published literature and agency reports on13 razorback13 sucker

to compile background information regarding the effects of environmental factors and

rearing methods on growth A questionnaire was developed (Appendix 1) and sent to

hatchery managers who rear razorback suckers Follow up surveys13 were13 also13 conducted13

by telephone (Appendix 2) Information on rearing densities water quality diseases and

management practices at each facility were recorded Site visits to Bubbling Ponds State

Fish Hatchery13 in Arizona Dexter National Fish Hatchery in New Mexico Grand Valley

Endangered Fish13 Facility13 in Colorado13 Ouray13 National13 Fish13 Hatchery13 in Utah and the Willow

Beach National Fish Hatchery in Arizona were also conducted as part of this knowledge

assessment Telephone interviews were conducted with personnel from13 other locations

that13 produce razorback13 suckers (Uvalde National13 Fish Hatchery13 Hualapai Ponds13 Lake

Mead Fish Hatchery and JW Mumma Fish Hatchery) or facilities that formerly produced

razorback suckers but currently focus on other species (Wahweap Fish Hatchery Achii

Hanyo13 National Fish Hatchery Mora National Fish Hatchery)

9

13

Information from13 all of these sources is summarized to aid future researchers in the

design of more detailed studies on razorback sucker13 growth Understanding the13 factors13

that13 control13 razorback13 sucker growth will13 allow13 expanded fish-shy‐rearing capabilities13 and13 aid13

in reaching management objectives for stocked fish Preservation of genetic resources for

razorback suckers13 depends on captive rearing and stocking programs until permanent

solutions to factors that prevent wild recruitment can be found

Summary13 of Facilities

There are13 over 50 locations13 that have13 been13 used to13 rear13 razorback suckers13 (Table13 1) These

include13 both13 intensive13 culture13 facilities13 with13 raceways13 or circular13 tanks13 as13 well as13

production13 ponds13 golf-shy‐course13 ponds and natural floodplain-shy‐wetlands The majority of

razorback suckers that are stocked come from13 six major production facilities Bubbling

Ponds State13 Fish13 Hatchery13 The Grand13 Valley13 Endangered13 Fish Facility13 and13 Dexter13 Ouray13

Willow13 Beach13 and Uvalde National13 Fish Hatcheries13 Tables 2-shy‐313 outline13 the13 types13 of fish

holding facilities and water quality conditions that exist at each of these main production

locations A brief summary of procedures for rearing razorback suckers at each of these

facilities13 follows

These summaries are based on interviews conducted with hatchery personnel in July 2007 during site visits

This information13 is provided only to give a brief overview of razorback grow-shy‐out procedures Please verify13

accuracy13 of specific information with individual hatchery managers

10

13

Table13 1 List of locations13 that have13 been13 used to13 grow-shy‐out razorback suckers

$$amp ()amp$+ ($ampamp$+( $amp()$+ $amp()amp+(-0(12(342056( )0(-75amp8(95amp( 0$$05(lt==gt( 5amp+(amp4amp(Aamp+amp050+(12(14$6( 5amp+(amp4amp8(B$5+( B7$(lt==lt8()C0C05(lt===8(D0$05(0($(lt==E8(amp2F(0($(lt==E(

GltHI5+(342056J( K0L05(Damp$(12(342056( K0L058(D0M(0L4( N$055(lt==E( FF(-0(12(342056( D05(9$F8(B$5+( -42amp5(amp+($amp(lt==lt( OP0(0+(342056( $+05(B68(D0Q+( N-R(lt==gt( S56(Damp$(12(342056( D05(T05amp$8(N2( B7$(lt==lt8(U5Qamp(0($(lt==H8()C0C05(0($(lt==E8(0$$05(lt==gt8(N-1V-(WXXX( NQ$+0(Damp$(12(342056( NQ$+08(Y0L( N-R(lt==gt( V2M07(12(342056( M058(N2( B7$(lt==lt8(Qamp(amp+(5+M42(lt===( V$$M(042(Damp$(12(342056( 0$M(3Q05(KF(amp(B$5+(RQ058(95amp( 3ampamp(WXXgt( 942(3amp6( D05()5P058(95amp( N-1V-(lt==Z( --+-0+-12-3(4-5 )005(7amp+( 5amp+(amp4amp8(B$5+( Y2+(amp2F8(705amp$(4FFamp4amp( ltgt(5+(7amp+( 5amp+(amp4amp8(B$5+( )C0C05(0($[(WXXX( amp+(7amp+(( 5amp+(amp4amp8(B$5+( )C0C05(0($[(WXXX( B$6F05()amp+( BampC$0amp40(C(B$5+(amp+(ampampamp( )C0C05(0($[(WXXX8(B7$(lt==lt( B$5+(I(W](++amp$($00+(7amp+( 5amp+(T$$068(B$5+( )C0C05(lt===( KP0(5+(7amp+( 5amp+(T$$068(B$5+( )C0C05(0($[(WXXX( 32$amp0(7amp+( 5amp+(T$$068(B$5+( )C0C05(0($[(WXXX( 35020C(505amp(7amp+( 5amp+(amp4amp8(B$5+( )C0C05(lt===8(B7$(lt==lt( 0-6-3+ $620(Famp47$($C(450( $6208(B$C5amp( ^50amp($C(450_(9-N(R00542()5P( 08(95amp( 52(WXXH8(52(WX]( )0($C(450(7amp+( )08(95amp( 0$$05(amp+(V4P(WXX]( 768639 0amp(50(DVR( -2(C(Y4amp8(95amp( 52(WX]( B$(32(O0Q00()amp+( B$(Damp$(V$+$C0(R0C08(D05($6208(B$C5amp( 52(lt===8(amp4P$06(amp+(O55(WXXX8(0$$05(lt==gt( SQ05amp(M$+$C0(amp0F0amp(50( D05(OP0(0+(ampC$M8(D0Q+( N-R(lt==gt( -0amp5(V2( D52(C(`F8(95amp( ^5042Fampamp(amp+(O0$0(lt==gt8(amp4P$06(amp+(O55(WXXX( )1(+ KQ(4Q0( OP0(2Q08(95amp( 0$$05(WXXlt8(0$$05(amp+(5P0(lt==Z( 95amp(aQ0amp$0( OP0(2Q08(95amp( -$56(WXX]( -2(-+0Mamp+05( OP0(2Q08(95amp( -$56(WXX]( `F(BQ0( OP0(2Q08(95amp( 0$$05(WXXlt8(0$$05(amp+(5P0(lt==Z( Kamp+6( OP0(2Q08(D0Q+( -$56(WXX]( D52(B20F020Q0( OP0(2Q08(D0Q+( -$56(WXX]( D52(X($0( OP0(2Q08(D0Q+( Y6(V$05(N-R8(705amp$(4FFamp4amp( V$$M( OP0(2Q08(D0Q+( Y6(V$05(N-R8(705amp$(4FFamp4amp( D0Q+(A( OP0(2Q08(D0Q+( Y6(V$05(N-R8(705amp$(4FFamp4amp( D0Q+(O5Q0( OP0(2Q08(D0Q+( Y6(V$05(N-R8(705amp$(4FFamp4amp( 0+58lt+--457(5 9Q0(50ampampamp( D05(T05amp$8(N2( )C0C05(0($[(lt==E( ampamp(5+0( D05(T05amp$8(N2( )C0C05(0($[(lt==E( 2ampamp(F( D05(T05amp$8(N2( ++0(amp+(3amp0(lt==Z( O0(W=( D05(T05amp$8(N2( N-1V-(WXXX( O0(F( D05(T05amp$8(N2( ++0(amp+(3amp0(lt==Z( S$+(425$06(V2( D05(T05amp$8(N2( ++0(amp+(3amp0(lt==Z8(++0(WXXgt( O00+(7amp+(amp(20(Namp2(amp( D05(T05amp$8(N2( U5Qamp(0($(lt==H8()C0C05(0($(lt==E( =($+ 1$6+(OF(0(75P(GY0$0(75ampJ( O(T08(D0Q+ (52(WXXH( Y5amp++(-0(amp5(B$$00( 9$F8(B$5+( -42amp5(amp+(Oamp(lt==lt( 5MI(7amp+( D05(15Fampamp8(D( -42amp5(amp+(Oamp(lt==lt(

11

13

Table 2 Facilities available at major razorback sucker fish hatcheries

$amp( )$+(-+( 0(1(2$amp3amp(( 4-56+ amp7(8-+1$(9+( lt3-5( 8=$33( 23gt(805(

$amp()amp+(-(012345( 0(0+amp(A(BBCC(05 ampD(ED F CGBH IACCCACCC BJH K$+L(0D

amp$+(M$gt$ O-$+(+($P

B N B

CGBH IACCCACCC BABHC FANCC

BJH

Qamp+-3$+($P F FHC 637134(801amp0$(-(012345( H(L$33gt($O-amp1+(gt33A(

BCCC(05 ampDRK$+L(0D amp$+(M$gt$ M$-3$+($P Qamp+-3$+($P Qamp+-3$+($P

9O-$+amp$

SF S BC SC HC TC

CGI((IGC( HAHCC HSC IBC BCC IC

9O-$+amp$ BC SC 940amp+(amp21amp(8013(-(-02$15( U-ampamp0$3(D+ampPamp(gt$+ Qamp+-3$+($P IS VCC IB

W+Lamp1(+$+amp(0D( E-50D(+ampX+(gt$+( Qamp+-3$+($P JT BCC H K$+L(ED T CGBH(Y(CGH(

lt405(801amp0$(-(012345( J(L$33gt(gt33A(FCC(05( ampD(0D BS CGIBH(Z(CGBH( IC Qamp+-3$+($P NC IBC H Qamp+-3$+($P BJ VCC IC((IH

=$$gt(302(801amp0$(-(012345( 3$+(L$D(Q3+$D( MampX+(gt$+( amp$+(M$gt$ N IAHCC

amp$+(M$gt$ IF IFACCC 9O-$+amp$ FC IC

0$+3(801amp0$(-(012345( B([0(9O-amp1+()33A( IHCC(05 ampD(0D II I

K$+L(0D amp$+(M$gt$ amp$+(M$gt$

NJ B IB

GBH(Y(IGC( FAHCC IACCC

Qamp+-3$+($P Qamp+-3$+($P

IB N

BCC NACCC

12

13

Table13 3 Water13 quality13 ranges13 at each13 culture facility$amp ($)$++) -+$

-)amp012$)32$45 -6+)01763865 9$01-+3lt5 =amp+)01gt+39+5 $amp()amp+ ++)$6)+01A5

J gtLNL01O5 8P$ampamp401O5 ($Q+

BC3DE DD3DF BG3DB KLM3MLE KLH3MLI KLH3MLF CLM3BFLE CLM3BFLE CLM3BFLE

RQS0Aamp$ RQS0Aamp$ RQS0Aamp$ )ampQTamp$ )ampQTamp$ )ampQTamp$

8+)$O(6+T$ 8+)$ 8+)$ A6$)amp A6$)amp A6$)amp

BH3BI KLH3MLE CLM3BFLE

RQS0Aamp$ )ampQTamp$ 8+)$ A6$)amp

-01 ++)$6)+01A5 J gtLNL01O5 8P$ampamp401O5 ($Q+

BK3DE DD3DM BK3DE KLC3MLC KLC MLC DLM3GLK DLM3GLK DLM3GLK BIC3BMM BIC3BMM BIC3BMM

2ampamp$03040UQ$0amp0)6Q0amp0UampQ0ampamp0VampQ

BE3BI KLC

DLM3GLK BIC3BMM

213amp+(4amp50amp ++)$6)+01A5 J gtLNL01O5 8P$ampamp401O5 ($Q+

DH3DC DH3DC DH3DC KLK3MLE KLK3MLE KLK3MLE KLE3KLC ILC3KLE ILE3ILC BEE BEE BEE

+0$0amp+amplt+066)+0V$ampamp4S0RQ0$0)TP0T

DH3DC KLK3MLE FLC3ILC BEE

6137 ++)$6)+01A5 J gtLNL01O5 8P$ampamp401O5 ($Q+

BB3DC BB3DC BB3DC KLF3MLD KLF3MLD KLF3MLD CLE3BD CLE3KLD CLE3KLD BBG BBG BBG Aamp$ Aamp$ Aamp$

BB3DC KLF3MLD CLE3KLD BBG Aamp$

8$$9(35 ++)$6)+01A5 J gtLNL01O5 8P$ampamp401O5 ($Q+

BK3DE DE3DC BK3DE KLC3MLE KLC3MLE KLC3MLE HLE3GLE HLE3ILE HLE3GLE HEE3FEE HEE3FEE HEE3FEE RQS0Aamp$ RQS0Aamp$ RQS0Aamp$ A6$)amp A6$)amp A6$)amp 8+)$ 8+)$ 8+)$

BH3BM KLC3MLE FLE3GLE HEE3FEE RQS0Aamp$ A6$)amp 8+)$

lt3$+ ++)$6)+01A5 J gtLNL01O5 8P$ampamp401O5 ($Q+

BG3DI DI3DM BM3DM KLK3MLD KLK3MLD KLK3MLD FLE3BDLE FLE3BDLE FLE3BDLE DDI DDI DDI

A6$)amp

BF3BM KLK3MLD FLE3BDLE DDI

Bubbling Ponds State13 fish Hatchery13

Bubbling Ponds Fish Hatchery in Arizona does not maintain razorback sucker

broodstock on site Razorback suckers are received either as juveniles from13 Willow Beach

National Fish Hatchery13 or as13 newly-shy‐hatched larvae from13 Dexter13 National Fish Hatchery

Larval fish are13 typically13 placed13 into13 an unfertilized unlined 0613 acre13 pond13 in the13 spring In

September the pond is harvested by draining the pond and seining All fish that have

reached the target size (300 mm TL) are stocked Fish that are too small to stock are split

up equally between the six remaining grow-shy‐out pond at an13 average13 density13 of about 5000

ndash 7000 fish per pond Fish are fed by hand at approximately 25 body weight split

between morning and evening feedings Fish are either fed a catfish diet made by Rangenreg

13

13

that is enriched with spirulina and krill or razorback sucker diet made by Silvercupreg

depending on availability Fish are monitored visually and by sampling using a cast net

When a large number13 of fish have13 grown to13 the13 target size they13 are13 harvested13 by13 draining

the pond and seining13 Fish are again13 sorted by hand and the largest13 fish are stocked13 Fish

that13 have not13 reached the target13 size are returned to the ponds for further grow-shy‐out13 On13

average it13 takes one to two years for fish to reach the target13 size with fish growing13 an

average of 06 mmday Target numbers for production are 12000 razorback suckers

annually (300 mm TL) The biggest difficulty in rearing razorback suckers at Bubbling

Ponds13 Fish Hatchery13 is protozoan13 parasite13 infestations13 (Ich) and13 associated13 bacterial

infections that come from13 an open spring source that is inhabited by mosquitofish

Dexter National Fish Hatchery13

Dexter National Fish Hatchery maintains four separate razorback sucker13

broodstocks13 These fish are spawned on13 site and larval13 fish are placed directly into 01 acre

ponds at a density13 of about 20000 larvae13 per pond (50 ndash 100 thousand13 per13 acre)13 Ponds

are fertilized with alfalfa13 pellets and superphosphate two weeks prior to receiving13 larvae to

produce13 natural13 feed for larval13 fish13 Ponds are13 fertilized again with alfalfa13 pellets one week

after larvae are introduced13 Fish are fed a catfish starter diet13 (sizes 1-shy‐3) made by Rangenreg

that13 is enhanced with spirulina13 and krill13 and then switched over to the razorback13 diet13 once

they are large enough to eat 1mm13 crumble Fish are fed twice a day by hand four days a

week13 at 25-shy‐60 body weight Feed ration is decreased if excess feed is seen remaining

on the13 pond bottom13 following feedings Fish are not graded or sorted during this grow-shy‐out

period Razorback suckers are harvested in the fall by draining ponds completely Fish are

sorted13 at harvest and13 distributed13 to13 other13 facilities13 for further13 grow-shy‐out depending on13

current size requirements Razorback suckers are on average 100 ndash 200 mm TL after the

first growing13 season13 and13 generally13 take13 1 -shy‐18 months for a majority of the fish to reach

300 mm TL There are 16 different species of fish maintained at Dexter National13 Fish13

Hatchery13 and13 having sufficient pond13 space13 to13 grow out separate13 groups13 of fish is the13

limiting factor for production of razorback suckers at this location

14

13

Grand Valley13 Native13 Fish Facility13

The Grand Valley Native Fish Facility maintains its own brood stock13 in13 eight13 ponds

located at the Horsethief Basin Wildlife Area in Grand Junction Colorado Fish are

spawned13 on site13 and13 larvae13 are13 reared13 indoors in fiberglass13 tanks13 at the13 24-shy‐Road13 Fish13

Hatchery13 in Grand13 Junction The 24-shy‐Road13 Hatchery13 consists of two13 separate13 recirculating13

systems that operate using de-shy‐chlorinated13 city13 water13 and two13 large13 fluidized-shy‐ bed sand

filters13 and13 rotating-shy‐drum13 filters for waste removal Fish are held in 4-shy‐foot (n=78) or 8-shy‐foot

(n=14) diameter fiberglass tanks Larval fish are started on prepared feeds immediately

after swim-shy‐up and fed exclusively razorback feeds made by Silvercupreg Fish are started on

a 0-shy‐250 micron razorback diet for the first 10-shy‐1213 days13 and13 then13 fed with13 gradually13

increasing13 feed sizes based13 on observations of feeding13 (250 ndash 400 micron 1 starter) Feed

sizes are mixed when transitioning to the next larger feed size These razorback diets are

specially sifted by Dr Rick Barrows (USDA13 Hagerman experiment station Idaho)

Razorbacks13 are13 typically eating 1mm13 extruded pellets by the time they are 35 to 4 inches

in length Fish are fed approximately 70 body weight per day initially and then gradually

reduced to 15 body weight by the time they reach the 300 mm TL target size Fish are

fed seven days13 a week using13 12-shy‐hr13 belt feeders It takes13 12-shy‐16 months to grow fish to the

target13 size in13 the hatchery13

Razorback suckers are sorted after three months and culled to about 4000 fish per

family lot Culled fish are stocked into leased grow-shy‐out ponds Stocking densities for

juveniles in these ponds is based on previous13 stocking and harvest13 rates13 and is pond

specific13 Grow-shy‐out ponds are13 harvested13 periodically13 using Fyke13 nets13 or trap13 nets13 and13 fish of

the target size are stocked Disease problems (Ich Lernea) water quality problems (low

DO) and difficulty in removing all of the fish are challenges for grow-shy‐out of razorback

suckers13 in these13 natural ponds13

Fish reared13 in the13 24-shy‐Road facility are sorted again at four to five months of age into

small and large size groups to obtain more uniform13 growth rates Batch estimates of fish

weight are done every month for each tank A group of fish are weighed and counted to

give an average weight for the tank with lengths estimated based on a lengthweight chart13

The biggest difficulties13 for growing13 out razorback suckers13 at the13 24-shy‐Road13 Fish13 Hatchery13 are13

insufficient space and water flow (oxygen) to grow fish to the target size At the Horsethief

15

13

Basin13 Ponds where broodstock13 are reared13 diseases such as Ich are problematic because

water is pumped directly from13 the Colorado River

Ouray13 National Fish Hatchery13

Ouray13 National13 Fish Hatchery maintains its own broodstock and13 spawns13 fish on-shy‐site13

Larvae are transferred from13 indoor hatching tanks to unfertilized 02 acre outdoor ponds

and stocked at densities 10000 ndash 20000 larvae13 per13 pond13 Even13 though13 outdoor13 ponds13 are13

covered with13 bird13 netting13 avian predators13 still get caught in the13 nets13 if they13 can see fish

Ponds are dyed blue13 as the13 fish grow to13 prevent avian predation13 While in the outdoor

ponds13 fish13 are13 fed a slow-shy‐sinking salmon diet made by Silvercupreg twice daily by hand

Amount of feed is based on periodic sample counts Fish are grown until late September at

which time temperatures require that all fish13 other13 than13 adult broodstock13 be13 brought

inside for the winter Ponds are drained completely and fish are sorted by hand Fish that

have reached the target size (300 mm TL) are stocked into the Green and Colorado Rivers

All remaining fish are moved indoors13 and13 held13 in three-shy‐foot (n= 30) or eight-shy‐foot (n=27)

diameter circular tanks On average it takes 12 ndash 18 months to grow fish to the 300 mm TL

at Ouray13 hatchery13

Razorback suckers are held during the winter in a recirculating system13 that

operates13 using13 two13 large13 fluidized-shy‐bed sand filters and a rotating-shy‐drum13 filter for solids

removal Fish are fed the Silvercupreg razorback diet using belt feeders There is currently

capacity13 to13 hold13 only13 20000 200-shy‐300 mm TL fish inside the facility and any extra fish13 are13

stocked13 into13 floodplain-shy‐wetlands or used for research purposes13 Ouray no longer leases

any private grow-shy‐out ponds Grow-shy‐out ponds were troublesome due to poor water quality

harvesting13 difficulties13 and13 non-shy‐native13 fish introductions13 The biggest difficulty13 for

production13 of razorback13 suckers at the Ouray13 National13 Fish13 Hatchery13 is space13 during13 the

winter to maintain large numbers of fish and high iron and manganese in the well water

that must be filtered out prior to use

16

13

Willow Beach National Fish Hatchery13

Willow13 Beach National13 Fish Hatchery receives wild-shy‐caught larvae from13 Lake

Mohave Larvae are treated for diseases with formalin and malachite green and placed in

45 ten-shy‐gallon13 flow-shy‐through aquaria13 Recirculated13 solar heated water13 22-shy‐25deg C is used to13

allow production of warm13 water fish at this traditionally cold water facility (Figiel 2003

Figiel et al 2005) Fish are fed brine shrimp nauplii to satiation every hour and after 14

days small amounts of specialized larval fish diet (Encapsulon13 Cyclopeeze13 spirulina13 and

artificial plankton) are introduced After 30-shy‐6013 days13 fish are13 transferred13 to13 six13 32-shy‐gallon13

fiberglass troughs at densities of 1000 to 1500 fish per tank and then a month later moved

outside13 to13 eight recirculating13 raceways that use a combination of well water and solar-shy‐

heated water to maintain temperatures of 22 ndash 25deg C during the summer months

When13 in13 the outside raceways13 fish are fed the razorback13 diet13 using13 belt13 feeders and

fed by13 hand13 at 10 -shy‐ 70 body13 weight per13 day Feed amount is adjusted based on sample

counts according to a feed conversion program13 developed for razorback suckers by Willow

Beach Hatchery personnel This program13 uses length and number-shy‐per-shy‐pound generated

from13 several years of razorback growth data (Figure13 1) Fish are13 sorted13 opportunistically13

and are not handled during the summer months when water temperatures are above 20degC

In 2004 the target size for stocking was 325 mm TL or greater (WBNFH 2004) with a

target13 of producing13 6000 fish per year Reaching this13 target size usually13 takes13 two13 growing13

seasons13 The biggest difficulty13 in rearing13 razorback suckers13 at Willow Beach13 National Fish

Hatchery13 is insufficient space13 to13 grow fish to13 increased13 target sizes (400-shy‐500 mm TL)

Uvalde13 National Fish Hatchery13

Uvalde13 National Fish Hatchery13 in Texas13 receives 35000 ndash 60000 razorback sucker13

fry annually in MarchApril from13 Dexter National Fish Hatchery The fry are acclimated in

bags submerged in the pond for a minimum13 of one hour and released into13 a 1 acre13 fertilized13

pond where they are reared for the remainder of the summer Fingerlings are fed a starter

razorback diet when they reach approximately 50 mm TL In AprilMay the previous year

class of razorbacks are captured from13 their over-shy‐wintering pond enumerated graded and

split into13 one-shy‐acre grow-shy‐out ponds Approximately 4000 ndash 5000 fish will be13 placed13 in each13

one acre pond for summer grow-shy‐out Fish are reared for approximately 150 days (May ndash

17

13

Oct) and fed the Bozeman razorback diet two times a day five days a week at 15 ndash 30

body weight per day based on average water temperature

Figure 1 Relationship between length and number of fish per pound

In general13 juvenile razorback13 suckers (received as fry13 during13 the previous spring)13

reach the target size of 300 mm TL in approximately 6 months In 20062007 Uvalde

produced 6000 razorback suckers 300 mm TL for introduction into the San Juan River

Starting13 in 2008 Uvalde NFH will be producing13 and distributing13 12000-shy‐ 300 mm TL

razorbacks for stocking into the San Juan River Predation from13 migrating cormorants has

occurred but timing of harvest and over wintering protection methods such as covering

ponds with netting or placing fish indoors helps to minimize losses during the cormorant

migration (November to March) Uvalde has experienced razorback mortalities because of

bacterial problems but these are usually resolved through the use of oxytetracyline

medicated feed

Overview13 of Differences in Culture Methods

Several differences were noted when conducting surveys at each of the five main

production facilities for razorback sucker (See Appendix 3) These differences include

different stocking13 and13 rearing13 densities13 (Table13 4-shy‐5) various feeding regimes and type of

18

13

lt=amp

feeds (Table 7) as well as differences in grading or sorting practices Some of these

differences are13 related13 to13 whether13 or not razorback suckers13 are13 being13 reared13 in extensive-shy‐

culture13 facilities13 (ponds) or intensive-shy‐culture13 settings13 (raceways13 o tanks)13 Some13 practices13

are unique to a single facility13 or a couple of facilities (Table 6)13 Managers at each facility13

were asked to identify the biggest13 difficulty or constraint13 that13 they experience when13

growing-shy‐out juvenile13 razorback suckers13 at their13 respective13 location13 Space constraints13

water quality and disease problems were the main factors limiting production of razorback

suckers13 at these13 facilities13 (Table13 8) Calculated or reported growth rates from13 the literature

vary widely (Table 9) and range from13 02 to 18 mmday These growth rates indicate that

juvenile razorback suckers have a very high growth potential under optimal rearing

conditions13

Table13 4 Stocking13 densities13 for larvae13 and13 fry in ponds

$amp( )(+amp-( 01-2(3(4amp56( 4amp56(+amp-( 01-2782-( $amp () + --amp +amp0amp)+amp 12-3amp ( )+amp0amp+amp --amp +amp0amp)+amp 42556789amp8 ( +amp0ampgt+amp 3amp +amp0amp+amp A-BC-Damp (E + 3amp )+ F-6ltamp ) G+ 3amp G+

Table13 5 Rearing13 densities13 at intensive13 culture13 facilities13

$amp( )amp+(($-( $0( 12(3$+( 40((amp05( 67((amp05( 8$9(407$( $amp amp())amp++-$amp 0 1 0amp2amp1amp 3amp2amp4 0544

6amp())amp++-$amp 610 021 4amp2amp47amp 3amp2amp77amp 058 9$amplt+)amp 4amp())amp++-$amp 00 1 7amp2amp77amp 851amp2amp0amp 05

6amp())amp++-$amp 610 77amp2amp1amp 0amp2amp1amp 053

19

13

Table13 6 Rearing13 practices13 that are13 unique to13 specific rearing13 facilities13 $$amp( )$+-(amp$-(0(1-amp2034( $amp()amp+( -0$(12(33+(amp(amp134$53+(amp$amp3+(6amp+(

723(843(1$8(422(6amp+(42amp(4(423(19$43( 343( lt34$53(6amp+(6(4($03(amp4+94amp(842($1$1(63$$34(amp+(63626243( =amp+(gtamp94ampA( B3(1(1$+53+C3+(amp+(1$43(1(3D0$(1(amp443(amp+(amp443( 734231(amp( B3(1(193(44(1(34amp(amp(+49E(6amp+( -E3(F3+( G3amp(1(12(amp(H3(13$(4ampE(C(IJK($$amp( A( L43(+A3(4(6303amp4(63+4ampM(66$3D3amp4$(34amp(amp(6amp+(C((4amp3( L$$8(392(

B0$+3(

N43D(13+(4($0$(12M(amp+(639$53+($0$(12(+34( G3amp(12(amp(399$4amp(4+(938A(842($(2343+(843( N443D643+(3amp(12(amp(amp34(63amp(amp(423(O$+(G03( )amp+(3(134$53+(6(4(39364(1(1A(4(44(423D(amp((D3(amp4$(+34(

Table13 7 Types of feed used at razorback sucker13 hatcheries13 $amp ()amp+-amp0- $$)1amp23 45-amp)-$5)1amp23 $amp()amp+( -amp$amp+(amp+( -amp012$3+(amp+4(amp5215$(0+( 65ampamp7(85209(+2($1(87((15315lt=(+2(

+amp+amp(amp(55$5$2gt( 21( Aamp+(amp+( )amp+(012$3+(B29(5$05$95($$2(5amp+(

199524(amp5215$(0+( 65ampamp7(85209(+2($1(87(15315lt=(+2(amplt( 29gt(51($51(amp9(2(25=(C(DD(0+(

E15amp+(Famplt2amp( G1$5(lt1lt$51(25amp=( HIJKH(Dlt1amp(15315lt=(+2(I(C2(CH(+5gt( )11$gt($511(02+(15315lt=(+2(

$1(87(15315lt=(+2(D5$$(3(lt5$$gt(02+(gt( 6lt=(511B(

L15gt( G1$5(lt1lt$51(25amp=(Aamp+( amp+(

HIJKH(Dlt1amp(15315lt=(+2(I(C2(CH(+5gt( )11$gt($511(02+(15315lt=(+2(

$1(87(15315lt=(+2($1(87($B(amp=amp( 5$Damp(+2(

M$$B(5lt9(-5$+( NO515(G1$5(219( L2+1(15ltB5gt(Aamp+(5amp+( amp$amp+(amp+(

1amp(91D(amp5$(Pamplt5$amp4( 8gtlt$34(1$amp54(5amp+(5120lt5$( $5amp=2amp()amp+(012$3+(B29(5$05$95( $$2(5amp+(19952Q(amp12152( 1+lt2amp(

$1(87(15315lt=(+2($1(87(15315lt=(+2( $1(87(15315lt=(+2(

Table 8 Factors limiting production at major razorback sucker facilities

$amp( )amp+(-0+1((2$(0amp1ampamp(-34amp( $amp()amp+( -(01$2(34+(546(amp(0amp(01amp(541(13( -741( 803(3amp41amp4(9((+ltlt1amp4(03(amp(44amp(2=(4(

+ltlt3$4(4(2amp4amp(014(1gt13=(43=( 1amp+(amp34amp( 803(3amp41amp4(1$4+(4(541(A$4B(amp+(+$C+(

7Bamp($244amp(lt(1313$4amp(B42( D1B( E41(A$4B(01$2(3+(B(66(1amp(amp+(2ampamp(

Eamp41(420141(464(1A1($$(lt6(4((2C+(amp+1( 803(3amp41amp4(1$4+(4(541(A$4B(amp+(+$C+(7Bamp(

E$$5(36( 803(3amp41amp4F(15amp(lt6(4(amp31amp$B($11(gt( 1$4(amp(ampltlt3amp4(03(amp(44amp(lt1(amp5(lt6(

GC$+( 8221(420(3amp(4(6691A1amp(051((4(410$(+(4( 661(1amp+541(020amp(4(=0(0amp+(3$F(

20

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Table9Reportedandcalculatedgrowthratesfromtheliterature

Calculatedgrow

thratesbasedon

informationprovidedinliterature

aApproximationsofmaximum

grow

thpotential(basedon

average13 maximum

sizesiffishreportedatharvest

21

13

General Information on Factors that Affect Fish Growth

Growth in fish is extremely variable and is impacted by many different

physiological and environmental factors Growth rates are known to change with size and

age sex season activity level density amount13 of living space quality and quantity of food

genetics and temperature (Brett 1979) Growth experiments conducted at different times

of year can result in growth rates that are not comparable As fish become larger their

physiological13 potential to grow decreases making determination of growth rate dependent

on the size of the starting fish and the length of the experiment (Busacker et al 1990)

Genetic factors also have great potential to influence growth rate Some species have

strains13 and13 races13 that display vastly different growth potentials (Reinitz et al 1979) All of

these factors combine to make assessment of the individual factors controlling fish growth

difficult13

Water temperature is probably the most important variable affecting growth rate13

All of the basic functions that affect growth such as feeding digestion and metabolism are

temperature-shy‐dependent13 Growth13 is inseparably13 tied13 to13 bioenergetics13 and13 therefore13 also13

tightly tied to temperature When temperatures are below optimum daily temperature

fluctuations can stimulate growth Photoperiod is also commonly linked to water

temperature and can influence growth rates in fish (reviewed in Brett 1979)

Fish density13 is known to13 affect growth13 and13 can alter13 growth13 rates13 in several ways13

Fish that exhibit strong territorial behaviors13 or natural schooling tendencies13 will

experience reduced growth if densities are too high or too low (Brett 1979) Dominance

hierarchies where some fish feed more aggressively than others can also lead to high

variability13 in growth13 rates13 (Koebele13 1985) Crowded13 conditions13 also13 cause physical

interference13 between13 fish and13 poor water13 quality13 which13 reduces13 growth13 (Busacker13 et al13

1990) The effects of fish numbers space and feeding opportunity are frequently correlated13

and often13 difficult13 to distinguish (Brett13 1979)13

It is impossible to study the effects of environmental factors on growth without also

evaluating feed rations (Brett 1979) Amount of food quality of the diet particle size

number of feedings per day and time of feeding have all been shown to affect growth

(Busacker et al 1990) In controlled laboratory studies food is usually fed ad libitum13

22

13

(constantly available) and other variables are altered to assess impacts of environmental

factors13 on growth13 These studies13 are13 usually13 conducted13 in tanks13 or raceways13 because13

researchers must verify that food is constantly available to the fish which is difficult to do

in large pond environments where the fish and the bottom13 are often not visible (Busacker13

et al13 1990)

Specific Information13 o Razorback13 Sucker13 Growth

Variable13 growth

Growth in razorback suckers is naturally highly variable and may be a function of

their evolutionary history (USFWS13 2002)13 Minckley (1983) speculated that13 wide size

variation in a single cohort of razorback suckers may be adaptive with fast-shy‐growing13 fish

that13 reproduce at a young13 age surviving13 better in13 high discharge years and slow-shy‐growing13

smaller fish surviving better during drought periods This highly variable growth rate

makes rearing razorback suckers in a production setting difficult because fish from13 a single

cohort do not reach the target stocking size simultaneously One of the major tasks for

aquaculture is to maximize both individual growth and total production13 (Gerking13 1978)13

This becomes more difficult when the species being cultured exhibits highly variable

growth13 rates13 because of genetic influences as is the case with razorback13 suckers13

Razorback13 sucker growth13 is typically very13 rapid13 during13 the first13 year of life13 and then13

declines with age First year growth can be as low as 50 mm and as high as 350 mm (Valdez

et al13 1982 Minckley13 1983 Mueller13 1995) Razorback sucker13 grow rapidly13 for

approximately the first five or six years of life and then growth slows13 (McCarthy13 and13

Minckely 198713 Tyus 199813 Minckley et13 al 1991)13 Growth of older individuals in13 extant13 wild

populations is very13 low (Minckley 198313 Tyus 198813 Modde13 et al 1996)13 Wild growth13 rates

for mature adult fish in Lake Mohave based on PIT tag recaptures were often too small to

be accurately measured for both males and females over the time period of 1987-shy‐199713

(Marsh and Pacey 1998) This information suggest it will take substantially longer to rear

fish to13 increasingly13 larger13 stocking13 sizes (40013 ndash 500 mm TL) than it did to reach the target

size of 300 mm TL

Growth in ponds

23

13

One of the main strategies for maintaining genetic refugia and self-shy‐sustaining13

populations of razorback13 sucker in the lower Colorado13 River basin13 is to rear razorback13

sucker13 larvae13 in production13 ponds until they13 are13 a suitable13 size for stocking13 (USFWS13 2004)

Pond culture has proven useful to promote rapid growth of juvenile razorback suckers

(Kaeding and Osmundson 1989) Marsh (1994) reported that growth rates of razorback

suckers13 reared13 in golf-shy‐course13 ponds exceeded13 the13 best growth13 rates13 obtained13 under

intensive13 culture13 conditions13 at federal hatcheries13 especially13 during the13 first several years13

of life Growth rates in these semi-shy‐natural ponds are also comparable to estimated growth

rates13 of juvenile13 wild13 fish (McCarthy13 and13 Minckley13 1987) Modde13 and13 Haines13 (2005)

reported13 the13 greatest growth13 rates13 in the13 largest and13 deepest floodplains13 with13 the13 greatest

amount of submergent vegetation but excellent growth and survival of fish in a grow-shy‐out

pond is of little value if there is not an efficient way to collect the fish from13 the pond

(Kaeding and Osmundson 1989)

Temperature13

Bulkley and Pimentel (1983) used shuttle boxes in the laboratory to determine a

temperature preference13 for razorback suckers13 of 23-shy‐24degC13 In13 their13 studies13 razorback

suckers were found to avoid temperatures below 118 degC or above 286 degC Razorback

suckers at Bubbling Ponds Hatchery are more active in the spring and feed better as

photoperiod increases even prior to water temperatures rising (Frank Agygos personal

communication) Table 3 briefly summarizes water temperature data from13 each facility

Detailed seasonal water temperature profiles are not currently available for many

razorback grow-shy‐out sites13

Density13

Extensive studies have been conducted on commercially important species to

evaluate stocking densities and feeding rates that maximize production For these species

controlled experiments under laboratory conditions have established relationships

between temperature density and feed ration on growth (Brett 1979) but this information

is sporadic13 or non-shy‐existent for razorback suckers13 (Bays13 et al13 2005) Fish culturists13 with13

24

13

experience13 rearing13 razorback suckers13 typically13 have13 target stocking13 densities13 that13 they use

(Tables13 4 -shy‐ 5) These stocking densities have largely been determined over time by trial

and error These approximate stocking densities provide a good starting point for more

controlled13 types13 of replicated13 pond studies13

Feed ration

Razorback13 suckers are currently13 being13 fed a wide variety13 of prepared diets (Table 7)

that range from13 a slow-shy‐sinking salmon feed manufactured by Silver Cupreg to a spirulina

and krill-shy‐enhanced catfish feed made by Rangenreg Most locations are feeding 20 ndash 50

body13 weight per13 day13 Methods13 for culture13 of razorback sucker13 larvae13 in intensive13 settings13 at

fish hatcheries are well documented (Figiel 2005) and various larval fish diets have been

evaluated13 (Tyus and13 Severson 1990 Severson et al13 1992) but no standardized13 procedures

are used for feeding13 larval13 fish in13 intensive settings13

Razorback sucker larvae are also effectively reared in pond environments using

natural foods supplemented with larval fish diets and survival is high when no predators

are present13 (Mueller 2006)13 Growth rates for larval13 and early juvenile razorback13 suckers

may increase with pond fertilization Diet and physiological studies on wild razorback

suckers indicate that they feed on plankton as well as benthic organisms during their entire

life (Marsh 1987) Artificially fertilizing ponds may greatly increase production capacity

and growth rates for razorback13 sucker (Papoulias and Minckley13 1992) and warrants

further13 investigation13

Handling stress

Handling stress13 has13 been shown to13 influence growth13 rates13 Paukert13 et al (2005)

found that growth of bonytail chub was reduced by 26when compared with controls

after being13 repeatedly13 captured and handled in13 hoop13 nets13 Handling13 effects are likely13 to be

similar for razorback suckers that are repeatedly13 captured and sorted in13 a hatchery13 setting13

Razorback suckers that are handled at Willow Beach National Fish Hatchery will commonly

not eat for two weeks after handling (John Scott personal communication) This creates a

difficult situation13 for production13 facilities because13 fish13 need to be sorted to ensure13 large13

25

13

aggressive fish do not interfere with growth of smaller individuals but frequent handling

and sorting13 causes stress related reductions in13 growth13

Measuring Growth in Captive Fish

Weight is the traditional measure used to estimate growth or production in

aquaculture settings13 Groups of fish are typically13 weighed and an average individual13 weight13

is computed (Busacker et al 1990) Although this method is often logistically the easiest it

may not be the most informative for species with highly variable growth rates like

razorback suckers especially when target lengths must be reached before fish can be

stocked Weight can also be highly influenced by things like stomach fullness or

development of gonads (Busacker et al 1990) Condition factor or relative weight can also

be used to assess growth of fish but these tools may be more robust predictors of fecundity

than of growth (Anderson and Neuman 1996) For some species sexes need to be

distinguished because males and females may differ in morphology (Anderson and

Neumann 1996) Mueller (2006) analyzed growth rates based on PIT tag recaptures of 86

razorback suckers13 in High13 Levee Pond13 and13 found13 that differences13 in growth13 do not appear13

to occur until fish are over 450 mm TL at which time growth rate in males slows while

females continue to grow at a slightly higher rate This would indicate that sex may not be

an important factor to consider when examining growth rates unless the target grow-shy‐out

size is above 450 mm TL

The best measures of growth are often determined from13 the length and weight of

individuals rather than from13 groups of fish (Anderson and Nuemannn 1996) because

individual growth rates give better estimates of confidence and variance (Busacker et13 al

1990) Length frequency analysis or recapture of previously marked individuals of a known

size is likely to yield the most useful information for razorback sucker growth The success

of any of these methods depends on proper sampling procedures that are representative of

the population as a whole (Busacker et al 1990) Sampling methods that are known to be

size-shy‐biased such as trammel nets (Mueller et al 2004) or cast nets should not be used when

trying to measure growth rates13

26

13

Conclusions

For razorback sucker survival is largely associated with stocking size Additional

focused13 research13 is therefore13 needed to13 identify13 ways13 to13 increase13 growth13 rates13 of captive-shy‐

reared13 razorback sucker Growth13 rate13 in fish is controlled13 by many factors including fish

size and age temperature density and feed ration which can all be highly correlated

Growth of razorback suckers is also inherently variable which makes the task of identifying

the key factors that13 affect13 growth in13 captivity even more difficult The focus at most

razorback rearing facilities13 is production so the13 types13 of data that are13 collected13 are13 often

insufficient for detailed13 evaluations13 of individual rearing13 practices13 on growth13 Surveys of

existing13 razorback sucker13 rearing facilities indicate that culture methods vary widely and

the types of growth data13 that13 are collected are not13 standardized13 Replicated studies with

detailed information on rearing location water temperature initial stocking size stocking

density and the sizes of all fish at harvest are needed in order to compare the effects of

individual rearing practices on growth This type of research will ultimately provide both

time and cost-shy‐savings to production facilities by reducing the amount of time necessary13 for

razorback sucker to reach stocking size improving overall production efficiency

Optimum13 rearing densities for razorback sucker larvae and juveniles remain to be

determined Current stocking densities will be very useful as starting point for more

detailed studies and although optimum13 rearing densities are likely to be site-shy‐specific13

replicated studies on density will provide a valuable reference for hatchery managers

Frequency13 of sorting is another13 area that needs13 further13 research Frequent

handling13 and13 sorting13 can13 cause13 stress-shy‐related13 reductions13 in growth but not sorting can

create dominance hierarchies that further reduce growth rates of subordinate individuals

The effects13 of sorting13 on overall fish growth13 in both13 pond and13 intensive13 culture13

environments warrant further investigation Research techniques for these types of

experiments are well understood and typically utilize a matrix of replicate ponds per

variable (Bays et al 2005) In every case accurate and complete records of sampling

procedures and data collection are needed in order to interpret data and make inferences

about13 growth rates (Busacker et13 al 1990)13

27

13

Additional research is also needed to evaluate long-shy‐term13 survival of stocked fish

reared in ponds compared to fish13 reared13 in intensive13 culture13 facilities13 Exercise13

conditioning13 and predator-shy‐recognition training may also increase survival of stocked fish

and be more economically feasible than rearing fish to increasingly larger sizes prior to

stocking13 The success13 of traditional fish hatchery programs is measured largely by the

number of fish stocked but hatchery programs for endangered species must measure

success in terms of long-shy‐term13 survival and species recovery (Brannon 1993 Anders 1998)

A specific list of research recommendations follows

Specific Research13 Recommendations13

bull Use replicated studies13 to establish optimum stocking13 densities13 for ponds13 and

tanks13 that can be used as13 a starting13 point for site specific refinement

bull Determine if sortinggrading13 improves13 overall growth rates13 in both ponds13 and

intensive culture facilities13

bull Investigate the use of artificial fertilizers13 to improve growth of both juvenile

and adult razorback suckers13 in ponds13

bull Determine if the razorback sucker diet gives13 better growth rates13 than cheaper

catfish or salmon feeds

bull Evaluate growth rates13 and production potential of new intensive culture

methods13 such as13 large circular tanks13

bull Evaluate13 long-shy‐term survival of fish produced from raceways13 and circular tanks13

compared to fish reared in ponds13

bull Evaluate more effective means13 of treating13 fish diseases13

bull Evaluate factors13 other than size that may increase post-shy‐stocking13 survival such

as13 exercise conditioning13 predator recognition training or rearing13 under more

natural settings13

28

13

II The Effect of Disease Treatments on Razorback Sucker

Growth

Section13 SummaryFormalin copper sulfate potassium permanganate and13 salt are all chemicals commonly13 used13 to13 treat13 Ichthyophthirius multifiliis outbreaks in captive razorback sucker (Xyrauchen13 texanus) Weexposed 190 juvenile13 razorback suckers (127 ndash 26 mm TL) to13 5 5-shy‐day treatments with13 each13 chemical to evaluate the effects13 these chemicals13 may have on growth Fish grew an average of23513 mm TL13 during the month13 study period Fish treated with formalin grew on average13 29mm TL (03 mmday) while fish treated with copper had the lowest growth averaging 20 mmTL (021 mmday) No significant differences in13 growth were observed among fish treatedwith any of the chemicals compared to untreated fish (pgt005) Reductions in growth13 as aresult of repeated chemical treatments are not likely the cause of differences in growth ratesamong13 facilities that raise razorback suckers Repeated chemical treatments may13 have otherimpacts to overall13 fitness or long-shy‐term survival but13 these effects were not13 evident13 in our study

29

13

Introduction

Preservation13 of razorback sucker13 (Xyrauchen texanus) currently13 depends on captive13

rearing and stocking programs until permanent solutions to factors that prevent wild13

recruitment are found Low survival of stocked razorback suckers (Brooks 1986 Marsh

and Brooks 198913 Marsh and Pacey13 2005) has caused target13 sizes for stocked fish to

steadily increase in efforts to reduce predation mortality (Marsh et al 2005 Schooley and

Marsh 2007) Rearing fish to larger sizes at hatcheries comes with increased costs and

creates the need to evaluate husbandry and rearing practices that may affect fish growth

Formalin copper sulfate potassium13 permanganate and salt are all chemicals

commonly used at razorback sucker rearing facilities to treat outbreaks of the protozoan

parasite13 Ichthyophthirius multifiliis ldquoIchrdquo is one of the most pathenogenic diseases of

cultured13 freshwater13 fishes (Matthews13 2005) and causes large13 losses in captive13 populations13

of endangered razorback sucker Each of these chemicals used to treat Ich only kill the free-shy‐

swimming life stage of the parasite13 requiring13 repeated doses over several13 days depending13

on water temperature These chemicals treatments are needed to prevent loss as a result

of disease outbreaks but the cumulative effects repeated disease treatments have on

growth13 are13 unknown

Copper13 sulfate13 has13 been shown to13 significantly13 reduce13 growth13 of channel catfish13 in

production13 ponds (Rabago-shy‐Castro13 2006) but it is unknown whether13 razorback suckers13

experience similar reduced growth following copper treatment Quantifying the impacts of

disease treatments on growth will help to interpret the wide differences in growth rates

observed13 at various13 razorback sucker13 production13 facilities13 throughout the13 southwest

(Ward et al 2007) If one chemical is found to have less detrimental impacts on growth

than another then it may be preferred for use as a disease treatment We evaluated growth

rates13 of razorback suckers13 under13 replicated13 and13 controlled13 conditions13 to13 assess13 effects13 of

repeated formalin copper sulfate and potassium permanganate and salt treatments on

growth13

Methods

We captured 190 juvenile razorback suckers from13 ponds at Bubbling Ponds Fish

Hatchery AZ using hoop nets or cast nets All fish were of the same age class and

30

13

averaged 179 mm total length (TL) (range13 = 127 ndash 262 mm TL)13 These fish were13 offspring13

of captive13 razorback sucker13 broodstock held13 at Dexter13 National13 Fish Hatchery13 NM13 (2007

year class) All fish were tagged with passive integrated transponder (PIT) tags and

quarantined for one month prior to the experiment to allow fish to recover from13 tagging

and become accustomed to being held in circular tanks

At the beginning of the study all fish were weighed measured and scanned for

individual tag numbers with 19 randomly selected fish placed into each13 of 10 8-shy‐foot

diameter circular tanks (Figure 2)13 Each13 tank contained13 two13 airstones13 and13 an13 individual

biofilter with a recirculating water pump (31 litersminute) that had been operating for

at least 1 month prior to the experiment to allow bacterial colonies to become

established Two tanks were designated as a control and did not receive any chemical

treatments while the other eight tanks received formalin copper sulfate potassium13

permanganate or salt treatments at two week intervals (two tanks per chemical

treatment) Formalin copper sulfate and potassium13 permanganate were treated at 1 part

per million (ppm) and salt was applied at 30 parts per thousand (ppt) These treatment

rates are commonly used to treat13 razorback13 suckers for ich at Bubbling13 Ponds Fish13

hatchery (Frank Agygos personal communication)

Figure 213 Photo ofexperimental tankswith individualbiofilters and aeration

31

13

Each treatment consisted of a series of doses applied on Wednesday Thursday and

Friday with a 90water change between each dose Biofilters were removed from13 all

tanks and held in a separate holding facility during treatments and then replaced on the

Monday following treatments after a 90water change This schedule allowed fish to be

exposed to chemical treatments for 5 consecutive days without water quality deteriorating

This 5-shy‐day chemical treatment was repeated every two weeks from13 July to October (97

days)13 for a total of 5 5-shy‐day treatments Water temperature in the treatment tanks ranged

from13 13degC (55degF) to 32degC (91degF)

Fish were fed a fixed ration of commercial razorback diet (Silvercup 4mm13 pellet)

once daily13 (2 percent body13 weight per day13 as calculated13 by13 average initial fish weight)13

At the end of the experiment all fish were again weighed measured and scanned for

individual tag numbers Growth of fish in each treatment group was compared using

analysis of variance (ANOVA) Any mortalities13 that occurred during the13 study13 were13

replaced with previously quarantined fish of equivalent size to maintain equal densities in

each13 tank13 but growth13 data was13 only13 recorded for fish which13 survived13 the13 entire13

experiment

Results

Fish at the13 start of the experiment averaged 179 mm TL (Range13 = 127 ndash 262 mm)

with no significant differences in fish length among treatment groups (F(4189) = 00183 p

gt 0999 ANOVA) On average fish grew 235 mm TL (024 mmday) during the 3 month

study13 Fish in tanks13 treated with formalin had the highest growth averaging 29 mm TL (03

mmday) while fish in tanks treated with copper had the lowest growth averaging 20 mm

TL (021 mmday) Fish in the control tanks averaged 213 mm TL in growth (022

mmday) (Figure13 3)13 Formalin-shy‐treated fish grew13 significantly faster than13 any other

treatment group but no13 significant differences in growth13 in length13 or weight were13

observed among fish treated with any of the chemicals compared to untreated (control)

fish (pgt005 ANOVA)

32

13

Figure 313 Average growthof razorback suckersexposed to a series of 5 5-shy‐day chemical treatmentsover a 97-shy‐day13 periodError bars representstandard error

Discussion13

Growth13 rates13 observed13 in our study13 (021 ndash 03 mmday) are low compared to those

reported13 in other13 studies13 of razorback sucker13 growth13 (0213 ndash 18 mmday) (Ward et al

2007) Using recirculating water systems for our study required filters to be removed and

replaced during treatments Stress to fish caused by removing and replacing filters within

the tanks as well as repeated water changes may have led to overall higher stress and

reduced growth rates compared to those reported for unconfined fish Growth in fish is

highly variable and is affected by many different physiological and environmental factors

including fish size density temperature amount of space and food (Brett 1979) We

strived to control each of these factors but other factors may have also influenced growth

in our experimental tanks During mid-shy‐summer water temperatures in the treatment

tanks reached 32degC (91degF) At these warm13 temperatures fish are very susceptible to

bacterial13 infections13 The slightly higher growth exhibited by fish in the formalin and

potassium13 permanganate treatments may have been the result of these two chemicals

33

13

being effective at controlling bacterial infections The differences in growth we measured

among treatment groups were not statistically significant and do not appear13 biologically13

meaningful during the relatively short duration of this study (97 days) although the

cumulative effects of slightly reduced growth could be biologically meaningful over longer

time frames

Reductions in growth13 as a result13 o repeated chemical treatments are not likely the

cause of differences in growth rates among facilities that raise razorback suckers

Repeated chemical treatments may have other impacts to overall fitness or long-shy‐term13

survival but these13 effects13 were13 not evident in our study It is more likely that the parasite

outbreaks themselves are the cause of different growth rates among razorback rearing

facilities rather than the chemical treatments used to treat the parasites We recommend

that hatchery managers continue to use the chemicals that are most effective at controlling

ldquoIchrdquo13 at their individual13 facilities

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower Colorado Rive Multi-shy‐species13

Conservation Plan under Work Task C10 We thank Ty Wolters and Tom13 Burke for their

support of this research and Frank Agygos and Dave Billingsly of the Bubbling Ponds Fish

Hatchery13 for their13 technical assistance13 and13 help with13 collecting13 fish

34

13

III13 Razorback Growth Rates at Bubbling Ponds ndash 2009-shy‐2011

Section13 SummaryExperimental studies at Bubbling Ponds Fish Hatchery AZ have strived to understand

factors that affect razorback sucker growth in captivity and identify ways to improve growthrates and maximize size at release Rather than performing experimental studies that wouldrequire major13 rearrangement (and likely reduced production)13 of hatchery operations our13 studies13 used normal variation in production techniques13 and practices13 to isolate factors13 thatmay modify growth rates

Our initial work identified razorback13 growth rates in13 lined ponds at standard fishdensity as 026 to13 028mmday (789 to 843 mmmonth) No significant differences in growthrate were observed among fish that had been in the pond only during the winter13 periodcompared to fish that had been in the pond the entire year indicating that water temperatures13 at Bubbling Ponds are high enough to allow fish to incorporate feed effectively year-shy‐roundHowever these growth rates are lower than most values reported from the literature fromnatural or semi-shy‐natural pond environments No significant differences in13 growth rate wereobserved13 between large and13 small fish13 within the 150 ndash 29 mm TL13 size range Additional worksuggests13 that razorback suckers13 tagged at over 300 mm TL had reduced growth rates (024mmday 73 mmmonth) as would be expected according to a typical Von13 Bertalanfy growthcurve although growth rates13 were only slightly less13 than the average growth rate for thehatchery (027513 mmday 82513 mmmonth)

Sorting13 to13 separate small fish from large fish after the first year of growth is practicedesigned13 to allow smaller fish to ldquocatch uprdquo to larger fish We found that13 this technique doesappear to13 improve growth rates of smaller fish Growth rates of sorted small razorback suckers(029 mmday 87mmmonth)13 were equal to that13 of larger13 fish (028 mmday 8413 mmmonth)indicating that sorting may have helped to offset their original slower growth trajectory

Bubbling Ponds Fish Hatchery grows razorbacks in 6 long deep ponds lined with heavyplastic 2 long deep13 earthen13 (unlined) ponds and three wide shallow earthen ponds The wideshallow ponds13 have historically produced very large fish at low density but have been found tomaintain much lower fish numbers than deeper ponds We found13 that growth13 rates ofrazorbacks kept at high density (4-shy‐700013 fish)13 in a wide shallow pond grew extremely slowly(024 mmday 726 mmmonth) This growth rate is among the slowest of any fish over theyears of our study and demonstrates that13 though the large ponds may produce large fish at lowdensity13 they are unable to overcome high13 fish13 densities

Finally one of the major factors influencing13 fish13 growth13 in hatcheries is disease onemajor summer-shy‐time disease at13 Bubbling Ponds is the ectoparasite Ich (Ichthiopthirusmultifiliis) To investigate the impact Ich has on razorback growth we eradicated fish from thespring and water conveyance ditch that supplies13 water to the hatchery using Rotenone This13 restoration effort was fairly short-shy‐lived (Ich returned to the hatchery within four months) but

35

13

growth13 rates of fish13 reared for four months without Ich present (031 mmday 92 mmmonth)were significantly higher than the following 8 months of growth for those same fish (022mmday 65 mmmonth) This disease-shy‐free growth rate is in fact faster than any13 otherprevious growth rates observed at the hatchery in our study

We conclude that growth rates at the Bubbling Ponds Fish Hatchery are likely as highas possible given the pond densities required to13 meet production goals and the Ich-shy‐infestedwater13 that feeds the facility Sorting practices are successful in helping as many fish as possiblereach stocking length as fast as possible Unlined ponds may be able to grow large fish at lowdensities but whatever factors allow for that growth13 are not able13 to overcome13 high fish densityThus the large lower ponds at Bubbling Ponds may be better utilized via renovation to13 deepenand line them

Disease is the most important factor limiting growth as may be expected to be the caseat many13 hatcheries While the spring renovation was not13 a complete success13 the dramaticreduction of fish populations in that habitat was enough to dramatically13 reduce13 the13 occurrenceof Ich at the hatchery13 Such open spring13 systems feeding a hatchery are a misfortune that canbe expected to transmit disease so we suggest that renovating the spring again to combat13 IchImproved techniques to divert water from13 the springs and more throuough treatment ofstream-shy‐side vegetation may improve the success of chemical treatment Successful renovationwould likely both improve growth rates and reduce chemical costs associated with treating Ichoutbreaks Even13 if complete renovation13 is impossible or impractical an13 effort to reduceinvasive fish density in the springs13 which act a vector for the parasite(and thereby reduce thelikelihood of13 Ich being transmitted into ponds) may still13 show dramatic improvements

36

13

Introduction

Conservation efforts13 for razorback sucker13 (Xyrauchen texanus)13 currently13 depend on

captive rearing and stocking programs Low survival of stocked razorback suckers (Brooks

1986 Marsh13 and13 Brooks13 1989 Marsh13 and13 Pacey13 2005) has13 caused13 target sizes for stocked13

fish to steadily increase in efforts to reduce predation mortality13 (Marsh13 et al13 2005

Schooley and Marsh 2007) Rearing fish to larger sizes at hatcheries comes with increased

costs and creates the need to evaluate husbandry and rearing practices that may affect fish

growth13 We evaluated growth13 rates13 of individual razorback suckers13 in ponds13 at Bubbling

Ponds Fish Hatchery13 using Passive Integrated13 Transponder (PIT) tags13 to13 obtain13 precise

growth information for individual fish so that valid comparisons of growth rates as related

to rearing practices can be made

Due to the critical nature of the razorback sucker stocking program we did not

design experimental studies that would require major rearrangement and potentially

reduce production of hatchery operations Instead our studies used normal variation in

production techniques and practices to isolate factors that may modify growth rates

Though this methodology dramatically limits replication and may limit our ability to

directly13 attribute13 differences in growth13 rates13 to13 the13 variables13 we13 investigate13 we13 were13 able13

to accomplish research goals without altering hatchery operations or impacting

production

From13 2009 through 2011 we conducted a series of observational13 growth13 studies to

determine growth rates of individual razorbacks at Bubbling Ponds The first set of

experiments included13 identifying13 growth13 rates13 in lined13 and13 unlined13 ponds determining

growth13 rates13 of fish at different13 sizes13 in13 relation13 to sorting13 practices and monitoring

razorback growth rates after removing the source of the ectoparasite13 Ich (Ichthiopthirus

multifiliis) from13 the hatchery water source13

Razorback growth rate in lined ponds

Our first growth study documented individual growth rates at normal density in 11

million gallon lined ponds13 over two13 years13 This is the standard13 grow-shy‐out process for

razorbacks13 at Bubbling Ponds We monitored growth of fish for a variety13 of sizes and13 the13

37

13

amount of time in a pond during the growing season These13 data give a snapshot of growth13

rates13 at the13 facility13 and13 provide13 the basis for comparisons throughout our study

Growth rate13 in an unlined pond

In addition13 to 6 ponds lined with heavy plastic13 sheeting13 Bubbling Ponds Fish13

Hatchery maintains two narrow and deep (same dimensions as lined ponds13 Figure13 4)13 and13

three large13 shallow unlined ponds These earthen13 ponds typically have vegetation and

associated aquatic invertebrates that may better simulate natural environments by

providing cover and improved food diversity or quality Therefore these unlined ponds

may be expected to produce higher growth rates and potentially improved survival that is

more similar to growth rates observed in more natural grow-shy‐out facilities13 Historically13 the13

large13 shallow13 ponds have produced very large fish when13 utilized at low13 fish density13 The

narrow13 deep earthen13 ponds are13 used to grow13 fry13 at high density in their first13 year of life

The major downside to unlined ponds is the difficulty in harvesting fish where a lined

pond might take 8-shy‐1013 people13 a half13 day13 to13 harvest13 lined13 ponds13 require13 intensive13 weeding13

to allow seines to be pulled and therefore require many more personnel-shy‐hours13 In addition13

to harvest challenges the shallow earthen ponds tend to suffer from13 dissolved oxygen

crashes during the summer Unlined ponds also may maintain higher13 populations13 of non-shy‐

target species such as bluegill sunfish mosquito fish and bullfrog tadpoles We measured

growth rates of suckers in a large shallow earthen pond for comparison to growth in lined

ponds13

Figure13 4 Lined13 and13 earthen ponds13 of similar dimensions (approx 1000000 gallons first

and second panels) and a large13 shallow13 earthen13 pond (third panel)

38

13

Effect of sorting on growth

Razorback13 suckers13 are13 currently13 sorted13 after their first13 year of growth13 They are13

typically removed from13 one of the13 upper earthen13 ponds and13 split into13 two13 lined13 ponds for

subsequent grow-shy‐out13 The larger13 fish (gt approximately 140 mm) are placed into one pond

and the smaller individuals in another It is possible that the larger fish were more

aggressive or adept13 at taking food so this sorting process is intended to allow smaller fish

to improve their growth rate

Effect of Ich on razorback sucker growth rates

We13 evaluated13 growth13 rates13 of razorback sucker13 in the13 presence13 and absence of the

ectoparasite13 Ich (Ichthiopthirus multifiliis) Ich outbreaks can occur in wild populations13 but

hatcheries13 have13 proven excellent locations13 for Ich because13 of very high fish densities13 which13

facilitate13 the13 transfer13 of Ich13 between13 fish This common fish parasite causes direct mortality13

to razorback13 suckers as well13 as secondary bacterial13 infections13

The open spring and13 ditch13 which13 provides water to the Bubbling13 Ponds Hatchery

has long13 been infested with mosquitofish (Gambusia affinis) that harbor13 the13 Ich parasite13

and allow13 it13 to enter the hatchery with incoming13 water13 The solution13 to13 the13 Ich problem13

was to remove the mosquitofish host using13 Rotenone Razorback13 sucker growth13 rates were13

then tracked in13 the absence of this parasite for 4 months and compared with growth rates

after Ich returned to the pond and from13 previous years

Methods

Razorback growth rate in lined ponds

On May 14 2008 141 razorback suckers were tagged with 12 mm PIT tags (1342

kHz) and placed in Pond 3 (approximately 1100000 gallons13 Figure13 4)13 at Bubbling13 Ponds

Fish Hatchery Fifty-shy‐three of these tags were recovered two months later when a large

Ichthyophthirius multifilis (Ich) outbreak killed many fish in the pond On October 15 2008

an additional13 145 PIT tagged13 fish were13 also placed into Pond13 3 On13 May13 14 2009 Pond13 3

was harvested and a total13 of 141 PIT tagged fish were recovered13 Of the tagged fish13 26 fish

had13 been13 in the13 pond since May13 of 2008 (378 days13 o growth) and 115 had been13 in13 the

39

13 40

pond since October13 15 2008 (211 days13 of growth) Numbers of fish in Pond 3 after the Ich

outbreak and for the majority of the period of growth were between 3 000 and 4000 fish

A Hobotempreg temperature13 logger13 was13 also13 installed13 in Pond 3 one meter below the water

surface13 near13 the13 outflow and13 recorded water temperature every 3 hours to allow analysis

of the effects of water temperature on growth rate (Figure13 5) This Hobotemp data is

representative of other pond temperatures throughout this study

In a second experiment 210 adult13 razorback suckers13 were13 PIT tagged13 on13 May 14

2009 and13 placed13 into13 Pond13 3 upper to13 evaluate13 growth13 rates13 of larger13 razorback suckers13 at

Bubbling13 Ponds Hatchery13 under current13 rearing13 conditions13 Size of these fish at tagging13

was (mean = 285 mm range = 205 ndash 396 mm) These fish remained in the pond for 257

days and were harvested on Jan 25 2010 to provide information on growth rates of larger

razorback suckers13 under13 current rearing conditions

Figure 513 Temperatures (degC) inrearing pond at BubblingPonds Hatchery from July toSept 2009 (top graph)13 andfrom Nov to Dec 2009 (Lowergraph) Temperaturesrecorded with a Hobotempregremote data logger13 every 3hours

13

Growth rate13 in an unlined pond

To document razorback sucker growth in earthen ponds we introduced13 225 tagged13

razorback suckers13 into13 Pond13 1 lower13 (Figure 4) in February 3 2010 Additional tagged fish

from13 other studies were added to the pond throughout the growing season and the density

of 1 lower reached a maximum13 of nearly 7000 fish in early summer 2010 Density was

reduced to approximately 6000 fish by capturing fish with hoop nets on June 3 2010 54 of

these fish were tagged fish and returned to 1 lower after being weighed and measured The

pond was harvested on January13 2713 2011 and a total13 of 254 tagged fish out13 of 4296 fish

total were removed from13 the pond The pond was harvested on January 27 2011 (358 days13

of growth) and the tagged fish were weighed and measured Total number of razorbacks in

the pond at harvest13 was 4296

Effect of sorting practices on growth rates

On March 1113 200913 Pond13 5 upper was13 harvested13 and13 split into13 two13 separate13 groups

Two hundred of the smaller fish (average size = 122 mm TL) were PIT tagged and placed

into13 Pond13 7 upper and13 200 of the13 larger13 fish (average = 160 mm TL) were PIT tagged and

placed int Pond13 8 upper Density13 in Pond13 7 was13 4500 fish and13 in Pond13 8 there13 were13 6500

fish These ponds were then harvested after 1 year and growth rates were compared to

give information on the effects of current sorting practices Hobotempreg temperature

loggers were installed in13 Ponds 7 and13 8 during13 the13 grow-shy‐out period with13 water13

temperature recorded every 2 hours13 (Figure13 6)

Effect of Ich on razorback sucker growth rates

Bubbling Ponds spring was treated with Rotenone (CFT Legumine 5) at a

concentration of 2 ppm13 to remove all mosquitofish from13 the spring The treatment

consisted of two treatments 6 hours in duration on two consecutive days (April 12 -shy‐ 13)

using13 drip13 stations13 and13 backpack sprayers13 followed13 by13 an13 additional 6 hours13 of

detoxification using sodium13 permanganate Although 12 mosquitofish were captured in the

spring pond the week following the treatments subsequent minnow trapping (20 traps

checked13 daily13 for 3 weeks) did not capture any additional fish until August 11 2010 when

41

13

juvenile mosquitofish were again detected in the spring pond Minnow traps have

subsequently been set daily with several hundred individuals removed To evaluate if Ich

was also again present in the spring we captured 15 mosquitofish from13 the spring pond on

three separate days and placed them13 in an aquaria at 25 degC with 5 longfin dace known to be

free of Ich These fish were monitored for 2 weeks with no signs of Ich developing This

indicates that even though mosquitofish have returned to the spring pond the parasite is no

longer present13 although how13 long13 this condition13 will13 persist13 is unknown13

On May 1113 201013 200 juvenile razorback13 suckers were harvested out13 of Pond 5

upper (2009 year Class from13 Dexter National Fish Hatchery) and were PIT tagged and

placed into Pond 8 to evaluate if growth rates at bubbling ponds hatchery have improved

following the renovation of the spring and the removal of the Ich parasite Unfortunately13

on Sept13 8 2010 Ich was13 again13 detected13 in Pond 8 and the pond was immediately seined

and 74 tagged fish were measured to obtain growth information for the 4-shy‐month period

during13 which13 the13 pond13 was13 Ich-shy‐free13

Figure13 6 Temperatures (degC) in rearingponds 7 and 8 at Bubbling Ponds Hatchery13 from March 2009 ndash March 201013 pond 7(top13 graph)13 and13 pond 8 (Lower13 graph)13 Temperatures recorded with a Hobotempregremote data logger every 3 hours

42

13

Results

Growth in Lined Ponds

Razorback suckers13 that had been13 in13 Pond 8 upper for the13 entire13 year13 grew an13

average of 0263 mmday (789 mmmonth) and razorback suckers that had been in the

pond for 7 months (Oct -shy‐ May) grew13 on13 average of 028 mmday (843 mmmonth) (Figure13

7) These growth13 rates13 did not significantly13 differ Fish density13 in Pond 3 during13 the13

majority of the growth period was13 00032 ndash 00036 fishgallon13 Additionally no13 significant

differences in growth rate were observed between fish smaller than 210 mm TL and fish

larger than 210 mm TL when all recaptured fish were combined

We also measured the growth rate of very large fish in a lined pond On Jan13 2513 201013

156 adult fish with PIT tags were recovered from13 Pond 3 upper13 These fish were13 in the13

pond for 257 days and experienced an average13 growth13 rate13 of 024mmday or 73

mmmonth (Figure13 7)13 This growth13 rate13 is slightly13 lower13 than13 the13 average13 growth13 rate13

observed13 at Bubbling13 Ponds Hatchery in other studies (0275 mmday 825 mmmonth)

but may not be biologically meaningful We would expect larger13 fish to13 have13 reduced

growth rates according to a typical Von Bertalanfy growth model (Bertalanffy 1957) but it

appears that13 over the size range we evaluated (300 -shy‐ 450 mm TL) growth rates have not

slowed significantly compared to that of smaller13 fish grown at Bubbling Ponds13 Hatchery

Growth13 of razorback suckers13 is known13 to13 slow as13 fish reach13 larger13 sizes but it appears13 this13

reduced growth rate may not really start to be biologically meaningful at Bubbling Ponds

Hatchery13 until razorback suckers13 exceed 450 mm TL

Growth in unlined ponds

Growth13 rates13 for the13 fish recaptured13 during13 the Pond 1 lower13 thinning13 (120 days13 in

the pond) was 024 plusmn 003 mmday (729 plusmn 090 mmmonth) (Figure13 8)13 Fish13 that were13 in

the pond for nearly the entire year grew13 an13 average13 of 024 plusmn 001 mmday (726 plusmn 027

mmmonth) These growth rates are surprisingly the lowest measured growth rates for

any part of our study and differ significantly from13 every other measured growth rate

except very large13 fish (Figure13 9)13 Separating13 out13 large fish that13 were in13 the pond for the

entire year makes no difference fish that were added to the pond at TL lt300 mm grew

43

13

Gro

wth

Rat

e (m

md

ay)

020

026

032

0244 plusmn 001 mmday (733 plusmn 028 mmmonth) and and those with TL gt= 300 mm at the

start of the experiment grew 022 plusmn 003 mmday (651 plusmn 101 mmmonth)

Razorback Growth Rates in Lined Ponds

Figure 7 Growth ofrazorback suckers in(mmday plusmn standard error)in Pond 8 upper in 2008-shy‐2009 An ANOVA did notdetect any significantdifferences

7 Months Full Year 300+ mm fish

Effects of sorting on growth

One hundred and seventy five tagged razorback suckers were recovered from13 Pond

8 upper13 on March13 24 2010 (378 days13 of growth)13 These were13 the13 larger sorted13 fish (gt140

mm TL) that came out of Pond13 5 on March13 11 2009 One13 hundred and13 twenty13 two13 tagged13

razorback suckers were also recovered from13 Pond13 7 upper on March13 31 2010 (385 days13 of

growth)13 These were13 the13 smaller sorted13 fish (lt140 mm TL) that came out of Pond13 5 on

March 1113 200913 No significant differences in growth rate (mmday) were observed among

larger fish in Pond 8 and smaller fish in Pond 7 (pgt005 ANOVA) (Figure 10)13 indicating

that13 sorting may have helped to offset the original slower growth trajectory of the smaller

fish Temperatures of Ponds 7 and 8 upper remained similar throughout the year13 (Figure

5)

44

13

13

13

Gro

wth

Rat

e (m

md

ay)

Gro

wth

Rat

e (m

md

ay)

020

026

032

020

026

032

Razorback Growth in an Unlined Pond

Figure 8 Growth of razorbacksuckers (mmday plusmn standard error) in Pond 1 lower (an unlined pond)in 2010-shy‐2011 An ANOVA did notdetect any significant differences

6 Months 12 Months lt 300 mm Fish 300+ mm Fish Growth Growth

Lined vs Earthen Ponds 1 year of growth

Figure 9 Growth of razorbacksuckers (mmday plusmn standard error) in lined and unlined ponds A t-shy‐test13 did not detect a significantdifference

Lined Pond Unlined Pond 1 Yr Growth 1 Yr Growth

45

13

Effect of Sorting G

row

th R

ate

(mm

day

) G

row

th R

ate

(mm

day

)

032

020

026

032

020

026

Smaller Fish Larger Fish

Effect of Ich

Figure 10 Average growthof razorback suckers(mmday plusmn standard error)that were size-shy‐sorted intosmall fish (pond 7) and largefish (pond 8) populations At-shy‐test did not detect asignificant difference

Figure 11 Average growth ofrazorback suckers (mmday plusmnstandard error) after Ich wasremovd from the hatcheryrsquos springand after Ich was again detected inthe pond The growth rate withoutIch is significantly higher than boththe rate after Ich and the ourstudyrsquos average annual growth ratein lined ponds (ANOVA p =00003)

Growth without Ich Growth With Ich Average Annual 4 months 4 months Growth Rate

46

13

Effect of Ich on razorback sucker growth rates

Seventy-shy‐four13 tagged13 razorback suckers13 were13 recovered from13 Pond 8 on September

15 2010 These fish had13 been13 in the pond for 4 months and experienced a growth rate of

032 mmday or 97 mmmonth (Figure13 11)13 This growth13 rate13 is significantly higher (p =

005 two sample t-shy‐test) than the mean growth rate for the same group13 of tagged fish after

Ich detection (022 mmday or 65 mmmonth) and significantly higher than any other

individual growth13 rates13 observed13 to13 date13 at Bubbling13 Ponds Hatchery13 (Figure13 11)13 If this13

growth13 rate13 were13 extended throughout13 the entire13 year13 fish on average from13 Ich-shy‐free13 ponds13

would be 16 mm longer than fish from13 ponds infested with Ich Studies conducted at

Bubbling Ponds hatchery in 2008 (Ward 2008) did not reveal any effects of the treatment

chemicals on razorback sucker growth rates so it13 is likely that13 the parasite outbreaks

themselves are causing reducing growth rates rather than the chemicals used to treat the

parasites13

Conclusions

Our results suggest that under typical hatchery operations (maximizing number of

fish produced)13 the growth13 rate13 of razorback13 suckers13 is relatively13 consistent at Bubbling13

Ponds hatchery13 at 02-shy‐03 mmday (6-shy‐9 mmmonth)13 but is lower than growth13 rates13 at

other13 facilities (02 ndash 18 mmday Ward et al 2007)13 This growth13 rate13 has13 been13 constant in

both lined and unlined ponds and at all fish densities we were able to measure To achieve13

growth13 rates13 substantially higher than this will likely require13 significant changes in rearing

practices that may not be practical in order to reach numerical production13 goals

Temperature is a key variable in fish growth but seasonal growth patterns

described13 above13 (Figure13 5) demonstrate that water temperatures are high enough in

winter to maintain razorback growth Differences in water temperature by season

currently13 do not fluctuate more than 10degC at Bubbling Ponds because of the continuous

supply of water flowing through each pond (approx 225 gallonsmin) These high water

flows appear to keep pond temperatures within the thermal preference13 for razorback

suckers13 (1213 -shy‐ 28 degC Bulkley and Pimentel 1983) throughout the entire year with

temperatures rarely dropping13 below 16deg13 C (Figures 513 6)13

47

13

Fish density is another key variable in fish growth and though the number of fish in

a pond during our study ranged from13 3000 to 700013 fish we13 did not find any13 correlation13

between13 density and growth rate13 This might yield two conclusions First13 razorback

growth13 may be changed equally13 by13 densities13 at the13 hatchery13 (ie13 a density13 of 3000 fish in a

pond is as stressful13 for razorbacks as a density13 of 7000 fish) An alternative is that other

factors13 such as disease outbreaks have13 stronger13 control over fish growth13 than13 density13

Fish density13 would13 have13 to13 be13 experimentally manipulated to test13 this13 and hatchery

operations (producing the maximum13 number of fish) prevented our manipulating density13

in ponds for this13 work The trouble with manipulating density demonstrates the difficulties

associated with changing13 hatchery13 practices experimenting with density would have

prevented BPH from13 meeting13 production13 goals Given that the stocking of smaller

razorbacks has met with very little success perhaps BPH goals could be changed from13

producing 12000 fish at 300+ mm per year to a smaller number of very large fish each

year Growing13 fewer13 larger13 fish could potentially be accomplished in the same time frame

as more smaller fish but a better understanding of how density alters growth rate would

be required to be confident13 of this

The very slow growth13 in the13 earthen13 unlined13 Pond 1 lower13 was very surprising We13

had13 anticipated13 that the13 diversified diet13 cover and13 other13 habitat features13 provided by13

unlined ponds would yield dramatically increased growth rates However these traits were

not enough to offset high fish densities and in fact the unlined pond in our study13 suffered

mortality to bring densities down to that observed normally in lined ponds

Our data13 suggest13 that razorbacks13 sucker13 growth13 rates13 are13 higher in lined13 ponds13

However we13 think the reasons13 for the13 very slow growth we observed13 in the13 unlined13 pond13

in our study13 is instead13 linked13 to13 the13 usage13 of Pond 1 lower13 during13 the13 study13 rather13 than13

intrinsic13 slow growth13 in earthen13 ponds First the pond was at extremely high density for at

least part of the study The volume of Pond 1 lower has not been estimated but hatchery

managers suggest 1500-shy‐2000 fish is an appropriate number of individuals so this pond

was at a very high density for much of the experiment Second dissolved oxygen is often

very low in the13 large13 earthen13 ponds during the heat of summer much lower than that of

lined ponds This will both limit the number of fish that can survive in the pond and almost

certainly13 increases stress13 of these13 fish potentially13 reducing growth13 The DO crashes also13

48

13

limit the amount of feed hatchery managers can give fish in these ponds sometimes for

days or weeks at a time which further reduces growth during warm13 weather

Our data13 suggests that13 growth rates at the Bubbling13 Ponds Fish Hatchery are likely

as high as possible given13 the pond densities required to meet production goals and the Ich-shy‐

infested water that feeds the facility Sorting practices are successful in helping as many

fish as possible reach stocking length as fast as possible Unlined ponds may be able to

grow13 large13 fish at low13 densities13 but whatever factors allow13 for that13 growth are not13 able to

overcome high fish density The removal of invasive13 fis that act as13 a host for the13 parasite13

Ich fish from13 the Bubbling13 Ponds spring13 allowed the highest13 growth rate at 032 mmday13

(96 mmmonth) but that growth rate decreased again as Ich re-shy‐infested13 the13 hatchery13

Consistently13 achieving13 growth13 rates13 as high or substantially13 higher than13 this13 will likely13

require13 significant changes in rearing practices that may not be practical in order to13 reach13

numerical production13 goals

Two major changes that might result in higher growth rates are substantially

reducing fish density and modifying the way spring water is delivered to the facility (via

either repeated chemical treatments or enclosed concrete water diversions) to eliminate

Ich from13 the hatchery source water Other potential changes not address by our work

include13 flow-shy‐training razorbacks much previous literature including MSCP-shy‐funded13 work

on razorback suckers13 suggests13 that fish growing13 in flowing water will grow13 faster than fish

in still water (Jorgensen and Jobling 1994) Furthermore there are a wide variety of

potential benefits associated with growing13 fish13 in flowing13 water in addition13 to increased

growth13 rates13 (Davidson13 199713 Castro13 et al13 2011) Another option13 for increasing13 growth13

rates13 include13 changing to13 intensive13 culture13 in large circular13 tanks

Finally given that the stocking of smaller razorbacks has met with very little

success13 perhaps13 BPH13 goals13 could13 be13 changed from13 producing 12000 fish at 300+ mm per

year to a smaller number of very large fish each year Growing fewer larger fish could

potentially be accomplished in the same time frame as more smaller fish but a better

understanding13 of how density13 alters growth13 rate13 would13 be13 required to13 be13 confident of this

49

13

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower13 Colorado13 River Multi-shy‐Species13

Conservation Program13 (LCRMSCP) under Work Task C10 We13 thank Ty Wolters13 Tom13

Burke13 and Eric13 Volkman for their support of this research and Frank Agygos and Dave

Billingsly13 of the Bubbling13 Ponds Fish Hatchery13 for their willingness to participate in13 this

research13 and13 for their technical assistance We also thank the LCRMSCP fish group from13

Boulder City13 NV for their assistance with harvesting13 ponds and tagging13 fish13

50

13

Literature13 CitedAnders P J 1998 Conservation aquaculture and endangered species can objective science13

prevail13 over risk13 anxiety Fisheries 23(11) 28-shy‐31

Anderson R O and R M Nuemann 1996 Length weight and associated structural indicesPages 447 ndash 482 in B R Murphy13 and D13 W Willis13 editors13 Fisheries techniques13 2ndedtion American Fisheries13 Society13 Bethesda13 Maryland

Bain M B J T Finn and H E Brooks 1988 Streamflow regulation and fish communitystructure13 Ecology13 69382-shy‐392

Bays J H Zarbock R Whitman and T Murphy 2005 Conceptual design and managementof native13 fish refugia on the13 lower13 Colorado13 River In13 CL Spring13 and13 S Leoneditors Proceedings of two symposia Restoring native fish to the lower ColoradoRiver13 interactions13 of native and non-shy‐native13 fishes 13ndash1413 July13 1999 Las13 Vegas13 Nevada13 Restoring13 natural function within a modified riverine environment thelower Colorado River13 8ndash913 July13 1998 U S Fish and13 Wildlife13 Service Southwestern13 Region Albuquerque New Mexico Pages 167-shy‐177

Bertalanffy L Von 1957 Quantitative laws in metabolism13 and growth13 Q Rev Biology 32217 ndash 231

Bingham T B Scheer and C McAda 2003 Propagation facilities in Grand Valley (24 RoadHatchery Horsethief13 Ponds and13 grow-shy‐out ponds) for captive13 rearing13 ofendangered13 fishes for the13 upper13 Colorado13 River basin13 Colorado River RecoveryProgram FY2003 annual project report13 US Fish and13 Wildlife13 Service GrandJunction13 4pp

Birchell G J and K Christopherson 2004 Survival growth and recruitment of larval andjuvenile razorback13 sucker (Xyrauchen texanus) introduced13 into13 floodplain13 depressions13 of the13 Green River Utah13 Final report13 Upper13 Colorado13 RiverEndangered Fish Recovery Program13 Project No C-shy‐6RZ Publication Number 04-shy‐1513 Utah13 Division of Wildlife13 Resources Salt Lake13 City13 Utah13 67 pages

Brannon E L 1993 The perpetual oversight of hatchery programs Fishery Research 1819-shy‐27

Brett J R 1979 Environmental Factors and growth pages 599-shy‐67513 InW S Hoar13 D13 J13 Randall and J R Brett (eds) Fish Physiology Volume 8 Bioenergetics and GrowthAcademic Press New York

Brooks J E 1986 Annual reintroduction and monitoring report for razorback suckerXyrauchen texanus in the Gila River Basin Arizona 1985 US Fish and WildlifeService13 Offices of Endangered13 Species and Fishery13 Resources Albuquerque 23 pp

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Brunson13 R E and K D13 Christopherson13 200513 Larval13 razorback13 sucker and bonytailsurvival and13 growth13 in the13 presence13 of nonnative13 fish in the13 Baeser13 floodplainwetland of the middle Green River Final report prepared for Upper13 Colorado RiverBasin Endangered Fish Recovery Program Project No C-shy‐6-shy‐rz-shy‐bt Publication13 No 05-shy‐26 Utah13 Division of Wildlife13 Resources13 Vernal13 32 pp

Bulkley R V and R Pimentel 1983 Temperature preference and avoidance by adultrazorback suckers Transactions of the American Fisheries Society 112601-shy‐607

Burke13 T13 199513 Rearing13 wild razorback13 sucker larvae in13 lake-shy‐side13 backwaters13 LakeMohave ArizonaNevada Proceedings of the Desert Fishes Council 2635

Busacker G P I R Adelman and E M Goolish13 199013 Growth13 Pages 363 ndash 387 in C BSchreck and p B Moyle editors Methods for fish biology American FisheriesSociety Bethesda Maryland

Castro V B Grisdale-shy‐Helland S J Helland T Kristensen S M Jorgensen J Helgrud13 GClaireaux A P Farrell A Krasnov and H Takle 2011 Aerobic training stimulatesgrowth and promotes disease resistance in Atlantic salmon (Salmo salar)Comparative Biochemistry and Physiology -shy‐ Part A Molecular amp IntegrativePhysiology13 160(2) 278-shy‐290

Czapla T E 2002 Facilities plan for the production of endangered fishes to meet statestocking13 plans13 as13 part of the13 Upper13 Colorado13 River Endangered13 Fish RecoveryProgram Upper Colorado River Basin Recovery Implementation Program US Fishand Wildlife Service13 Denver13 9 pp

Davidson W 1997 The effects13 of exercise13 training on teleost fish a review of recentliterature Comput Biochem Physiol 117A67ndash75

Figiel Jr C R 2005 Annual report fiscal year 2004 Willow Beach National13 Fish HatcheryUS Fish and Wildlife13 Service Willow Beach 17 pp

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52

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Jorgensen E H and13 M Jobling 1994 Feeding and13 growth13 of exercised13 and13 unexercised13 juvenile Atlantic salmon in freshwater and performance after transfer to seawaterAquaculture International 2 154-shy‐164

Kaeding L R and D B Osmundson 198913 Colorado13 Squawfish13 and13 razorback sucker grow-shy‐out pond studies as part of conservation measures for the green mountain andRuedi reservoir water sales Final report for agreement number 6-shy‐AA-shy‐60-shy‐00150

Koebele13 B P13 198513 Growth and the size hierarchy effect an experimental assessment ofthree proposed mechanisms activity differences disproportional food acquisition13 pysiological stress Environmental Biology of Fishes 12 181-shy‐188

Kretschmann A E and L L Leslie 2006 Razorback sucker (Xyrauchen texanus) status13 reproduction and recruitment in Senator Wash Reservoir CA Final Report13 to USBurea of Reclamation Cooperative Agreement No 00-shy‐FG-shy‐34-shy‐ 0009 p 32 ArizonaGame and Fish Department Phoenix

Marsh13 P13 C13 1987a13 Digestive tract13 contents13 of adult razorback suckers13 in Lake13 MohaveArizona-shy‐Nevada Transactions of the American Fisheries Society 116117-shy‐119

Marsh P C 1987b Native fishes at Buenos Aires National Wildlife Refuge and ArizonaState University Research Park Arizona opportunities for management researchand public13 education13 on13 endangered species13 Proceedings of the Desert13 FishesCouncil 1967-shy‐78

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Marsh13 P13 C13 200013 Fish population13 status and evaluation13 in13 the Cibola13 High Levee PondFinal report agreement number 99-shy‐FG-shy‐30-shy‐00051 US Bureau of ReclamationBoulder City13 Nevada13 20 pages

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Marsh P C B R Kesner and C A Pacey 2005 Repatriation as s management strategy13 to13 conserve a critically13 imperiled fish species North American Journal of FisheriesManagement 25 547-shy‐556

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Marsh13 P13 C13 and J13 E Brooks13 198913 Predation13 by ictalurid catfishes as a deterrent13 toreestablishment of hatchery-shy‐reared13 razorback sucker The Southwestern Naturalist34188-shy‐195

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Minckley13 C13 O and M LaBarbara13 199913 Report13 on13 native fish grow-shy‐out facilities13 at Cibolaand Imperial National Wildlife Refuges 1993-shy‐199513 US Fish and13 Wildlife Service13 Parker Fishery Resources Office Parker Arizona

Modde13 T13 199613 Juvenile razorback sucker (Xyrauchen texanus) in a managed wetlandadjacent13 to the Green13 River13 Great13 Basin13 Naturalist13 56375-shy‐376

Modde T KP Burnham and E J Wick 1996 Population status of the razorback sucker13 inthe middle Green River (USA) Conservation13 biology 10 110-shy‐119

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Modde T Z H Bowen and D C Kitcheyan 2005 Spatial and temporal use of a spawning13 site in the middle Green River by wild hatchery-shy‐reared13 razorback suckers13 Transactions of the American Fisheries Society 134937-shy‐944

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Mueller G 1995 A program13 for maintaining the razorback sucker in Lake MohaveAmerican Fisheries Society Symposium 15127-shy‐135

Mueller13 G13 200613 Ecology of the bonytail13 and razorback13 sucker and the role of offchannelhabitats13 in their13 recovery Scientific13 investigations13 report 2006-shy‐5065 US GeologicalSurvey13 Denver

Mueller G and E Wick 1998 Testing of golf course ponds at Page Arizona for suitability13 as grow-shy‐out facility for razorback sucker using surplus fish from13 Ouray NationalFish Hatchery National Park Service US Fish and13 Wildlife13 Service and UtahDivision of Wildlife13 Resources 28 pages

Mueller13 G13 and T13 Burke13 200513 Survival13 of young13 razorback13 sucker (Xyrauchen texanus) inrelation to13 stocking rates13 (fishha)13 and13 in the presence13 or absence13 of predatorcommunities in Lake Mohave Arizona-shy‐Nevada13 Pages13 155-shy‐16313 in Proceedings of two13 symposia restoring native fish to the lower Colorado River interaction13 of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 Nevada US Fish and Wildlife13 Service Southwest Region Albuquerque New Mexico

Mueller13 G13 J13 Carpenter13 and P13 C13 Marsh13 200413 Cibola13 High Levee Pond annual report 2004US Geological Survey Fort Collins13 Science Center13 Colorado13 and Arizona StateUniversity Tempe 23 pages

Nesler T P K Christopherson J M Hudson C W McAda F Pfeifer and T E Czapla 2003An integrated stocking plan for razorback sucker bonytail and Colorado13 pikeminnow for the Upper Colorado River Endangered Fish Recovery ProgramAddendum13 to State Stocking Plans Upper Colorado River Basin Recovery13 Implementation Program 12 pp

Papoulias13 D and W13 L Minckley13 1992 Effects13 of foo availability13 on survival and growth13 of larval razorback suckers13 in ponds Transactions of the American Fisheries Society121340-shy‐355

Paukert13 C P D L Ward13 P J Sponholtz13 and K13 D Hilwig13 Effects13 of repeated hoopnetting13 on bonytail chub13 Journal of Freshwater13 Ecology13 20(4) 649-shy‐653

Pfeifer F M13 C Baker13 and M13 Montagne13 199913 Propagation13 facilities13 in the13 Grand Valley13 (24 Road13 Hatchery13 Horsethief13 Ponds and13 grow-shy‐out ponds) for captive rearing of

55

13

endangered13 fishes for the13 Upper Colorado13 River Basin13 Colorado13 River Recovery13 Program FY 99 annual project report Project No 29a13 US Fish and Wildlife Service13 Grand13 Junction13 5pp

Pfeifer F S Seversen and M Montagne 2003 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2003 annual reportProject No 29b13 US Fish and Wildlife13 Service Vernal13 4pp

Rabago-shy‐Castro J L Sanchez13 J G Perez-shy‐Castaneda R and13 Gonzalez-shy‐Gonzlez A 2006Effects of the prophylactic use of Romet-shy‐3013 and13 copper13 sulfate13 on growth13 condition13 and feeding13 indicies in13 channel13 catfish (Ictalurus punctatus) Aquaculture 253 343-shy‐349

Reinitz GL L E Orme and F N Hitzel 1979 Variations of body compositio and growth13 among strains of rainbow trout Transactions of the American Fisheries Society 108204-shy‐207

Ruppert13 J13 B P B Holden13 and P D Abate 1999 Age estimation and growth of razorbacksucker13 Xyrauchen texanus in Lake13 Mead Nevada Proceedings13 of the Desert FishesCouncil 3040

Schnoor K D and J Logan 2002 Operation and maintenance of JW Mumma nativeaquatic13 species restoration facility Colorado Colorado River Recovery Program FY2002 annual project report13 Project No 29d Colorado13 Division of Wildlife Alamosa3pp

Salisbury13 L13 1998 Factors13 affecting razorback13 sucker growth13 in Lake13 Mohave backwaters13 MS Thesis13 Unviersity13 of Nevada13 Las13 Vegas

Schooley J13 D13 and P C13 Marsh13 2007 Stocking of endangerdd13 razorback13 suckers13 in thelower Colorado River Basin13 over three decades 1974-shy‐2004 North American Journalof Fisheries Management 27 43-shy‐51

Severson S H H M Tyus and G B Haines 1992 An evaluation of feeds for raisingrazorback sucker Xyrauchen texanus Journal of Applied Aquaculture 155-shy‐65

Toney D P 1974 Observations13 on the13 propagation13 and13 rearing13 of two13 endangered species13 in a hatchery environment Proceedings of the Annual Conference of the Western13 Association of State Game and Fish Commissions 54 252-shy‐259

Tyus H M13 1998 Razorback sucker13 (Xyrauchen texanus) recovery plan13 University13 ofColorado Center for Limnology Boulder13 76 pages

Tyus H M13 and13 S H Severson 1990 Growth13 and13 survival of larval razorback suckers fedfive formulated diets The Progressive Fish Culturist 52197-shy‐200

56

13

Ulibarri M E 2003 Annual report fiscal year 2001 Dexter National Fish Hatchery13 andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 26 pages

Ulibarri M E 2003 Annual report fiscal year 2002 Dexter National Fish Hatchery andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 59 pages

USBR 2006 Lower13 Colorado13 River Multi-shy‐Species Conservation Program final fishaugmentation plan Boulder City 19 pp

USFWS 2002 Razorback sucker (Xyraouchen texanus) recovery goals Amendment andsupplement to the Razorback Sucker Recovery Plan13 US Fish and Wildlife Service13 Region 6 Denver13 Colorado

USFWS 1999 Annual report 1999 Ouray National Fish Hatchery Vernal 25pp

USFWS 2004 Management plan for the big-shy‐river13 fishes of the13 lower13 Colorado13 river basinamendment and supplement to the bonytail humpback chub Coloradopikeminnow and razorback sucker recovery plans

USFWS13 2005 Station13 profile13 of the13 Dexter13 National Fish Hatchery13 and Technology CenterUS Fish and Wildlife13 Service Dexter

Valdez R A P G Mangan R Smith and B Nilson 1982 Upper Colorado River fisheriesinvestigations13 inW H Miller J J Valentine D L Archer H M Tyus R A Valdezand L13 Kaeding13 editors13 Colorado River Fishery13 Project13 Part 2 Field13 investigations13 US Bureau of Reclamation Salt Lake City Utah

WBNFH 2004 Culture methods of the endangered razorback sucker Xyrauchen texanusUS Fish and Wildlife13 Service Willow Beach National Fish Hatchery13 8 pp

Ward D 2008 Effects of disease treatments on growth of razorback sucker ReportSubmitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 Inpartial fulfillment of work task C10 agreement number 06FG30039

Ward13 D13 M Childs and W Persons 2007 Factors13 affecting13 growth13 of razorback sucker13 (Xyrauchen texanus) in captivity Literature review and knowledge assessmentReport Submitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 In partial fulfillment of work task C10 agreement number 06FG30039

57

Appendices

Appendix 1 Survey Questions Survey of Razorback Sucker Culture in the

Southwestern United States

The enclosed survey is being distributed by the Arizona Game and Fish Department to razorback sucker culture facilities throughout

the Southwestern United States The purpose of this survey is to consolidate information regarding culture of this species so that

appropriate facility improvements can be considered for Bubbling Ponds Hatchery in Arizona Specifically we wish to increase

growth rate and production efficiency at the hatchery Information gathered in this survey will be summarized in a final report to US

Bureau of Reclamation in Boulder City NV and disseminated to all facilities that participate in the survey A workshop to discuss

the findings of this study as well as to share general information concerning razorback sucker culture will be organized by the

Arizona Game and Fish Department at the conclusion of this study and all participants will be invited

Thank you for taking the time to fill out this survey Please contact Mike Childs if you have questions or would like to discuss the

survey

Mike Childs

mchildssedonanet

(928) 639-1346

(928) 634-1279

Facility_____________________________________ Date___________________

Contact Phone _____________________________

ContactPerson_______________________________

Contact Email _______________________________

1 Water quality ranges at this culture facility

Season

Spring (Mar-May) Summer (Jun-Aug) Fall (Sept-Nov) Winter (Dec-Feb)

Temperature (C)

PH

DO (mgL)

PO4 (mgL)

TDS (mgL)

Hardness (mgL)

CaCO3

Pathogens

37

13

include13 flow-shy‐training razorbacks much previous literature including MSCP-shy‐funded13 work

on razorback suckers13 suggests13 that fish growing13 in flowing13 water13 will grow faster13 than13 fish

in still water (Jorgensen and Jobling 1994) Furthermore there are a wide variety13 of

potential benefits associated with growing13 fish13 in flowing13 water in addition13 to increased

growth13 rates13 (Davidson13 1997 Castro13 et al 2011)13 Finally given that stocking of smaller

razorbacks13 has13 been13 largely unsuccessful13 perhaps13 BPH goals could be changed from13

producing 12000 fish at 300+ mm per year to a smaller number of very large fish each

year Growing fewer larger fish could potentially be accomplished in the same time frame

as more smaller fish but a better understanding13 of how13 density alters growth rate would

be required to be confident13 of this

7

13

I Literature13 Review

Section13 SummaryThe few remaining razorback sucker populations are sustained by captive rearing and stockingprograms Captive-shy‐reared razorback suckers commonly13 experience13 high predation whenstocked into natural environments This13 creates13 the need to rear fish to larger sizes13 in captivityand to13 find new ways to13 improve growth for captive-shy‐reared fish We reviewed publishedliterature and agency reports for information on factors that affect growth of13 razorback suckerSite visits to13 razorback sucker production facilities and surveys of fish hatchery13 personnel wereconducted to obtain information on current rearing practices Razorback sucker growth is13 extremely13 variable13 and impacted by13 many13 factors including13 fish size13 and age sex densityamount of living13 space quality13 and quantity13 of food genetics and temperature This makesevaluations of individual factors that affect growth difficult Culture13 practices for razorbacksuckers13 vary widely and include differences13 in rearing environments rearing densities feedingregimes and types of feed as well as grading or13 sorting practices The focus at most razorbackrearing facilities is production so the types of data that are collected13 are often insufficient fordetailed13 evaluations of rearing practices on growth Calculated13 growth13 rates from theliterature vary widely and range from 02 ndash 1813 mmday Typically the highest growth13 rates arereported from natural or semi-shy‐natural pond environments These growth rates indicate thatjuvenile razorback suckers have a very high growth potential under ideal rearing conditionsDetailed replicated studies are needed to accurately compare the effects of individual rearingpractices on13 growth These types of studies will ultimately provide both time and cost-shy‐savings13 to production facilities by reducing the time it13 takes for razorback suckers to reach stockingsize improving overall production efficiency

8

13

Introduction

State and federal wildlife management agencies have been rearing razorback

suckers in captivity since the 1970rsquos (Toney 1974 Hamman 1985) to augment declining

natural13 populations Both wild-shy‐caught larvae13 and captive-shy‐bred fish are reared at fish

hatcheries13 and13 grow-shy‐out ponds throughout the13 southwestern13 United13 States13 (reviewed13 in

Mueller 2006) Each facility has unique environmental conditions and different rearing

methods which yield different growth rates Unlike commercial fish species which have

been cultured and studied extensively little published information is available on the

effects of various rearing methods on growth of razorback sucker

Low survival rates13 of stocked13 razorback suckers13 (Brooks13 1986 Marsh13 and13 Brooks13

1989 Marsh13 and13 Pacey13 2005)13 have13 caused13 target sizes for stocking13 to13 steadily13 increase13 in

efforts to reduce predation mortality (Marsh et al 2005 Schooley and Marsh 2007)

Rearing fish to larger sizes comes with increased costs and creates the need to know which

factors13 have the greatest impact on growth rate and how these factors can be controlled to

maximize growth This document compiles and summarizes information on current

captive13 rearing practices13 and associated13 growth13 rates13 for razorback sucker13

We reviewed relevant13 published literature and agency reports on13 razorback13 sucker

to compile background information regarding the effects of environmental factors and

rearing methods on growth A questionnaire was developed (Appendix 1) and sent to

hatchery managers who rear razorback suckers Follow up surveys13 were13 also13 conducted13

by telephone (Appendix 2) Information on rearing densities water quality diseases and

management practices at each facility were recorded Site visits to Bubbling Ponds State

Fish Hatchery13 in Arizona Dexter National Fish Hatchery in New Mexico Grand Valley

Endangered Fish13 Facility13 in Colorado13 Ouray13 National13 Fish13 Hatchery13 in Utah and the Willow

Beach National Fish Hatchery in Arizona were also conducted as part of this knowledge

assessment Telephone interviews were conducted with personnel from13 other locations

that13 produce razorback13 suckers (Uvalde National13 Fish Hatchery13 Hualapai Ponds13 Lake

Mead Fish Hatchery and JW Mumma Fish Hatchery) or facilities that formerly produced

razorback suckers but currently focus on other species (Wahweap Fish Hatchery Achii

Hanyo13 National Fish Hatchery Mora National Fish Hatchery)

9

13

Information from13 all of these sources is summarized to aid future researchers in the

design of more detailed studies on razorback sucker13 growth Understanding the13 factors13

that13 control13 razorback13 sucker growth will13 allow13 expanded fish-shy‐rearing capabilities13 and13 aid13

in reaching management objectives for stocked fish Preservation of genetic resources for

razorback suckers13 depends on captive rearing and stocking programs until permanent

solutions to factors that prevent wild recruitment can be found

Summary13 of Facilities

There are13 over 50 locations13 that have13 been13 used to13 rear13 razorback suckers13 (Table13 1) These

include13 both13 intensive13 culture13 facilities13 with13 raceways13 or circular13 tanks13 as13 well as13

production13 ponds13 golf-shy‐course13 ponds and natural floodplain-shy‐wetlands The majority of

razorback suckers that are stocked come from13 six major production facilities Bubbling

Ponds State13 Fish13 Hatchery13 The Grand13 Valley13 Endangered13 Fish Facility13 and13 Dexter13 Ouray13

Willow13 Beach13 and Uvalde National13 Fish Hatcheries13 Tables 2-shy‐313 outline13 the13 types13 of fish

holding facilities and water quality conditions that exist at each of these main production

locations A brief summary of procedures for rearing razorback suckers at each of these

facilities13 follows

These summaries are based on interviews conducted with hatchery personnel in July 2007 during site visits

This information13 is provided only to give a brief overview of razorback grow-shy‐out procedures Please verify13

accuracy13 of specific information with individual hatchery managers

10

13

Table13 1 List of locations13 that have13 been13 used to13 grow-shy‐out razorback suckers

$$amp ()amp$+ ($ampamp$+( $amp()$+ $amp()amp+(-0(12(342056( )0(-75amp8(95amp( 0$$05(lt==gt( 5amp+(amp4amp(Aamp+amp050+(12(14$6( 5amp+(amp4amp8(B$5+( B7$(lt==lt8()C0C05(lt===8(D0$05(0($(lt==E8(amp2F(0($(lt==E(

GltHI5+(342056J( K0L05(Damp$(12(342056( K0L058(D0M(0L4( N$055(lt==E( FF(-0(12(342056( D05(9$F8(B$5+( -42amp5(amp+($amp(lt==lt( OP0(0+(342056( $+05(B68(D0Q+( N-R(lt==gt( S56(Damp$(12(342056( D05(T05amp$8(N2( B7$(lt==lt8(U5Qamp(0($(lt==H8()C0C05(0($(lt==E8(0$$05(lt==gt8(N-1V-(WXXX( NQ$+0(Damp$(12(342056( NQ$+08(Y0L( N-R(lt==gt( V2M07(12(342056( M058(N2( B7$(lt==lt8(Qamp(amp+(5+M42(lt===( V$$M(042(Damp$(12(342056( 0$M(3Q05(KF(amp(B$5+(RQ058(95amp( 3ampamp(WXXgt( 942(3amp6( D05()5P058(95amp( N-1V-(lt==Z( --+-0+-12-3(4-5 )005(7amp+( 5amp+(amp4amp8(B$5+( Y2+(amp2F8(705amp$(4FFamp4amp( ltgt(5+(7amp+( 5amp+(amp4amp8(B$5+( )C0C05(0($[(WXXX( amp+(7amp+(( 5amp+(amp4amp8(B$5+( )C0C05(0($[(WXXX( B$6F05()amp+( BampC$0amp40(C(B$5+(amp+(ampampamp( )C0C05(0($[(WXXX8(B7$(lt==lt( B$5+(I(W](++amp$($00+(7amp+( 5amp+(T$$068(B$5+( )C0C05(lt===( KP0(5+(7amp+( 5amp+(T$$068(B$5+( )C0C05(0($[(WXXX( 32$amp0(7amp+( 5amp+(T$$068(B$5+( )C0C05(0($[(WXXX( 35020C(505amp(7amp+( 5amp+(amp4amp8(B$5+( )C0C05(lt===8(B7$(lt==lt( 0-6-3+ $620(Famp47$($C(450( $6208(B$C5amp( ^50amp($C(450_(9-N(R00542()5P( 08(95amp( 52(WXXH8(52(WX]( )0($C(450(7amp+( )08(95amp( 0$$05(amp+(V4P(WXX]( 768639 0amp(50(DVR( -2(C(Y4amp8(95amp( 52(WX]( B$(32(O0Q00()amp+( B$(Damp$(V$+$C0(R0C08(D05($6208(B$C5amp( 52(lt===8(amp4P$06(amp+(O55(WXXX8(0$$05(lt==gt( SQ05amp(M$+$C0(amp0F0amp(50( D05(OP0(0+(ampC$M8(D0Q+( N-R(lt==gt( -0amp5(V2( D52(C(`F8(95amp( ^5042Fampamp(amp+(O0$0(lt==gt8(amp4P$06(amp+(O55(WXXX( )1(+ KQ(4Q0( OP0(2Q08(95amp( 0$$05(WXXlt8(0$$05(amp+(5P0(lt==Z( 95amp(aQ0amp$0( OP0(2Q08(95amp( -$56(WXX]( -2(-+0Mamp+05( OP0(2Q08(95amp( -$56(WXX]( `F(BQ0( OP0(2Q08(95amp( 0$$05(WXXlt8(0$$05(amp+(5P0(lt==Z( Kamp+6( OP0(2Q08(D0Q+( -$56(WXX]( D52(B20F020Q0( OP0(2Q08(D0Q+( -$56(WXX]( D52(X($0( OP0(2Q08(D0Q+( Y6(V$05(N-R8(705amp$(4FFamp4amp( V$$M( OP0(2Q08(D0Q+( Y6(V$05(N-R8(705amp$(4FFamp4amp( D0Q+(A( OP0(2Q08(D0Q+( Y6(V$05(N-R8(705amp$(4FFamp4amp( D0Q+(O5Q0( OP0(2Q08(D0Q+( Y6(V$05(N-R8(705amp$(4FFamp4amp( 0+58lt+--457(5 9Q0(50ampampamp( D05(T05amp$8(N2( )C0C05(0($[(lt==E( ampamp(5+0( D05(T05amp$8(N2( )C0C05(0($[(lt==E( 2ampamp(F( D05(T05amp$8(N2( ++0(amp+(3amp0(lt==Z( O0(W=( D05(T05amp$8(N2( N-1V-(WXXX( O0(F( D05(T05amp$8(N2( ++0(amp+(3amp0(lt==Z( S$+(425$06(V2( D05(T05amp$8(N2( ++0(amp+(3amp0(lt==Z8(++0(WXXgt( O00+(7amp+(amp(20(Namp2(amp( D05(T05amp$8(N2( U5Qamp(0($(lt==H8()C0C05(0($(lt==E( =($+ 1$6+(OF(0(75P(GY0$0(75ampJ( O(T08(D0Q+ (52(WXXH( Y5amp++(-0(amp5(B$$00( 9$F8(B$5+( -42amp5(amp+(Oamp(lt==lt( 5MI(7amp+( D05(15Fampamp8(D( -42amp5(amp+(Oamp(lt==lt(

11

13

Table 2 Facilities available at major razorback sucker fish hatcheries

$amp( )$+(-+( 0(1(2$amp3amp(( 4-56+ amp7(8-+1$(9+( lt3-5( 8=$33( 23gt(805(

$amp()amp+(-(012345( 0(0+amp(A(BBCC(05 ampD(ED F CGBH IACCCACCC BJH K$+L(0D

amp$+(M$gt$ O-$+(+($P

B N B

CGBH IACCCACCC BABHC FANCC

BJH

Qamp+-3$+($P F FHC 637134(801amp0$(-(012345( H(L$33gt($O-amp1+(gt33A(

BCCC(05 ampDRK$+L(0D amp$+(M$gt$ M$-3$+($P Qamp+-3$+($P Qamp+-3$+($P

9O-$+amp$

SF S BC SC HC TC

CGI((IGC( HAHCC HSC IBC BCC IC

9O-$+amp$ BC SC 940amp+(amp21amp(8013(-(-02$15( U-ampamp0$3(D+ampPamp(gt$+ Qamp+-3$+($P IS VCC IB

W+Lamp1(+$+amp(0D( E-50D(+ampX+(gt$+( Qamp+-3$+($P JT BCC H K$+L(ED T CGBH(Y(CGH(

lt405(801amp0$(-(012345( J(L$33gt(gt33A(FCC(05( ampD(0D BS CGIBH(Z(CGBH( IC Qamp+-3$+($P NC IBC H Qamp+-3$+($P BJ VCC IC((IH

=$$gt(302(801amp0$(-(012345( 3$+(L$D(Q3+$D( MampX+(gt$+( amp$+(M$gt$ N IAHCC

amp$+(M$gt$ IF IFACCC 9O-$+amp$ FC IC

0$+3(801amp0$(-(012345( B([0(9O-amp1+()33A( IHCC(05 ampD(0D II I

K$+L(0D amp$+(M$gt$ amp$+(M$gt$

NJ B IB

GBH(Y(IGC( FAHCC IACCC

Qamp+-3$+($P Qamp+-3$+($P

IB N

BCC NACCC

12

13

Table13 3 Water13 quality13 ranges13 at each13 culture facility$amp ($)$++) -+$

-)amp012$)32$45 -6+)01763865 9$01-+3lt5 =amp+)01gt+39+5 $amp()amp+ ++)$6)+01A5

J gtLNL01O5 8P$ampamp401O5 ($Q+

BC3DE DD3DF BG3DB KLM3MLE KLH3MLI KLH3MLF CLM3BFLE CLM3BFLE CLM3BFLE

RQS0Aamp$ RQS0Aamp$ RQS0Aamp$ )ampQTamp$ )ampQTamp$ )ampQTamp$

8+)$O(6+T$ 8+)$ 8+)$ A6$)amp A6$)amp A6$)amp

BH3BI KLH3MLE CLM3BFLE

RQS0Aamp$ )ampQTamp$ 8+)$ A6$)amp

-01 ++)$6)+01A5 J gtLNL01O5 8P$ampamp401O5 ($Q+

BK3DE DD3DM BK3DE KLC3MLC KLC MLC DLM3GLK DLM3GLK DLM3GLK BIC3BMM BIC3BMM BIC3BMM

2ampamp$03040UQ$0amp0)6Q0amp0UampQ0ampamp0VampQ

BE3BI KLC

DLM3GLK BIC3BMM

213amp+(4amp50amp ++)$6)+01A5 J gtLNL01O5 8P$ampamp401O5 ($Q+

DH3DC DH3DC DH3DC KLK3MLE KLK3MLE KLK3MLE KLE3KLC ILC3KLE ILE3ILC BEE BEE BEE

+0$0amp+amplt+066)+0V$ampamp4S0RQ0$0)TP0T

DH3DC KLK3MLE FLC3ILC BEE

6137 ++)$6)+01A5 J gtLNL01O5 8P$ampamp401O5 ($Q+

BB3DC BB3DC BB3DC KLF3MLD KLF3MLD KLF3MLD CLE3BD CLE3KLD CLE3KLD BBG BBG BBG Aamp$ Aamp$ Aamp$

BB3DC KLF3MLD CLE3KLD BBG Aamp$

8$$9(35 ++)$6)+01A5 J gtLNL01O5 8P$ampamp401O5 ($Q+

BK3DE DE3DC BK3DE KLC3MLE KLC3MLE KLC3MLE HLE3GLE HLE3ILE HLE3GLE HEE3FEE HEE3FEE HEE3FEE RQS0Aamp$ RQS0Aamp$ RQS0Aamp$ A6$)amp A6$)amp A6$)amp 8+)$ 8+)$ 8+)$

BH3BM KLC3MLE FLE3GLE HEE3FEE RQS0Aamp$ A6$)amp 8+)$

lt3$+ ++)$6)+01A5 J gtLNL01O5 8P$ampamp401O5 ($Q+

BG3DI DI3DM BM3DM KLK3MLD KLK3MLD KLK3MLD FLE3BDLE FLE3BDLE FLE3BDLE DDI DDI DDI

A6$)amp

BF3BM KLK3MLD FLE3BDLE DDI

Bubbling Ponds State13 fish Hatchery13

Bubbling Ponds Fish Hatchery in Arizona does not maintain razorback sucker

broodstock on site Razorback suckers are received either as juveniles from13 Willow Beach

National Fish Hatchery13 or as13 newly-shy‐hatched larvae from13 Dexter13 National Fish Hatchery

Larval fish are13 typically13 placed13 into13 an unfertilized unlined 0613 acre13 pond13 in the13 spring In

September the pond is harvested by draining the pond and seining All fish that have

reached the target size (300 mm TL) are stocked Fish that are too small to stock are split

up equally between the six remaining grow-shy‐out pond at an13 average13 density13 of about 5000

ndash 7000 fish per pond Fish are fed by hand at approximately 25 body weight split

between morning and evening feedings Fish are either fed a catfish diet made by Rangenreg

13

13

that is enriched with spirulina and krill or razorback sucker diet made by Silvercupreg

depending on availability Fish are monitored visually and by sampling using a cast net

When a large number13 of fish have13 grown to13 the13 target size they13 are13 harvested13 by13 draining

the pond and seining13 Fish are again13 sorted by hand and the largest13 fish are stocked13 Fish

that13 have not13 reached the target13 size are returned to the ponds for further grow-shy‐out13 On13

average it13 takes one to two years for fish to reach the target13 size with fish growing13 an

average of 06 mmday Target numbers for production are 12000 razorback suckers

annually (300 mm TL) The biggest difficulty in rearing razorback suckers at Bubbling

Ponds13 Fish Hatchery13 is protozoan13 parasite13 infestations13 (Ich) and13 associated13 bacterial

infections that come from13 an open spring source that is inhabited by mosquitofish

Dexter National Fish Hatchery13

Dexter National Fish Hatchery maintains four separate razorback sucker13

broodstocks13 These fish are spawned on13 site and larval13 fish are placed directly into 01 acre

ponds at a density13 of about 20000 larvae13 per pond (50 ndash 100 thousand13 per13 acre)13 Ponds

are fertilized with alfalfa13 pellets and superphosphate two weeks prior to receiving13 larvae to

produce13 natural13 feed for larval13 fish13 Ponds are13 fertilized again with alfalfa13 pellets one week

after larvae are introduced13 Fish are fed a catfish starter diet13 (sizes 1-shy‐3) made by Rangenreg

that13 is enhanced with spirulina13 and krill13 and then switched over to the razorback13 diet13 once

they are large enough to eat 1mm13 crumble Fish are fed twice a day by hand four days a

week13 at 25-shy‐60 body weight Feed ration is decreased if excess feed is seen remaining

on the13 pond bottom13 following feedings Fish are not graded or sorted during this grow-shy‐out

period Razorback suckers are harvested in the fall by draining ponds completely Fish are

sorted13 at harvest and13 distributed13 to13 other13 facilities13 for further13 grow-shy‐out depending on13

current size requirements Razorback suckers are on average 100 ndash 200 mm TL after the

first growing13 season13 and13 generally13 take13 1 -shy‐18 months for a majority of the fish to reach

300 mm TL There are 16 different species of fish maintained at Dexter National13 Fish13

Hatchery13 and13 having sufficient pond13 space13 to13 grow out separate13 groups13 of fish is the13

limiting factor for production of razorback suckers at this location

14

13

Grand Valley13 Native13 Fish Facility13

The Grand Valley Native Fish Facility maintains its own brood stock13 in13 eight13 ponds

located at the Horsethief Basin Wildlife Area in Grand Junction Colorado Fish are

spawned13 on site13 and13 larvae13 are13 reared13 indoors in fiberglass13 tanks13 at the13 24-shy‐Road13 Fish13

Hatchery13 in Grand13 Junction The 24-shy‐Road13 Hatchery13 consists of two13 separate13 recirculating13

systems that operate using de-shy‐chlorinated13 city13 water13 and two13 large13 fluidized-shy‐ bed sand

filters13 and13 rotating-shy‐drum13 filters for waste removal Fish are held in 4-shy‐foot (n=78) or 8-shy‐foot

(n=14) diameter fiberglass tanks Larval fish are started on prepared feeds immediately

after swim-shy‐up and fed exclusively razorback feeds made by Silvercupreg Fish are started on

a 0-shy‐250 micron razorback diet for the first 10-shy‐1213 days13 and13 then13 fed with13 gradually13

increasing13 feed sizes based13 on observations of feeding13 (250 ndash 400 micron 1 starter) Feed

sizes are mixed when transitioning to the next larger feed size These razorback diets are

specially sifted by Dr Rick Barrows (USDA13 Hagerman experiment station Idaho)

Razorbacks13 are13 typically eating 1mm13 extruded pellets by the time they are 35 to 4 inches

in length Fish are fed approximately 70 body weight per day initially and then gradually

reduced to 15 body weight by the time they reach the 300 mm TL target size Fish are

fed seven days13 a week using13 12-shy‐hr13 belt feeders It takes13 12-shy‐16 months to grow fish to the

target13 size in13 the hatchery13

Razorback suckers are sorted after three months and culled to about 4000 fish per

family lot Culled fish are stocked into leased grow-shy‐out ponds Stocking densities for

juveniles in these ponds is based on previous13 stocking and harvest13 rates13 and is pond

specific13 Grow-shy‐out ponds are13 harvested13 periodically13 using Fyke13 nets13 or trap13 nets13 and13 fish of

the target size are stocked Disease problems (Ich Lernea) water quality problems (low

DO) and difficulty in removing all of the fish are challenges for grow-shy‐out of razorback

suckers13 in these13 natural ponds13

Fish reared13 in the13 24-shy‐Road facility are sorted again at four to five months of age into

small and large size groups to obtain more uniform13 growth rates Batch estimates of fish

weight are done every month for each tank A group of fish are weighed and counted to

give an average weight for the tank with lengths estimated based on a lengthweight chart13

The biggest difficulties13 for growing13 out razorback suckers13 at the13 24-shy‐Road13 Fish13 Hatchery13 are13

insufficient space and water flow (oxygen) to grow fish to the target size At the Horsethief

15

13

Basin13 Ponds where broodstock13 are reared13 diseases such as Ich are problematic because

water is pumped directly from13 the Colorado River

Ouray13 National Fish Hatchery13

Ouray13 National13 Fish Hatchery maintains its own broodstock and13 spawns13 fish on-shy‐site13

Larvae are transferred from13 indoor hatching tanks to unfertilized 02 acre outdoor ponds

and stocked at densities 10000 ndash 20000 larvae13 per13 pond13 Even13 though13 outdoor13 ponds13 are13

covered with13 bird13 netting13 avian predators13 still get caught in the13 nets13 if they13 can see fish

Ponds are dyed blue13 as the13 fish grow to13 prevent avian predation13 While in the outdoor

ponds13 fish13 are13 fed a slow-shy‐sinking salmon diet made by Silvercupreg twice daily by hand

Amount of feed is based on periodic sample counts Fish are grown until late September at

which time temperatures require that all fish13 other13 than13 adult broodstock13 be13 brought

inside for the winter Ponds are drained completely and fish are sorted by hand Fish that

have reached the target size (300 mm TL) are stocked into the Green and Colorado Rivers

All remaining fish are moved indoors13 and13 held13 in three-shy‐foot (n= 30) or eight-shy‐foot (n=27)

diameter circular tanks On average it takes 12 ndash 18 months to grow fish to the 300 mm TL

at Ouray13 hatchery13

Razorback suckers are held during the winter in a recirculating system13 that

operates13 using13 two13 large13 fluidized-shy‐bed sand filters and a rotating-shy‐drum13 filter for solids

removal Fish are fed the Silvercupreg razorback diet using belt feeders There is currently

capacity13 to13 hold13 only13 20000 200-shy‐300 mm TL fish inside the facility and any extra fish13 are13

stocked13 into13 floodplain-shy‐wetlands or used for research purposes13 Ouray no longer leases

any private grow-shy‐out ponds Grow-shy‐out ponds were troublesome due to poor water quality

harvesting13 difficulties13 and13 non-shy‐native13 fish introductions13 The biggest difficulty13 for

production13 of razorback13 suckers at the Ouray13 National13 Fish13 Hatchery13 is space13 during13 the

winter to maintain large numbers of fish and high iron and manganese in the well water

that must be filtered out prior to use

16

13

Willow Beach National Fish Hatchery13

Willow13 Beach National13 Fish Hatchery receives wild-shy‐caught larvae from13 Lake

Mohave Larvae are treated for diseases with formalin and malachite green and placed in

45 ten-shy‐gallon13 flow-shy‐through aquaria13 Recirculated13 solar heated water13 22-shy‐25deg C is used to13

allow production of warm13 water fish at this traditionally cold water facility (Figiel 2003

Figiel et al 2005) Fish are fed brine shrimp nauplii to satiation every hour and after 14

days small amounts of specialized larval fish diet (Encapsulon13 Cyclopeeze13 spirulina13 and

artificial plankton) are introduced After 30-shy‐6013 days13 fish are13 transferred13 to13 six13 32-shy‐gallon13

fiberglass troughs at densities of 1000 to 1500 fish per tank and then a month later moved

outside13 to13 eight recirculating13 raceways that use a combination of well water and solar-shy‐

heated water to maintain temperatures of 22 ndash 25deg C during the summer months

When13 in13 the outside raceways13 fish are fed the razorback13 diet13 using13 belt13 feeders and

fed by13 hand13 at 10 -shy‐ 70 body13 weight per13 day Feed amount is adjusted based on sample

counts according to a feed conversion program13 developed for razorback suckers by Willow

Beach Hatchery personnel This program13 uses length and number-shy‐per-shy‐pound generated

from13 several years of razorback growth data (Figure13 1) Fish are13 sorted13 opportunistically13

and are not handled during the summer months when water temperatures are above 20degC

In 2004 the target size for stocking was 325 mm TL or greater (WBNFH 2004) with a

target13 of producing13 6000 fish per year Reaching this13 target size usually13 takes13 two13 growing13

seasons13 The biggest difficulty13 in rearing13 razorback suckers13 at Willow Beach13 National Fish

Hatchery13 is insufficient space13 to13 grow fish to13 increased13 target sizes (400-shy‐500 mm TL)

Uvalde13 National Fish Hatchery13

Uvalde13 National Fish Hatchery13 in Texas13 receives 35000 ndash 60000 razorback sucker13

fry annually in MarchApril from13 Dexter National Fish Hatchery The fry are acclimated in

bags submerged in the pond for a minimum13 of one hour and released into13 a 1 acre13 fertilized13

pond where they are reared for the remainder of the summer Fingerlings are fed a starter

razorback diet when they reach approximately 50 mm TL In AprilMay the previous year

class of razorbacks are captured from13 their over-shy‐wintering pond enumerated graded and

split into13 one-shy‐acre grow-shy‐out ponds Approximately 4000 ndash 5000 fish will be13 placed13 in each13

one acre pond for summer grow-shy‐out Fish are reared for approximately 150 days (May ndash

17

13

Oct) and fed the Bozeman razorback diet two times a day five days a week at 15 ndash 30

body weight per day based on average water temperature

Figure 1 Relationship between length and number of fish per pound

In general13 juvenile razorback13 suckers (received as fry13 during13 the previous spring)13

reach the target size of 300 mm TL in approximately 6 months In 20062007 Uvalde

produced 6000 razorback suckers 300 mm TL for introduction into the San Juan River

Starting13 in 2008 Uvalde NFH will be producing13 and distributing13 12000-shy‐ 300 mm TL

razorbacks for stocking into the San Juan River Predation from13 migrating cormorants has

occurred but timing of harvest and over wintering protection methods such as covering

ponds with netting or placing fish indoors helps to minimize losses during the cormorant

migration (November to March) Uvalde has experienced razorback mortalities because of

bacterial problems but these are usually resolved through the use of oxytetracyline

medicated feed

Overview13 of Differences in Culture Methods

Several differences were noted when conducting surveys at each of the five main

production facilities for razorback sucker (See Appendix 3) These differences include

different stocking13 and13 rearing13 densities13 (Table13 4-shy‐5) various feeding regimes and type of

18

13

lt=amp

feeds (Table 7) as well as differences in grading or sorting practices Some of these

differences are13 related13 to13 whether13 or not razorback suckers13 are13 being13 reared13 in extensive-shy‐

culture13 facilities13 (ponds) or intensive-shy‐culture13 settings13 (raceways13 o tanks)13 Some13 practices13

are unique to a single facility13 or a couple of facilities (Table 6)13 Managers at each facility13

were asked to identify the biggest13 difficulty or constraint13 that13 they experience when13

growing-shy‐out juvenile13 razorback suckers13 at their13 respective13 location13 Space constraints13

water quality and disease problems were the main factors limiting production of razorback

suckers13 at these13 facilities13 (Table13 8) Calculated or reported growth rates from13 the literature

vary widely (Table 9) and range from13 02 to 18 mmday These growth rates indicate that

juvenile razorback suckers have a very high growth potential under optimal rearing

conditions13

Table13 4 Stocking13 densities13 for larvae13 and13 fry in ponds

$amp( )(+amp-( 01-2(3(4amp56( 4amp56(+amp-( 01-2782-( $amp () + --amp +amp0amp)+amp 12-3amp ( )+amp0amp+amp --amp +amp0amp)+amp 42556789amp8 ( +amp0ampgt+amp 3amp +amp0amp+amp A-BC-Damp (E + 3amp )+ F-6ltamp ) G+ 3amp G+

Table13 5 Rearing13 densities13 at intensive13 culture13 facilities13

$amp( )amp+(($-( $0( 12(3$+( 40((amp05( 67((amp05( 8$9(407$( $amp amp())amp++-$amp 0 1 0amp2amp1amp 3amp2amp4 0544

6amp())amp++-$amp 610 021 4amp2amp47amp 3amp2amp77amp 058 9$amplt+)amp 4amp())amp++-$amp 00 1 7amp2amp77amp 851amp2amp0amp 05

6amp())amp++-$amp 610 77amp2amp1amp 0amp2amp1amp 053

19

13

Table13 6 Rearing13 practices13 that are13 unique to13 specific rearing13 facilities13 $$amp( )$+-(amp$-(0(1-amp2034( $amp()amp+( -0$(12(33+(amp(amp134$53+(amp$amp3+(6amp+(

723(843(1$8(422(6amp+(42amp(4(423(19$43( 343( lt34$53(6amp+(6(4($03(amp4+94amp(842($1$1(63$$34(amp+(63626243( =amp+(gtamp94ampA( B3(1(1$+53+C3+(amp+(1$43(1(3D0$(1(amp443(amp+(amp443( 734231(amp( B3(1(193(44(1(34amp(amp(+49E(6amp+( -E3(F3+( G3amp(1(12(amp(H3(13$(4ampE(C(IJK($$amp( A( L43(+A3(4(6303amp4(63+4ampM(66$3D3amp4$(34amp(amp(6amp+(C((4amp3( L$$8(392(

B0$+3(

N43D(13+(4($0$(12M(amp+(639$53+($0$(12(+34( G3amp(12(amp(399$4amp(4+(938A(842($(2343+(843( N443D643+(3amp(12(amp(amp34(63amp(amp(423(O$+(G03( )amp+(3(134$53+(6(4(39364(1(1A(4(44(423D(amp((D3(amp4$(+34(

Table13 7 Types of feed used at razorback sucker13 hatcheries13 $amp ()amp+-amp0- $$)1amp23 45-amp)-$5)1amp23 $amp()amp+( -amp$amp+(amp+( -amp012$3+(amp+4(amp5215$(0+( 65ampamp7(85209(+2($1(87((15315lt=(+2(

+amp+amp(amp(55$5$2gt( 21( Aamp+(amp+( )amp+(012$3+(B29(5$05$95($$2(5amp+(

199524(amp5215$(0+( 65ampamp7(85209(+2($1(87(15315lt=(+2(amplt( 29gt(51($51(amp9(2(25=(C(DD(0+(

E15amp+(Famplt2amp( G1$5(lt1lt$51(25amp=( HIJKH(Dlt1amp(15315lt=(+2(I(C2(CH(+5gt( )11$gt($511(02+(15315lt=(+2(

$1(87(15315lt=(+2(D5$$(3(lt5$$gt(02+(gt( 6lt=(511B(

L15gt( G1$5(lt1lt$51(25amp=(Aamp+( amp+(

HIJKH(Dlt1amp(15315lt=(+2(I(C2(CH(+5gt( )11$gt($511(02+(15315lt=(+2(

$1(87(15315lt=(+2($1(87($B(amp=amp( 5$Damp(+2(

M$$B(5lt9(-5$+( NO515(G1$5(219( L2+1(15ltB5gt(Aamp+(5amp+( amp$amp+(amp+(

1amp(91D(amp5$(Pamplt5$amp4( 8gtlt$34(1$amp54(5amp+(5120lt5$( $5amp=2amp()amp+(012$3+(B29(5$05$95( $$2(5amp+(19952Q(amp12152( 1+lt2amp(

$1(87(15315lt=(+2($1(87(15315lt=(+2( $1(87(15315lt=(+2(

Table 8 Factors limiting production at major razorback sucker facilities

$amp( )amp+(-0+1((2$(0amp1ampamp(-34amp( $amp()amp+( -(01$2(34+(546(amp(0amp(01amp(541(13( -741( 803(3amp41amp4(9((+ltlt1amp4(03(amp(44amp(2=(4(

+ltlt3$4(4(2amp4amp(014(1gt13=(43=( 1amp+(amp34amp( 803(3amp41amp4(1$4+(4(541(A$4B(amp+(+$C+(

7Bamp($244amp(lt(1313$4amp(B42( D1B( E41(A$4B(01$2(3+(B(66(1amp(amp+(2ampamp(

Eamp41(420141(464(1A1($$(lt6(4((2C+(amp+1( 803(3amp41amp4(1$4+(4(541(A$4B(amp+(+$C+(7Bamp(

E$$5(36( 803(3amp41amp4F(15amp(lt6(4(amp31amp$B($11(gt( 1$4(amp(ampltlt3amp4(03(amp(44amp(lt1(amp5(lt6(

GC$+( 8221(420(3amp(4(6691A1amp(051((4(410$(+(4( 661(1amp+541(020amp(4(=0(0amp+(3$F(

20

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Table9Reportedandcalculatedgrowthratesfromtheliterature

Calculatedgrow

thratesbasedon

informationprovidedinliterature

aApproximationsofmaximum

grow

thpotential(basedon

average13 maximum

sizesiffishreportedatharvest

21

13

General Information on Factors that Affect Fish Growth

Growth in fish is extremely variable and is impacted by many different

physiological and environmental factors Growth rates are known to change with size and

age sex season activity level density amount13 of living space quality and quantity of food

genetics and temperature (Brett 1979) Growth experiments conducted at different times

of year can result in growth rates that are not comparable As fish become larger their

physiological13 potential to grow decreases making determination of growth rate dependent

on the size of the starting fish and the length of the experiment (Busacker et al 1990)

Genetic factors also have great potential to influence growth rate Some species have

strains13 and13 races13 that display vastly different growth potentials (Reinitz et al 1979) All of

these factors combine to make assessment of the individual factors controlling fish growth

difficult13

Water temperature is probably the most important variable affecting growth rate13

All of the basic functions that affect growth such as feeding digestion and metabolism are

temperature-shy‐dependent13 Growth13 is inseparably13 tied13 to13 bioenergetics13 and13 therefore13 also13

tightly tied to temperature When temperatures are below optimum daily temperature

fluctuations can stimulate growth Photoperiod is also commonly linked to water

temperature and can influence growth rates in fish (reviewed in Brett 1979)

Fish density13 is known to13 affect growth13 and13 can alter13 growth13 rates13 in several ways13

Fish that exhibit strong territorial behaviors13 or natural schooling tendencies13 will

experience reduced growth if densities are too high or too low (Brett 1979) Dominance

hierarchies where some fish feed more aggressively than others can also lead to high

variability13 in growth13 rates13 (Koebele13 1985) Crowded13 conditions13 also13 cause physical

interference13 between13 fish and13 poor water13 quality13 which13 reduces13 growth13 (Busacker13 et al13

1990) The effects of fish numbers space and feeding opportunity are frequently correlated13

and often13 difficult13 to distinguish (Brett13 1979)13

It is impossible to study the effects of environmental factors on growth without also

evaluating feed rations (Brett 1979) Amount of food quality of the diet particle size

number of feedings per day and time of feeding have all been shown to affect growth

(Busacker et al 1990) In controlled laboratory studies food is usually fed ad libitum13

22

13

(constantly available) and other variables are altered to assess impacts of environmental

factors13 on growth13 These studies13 are13 usually13 conducted13 in tanks13 or raceways13 because13

researchers must verify that food is constantly available to the fish which is difficult to do

in large pond environments where the fish and the bottom13 are often not visible (Busacker13

et al13 1990)

Specific Information13 o Razorback13 Sucker13 Growth

Variable13 growth

Growth in razorback suckers is naturally highly variable and may be a function of

their evolutionary history (USFWS13 2002)13 Minckley (1983) speculated that13 wide size

variation in a single cohort of razorback suckers may be adaptive with fast-shy‐growing13 fish

that13 reproduce at a young13 age surviving13 better in13 high discharge years and slow-shy‐growing13

smaller fish surviving better during drought periods This highly variable growth rate

makes rearing razorback suckers in a production setting difficult because fish from13 a single

cohort do not reach the target stocking size simultaneously One of the major tasks for

aquaculture is to maximize both individual growth and total production13 (Gerking13 1978)13

This becomes more difficult when the species being cultured exhibits highly variable

growth13 rates13 because of genetic influences as is the case with razorback13 suckers13

Razorback13 sucker growth13 is typically very13 rapid13 during13 the first13 year of life13 and then13

declines with age First year growth can be as low as 50 mm and as high as 350 mm (Valdez

et al13 1982 Minckley13 1983 Mueller13 1995) Razorback sucker13 grow rapidly13 for

approximately the first five or six years of life and then growth slows13 (McCarthy13 and13

Minckely 198713 Tyus 199813 Minckley et13 al 1991)13 Growth of older individuals in13 extant13 wild

populations is very13 low (Minckley 198313 Tyus 198813 Modde13 et al 1996)13 Wild growth13 rates

for mature adult fish in Lake Mohave based on PIT tag recaptures were often too small to

be accurately measured for both males and females over the time period of 1987-shy‐199713

(Marsh and Pacey 1998) This information suggest it will take substantially longer to rear

fish to13 increasingly13 larger13 stocking13 sizes (40013 ndash 500 mm TL) than it did to reach the target

size of 300 mm TL

Growth in ponds

23

13

One of the main strategies for maintaining genetic refugia and self-shy‐sustaining13

populations of razorback13 sucker in the lower Colorado13 River basin13 is to rear razorback13

sucker13 larvae13 in production13 ponds until they13 are13 a suitable13 size for stocking13 (USFWS13 2004)

Pond culture has proven useful to promote rapid growth of juvenile razorback suckers

(Kaeding and Osmundson 1989) Marsh (1994) reported that growth rates of razorback

suckers13 reared13 in golf-shy‐course13 ponds exceeded13 the13 best growth13 rates13 obtained13 under

intensive13 culture13 conditions13 at federal hatcheries13 especially13 during the13 first several years13

of life Growth rates in these semi-shy‐natural ponds are also comparable to estimated growth

rates13 of juvenile13 wild13 fish (McCarthy13 and13 Minckley13 1987) Modde13 and13 Haines13 (2005)

reported13 the13 greatest growth13 rates13 in the13 largest and13 deepest floodplains13 with13 the13 greatest

amount of submergent vegetation but excellent growth and survival of fish in a grow-shy‐out

pond is of little value if there is not an efficient way to collect the fish from13 the pond

(Kaeding and Osmundson 1989)

Temperature13

Bulkley and Pimentel (1983) used shuttle boxes in the laboratory to determine a

temperature preference13 for razorback suckers13 of 23-shy‐24degC13 In13 their13 studies13 razorback

suckers were found to avoid temperatures below 118 degC or above 286 degC Razorback

suckers at Bubbling Ponds Hatchery are more active in the spring and feed better as

photoperiod increases even prior to water temperatures rising (Frank Agygos personal

communication) Table 3 briefly summarizes water temperature data from13 each facility

Detailed seasonal water temperature profiles are not currently available for many

razorback grow-shy‐out sites13

Density13

Extensive studies have been conducted on commercially important species to

evaluate stocking densities and feeding rates that maximize production For these species

controlled experiments under laboratory conditions have established relationships

between temperature density and feed ration on growth (Brett 1979) but this information

is sporadic13 or non-shy‐existent for razorback suckers13 (Bays13 et al13 2005) Fish culturists13 with13

24

13

experience13 rearing13 razorback suckers13 typically13 have13 target stocking13 densities13 that13 they use

(Tables13 4 -shy‐ 5) These stocking densities have largely been determined over time by trial

and error These approximate stocking densities provide a good starting point for more

controlled13 types13 of replicated13 pond studies13

Feed ration

Razorback13 suckers are currently13 being13 fed a wide variety13 of prepared diets (Table 7)

that range from13 a slow-shy‐sinking salmon feed manufactured by Silver Cupreg to a spirulina

and krill-shy‐enhanced catfish feed made by Rangenreg Most locations are feeding 20 ndash 50

body13 weight per13 day13 Methods13 for culture13 of razorback sucker13 larvae13 in intensive13 settings13 at

fish hatcheries are well documented (Figiel 2005) and various larval fish diets have been

evaluated13 (Tyus and13 Severson 1990 Severson et al13 1992) but no standardized13 procedures

are used for feeding13 larval13 fish in13 intensive settings13

Razorback sucker larvae are also effectively reared in pond environments using

natural foods supplemented with larval fish diets and survival is high when no predators

are present13 (Mueller 2006)13 Growth rates for larval13 and early juvenile razorback13 suckers

may increase with pond fertilization Diet and physiological studies on wild razorback

suckers indicate that they feed on plankton as well as benthic organisms during their entire

life (Marsh 1987) Artificially fertilizing ponds may greatly increase production capacity

and growth rates for razorback13 sucker (Papoulias and Minckley13 1992) and warrants

further13 investigation13

Handling stress

Handling stress13 has13 been shown to13 influence growth13 rates13 Paukert13 et al (2005)

found that growth of bonytail chub was reduced by 26when compared with controls

after being13 repeatedly13 captured and handled in13 hoop13 nets13 Handling13 effects are likely13 to be

similar for razorback suckers that are repeatedly13 captured and sorted in13 a hatchery13 setting13

Razorback suckers that are handled at Willow Beach National Fish Hatchery will commonly

not eat for two weeks after handling (John Scott personal communication) This creates a

difficult situation13 for production13 facilities because13 fish13 need to be sorted to ensure13 large13

25

13

aggressive fish do not interfere with growth of smaller individuals but frequent handling

and sorting13 causes stress related reductions in13 growth13

Measuring Growth in Captive Fish

Weight is the traditional measure used to estimate growth or production in

aquaculture settings13 Groups of fish are typically13 weighed and an average individual13 weight13

is computed (Busacker et al 1990) Although this method is often logistically the easiest it

may not be the most informative for species with highly variable growth rates like

razorback suckers especially when target lengths must be reached before fish can be

stocked Weight can also be highly influenced by things like stomach fullness or

development of gonads (Busacker et al 1990) Condition factor or relative weight can also

be used to assess growth of fish but these tools may be more robust predictors of fecundity

than of growth (Anderson and Neuman 1996) For some species sexes need to be

distinguished because males and females may differ in morphology (Anderson and

Neumann 1996) Mueller (2006) analyzed growth rates based on PIT tag recaptures of 86

razorback suckers13 in High13 Levee Pond13 and13 found13 that differences13 in growth13 do not appear13

to occur until fish are over 450 mm TL at which time growth rate in males slows while

females continue to grow at a slightly higher rate This would indicate that sex may not be

an important factor to consider when examining growth rates unless the target grow-shy‐out

size is above 450 mm TL

The best measures of growth are often determined from13 the length and weight of

individuals rather than from13 groups of fish (Anderson and Nuemannn 1996) because

individual growth rates give better estimates of confidence and variance (Busacker et13 al

1990) Length frequency analysis or recapture of previously marked individuals of a known

size is likely to yield the most useful information for razorback sucker growth The success

of any of these methods depends on proper sampling procedures that are representative of

the population as a whole (Busacker et al 1990) Sampling methods that are known to be

size-shy‐biased such as trammel nets (Mueller et al 2004) or cast nets should not be used when

trying to measure growth rates13

26

13

Conclusions

For razorback sucker survival is largely associated with stocking size Additional

focused13 research13 is therefore13 needed to13 identify13 ways13 to13 increase13 growth13 rates13 of captive-shy‐

reared13 razorback sucker Growth13 rate13 in fish is controlled13 by many factors including fish

size and age temperature density and feed ration which can all be highly correlated

Growth of razorback suckers is also inherently variable which makes the task of identifying

the key factors that13 affect13 growth in13 captivity even more difficult The focus at most

razorback rearing facilities13 is production so the13 types13 of data that are13 collected13 are13 often

insufficient for detailed13 evaluations13 of individual rearing13 practices13 on growth13 Surveys of

existing13 razorback sucker13 rearing facilities indicate that culture methods vary widely and

the types of growth data13 that13 are collected are not13 standardized13 Replicated studies with

detailed information on rearing location water temperature initial stocking size stocking

density and the sizes of all fish at harvest are needed in order to compare the effects of

individual rearing practices on growth This type of research will ultimately provide both

time and cost-shy‐savings to production facilities by reducing the amount of time necessary13 for

razorback sucker to reach stocking size improving overall production efficiency

Optimum13 rearing densities for razorback sucker larvae and juveniles remain to be

determined Current stocking densities will be very useful as starting point for more

detailed studies and although optimum13 rearing densities are likely to be site-shy‐specific13

replicated studies on density will provide a valuable reference for hatchery managers

Frequency13 of sorting is another13 area that needs13 further13 research Frequent

handling13 and13 sorting13 can13 cause13 stress-shy‐related13 reductions13 in growth but not sorting can

create dominance hierarchies that further reduce growth rates of subordinate individuals

The effects13 of sorting13 on overall fish growth13 in both13 pond and13 intensive13 culture13

environments warrant further investigation Research techniques for these types of

experiments are well understood and typically utilize a matrix of replicate ponds per

variable (Bays et al 2005) In every case accurate and complete records of sampling

procedures and data collection are needed in order to interpret data and make inferences

about13 growth rates (Busacker et13 al 1990)13

27

13

Additional research is also needed to evaluate long-shy‐term13 survival of stocked fish

reared in ponds compared to fish13 reared13 in intensive13 culture13 facilities13 Exercise13

conditioning13 and predator-shy‐recognition training may also increase survival of stocked fish

and be more economically feasible than rearing fish to increasingly larger sizes prior to

stocking13 The success13 of traditional fish hatchery programs is measured largely by the

number of fish stocked but hatchery programs for endangered species must measure

success in terms of long-shy‐term13 survival and species recovery (Brannon 1993 Anders 1998)

A specific list of research recommendations follows

Specific Research13 Recommendations13

bull Use replicated studies13 to establish optimum stocking13 densities13 for ponds13 and

tanks13 that can be used as13 a starting13 point for site specific refinement

bull Determine if sortinggrading13 improves13 overall growth rates13 in both ponds13 and

intensive culture facilities13

bull Investigate the use of artificial fertilizers13 to improve growth of both juvenile

and adult razorback suckers13 in ponds13

bull Determine if the razorback sucker diet gives13 better growth rates13 than cheaper

catfish or salmon feeds

bull Evaluate growth rates13 and production potential of new intensive culture

methods13 such as13 large circular tanks13

bull Evaluate13 long-shy‐term survival of fish produced from raceways13 and circular tanks13

compared to fish reared in ponds13

bull Evaluate more effective means13 of treating13 fish diseases13

bull Evaluate factors13 other than size that may increase post-shy‐stocking13 survival such

as13 exercise conditioning13 predator recognition training or rearing13 under more

natural settings13

28

13

II The Effect of Disease Treatments on Razorback Sucker

Growth

Section13 SummaryFormalin copper sulfate potassium permanganate and13 salt are all chemicals commonly13 used13 to13 treat13 Ichthyophthirius multifiliis outbreaks in captive razorback sucker (Xyrauchen13 texanus) Weexposed 190 juvenile13 razorback suckers (127 ndash 26 mm TL) to13 5 5-shy‐day treatments with13 each13 chemical to evaluate the effects13 these chemicals13 may have on growth Fish grew an average of23513 mm TL13 during the month13 study period Fish treated with formalin grew on average13 29mm TL (03 mmday) while fish treated with copper had the lowest growth averaging 20 mmTL (021 mmday) No significant differences in13 growth were observed among fish treatedwith any of the chemicals compared to untreated fish (pgt005) Reductions in growth13 as aresult of repeated chemical treatments are not likely the cause of differences in growth ratesamong13 facilities that raise razorback suckers Repeated chemical treatments may13 have otherimpacts to overall13 fitness or long-shy‐term survival but13 these effects were not13 evident13 in our study

29

13

Introduction

Preservation13 of razorback sucker13 (Xyrauchen texanus) currently13 depends on captive13

rearing and stocking programs until permanent solutions to factors that prevent wild13

recruitment are found Low survival of stocked razorback suckers (Brooks 1986 Marsh

and Brooks 198913 Marsh and Pacey13 2005) has caused target13 sizes for stocked fish to

steadily increase in efforts to reduce predation mortality (Marsh et al 2005 Schooley and

Marsh 2007) Rearing fish to larger sizes at hatcheries comes with increased costs and

creates the need to evaluate husbandry and rearing practices that may affect fish growth

Formalin copper sulfate potassium13 permanganate and salt are all chemicals

commonly used at razorback sucker rearing facilities to treat outbreaks of the protozoan

parasite13 Ichthyophthirius multifiliis ldquoIchrdquo is one of the most pathenogenic diseases of

cultured13 freshwater13 fishes (Matthews13 2005) and causes large13 losses in captive13 populations13

of endangered razorback sucker Each of these chemicals used to treat Ich only kill the free-shy‐

swimming life stage of the parasite13 requiring13 repeated doses over several13 days depending13

on water temperature These chemicals treatments are needed to prevent loss as a result

of disease outbreaks but the cumulative effects repeated disease treatments have on

growth13 are13 unknown

Copper13 sulfate13 has13 been shown to13 significantly13 reduce13 growth13 of channel catfish13 in

production13 ponds (Rabago-shy‐Castro13 2006) but it is unknown whether13 razorback suckers13

experience similar reduced growth following copper treatment Quantifying the impacts of

disease treatments on growth will help to interpret the wide differences in growth rates

observed13 at various13 razorback sucker13 production13 facilities13 throughout the13 southwest

(Ward et al 2007) If one chemical is found to have less detrimental impacts on growth

than another then it may be preferred for use as a disease treatment We evaluated growth

rates13 of razorback suckers13 under13 replicated13 and13 controlled13 conditions13 to13 assess13 effects13 of

repeated formalin copper sulfate and potassium permanganate and salt treatments on

growth13

Methods

We captured 190 juvenile razorback suckers from13 ponds at Bubbling Ponds Fish

Hatchery AZ using hoop nets or cast nets All fish were of the same age class and

30

13

averaged 179 mm total length (TL) (range13 = 127 ndash 262 mm TL)13 These fish were13 offspring13

of captive13 razorback sucker13 broodstock held13 at Dexter13 National13 Fish Hatchery13 NM13 (2007

year class) All fish were tagged with passive integrated transponder (PIT) tags and

quarantined for one month prior to the experiment to allow fish to recover from13 tagging

and become accustomed to being held in circular tanks

At the beginning of the study all fish were weighed measured and scanned for

individual tag numbers with 19 randomly selected fish placed into each13 of 10 8-shy‐foot

diameter circular tanks (Figure 2)13 Each13 tank contained13 two13 airstones13 and13 an13 individual

biofilter with a recirculating water pump (31 litersminute) that had been operating for

at least 1 month prior to the experiment to allow bacterial colonies to become

established Two tanks were designated as a control and did not receive any chemical

treatments while the other eight tanks received formalin copper sulfate potassium13

permanganate or salt treatments at two week intervals (two tanks per chemical

treatment) Formalin copper sulfate and potassium13 permanganate were treated at 1 part

per million (ppm) and salt was applied at 30 parts per thousand (ppt) These treatment

rates are commonly used to treat13 razorback13 suckers for ich at Bubbling13 Ponds Fish13

hatchery (Frank Agygos personal communication)

Figure 213 Photo ofexperimental tankswith individualbiofilters and aeration

31

13

Each treatment consisted of a series of doses applied on Wednesday Thursday and

Friday with a 90water change between each dose Biofilters were removed from13 all

tanks and held in a separate holding facility during treatments and then replaced on the

Monday following treatments after a 90water change This schedule allowed fish to be

exposed to chemical treatments for 5 consecutive days without water quality deteriorating

This 5-shy‐day chemical treatment was repeated every two weeks from13 July to October (97

days)13 for a total of 5 5-shy‐day treatments Water temperature in the treatment tanks ranged

from13 13degC (55degF) to 32degC (91degF)

Fish were fed a fixed ration of commercial razorback diet (Silvercup 4mm13 pellet)

once daily13 (2 percent body13 weight per day13 as calculated13 by13 average initial fish weight)13

At the end of the experiment all fish were again weighed measured and scanned for

individual tag numbers Growth of fish in each treatment group was compared using

analysis of variance (ANOVA) Any mortalities13 that occurred during the13 study13 were13

replaced with previously quarantined fish of equivalent size to maintain equal densities in

each13 tank13 but growth13 data was13 only13 recorded for fish which13 survived13 the13 entire13

experiment

Results

Fish at the13 start of the experiment averaged 179 mm TL (Range13 = 127 ndash 262 mm)

with no significant differences in fish length among treatment groups (F(4189) = 00183 p

gt 0999 ANOVA) On average fish grew 235 mm TL (024 mmday) during the 3 month

study13 Fish in tanks13 treated with formalin had the highest growth averaging 29 mm TL (03

mmday) while fish in tanks treated with copper had the lowest growth averaging 20 mm

TL (021 mmday) Fish in the control tanks averaged 213 mm TL in growth (022

mmday) (Figure13 3)13 Formalin-shy‐treated fish grew13 significantly faster than13 any other

treatment group but no13 significant differences in growth13 in length13 or weight were13

observed among fish treated with any of the chemicals compared to untreated (control)

fish (pgt005 ANOVA)

32

13

Figure 313 Average growthof razorback suckersexposed to a series of 5 5-shy‐day chemical treatmentsover a 97-shy‐day13 periodError bars representstandard error

Discussion13

Growth13 rates13 observed13 in our study13 (021 ndash 03 mmday) are low compared to those

reported13 in other13 studies13 of razorback sucker13 growth13 (0213 ndash 18 mmday) (Ward et al

2007) Using recirculating water systems for our study required filters to be removed and

replaced during treatments Stress to fish caused by removing and replacing filters within

the tanks as well as repeated water changes may have led to overall higher stress and

reduced growth rates compared to those reported for unconfined fish Growth in fish is

highly variable and is affected by many different physiological and environmental factors

including fish size density temperature amount of space and food (Brett 1979) We

strived to control each of these factors but other factors may have also influenced growth

in our experimental tanks During mid-shy‐summer water temperatures in the treatment

tanks reached 32degC (91degF) At these warm13 temperatures fish are very susceptible to

bacterial13 infections13 The slightly higher growth exhibited by fish in the formalin and

potassium13 permanganate treatments may have been the result of these two chemicals

33

13

being effective at controlling bacterial infections The differences in growth we measured

among treatment groups were not statistically significant and do not appear13 biologically13

meaningful during the relatively short duration of this study (97 days) although the

cumulative effects of slightly reduced growth could be biologically meaningful over longer

time frames

Reductions in growth13 as a result13 o repeated chemical treatments are not likely the

cause of differences in growth rates among facilities that raise razorback suckers

Repeated chemical treatments may have other impacts to overall fitness or long-shy‐term13

survival but these13 effects13 were13 not evident in our study It is more likely that the parasite

outbreaks themselves are the cause of different growth rates among razorback rearing

facilities rather than the chemical treatments used to treat the parasites We recommend

that hatchery managers continue to use the chemicals that are most effective at controlling

ldquoIchrdquo13 at their individual13 facilities

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower Colorado Rive Multi-shy‐species13

Conservation Plan under Work Task C10 We thank Ty Wolters and Tom13 Burke for their

support of this research and Frank Agygos and Dave Billingsly of the Bubbling Ponds Fish

Hatchery13 for their13 technical assistance13 and13 help with13 collecting13 fish

34

13

III13 Razorback Growth Rates at Bubbling Ponds ndash 2009-shy‐2011

Section13 SummaryExperimental studies at Bubbling Ponds Fish Hatchery AZ have strived to understand

factors that affect razorback sucker growth in captivity and identify ways to improve growthrates and maximize size at release Rather than performing experimental studies that wouldrequire major13 rearrangement (and likely reduced production)13 of hatchery operations our13 studies13 used normal variation in production techniques13 and practices13 to isolate factors13 thatmay modify growth rates

Our initial work identified razorback13 growth rates in13 lined ponds at standard fishdensity as 026 to13 028mmday (789 to 843 mmmonth) No significant differences in growthrate were observed among fish that had been in the pond only during the winter13 periodcompared to fish that had been in the pond the entire year indicating that water temperatures13 at Bubbling Ponds are high enough to allow fish to incorporate feed effectively year-shy‐roundHowever these growth rates are lower than most values reported from the literature fromnatural or semi-shy‐natural pond environments No significant differences in13 growth rate wereobserved13 between large and13 small fish13 within the 150 ndash 29 mm TL13 size range Additional worksuggests13 that razorback suckers13 tagged at over 300 mm TL had reduced growth rates (024mmday 73 mmmonth) as would be expected according to a typical Von13 Bertalanfy growthcurve although growth rates13 were only slightly less13 than the average growth rate for thehatchery (027513 mmday 82513 mmmonth)

Sorting13 to13 separate small fish from large fish after the first year of growth is practicedesigned13 to allow smaller fish to ldquocatch uprdquo to larger fish We found that13 this technique doesappear to13 improve growth rates of smaller fish Growth rates of sorted small razorback suckers(029 mmday 87mmmonth)13 were equal to that13 of larger13 fish (028 mmday 8413 mmmonth)indicating that sorting may have helped to offset their original slower growth trajectory

Bubbling Ponds Fish Hatchery grows razorbacks in 6 long deep ponds lined with heavyplastic 2 long deep13 earthen13 (unlined) ponds and three wide shallow earthen ponds The wideshallow ponds13 have historically produced very large fish at low density but have been found tomaintain much lower fish numbers than deeper ponds We found13 that growth13 rates ofrazorbacks kept at high density (4-shy‐700013 fish)13 in a wide shallow pond grew extremely slowly(024 mmday 726 mmmonth) This growth rate is among the slowest of any fish over theyears of our study and demonstrates that13 though the large ponds may produce large fish at lowdensity13 they are unable to overcome high13 fish13 densities

Finally one of the major factors influencing13 fish13 growth13 in hatcheries is disease onemajor summer-shy‐time disease at13 Bubbling Ponds is the ectoparasite Ich (Ichthiopthirusmultifiliis) To investigate the impact Ich has on razorback growth we eradicated fish from thespring and water conveyance ditch that supplies13 water to the hatchery using Rotenone This13 restoration effort was fairly short-shy‐lived (Ich returned to the hatchery within four months) but

35

13

growth13 rates of fish13 reared for four months without Ich present (031 mmday 92 mmmonth)were significantly higher than the following 8 months of growth for those same fish (022mmday 65 mmmonth) This disease-shy‐free growth rate is in fact faster than any13 otherprevious growth rates observed at the hatchery in our study

We conclude that growth rates at the Bubbling Ponds Fish Hatchery are likely as highas possible given the pond densities required to13 meet production goals and the Ich-shy‐infestedwater13 that feeds the facility Sorting practices are successful in helping as many fish as possiblereach stocking length as fast as possible Unlined ponds may be able to grow large fish at lowdensities but whatever factors allow for that growth13 are not able13 to overcome13 high fish densityThus the large lower ponds at Bubbling Ponds may be better utilized via renovation to13 deepenand line them

Disease is the most important factor limiting growth as may be expected to be the caseat many13 hatcheries While the spring renovation was not13 a complete success13 the dramaticreduction of fish populations in that habitat was enough to dramatically13 reduce13 the13 occurrenceof Ich at the hatchery13 Such open spring13 systems feeding a hatchery are a misfortune that canbe expected to transmit disease so we suggest that renovating the spring again to combat13 IchImproved techniques to divert water from13 the springs and more throuough treatment ofstream-shy‐side vegetation may improve the success of chemical treatment Successful renovationwould likely both improve growth rates and reduce chemical costs associated with treating Ichoutbreaks Even13 if complete renovation13 is impossible or impractical an13 effort to reduceinvasive fish density in the springs13 which act a vector for the parasite(and thereby reduce thelikelihood of13 Ich being transmitted into ponds) may still13 show dramatic improvements

36

13

Introduction

Conservation efforts13 for razorback sucker13 (Xyrauchen texanus)13 currently13 depend on

captive rearing and stocking programs Low survival of stocked razorback suckers (Brooks

1986 Marsh13 and13 Brooks13 1989 Marsh13 and13 Pacey13 2005) has13 caused13 target sizes for stocked13

fish to steadily increase in efforts to reduce predation mortality13 (Marsh13 et al13 2005

Schooley and Marsh 2007) Rearing fish to larger sizes at hatcheries comes with increased

costs and creates the need to evaluate husbandry and rearing practices that may affect fish

growth13 We evaluated growth13 rates13 of individual razorback suckers13 in ponds13 at Bubbling

Ponds Fish Hatchery13 using Passive Integrated13 Transponder (PIT) tags13 to13 obtain13 precise

growth information for individual fish so that valid comparisons of growth rates as related

to rearing practices can be made

Due to the critical nature of the razorback sucker stocking program we did not

design experimental studies that would require major rearrangement and potentially

reduce production of hatchery operations Instead our studies used normal variation in

production techniques and practices to isolate factors that may modify growth rates

Though this methodology dramatically limits replication and may limit our ability to

directly13 attribute13 differences in growth13 rates13 to13 the13 variables13 we13 investigate13 we13 were13 able13

to accomplish research goals without altering hatchery operations or impacting

production

From13 2009 through 2011 we conducted a series of observational13 growth13 studies to

determine growth rates of individual razorbacks at Bubbling Ponds The first set of

experiments included13 identifying13 growth13 rates13 in lined13 and13 unlined13 ponds determining

growth13 rates13 of fish at different13 sizes13 in13 relation13 to sorting13 practices and monitoring

razorback growth rates after removing the source of the ectoparasite13 Ich (Ichthiopthirus

multifiliis) from13 the hatchery water source13

Razorback growth rate in lined ponds

Our first growth study documented individual growth rates at normal density in 11

million gallon lined ponds13 over two13 years13 This is the standard13 grow-shy‐out process for

razorbacks13 at Bubbling Ponds We monitored growth of fish for a variety13 of sizes and13 the13

37

13

amount of time in a pond during the growing season These13 data give a snapshot of growth13

rates13 at the13 facility13 and13 provide13 the basis for comparisons throughout our study

Growth rate13 in an unlined pond

In addition13 to 6 ponds lined with heavy plastic13 sheeting13 Bubbling Ponds Fish13

Hatchery maintains two narrow and deep (same dimensions as lined ponds13 Figure13 4)13 and13

three large13 shallow unlined ponds These earthen13 ponds typically have vegetation and

associated aquatic invertebrates that may better simulate natural environments by

providing cover and improved food diversity or quality Therefore these unlined ponds

may be expected to produce higher growth rates and potentially improved survival that is

more similar to growth rates observed in more natural grow-shy‐out facilities13 Historically13 the13

large13 shallow13 ponds have produced very large fish when13 utilized at low13 fish density13 The

narrow13 deep earthen13 ponds are13 used to grow13 fry13 at high density in their first13 year of life

The major downside to unlined ponds is the difficulty in harvesting fish where a lined

pond might take 8-shy‐1013 people13 a half13 day13 to13 harvest13 lined13 ponds13 require13 intensive13 weeding13

to allow seines to be pulled and therefore require many more personnel-shy‐hours13 In addition13

to harvest challenges the shallow earthen ponds tend to suffer from13 dissolved oxygen

crashes during the summer Unlined ponds also may maintain higher13 populations13 of non-shy‐

target species such as bluegill sunfish mosquito fish and bullfrog tadpoles We measured

growth rates of suckers in a large shallow earthen pond for comparison to growth in lined

ponds13

Figure13 4 Lined13 and13 earthen ponds13 of similar dimensions (approx 1000000 gallons first

and second panels) and a large13 shallow13 earthen13 pond (third panel)

38

13

Effect of sorting on growth

Razorback13 suckers13 are13 currently13 sorted13 after their first13 year of growth13 They are13

typically removed from13 one of the13 upper earthen13 ponds and13 split into13 two13 lined13 ponds for

subsequent grow-shy‐out13 The larger13 fish (gt approximately 140 mm) are placed into one pond

and the smaller individuals in another It is possible that the larger fish were more

aggressive or adept13 at taking food so this sorting process is intended to allow smaller fish

to improve their growth rate

Effect of Ich on razorback sucker growth rates

We13 evaluated13 growth13 rates13 of razorback sucker13 in the13 presence13 and absence of the

ectoparasite13 Ich (Ichthiopthirus multifiliis) Ich outbreaks can occur in wild populations13 but

hatcheries13 have13 proven excellent locations13 for Ich because13 of very high fish densities13 which13

facilitate13 the13 transfer13 of Ich13 between13 fish This common fish parasite causes direct mortality13

to razorback13 suckers as well13 as secondary bacterial13 infections13

The open spring and13 ditch13 which13 provides water to the Bubbling13 Ponds Hatchery

has long13 been infested with mosquitofish (Gambusia affinis) that harbor13 the13 Ich parasite13

and allow13 it13 to enter the hatchery with incoming13 water13 The solution13 to13 the13 Ich problem13

was to remove the mosquitofish host using13 Rotenone Razorback13 sucker growth13 rates were13

then tracked in13 the absence of this parasite for 4 months and compared with growth rates

after Ich returned to the pond and from13 previous years

Methods

Razorback growth rate in lined ponds

On May 14 2008 141 razorback suckers were tagged with 12 mm PIT tags (1342

kHz) and placed in Pond 3 (approximately 1100000 gallons13 Figure13 4)13 at Bubbling13 Ponds

Fish Hatchery Fifty-shy‐three of these tags were recovered two months later when a large

Ichthyophthirius multifilis (Ich) outbreak killed many fish in the pond On October 15 2008

an additional13 145 PIT tagged13 fish were13 also placed into Pond13 3 On13 May13 14 2009 Pond13 3

was harvested and a total13 of 141 PIT tagged fish were recovered13 Of the tagged fish13 26 fish

had13 been13 in the13 pond since May13 of 2008 (378 days13 o growth) and 115 had been13 in13 the

39

13 40

pond since October13 15 2008 (211 days13 of growth) Numbers of fish in Pond 3 after the Ich

outbreak and for the majority of the period of growth were between 3 000 and 4000 fish

A Hobotempreg temperature13 logger13 was13 also13 installed13 in Pond 3 one meter below the water

surface13 near13 the13 outflow and13 recorded water temperature every 3 hours to allow analysis

of the effects of water temperature on growth rate (Figure13 5) This Hobotemp data is

representative of other pond temperatures throughout this study

In a second experiment 210 adult13 razorback suckers13 were13 PIT tagged13 on13 May 14

2009 and13 placed13 into13 Pond13 3 upper to13 evaluate13 growth13 rates13 of larger13 razorback suckers13 at

Bubbling13 Ponds Hatchery13 under current13 rearing13 conditions13 Size of these fish at tagging13

was (mean = 285 mm range = 205 ndash 396 mm) These fish remained in the pond for 257

days and were harvested on Jan 25 2010 to provide information on growth rates of larger

razorback suckers13 under13 current rearing conditions

Figure 513 Temperatures (degC) inrearing pond at BubblingPonds Hatchery from July toSept 2009 (top graph)13 andfrom Nov to Dec 2009 (Lowergraph) Temperaturesrecorded with a Hobotempregremote data logger13 every 3hours

13

Growth rate13 in an unlined pond

To document razorback sucker growth in earthen ponds we introduced13 225 tagged13

razorback suckers13 into13 Pond13 1 lower13 (Figure 4) in February 3 2010 Additional tagged fish

from13 other studies were added to the pond throughout the growing season and the density

of 1 lower reached a maximum13 of nearly 7000 fish in early summer 2010 Density was

reduced to approximately 6000 fish by capturing fish with hoop nets on June 3 2010 54 of

these fish were tagged fish and returned to 1 lower after being weighed and measured The

pond was harvested on January13 2713 2011 and a total13 of 254 tagged fish out13 of 4296 fish

total were removed from13 the pond The pond was harvested on January 27 2011 (358 days13

of growth) and the tagged fish were weighed and measured Total number of razorbacks in

the pond at harvest13 was 4296

Effect of sorting practices on growth rates

On March 1113 200913 Pond13 5 upper was13 harvested13 and13 split into13 two13 separate13 groups

Two hundred of the smaller fish (average size = 122 mm TL) were PIT tagged and placed

into13 Pond13 7 upper and13 200 of the13 larger13 fish (average = 160 mm TL) were PIT tagged and

placed int Pond13 8 upper Density13 in Pond13 7 was13 4500 fish and13 in Pond13 8 there13 were13 6500

fish These ponds were then harvested after 1 year and growth rates were compared to

give information on the effects of current sorting practices Hobotempreg temperature

loggers were installed in13 Ponds 7 and13 8 during13 the13 grow-shy‐out period with13 water13

temperature recorded every 2 hours13 (Figure13 6)

Effect of Ich on razorback sucker growth rates

Bubbling Ponds spring was treated with Rotenone (CFT Legumine 5) at a

concentration of 2 ppm13 to remove all mosquitofish from13 the spring The treatment

consisted of two treatments 6 hours in duration on two consecutive days (April 12 -shy‐ 13)

using13 drip13 stations13 and13 backpack sprayers13 followed13 by13 an13 additional 6 hours13 of

detoxification using sodium13 permanganate Although 12 mosquitofish were captured in the

spring pond the week following the treatments subsequent minnow trapping (20 traps

checked13 daily13 for 3 weeks) did not capture any additional fish until August 11 2010 when

41

13

juvenile mosquitofish were again detected in the spring pond Minnow traps have

subsequently been set daily with several hundred individuals removed To evaluate if Ich

was also again present in the spring we captured 15 mosquitofish from13 the spring pond on

three separate days and placed them13 in an aquaria at 25 degC with 5 longfin dace known to be

free of Ich These fish were monitored for 2 weeks with no signs of Ich developing This

indicates that even though mosquitofish have returned to the spring pond the parasite is no

longer present13 although how13 long13 this condition13 will13 persist13 is unknown13

On May 1113 201013 200 juvenile razorback13 suckers were harvested out13 of Pond 5

upper (2009 year Class from13 Dexter National Fish Hatchery) and were PIT tagged and

placed into Pond 8 to evaluate if growth rates at bubbling ponds hatchery have improved

following the renovation of the spring and the removal of the Ich parasite Unfortunately13

on Sept13 8 2010 Ich was13 again13 detected13 in Pond 8 and the pond was immediately seined

and 74 tagged fish were measured to obtain growth information for the 4-shy‐month period

during13 which13 the13 pond13 was13 Ich-shy‐free13

Figure13 6 Temperatures (degC) in rearingponds 7 and 8 at Bubbling Ponds Hatchery13 from March 2009 ndash March 201013 pond 7(top13 graph)13 and13 pond 8 (Lower13 graph)13 Temperatures recorded with a Hobotempregremote data logger every 3 hours

42

13

Results

Growth in Lined Ponds

Razorback suckers13 that had been13 in13 Pond 8 upper for the13 entire13 year13 grew an13

average of 0263 mmday (789 mmmonth) and razorback suckers that had been in the

pond for 7 months (Oct -shy‐ May) grew13 on13 average of 028 mmday (843 mmmonth) (Figure13

7) These growth13 rates13 did not significantly13 differ Fish density13 in Pond 3 during13 the13

majority of the growth period was13 00032 ndash 00036 fishgallon13 Additionally no13 significant

differences in growth rate were observed between fish smaller than 210 mm TL and fish

larger than 210 mm TL when all recaptured fish were combined

We also measured the growth rate of very large fish in a lined pond On Jan13 2513 201013

156 adult fish with PIT tags were recovered from13 Pond 3 upper13 These fish were13 in the13

pond for 257 days and experienced an average13 growth13 rate13 of 024mmday or 73

mmmonth (Figure13 7)13 This growth13 rate13 is slightly13 lower13 than13 the13 average13 growth13 rate13

observed13 at Bubbling13 Ponds Hatchery in other studies (0275 mmday 825 mmmonth)

but may not be biologically meaningful We would expect larger13 fish to13 have13 reduced

growth rates according to a typical Von Bertalanfy growth model (Bertalanffy 1957) but it

appears that13 over the size range we evaluated (300 -shy‐ 450 mm TL) growth rates have not

slowed significantly compared to that of smaller13 fish grown at Bubbling Ponds13 Hatchery

Growth13 of razorback suckers13 is known13 to13 slow as13 fish reach13 larger13 sizes but it appears13 this13

reduced growth rate may not really start to be biologically meaningful at Bubbling Ponds

Hatchery13 until razorback suckers13 exceed 450 mm TL

Growth in unlined ponds

Growth13 rates13 for the13 fish recaptured13 during13 the Pond 1 lower13 thinning13 (120 days13 in

the pond) was 024 plusmn 003 mmday (729 plusmn 090 mmmonth) (Figure13 8)13 Fish13 that were13 in

the pond for nearly the entire year grew13 an13 average13 of 024 plusmn 001 mmday (726 plusmn 027

mmmonth) These growth rates are surprisingly the lowest measured growth rates for

any part of our study and differ significantly from13 every other measured growth rate

except very large13 fish (Figure13 9)13 Separating13 out13 large fish that13 were in13 the pond for the

entire year makes no difference fish that were added to the pond at TL lt300 mm grew

43

13

Gro

wth

Rat

e (m

md

ay)

020

026

032

0244 plusmn 001 mmday (733 plusmn 028 mmmonth) and and those with TL gt= 300 mm at the

start of the experiment grew 022 plusmn 003 mmday (651 plusmn 101 mmmonth)

Razorback Growth Rates in Lined Ponds

Figure 7 Growth ofrazorback suckers in(mmday plusmn standard error)in Pond 8 upper in 2008-shy‐2009 An ANOVA did notdetect any significantdifferences

7 Months Full Year 300+ mm fish

Effects of sorting on growth

One hundred and seventy five tagged razorback suckers were recovered from13 Pond

8 upper13 on March13 24 2010 (378 days13 of growth)13 These were13 the13 larger sorted13 fish (gt140

mm TL) that came out of Pond13 5 on March13 11 2009 One13 hundred and13 twenty13 two13 tagged13

razorback suckers were also recovered from13 Pond13 7 upper on March13 31 2010 (385 days13 of

growth)13 These were13 the13 smaller sorted13 fish (lt140 mm TL) that came out of Pond13 5 on

March 1113 200913 No significant differences in growth rate (mmday) were observed among

larger fish in Pond 8 and smaller fish in Pond 7 (pgt005 ANOVA) (Figure 10)13 indicating

that13 sorting may have helped to offset the original slower growth trajectory of the smaller

fish Temperatures of Ponds 7 and 8 upper remained similar throughout the year13 (Figure

5)

44

13

13

13

Gro

wth

Rat

e (m

md

ay)

Gro

wth

Rat

e (m

md

ay)

020

026

032

020

026

032

Razorback Growth in an Unlined Pond

Figure 8 Growth of razorbacksuckers (mmday plusmn standard error) in Pond 1 lower (an unlined pond)in 2010-shy‐2011 An ANOVA did notdetect any significant differences

6 Months 12 Months lt 300 mm Fish 300+ mm Fish Growth Growth

Lined vs Earthen Ponds 1 year of growth

Figure 9 Growth of razorbacksuckers (mmday plusmn standard error) in lined and unlined ponds A t-shy‐test13 did not detect a significantdifference

Lined Pond Unlined Pond 1 Yr Growth 1 Yr Growth

45

13

Effect of Sorting G

row

th R

ate

(mm

day

) G

row

th R

ate

(mm

day

)

032

020

026

032

020

026

Smaller Fish Larger Fish

Effect of Ich

Figure 10 Average growthof razorback suckers(mmday plusmn standard error)that were size-shy‐sorted intosmall fish (pond 7) and largefish (pond 8) populations At-shy‐test did not detect asignificant difference

Figure 11 Average growth ofrazorback suckers (mmday plusmnstandard error) after Ich wasremovd from the hatcheryrsquos springand after Ich was again detected inthe pond The growth rate withoutIch is significantly higher than boththe rate after Ich and the ourstudyrsquos average annual growth ratein lined ponds (ANOVA p =00003)

Growth without Ich Growth With Ich Average Annual 4 months 4 months Growth Rate

46

13

Effect of Ich on razorback sucker growth rates

Seventy-shy‐four13 tagged13 razorback suckers13 were13 recovered from13 Pond 8 on September

15 2010 These fish had13 been13 in the pond for 4 months and experienced a growth rate of

032 mmday or 97 mmmonth (Figure13 11)13 This growth13 rate13 is significantly higher (p =

005 two sample t-shy‐test) than the mean growth rate for the same group13 of tagged fish after

Ich detection (022 mmday or 65 mmmonth) and significantly higher than any other

individual growth13 rates13 observed13 to13 date13 at Bubbling13 Ponds Hatchery13 (Figure13 11)13 If this13

growth13 rate13 were13 extended throughout13 the entire13 year13 fish on average from13 Ich-shy‐free13 ponds13

would be 16 mm longer than fish from13 ponds infested with Ich Studies conducted at

Bubbling Ponds hatchery in 2008 (Ward 2008) did not reveal any effects of the treatment

chemicals on razorback sucker growth rates so it13 is likely that13 the parasite outbreaks

themselves are causing reducing growth rates rather than the chemicals used to treat the

parasites13

Conclusions

Our results suggest that under typical hatchery operations (maximizing number of

fish produced)13 the growth13 rate13 of razorback13 suckers13 is relatively13 consistent at Bubbling13

Ponds hatchery13 at 02-shy‐03 mmday (6-shy‐9 mmmonth)13 but is lower than growth13 rates13 at

other13 facilities (02 ndash 18 mmday Ward et al 2007)13 This growth13 rate13 has13 been13 constant in

both lined and unlined ponds and at all fish densities we were able to measure To achieve13

growth13 rates13 substantially higher than this will likely require13 significant changes in rearing

practices that may not be practical in order to reach numerical production13 goals

Temperature is a key variable in fish growth but seasonal growth patterns

described13 above13 (Figure13 5) demonstrate that water temperatures are high enough in

winter to maintain razorback growth Differences in water temperature by season

currently13 do not fluctuate more than 10degC at Bubbling Ponds because of the continuous

supply of water flowing through each pond (approx 225 gallonsmin) These high water

flows appear to keep pond temperatures within the thermal preference13 for razorback

suckers13 (1213 -shy‐ 28 degC Bulkley and Pimentel 1983) throughout the entire year with

temperatures rarely dropping13 below 16deg13 C (Figures 513 6)13

47

13

Fish density is another key variable in fish growth and though the number of fish in

a pond during our study ranged from13 3000 to 700013 fish we13 did not find any13 correlation13

between13 density and growth rate13 This might yield two conclusions First13 razorback

growth13 may be changed equally13 by13 densities13 at the13 hatchery13 (ie13 a density13 of 3000 fish in a

pond is as stressful13 for razorbacks as a density13 of 7000 fish) An alternative is that other

factors13 such as disease outbreaks have13 stronger13 control over fish growth13 than13 density13

Fish density13 would13 have13 to13 be13 experimentally manipulated to test13 this13 and hatchery

operations (producing the maximum13 number of fish) prevented our manipulating density13

in ponds for this13 work The trouble with manipulating density demonstrates the difficulties

associated with changing13 hatchery13 practices experimenting with density would have

prevented BPH from13 meeting13 production13 goals Given that the stocking of smaller

razorbacks has met with very little success perhaps BPH goals could be changed from13

producing 12000 fish at 300+ mm per year to a smaller number of very large fish each

year Growing13 fewer13 larger13 fish could potentially be accomplished in the same time frame

as more smaller fish but a better understanding of how density alters growth rate would

be required to be confident13 of this

The very slow growth13 in the13 earthen13 unlined13 Pond 1 lower13 was very surprising We13

had13 anticipated13 that the13 diversified diet13 cover and13 other13 habitat features13 provided by13

unlined ponds would yield dramatically increased growth rates However these traits were

not enough to offset high fish densities and in fact the unlined pond in our study13 suffered

mortality to bring densities down to that observed normally in lined ponds

Our data13 suggest13 that razorbacks13 sucker13 growth13 rates13 are13 higher in lined13 ponds13

However we13 think the reasons13 for the13 very slow growth we observed13 in the13 unlined13 pond13

in our study13 is instead13 linked13 to13 the13 usage13 of Pond 1 lower13 during13 the13 study13 rather13 than13

intrinsic13 slow growth13 in earthen13 ponds First the pond was at extremely high density for at

least part of the study The volume of Pond 1 lower has not been estimated but hatchery

managers suggest 1500-shy‐2000 fish is an appropriate number of individuals so this pond

was at a very high density for much of the experiment Second dissolved oxygen is often

very low in the13 large13 earthen13 ponds during the heat of summer much lower than that of

lined ponds This will both limit the number of fish that can survive in the pond and almost

certainly13 increases stress13 of these13 fish potentially13 reducing growth13 The DO crashes also13

48

13

limit the amount of feed hatchery managers can give fish in these ponds sometimes for

days or weeks at a time which further reduces growth during warm13 weather

Our data13 suggests that13 growth rates at the Bubbling13 Ponds Fish Hatchery are likely

as high as possible given13 the pond densities required to meet production goals and the Ich-shy‐

infested water that feeds the facility Sorting practices are successful in helping as many

fish as possible reach stocking length as fast as possible Unlined ponds may be able to

grow13 large13 fish at low13 densities13 but whatever factors allow13 for that13 growth are not13 able to

overcome high fish density The removal of invasive13 fis that act as13 a host for the13 parasite13

Ich fish from13 the Bubbling13 Ponds spring13 allowed the highest13 growth rate at 032 mmday13

(96 mmmonth) but that growth rate decreased again as Ich re-shy‐infested13 the13 hatchery13

Consistently13 achieving13 growth13 rates13 as high or substantially13 higher than13 this13 will likely13

require13 significant changes in rearing practices that may not be practical in order to13 reach13

numerical production13 goals

Two major changes that might result in higher growth rates are substantially

reducing fish density and modifying the way spring water is delivered to the facility (via

either repeated chemical treatments or enclosed concrete water diversions) to eliminate

Ich from13 the hatchery source water Other potential changes not address by our work

include13 flow-shy‐training razorbacks much previous literature including MSCP-shy‐funded13 work

on razorback suckers13 suggests13 that fish growing13 in flowing water will grow13 faster than fish

in still water (Jorgensen and Jobling 1994) Furthermore there are a wide variety of

potential benefits associated with growing13 fish13 in flowing13 water in addition13 to increased

growth13 rates13 (Davidson13 199713 Castro13 et al13 2011) Another option13 for increasing13 growth13

rates13 include13 changing to13 intensive13 culture13 in large circular13 tanks

Finally given that the stocking of smaller razorbacks has met with very little

success13 perhaps13 BPH13 goals13 could13 be13 changed from13 producing 12000 fish at 300+ mm per

year to a smaller number of very large fish each year Growing fewer larger fish could

potentially be accomplished in the same time frame as more smaller fish but a better

understanding13 of how density13 alters growth13 rate13 would13 be13 required to13 be13 confident of this

49

13

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower13 Colorado13 River Multi-shy‐Species13

Conservation Program13 (LCRMSCP) under Work Task C10 We13 thank Ty Wolters13 Tom13

Burke13 and Eric13 Volkman for their support of this research and Frank Agygos and Dave

Billingsly13 of the Bubbling13 Ponds Fish Hatchery13 for their willingness to participate in13 this

research13 and13 for their technical assistance We also thank the LCRMSCP fish group from13

Boulder City13 NV for their assistance with harvesting13 ponds and tagging13 fish13

50

13

Literature13 CitedAnders P J 1998 Conservation aquaculture and endangered species can objective science13

prevail13 over risk13 anxiety Fisheries 23(11) 28-shy‐31

Anderson R O and R M Nuemann 1996 Length weight and associated structural indicesPages 447 ndash 482 in B R Murphy13 and D13 W Willis13 editors13 Fisheries techniques13 2ndedtion American Fisheries13 Society13 Bethesda13 Maryland

Bain M B J T Finn and H E Brooks 1988 Streamflow regulation and fish communitystructure13 Ecology13 69382-shy‐392

Bays J H Zarbock R Whitman and T Murphy 2005 Conceptual design and managementof native13 fish refugia on the13 lower13 Colorado13 River In13 CL Spring13 and13 S Leoneditors Proceedings of two symposia Restoring native fish to the lower ColoradoRiver13 interactions13 of native and non-shy‐native13 fishes 13ndash1413 July13 1999 Las13 Vegas13 Nevada13 Restoring13 natural function within a modified riverine environment thelower Colorado River13 8ndash913 July13 1998 U S Fish and13 Wildlife13 Service Southwestern13 Region Albuquerque New Mexico Pages 167-shy‐177

Bertalanffy L Von 1957 Quantitative laws in metabolism13 and growth13 Q Rev Biology 32217 ndash 231

Bingham T B Scheer and C McAda 2003 Propagation facilities in Grand Valley (24 RoadHatchery Horsethief13 Ponds and13 grow-shy‐out ponds) for captive13 rearing13 ofendangered13 fishes for the13 upper13 Colorado13 River basin13 Colorado River RecoveryProgram FY2003 annual project report13 US Fish and13 Wildlife13 Service GrandJunction13 4pp

Birchell G J and K Christopherson 2004 Survival growth and recruitment of larval andjuvenile razorback13 sucker (Xyrauchen texanus) introduced13 into13 floodplain13 depressions13 of the13 Green River Utah13 Final report13 Upper13 Colorado13 RiverEndangered Fish Recovery Program13 Project No C-shy‐6RZ Publication Number 04-shy‐1513 Utah13 Division of Wildlife13 Resources Salt Lake13 City13 Utah13 67 pages

Brannon E L 1993 The perpetual oversight of hatchery programs Fishery Research 1819-shy‐27

Brett J R 1979 Environmental Factors and growth pages 599-shy‐67513 InW S Hoar13 D13 J13 Randall and J R Brett (eds) Fish Physiology Volume 8 Bioenergetics and GrowthAcademic Press New York

Brooks J E 1986 Annual reintroduction and monitoring report for razorback suckerXyrauchen texanus in the Gila River Basin Arizona 1985 US Fish and WildlifeService13 Offices of Endangered13 Species and Fishery13 Resources Albuquerque 23 pp

51

13

Brunson13 R E and K D13 Christopherson13 200513 Larval13 razorback13 sucker and bonytailsurvival and13 growth13 in the13 presence13 of nonnative13 fish in the13 Baeser13 floodplainwetland of the middle Green River Final report prepared for Upper13 Colorado RiverBasin Endangered Fish Recovery Program Project No C-shy‐6-shy‐rz-shy‐bt Publication13 No 05-shy‐26 Utah13 Division of Wildlife13 Resources13 Vernal13 32 pp

Bulkley R V and R Pimentel 1983 Temperature preference and avoidance by adultrazorback suckers Transactions of the American Fisheries Society 112601-shy‐607

Burke13 T13 199513 Rearing13 wild razorback13 sucker larvae in13 lake-shy‐side13 backwaters13 LakeMohave ArizonaNevada Proceedings of the Desert Fishes Council 2635

Busacker G P I R Adelman and E M Goolish13 199013 Growth13 Pages 363 ndash 387 in C BSchreck and p B Moyle editors Methods for fish biology American FisheriesSociety Bethesda Maryland

Castro V B Grisdale-shy‐Helland S J Helland T Kristensen S M Jorgensen J Helgrud13 GClaireaux A P Farrell A Krasnov and H Takle 2011 Aerobic training stimulatesgrowth and promotes disease resistance in Atlantic salmon (Salmo salar)Comparative Biochemistry and Physiology -shy‐ Part A Molecular amp IntegrativePhysiology13 160(2) 278-shy‐290

Czapla T E 2002 Facilities plan for the production of endangered fishes to meet statestocking13 plans13 as13 part of the13 Upper13 Colorado13 River Endangered13 Fish RecoveryProgram Upper Colorado River Basin Recovery Implementation Program US Fishand Wildlife Service13 Denver13 9 pp

Davidson W 1997 The effects13 of exercise13 training on teleost fish a review of recentliterature Comput Biochem Physiol 117A67ndash75

Figiel Jr C R 2005 Annual report fiscal year 2004 Willow Beach National13 Fish HatcheryUS Fish and Wildlife13 Service Willow Beach 17 pp

Figiel Jr C R M E Ulibarri G Carmichael J Seals and J N Hanson 2005 Intensive13 fish13 culture of warmwater native fishes at a coldwater fish hatchery Pages 164-shy‐16613 inProceedings of two symposia restoring native fish to the lower Colorado13 River13 interaction13 of native13 and13 non-shy‐native13 fishes July13 13-shy‐1413 1999 Las Vegas Nevada USFish and Wildlife Service Southwest Region Albuquerque New Mexico

Gerking13 S D 1978 Ecology of freshwater fish13 production13 Halstead Press13 New13 York

Gustafson W and Q Bradwisch 2000 Wahweap operation and maintenance -shy‐-shy‐ UtahColorado River Recovery Program FY 2000 annual project report Project No 29cUtah13 Division of Wildlife13 Resources Page AZ 3pp

52

13

Hamman R L 1985 Induced spawning of hatchery-shy‐reared13 razorback sucker ProgressivFish Culturist 47(3) 187-shy‐189

Hanson J N 1996 Annual report fiscal year 1996 Willow Beach National Fish HatcheryUS Fish and Wildlife Service13 Willow Beach 9pp

Irving D S Seversen and M Montagne 2004 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2004 annual project13 report Report No 29b US Fish and13 Wildlife13 Service Vernal 3pp

Jorgensen E H and13 M Jobling 1994 Feeding and13 growth13 of exercised13 and13 unexercised13 juvenile Atlantic salmon in freshwater and performance after transfer to seawaterAquaculture International 2 154-shy‐164

Kaeding L R and D B Osmundson 198913 Colorado13 Squawfish13 and13 razorback sucker grow-shy‐out pond studies as part of conservation measures for the green mountain andRuedi reservoir water sales Final report for agreement number 6-shy‐AA-shy‐60-shy‐00150

Koebele13 B P13 198513 Growth and the size hierarchy effect an experimental assessment ofthree proposed mechanisms activity differences disproportional food acquisition13 pysiological stress Environmental Biology of Fishes 12 181-shy‐188

Kretschmann A E and L L Leslie 2006 Razorback sucker (Xyrauchen texanus) status13 reproduction and recruitment in Senator Wash Reservoir CA Final Report13 to USBurea of Reclamation Cooperative Agreement No 00-shy‐FG-shy‐34-shy‐ 0009 p 32 ArizonaGame and Fish Department Phoenix

Marsh13 P13 C13 1987a13 Digestive tract13 contents13 of adult razorback suckers13 in Lake13 MohaveArizona-shy‐Nevada Transactions of the American Fisheries Society 116117-shy‐119

Marsh P C 1987b Native fishes at Buenos Aires National Wildlife Refuge and ArizonaState University Research Park Arizona opportunities for management researchand public13 education13 on13 endangered species13 Proceedings of the Desert13 FishesCouncil 1967-shy‐78

Marsh P C 1994 Rearing native Colorado River fishes in golf course ponds Arizona StateUniversity Tempe 22 + pages

Marsh13 P13 C13 200013 Fish population13 status and evaluation13 in13 the Cibola13 High Levee PondFinal report agreement number 99-shy‐FG-shy‐30-shy‐00051 US Bureau of ReclamationBoulder City13 Nevada13 20 pages

Marsh P C and C A Pacey 1998 Growth of wild adult razorback suckers13 in Lake13 Mohave13 Arizona-shy‐Nevada13 Final report13 US Bureau of Reclamation Boulder City Nevada 25pages + appendices

53

13

Marsh P C B R Kesner and C A Pacey 2005 Repatriation as s management strategy13 to13 conserve a critically13 imperiled fish species North American Journal of FisheriesManagement 25 547-shy‐556

Marsh P C and C A Pacey 2005 Immiscibility of native and non-shy‐native13 fishes Pages 59-shy‐63 inMJ13 Brouder13 CL13 Springer13 and CS13 Leon13 editors13 Proceedings of two13 symposia Restoring native fish to the lower Colorado River interactions of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 NV and13 Restoring natural13 function within a modified riverine environment the lower Colorado River13 July13 8-shy‐913 1998 Las Vegas NV US Fish and13 Wildlife13 Service Southwest Region AlbuquerqueNew Mexico

Marsh13 P13 C13 and J13 E Brooks13 198913 Predation13 by ictalurid catfishes as a deterrent13 toreestablishment of hatchery-shy‐reared13 razorback sucker The Southwestern Naturalist34188-shy‐195

Matthews R A 2005 Ichthyopthirus multifiliis Fouquet and Ichthyopthirosis infreshwater13 teleosts13 Pages13 159-shy‐218 in Advances in Parasitology volume 59 J RBaker R Muller D Rollinson (eds) Academic Press

McCarthy13 M S and W L Minckley 1987 Age estimation for razorback sucker (PiscesCatostomidae) from13 Lake Mohave Arizona and Nevada Journal of the Arizona-shy‐Nevada Academy of Science 2187-shy‐97

Minckley13 W L13 198313 Status of the razorback13 sucker13 Xyrauchen texanus (Abbot)13 in13 thelower Colorado River basin13 The Southwestern13 Naturalist13 28(2) 165-shy‐187

Minckley13 W L13 199113 Native fished of the Grand Canyon13 region an obituary13 Pages 124-shy‐177 in Colorado River ecology and dam13 management National Academy PressWashington13 DC

Minckley13 C13 O and M LaBarbara13 199913 Report13 on13 native fish grow-shy‐out facilities13 at Cibolaand Imperial National Wildlife Refuges 1993-shy‐199513 US Fish and13 Wildlife Service13 Parker Fishery Resources Office Parker Arizona

Modde13 T13 199613 Juvenile razorback sucker (Xyrauchen texanus) in a managed wetlandadjacent13 to the Green13 River13 Great13 Basin13 Naturalist13 56375-shy‐376

Modde T KP Burnham and E J Wick 1996 Population status of the razorback sucker13 inthe middle Green River (USA) Conservation13 biology 10 110-shy‐119

Modde13 T13 and G13 B Haines13 200513 Survival13 and growth of stocked razorback13 sucker andbonytail in multiple floodplain wetlands of the middle Green River under resetconditions13 Final report prepared for Upper Colorado13 River13 Basin RecoveryImplimentation Program US Fish and Wildlife Service Vernal 66 pp

54

13

Modde T Z H Bowen and D C Kitcheyan 2005 Spatial and temporal use of a spawning13 site in the middle Green River by wild hatchery-shy‐reared13 razorback suckers13 Transactions of the American Fisheries Society 134937-shy‐944

Mueller13 G13 199213 The native fish work13 group13 -shy‐ a multiagency endeavor to improve thestatus of the razorback sucker in Lake Mohave AZ-shy‐NV13 Proceedings of the DesertFishes Council 2369

Mueller G 1995 A program13 for maintaining the razorback sucker in Lake MohaveAmerican Fisheries Society Symposium 15127-shy‐135

Mueller13 G13 200613 Ecology of the bonytail13 and razorback13 sucker and the role of offchannelhabitats13 in their13 recovery Scientific13 investigations13 report 2006-shy‐5065 US GeologicalSurvey13 Denver

Mueller G and E Wick 1998 Testing of golf course ponds at Page Arizona for suitability13 as grow-shy‐out facility for razorback sucker using surplus fish from13 Ouray NationalFish Hatchery National Park Service US Fish and13 Wildlife13 Service and UtahDivision of Wildlife13 Resources 28 pages

Mueller13 G13 and T13 Burke13 200513 Survival13 of young13 razorback13 sucker (Xyrauchen texanus) inrelation to13 stocking rates13 (fishha)13 and13 in the presence13 or absence13 of predatorcommunities in Lake Mohave Arizona-shy‐Nevada13 Pages13 155-shy‐16313 in Proceedings of two13 symposia restoring native fish to the lower Colorado River interaction13 of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 Nevada US Fish and Wildlife13 Service Southwest Region Albuquerque New Mexico

Mueller13 G13 J13 Carpenter13 and P13 C13 Marsh13 200413 Cibola13 High Levee Pond annual report 2004US Geological Survey Fort Collins13 Science Center13 Colorado13 and Arizona StateUniversity Tempe 23 pages

Nesler T P K Christopherson J M Hudson C W McAda F Pfeifer and T E Czapla 2003An integrated stocking plan for razorback sucker bonytail and Colorado13 pikeminnow for the Upper Colorado River Endangered Fish Recovery ProgramAddendum13 to State Stocking Plans Upper Colorado River Basin Recovery13 Implementation Program 12 pp

Papoulias13 D and W13 L Minckley13 1992 Effects13 of foo availability13 on survival and growth13 of larval razorback suckers13 in ponds Transactions of the American Fisheries Society121340-shy‐355

Paukert13 C P D L Ward13 P J Sponholtz13 and K13 D Hilwig13 Effects13 of repeated hoopnetting13 on bonytail chub13 Journal of Freshwater13 Ecology13 20(4) 649-shy‐653

Pfeifer F M13 C Baker13 and M13 Montagne13 199913 Propagation13 facilities13 in the13 Grand Valley13 (24 Road13 Hatchery13 Horsethief13 Ponds and13 grow-shy‐out ponds) for captive rearing of

55

13

endangered13 fishes for the13 Upper Colorado13 River Basin13 Colorado13 River Recovery13 Program FY 99 annual project report Project No 29a13 US Fish and Wildlife Service13 Grand13 Junction13 5pp

Pfeifer F S Seversen and M Montagne 2003 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2003 annual reportProject No 29b13 US Fish and Wildlife13 Service Vernal13 4pp

Rabago-shy‐Castro J L Sanchez13 J G Perez-shy‐Castaneda R and13 Gonzalez-shy‐Gonzlez A 2006Effects of the prophylactic use of Romet-shy‐3013 and13 copper13 sulfate13 on growth13 condition13 and feeding13 indicies in13 channel13 catfish (Ictalurus punctatus) Aquaculture 253 343-shy‐349

Reinitz GL L E Orme and F N Hitzel 1979 Variations of body compositio and growth13 among strains of rainbow trout Transactions of the American Fisheries Society 108204-shy‐207

Ruppert13 J13 B P B Holden13 and P D Abate 1999 Age estimation and growth of razorbacksucker13 Xyrauchen texanus in Lake13 Mead Nevada Proceedings13 of the Desert FishesCouncil 3040

Schnoor K D and J Logan 2002 Operation and maintenance of JW Mumma nativeaquatic13 species restoration facility Colorado Colorado River Recovery Program FY2002 annual project report13 Project No 29d Colorado13 Division of Wildlife Alamosa3pp

Salisbury13 L13 1998 Factors13 affecting razorback13 sucker growth13 in Lake13 Mohave backwaters13 MS Thesis13 Unviersity13 of Nevada13 Las13 Vegas

Schooley J13 D13 and P C13 Marsh13 2007 Stocking of endangerdd13 razorback13 suckers13 in thelower Colorado River Basin13 over three decades 1974-shy‐2004 North American Journalof Fisheries Management 27 43-shy‐51

Severson S H H M Tyus and G B Haines 1992 An evaluation of feeds for raisingrazorback sucker Xyrauchen texanus Journal of Applied Aquaculture 155-shy‐65

Toney D P 1974 Observations13 on the13 propagation13 and13 rearing13 of two13 endangered species13 in a hatchery environment Proceedings of the Annual Conference of the Western13 Association of State Game and Fish Commissions 54 252-shy‐259

Tyus H M13 1998 Razorback sucker13 (Xyrauchen texanus) recovery plan13 University13 ofColorado Center for Limnology Boulder13 76 pages

Tyus H M13 and13 S H Severson 1990 Growth13 and13 survival of larval razorback suckers fedfive formulated diets The Progressive Fish Culturist 52197-shy‐200

56

13

Ulibarri M E 2003 Annual report fiscal year 2001 Dexter National Fish Hatchery13 andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 26 pages

Ulibarri M E 2003 Annual report fiscal year 2002 Dexter National Fish Hatchery andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 59 pages

USBR 2006 Lower13 Colorado13 River Multi-shy‐Species Conservation Program final fishaugmentation plan Boulder City 19 pp

USFWS 2002 Razorback sucker (Xyraouchen texanus) recovery goals Amendment andsupplement to the Razorback Sucker Recovery Plan13 US Fish and Wildlife Service13 Region 6 Denver13 Colorado

USFWS 1999 Annual report 1999 Ouray National Fish Hatchery Vernal 25pp

USFWS 2004 Management plan for the big-shy‐river13 fishes of the13 lower13 Colorado13 river basinamendment and supplement to the bonytail humpback chub Coloradopikeminnow and razorback sucker recovery plans

USFWS13 2005 Station13 profile13 of the13 Dexter13 National Fish Hatchery13 and Technology CenterUS Fish and Wildlife13 Service Dexter

Valdez R A P G Mangan R Smith and B Nilson 1982 Upper Colorado River fisheriesinvestigations13 inW H Miller J J Valentine D L Archer H M Tyus R A Valdezand L13 Kaeding13 editors13 Colorado River Fishery13 Project13 Part 2 Field13 investigations13 US Bureau of Reclamation Salt Lake City Utah

WBNFH 2004 Culture methods of the endangered razorback sucker Xyrauchen texanusUS Fish and Wildlife13 Service Willow Beach National Fish Hatchery13 8 pp

Ward D 2008 Effects of disease treatments on growth of razorback sucker ReportSubmitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 Inpartial fulfillment of work task C10 agreement number 06FG30039

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57

Appendices

Appendix 1 Survey Questions Survey of Razorback Sucker Culture in the

Southwestern United States

The enclosed survey is being distributed by the Arizona Game and Fish Department to razorback sucker culture facilities throughout

the Southwestern United States The purpose of this survey is to consolidate information regarding culture of this species so that

appropriate facility improvements can be considered for Bubbling Ponds Hatchery in Arizona Specifically we wish to increase

growth rate and production efficiency at the hatchery Information gathered in this survey will be summarized in a final report to US

Bureau of Reclamation in Boulder City NV and disseminated to all facilities that participate in the survey A workshop to discuss

the findings of this study as well as to share general information concerning razorback sucker culture will be organized by the

Arizona Game and Fish Department at the conclusion of this study and all participants will be invited

Thank you for taking the time to fill out this survey Please contact Mike Childs if you have questions or would like to discuss the

survey

Mike Childs

mchildssedonanet

(928) 639-1346

(928) 634-1279

Facility_____________________________________ Date___________________

Contact Phone _____________________________

ContactPerson_______________________________

Contact Email _______________________________

1 Water quality ranges at this culture facility

Season

Spring (Mar-May) Summer (Jun-Aug) Fall (Sept-Nov) Winter (Dec-Feb)

Temperature (C)

PH

DO (mgL)

PO4 (mgL)

TDS (mgL)

Hardness (mgL)

CaCO3

Pathogens

37

13

I Literature13 Review

Section13 SummaryThe few remaining razorback sucker populations are sustained by captive rearing and stockingprograms Captive-shy‐reared razorback suckers commonly13 experience13 high predation whenstocked into natural environments This13 creates13 the need to rear fish to larger sizes13 in captivityand to13 find new ways to13 improve growth for captive-shy‐reared fish We reviewed publishedliterature and agency reports for information on factors that affect growth of13 razorback suckerSite visits to13 razorback sucker production facilities and surveys of fish hatchery13 personnel wereconducted to obtain information on current rearing practices Razorback sucker growth is13 extremely13 variable13 and impacted by13 many13 factors including13 fish size13 and age sex densityamount of living13 space quality13 and quantity13 of food genetics and temperature This makesevaluations of individual factors that affect growth difficult Culture13 practices for razorbacksuckers13 vary widely and include differences13 in rearing environments rearing densities feedingregimes and types of feed as well as grading or13 sorting practices The focus at most razorbackrearing facilities is production so the types of data that are collected13 are often insufficient fordetailed13 evaluations of rearing practices on growth Calculated13 growth13 rates from theliterature vary widely and range from 02 ndash 1813 mmday Typically the highest growth13 rates arereported from natural or semi-shy‐natural pond environments These growth rates indicate thatjuvenile razorback suckers have a very high growth potential under ideal rearing conditionsDetailed replicated studies are needed to accurately compare the effects of individual rearingpractices on13 growth These types of studies will ultimately provide both time and cost-shy‐savings13 to production facilities by reducing the time it13 takes for razorback suckers to reach stockingsize improving overall production efficiency

8

13

Introduction

State and federal wildlife management agencies have been rearing razorback

suckers in captivity since the 1970rsquos (Toney 1974 Hamman 1985) to augment declining

natural13 populations Both wild-shy‐caught larvae13 and captive-shy‐bred fish are reared at fish

hatcheries13 and13 grow-shy‐out ponds throughout the13 southwestern13 United13 States13 (reviewed13 in

Mueller 2006) Each facility has unique environmental conditions and different rearing

methods which yield different growth rates Unlike commercial fish species which have

been cultured and studied extensively little published information is available on the

effects of various rearing methods on growth of razorback sucker

Low survival rates13 of stocked13 razorback suckers13 (Brooks13 1986 Marsh13 and13 Brooks13

1989 Marsh13 and13 Pacey13 2005)13 have13 caused13 target sizes for stocking13 to13 steadily13 increase13 in

efforts to reduce predation mortality (Marsh et al 2005 Schooley and Marsh 2007)

Rearing fish to larger sizes comes with increased costs and creates the need to know which

factors13 have the greatest impact on growth rate and how these factors can be controlled to

maximize growth This document compiles and summarizes information on current

captive13 rearing practices13 and associated13 growth13 rates13 for razorback sucker13

We reviewed relevant13 published literature and agency reports on13 razorback13 sucker

to compile background information regarding the effects of environmental factors and

rearing methods on growth A questionnaire was developed (Appendix 1) and sent to

hatchery managers who rear razorback suckers Follow up surveys13 were13 also13 conducted13

by telephone (Appendix 2) Information on rearing densities water quality diseases and

management practices at each facility were recorded Site visits to Bubbling Ponds State

Fish Hatchery13 in Arizona Dexter National Fish Hatchery in New Mexico Grand Valley

Endangered Fish13 Facility13 in Colorado13 Ouray13 National13 Fish13 Hatchery13 in Utah and the Willow

Beach National Fish Hatchery in Arizona were also conducted as part of this knowledge

assessment Telephone interviews were conducted with personnel from13 other locations

that13 produce razorback13 suckers (Uvalde National13 Fish Hatchery13 Hualapai Ponds13 Lake

Mead Fish Hatchery and JW Mumma Fish Hatchery) or facilities that formerly produced

razorback suckers but currently focus on other species (Wahweap Fish Hatchery Achii

Hanyo13 National Fish Hatchery Mora National Fish Hatchery)

9

13

Information from13 all of these sources is summarized to aid future researchers in the

design of more detailed studies on razorback sucker13 growth Understanding the13 factors13

that13 control13 razorback13 sucker growth will13 allow13 expanded fish-shy‐rearing capabilities13 and13 aid13

in reaching management objectives for stocked fish Preservation of genetic resources for

razorback suckers13 depends on captive rearing and stocking programs until permanent

solutions to factors that prevent wild recruitment can be found

Summary13 of Facilities

There are13 over 50 locations13 that have13 been13 used to13 rear13 razorback suckers13 (Table13 1) These

include13 both13 intensive13 culture13 facilities13 with13 raceways13 or circular13 tanks13 as13 well as13

production13 ponds13 golf-shy‐course13 ponds and natural floodplain-shy‐wetlands The majority of

razorback suckers that are stocked come from13 six major production facilities Bubbling

Ponds State13 Fish13 Hatchery13 The Grand13 Valley13 Endangered13 Fish Facility13 and13 Dexter13 Ouray13

Willow13 Beach13 and Uvalde National13 Fish Hatcheries13 Tables 2-shy‐313 outline13 the13 types13 of fish

holding facilities and water quality conditions that exist at each of these main production

locations A brief summary of procedures for rearing razorback suckers at each of these

facilities13 follows

These summaries are based on interviews conducted with hatchery personnel in July 2007 during site visits

This information13 is provided only to give a brief overview of razorback grow-shy‐out procedures Please verify13

accuracy13 of specific information with individual hatchery managers

10

13

Table13 1 List of locations13 that have13 been13 used to13 grow-shy‐out razorback suckers

$$amp ()amp$+ ($ampamp$+( $amp()$+ $amp()amp+(-0(12(342056( )0(-75amp8(95amp( 0$$05(lt==gt( 5amp+(amp4amp(Aamp+amp050+(12(14$6( 5amp+(amp4amp8(B$5+( B7$(lt==lt8()C0C05(lt===8(D0$05(0($(lt==E8(amp2F(0($(lt==E(

GltHI5+(342056J( K0L05(Damp$(12(342056( K0L058(D0M(0L4( N$055(lt==E( FF(-0(12(342056( D05(9$F8(B$5+( -42amp5(amp+($amp(lt==lt( OP0(0+(342056( $+05(B68(D0Q+( N-R(lt==gt( S56(Damp$(12(342056( D05(T05amp$8(N2( B7$(lt==lt8(U5Qamp(0($(lt==H8()C0C05(0($(lt==E8(0$$05(lt==gt8(N-1V-(WXXX( NQ$+0(Damp$(12(342056( NQ$+08(Y0L( N-R(lt==gt( V2M07(12(342056( M058(N2( B7$(lt==lt8(Qamp(amp+(5+M42(lt===( V$$M(042(Damp$(12(342056( 0$M(3Q05(KF(amp(B$5+(RQ058(95amp( 3ampamp(WXXgt( 942(3amp6( D05()5P058(95amp( N-1V-(lt==Z( --+-0+-12-3(4-5 )005(7amp+( 5amp+(amp4amp8(B$5+( Y2+(amp2F8(705amp$(4FFamp4amp( ltgt(5+(7amp+( 5amp+(amp4amp8(B$5+( )C0C05(0($[(WXXX( amp+(7amp+(( 5amp+(amp4amp8(B$5+( )C0C05(0($[(WXXX( B$6F05()amp+( BampC$0amp40(C(B$5+(amp+(ampampamp( )C0C05(0($[(WXXX8(B7$(lt==lt( B$5+(I(W](++amp$($00+(7amp+( 5amp+(T$$068(B$5+( )C0C05(lt===( KP0(5+(7amp+( 5amp+(T$$068(B$5+( )C0C05(0($[(WXXX( 32$amp0(7amp+( 5amp+(T$$068(B$5+( )C0C05(0($[(WXXX( 35020C(505amp(7amp+( 5amp+(amp4amp8(B$5+( )C0C05(lt===8(B7$(lt==lt( 0-6-3+ $620(Famp47$($C(450( $6208(B$C5amp( ^50amp($C(450_(9-N(R00542()5P( 08(95amp( 52(WXXH8(52(WX]( )0($C(450(7amp+( )08(95amp( 0$$05(amp+(V4P(WXX]( 768639 0amp(50(DVR( -2(C(Y4amp8(95amp( 52(WX]( B$(32(O0Q00()amp+( B$(Damp$(V$+$C0(R0C08(D05($6208(B$C5amp( 52(lt===8(amp4P$06(amp+(O55(WXXX8(0$$05(lt==gt( SQ05amp(M$+$C0(amp0F0amp(50( D05(OP0(0+(ampC$M8(D0Q+( N-R(lt==gt( -0amp5(V2( D52(C(`F8(95amp( ^5042Fampamp(amp+(O0$0(lt==gt8(amp4P$06(amp+(O55(WXXX( )1(+ KQ(4Q0( OP0(2Q08(95amp( 0$$05(WXXlt8(0$$05(amp+(5P0(lt==Z( 95amp(aQ0amp$0( OP0(2Q08(95amp( -$56(WXX]( -2(-+0Mamp+05( OP0(2Q08(95amp( -$56(WXX]( `F(BQ0( OP0(2Q08(95amp( 0$$05(WXXlt8(0$$05(amp+(5P0(lt==Z( Kamp+6( OP0(2Q08(D0Q+( -$56(WXX]( D52(B20F020Q0( OP0(2Q08(D0Q+( -$56(WXX]( D52(X($0( OP0(2Q08(D0Q+( Y6(V$05(N-R8(705amp$(4FFamp4amp( V$$M( OP0(2Q08(D0Q+( Y6(V$05(N-R8(705amp$(4FFamp4amp( D0Q+(A( OP0(2Q08(D0Q+( Y6(V$05(N-R8(705amp$(4FFamp4amp( D0Q+(O5Q0( OP0(2Q08(D0Q+( Y6(V$05(N-R8(705amp$(4FFamp4amp( 0+58lt+--457(5 9Q0(50ampampamp( D05(T05amp$8(N2( )C0C05(0($[(lt==E( ampamp(5+0( D05(T05amp$8(N2( )C0C05(0($[(lt==E( 2ampamp(F( D05(T05amp$8(N2( ++0(amp+(3amp0(lt==Z( O0(W=( D05(T05amp$8(N2( N-1V-(WXXX( O0(F( D05(T05amp$8(N2( ++0(amp+(3amp0(lt==Z( S$+(425$06(V2( D05(T05amp$8(N2( ++0(amp+(3amp0(lt==Z8(++0(WXXgt( O00+(7amp+(amp(20(Namp2(amp( D05(T05amp$8(N2( U5Qamp(0($(lt==H8()C0C05(0($(lt==E( =($+ 1$6+(OF(0(75P(GY0$0(75ampJ( O(T08(D0Q+ (52(WXXH( Y5amp++(-0(amp5(B$$00( 9$F8(B$5+( -42amp5(amp+(Oamp(lt==lt( 5MI(7amp+( D05(15Fampamp8(D( -42amp5(amp+(Oamp(lt==lt(

11

13

Table 2 Facilities available at major razorback sucker fish hatcheries

$amp( )$+(-+( 0(1(2$amp3amp(( 4-56+ amp7(8-+1$(9+( lt3-5( 8=$33( 23gt(805(

$amp()amp+(-(012345( 0(0+amp(A(BBCC(05 ampD(ED F CGBH IACCCACCC BJH K$+L(0D

amp$+(M$gt$ O-$+(+($P

B N B

CGBH IACCCACCC BABHC FANCC

BJH

Qamp+-3$+($P F FHC 637134(801amp0$(-(012345( H(L$33gt($O-amp1+(gt33A(

BCCC(05 ampDRK$+L(0D amp$+(M$gt$ M$-3$+($P Qamp+-3$+($P Qamp+-3$+($P

9O-$+amp$

SF S BC SC HC TC

CGI((IGC( HAHCC HSC IBC BCC IC

9O-$+amp$ BC SC 940amp+(amp21amp(8013(-(-02$15( U-ampamp0$3(D+ampPamp(gt$+ Qamp+-3$+($P IS VCC IB

W+Lamp1(+$+amp(0D( E-50D(+ampX+(gt$+( Qamp+-3$+($P JT BCC H K$+L(ED T CGBH(Y(CGH(

lt405(801amp0$(-(012345( J(L$33gt(gt33A(FCC(05( ampD(0D BS CGIBH(Z(CGBH( IC Qamp+-3$+($P NC IBC H Qamp+-3$+($P BJ VCC IC((IH

=$$gt(302(801amp0$(-(012345( 3$+(L$D(Q3+$D( MampX+(gt$+( amp$+(M$gt$ N IAHCC

amp$+(M$gt$ IF IFACCC 9O-$+amp$ FC IC

0$+3(801amp0$(-(012345( B([0(9O-amp1+()33A( IHCC(05 ampD(0D II I

K$+L(0D amp$+(M$gt$ amp$+(M$gt$

NJ B IB

GBH(Y(IGC( FAHCC IACCC

Qamp+-3$+($P Qamp+-3$+($P

IB N

BCC NACCC

12

13

Table13 3 Water13 quality13 ranges13 at each13 culture facility$amp ($)$++) -+$

-)amp012$)32$45 -6+)01763865 9$01-+3lt5 =amp+)01gt+39+5 $amp()amp+ ++)$6)+01A5

J gtLNL01O5 8P$ampamp401O5 ($Q+

BC3DE DD3DF BG3DB KLM3MLE KLH3MLI KLH3MLF CLM3BFLE CLM3BFLE CLM3BFLE

RQS0Aamp$ RQS0Aamp$ RQS0Aamp$ )ampQTamp$ )ampQTamp$ )ampQTamp$

8+)$O(6+T$ 8+)$ 8+)$ A6$)amp A6$)amp A6$)amp

BH3BI KLH3MLE CLM3BFLE

RQS0Aamp$ )ampQTamp$ 8+)$ A6$)amp

-01 ++)$6)+01A5 J gtLNL01O5 8P$ampamp401O5 ($Q+

BK3DE DD3DM BK3DE KLC3MLC KLC MLC DLM3GLK DLM3GLK DLM3GLK BIC3BMM BIC3BMM BIC3BMM

2ampamp$03040UQ$0amp0)6Q0amp0UampQ0ampamp0VampQ

BE3BI KLC

DLM3GLK BIC3BMM

213amp+(4amp50amp ++)$6)+01A5 J gtLNL01O5 8P$ampamp401O5 ($Q+

DH3DC DH3DC DH3DC KLK3MLE KLK3MLE KLK3MLE KLE3KLC ILC3KLE ILE3ILC BEE BEE BEE

+0$0amp+amplt+066)+0V$ampamp4S0RQ0$0)TP0T

DH3DC KLK3MLE FLC3ILC BEE

6137 ++)$6)+01A5 J gtLNL01O5 8P$ampamp401O5 ($Q+

BB3DC BB3DC BB3DC KLF3MLD KLF3MLD KLF3MLD CLE3BD CLE3KLD CLE3KLD BBG BBG BBG Aamp$ Aamp$ Aamp$

BB3DC KLF3MLD CLE3KLD BBG Aamp$

8$$9(35 ++)$6)+01A5 J gtLNL01O5 8P$ampamp401O5 ($Q+

BK3DE DE3DC BK3DE KLC3MLE KLC3MLE KLC3MLE HLE3GLE HLE3ILE HLE3GLE HEE3FEE HEE3FEE HEE3FEE RQS0Aamp$ RQS0Aamp$ RQS0Aamp$ A6$)amp A6$)amp A6$)amp 8+)$ 8+)$ 8+)$

BH3BM KLC3MLE FLE3GLE HEE3FEE RQS0Aamp$ A6$)amp 8+)$

lt3$+ ++)$6)+01A5 J gtLNL01O5 8P$ampamp401O5 ($Q+

BG3DI DI3DM BM3DM KLK3MLD KLK3MLD KLK3MLD FLE3BDLE FLE3BDLE FLE3BDLE DDI DDI DDI

A6$)amp

BF3BM KLK3MLD FLE3BDLE DDI

Bubbling Ponds State13 fish Hatchery13

Bubbling Ponds Fish Hatchery in Arizona does not maintain razorback sucker

broodstock on site Razorback suckers are received either as juveniles from13 Willow Beach

National Fish Hatchery13 or as13 newly-shy‐hatched larvae from13 Dexter13 National Fish Hatchery

Larval fish are13 typically13 placed13 into13 an unfertilized unlined 0613 acre13 pond13 in the13 spring In

September the pond is harvested by draining the pond and seining All fish that have

reached the target size (300 mm TL) are stocked Fish that are too small to stock are split

up equally between the six remaining grow-shy‐out pond at an13 average13 density13 of about 5000

ndash 7000 fish per pond Fish are fed by hand at approximately 25 body weight split

between morning and evening feedings Fish are either fed a catfish diet made by Rangenreg

13

13

that is enriched with spirulina and krill or razorback sucker diet made by Silvercupreg

depending on availability Fish are monitored visually and by sampling using a cast net

When a large number13 of fish have13 grown to13 the13 target size they13 are13 harvested13 by13 draining

the pond and seining13 Fish are again13 sorted by hand and the largest13 fish are stocked13 Fish

that13 have not13 reached the target13 size are returned to the ponds for further grow-shy‐out13 On13

average it13 takes one to two years for fish to reach the target13 size with fish growing13 an

average of 06 mmday Target numbers for production are 12000 razorback suckers

annually (300 mm TL) The biggest difficulty in rearing razorback suckers at Bubbling

Ponds13 Fish Hatchery13 is protozoan13 parasite13 infestations13 (Ich) and13 associated13 bacterial

infections that come from13 an open spring source that is inhabited by mosquitofish

Dexter National Fish Hatchery13

Dexter National Fish Hatchery maintains four separate razorback sucker13

broodstocks13 These fish are spawned on13 site and larval13 fish are placed directly into 01 acre

ponds at a density13 of about 20000 larvae13 per pond (50 ndash 100 thousand13 per13 acre)13 Ponds

are fertilized with alfalfa13 pellets and superphosphate two weeks prior to receiving13 larvae to

produce13 natural13 feed for larval13 fish13 Ponds are13 fertilized again with alfalfa13 pellets one week

after larvae are introduced13 Fish are fed a catfish starter diet13 (sizes 1-shy‐3) made by Rangenreg

that13 is enhanced with spirulina13 and krill13 and then switched over to the razorback13 diet13 once

they are large enough to eat 1mm13 crumble Fish are fed twice a day by hand four days a

week13 at 25-shy‐60 body weight Feed ration is decreased if excess feed is seen remaining

on the13 pond bottom13 following feedings Fish are not graded or sorted during this grow-shy‐out

period Razorback suckers are harvested in the fall by draining ponds completely Fish are

sorted13 at harvest and13 distributed13 to13 other13 facilities13 for further13 grow-shy‐out depending on13

current size requirements Razorback suckers are on average 100 ndash 200 mm TL after the

first growing13 season13 and13 generally13 take13 1 -shy‐18 months for a majority of the fish to reach

300 mm TL There are 16 different species of fish maintained at Dexter National13 Fish13

Hatchery13 and13 having sufficient pond13 space13 to13 grow out separate13 groups13 of fish is the13

limiting factor for production of razorback suckers at this location

14

13

Grand Valley13 Native13 Fish Facility13

The Grand Valley Native Fish Facility maintains its own brood stock13 in13 eight13 ponds

located at the Horsethief Basin Wildlife Area in Grand Junction Colorado Fish are

spawned13 on site13 and13 larvae13 are13 reared13 indoors in fiberglass13 tanks13 at the13 24-shy‐Road13 Fish13

Hatchery13 in Grand13 Junction The 24-shy‐Road13 Hatchery13 consists of two13 separate13 recirculating13

systems that operate using de-shy‐chlorinated13 city13 water13 and two13 large13 fluidized-shy‐ bed sand

filters13 and13 rotating-shy‐drum13 filters for waste removal Fish are held in 4-shy‐foot (n=78) or 8-shy‐foot

(n=14) diameter fiberglass tanks Larval fish are started on prepared feeds immediately

after swim-shy‐up and fed exclusively razorback feeds made by Silvercupreg Fish are started on

a 0-shy‐250 micron razorback diet for the first 10-shy‐1213 days13 and13 then13 fed with13 gradually13

increasing13 feed sizes based13 on observations of feeding13 (250 ndash 400 micron 1 starter) Feed

sizes are mixed when transitioning to the next larger feed size These razorback diets are

specially sifted by Dr Rick Barrows (USDA13 Hagerman experiment station Idaho)

Razorbacks13 are13 typically eating 1mm13 extruded pellets by the time they are 35 to 4 inches

in length Fish are fed approximately 70 body weight per day initially and then gradually

reduced to 15 body weight by the time they reach the 300 mm TL target size Fish are

fed seven days13 a week using13 12-shy‐hr13 belt feeders It takes13 12-shy‐16 months to grow fish to the

target13 size in13 the hatchery13

Razorback suckers are sorted after three months and culled to about 4000 fish per

family lot Culled fish are stocked into leased grow-shy‐out ponds Stocking densities for

juveniles in these ponds is based on previous13 stocking and harvest13 rates13 and is pond

specific13 Grow-shy‐out ponds are13 harvested13 periodically13 using Fyke13 nets13 or trap13 nets13 and13 fish of

the target size are stocked Disease problems (Ich Lernea) water quality problems (low

DO) and difficulty in removing all of the fish are challenges for grow-shy‐out of razorback

suckers13 in these13 natural ponds13

Fish reared13 in the13 24-shy‐Road facility are sorted again at four to five months of age into

small and large size groups to obtain more uniform13 growth rates Batch estimates of fish

weight are done every month for each tank A group of fish are weighed and counted to

give an average weight for the tank with lengths estimated based on a lengthweight chart13

The biggest difficulties13 for growing13 out razorback suckers13 at the13 24-shy‐Road13 Fish13 Hatchery13 are13

insufficient space and water flow (oxygen) to grow fish to the target size At the Horsethief

15

13

Basin13 Ponds where broodstock13 are reared13 diseases such as Ich are problematic because

water is pumped directly from13 the Colorado River

Ouray13 National Fish Hatchery13

Ouray13 National13 Fish Hatchery maintains its own broodstock and13 spawns13 fish on-shy‐site13

Larvae are transferred from13 indoor hatching tanks to unfertilized 02 acre outdoor ponds

and stocked at densities 10000 ndash 20000 larvae13 per13 pond13 Even13 though13 outdoor13 ponds13 are13

covered with13 bird13 netting13 avian predators13 still get caught in the13 nets13 if they13 can see fish

Ponds are dyed blue13 as the13 fish grow to13 prevent avian predation13 While in the outdoor

ponds13 fish13 are13 fed a slow-shy‐sinking salmon diet made by Silvercupreg twice daily by hand

Amount of feed is based on periodic sample counts Fish are grown until late September at

which time temperatures require that all fish13 other13 than13 adult broodstock13 be13 brought

inside for the winter Ponds are drained completely and fish are sorted by hand Fish that

have reached the target size (300 mm TL) are stocked into the Green and Colorado Rivers

All remaining fish are moved indoors13 and13 held13 in three-shy‐foot (n= 30) or eight-shy‐foot (n=27)

diameter circular tanks On average it takes 12 ndash 18 months to grow fish to the 300 mm TL

at Ouray13 hatchery13

Razorback suckers are held during the winter in a recirculating system13 that

operates13 using13 two13 large13 fluidized-shy‐bed sand filters and a rotating-shy‐drum13 filter for solids

removal Fish are fed the Silvercupreg razorback diet using belt feeders There is currently

capacity13 to13 hold13 only13 20000 200-shy‐300 mm TL fish inside the facility and any extra fish13 are13

stocked13 into13 floodplain-shy‐wetlands or used for research purposes13 Ouray no longer leases

any private grow-shy‐out ponds Grow-shy‐out ponds were troublesome due to poor water quality

harvesting13 difficulties13 and13 non-shy‐native13 fish introductions13 The biggest difficulty13 for

production13 of razorback13 suckers at the Ouray13 National13 Fish13 Hatchery13 is space13 during13 the

winter to maintain large numbers of fish and high iron and manganese in the well water

that must be filtered out prior to use

16

13

Willow Beach National Fish Hatchery13

Willow13 Beach National13 Fish Hatchery receives wild-shy‐caught larvae from13 Lake

Mohave Larvae are treated for diseases with formalin and malachite green and placed in

45 ten-shy‐gallon13 flow-shy‐through aquaria13 Recirculated13 solar heated water13 22-shy‐25deg C is used to13

allow production of warm13 water fish at this traditionally cold water facility (Figiel 2003

Figiel et al 2005) Fish are fed brine shrimp nauplii to satiation every hour and after 14

days small amounts of specialized larval fish diet (Encapsulon13 Cyclopeeze13 spirulina13 and

artificial plankton) are introduced After 30-shy‐6013 days13 fish are13 transferred13 to13 six13 32-shy‐gallon13

fiberglass troughs at densities of 1000 to 1500 fish per tank and then a month later moved

outside13 to13 eight recirculating13 raceways that use a combination of well water and solar-shy‐

heated water to maintain temperatures of 22 ndash 25deg C during the summer months

When13 in13 the outside raceways13 fish are fed the razorback13 diet13 using13 belt13 feeders and

fed by13 hand13 at 10 -shy‐ 70 body13 weight per13 day Feed amount is adjusted based on sample

counts according to a feed conversion program13 developed for razorback suckers by Willow

Beach Hatchery personnel This program13 uses length and number-shy‐per-shy‐pound generated

from13 several years of razorback growth data (Figure13 1) Fish are13 sorted13 opportunistically13

and are not handled during the summer months when water temperatures are above 20degC

In 2004 the target size for stocking was 325 mm TL or greater (WBNFH 2004) with a

target13 of producing13 6000 fish per year Reaching this13 target size usually13 takes13 two13 growing13

seasons13 The biggest difficulty13 in rearing13 razorback suckers13 at Willow Beach13 National Fish

Hatchery13 is insufficient space13 to13 grow fish to13 increased13 target sizes (400-shy‐500 mm TL)

Uvalde13 National Fish Hatchery13

Uvalde13 National Fish Hatchery13 in Texas13 receives 35000 ndash 60000 razorback sucker13

fry annually in MarchApril from13 Dexter National Fish Hatchery The fry are acclimated in

bags submerged in the pond for a minimum13 of one hour and released into13 a 1 acre13 fertilized13

pond where they are reared for the remainder of the summer Fingerlings are fed a starter

razorback diet when they reach approximately 50 mm TL In AprilMay the previous year

class of razorbacks are captured from13 their over-shy‐wintering pond enumerated graded and

split into13 one-shy‐acre grow-shy‐out ponds Approximately 4000 ndash 5000 fish will be13 placed13 in each13

one acre pond for summer grow-shy‐out Fish are reared for approximately 150 days (May ndash

17

13

Oct) and fed the Bozeman razorback diet two times a day five days a week at 15 ndash 30

body weight per day based on average water temperature

Figure 1 Relationship between length and number of fish per pound

In general13 juvenile razorback13 suckers (received as fry13 during13 the previous spring)13

reach the target size of 300 mm TL in approximately 6 months In 20062007 Uvalde

produced 6000 razorback suckers 300 mm TL for introduction into the San Juan River

Starting13 in 2008 Uvalde NFH will be producing13 and distributing13 12000-shy‐ 300 mm TL

razorbacks for stocking into the San Juan River Predation from13 migrating cormorants has

occurred but timing of harvest and over wintering protection methods such as covering

ponds with netting or placing fish indoors helps to minimize losses during the cormorant

migration (November to March) Uvalde has experienced razorback mortalities because of

bacterial problems but these are usually resolved through the use of oxytetracyline

medicated feed

Overview13 of Differences in Culture Methods

Several differences were noted when conducting surveys at each of the five main

production facilities for razorback sucker (See Appendix 3) These differences include

different stocking13 and13 rearing13 densities13 (Table13 4-shy‐5) various feeding regimes and type of

18

13

lt=amp

feeds (Table 7) as well as differences in grading or sorting practices Some of these

differences are13 related13 to13 whether13 or not razorback suckers13 are13 being13 reared13 in extensive-shy‐

culture13 facilities13 (ponds) or intensive-shy‐culture13 settings13 (raceways13 o tanks)13 Some13 practices13

are unique to a single facility13 or a couple of facilities (Table 6)13 Managers at each facility13

were asked to identify the biggest13 difficulty or constraint13 that13 they experience when13

growing-shy‐out juvenile13 razorback suckers13 at their13 respective13 location13 Space constraints13

water quality and disease problems were the main factors limiting production of razorback

suckers13 at these13 facilities13 (Table13 8) Calculated or reported growth rates from13 the literature

vary widely (Table 9) and range from13 02 to 18 mmday These growth rates indicate that

juvenile razorback suckers have a very high growth potential under optimal rearing

conditions13

Table13 4 Stocking13 densities13 for larvae13 and13 fry in ponds

$amp( )(+amp-( 01-2(3(4amp56( 4amp56(+amp-( 01-2782-( $amp () + --amp +amp0amp)+amp 12-3amp ( )+amp0amp+amp --amp +amp0amp)+amp 42556789amp8 ( +amp0ampgt+amp 3amp +amp0amp+amp A-BC-Damp (E + 3amp )+ F-6ltamp ) G+ 3amp G+

Table13 5 Rearing13 densities13 at intensive13 culture13 facilities13

$amp( )amp+(($-( $0( 12(3$+( 40((amp05( 67((amp05( 8$9(407$( $amp amp())amp++-$amp 0 1 0amp2amp1amp 3amp2amp4 0544

6amp())amp++-$amp 610 021 4amp2amp47amp 3amp2amp77amp 058 9$amplt+)amp 4amp())amp++-$amp 00 1 7amp2amp77amp 851amp2amp0amp 05

6amp())amp++-$amp 610 77amp2amp1amp 0amp2amp1amp 053

19

13

Table13 6 Rearing13 practices13 that are13 unique to13 specific rearing13 facilities13 $$amp( )$+-(amp$-(0(1-amp2034( $amp()amp+( -0$(12(33+(amp(amp134$53+(amp$amp3+(6amp+(

723(843(1$8(422(6amp+(42amp(4(423(19$43( 343( lt34$53(6amp+(6(4($03(amp4+94amp(842($1$1(63$$34(amp+(63626243( =amp+(gtamp94ampA( B3(1(1$+53+C3+(amp+(1$43(1(3D0$(1(amp443(amp+(amp443( 734231(amp( B3(1(193(44(1(34amp(amp(+49E(6amp+( -E3(F3+( G3amp(1(12(amp(H3(13$(4ampE(C(IJK($$amp( A( L43(+A3(4(6303amp4(63+4ampM(66$3D3amp4$(34amp(amp(6amp+(C((4amp3( L$$8(392(

B0$+3(

N43D(13+(4($0$(12M(amp+(639$53+($0$(12(+34( G3amp(12(amp(399$4amp(4+(938A(842($(2343+(843( N443D643+(3amp(12(amp(amp34(63amp(amp(423(O$+(G03( )amp+(3(134$53+(6(4(39364(1(1A(4(44(423D(amp((D3(amp4$(+34(

Table13 7 Types of feed used at razorback sucker13 hatcheries13 $amp ()amp+-amp0- $$)1amp23 45-amp)-$5)1amp23 $amp()amp+( -amp$amp+(amp+( -amp012$3+(amp+4(amp5215$(0+( 65ampamp7(85209(+2($1(87((15315lt=(+2(

+amp+amp(amp(55$5$2gt( 21( Aamp+(amp+( )amp+(012$3+(B29(5$05$95($$2(5amp+(

199524(amp5215$(0+( 65ampamp7(85209(+2($1(87(15315lt=(+2(amplt( 29gt(51($51(amp9(2(25=(C(DD(0+(

E15amp+(Famplt2amp( G1$5(lt1lt$51(25amp=( HIJKH(Dlt1amp(15315lt=(+2(I(C2(CH(+5gt( )11$gt($511(02+(15315lt=(+2(

$1(87(15315lt=(+2(D5$$(3(lt5$$gt(02+(gt( 6lt=(511B(

L15gt( G1$5(lt1lt$51(25amp=(Aamp+( amp+(

HIJKH(Dlt1amp(15315lt=(+2(I(C2(CH(+5gt( )11$gt($511(02+(15315lt=(+2(

$1(87(15315lt=(+2($1(87($B(amp=amp( 5$Damp(+2(

M$$B(5lt9(-5$+( NO515(G1$5(219( L2+1(15ltB5gt(Aamp+(5amp+( amp$amp+(amp+(

1amp(91D(amp5$(Pamplt5$amp4( 8gtlt$34(1$amp54(5amp+(5120lt5$( $5amp=2amp()amp+(012$3+(B29(5$05$95( $$2(5amp+(19952Q(amp12152( 1+lt2amp(

$1(87(15315lt=(+2($1(87(15315lt=(+2( $1(87(15315lt=(+2(

Table 8 Factors limiting production at major razorback sucker facilities

$amp( )amp+(-0+1((2$(0amp1ampamp(-34amp( $amp()amp+( -(01$2(34+(546(amp(0amp(01amp(541(13( -741( 803(3amp41amp4(9((+ltlt1amp4(03(amp(44amp(2=(4(

+ltlt3$4(4(2amp4amp(014(1gt13=(43=( 1amp+(amp34amp( 803(3amp41amp4(1$4+(4(541(A$4B(amp+(+$C+(

7Bamp($244amp(lt(1313$4amp(B42( D1B( E41(A$4B(01$2(3+(B(66(1amp(amp+(2ampamp(

Eamp41(420141(464(1A1($$(lt6(4((2C+(amp+1( 803(3amp41amp4(1$4+(4(541(A$4B(amp+(+$C+(7Bamp(

E$$5(36( 803(3amp41amp4F(15amp(lt6(4(amp31amp$B($11(gt( 1$4(amp(ampltlt3amp4(03(amp(44amp(lt1(amp5(lt6(

GC$+( 8221(420(3amp(4(6691A1amp(051((4(410$(+(4( 661(1amp+541(020amp(4(=0(0amp+(3$F(

20

13

$amp(

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S-amp(C-ampD

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gtS1

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+

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gt-(amp(

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23=J

lt(6(

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-(=22

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L+amp-(B81(b

K5(gt

gtc((8D((KKK

(S ((

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(R(6(

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(gtgt(amp(F=((Samp

D(ampD(1+8D(eQ22

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Table9Reportedandcalculatedgrowthratesfromtheliterature

Calculatedgrow

thratesbasedon

informationprovidedinliterature

aApproximationsofmaximum

grow

thpotential(basedon

average13 maximum

sizesiffishreportedatharvest

21

13

General Information on Factors that Affect Fish Growth

Growth in fish is extremely variable and is impacted by many different

physiological and environmental factors Growth rates are known to change with size and

age sex season activity level density amount13 of living space quality and quantity of food

genetics and temperature (Brett 1979) Growth experiments conducted at different times

of year can result in growth rates that are not comparable As fish become larger their

physiological13 potential to grow decreases making determination of growth rate dependent

on the size of the starting fish and the length of the experiment (Busacker et al 1990)

Genetic factors also have great potential to influence growth rate Some species have

strains13 and13 races13 that display vastly different growth potentials (Reinitz et al 1979) All of

these factors combine to make assessment of the individual factors controlling fish growth

difficult13

Water temperature is probably the most important variable affecting growth rate13

All of the basic functions that affect growth such as feeding digestion and metabolism are

temperature-shy‐dependent13 Growth13 is inseparably13 tied13 to13 bioenergetics13 and13 therefore13 also13

tightly tied to temperature When temperatures are below optimum daily temperature

fluctuations can stimulate growth Photoperiod is also commonly linked to water

temperature and can influence growth rates in fish (reviewed in Brett 1979)

Fish density13 is known to13 affect growth13 and13 can alter13 growth13 rates13 in several ways13

Fish that exhibit strong territorial behaviors13 or natural schooling tendencies13 will

experience reduced growth if densities are too high or too low (Brett 1979) Dominance

hierarchies where some fish feed more aggressively than others can also lead to high

variability13 in growth13 rates13 (Koebele13 1985) Crowded13 conditions13 also13 cause physical

interference13 between13 fish and13 poor water13 quality13 which13 reduces13 growth13 (Busacker13 et al13

1990) The effects of fish numbers space and feeding opportunity are frequently correlated13

and often13 difficult13 to distinguish (Brett13 1979)13

It is impossible to study the effects of environmental factors on growth without also

evaluating feed rations (Brett 1979) Amount of food quality of the diet particle size

number of feedings per day and time of feeding have all been shown to affect growth

(Busacker et al 1990) In controlled laboratory studies food is usually fed ad libitum13

22

13

(constantly available) and other variables are altered to assess impacts of environmental

factors13 on growth13 These studies13 are13 usually13 conducted13 in tanks13 or raceways13 because13

researchers must verify that food is constantly available to the fish which is difficult to do

in large pond environments where the fish and the bottom13 are often not visible (Busacker13

et al13 1990)

Specific Information13 o Razorback13 Sucker13 Growth

Variable13 growth

Growth in razorback suckers is naturally highly variable and may be a function of

their evolutionary history (USFWS13 2002)13 Minckley (1983) speculated that13 wide size

variation in a single cohort of razorback suckers may be adaptive with fast-shy‐growing13 fish

that13 reproduce at a young13 age surviving13 better in13 high discharge years and slow-shy‐growing13

smaller fish surviving better during drought periods This highly variable growth rate

makes rearing razorback suckers in a production setting difficult because fish from13 a single

cohort do not reach the target stocking size simultaneously One of the major tasks for

aquaculture is to maximize both individual growth and total production13 (Gerking13 1978)13

This becomes more difficult when the species being cultured exhibits highly variable

growth13 rates13 because of genetic influences as is the case with razorback13 suckers13

Razorback13 sucker growth13 is typically very13 rapid13 during13 the first13 year of life13 and then13

declines with age First year growth can be as low as 50 mm and as high as 350 mm (Valdez

et al13 1982 Minckley13 1983 Mueller13 1995) Razorback sucker13 grow rapidly13 for

approximately the first five or six years of life and then growth slows13 (McCarthy13 and13

Minckely 198713 Tyus 199813 Minckley et13 al 1991)13 Growth of older individuals in13 extant13 wild

populations is very13 low (Minckley 198313 Tyus 198813 Modde13 et al 1996)13 Wild growth13 rates

for mature adult fish in Lake Mohave based on PIT tag recaptures were often too small to

be accurately measured for both males and females over the time period of 1987-shy‐199713

(Marsh and Pacey 1998) This information suggest it will take substantially longer to rear

fish to13 increasingly13 larger13 stocking13 sizes (40013 ndash 500 mm TL) than it did to reach the target

size of 300 mm TL

Growth in ponds

23

13

One of the main strategies for maintaining genetic refugia and self-shy‐sustaining13

populations of razorback13 sucker in the lower Colorado13 River basin13 is to rear razorback13

sucker13 larvae13 in production13 ponds until they13 are13 a suitable13 size for stocking13 (USFWS13 2004)

Pond culture has proven useful to promote rapid growth of juvenile razorback suckers

(Kaeding and Osmundson 1989) Marsh (1994) reported that growth rates of razorback

suckers13 reared13 in golf-shy‐course13 ponds exceeded13 the13 best growth13 rates13 obtained13 under

intensive13 culture13 conditions13 at federal hatcheries13 especially13 during the13 first several years13

of life Growth rates in these semi-shy‐natural ponds are also comparable to estimated growth

rates13 of juvenile13 wild13 fish (McCarthy13 and13 Minckley13 1987) Modde13 and13 Haines13 (2005)

reported13 the13 greatest growth13 rates13 in the13 largest and13 deepest floodplains13 with13 the13 greatest

amount of submergent vegetation but excellent growth and survival of fish in a grow-shy‐out

pond is of little value if there is not an efficient way to collect the fish from13 the pond

(Kaeding and Osmundson 1989)

Temperature13

Bulkley and Pimentel (1983) used shuttle boxes in the laboratory to determine a

temperature preference13 for razorback suckers13 of 23-shy‐24degC13 In13 their13 studies13 razorback

suckers were found to avoid temperatures below 118 degC or above 286 degC Razorback

suckers at Bubbling Ponds Hatchery are more active in the spring and feed better as

photoperiod increases even prior to water temperatures rising (Frank Agygos personal

communication) Table 3 briefly summarizes water temperature data from13 each facility

Detailed seasonal water temperature profiles are not currently available for many

razorback grow-shy‐out sites13

Density13

Extensive studies have been conducted on commercially important species to

evaluate stocking densities and feeding rates that maximize production For these species

controlled experiments under laboratory conditions have established relationships

between temperature density and feed ration on growth (Brett 1979) but this information

is sporadic13 or non-shy‐existent for razorback suckers13 (Bays13 et al13 2005) Fish culturists13 with13

24

13

experience13 rearing13 razorback suckers13 typically13 have13 target stocking13 densities13 that13 they use

(Tables13 4 -shy‐ 5) These stocking densities have largely been determined over time by trial

and error These approximate stocking densities provide a good starting point for more

controlled13 types13 of replicated13 pond studies13

Feed ration

Razorback13 suckers are currently13 being13 fed a wide variety13 of prepared diets (Table 7)

that range from13 a slow-shy‐sinking salmon feed manufactured by Silver Cupreg to a spirulina

and krill-shy‐enhanced catfish feed made by Rangenreg Most locations are feeding 20 ndash 50

body13 weight per13 day13 Methods13 for culture13 of razorback sucker13 larvae13 in intensive13 settings13 at

fish hatcheries are well documented (Figiel 2005) and various larval fish diets have been

evaluated13 (Tyus and13 Severson 1990 Severson et al13 1992) but no standardized13 procedures

are used for feeding13 larval13 fish in13 intensive settings13

Razorback sucker larvae are also effectively reared in pond environments using

natural foods supplemented with larval fish diets and survival is high when no predators

are present13 (Mueller 2006)13 Growth rates for larval13 and early juvenile razorback13 suckers

may increase with pond fertilization Diet and physiological studies on wild razorback

suckers indicate that they feed on plankton as well as benthic organisms during their entire

life (Marsh 1987) Artificially fertilizing ponds may greatly increase production capacity

and growth rates for razorback13 sucker (Papoulias and Minckley13 1992) and warrants

further13 investigation13

Handling stress

Handling stress13 has13 been shown to13 influence growth13 rates13 Paukert13 et al (2005)

found that growth of bonytail chub was reduced by 26when compared with controls

after being13 repeatedly13 captured and handled in13 hoop13 nets13 Handling13 effects are likely13 to be

similar for razorback suckers that are repeatedly13 captured and sorted in13 a hatchery13 setting13

Razorback suckers that are handled at Willow Beach National Fish Hatchery will commonly

not eat for two weeks after handling (John Scott personal communication) This creates a

difficult situation13 for production13 facilities because13 fish13 need to be sorted to ensure13 large13

25

13

aggressive fish do not interfere with growth of smaller individuals but frequent handling

and sorting13 causes stress related reductions in13 growth13

Measuring Growth in Captive Fish

Weight is the traditional measure used to estimate growth or production in

aquaculture settings13 Groups of fish are typically13 weighed and an average individual13 weight13

is computed (Busacker et al 1990) Although this method is often logistically the easiest it

may not be the most informative for species with highly variable growth rates like

razorback suckers especially when target lengths must be reached before fish can be

stocked Weight can also be highly influenced by things like stomach fullness or

development of gonads (Busacker et al 1990) Condition factor or relative weight can also

be used to assess growth of fish but these tools may be more robust predictors of fecundity

than of growth (Anderson and Neuman 1996) For some species sexes need to be

distinguished because males and females may differ in morphology (Anderson and

Neumann 1996) Mueller (2006) analyzed growth rates based on PIT tag recaptures of 86

razorback suckers13 in High13 Levee Pond13 and13 found13 that differences13 in growth13 do not appear13

to occur until fish are over 450 mm TL at which time growth rate in males slows while

females continue to grow at a slightly higher rate This would indicate that sex may not be

an important factor to consider when examining growth rates unless the target grow-shy‐out

size is above 450 mm TL

The best measures of growth are often determined from13 the length and weight of

individuals rather than from13 groups of fish (Anderson and Nuemannn 1996) because

individual growth rates give better estimates of confidence and variance (Busacker et13 al

1990) Length frequency analysis or recapture of previously marked individuals of a known

size is likely to yield the most useful information for razorback sucker growth The success

of any of these methods depends on proper sampling procedures that are representative of

the population as a whole (Busacker et al 1990) Sampling methods that are known to be

size-shy‐biased such as trammel nets (Mueller et al 2004) or cast nets should not be used when

trying to measure growth rates13

26

13

Conclusions

For razorback sucker survival is largely associated with stocking size Additional

focused13 research13 is therefore13 needed to13 identify13 ways13 to13 increase13 growth13 rates13 of captive-shy‐

reared13 razorback sucker Growth13 rate13 in fish is controlled13 by many factors including fish

size and age temperature density and feed ration which can all be highly correlated

Growth of razorback suckers is also inherently variable which makes the task of identifying

the key factors that13 affect13 growth in13 captivity even more difficult The focus at most

razorback rearing facilities13 is production so the13 types13 of data that are13 collected13 are13 often

insufficient for detailed13 evaluations13 of individual rearing13 practices13 on growth13 Surveys of

existing13 razorback sucker13 rearing facilities indicate that culture methods vary widely and

the types of growth data13 that13 are collected are not13 standardized13 Replicated studies with

detailed information on rearing location water temperature initial stocking size stocking

density and the sizes of all fish at harvest are needed in order to compare the effects of

individual rearing practices on growth This type of research will ultimately provide both

time and cost-shy‐savings to production facilities by reducing the amount of time necessary13 for

razorback sucker to reach stocking size improving overall production efficiency

Optimum13 rearing densities for razorback sucker larvae and juveniles remain to be

determined Current stocking densities will be very useful as starting point for more

detailed studies and although optimum13 rearing densities are likely to be site-shy‐specific13

replicated studies on density will provide a valuable reference for hatchery managers

Frequency13 of sorting is another13 area that needs13 further13 research Frequent

handling13 and13 sorting13 can13 cause13 stress-shy‐related13 reductions13 in growth but not sorting can

create dominance hierarchies that further reduce growth rates of subordinate individuals

The effects13 of sorting13 on overall fish growth13 in both13 pond and13 intensive13 culture13

environments warrant further investigation Research techniques for these types of

experiments are well understood and typically utilize a matrix of replicate ponds per

variable (Bays et al 2005) In every case accurate and complete records of sampling

procedures and data collection are needed in order to interpret data and make inferences

about13 growth rates (Busacker et13 al 1990)13

27

13

Additional research is also needed to evaluate long-shy‐term13 survival of stocked fish

reared in ponds compared to fish13 reared13 in intensive13 culture13 facilities13 Exercise13

conditioning13 and predator-shy‐recognition training may also increase survival of stocked fish

and be more economically feasible than rearing fish to increasingly larger sizes prior to

stocking13 The success13 of traditional fish hatchery programs is measured largely by the

number of fish stocked but hatchery programs for endangered species must measure

success in terms of long-shy‐term13 survival and species recovery (Brannon 1993 Anders 1998)

A specific list of research recommendations follows

Specific Research13 Recommendations13

bull Use replicated studies13 to establish optimum stocking13 densities13 for ponds13 and

tanks13 that can be used as13 a starting13 point for site specific refinement

bull Determine if sortinggrading13 improves13 overall growth rates13 in both ponds13 and

intensive culture facilities13

bull Investigate the use of artificial fertilizers13 to improve growth of both juvenile

and adult razorback suckers13 in ponds13

bull Determine if the razorback sucker diet gives13 better growth rates13 than cheaper

catfish or salmon feeds

bull Evaluate growth rates13 and production potential of new intensive culture

methods13 such as13 large circular tanks13

bull Evaluate13 long-shy‐term survival of fish produced from raceways13 and circular tanks13

compared to fish reared in ponds13

bull Evaluate more effective means13 of treating13 fish diseases13

bull Evaluate factors13 other than size that may increase post-shy‐stocking13 survival such

as13 exercise conditioning13 predator recognition training or rearing13 under more

natural settings13

28

13

II The Effect of Disease Treatments on Razorback Sucker

Growth

Section13 SummaryFormalin copper sulfate potassium permanganate and13 salt are all chemicals commonly13 used13 to13 treat13 Ichthyophthirius multifiliis outbreaks in captive razorback sucker (Xyrauchen13 texanus) Weexposed 190 juvenile13 razorback suckers (127 ndash 26 mm TL) to13 5 5-shy‐day treatments with13 each13 chemical to evaluate the effects13 these chemicals13 may have on growth Fish grew an average of23513 mm TL13 during the month13 study period Fish treated with formalin grew on average13 29mm TL (03 mmday) while fish treated with copper had the lowest growth averaging 20 mmTL (021 mmday) No significant differences in13 growth were observed among fish treatedwith any of the chemicals compared to untreated fish (pgt005) Reductions in growth13 as aresult of repeated chemical treatments are not likely the cause of differences in growth ratesamong13 facilities that raise razorback suckers Repeated chemical treatments may13 have otherimpacts to overall13 fitness or long-shy‐term survival but13 these effects were not13 evident13 in our study

29

13

Introduction

Preservation13 of razorback sucker13 (Xyrauchen texanus) currently13 depends on captive13

rearing and stocking programs until permanent solutions to factors that prevent wild13

recruitment are found Low survival of stocked razorback suckers (Brooks 1986 Marsh

and Brooks 198913 Marsh and Pacey13 2005) has caused target13 sizes for stocked fish to

steadily increase in efforts to reduce predation mortality (Marsh et al 2005 Schooley and

Marsh 2007) Rearing fish to larger sizes at hatcheries comes with increased costs and

creates the need to evaluate husbandry and rearing practices that may affect fish growth

Formalin copper sulfate potassium13 permanganate and salt are all chemicals

commonly used at razorback sucker rearing facilities to treat outbreaks of the protozoan

parasite13 Ichthyophthirius multifiliis ldquoIchrdquo is one of the most pathenogenic diseases of

cultured13 freshwater13 fishes (Matthews13 2005) and causes large13 losses in captive13 populations13

of endangered razorback sucker Each of these chemicals used to treat Ich only kill the free-shy‐

swimming life stage of the parasite13 requiring13 repeated doses over several13 days depending13

on water temperature These chemicals treatments are needed to prevent loss as a result

of disease outbreaks but the cumulative effects repeated disease treatments have on

growth13 are13 unknown

Copper13 sulfate13 has13 been shown to13 significantly13 reduce13 growth13 of channel catfish13 in

production13 ponds (Rabago-shy‐Castro13 2006) but it is unknown whether13 razorback suckers13

experience similar reduced growth following copper treatment Quantifying the impacts of

disease treatments on growth will help to interpret the wide differences in growth rates

observed13 at various13 razorback sucker13 production13 facilities13 throughout the13 southwest

(Ward et al 2007) If one chemical is found to have less detrimental impacts on growth

than another then it may be preferred for use as a disease treatment We evaluated growth

rates13 of razorback suckers13 under13 replicated13 and13 controlled13 conditions13 to13 assess13 effects13 of

repeated formalin copper sulfate and potassium permanganate and salt treatments on

growth13

Methods

We captured 190 juvenile razorback suckers from13 ponds at Bubbling Ponds Fish

Hatchery AZ using hoop nets or cast nets All fish were of the same age class and

30

13

averaged 179 mm total length (TL) (range13 = 127 ndash 262 mm TL)13 These fish were13 offspring13

of captive13 razorback sucker13 broodstock held13 at Dexter13 National13 Fish Hatchery13 NM13 (2007

year class) All fish were tagged with passive integrated transponder (PIT) tags and

quarantined for one month prior to the experiment to allow fish to recover from13 tagging

and become accustomed to being held in circular tanks

At the beginning of the study all fish were weighed measured and scanned for

individual tag numbers with 19 randomly selected fish placed into each13 of 10 8-shy‐foot

diameter circular tanks (Figure 2)13 Each13 tank contained13 two13 airstones13 and13 an13 individual

biofilter with a recirculating water pump (31 litersminute) that had been operating for

at least 1 month prior to the experiment to allow bacterial colonies to become

established Two tanks were designated as a control and did not receive any chemical

treatments while the other eight tanks received formalin copper sulfate potassium13

permanganate or salt treatments at two week intervals (two tanks per chemical

treatment) Formalin copper sulfate and potassium13 permanganate were treated at 1 part

per million (ppm) and salt was applied at 30 parts per thousand (ppt) These treatment

rates are commonly used to treat13 razorback13 suckers for ich at Bubbling13 Ponds Fish13

hatchery (Frank Agygos personal communication)

Figure 213 Photo ofexperimental tankswith individualbiofilters and aeration

31

13

Each treatment consisted of a series of doses applied on Wednesday Thursday and

Friday with a 90water change between each dose Biofilters were removed from13 all

tanks and held in a separate holding facility during treatments and then replaced on the

Monday following treatments after a 90water change This schedule allowed fish to be

exposed to chemical treatments for 5 consecutive days without water quality deteriorating

This 5-shy‐day chemical treatment was repeated every two weeks from13 July to October (97

days)13 for a total of 5 5-shy‐day treatments Water temperature in the treatment tanks ranged

from13 13degC (55degF) to 32degC (91degF)

Fish were fed a fixed ration of commercial razorback diet (Silvercup 4mm13 pellet)

once daily13 (2 percent body13 weight per day13 as calculated13 by13 average initial fish weight)13

At the end of the experiment all fish were again weighed measured and scanned for

individual tag numbers Growth of fish in each treatment group was compared using

analysis of variance (ANOVA) Any mortalities13 that occurred during the13 study13 were13

replaced with previously quarantined fish of equivalent size to maintain equal densities in

each13 tank13 but growth13 data was13 only13 recorded for fish which13 survived13 the13 entire13

experiment

Results

Fish at the13 start of the experiment averaged 179 mm TL (Range13 = 127 ndash 262 mm)

with no significant differences in fish length among treatment groups (F(4189) = 00183 p

gt 0999 ANOVA) On average fish grew 235 mm TL (024 mmday) during the 3 month

study13 Fish in tanks13 treated with formalin had the highest growth averaging 29 mm TL (03

mmday) while fish in tanks treated with copper had the lowest growth averaging 20 mm

TL (021 mmday) Fish in the control tanks averaged 213 mm TL in growth (022

mmday) (Figure13 3)13 Formalin-shy‐treated fish grew13 significantly faster than13 any other

treatment group but no13 significant differences in growth13 in length13 or weight were13

observed among fish treated with any of the chemicals compared to untreated (control)

fish (pgt005 ANOVA)

32

13

Figure 313 Average growthof razorback suckersexposed to a series of 5 5-shy‐day chemical treatmentsover a 97-shy‐day13 periodError bars representstandard error

Discussion13

Growth13 rates13 observed13 in our study13 (021 ndash 03 mmday) are low compared to those

reported13 in other13 studies13 of razorback sucker13 growth13 (0213 ndash 18 mmday) (Ward et al

2007) Using recirculating water systems for our study required filters to be removed and

replaced during treatments Stress to fish caused by removing and replacing filters within

the tanks as well as repeated water changes may have led to overall higher stress and

reduced growth rates compared to those reported for unconfined fish Growth in fish is

highly variable and is affected by many different physiological and environmental factors

including fish size density temperature amount of space and food (Brett 1979) We

strived to control each of these factors but other factors may have also influenced growth

in our experimental tanks During mid-shy‐summer water temperatures in the treatment

tanks reached 32degC (91degF) At these warm13 temperatures fish are very susceptible to

bacterial13 infections13 The slightly higher growth exhibited by fish in the formalin and

potassium13 permanganate treatments may have been the result of these two chemicals

33

13

being effective at controlling bacterial infections The differences in growth we measured

among treatment groups were not statistically significant and do not appear13 biologically13

meaningful during the relatively short duration of this study (97 days) although the

cumulative effects of slightly reduced growth could be biologically meaningful over longer

time frames

Reductions in growth13 as a result13 o repeated chemical treatments are not likely the

cause of differences in growth rates among facilities that raise razorback suckers

Repeated chemical treatments may have other impacts to overall fitness or long-shy‐term13

survival but these13 effects13 were13 not evident in our study It is more likely that the parasite

outbreaks themselves are the cause of different growth rates among razorback rearing

facilities rather than the chemical treatments used to treat the parasites We recommend

that hatchery managers continue to use the chemicals that are most effective at controlling

ldquoIchrdquo13 at their individual13 facilities

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower Colorado Rive Multi-shy‐species13

Conservation Plan under Work Task C10 We thank Ty Wolters and Tom13 Burke for their

support of this research and Frank Agygos and Dave Billingsly of the Bubbling Ponds Fish

Hatchery13 for their13 technical assistance13 and13 help with13 collecting13 fish

34

13

III13 Razorback Growth Rates at Bubbling Ponds ndash 2009-shy‐2011

Section13 SummaryExperimental studies at Bubbling Ponds Fish Hatchery AZ have strived to understand

factors that affect razorback sucker growth in captivity and identify ways to improve growthrates and maximize size at release Rather than performing experimental studies that wouldrequire major13 rearrangement (and likely reduced production)13 of hatchery operations our13 studies13 used normal variation in production techniques13 and practices13 to isolate factors13 thatmay modify growth rates

Our initial work identified razorback13 growth rates in13 lined ponds at standard fishdensity as 026 to13 028mmday (789 to 843 mmmonth) No significant differences in growthrate were observed among fish that had been in the pond only during the winter13 periodcompared to fish that had been in the pond the entire year indicating that water temperatures13 at Bubbling Ponds are high enough to allow fish to incorporate feed effectively year-shy‐roundHowever these growth rates are lower than most values reported from the literature fromnatural or semi-shy‐natural pond environments No significant differences in13 growth rate wereobserved13 between large and13 small fish13 within the 150 ndash 29 mm TL13 size range Additional worksuggests13 that razorback suckers13 tagged at over 300 mm TL had reduced growth rates (024mmday 73 mmmonth) as would be expected according to a typical Von13 Bertalanfy growthcurve although growth rates13 were only slightly less13 than the average growth rate for thehatchery (027513 mmday 82513 mmmonth)

Sorting13 to13 separate small fish from large fish after the first year of growth is practicedesigned13 to allow smaller fish to ldquocatch uprdquo to larger fish We found that13 this technique doesappear to13 improve growth rates of smaller fish Growth rates of sorted small razorback suckers(029 mmday 87mmmonth)13 were equal to that13 of larger13 fish (028 mmday 8413 mmmonth)indicating that sorting may have helped to offset their original slower growth trajectory

Bubbling Ponds Fish Hatchery grows razorbacks in 6 long deep ponds lined with heavyplastic 2 long deep13 earthen13 (unlined) ponds and three wide shallow earthen ponds The wideshallow ponds13 have historically produced very large fish at low density but have been found tomaintain much lower fish numbers than deeper ponds We found13 that growth13 rates ofrazorbacks kept at high density (4-shy‐700013 fish)13 in a wide shallow pond grew extremely slowly(024 mmday 726 mmmonth) This growth rate is among the slowest of any fish over theyears of our study and demonstrates that13 though the large ponds may produce large fish at lowdensity13 they are unable to overcome high13 fish13 densities

Finally one of the major factors influencing13 fish13 growth13 in hatcheries is disease onemajor summer-shy‐time disease at13 Bubbling Ponds is the ectoparasite Ich (Ichthiopthirusmultifiliis) To investigate the impact Ich has on razorback growth we eradicated fish from thespring and water conveyance ditch that supplies13 water to the hatchery using Rotenone This13 restoration effort was fairly short-shy‐lived (Ich returned to the hatchery within four months) but

35

13

growth13 rates of fish13 reared for four months without Ich present (031 mmday 92 mmmonth)were significantly higher than the following 8 months of growth for those same fish (022mmday 65 mmmonth) This disease-shy‐free growth rate is in fact faster than any13 otherprevious growth rates observed at the hatchery in our study

We conclude that growth rates at the Bubbling Ponds Fish Hatchery are likely as highas possible given the pond densities required to13 meet production goals and the Ich-shy‐infestedwater13 that feeds the facility Sorting practices are successful in helping as many fish as possiblereach stocking length as fast as possible Unlined ponds may be able to grow large fish at lowdensities but whatever factors allow for that growth13 are not able13 to overcome13 high fish densityThus the large lower ponds at Bubbling Ponds may be better utilized via renovation to13 deepenand line them

Disease is the most important factor limiting growth as may be expected to be the caseat many13 hatcheries While the spring renovation was not13 a complete success13 the dramaticreduction of fish populations in that habitat was enough to dramatically13 reduce13 the13 occurrenceof Ich at the hatchery13 Such open spring13 systems feeding a hatchery are a misfortune that canbe expected to transmit disease so we suggest that renovating the spring again to combat13 IchImproved techniques to divert water from13 the springs and more throuough treatment ofstream-shy‐side vegetation may improve the success of chemical treatment Successful renovationwould likely both improve growth rates and reduce chemical costs associated with treating Ichoutbreaks Even13 if complete renovation13 is impossible or impractical an13 effort to reduceinvasive fish density in the springs13 which act a vector for the parasite(and thereby reduce thelikelihood of13 Ich being transmitted into ponds) may still13 show dramatic improvements

36

13

Introduction

Conservation efforts13 for razorback sucker13 (Xyrauchen texanus)13 currently13 depend on

captive rearing and stocking programs Low survival of stocked razorback suckers (Brooks

1986 Marsh13 and13 Brooks13 1989 Marsh13 and13 Pacey13 2005) has13 caused13 target sizes for stocked13

fish to steadily increase in efforts to reduce predation mortality13 (Marsh13 et al13 2005

Schooley and Marsh 2007) Rearing fish to larger sizes at hatcheries comes with increased

costs and creates the need to evaluate husbandry and rearing practices that may affect fish

growth13 We evaluated growth13 rates13 of individual razorback suckers13 in ponds13 at Bubbling

Ponds Fish Hatchery13 using Passive Integrated13 Transponder (PIT) tags13 to13 obtain13 precise

growth information for individual fish so that valid comparisons of growth rates as related

to rearing practices can be made

Due to the critical nature of the razorback sucker stocking program we did not

design experimental studies that would require major rearrangement and potentially

reduce production of hatchery operations Instead our studies used normal variation in

production techniques and practices to isolate factors that may modify growth rates

Though this methodology dramatically limits replication and may limit our ability to

directly13 attribute13 differences in growth13 rates13 to13 the13 variables13 we13 investigate13 we13 were13 able13

to accomplish research goals without altering hatchery operations or impacting

production

From13 2009 through 2011 we conducted a series of observational13 growth13 studies to

determine growth rates of individual razorbacks at Bubbling Ponds The first set of

experiments included13 identifying13 growth13 rates13 in lined13 and13 unlined13 ponds determining

growth13 rates13 of fish at different13 sizes13 in13 relation13 to sorting13 practices and monitoring

razorback growth rates after removing the source of the ectoparasite13 Ich (Ichthiopthirus

multifiliis) from13 the hatchery water source13

Razorback growth rate in lined ponds

Our first growth study documented individual growth rates at normal density in 11

million gallon lined ponds13 over two13 years13 This is the standard13 grow-shy‐out process for

razorbacks13 at Bubbling Ponds We monitored growth of fish for a variety13 of sizes and13 the13

37

13

amount of time in a pond during the growing season These13 data give a snapshot of growth13

rates13 at the13 facility13 and13 provide13 the basis for comparisons throughout our study

Growth rate13 in an unlined pond

In addition13 to 6 ponds lined with heavy plastic13 sheeting13 Bubbling Ponds Fish13

Hatchery maintains two narrow and deep (same dimensions as lined ponds13 Figure13 4)13 and13

three large13 shallow unlined ponds These earthen13 ponds typically have vegetation and

associated aquatic invertebrates that may better simulate natural environments by

providing cover and improved food diversity or quality Therefore these unlined ponds

may be expected to produce higher growth rates and potentially improved survival that is

more similar to growth rates observed in more natural grow-shy‐out facilities13 Historically13 the13

large13 shallow13 ponds have produced very large fish when13 utilized at low13 fish density13 The

narrow13 deep earthen13 ponds are13 used to grow13 fry13 at high density in their first13 year of life

The major downside to unlined ponds is the difficulty in harvesting fish where a lined

pond might take 8-shy‐1013 people13 a half13 day13 to13 harvest13 lined13 ponds13 require13 intensive13 weeding13

to allow seines to be pulled and therefore require many more personnel-shy‐hours13 In addition13

to harvest challenges the shallow earthen ponds tend to suffer from13 dissolved oxygen

crashes during the summer Unlined ponds also may maintain higher13 populations13 of non-shy‐

target species such as bluegill sunfish mosquito fish and bullfrog tadpoles We measured

growth rates of suckers in a large shallow earthen pond for comparison to growth in lined

ponds13

Figure13 4 Lined13 and13 earthen ponds13 of similar dimensions (approx 1000000 gallons first

and second panels) and a large13 shallow13 earthen13 pond (third panel)

38

13

Effect of sorting on growth

Razorback13 suckers13 are13 currently13 sorted13 after their first13 year of growth13 They are13

typically removed from13 one of the13 upper earthen13 ponds and13 split into13 two13 lined13 ponds for

subsequent grow-shy‐out13 The larger13 fish (gt approximately 140 mm) are placed into one pond

and the smaller individuals in another It is possible that the larger fish were more

aggressive or adept13 at taking food so this sorting process is intended to allow smaller fish

to improve their growth rate

Effect of Ich on razorback sucker growth rates

We13 evaluated13 growth13 rates13 of razorback sucker13 in the13 presence13 and absence of the

ectoparasite13 Ich (Ichthiopthirus multifiliis) Ich outbreaks can occur in wild populations13 but

hatcheries13 have13 proven excellent locations13 for Ich because13 of very high fish densities13 which13

facilitate13 the13 transfer13 of Ich13 between13 fish This common fish parasite causes direct mortality13

to razorback13 suckers as well13 as secondary bacterial13 infections13

The open spring and13 ditch13 which13 provides water to the Bubbling13 Ponds Hatchery

has long13 been infested with mosquitofish (Gambusia affinis) that harbor13 the13 Ich parasite13

and allow13 it13 to enter the hatchery with incoming13 water13 The solution13 to13 the13 Ich problem13

was to remove the mosquitofish host using13 Rotenone Razorback13 sucker growth13 rates were13

then tracked in13 the absence of this parasite for 4 months and compared with growth rates

after Ich returned to the pond and from13 previous years

Methods

Razorback growth rate in lined ponds

On May 14 2008 141 razorback suckers were tagged with 12 mm PIT tags (1342

kHz) and placed in Pond 3 (approximately 1100000 gallons13 Figure13 4)13 at Bubbling13 Ponds

Fish Hatchery Fifty-shy‐three of these tags were recovered two months later when a large

Ichthyophthirius multifilis (Ich) outbreak killed many fish in the pond On October 15 2008

an additional13 145 PIT tagged13 fish were13 also placed into Pond13 3 On13 May13 14 2009 Pond13 3

was harvested and a total13 of 141 PIT tagged fish were recovered13 Of the tagged fish13 26 fish

had13 been13 in the13 pond since May13 of 2008 (378 days13 o growth) and 115 had been13 in13 the

39

13 40

pond since October13 15 2008 (211 days13 of growth) Numbers of fish in Pond 3 after the Ich

outbreak and for the majority of the period of growth were between 3 000 and 4000 fish

A Hobotempreg temperature13 logger13 was13 also13 installed13 in Pond 3 one meter below the water

surface13 near13 the13 outflow and13 recorded water temperature every 3 hours to allow analysis

of the effects of water temperature on growth rate (Figure13 5) This Hobotemp data is

representative of other pond temperatures throughout this study

In a second experiment 210 adult13 razorback suckers13 were13 PIT tagged13 on13 May 14

2009 and13 placed13 into13 Pond13 3 upper to13 evaluate13 growth13 rates13 of larger13 razorback suckers13 at

Bubbling13 Ponds Hatchery13 under current13 rearing13 conditions13 Size of these fish at tagging13

was (mean = 285 mm range = 205 ndash 396 mm) These fish remained in the pond for 257

days and were harvested on Jan 25 2010 to provide information on growth rates of larger

razorback suckers13 under13 current rearing conditions

Figure 513 Temperatures (degC) inrearing pond at BubblingPonds Hatchery from July toSept 2009 (top graph)13 andfrom Nov to Dec 2009 (Lowergraph) Temperaturesrecorded with a Hobotempregremote data logger13 every 3hours

13

Growth rate13 in an unlined pond

To document razorback sucker growth in earthen ponds we introduced13 225 tagged13

razorback suckers13 into13 Pond13 1 lower13 (Figure 4) in February 3 2010 Additional tagged fish

from13 other studies were added to the pond throughout the growing season and the density

of 1 lower reached a maximum13 of nearly 7000 fish in early summer 2010 Density was

reduced to approximately 6000 fish by capturing fish with hoop nets on June 3 2010 54 of

these fish were tagged fish and returned to 1 lower after being weighed and measured The

pond was harvested on January13 2713 2011 and a total13 of 254 tagged fish out13 of 4296 fish

total were removed from13 the pond The pond was harvested on January 27 2011 (358 days13

of growth) and the tagged fish were weighed and measured Total number of razorbacks in

the pond at harvest13 was 4296

Effect of sorting practices on growth rates

On March 1113 200913 Pond13 5 upper was13 harvested13 and13 split into13 two13 separate13 groups

Two hundred of the smaller fish (average size = 122 mm TL) were PIT tagged and placed

into13 Pond13 7 upper and13 200 of the13 larger13 fish (average = 160 mm TL) were PIT tagged and

placed int Pond13 8 upper Density13 in Pond13 7 was13 4500 fish and13 in Pond13 8 there13 were13 6500

fish These ponds were then harvested after 1 year and growth rates were compared to

give information on the effects of current sorting practices Hobotempreg temperature

loggers were installed in13 Ponds 7 and13 8 during13 the13 grow-shy‐out period with13 water13

temperature recorded every 2 hours13 (Figure13 6)

Effect of Ich on razorback sucker growth rates

Bubbling Ponds spring was treated with Rotenone (CFT Legumine 5) at a

concentration of 2 ppm13 to remove all mosquitofish from13 the spring The treatment

consisted of two treatments 6 hours in duration on two consecutive days (April 12 -shy‐ 13)

using13 drip13 stations13 and13 backpack sprayers13 followed13 by13 an13 additional 6 hours13 of

detoxification using sodium13 permanganate Although 12 mosquitofish were captured in the

spring pond the week following the treatments subsequent minnow trapping (20 traps

checked13 daily13 for 3 weeks) did not capture any additional fish until August 11 2010 when

41

13

juvenile mosquitofish were again detected in the spring pond Minnow traps have

subsequently been set daily with several hundred individuals removed To evaluate if Ich

was also again present in the spring we captured 15 mosquitofish from13 the spring pond on

three separate days and placed them13 in an aquaria at 25 degC with 5 longfin dace known to be

free of Ich These fish were monitored for 2 weeks with no signs of Ich developing This

indicates that even though mosquitofish have returned to the spring pond the parasite is no

longer present13 although how13 long13 this condition13 will13 persist13 is unknown13

On May 1113 201013 200 juvenile razorback13 suckers were harvested out13 of Pond 5

upper (2009 year Class from13 Dexter National Fish Hatchery) and were PIT tagged and

placed into Pond 8 to evaluate if growth rates at bubbling ponds hatchery have improved

following the renovation of the spring and the removal of the Ich parasite Unfortunately13

on Sept13 8 2010 Ich was13 again13 detected13 in Pond 8 and the pond was immediately seined

and 74 tagged fish were measured to obtain growth information for the 4-shy‐month period

during13 which13 the13 pond13 was13 Ich-shy‐free13

Figure13 6 Temperatures (degC) in rearingponds 7 and 8 at Bubbling Ponds Hatchery13 from March 2009 ndash March 201013 pond 7(top13 graph)13 and13 pond 8 (Lower13 graph)13 Temperatures recorded with a Hobotempregremote data logger every 3 hours

42

13

Results

Growth in Lined Ponds

Razorback suckers13 that had been13 in13 Pond 8 upper for the13 entire13 year13 grew an13

average of 0263 mmday (789 mmmonth) and razorback suckers that had been in the

pond for 7 months (Oct -shy‐ May) grew13 on13 average of 028 mmday (843 mmmonth) (Figure13

7) These growth13 rates13 did not significantly13 differ Fish density13 in Pond 3 during13 the13

majority of the growth period was13 00032 ndash 00036 fishgallon13 Additionally no13 significant

differences in growth rate were observed between fish smaller than 210 mm TL and fish

larger than 210 mm TL when all recaptured fish were combined

We also measured the growth rate of very large fish in a lined pond On Jan13 2513 201013

156 adult fish with PIT tags were recovered from13 Pond 3 upper13 These fish were13 in the13

pond for 257 days and experienced an average13 growth13 rate13 of 024mmday or 73

mmmonth (Figure13 7)13 This growth13 rate13 is slightly13 lower13 than13 the13 average13 growth13 rate13

observed13 at Bubbling13 Ponds Hatchery in other studies (0275 mmday 825 mmmonth)

but may not be biologically meaningful We would expect larger13 fish to13 have13 reduced

growth rates according to a typical Von Bertalanfy growth model (Bertalanffy 1957) but it

appears that13 over the size range we evaluated (300 -shy‐ 450 mm TL) growth rates have not

slowed significantly compared to that of smaller13 fish grown at Bubbling Ponds13 Hatchery

Growth13 of razorback suckers13 is known13 to13 slow as13 fish reach13 larger13 sizes but it appears13 this13

reduced growth rate may not really start to be biologically meaningful at Bubbling Ponds

Hatchery13 until razorback suckers13 exceed 450 mm TL

Growth in unlined ponds

Growth13 rates13 for the13 fish recaptured13 during13 the Pond 1 lower13 thinning13 (120 days13 in

the pond) was 024 plusmn 003 mmday (729 plusmn 090 mmmonth) (Figure13 8)13 Fish13 that were13 in

the pond for nearly the entire year grew13 an13 average13 of 024 plusmn 001 mmday (726 plusmn 027

mmmonth) These growth rates are surprisingly the lowest measured growth rates for

any part of our study and differ significantly from13 every other measured growth rate

except very large13 fish (Figure13 9)13 Separating13 out13 large fish that13 were in13 the pond for the

entire year makes no difference fish that were added to the pond at TL lt300 mm grew

43

13

Gro

wth

Rat

e (m

md

ay)

020

026

032

0244 plusmn 001 mmday (733 plusmn 028 mmmonth) and and those with TL gt= 300 mm at the

start of the experiment grew 022 plusmn 003 mmday (651 plusmn 101 mmmonth)

Razorback Growth Rates in Lined Ponds

Figure 7 Growth ofrazorback suckers in(mmday plusmn standard error)in Pond 8 upper in 2008-shy‐2009 An ANOVA did notdetect any significantdifferences

7 Months Full Year 300+ mm fish

Effects of sorting on growth

One hundred and seventy five tagged razorback suckers were recovered from13 Pond

8 upper13 on March13 24 2010 (378 days13 of growth)13 These were13 the13 larger sorted13 fish (gt140

mm TL) that came out of Pond13 5 on March13 11 2009 One13 hundred and13 twenty13 two13 tagged13

razorback suckers were also recovered from13 Pond13 7 upper on March13 31 2010 (385 days13 of

growth)13 These were13 the13 smaller sorted13 fish (lt140 mm TL) that came out of Pond13 5 on

March 1113 200913 No significant differences in growth rate (mmday) were observed among

larger fish in Pond 8 and smaller fish in Pond 7 (pgt005 ANOVA) (Figure 10)13 indicating

that13 sorting may have helped to offset the original slower growth trajectory of the smaller

fish Temperatures of Ponds 7 and 8 upper remained similar throughout the year13 (Figure

5)

44

13

13

13

Gro

wth

Rat

e (m

md

ay)

Gro

wth

Rat

e (m

md

ay)

020

026

032

020

026

032

Razorback Growth in an Unlined Pond

Figure 8 Growth of razorbacksuckers (mmday plusmn standard error) in Pond 1 lower (an unlined pond)in 2010-shy‐2011 An ANOVA did notdetect any significant differences

6 Months 12 Months lt 300 mm Fish 300+ mm Fish Growth Growth

Lined vs Earthen Ponds 1 year of growth

Figure 9 Growth of razorbacksuckers (mmday plusmn standard error) in lined and unlined ponds A t-shy‐test13 did not detect a significantdifference

Lined Pond Unlined Pond 1 Yr Growth 1 Yr Growth

45

13

Effect of Sorting G

row

th R

ate

(mm

day

) G

row

th R

ate

(mm

day

)

032

020

026

032

020

026

Smaller Fish Larger Fish

Effect of Ich

Figure 10 Average growthof razorback suckers(mmday plusmn standard error)that were size-shy‐sorted intosmall fish (pond 7) and largefish (pond 8) populations At-shy‐test did not detect asignificant difference

Figure 11 Average growth ofrazorback suckers (mmday plusmnstandard error) after Ich wasremovd from the hatcheryrsquos springand after Ich was again detected inthe pond The growth rate withoutIch is significantly higher than boththe rate after Ich and the ourstudyrsquos average annual growth ratein lined ponds (ANOVA p =00003)

Growth without Ich Growth With Ich Average Annual 4 months 4 months Growth Rate

46

13

Effect of Ich on razorback sucker growth rates

Seventy-shy‐four13 tagged13 razorback suckers13 were13 recovered from13 Pond 8 on September

15 2010 These fish had13 been13 in the pond for 4 months and experienced a growth rate of

032 mmday or 97 mmmonth (Figure13 11)13 This growth13 rate13 is significantly higher (p =

005 two sample t-shy‐test) than the mean growth rate for the same group13 of tagged fish after

Ich detection (022 mmday or 65 mmmonth) and significantly higher than any other

individual growth13 rates13 observed13 to13 date13 at Bubbling13 Ponds Hatchery13 (Figure13 11)13 If this13

growth13 rate13 were13 extended throughout13 the entire13 year13 fish on average from13 Ich-shy‐free13 ponds13

would be 16 mm longer than fish from13 ponds infested with Ich Studies conducted at

Bubbling Ponds hatchery in 2008 (Ward 2008) did not reveal any effects of the treatment

chemicals on razorback sucker growth rates so it13 is likely that13 the parasite outbreaks

themselves are causing reducing growth rates rather than the chemicals used to treat the

parasites13

Conclusions

Our results suggest that under typical hatchery operations (maximizing number of

fish produced)13 the growth13 rate13 of razorback13 suckers13 is relatively13 consistent at Bubbling13

Ponds hatchery13 at 02-shy‐03 mmday (6-shy‐9 mmmonth)13 but is lower than growth13 rates13 at

other13 facilities (02 ndash 18 mmday Ward et al 2007)13 This growth13 rate13 has13 been13 constant in

both lined and unlined ponds and at all fish densities we were able to measure To achieve13

growth13 rates13 substantially higher than this will likely require13 significant changes in rearing

practices that may not be practical in order to reach numerical production13 goals

Temperature is a key variable in fish growth but seasonal growth patterns

described13 above13 (Figure13 5) demonstrate that water temperatures are high enough in

winter to maintain razorback growth Differences in water temperature by season

currently13 do not fluctuate more than 10degC at Bubbling Ponds because of the continuous

supply of water flowing through each pond (approx 225 gallonsmin) These high water

flows appear to keep pond temperatures within the thermal preference13 for razorback

suckers13 (1213 -shy‐ 28 degC Bulkley and Pimentel 1983) throughout the entire year with

temperatures rarely dropping13 below 16deg13 C (Figures 513 6)13

47

13

Fish density is another key variable in fish growth and though the number of fish in

a pond during our study ranged from13 3000 to 700013 fish we13 did not find any13 correlation13

between13 density and growth rate13 This might yield two conclusions First13 razorback

growth13 may be changed equally13 by13 densities13 at the13 hatchery13 (ie13 a density13 of 3000 fish in a

pond is as stressful13 for razorbacks as a density13 of 7000 fish) An alternative is that other

factors13 such as disease outbreaks have13 stronger13 control over fish growth13 than13 density13

Fish density13 would13 have13 to13 be13 experimentally manipulated to test13 this13 and hatchery

operations (producing the maximum13 number of fish) prevented our manipulating density13

in ponds for this13 work The trouble with manipulating density demonstrates the difficulties

associated with changing13 hatchery13 practices experimenting with density would have

prevented BPH from13 meeting13 production13 goals Given that the stocking of smaller

razorbacks has met with very little success perhaps BPH goals could be changed from13

producing 12000 fish at 300+ mm per year to a smaller number of very large fish each

year Growing13 fewer13 larger13 fish could potentially be accomplished in the same time frame

as more smaller fish but a better understanding of how density alters growth rate would

be required to be confident13 of this

The very slow growth13 in the13 earthen13 unlined13 Pond 1 lower13 was very surprising We13

had13 anticipated13 that the13 diversified diet13 cover and13 other13 habitat features13 provided by13

unlined ponds would yield dramatically increased growth rates However these traits were

not enough to offset high fish densities and in fact the unlined pond in our study13 suffered

mortality to bring densities down to that observed normally in lined ponds

Our data13 suggest13 that razorbacks13 sucker13 growth13 rates13 are13 higher in lined13 ponds13

However we13 think the reasons13 for the13 very slow growth we observed13 in the13 unlined13 pond13

in our study13 is instead13 linked13 to13 the13 usage13 of Pond 1 lower13 during13 the13 study13 rather13 than13

intrinsic13 slow growth13 in earthen13 ponds First the pond was at extremely high density for at

least part of the study The volume of Pond 1 lower has not been estimated but hatchery

managers suggest 1500-shy‐2000 fish is an appropriate number of individuals so this pond

was at a very high density for much of the experiment Second dissolved oxygen is often

very low in the13 large13 earthen13 ponds during the heat of summer much lower than that of

lined ponds This will both limit the number of fish that can survive in the pond and almost

certainly13 increases stress13 of these13 fish potentially13 reducing growth13 The DO crashes also13

48

13

limit the amount of feed hatchery managers can give fish in these ponds sometimes for

days or weeks at a time which further reduces growth during warm13 weather

Our data13 suggests that13 growth rates at the Bubbling13 Ponds Fish Hatchery are likely

as high as possible given13 the pond densities required to meet production goals and the Ich-shy‐

infested water that feeds the facility Sorting practices are successful in helping as many

fish as possible reach stocking length as fast as possible Unlined ponds may be able to

grow13 large13 fish at low13 densities13 but whatever factors allow13 for that13 growth are not13 able to

overcome high fish density The removal of invasive13 fis that act as13 a host for the13 parasite13

Ich fish from13 the Bubbling13 Ponds spring13 allowed the highest13 growth rate at 032 mmday13

(96 mmmonth) but that growth rate decreased again as Ich re-shy‐infested13 the13 hatchery13

Consistently13 achieving13 growth13 rates13 as high or substantially13 higher than13 this13 will likely13

require13 significant changes in rearing practices that may not be practical in order to13 reach13

numerical production13 goals

Two major changes that might result in higher growth rates are substantially

reducing fish density and modifying the way spring water is delivered to the facility (via

either repeated chemical treatments or enclosed concrete water diversions) to eliminate

Ich from13 the hatchery source water Other potential changes not address by our work

include13 flow-shy‐training razorbacks much previous literature including MSCP-shy‐funded13 work

on razorback suckers13 suggests13 that fish growing13 in flowing water will grow13 faster than fish

in still water (Jorgensen and Jobling 1994) Furthermore there are a wide variety of

potential benefits associated with growing13 fish13 in flowing13 water in addition13 to increased

growth13 rates13 (Davidson13 199713 Castro13 et al13 2011) Another option13 for increasing13 growth13

rates13 include13 changing to13 intensive13 culture13 in large circular13 tanks

Finally given that the stocking of smaller razorbacks has met with very little

success13 perhaps13 BPH13 goals13 could13 be13 changed from13 producing 12000 fish at 300+ mm per

year to a smaller number of very large fish each year Growing fewer larger fish could

potentially be accomplished in the same time frame as more smaller fish but a better

understanding13 of how density13 alters growth13 rate13 would13 be13 required to13 be13 confident of this

49

13

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower13 Colorado13 River Multi-shy‐Species13

Conservation Program13 (LCRMSCP) under Work Task C10 We13 thank Ty Wolters13 Tom13

Burke13 and Eric13 Volkman for their support of this research and Frank Agygos and Dave

Billingsly13 of the Bubbling13 Ponds Fish Hatchery13 for their willingness to participate in13 this

research13 and13 for their technical assistance We also thank the LCRMSCP fish group from13

Boulder City13 NV for their assistance with harvesting13 ponds and tagging13 fish13

50

13

Literature13 CitedAnders P J 1998 Conservation aquaculture and endangered species can objective science13

prevail13 over risk13 anxiety Fisheries 23(11) 28-shy‐31

Anderson R O and R M Nuemann 1996 Length weight and associated structural indicesPages 447 ndash 482 in B R Murphy13 and D13 W Willis13 editors13 Fisheries techniques13 2ndedtion American Fisheries13 Society13 Bethesda13 Maryland

Bain M B J T Finn and H E Brooks 1988 Streamflow regulation and fish communitystructure13 Ecology13 69382-shy‐392

Bays J H Zarbock R Whitman and T Murphy 2005 Conceptual design and managementof native13 fish refugia on the13 lower13 Colorado13 River In13 CL Spring13 and13 S Leoneditors Proceedings of two symposia Restoring native fish to the lower ColoradoRiver13 interactions13 of native and non-shy‐native13 fishes 13ndash1413 July13 1999 Las13 Vegas13 Nevada13 Restoring13 natural function within a modified riverine environment thelower Colorado River13 8ndash913 July13 1998 U S Fish and13 Wildlife13 Service Southwestern13 Region Albuquerque New Mexico Pages 167-shy‐177

Bertalanffy L Von 1957 Quantitative laws in metabolism13 and growth13 Q Rev Biology 32217 ndash 231

Bingham T B Scheer and C McAda 2003 Propagation facilities in Grand Valley (24 RoadHatchery Horsethief13 Ponds and13 grow-shy‐out ponds) for captive13 rearing13 ofendangered13 fishes for the13 upper13 Colorado13 River basin13 Colorado River RecoveryProgram FY2003 annual project report13 US Fish and13 Wildlife13 Service GrandJunction13 4pp

Birchell G J and K Christopherson 2004 Survival growth and recruitment of larval andjuvenile razorback13 sucker (Xyrauchen texanus) introduced13 into13 floodplain13 depressions13 of the13 Green River Utah13 Final report13 Upper13 Colorado13 RiverEndangered Fish Recovery Program13 Project No C-shy‐6RZ Publication Number 04-shy‐1513 Utah13 Division of Wildlife13 Resources Salt Lake13 City13 Utah13 67 pages

Brannon E L 1993 The perpetual oversight of hatchery programs Fishery Research 1819-shy‐27

Brett J R 1979 Environmental Factors and growth pages 599-shy‐67513 InW S Hoar13 D13 J13 Randall and J R Brett (eds) Fish Physiology Volume 8 Bioenergetics and GrowthAcademic Press New York

Brooks J E 1986 Annual reintroduction and monitoring report for razorback suckerXyrauchen texanus in the Gila River Basin Arizona 1985 US Fish and WildlifeService13 Offices of Endangered13 Species and Fishery13 Resources Albuquerque 23 pp

51

13

Brunson13 R E and K D13 Christopherson13 200513 Larval13 razorback13 sucker and bonytailsurvival and13 growth13 in the13 presence13 of nonnative13 fish in the13 Baeser13 floodplainwetland of the middle Green River Final report prepared for Upper13 Colorado RiverBasin Endangered Fish Recovery Program Project No C-shy‐6-shy‐rz-shy‐bt Publication13 No 05-shy‐26 Utah13 Division of Wildlife13 Resources13 Vernal13 32 pp

Bulkley R V and R Pimentel 1983 Temperature preference and avoidance by adultrazorback suckers Transactions of the American Fisheries Society 112601-shy‐607

Burke13 T13 199513 Rearing13 wild razorback13 sucker larvae in13 lake-shy‐side13 backwaters13 LakeMohave ArizonaNevada Proceedings of the Desert Fishes Council 2635

Busacker G P I R Adelman and E M Goolish13 199013 Growth13 Pages 363 ndash 387 in C BSchreck and p B Moyle editors Methods for fish biology American FisheriesSociety Bethesda Maryland

Castro V B Grisdale-shy‐Helland S J Helland T Kristensen S M Jorgensen J Helgrud13 GClaireaux A P Farrell A Krasnov and H Takle 2011 Aerobic training stimulatesgrowth and promotes disease resistance in Atlantic salmon (Salmo salar)Comparative Biochemistry and Physiology -shy‐ Part A Molecular amp IntegrativePhysiology13 160(2) 278-shy‐290

Czapla T E 2002 Facilities plan for the production of endangered fishes to meet statestocking13 plans13 as13 part of the13 Upper13 Colorado13 River Endangered13 Fish RecoveryProgram Upper Colorado River Basin Recovery Implementation Program US Fishand Wildlife Service13 Denver13 9 pp

Davidson W 1997 The effects13 of exercise13 training on teleost fish a review of recentliterature Comput Biochem Physiol 117A67ndash75

Figiel Jr C R 2005 Annual report fiscal year 2004 Willow Beach National13 Fish HatcheryUS Fish and Wildlife13 Service Willow Beach 17 pp

Figiel Jr C R M E Ulibarri G Carmichael J Seals and J N Hanson 2005 Intensive13 fish13 culture of warmwater native fishes at a coldwater fish hatchery Pages 164-shy‐16613 inProceedings of two symposia restoring native fish to the lower Colorado13 River13 interaction13 of native13 and13 non-shy‐native13 fishes July13 13-shy‐1413 1999 Las Vegas Nevada USFish and Wildlife Service Southwest Region Albuquerque New Mexico

Gerking13 S D 1978 Ecology of freshwater fish13 production13 Halstead Press13 New13 York

Gustafson W and Q Bradwisch 2000 Wahweap operation and maintenance -shy‐-shy‐ UtahColorado River Recovery Program FY 2000 annual project report Project No 29cUtah13 Division of Wildlife13 Resources Page AZ 3pp

52

13

Hamman R L 1985 Induced spawning of hatchery-shy‐reared13 razorback sucker ProgressivFish Culturist 47(3) 187-shy‐189

Hanson J N 1996 Annual report fiscal year 1996 Willow Beach National Fish HatcheryUS Fish and Wildlife Service13 Willow Beach 9pp

Irving D S Seversen and M Montagne 2004 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2004 annual project13 report Report No 29b US Fish and13 Wildlife13 Service Vernal 3pp

Jorgensen E H and13 M Jobling 1994 Feeding and13 growth13 of exercised13 and13 unexercised13 juvenile Atlantic salmon in freshwater and performance after transfer to seawaterAquaculture International 2 154-shy‐164

Kaeding L R and D B Osmundson 198913 Colorado13 Squawfish13 and13 razorback sucker grow-shy‐out pond studies as part of conservation measures for the green mountain andRuedi reservoir water sales Final report for agreement number 6-shy‐AA-shy‐60-shy‐00150

Koebele13 B P13 198513 Growth and the size hierarchy effect an experimental assessment ofthree proposed mechanisms activity differences disproportional food acquisition13 pysiological stress Environmental Biology of Fishes 12 181-shy‐188

Kretschmann A E and L L Leslie 2006 Razorback sucker (Xyrauchen texanus) status13 reproduction and recruitment in Senator Wash Reservoir CA Final Report13 to USBurea of Reclamation Cooperative Agreement No 00-shy‐FG-shy‐34-shy‐ 0009 p 32 ArizonaGame and Fish Department Phoenix

Marsh13 P13 C13 1987a13 Digestive tract13 contents13 of adult razorback suckers13 in Lake13 MohaveArizona-shy‐Nevada Transactions of the American Fisheries Society 116117-shy‐119

Marsh P C 1987b Native fishes at Buenos Aires National Wildlife Refuge and ArizonaState University Research Park Arizona opportunities for management researchand public13 education13 on13 endangered species13 Proceedings of the Desert13 FishesCouncil 1967-shy‐78

Marsh P C 1994 Rearing native Colorado River fishes in golf course ponds Arizona StateUniversity Tempe 22 + pages

Marsh13 P13 C13 200013 Fish population13 status and evaluation13 in13 the Cibola13 High Levee PondFinal report agreement number 99-shy‐FG-shy‐30-shy‐00051 US Bureau of ReclamationBoulder City13 Nevada13 20 pages

Marsh P C and C A Pacey 1998 Growth of wild adult razorback suckers13 in Lake13 Mohave13 Arizona-shy‐Nevada13 Final report13 US Bureau of Reclamation Boulder City Nevada 25pages + appendices

53

13

Marsh P C B R Kesner and C A Pacey 2005 Repatriation as s management strategy13 to13 conserve a critically13 imperiled fish species North American Journal of FisheriesManagement 25 547-shy‐556

Marsh P C and C A Pacey 2005 Immiscibility of native and non-shy‐native13 fishes Pages 59-shy‐63 inMJ13 Brouder13 CL13 Springer13 and CS13 Leon13 editors13 Proceedings of two13 symposia Restoring native fish to the lower Colorado River interactions of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 NV and13 Restoring natural13 function within a modified riverine environment the lower Colorado River13 July13 8-shy‐913 1998 Las Vegas NV US Fish and13 Wildlife13 Service Southwest Region AlbuquerqueNew Mexico

Marsh13 P13 C13 and J13 E Brooks13 198913 Predation13 by ictalurid catfishes as a deterrent13 toreestablishment of hatchery-shy‐reared13 razorback sucker The Southwestern Naturalist34188-shy‐195

Matthews R A 2005 Ichthyopthirus multifiliis Fouquet and Ichthyopthirosis infreshwater13 teleosts13 Pages13 159-shy‐218 in Advances in Parasitology volume 59 J RBaker R Muller D Rollinson (eds) Academic Press

McCarthy13 M S and W L Minckley 1987 Age estimation for razorback sucker (PiscesCatostomidae) from13 Lake Mohave Arizona and Nevada Journal of the Arizona-shy‐Nevada Academy of Science 2187-shy‐97

Minckley13 W L13 198313 Status of the razorback13 sucker13 Xyrauchen texanus (Abbot)13 in13 thelower Colorado River basin13 The Southwestern13 Naturalist13 28(2) 165-shy‐187

Minckley13 W L13 199113 Native fished of the Grand Canyon13 region an obituary13 Pages 124-shy‐177 in Colorado River ecology and dam13 management National Academy PressWashington13 DC

Minckley13 C13 O and M LaBarbara13 199913 Report13 on13 native fish grow-shy‐out facilities13 at Cibolaand Imperial National Wildlife Refuges 1993-shy‐199513 US Fish and13 Wildlife Service13 Parker Fishery Resources Office Parker Arizona

Modde13 T13 199613 Juvenile razorback sucker (Xyrauchen texanus) in a managed wetlandadjacent13 to the Green13 River13 Great13 Basin13 Naturalist13 56375-shy‐376

Modde T KP Burnham and E J Wick 1996 Population status of the razorback sucker13 inthe middle Green River (USA) Conservation13 biology 10 110-shy‐119

Modde13 T13 and G13 B Haines13 200513 Survival13 and growth of stocked razorback13 sucker andbonytail in multiple floodplain wetlands of the middle Green River under resetconditions13 Final report prepared for Upper Colorado13 River13 Basin RecoveryImplimentation Program US Fish and Wildlife Service Vernal 66 pp

54

13

Modde T Z H Bowen and D C Kitcheyan 2005 Spatial and temporal use of a spawning13 site in the middle Green River by wild hatchery-shy‐reared13 razorback suckers13 Transactions of the American Fisheries Society 134937-shy‐944

Mueller13 G13 199213 The native fish work13 group13 -shy‐ a multiagency endeavor to improve thestatus of the razorback sucker in Lake Mohave AZ-shy‐NV13 Proceedings of the DesertFishes Council 2369

Mueller G 1995 A program13 for maintaining the razorback sucker in Lake MohaveAmerican Fisheries Society Symposium 15127-shy‐135

Mueller13 G13 200613 Ecology of the bonytail13 and razorback13 sucker and the role of offchannelhabitats13 in their13 recovery Scientific13 investigations13 report 2006-shy‐5065 US GeologicalSurvey13 Denver

Mueller G and E Wick 1998 Testing of golf course ponds at Page Arizona for suitability13 as grow-shy‐out facility for razorback sucker using surplus fish from13 Ouray NationalFish Hatchery National Park Service US Fish and13 Wildlife13 Service and UtahDivision of Wildlife13 Resources 28 pages

Mueller13 G13 and T13 Burke13 200513 Survival13 of young13 razorback13 sucker (Xyrauchen texanus) inrelation to13 stocking rates13 (fishha)13 and13 in the presence13 or absence13 of predatorcommunities in Lake Mohave Arizona-shy‐Nevada13 Pages13 155-shy‐16313 in Proceedings of two13 symposia restoring native fish to the lower Colorado River interaction13 of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 Nevada US Fish and Wildlife13 Service Southwest Region Albuquerque New Mexico

Mueller13 G13 J13 Carpenter13 and P13 C13 Marsh13 200413 Cibola13 High Levee Pond annual report 2004US Geological Survey Fort Collins13 Science Center13 Colorado13 and Arizona StateUniversity Tempe 23 pages

Nesler T P K Christopherson J M Hudson C W McAda F Pfeifer and T E Czapla 2003An integrated stocking plan for razorback sucker bonytail and Colorado13 pikeminnow for the Upper Colorado River Endangered Fish Recovery ProgramAddendum13 to State Stocking Plans Upper Colorado River Basin Recovery13 Implementation Program 12 pp

Papoulias13 D and W13 L Minckley13 1992 Effects13 of foo availability13 on survival and growth13 of larval razorback suckers13 in ponds Transactions of the American Fisheries Society121340-shy‐355

Paukert13 C P D L Ward13 P J Sponholtz13 and K13 D Hilwig13 Effects13 of repeated hoopnetting13 on bonytail chub13 Journal of Freshwater13 Ecology13 20(4) 649-shy‐653

Pfeifer F M13 C Baker13 and M13 Montagne13 199913 Propagation13 facilities13 in the13 Grand Valley13 (24 Road13 Hatchery13 Horsethief13 Ponds and13 grow-shy‐out ponds) for captive rearing of

55

13

endangered13 fishes for the13 Upper Colorado13 River Basin13 Colorado13 River Recovery13 Program FY 99 annual project report Project No 29a13 US Fish and Wildlife Service13 Grand13 Junction13 5pp

Pfeifer F S Seversen and M Montagne 2003 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2003 annual reportProject No 29b13 US Fish and Wildlife13 Service Vernal13 4pp

Rabago-shy‐Castro J L Sanchez13 J G Perez-shy‐Castaneda R and13 Gonzalez-shy‐Gonzlez A 2006Effects of the prophylactic use of Romet-shy‐3013 and13 copper13 sulfate13 on growth13 condition13 and feeding13 indicies in13 channel13 catfish (Ictalurus punctatus) Aquaculture 253 343-shy‐349

Reinitz GL L E Orme and F N Hitzel 1979 Variations of body compositio and growth13 among strains of rainbow trout Transactions of the American Fisheries Society 108204-shy‐207

Ruppert13 J13 B P B Holden13 and P D Abate 1999 Age estimation and growth of razorbacksucker13 Xyrauchen texanus in Lake13 Mead Nevada Proceedings13 of the Desert FishesCouncil 3040

Schnoor K D and J Logan 2002 Operation and maintenance of JW Mumma nativeaquatic13 species restoration facility Colorado Colorado River Recovery Program FY2002 annual project report13 Project No 29d Colorado13 Division of Wildlife Alamosa3pp

Salisbury13 L13 1998 Factors13 affecting razorback13 sucker growth13 in Lake13 Mohave backwaters13 MS Thesis13 Unviersity13 of Nevada13 Las13 Vegas

Schooley J13 D13 and P C13 Marsh13 2007 Stocking of endangerdd13 razorback13 suckers13 in thelower Colorado River Basin13 over three decades 1974-shy‐2004 North American Journalof Fisheries Management 27 43-shy‐51

Severson S H H M Tyus and G B Haines 1992 An evaluation of feeds for raisingrazorback sucker Xyrauchen texanus Journal of Applied Aquaculture 155-shy‐65

Toney D P 1974 Observations13 on the13 propagation13 and13 rearing13 of two13 endangered species13 in a hatchery environment Proceedings of the Annual Conference of the Western13 Association of State Game and Fish Commissions 54 252-shy‐259

Tyus H M13 1998 Razorback sucker13 (Xyrauchen texanus) recovery plan13 University13 ofColorado Center for Limnology Boulder13 76 pages

Tyus H M13 and13 S H Severson 1990 Growth13 and13 survival of larval razorback suckers fedfive formulated diets The Progressive Fish Culturist 52197-shy‐200

56

13

Ulibarri M E 2003 Annual report fiscal year 2001 Dexter National Fish Hatchery13 andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 26 pages

Ulibarri M E 2003 Annual report fiscal year 2002 Dexter National Fish Hatchery andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 59 pages

USBR 2006 Lower13 Colorado13 River Multi-shy‐Species Conservation Program final fishaugmentation plan Boulder City 19 pp

USFWS 2002 Razorback sucker (Xyraouchen texanus) recovery goals Amendment andsupplement to the Razorback Sucker Recovery Plan13 US Fish and Wildlife Service13 Region 6 Denver13 Colorado

USFWS 1999 Annual report 1999 Ouray National Fish Hatchery Vernal 25pp

USFWS 2004 Management plan for the big-shy‐river13 fishes of the13 lower13 Colorado13 river basinamendment and supplement to the bonytail humpback chub Coloradopikeminnow and razorback sucker recovery plans

USFWS13 2005 Station13 profile13 of the13 Dexter13 National Fish Hatchery13 and Technology CenterUS Fish and Wildlife13 Service Dexter

Valdez R A P G Mangan R Smith and B Nilson 1982 Upper Colorado River fisheriesinvestigations13 inW H Miller J J Valentine D L Archer H M Tyus R A Valdezand L13 Kaeding13 editors13 Colorado River Fishery13 Project13 Part 2 Field13 investigations13 US Bureau of Reclamation Salt Lake City Utah

WBNFH 2004 Culture methods of the endangered razorback sucker Xyrauchen texanusUS Fish and Wildlife13 Service Willow Beach National Fish Hatchery13 8 pp

Ward D 2008 Effects of disease treatments on growth of razorback sucker ReportSubmitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 Inpartial fulfillment of work task C10 agreement number 06FG30039

Ward13 D13 M Childs and W Persons 2007 Factors13 affecting13 growth13 of razorback sucker13 (Xyrauchen texanus) in captivity Literature review and knowledge assessmentReport Submitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 In partial fulfillment of work task C10 agreement number 06FG30039

57

Appendices

Appendix 1 Survey Questions Survey of Razorback Sucker Culture in the

Southwestern United States

The enclosed survey is being distributed by the Arizona Game and Fish Department to razorback sucker culture facilities throughout

the Southwestern United States The purpose of this survey is to consolidate information regarding culture of this species so that

appropriate facility improvements can be considered for Bubbling Ponds Hatchery in Arizona Specifically we wish to increase

growth rate and production efficiency at the hatchery Information gathered in this survey will be summarized in a final report to US

Bureau of Reclamation in Boulder City NV and disseminated to all facilities that participate in the survey A workshop to discuss

the findings of this study as well as to share general information concerning razorback sucker culture will be organized by the

Arizona Game and Fish Department at the conclusion of this study and all participants will be invited

Thank you for taking the time to fill out this survey Please contact Mike Childs if you have questions or would like to discuss the

survey

Mike Childs

mchildssedonanet

(928) 639-1346

(928) 634-1279

Facility_____________________________________ Date___________________

Contact Phone _____________________________

ContactPerson_______________________________

Contact Email _______________________________

1 Water quality ranges at this culture facility

Season

Spring (Mar-May) Summer (Jun-Aug) Fall (Sept-Nov) Winter (Dec-Feb)

Temperature (C)

PH

DO (mgL)

PO4 (mgL)

TDS (mgL)

Hardness (mgL)

CaCO3

Pathogens

37

13

Introduction

State and federal wildlife management agencies have been rearing razorback

suckers in captivity since the 1970rsquos (Toney 1974 Hamman 1985) to augment declining

natural13 populations Both wild-shy‐caught larvae13 and captive-shy‐bred fish are reared at fish

hatcheries13 and13 grow-shy‐out ponds throughout the13 southwestern13 United13 States13 (reviewed13 in

Mueller 2006) Each facility has unique environmental conditions and different rearing

methods which yield different growth rates Unlike commercial fish species which have

been cultured and studied extensively little published information is available on the

effects of various rearing methods on growth of razorback sucker

Low survival rates13 of stocked13 razorback suckers13 (Brooks13 1986 Marsh13 and13 Brooks13

1989 Marsh13 and13 Pacey13 2005)13 have13 caused13 target sizes for stocking13 to13 steadily13 increase13 in

efforts to reduce predation mortality (Marsh et al 2005 Schooley and Marsh 2007)

Rearing fish to larger sizes comes with increased costs and creates the need to know which

factors13 have the greatest impact on growth rate and how these factors can be controlled to

maximize growth This document compiles and summarizes information on current

captive13 rearing practices13 and associated13 growth13 rates13 for razorback sucker13

We reviewed relevant13 published literature and agency reports on13 razorback13 sucker

to compile background information regarding the effects of environmental factors and

rearing methods on growth A questionnaire was developed (Appendix 1) and sent to

hatchery managers who rear razorback suckers Follow up surveys13 were13 also13 conducted13

by telephone (Appendix 2) Information on rearing densities water quality diseases and

management practices at each facility were recorded Site visits to Bubbling Ponds State

Fish Hatchery13 in Arizona Dexter National Fish Hatchery in New Mexico Grand Valley

Endangered Fish13 Facility13 in Colorado13 Ouray13 National13 Fish13 Hatchery13 in Utah and the Willow

Beach National Fish Hatchery in Arizona were also conducted as part of this knowledge

assessment Telephone interviews were conducted with personnel from13 other locations

that13 produce razorback13 suckers (Uvalde National13 Fish Hatchery13 Hualapai Ponds13 Lake

Mead Fish Hatchery and JW Mumma Fish Hatchery) or facilities that formerly produced

razorback suckers but currently focus on other species (Wahweap Fish Hatchery Achii

Hanyo13 National Fish Hatchery Mora National Fish Hatchery)

9

13

Information from13 all of these sources is summarized to aid future researchers in the

design of more detailed studies on razorback sucker13 growth Understanding the13 factors13

that13 control13 razorback13 sucker growth will13 allow13 expanded fish-shy‐rearing capabilities13 and13 aid13

in reaching management objectives for stocked fish Preservation of genetic resources for

razorback suckers13 depends on captive rearing and stocking programs until permanent

solutions to factors that prevent wild recruitment can be found

Summary13 of Facilities

There are13 over 50 locations13 that have13 been13 used to13 rear13 razorback suckers13 (Table13 1) These

include13 both13 intensive13 culture13 facilities13 with13 raceways13 or circular13 tanks13 as13 well as13

production13 ponds13 golf-shy‐course13 ponds and natural floodplain-shy‐wetlands The majority of

razorback suckers that are stocked come from13 six major production facilities Bubbling

Ponds State13 Fish13 Hatchery13 The Grand13 Valley13 Endangered13 Fish Facility13 and13 Dexter13 Ouray13

Willow13 Beach13 and Uvalde National13 Fish Hatcheries13 Tables 2-shy‐313 outline13 the13 types13 of fish

holding facilities and water quality conditions that exist at each of these main production

locations A brief summary of procedures for rearing razorback suckers at each of these

facilities13 follows

These summaries are based on interviews conducted with hatchery personnel in July 2007 during site visits

This information13 is provided only to give a brief overview of razorback grow-shy‐out procedures Please verify13

accuracy13 of specific information with individual hatchery managers

10

13

Table13 1 List of locations13 that have13 been13 used to13 grow-shy‐out razorback suckers

$$amp ()amp$+ ($ampamp$+( $amp()$+ $amp()amp+(-0(12(342056( )0(-75amp8(95amp( 0$$05(lt==gt( 5amp+(amp4amp(Aamp+amp050+(12(14$6( 5amp+(amp4amp8(B$5+( B7$(lt==lt8()C0C05(lt===8(D0$05(0($(lt==E8(amp2F(0($(lt==E(

GltHI5+(342056J( K0L05(Damp$(12(342056( K0L058(D0M(0L4( N$055(lt==E( FF(-0(12(342056( D05(9$F8(B$5+( -42amp5(amp+($amp(lt==lt( OP0(0+(342056( $+05(B68(D0Q+( N-R(lt==gt( S56(Damp$(12(342056( D05(T05amp$8(N2( B7$(lt==lt8(U5Qamp(0($(lt==H8()C0C05(0($(lt==E8(0$$05(lt==gt8(N-1V-(WXXX( NQ$+0(Damp$(12(342056( NQ$+08(Y0L( N-R(lt==gt( V2M07(12(342056( M058(N2( B7$(lt==lt8(Qamp(amp+(5+M42(lt===( V$$M(042(Damp$(12(342056( 0$M(3Q05(KF(amp(B$5+(RQ058(95amp( 3ampamp(WXXgt( 942(3amp6( D05()5P058(95amp( N-1V-(lt==Z( --+-0+-12-3(4-5 )005(7amp+( 5amp+(amp4amp8(B$5+( Y2+(amp2F8(705amp$(4FFamp4amp( ltgt(5+(7amp+( 5amp+(amp4amp8(B$5+( )C0C05(0($[(WXXX( amp+(7amp+(( 5amp+(amp4amp8(B$5+( )C0C05(0($[(WXXX( B$6F05()amp+( BampC$0amp40(C(B$5+(amp+(ampampamp( )C0C05(0($[(WXXX8(B7$(lt==lt( B$5+(I(W](++amp$($00+(7amp+( 5amp+(T$$068(B$5+( )C0C05(lt===( KP0(5+(7amp+( 5amp+(T$$068(B$5+( )C0C05(0($[(WXXX( 32$amp0(7amp+( 5amp+(T$$068(B$5+( )C0C05(0($[(WXXX( 35020C(505amp(7amp+( 5amp+(amp4amp8(B$5+( )C0C05(lt===8(B7$(lt==lt( 0-6-3+ $620(Famp47$($C(450( $6208(B$C5amp( ^50amp($C(450_(9-N(R00542()5P( 08(95amp( 52(WXXH8(52(WX]( )0($C(450(7amp+( )08(95amp( 0$$05(amp+(V4P(WXX]( 768639 0amp(50(DVR( -2(C(Y4amp8(95amp( 52(WX]( B$(32(O0Q00()amp+( B$(Damp$(V$+$C0(R0C08(D05($6208(B$C5amp( 52(lt===8(amp4P$06(amp+(O55(WXXX8(0$$05(lt==gt( SQ05amp(M$+$C0(amp0F0amp(50( D05(OP0(0+(ampC$M8(D0Q+( N-R(lt==gt( -0amp5(V2( D52(C(`F8(95amp( ^5042Fampamp(amp+(O0$0(lt==gt8(amp4P$06(amp+(O55(WXXX( )1(+ KQ(4Q0( OP0(2Q08(95amp( 0$$05(WXXlt8(0$$05(amp+(5P0(lt==Z( 95amp(aQ0amp$0( OP0(2Q08(95amp( -$56(WXX]( -2(-+0Mamp+05( OP0(2Q08(95amp( -$56(WXX]( `F(BQ0( OP0(2Q08(95amp( 0$$05(WXXlt8(0$$05(amp+(5P0(lt==Z( Kamp+6( OP0(2Q08(D0Q+( -$56(WXX]( D52(B20F020Q0( OP0(2Q08(D0Q+( -$56(WXX]( D52(X($0( OP0(2Q08(D0Q+( Y6(V$05(N-R8(705amp$(4FFamp4amp( V$$M( OP0(2Q08(D0Q+( Y6(V$05(N-R8(705amp$(4FFamp4amp( D0Q+(A( OP0(2Q08(D0Q+( Y6(V$05(N-R8(705amp$(4FFamp4amp( D0Q+(O5Q0( OP0(2Q08(D0Q+( Y6(V$05(N-R8(705amp$(4FFamp4amp( 0+58lt+--457(5 9Q0(50ampampamp( D05(T05amp$8(N2( )C0C05(0($[(lt==E( ampamp(5+0( D05(T05amp$8(N2( )C0C05(0($[(lt==E( 2ampamp(F( D05(T05amp$8(N2( ++0(amp+(3amp0(lt==Z( O0(W=( D05(T05amp$8(N2( N-1V-(WXXX( O0(F( D05(T05amp$8(N2( ++0(amp+(3amp0(lt==Z( S$+(425$06(V2( D05(T05amp$8(N2( ++0(amp+(3amp0(lt==Z8(++0(WXXgt( O00+(7amp+(amp(20(Namp2(amp( D05(T05amp$8(N2( U5Qamp(0($(lt==H8()C0C05(0($(lt==E( =($+ 1$6+(OF(0(75P(GY0$0(75ampJ( O(T08(D0Q+ (52(WXXH( Y5amp++(-0(amp5(B$$00( 9$F8(B$5+( -42amp5(amp+(Oamp(lt==lt( 5MI(7amp+( D05(15Fampamp8(D( -42amp5(amp+(Oamp(lt==lt(

11

13

Table 2 Facilities available at major razorback sucker fish hatcheries

$amp( )$+(-+( 0(1(2$amp3amp(( 4-56+ amp7(8-+1$(9+( lt3-5( 8=$33( 23gt(805(

$amp()amp+(-(012345( 0(0+amp(A(BBCC(05 ampD(ED F CGBH IACCCACCC BJH K$+L(0D

amp$+(M$gt$ O-$+(+($P

B N B

CGBH IACCCACCC BABHC FANCC

BJH

Qamp+-3$+($P F FHC 637134(801amp0$(-(012345( H(L$33gt($O-amp1+(gt33A(

BCCC(05 ampDRK$+L(0D amp$+(M$gt$ M$-3$+($P Qamp+-3$+($P Qamp+-3$+($P

9O-$+amp$

SF S BC SC HC TC

CGI((IGC( HAHCC HSC IBC BCC IC

9O-$+amp$ BC SC 940amp+(amp21amp(8013(-(-02$15( U-ampamp0$3(D+ampPamp(gt$+ Qamp+-3$+($P IS VCC IB

W+Lamp1(+$+amp(0D( E-50D(+ampX+(gt$+( Qamp+-3$+($P JT BCC H K$+L(ED T CGBH(Y(CGH(

lt405(801amp0$(-(012345( J(L$33gt(gt33A(FCC(05( ampD(0D BS CGIBH(Z(CGBH( IC Qamp+-3$+($P NC IBC H Qamp+-3$+($P BJ VCC IC((IH

=$$gt(302(801amp0$(-(012345( 3$+(L$D(Q3+$D( MampX+(gt$+( amp$+(M$gt$ N IAHCC

amp$+(M$gt$ IF IFACCC 9O-$+amp$ FC IC

0$+3(801amp0$(-(012345( B([0(9O-amp1+()33A( IHCC(05 ampD(0D II I

K$+L(0D amp$+(M$gt$ amp$+(M$gt$

NJ B IB

GBH(Y(IGC( FAHCC IACCC

Qamp+-3$+($P Qamp+-3$+($P

IB N

BCC NACCC

12

13

Table13 3 Water13 quality13 ranges13 at each13 culture facility$amp ($)$++) -+$

-)amp012$)32$45 -6+)01763865 9$01-+3lt5 =amp+)01gt+39+5 $amp()amp+ ++)$6)+01A5

J gtLNL01O5 8P$ampamp401O5 ($Q+

BC3DE DD3DF BG3DB KLM3MLE KLH3MLI KLH3MLF CLM3BFLE CLM3BFLE CLM3BFLE

RQS0Aamp$ RQS0Aamp$ RQS0Aamp$ )ampQTamp$ )ampQTamp$ )ampQTamp$

8+)$O(6+T$ 8+)$ 8+)$ A6$)amp A6$)amp A6$)amp

BH3BI KLH3MLE CLM3BFLE

RQS0Aamp$ )ampQTamp$ 8+)$ A6$)amp

-01 ++)$6)+01A5 J gtLNL01O5 8P$ampamp401O5 ($Q+

BK3DE DD3DM BK3DE KLC3MLC KLC MLC DLM3GLK DLM3GLK DLM3GLK BIC3BMM BIC3BMM BIC3BMM

2ampamp$03040UQ$0amp0)6Q0amp0UampQ0ampamp0VampQ

BE3BI KLC

DLM3GLK BIC3BMM

213amp+(4amp50amp ++)$6)+01A5 J gtLNL01O5 8P$ampamp401O5 ($Q+

DH3DC DH3DC DH3DC KLK3MLE KLK3MLE KLK3MLE KLE3KLC ILC3KLE ILE3ILC BEE BEE BEE

+0$0amp+amplt+066)+0V$ampamp4S0RQ0$0)TP0T

DH3DC KLK3MLE FLC3ILC BEE

6137 ++)$6)+01A5 J gtLNL01O5 8P$ampamp401O5 ($Q+

BB3DC BB3DC BB3DC KLF3MLD KLF3MLD KLF3MLD CLE3BD CLE3KLD CLE3KLD BBG BBG BBG Aamp$ Aamp$ Aamp$

BB3DC KLF3MLD CLE3KLD BBG Aamp$

8$$9(35 ++)$6)+01A5 J gtLNL01O5 8P$ampamp401O5 ($Q+

BK3DE DE3DC BK3DE KLC3MLE KLC3MLE KLC3MLE HLE3GLE HLE3ILE HLE3GLE HEE3FEE HEE3FEE HEE3FEE RQS0Aamp$ RQS0Aamp$ RQS0Aamp$ A6$)amp A6$)amp A6$)amp 8+)$ 8+)$ 8+)$

BH3BM KLC3MLE FLE3GLE HEE3FEE RQS0Aamp$ A6$)amp 8+)$

lt3$+ ++)$6)+01A5 J gtLNL01O5 8P$ampamp401O5 ($Q+

BG3DI DI3DM BM3DM KLK3MLD KLK3MLD KLK3MLD FLE3BDLE FLE3BDLE FLE3BDLE DDI DDI DDI

A6$)amp

BF3BM KLK3MLD FLE3BDLE DDI

Bubbling Ponds State13 fish Hatchery13

Bubbling Ponds Fish Hatchery in Arizona does not maintain razorback sucker

broodstock on site Razorback suckers are received either as juveniles from13 Willow Beach

National Fish Hatchery13 or as13 newly-shy‐hatched larvae from13 Dexter13 National Fish Hatchery

Larval fish are13 typically13 placed13 into13 an unfertilized unlined 0613 acre13 pond13 in the13 spring In

September the pond is harvested by draining the pond and seining All fish that have

reached the target size (300 mm TL) are stocked Fish that are too small to stock are split

up equally between the six remaining grow-shy‐out pond at an13 average13 density13 of about 5000

ndash 7000 fish per pond Fish are fed by hand at approximately 25 body weight split

between morning and evening feedings Fish are either fed a catfish diet made by Rangenreg

13

13

that is enriched with spirulina and krill or razorback sucker diet made by Silvercupreg

depending on availability Fish are monitored visually and by sampling using a cast net

When a large number13 of fish have13 grown to13 the13 target size they13 are13 harvested13 by13 draining

the pond and seining13 Fish are again13 sorted by hand and the largest13 fish are stocked13 Fish

that13 have not13 reached the target13 size are returned to the ponds for further grow-shy‐out13 On13

average it13 takes one to two years for fish to reach the target13 size with fish growing13 an

average of 06 mmday Target numbers for production are 12000 razorback suckers

annually (300 mm TL) The biggest difficulty in rearing razorback suckers at Bubbling

Ponds13 Fish Hatchery13 is protozoan13 parasite13 infestations13 (Ich) and13 associated13 bacterial

infections that come from13 an open spring source that is inhabited by mosquitofish

Dexter National Fish Hatchery13

Dexter National Fish Hatchery maintains four separate razorback sucker13

broodstocks13 These fish are spawned on13 site and larval13 fish are placed directly into 01 acre

ponds at a density13 of about 20000 larvae13 per pond (50 ndash 100 thousand13 per13 acre)13 Ponds

are fertilized with alfalfa13 pellets and superphosphate two weeks prior to receiving13 larvae to

produce13 natural13 feed for larval13 fish13 Ponds are13 fertilized again with alfalfa13 pellets one week

after larvae are introduced13 Fish are fed a catfish starter diet13 (sizes 1-shy‐3) made by Rangenreg

that13 is enhanced with spirulina13 and krill13 and then switched over to the razorback13 diet13 once

they are large enough to eat 1mm13 crumble Fish are fed twice a day by hand four days a

week13 at 25-shy‐60 body weight Feed ration is decreased if excess feed is seen remaining

on the13 pond bottom13 following feedings Fish are not graded or sorted during this grow-shy‐out

period Razorback suckers are harvested in the fall by draining ponds completely Fish are

sorted13 at harvest and13 distributed13 to13 other13 facilities13 for further13 grow-shy‐out depending on13

current size requirements Razorback suckers are on average 100 ndash 200 mm TL after the

first growing13 season13 and13 generally13 take13 1 -shy‐18 months for a majority of the fish to reach

300 mm TL There are 16 different species of fish maintained at Dexter National13 Fish13

Hatchery13 and13 having sufficient pond13 space13 to13 grow out separate13 groups13 of fish is the13

limiting factor for production of razorback suckers at this location

14

13

Grand Valley13 Native13 Fish Facility13

The Grand Valley Native Fish Facility maintains its own brood stock13 in13 eight13 ponds

located at the Horsethief Basin Wildlife Area in Grand Junction Colorado Fish are

spawned13 on site13 and13 larvae13 are13 reared13 indoors in fiberglass13 tanks13 at the13 24-shy‐Road13 Fish13

Hatchery13 in Grand13 Junction The 24-shy‐Road13 Hatchery13 consists of two13 separate13 recirculating13

systems that operate using de-shy‐chlorinated13 city13 water13 and two13 large13 fluidized-shy‐ bed sand

filters13 and13 rotating-shy‐drum13 filters for waste removal Fish are held in 4-shy‐foot (n=78) or 8-shy‐foot

(n=14) diameter fiberglass tanks Larval fish are started on prepared feeds immediately

after swim-shy‐up and fed exclusively razorback feeds made by Silvercupreg Fish are started on

a 0-shy‐250 micron razorback diet for the first 10-shy‐1213 days13 and13 then13 fed with13 gradually13

increasing13 feed sizes based13 on observations of feeding13 (250 ndash 400 micron 1 starter) Feed

sizes are mixed when transitioning to the next larger feed size These razorback diets are

specially sifted by Dr Rick Barrows (USDA13 Hagerman experiment station Idaho)

Razorbacks13 are13 typically eating 1mm13 extruded pellets by the time they are 35 to 4 inches

in length Fish are fed approximately 70 body weight per day initially and then gradually

reduced to 15 body weight by the time they reach the 300 mm TL target size Fish are

fed seven days13 a week using13 12-shy‐hr13 belt feeders It takes13 12-shy‐16 months to grow fish to the

target13 size in13 the hatchery13

Razorback suckers are sorted after three months and culled to about 4000 fish per

family lot Culled fish are stocked into leased grow-shy‐out ponds Stocking densities for

juveniles in these ponds is based on previous13 stocking and harvest13 rates13 and is pond

specific13 Grow-shy‐out ponds are13 harvested13 periodically13 using Fyke13 nets13 or trap13 nets13 and13 fish of

the target size are stocked Disease problems (Ich Lernea) water quality problems (low

DO) and difficulty in removing all of the fish are challenges for grow-shy‐out of razorback

suckers13 in these13 natural ponds13

Fish reared13 in the13 24-shy‐Road facility are sorted again at four to five months of age into

small and large size groups to obtain more uniform13 growth rates Batch estimates of fish

weight are done every month for each tank A group of fish are weighed and counted to

give an average weight for the tank with lengths estimated based on a lengthweight chart13

The biggest difficulties13 for growing13 out razorback suckers13 at the13 24-shy‐Road13 Fish13 Hatchery13 are13

insufficient space and water flow (oxygen) to grow fish to the target size At the Horsethief

15

13

Basin13 Ponds where broodstock13 are reared13 diseases such as Ich are problematic because

water is pumped directly from13 the Colorado River

Ouray13 National Fish Hatchery13

Ouray13 National13 Fish Hatchery maintains its own broodstock and13 spawns13 fish on-shy‐site13

Larvae are transferred from13 indoor hatching tanks to unfertilized 02 acre outdoor ponds

and stocked at densities 10000 ndash 20000 larvae13 per13 pond13 Even13 though13 outdoor13 ponds13 are13

covered with13 bird13 netting13 avian predators13 still get caught in the13 nets13 if they13 can see fish

Ponds are dyed blue13 as the13 fish grow to13 prevent avian predation13 While in the outdoor

ponds13 fish13 are13 fed a slow-shy‐sinking salmon diet made by Silvercupreg twice daily by hand

Amount of feed is based on periodic sample counts Fish are grown until late September at

which time temperatures require that all fish13 other13 than13 adult broodstock13 be13 brought

inside for the winter Ponds are drained completely and fish are sorted by hand Fish that

have reached the target size (300 mm TL) are stocked into the Green and Colorado Rivers

All remaining fish are moved indoors13 and13 held13 in three-shy‐foot (n= 30) or eight-shy‐foot (n=27)

diameter circular tanks On average it takes 12 ndash 18 months to grow fish to the 300 mm TL

at Ouray13 hatchery13

Razorback suckers are held during the winter in a recirculating system13 that

operates13 using13 two13 large13 fluidized-shy‐bed sand filters and a rotating-shy‐drum13 filter for solids

removal Fish are fed the Silvercupreg razorback diet using belt feeders There is currently

capacity13 to13 hold13 only13 20000 200-shy‐300 mm TL fish inside the facility and any extra fish13 are13

stocked13 into13 floodplain-shy‐wetlands or used for research purposes13 Ouray no longer leases

any private grow-shy‐out ponds Grow-shy‐out ponds were troublesome due to poor water quality

harvesting13 difficulties13 and13 non-shy‐native13 fish introductions13 The biggest difficulty13 for

production13 of razorback13 suckers at the Ouray13 National13 Fish13 Hatchery13 is space13 during13 the

winter to maintain large numbers of fish and high iron and manganese in the well water

that must be filtered out prior to use

16

13

Willow Beach National Fish Hatchery13

Willow13 Beach National13 Fish Hatchery receives wild-shy‐caught larvae from13 Lake

Mohave Larvae are treated for diseases with formalin and malachite green and placed in

45 ten-shy‐gallon13 flow-shy‐through aquaria13 Recirculated13 solar heated water13 22-shy‐25deg C is used to13

allow production of warm13 water fish at this traditionally cold water facility (Figiel 2003

Figiel et al 2005) Fish are fed brine shrimp nauplii to satiation every hour and after 14

days small amounts of specialized larval fish diet (Encapsulon13 Cyclopeeze13 spirulina13 and

artificial plankton) are introduced After 30-shy‐6013 days13 fish are13 transferred13 to13 six13 32-shy‐gallon13

fiberglass troughs at densities of 1000 to 1500 fish per tank and then a month later moved

outside13 to13 eight recirculating13 raceways that use a combination of well water and solar-shy‐

heated water to maintain temperatures of 22 ndash 25deg C during the summer months

When13 in13 the outside raceways13 fish are fed the razorback13 diet13 using13 belt13 feeders and

fed by13 hand13 at 10 -shy‐ 70 body13 weight per13 day Feed amount is adjusted based on sample

counts according to a feed conversion program13 developed for razorback suckers by Willow

Beach Hatchery personnel This program13 uses length and number-shy‐per-shy‐pound generated

from13 several years of razorback growth data (Figure13 1) Fish are13 sorted13 opportunistically13

and are not handled during the summer months when water temperatures are above 20degC

In 2004 the target size for stocking was 325 mm TL or greater (WBNFH 2004) with a

target13 of producing13 6000 fish per year Reaching this13 target size usually13 takes13 two13 growing13

seasons13 The biggest difficulty13 in rearing13 razorback suckers13 at Willow Beach13 National Fish

Hatchery13 is insufficient space13 to13 grow fish to13 increased13 target sizes (400-shy‐500 mm TL)

Uvalde13 National Fish Hatchery13

Uvalde13 National Fish Hatchery13 in Texas13 receives 35000 ndash 60000 razorback sucker13

fry annually in MarchApril from13 Dexter National Fish Hatchery The fry are acclimated in

bags submerged in the pond for a minimum13 of one hour and released into13 a 1 acre13 fertilized13

pond where they are reared for the remainder of the summer Fingerlings are fed a starter

razorback diet when they reach approximately 50 mm TL In AprilMay the previous year

class of razorbacks are captured from13 their over-shy‐wintering pond enumerated graded and

split into13 one-shy‐acre grow-shy‐out ponds Approximately 4000 ndash 5000 fish will be13 placed13 in each13

one acre pond for summer grow-shy‐out Fish are reared for approximately 150 days (May ndash

17

13

Oct) and fed the Bozeman razorback diet two times a day five days a week at 15 ndash 30

body weight per day based on average water temperature

Figure 1 Relationship between length and number of fish per pound

In general13 juvenile razorback13 suckers (received as fry13 during13 the previous spring)13

reach the target size of 300 mm TL in approximately 6 months In 20062007 Uvalde

produced 6000 razorback suckers 300 mm TL for introduction into the San Juan River

Starting13 in 2008 Uvalde NFH will be producing13 and distributing13 12000-shy‐ 300 mm TL

razorbacks for stocking into the San Juan River Predation from13 migrating cormorants has

occurred but timing of harvest and over wintering protection methods such as covering

ponds with netting or placing fish indoors helps to minimize losses during the cormorant

migration (November to March) Uvalde has experienced razorback mortalities because of

bacterial problems but these are usually resolved through the use of oxytetracyline

medicated feed

Overview13 of Differences in Culture Methods

Several differences were noted when conducting surveys at each of the five main

production facilities for razorback sucker (See Appendix 3) These differences include

different stocking13 and13 rearing13 densities13 (Table13 4-shy‐5) various feeding regimes and type of

18

13

lt=amp

feeds (Table 7) as well as differences in grading or sorting practices Some of these

differences are13 related13 to13 whether13 or not razorback suckers13 are13 being13 reared13 in extensive-shy‐

culture13 facilities13 (ponds) or intensive-shy‐culture13 settings13 (raceways13 o tanks)13 Some13 practices13

are unique to a single facility13 or a couple of facilities (Table 6)13 Managers at each facility13

were asked to identify the biggest13 difficulty or constraint13 that13 they experience when13

growing-shy‐out juvenile13 razorback suckers13 at their13 respective13 location13 Space constraints13

water quality and disease problems were the main factors limiting production of razorback

suckers13 at these13 facilities13 (Table13 8) Calculated or reported growth rates from13 the literature

vary widely (Table 9) and range from13 02 to 18 mmday These growth rates indicate that

juvenile razorback suckers have a very high growth potential under optimal rearing

conditions13

Table13 4 Stocking13 densities13 for larvae13 and13 fry in ponds

$amp( )(+amp-( 01-2(3(4amp56( 4amp56(+amp-( 01-2782-( $amp () + --amp +amp0amp)+amp 12-3amp ( )+amp0amp+amp --amp +amp0amp)+amp 42556789amp8 ( +amp0ampgt+amp 3amp +amp0amp+amp A-BC-Damp (E + 3amp )+ F-6ltamp ) G+ 3amp G+

Table13 5 Rearing13 densities13 at intensive13 culture13 facilities13

$amp( )amp+(($-( $0( 12(3$+( 40((amp05( 67((amp05( 8$9(407$( $amp amp())amp++-$amp 0 1 0amp2amp1amp 3amp2amp4 0544

6amp())amp++-$amp 610 021 4amp2amp47amp 3amp2amp77amp 058 9$amplt+)amp 4amp())amp++-$amp 00 1 7amp2amp77amp 851amp2amp0amp 05

6amp())amp++-$amp 610 77amp2amp1amp 0amp2amp1amp 053

19

13

Table13 6 Rearing13 practices13 that are13 unique to13 specific rearing13 facilities13 $$amp( )$+-(amp$-(0(1-amp2034( $amp()amp+( -0$(12(33+(amp(amp134$53+(amp$amp3+(6amp+(

723(843(1$8(422(6amp+(42amp(4(423(19$43( 343( lt34$53(6amp+(6(4($03(amp4+94amp(842($1$1(63$$34(amp+(63626243( =amp+(gtamp94ampA( B3(1(1$+53+C3+(amp+(1$43(1(3D0$(1(amp443(amp+(amp443( 734231(amp( B3(1(193(44(1(34amp(amp(+49E(6amp+( -E3(F3+( G3amp(1(12(amp(H3(13$(4ampE(C(IJK($$amp( A( L43(+A3(4(6303amp4(63+4ampM(66$3D3amp4$(34amp(amp(6amp+(C((4amp3( L$$8(392(

B0$+3(

N43D(13+(4($0$(12M(amp+(639$53+($0$(12(+34( G3amp(12(amp(399$4amp(4+(938A(842($(2343+(843( N443D643+(3amp(12(amp(amp34(63amp(amp(423(O$+(G03( )amp+(3(134$53+(6(4(39364(1(1A(4(44(423D(amp((D3(amp4$(+34(

Table13 7 Types of feed used at razorback sucker13 hatcheries13 $amp ()amp+-amp0- $$)1amp23 45-amp)-$5)1amp23 $amp()amp+( -amp$amp+(amp+( -amp012$3+(amp+4(amp5215$(0+( 65ampamp7(85209(+2($1(87((15315lt=(+2(

+amp+amp(amp(55$5$2gt( 21( Aamp+(amp+( )amp+(012$3+(B29(5$05$95($$2(5amp+(

199524(amp5215$(0+( 65ampamp7(85209(+2($1(87(15315lt=(+2(amplt( 29gt(51($51(amp9(2(25=(C(DD(0+(

E15amp+(Famplt2amp( G1$5(lt1lt$51(25amp=( HIJKH(Dlt1amp(15315lt=(+2(I(C2(CH(+5gt( )11$gt($511(02+(15315lt=(+2(

$1(87(15315lt=(+2(D5$$(3(lt5$$gt(02+(gt( 6lt=(511B(

L15gt( G1$5(lt1lt$51(25amp=(Aamp+( amp+(

HIJKH(Dlt1amp(15315lt=(+2(I(C2(CH(+5gt( )11$gt($511(02+(15315lt=(+2(

$1(87(15315lt=(+2($1(87($B(amp=amp( 5$Damp(+2(

M$$B(5lt9(-5$+( NO515(G1$5(219( L2+1(15ltB5gt(Aamp+(5amp+( amp$amp+(amp+(

1amp(91D(amp5$(Pamplt5$amp4( 8gtlt$34(1$amp54(5amp+(5120lt5$( $5amp=2amp()amp+(012$3+(B29(5$05$95( $$2(5amp+(19952Q(amp12152( 1+lt2amp(

$1(87(15315lt=(+2($1(87(15315lt=(+2( $1(87(15315lt=(+2(

Table 8 Factors limiting production at major razorback sucker facilities

$amp( )amp+(-0+1((2$(0amp1ampamp(-34amp( $amp()amp+( -(01$2(34+(546(amp(0amp(01amp(541(13( -741( 803(3amp41amp4(9((+ltlt1amp4(03(amp(44amp(2=(4(

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20

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Table9Reportedandcalculatedgrowthratesfromtheliterature

Calculatedgrow

thratesbasedon

informationprovidedinliterature

aApproximationsofmaximum

grow

thpotential(basedon

average13 maximum

sizesiffishreportedatharvest

21

13

General Information on Factors that Affect Fish Growth

Growth in fish is extremely variable and is impacted by many different

physiological and environmental factors Growth rates are known to change with size and

age sex season activity level density amount13 of living space quality and quantity of food

genetics and temperature (Brett 1979) Growth experiments conducted at different times

of year can result in growth rates that are not comparable As fish become larger their

physiological13 potential to grow decreases making determination of growth rate dependent

on the size of the starting fish and the length of the experiment (Busacker et al 1990)

Genetic factors also have great potential to influence growth rate Some species have

strains13 and13 races13 that display vastly different growth potentials (Reinitz et al 1979) All of

these factors combine to make assessment of the individual factors controlling fish growth

difficult13

Water temperature is probably the most important variable affecting growth rate13

All of the basic functions that affect growth such as feeding digestion and metabolism are

temperature-shy‐dependent13 Growth13 is inseparably13 tied13 to13 bioenergetics13 and13 therefore13 also13

tightly tied to temperature When temperatures are below optimum daily temperature

fluctuations can stimulate growth Photoperiod is also commonly linked to water

temperature and can influence growth rates in fish (reviewed in Brett 1979)

Fish density13 is known to13 affect growth13 and13 can alter13 growth13 rates13 in several ways13

Fish that exhibit strong territorial behaviors13 or natural schooling tendencies13 will

experience reduced growth if densities are too high or too low (Brett 1979) Dominance

hierarchies where some fish feed more aggressively than others can also lead to high

variability13 in growth13 rates13 (Koebele13 1985) Crowded13 conditions13 also13 cause physical

interference13 between13 fish and13 poor water13 quality13 which13 reduces13 growth13 (Busacker13 et al13

1990) The effects of fish numbers space and feeding opportunity are frequently correlated13

and often13 difficult13 to distinguish (Brett13 1979)13

It is impossible to study the effects of environmental factors on growth without also

evaluating feed rations (Brett 1979) Amount of food quality of the diet particle size

number of feedings per day and time of feeding have all been shown to affect growth

(Busacker et al 1990) In controlled laboratory studies food is usually fed ad libitum13

22

13

(constantly available) and other variables are altered to assess impacts of environmental

factors13 on growth13 These studies13 are13 usually13 conducted13 in tanks13 or raceways13 because13

researchers must verify that food is constantly available to the fish which is difficult to do

in large pond environments where the fish and the bottom13 are often not visible (Busacker13

et al13 1990)

Specific Information13 o Razorback13 Sucker13 Growth

Variable13 growth

Growth in razorback suckers is naturally highly variable and may be a function of

their evolutionary history (USFWS13 2002)13 Minckley (1983) speculated that13 wide size

variation in a single cohort of razorback suckers may be adaptive with fast-shy‐growing13 fish

that13 reproduce at a young13 age surviving13 better in13 high discharge years and slow-shy‐growing13

smaller fish surviving better during drought periods This highly variable growth rate

makes rearing razorback suckers in a production setting difficult because fish from13 a single

cohort do not reach the target stocking size simultaneously One of the major tasks for

aquaculture is to maximize both individual growth and total production13 (Gerking13 1978)13

This becomes more difficult when the species being cultured exhibits highly variable

growth13 rates13 because of genetic influences as is the case with razorback13 suckers13

Razorback13 sucker growth13 is typically very13 rapid13 during13 the first13 year of life13 and then13

declines with age First year growth can be as low as 50 mm and as high as 350 mm (Valdez

et al13 1982 Minckley13 1983 Mueller13 1995) Razorback sucker13 grow rapidly13 for

approximately the first five or six years of life and then growth slows13 (McCarthy13 and13

Minckely 198713 Tyus 199813 Minckley et13 al 1991)13 Growth of older individuals in13 extant13 wild

populations is very13 low (Minckley 198313 Tyus 198813 Modde13 et al 1996)13 Wild growth13 rates

for mature adult fish in Lake Mohave based on PIT tag recaptures were often too small to

be accurately measured for both males and females over the time period of 1987-shy‐199713

(Marsh and Pacey 1998) This information suggest it will take substantially longer to rear

fish to13 increasingly13 larger13 stocking13 sizes (40013 ndash 500 mm TL) than it did to reach the target

size of 300 mm TL

Growth in ponds

23

13

One of the main strategies for maintaining genetic refugia and self-shy‐sustaining13

populations of razorback13 sucker in the lower Colorado13 River basin13 is to rear razorback13

sucker13 larvae13 in production13 ponds until they13 are13 a suitable13 size for stocking13 (USFWS13 2004)

Pond culture has proven useful to promote rapid growth of juvenile razorback suckers

(Kaeding and Osmundson 1989) Marsh (1994) reported that growth rates of razorback

suckers13 reared13 in golf-shy‐course13 ponds exceeded13 the13 best growth13 rates13 obtained13 under

intensive13 culture13 conditions13 at federal hatcheries13 especially13 during the13 first several years13

of life Growth rates in these semi-shy‐natural ponds are also comparable to estimated growth

rates13 of juvenile13 wild13 fish (McCarthy13 and13 Minckley13 1987) Modde13 and13 Haines13 (2005)

reported13 the13 greatest growth13 rates13 in the13 largest and13 deepest floodplains13 with13 the13 greatest

amount of submergent vegetation but excellent growth and survival of fish in a grow-shy‐out

pond is of little value if there is not an efficient way to collect the fish from13 the pond

(Kaeding and Osmundson 1989)

Temperature13

Bulkley and Pimentel (1983) used shuttle boxes in the laboratory to determine a

temperature preference13 for razorback suckers13 of 23-shy‐24degC13 In13 their13 studies13 razorback

suckers were found to avoid temperatures below 118 degC or above 286 degC Razorback

suckers at Bubbling Ponds Hatchery are more active in the spring and feed better as

photoperiod increases even prior to water temperatures rising (Frank Agygos personal

communication) Table 3 briefly summarizes water temperature data from13 each facility

Detailed seasonal water temperature profiles are not currently available for many

razorback grow-shy‐out sites13

Density13

Extensive studies have been conducted on commercially important species to

evaluate stocking densities and feeding rates that maximize production For these species

controlled experiments under laboratory conditions have established relationships

between temperature density and feed ration on growth (Brett 1979) but this information

is sporadic13 or non-shy‐existent for razorback suckers13 (Bays13 et al13 2005) Fish culturists13 with13

24

13

experience13 rearing13 razorback suckers13 typically13 have13 target stocking13 densities13 that13 they use

(Tables13 4 -shy‐ 5) These stocking densities have largely been determined over time by trial

and error These approximate stocking densities provide a good starting point for more

controlled13 types13 of replicated13 pond studies13

Feed ration

Razorback13 suckers are currently13 being13 fed a wide variety13 of prepared diets (Table 7)

that range from13 a slow-shy‐sinking salmon feed manufactured by Silver Cupreg to a spirulina

and krill-shy‐enhanced catfish feed made by Rangenreg Most locations are feeding 20 ndash 50

body13 weight per13 day13 Methods13 for culture13 of razorback sucker13 larvae13 in intensive13 settings13 at

fish hatcheries are well documented (Figiel 2005) and various larval fish diets have been

evaluated13 (Tyus and13 Severson 1990 Severson et al13 1992) but no standardized13 procedures

are used for feeding13 larval13 fish in13 intensive settings13

Razorback sucker larvae are also effectively reared in pond environments using

natural foods supplemented with larval fish diets and survival is high when no predators

are present13 (Mueller 2006)13 Growth rates for larval13 and early juvenile razorback13 suckers

may increase with pond fertilization Diet and physiological studies on wild razorback

suckers indicate that they feed on plankton as well as benthic organisms during their entire

life (Marsh 1987) Artificially fertilizing ponds may greatly increase production capacity

and growth rates for razorback13 sucker (Papoulias and Minckley13 1992) and warrants

further13 investigation13

Handling stress

Handling stress13 has13 been shown to13 influence growth13 rates13 Paukert13 et al (2005)

found that growth of bonytail chub was reduced by 26when compared with controls

after being13 repeatedly13 captured and handled in13 hoop13 nets13 Handling13 effects are likely13 to be

similar for razorback suckers that are repeatedly13 captured and sorted in13 a hatchery13 setting13

Razorback suckers that are handled at Willow Beach National Fish Hatchery will commonly

not eat for two weeks after handling (John Scott personal communication) This creates a

difficult situation13 for production13 facilities because13 fish13 need to be sorted to ensure13 large13

25

13

aggressive fish do not interfere with growth of smaller individuals but frequent handling

and sorting13 causes stress related reductions in13 growth13

Measuring Growth in Captive Fish

Weight is the traditional measure used to estimate growth or production in

aquaculture settings13 Groups of fish are typically13 weighed and an average individual13 weight13

is computed (Busacker et al 1990) Although this method is often logistically the easiest it

may not be the most informative for species with highly variable growth rates like

razorback suckers especially when target lengths must be reached before fish can be

stocked Weight can also be highly influenced by things like stomach fullness or

development of gonads (Busacker et al 1990) Condition factor or relative weight can also

be used to assess growth of fish but these tools may be more robust predictors of fecundity

than of growth (Anderson and Neuman 1996) For some species sexes need to be

distinguished because males and females may differ in morphology (Anderson and

Neumann 1996) Mueller (2006) analyzed growth rates based on PIT tag recaptures of 86

razorback suckers13 in High13 Levee Pond13 and13 found13 that differences13 in growth13 do not appear13

to occur until fish are over 450 mm TL at which time growth rate in males slows while

females continue to grow at a slightly higher rate This would indicate that sex may not be

an important factor to consider when examining growth rates unless the target grow-shy‐out

size is above 450 mm TL

The best measures of growth are often determined from13 the length and weight of

individuals rather than from13 groups of fish (Anderson and Nuemannn 1996) because

individual growth rates give better estimates of confidence and variance (Busacker et13 al

1990) Length frequency analysis or recapture of previously marked individuals of a known

size is likely to yield the most useful information for razorback sucker growth The success

of any of these methods depends on proper sampling procedures that are representative of

the population as a whole (Busacker et al 1990) Sampling methods that are known to be

size-shy‐biased such as trammel nets (Mueller et al 2004) or cast nets should not be used when

trying to measure growth rates13

26

13

Conclusions

For razorback sucker survival is largely associated with stocking size Additional

focused13 research13 is therefore13 needed to13 identify13 ways13 to13 increase13 growth13 rates13 of captive-shy‐

reared13 razorback sucker Growth13 rate13 in fish is controlled13 by many factors including fish

size and age temperature density and feed ration which can all be highly correlated

Growth of razorback suckers is also inherently variable which makes the task of identifying

the key factors that13 affect13 growth in13 captivity even more difficult The focus at most

razorback rearing facilities13 is production so the13 types13 of data that are13 collected13 are13 often

insufficient for detailed13 evaluations13 of individual rearing13 practices13 on growth13 Surveys of

existing13 razorback sucker13 rearing facilities indicate that culture methods vary widely and

the types of growth data13 that13 are collected are not13 standardized13 Replicated studies with

detailed information on rearing location water temperature initial stocking size stocking

density and the sizes of all fish at harvest are needed in order to compare the effects of

individual rearing practices on growth This type of research will ultimately provide both

time and cost-shy‐savings to production facilities by reducing the amount of time necessary13 for

razorback sucker to reach stocking size improving overall production efficiency

Optimum13 rearing densities for razorback sucker larvae and juveniles remain to be

determined Current stocking densities will be very useful as starting point for more

detailed studies and although optimum13 rearing densities are likely to be site-shy‐specific13

replicated studies on density will provide a valuable reference for hatchery managers

Frequency13 of sorting is another13 area that needs13 further13 research Frequent

handling13 and13 sorting13 can13 cause13 stress-shy‐related13 reductions13 in growth but not sorting can

create dominance hierarchies that further reduce growth rates of subordinate individuals

The effects13 of sorting13 on overall fish growth13 in both13 pond and13 intensive13 culture13

environments warrant further investigation Research techniques for these types of

experiments are well understood and typically utilize a matrix of replicate ponds per

variable (Bays et al 2005) In every case accurate and complete records of sampling

procedures and data collection are needed in order to interpret data and make inferences

about13 growth rates (Busacker et13 al 1990)13

27

13

Additional research is also needed to evaluate long-shy‐term13 survival of stocked fish

reared in ponds compared to fish13 reared13 in intensive13 culture13 facilities13 Exercise13

conditioning13 and predator-shy‐recognition training may also increase survival of stocked fish

and be more economically feasible than rearing fish to increasingly larger sizes prior to

stocking13 The success13 of traditional fish hatchery programs is measured largely by the

number of fish stocked but hatchery programs for endangered species must measure

success in terms of long-shy‐term13 survival and species recovery (Brannon 1993 Anders 1998)

A specific list of research recommendations follows

Specific Research13 Recommendations13

bull Use replicated studies13 to establish optimum stocking13 densities13 for ponds13 and

tanks13 that can be used as13 a starting13 point for site specific refinement

bull Determine if sortinggrading13 improves13 overall growth rates13 in both ponds13 and

intensive culture facilities13

bull Investigate the use of artificial fertilizers13 to improve growth of both juvenile

and adult razorback suckers13 in ponds13

bull Determine if the razorback sucker diet gives13 better growth rates13 than cheaper

catfish or salmon feeds

bull Evaluate growth rates13 and production potential of new intensive culture

methods13 such as13 large circular tanks13

bull Evaluate13 long-shy‐term survival of fish produced from raceways13 and circular tanks13

compared to fish reared in ponds13

bull Evaluate more effective means13 of treating13 fish diseases13

bull Evaluate factors13 other than size that may increase post-shy‐stocking13 survival such

as13 exercise conditioning13 predator recognition training or rearing13 under more

natural settings13

28

13

II The Effect of Disease Treatments on Razorback Sucker

Growth

Section13 SummaryFormalin copper sulfate potassium permanganate and13 salt are all chemicals commonly13 used13 to13 treat13 Ichthyophthirius multifiliis outbreaks in captive razorback sucker (Xyrauchen13 texanus) Weexposed 190 juvenile13 razorback suckers (127 ndash 26 mm TL) to13 5 5-shy‐day treatments with13 each13 chemical to evaluate the effects13 these chemicals13 may have on growth Fish grew an average of23513 mm TL13 during the month13 study period Fish treated with formalin grew on average13 29mm TL (03 mmday) while fish treated with copper had the lowest growth averaging 20 mmTL (021 mmday) No significant differences in13 growth were observed among fish treatedwith any of the chemicals compared to untreated fish (pgt005) Reductions in growth13 as aresult of repeated chemical treatments are not likely the cause of differences in growth ratesamong13 facilities that raise razorback suckers Repeated chemical treatments may13 have otherimpacts to overall13 fitness or long-shy‐term survival but13 these effects were not13 evident13 in our study

29

13

Introduction

Preservation13 of razorback sucker13 (Xyrauchen texanus) currently13 depends on captive13

rearing and stocking programs until permanent solutions to factors that prevent wild13

recruitment are found Low survival of stocked razorback suckers (Brooks 1986 Marsh

and Brooks 198913 Marsh and Pacey13 2005) has caused target13 sizes for stocked fish to

steadily increase in efforts to reduce predation mortality (Marsh et al 2005 Schooley and

Marsh 2007) Rearing fish to larger sizes at hatcheries comes with increased costs and

creates the need to evaluate husbandry and rearing practices that may affect fish growth

Formalin copper sulfate potassium13 permanganate and salt are all chemicals

commonly used at razorback sucker rearing facilities to treat outbreaks of the protozoan

parasite13 Ichthyophthirius multifiliis ldquoIchrdquo is one of the most pathenogenic diseases of

cultured13 freshwater13 fishes (Matthews13 2005) and causes large13 losses in captive13 populations13

of endangered razorback sucker Each of these chemicals used to treat Ich only kill the free-shy‐

swimming life stage of the parasite13 requiring13 repeated doses over several13 days depending13

on water temperature These chemicals treatments are needed to prevent loss as a result

of disease outbreaks but the cumulative effects repeated disease treatments have on

growth13 are13 unknown

Copper13 sulfate13 has13 been shown to13 significantly13 reduce13 growth13 of channel catfish13 in

production13 ponds (Rabago-shy‐Castro13 2006) but it is unknown whether13 razorback suckers13

experience similar reduced growth following copper treatment Quantifying the impacts of

disease treatments on growth will help to interpret the wide differences in growth rates

observed13 at various13 razorback sucker13 production13 facilities13 throughout the13 southwest

(Ward et al 2007) If one chemical is found to have less detrimental impacts on growth

than another then it may be preferred for use as a disease treatment We evaluated growth

rates13 of razorback suckers13 under13 replicated13 and13 controlled13 conditions13 to13 assess13 effects13 of

repeated formalin copper sulfate and potassium permanganate and salt treatments on

growth13

Methods

We captured 190 juvenile razorback suckers from13 ponds at Bubbling Ponds Fish

Hatchery AZ using hoop nets or cast nets All fish were of the same age class and

30

13

averaged 179 mm total length (TL) (range13 = 127 ndash 262 mm TL)13 These fish were13 offspring13

of captive13 razorback sucker13 broodstock held13 at Dexter13 National13 Fish Hatchery13 NM13 (2007

year class) All fish were tagged with passive integrated transponder (PIT) tags and

quarantined for one month prior to the experiment to allow fish to recover from13 tagging

and become accustomed to being held in circular tanks

At the beginning of the study all fish were weighed measured and scanned for

individual tag numbers with 19 randomly selected fish placed into each13 of 10 8-shy‐foot

diameter circular tanks (Figure 2)13 Each13 tank contained13 two13 airstones13 and13 an13 individual

biofilter with a recirculating water pump (31 litersminute) that had been operating for

at least 1 month prior to the experiment to allow bacterial colonies to become

established Two tanks were designated as a control and did not receive any chemical

treatments while the other eight tanks received formalin copper sulfate potassium13

permanganate or salt treatments at two week intervals (two tanks per chemical

treatment) Formalin copper sulfate and potassium13 permanganate were treated at 1 part

per million (ppm) and salt was applied at 30 parts per thousand (ppt) These treatment

rates are commonly used to treat13 razorback13 suckers for ich at Bubbling13 Ponds Fish13

hatchery (Frank Agygos personal communication)

Figure 213 Photo ofexperimental tankswith individualbiofilters and aeration

31

13

Each treatment consisted of a series of doses applied on Wednesday Thursday and

Friday with a 90water change between each dose Biofilters were removed from13 all

tanks and held in a separate holding facility during treatments and then replaced on the

Monday following treatments after a 90water change This schedule allowed fish to be

exposed to chemical treatments for 5 consecutive days without water quality deteriorating

This 5-shy‐day chemical treatment was repeated every two weeks from13 July to October (97

days)13 for a total of 5 5-shy‐day treatments Water temperature in the treatment tanks ranged

from13 13degC (55degF) to 32degC (91degF)

Fish were fed a fixed ration of commercial razorback diet (Silvercup 4mm13 pellet)

once daily13 (2 percent body13 weight per day13 as calculated13 by13 average initial fish weight)13

At the end of the experiment all fish were again weighed measured and scanned for

individual tag numbers Growth of fish in each treatment group was compared using

analysis of variance (ANOVA) Any mortalities13 that occurred during the13 study13 were13

replaced with previously quarantined fish of equivalent size to maintain equal densities in

each13 tank13 but growth13 data was13 only13 recorded for fish which13 survived13 the13 entire13

experiment

Results

Fish at the13 start of the experiment averaged 179 mm TL (Range13 = 127 ndash 262 mm)

with no significant differences in fish length among treatment groups (F(4189) = 00183 p

gt 0999 ANOVA) On average fish grew 235 mm TL (024 mmday) during the 3 month

study13 Fish in tanks13 treated with formalin had the highest growth averaging 29 mm TL (03

mmday) while fish in tanks treated with copper had the lowest growth averaging 20 mm

TL (021 mmday) Fish in the control tanks averaged 213 mm TL in growth (022

mmday) (Figure13 3)13 Formalin-shy‐treated fish grew13 significantly faster than13 any other

treatment group but no13 significant differences in growth13 in length13 or weight were13

observed among fish treated with any of the chemicals compared to untreated (control)

fish (pgt005 ANOVA)

32

13

Figure 313 Average growthof razorback suckersexposed to a series of 5 5-shy‐day chemical treatmentsover a 97-shy‐day13 periodError bars representstandard error

Discussion13

Growth13 rates13 observed13 in our study13 (021 ndash 03 mmday) are low compared to those

reported13 in other13 studies13 of razorback sucker13 growth13 (0213 ndash 18 mmday) (Ward et al

2007) Using recirculating water systems for our study required filters to be removed and

replaced during treatments Stress to fish caused by removing and replacing filters within

the tanks as well as repeated water changes may have led to overall higher stress and

reduced growth rates compared to those reported for unconfined fish Growth in fish is

highly variable and is affected by many different physiological and environmental factors

including fish size density temperature amount of space and food (Brett 1979) We

strived to control each of these factors but other factors may have also influenced growth

in our experimental tanks During mid-shy‐summer water temperatures in the treatment

tanks reached 32degC (91degF) At these warm13 temperatures fish are very susceptible to

bacterial13 infections13 The slightly higher growth exhibited by fish in the formalin and

potassium13 permanganate treatments may have been the result of these two chemicals

33

13

being effective at controlling bacterial infections The differences in growth we measured

among treatment groups were not statistically significant and do not appear13 biologically13

meaningful during the relatively short duration of this study (97 days) although the

cumulative effects of slightly reduced growth could be biologically meaningful over longer

time frames

Reductions in growth13 as a result13 o repeated chemical treatments are not likely the

cause of differences in growth rates among facilities that raise razorback suckers

Repeated chemical treatments may have other impacts to overall fitness or long-shy‐term13

survival but these13 effects13 were13 not evident in our study It is more likely that the parasite

outbreaks themselves are the cause of different growth rates among razorback rearing

facilities rather than the chemical treatments used to treat the parasites We recommend

that hatchery managers continue to use the chemicals that are most effective at controlling

ldquoIchrdquo13 at their individual13 facilities

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower Colorado Rive Multi-shy‐species13

Conservation Plan under Work Task C10 We thank Ty Wolters and Tom13 Burke for their

support of this research and Frank Agygos and Dave Billingsly of the Bubbling Ponds Fish

Hatchery13 for their13 technical assistance13 and13 help with13 collecting13 fish

34

13

III13 Razorback Growth Rates at Bubbling Ponds ndash 2009-shy‐2011

Section13 SummaryExperimental studies at Bubbling Ponds Fish Hatchery AZ have strived to understand

factors that affect razorback sucker growth in captivity and identify ways to improve growthrates and maximize size at release Rather than performing experimental studies that wouldrequire major13 rearrangement (and likely reduced production)13 of hatchery operations our13 studies13 used normal variation in production techniques13 and practices13 to isolate factors13 thatmay modify growth rates

Our initial work identified razorback13 growth rates in13 lined ponds at standard fishdensity as 026 to13 028mmday (789 to 843 mmmonth) No significant differences in growthrate were observed among fish that had been in the pond only during the winter13 periodcompared to fish that had been in the pond the entire year indicating that water temperatures13 at Bubbling Ponds are high enough to allow fish to incorporate feed effectively year-shy‐roundHowever these growth rates are lower than most values reported from the literature fromnatural or semi-shy‐natural pond environments No significant differences in13 growth rate wereobserved13 between large and13 small fish13 within the 150 ndash 29 mm TL13 size range Additional worksuggests13 that razorback suckers13 tagged at over 300 mm TL had reduced growth rates (024mmday 73 mmmonth) as would be expected according to a typical Von13 Bertalanfy growthcurve although growth rates13 were only slightly less13 than the average growth rate for thehatchery (027513 mmday 82513 mmmonth)

Sorting13 to13 separate small fish from large fish after the first year of growth is practicedesigned13 to allow smaller fish to ldquocatch uprdquo to larger fish We found that13 this technique doesappear to13 improve growth rates of smaller fish Growth rates of sorted small razorback suckers(029 mmday 87mmmonth)13 were equal to that13 of larger13 fish (028 mmday 8413 mmmonth)indicating that sorting may have helped to offset their original slower growth trajectory

Bubbling Ponds Fish Hatchery grows razorbacks in 6 long deep ponds lined with heavyplastic 2 long deep13 earthen13 (unlined) ponds and three wide shallow earthen ponds The wideshallow ponds13 have historically produced very large fish at low density but have been found tomaintain much lower fish numbers than deeper ponds We found13 that growth13 rates ofrazorbacks kept at high density (4-shy‐700013 fish)13 in a wide shallow pond grew extremely slowly(024 mmday 726 mmmonth) This growth rate is among the slowest of any fish over theyears of our study and demonstrates that13 though the large ponds may produce large fish at lowdensity13 they are unable to overcome high13 fish13 densities

Finally one of the major factors influencing13 fish13 growth13 in hatcheries is disease onemajor summer-shy‐time disease at13 Bubbling Ponds is the ectoparasite Ich (Ichthiopthirusmultifiliis) To investigate the impact Ich has on razorback growth we eradicated fish from thespring and water conveyance ditch that supplies13 water to the hatchery using Rotenone This13 restoration effort was fairly short-shy‐lived (Ich returned to the hatchery within four months) but

35

13

growth13 rates of fish13 reared for four months without Ich present (031 mmday 92 mmmonth)were significantly higher than the following 8 months of growth for those same fish (022mmday 65 mmmonth) This disease-shy‐free growth rate is in fact faster than any13 otherprevious growth rates observed at the hatchery in our study

We conclude that growth rates at the Bubbling Ponds Fish Hatchery are likely as highas possible given the pond densities required to13 meet production goals and the Ich-shy‐infestedwater13 that feeds the facility Sorting practices are successful in helping as many fish as possiblereach stocking length as fast as possible Unlined ponds may be able to grow large fish at lowdensities but whatever factors allow for that growth13 are not able13 to overcome13 high fish densityThus the large lower ponds at Bubbling Ponds may be better utilized via renovation to13 deepenand line them

Disease is the most important factor limiting growth as may be expected to be the caseat many13 hatcheries While the spring renovation was not13 a complete success13 the dramaticreduction of fish populations in that habitat was enough to dramatically13 reduce13 the13 occurrenceof Ich at the hatchery13 Such open spring13 systems feeding a hatchery are a misfortune that canbe expected to transmit disease so we suggest that renovating the spring again to combat13 IchImproved techniques to divert water from13 the springs and more throuough treatment ofstream-shy‐side vegetation may improve the success of chemical treatment Successful renovationwould likely both improve growth rates and reduce chemical costs associated with treating Ichoutbreaks Even13 if complete renovation13 is impossible or impractical an13 effort to reduceinvasive fish density in the springs13 which act a vector for the parasite(and thereby reduce thelikelihood of13 Ich being transmitted into ponds) may still13 show dramatic improvements

36

13

Introduction

Conservation efforts13 for razorback sucker13 (Xyrauchen texanus)13 currently13 depend on

captive rearing and stocking programs Low survival of stocked razorback suckers (Brooks

1986 Marsh13 and13 Brooks13 1989 Marsh13 and13 Pacey13 2005) has13 caused13 target sizes for stocked13

fish to steadily increase in efforts to reduce predation mortality13 (Marsh13 et al13 2005

Schooley and Marsh 2007) Rearing fish to larger sizes at hatcheries comes with increased

costs and creates the need to evaluate husbandry and rearing practices that may affect fish

growth13 We evaluated growth13 rates13 of individual razorback suckers13 in ponds13 at Bubbling

Ponds Fish Hatchery13 using Passive Integrated13 Transponder (PIT) tags13 to13 obtain13 precise

growth information for individual fish so that valid comparisons of growth rates as related

to rearing practices can be made

Due to the critical nature of the razorback sucker stocking program we did not

design experimental studies that would require major rearrangement and potentially

reduce production of hatchery operations Instead our studies used normal variation in

production techniques and practices to isolate factors that may modify growth rates

Though this methodology dramatically limits replication and may limit our ability to

directly13 attribute13 differences in growth13 rates13 to13 the13 variables13 we13 investigate13 we13 were13 able13

to accomplish research goals without altering hatchery operations or impacting

production

From13 2009 through 2011 we conducted a series of observational13 growth13 studies to

determine growth rates of individual razorbacks at Bubbling Ponds The first set of

experiments included13 identifying13 growth13 rates13 in lined13 and13 unlined13 ponds determining

growth13 rates13 of fish at different13 sizes13 in13 relation13 to sorting13 practices and monitoring

razorback growth rates after removing the source of the ectoparasite13 Ich (Ichthiopthirus

multifiliis) from13 the hatchery water source13

Razorback growth rate in lined ponds

Our first growth study documented individual growth rates at normal density in 11

million gallon lined ponds13 over two13 years13 This is the standard13 grow-shy‐out process for

razorbacks13 at Bubbling Ponds We monitored growth of fish for a variety13 of sizes and13 the13

37

13

amount of time in a pond during the growing season These13 data give a snapshot of growth13

rates13 at the13 facility13 and13 provide13 the basis for comparisons throughout our study

Growth rate13 in an unlined pond

In addition13 to 6 ponds lined with heavy plastic13 sheeting13 Bubbling Ponds Fish13

Hatchery maintains two narrow and deep (same dimensions as lined ponds13 Figure13 4)13 and13

three large13 shallow unlined ponds These earthen13 ponds typically have vegetation and

associated aquatic invertebrates that may better simulate natural environments by

providing cover and improved food diversity or quality Therefore these unlined ponds

may be expected to produce higher growth rates and potentially improved survival that is

more similar to growth rates observed in more natural grow-shy‐out facilities13 Historically13 the13

large13 shallow13 ponds have produced very large fish when13 utilized at low13 fish density13 The

narrow13 deep earthen13 ponds are13 used to grow13 fry13 at high density in their first13 year of life

The major downside to unlined ponds is the difficulty in harvesting fish where a lined

pond might take 8-shy‐1013 people13 a half13 day13 to13 harvest13 lined13 ponds13 require13 intensive13 weeding13

to allow seines to be pulled and therefore require many more personnel-shy‐hours13 In addition13

to harvest challenges the shallow earthen ponds tend to suffer from13 dissolved oxygen

crashes during the summer Unlined ponds also may maintain higher13 populations13 of non-shy‐

target species such as bluegill sunfish mosquito fish and bullfrog tadpoles We measured

growth rates of suckers in a large shallow earthen pond for comparison to growth in lined

ponds13

Figure13 4 Lined13 and13 earthen ponds13 of similar dimensions (approx 1000000 gallons first

and second panels) and a large13 shallow13 earthen13 pond (third panel)

38

13

Effect of sorting on growth

Razorback13 suckers13 are13 currently13 sorted13 after their first13 year of growth13 They are13

typically removed from13 one of the13 upper earthen13 ponds and13 split into13 two13 lined13 ponds for

subsequent grow-shy‐out13 The larger13 fish (gt approximately 140 mm) are placed into one pond

and the smaller individuals in another It is possible that the larger fish were more

aggressive or adept13 at taking food so this sorting process is intended to allow smaller fish

to improve their growth rate

Effect of Ich on razorback sucker growth rates

We13 evaluated13 growth13 rates13 of razorback sucker13 in the13 presence13 and absence of the

ectoparasite13 Ich (Ichthiopthirus multifiliis) Ich outbreaks can occur in wild populations13 but

hatcheries13 have13 proven excellent locations13 for Ich because13 of very high fish densities13 which13

facilitate13 the13 transfer13 of Ich13 between13 fish This common fish parasite causes direct mortality13

to razorback13 suckers as well13 as secondary bacterial13 infections13

The open spring and13 ditch13 which13 provides water to the Bubbling13 Ponds Hatchery

has long13 been infested with mosquitofish (Gambusia affinis) that harbor13 the13 Ich parasite13

and allow13 it13 to enter the hatchery with incoming13 water13 The solution13 to13 the13 Ich problem13

was to remove the mosquitofish host using13 Rotenone Razorback13 sucker growth13 rates were13

then tracked in13 the absence of this parasite for 4 months and compared with growth rates

after Ich returned to the pond and from13 previous years

Methods

Razorback growth rate in lined ponds

On May 14 2008 141 razorback suckers were tagged with 12 mm PIT tags (1342

kHz) and placed in Pond 3 (approximately 1100000 gallons13 Figure13 4)13 at Bubbling13 Ponds

Fish Hatchery Fifty-shy‐three of these tags were recovered two months later when a large

Ichthyophthirius multifilis (Ich) outbreak killed many fish in the pond On October 15 2008

an additional13 145 PIT tagged13 fish were13 also placed into Pond13 3 On13 May13 14 2009 Pond13 3

was harvested and a total13 of 141 PIT tagged fish were recovered13 Of the tagged fish13 26 fish

had13 been13 in the13 pond since May13 of 2008 (378 days13 o growth) and 115 had been13 in13 the

39

13 40

pond since October13 15 2008 (211 days13 of growth) Numbers of fish in Pond 3 after the Ich

outbreak and for the majority of the period of growth were between 3 000 and 4000 fish

A Hobotempreg temperature13 logger13 was13 also13 installed13 in Pond 3 one meter below the water

surface13 near13 the13 outflow and13 recorded water temperature every 3 hours to allow analysis

of the effects of water temperature on growth rate (Figure13 5) This Hobotemp data is

representative of other pond temperatures throughout this study

In a second experiment 210 adult13 razorback suckers13 were13 PIT tagged13 on13 May 14

2009 and13 placed13 into13 Pond13 3 upper to13 evaluate13 growth13 rates13 of larger13 razorback suckers13 at

Bubbling13 Ponds Hatchery13 under current13 rearing13 conditions13 Size of these fish at tagging13

was (mean = 285 mm range = 205 ndash 396 mm) These fish remained in the pond for 257

days and were harvested on Jan 25 2010 to provide information on growth rates of larger

razorback suckers13 under13 current rearing conditions

Figure 513 Temperatures (degC) inrearing pond at BubblingPonds Hatchery from July toSept 2009 (top graph)13 andfrom Nov to Dec 2009 (Lowergraph) Temperaturesrecorded with a Hobotempregremote data logger13 every 3hours

13

Growth rate13 in an unlined pond

To document razorback sucker growth in earthen ponds we introduced13 225 tagged13

razorback suckers13 into13 Pond13 1 lower13 (Figure 4) in February 3 2010 Additional tagged fish

from13 other studies were added to the pond throughout the growing season and the density

of 1 lower reached a maximum13 of nearly 7000 fish in early summer 2010 Density was

reduced to approximately 6000 fish by capturing fish with hoop nets on June 3 2010 54 of

these fish were tagged fish and returned to 1 lower after being weighed and measured The

pond was harvested on January13 2713 2011 and a total13 of 254 tagged fish out13 of 4296 fish

total were removed from13 the pond The pond was harvested on January 27 2011 (358 days13

of growth) and the tagged fish were weighed and measured Total number of razorbacks in

the pond at harvest13 was 4296

Effect of sorting practices on growth rates

On March 1113 200913 Pond13 5 upper was13 harvested13 and13 split into13 two13 separate13 groups

Two hundred of the smaller fish (average size = 122 mm TL) were PIT tagged and placed

into13 Pond13 7 upper and13 200 of the13 larger13 fish (average = 160 mm TL) were PIT tagged and

placed int Pond13 8 upper Density13 in Pond13 7 was13 4500 fish and13 in Pond13 8 there13 were13 6500

fish These ponds were then harvested after 1 year and growth rates were compared to

give information on the effects of current sorting practices Hobotempreg temperature

loggers were installed in13 Ponds 7 and13 8 during13 the13 grow-shy‐out period with13 water13

temperature recorded every 2 hours13 (Figure13 6)

Effect of Ich on razorback sucker growth rates

Bubbling Ponds spring was treated with Rotenone (CFT Legumine 5) at a

concentration of 2 ppm13 to remove all mosquitofish from13 the spring The treatment

consisted of two treatments 6 hours in duration on two consecutive days (April 12 -shy‐ 13)

using13 drip13 stations13 and13 backpack sprayers13 followed13 by13 an13 additional 6 hours13 of

detoxification using sodium13 permanganate Although 12 mosquitofish were captured in the

spring pond the week following the treatments subsequent minnow trapping (20 traps

checked13 daily13 for 3 weeks) did not capture any additional fish until August 11 2010 when

41

13

juvenile mosquitofish were again detected in the spring pond Minnow traps have

subsequently been set daily with several hundred individuals removed To evaluate if Ich

was also again present in the spring we captured 15 mosquitofish from13 the spring pond on

three separate days and placed them13 in an aquaria at 25 degC with 5 longfin dace known to be

free of Ich These fish were monitored for 2 weeks with no signs of Ich developing This

indicates that even though mosquitofish have returned to the spring pond the parasite is no

longer present13 although how13 long13 this condition13 will13 persist13 is unknown13

On May 1113 201013 200 juvenile razorback13 suckers were harvested out13 of Pond 5

upper (2009 year Class from13 Dexter National Fish Hatchery) and were PIT tagged and

placed into Pond 8 to evaluate if growth rates at bubbling ponds hatchery have improved

following the renovation of the spring and the removal of the Ich parasite Unfortunately13

on Sept13 8 2010 Ich was13 again13 detected13 in Pond 8 and the pond was immediately seined

and 74 tagged fish were measured to obtain growth information for the 4-shy‐month period

during13 which13 the13 pond13 was13 Ich-shy‐free13

Figure13 6 Temperatures (degC) in rearingponds 7 and 8 at Bubbling Ponds Hatchery13 from March 2009 ndash March 201013 pond 7(top13 graph)13 and13 pond 8 (Lower13 graph)13 Temperatures recorded with a Hobotempregremote data logger every 3 hours

42

13

Results

Growth in Lined Ponds

Razorback suckers13 that had been13 in13 Pond 8 upper for the13 entire13 year13 grew an13

average of 0263 mmday (789 mmmonth) and razorback suckers that had been in the

pond for 7 months (Oct -shy‐ May) grew13 on13 average of 028 mmday (843 mmmonth) (Figure13

7) These growth13 rates13 did not significantly13 differ Fish density13 in Pond 3 during13 the13

majority of the growth period was13 00032 ndash 00036 fishgallon13 Additionally no13 significant

differences in growth rate were observed between fish smaller than 210 mm TL and fish

larger than 210 mm TL when all recaptured fish were combined

We also measured the growth rate of very large fish in a lined pond On Jan13 2513 201013

156 adult fish with PIT tags were recovered from13 Pond 3 upper13 These fish were13 in the13

pond for 257 days and experienced an average13 growth13 rate13 of 024mmday or 73

mmmonth (Figure13 7)13 This growth13 rate13 is slightly13 lower13 than13 the13 average13 growth13 rate13

observed13 at Bubbling13 Ponds Hatchery in other studies (0275 mmday 825 mmmonth)

but may not be biologically meaningful We would expect larger13 fish to13 have13 reduced

growth rates according to a typical Von Bertalanfy growth model (Bertalanffy 1957) but it

appears that13 over the size range we evaluated (300 -shy‐ 450 mm TL) growth rates have not

slowed significantly compared to that of smaller13 fish grown at Bubbling Ponds13 Hatchery

Growth13 of razorback suckers13 is known13 to13 slow as13 fish reach13 larger13 sizes but it appears13 this13

reduced growth rate may not really start to be biologically meaningful at Bubbling Ponds

Hatchery13 until razorback suckers13 exceed 450 mm TL

Growth in unlined ponds

Growth13 rates13 for the13 fish recaptured13 during13 the Pond 1 lower13 thinning13 (120 days13 in

the pond) was 024 plusmn 003 mmday (729 plusmn 090 mmmonth) (Figure13 8)13 Fish13 that were13 in

the pond for nearly the entire year grew13 an13 average13 of 024 plusmn 001 mmday (726 plusmn 027

mmmonth) These growth rates are surprisingly the lowest measured growth rates for

any part of our study and differ significantly from13 every other measured growth rate

except very large13 fish (Figure13 9)13 Separating13 out13 large fish that13 were in13 the pond for the

entire year makes no difference fish that were added to the pond at TL lt300 mm grew

43

13

Gro

wth

Rat

e (m

md

ay)

020

026

032

0244 plusmn 001 mmday (733 plusmn 028 mmmonth) and and those with TL gt= 300 mm at the

start of the experiment grew 022 plusmn 003 mmday (651 plusmn 101 mmmonth)

Razorback Growth Rates in Lined Ponds

Figure 7 Growth ofrazorback suckers in(mmday plusmn standard error)in Pond 8 upper in 2008-shy‐2009 An ANOVA did notdetect any significantdifferences

7 Months Full Year 300+ mm fish

Effects of sorting on growth

One hundred and seventy five tagged razorback suckers were recovered from13 Pond

8 upper13 on March13 24 2010 (378 days13 of growth)13 These were13 the13 larger sorted13 fish (gt140

mm TL) that came out of Pond13 5 on March13 11 2009 One13 hundred and13 twenty13 two13 tagged13

razorback suckers were also recovered from13 Pond13 7 upper on March13 31 2010 (385 days13 of

growth)13 These were13 the13 smaller sorted13 fish (lt140 mm TL) that came out of Pond13 5 on

March 1113 200913 No significant differences in growth rate (mmday) were observed among

larger fish in Pond 8 and smaller fish in Pond 7 (pgt005 ANOVA) (Figure 10)13 indicating

that13 sorting may have helped to offset the original slower growth trajectory of the smaller

fish Temperatures of Ponds 7 and 8 upper remained similar throughout the year13 (Figure

5)

44

13

13

13

Gro

wth

Rat

e (m

md

ay)

Gro

wth

Rat

e (m

md

ay)

020

026

032

020

026

032

Razorback Growth in an Unlined Pond

Figure 8 Growth of razorbacksuckers (mmday plusmn standard error) in Pond 1 lower (an unlined pond)in 2010-shy‐2011 An ANOVA did notdetect any significant differences

6 Months 12 Months lt 300 mm Fish 300+ mm Fish Growth Growth

Lined vs Earthen Ponds 1 year of growth

Figure 9 Growth of razorbacksuckers (mmday plusmn standard error) in lined and unlined ponds A t-shy‐test13 did not detect a significantdifference

Lined Pond Unlined Pond 1 Yr Growth 1 Yr Growth

45

13

Effect of Sorting G

row

th R

ate

(mm

day

) G

row

th R

ate

(mm

day

)

032

020

026

032

020

026

Smaller Fish Larger Fish

Effect of Ich

Figure 10 Average growthof razorback suckers(mmday plusmn standard error)that were size-shy‐sorted intosmall fish (pond 7) and largefish (pond 8) populations At-shy‐test did not detect asignificant difference

Figure 11 Average growth ofrazorback suckers (mmday plusmnstandard error) after Ich wasremovd from the hatcheryrsquos springand after Ich was again detected inthe pond The growth rate withoutIch is significantly higher than boththe rate after Ich and the ourstudyrsquos average annual growth ratein lined ponds (ANOVA p =00003)

Growth without Ich Growth With Ich Average Annual 4 months 4 months Growth Rate

46

13

Effect of Ich on razorback sucker growth rates

Seventy-shy‐four13 tagged13 razorback suckers13 were13 recovered from13 Pond 8 on September

15 2010 These fish had13 been13 in the pond for 4 months and experienced a growth rate of

032 mmday or 97 mmmonth (Figure13 11)13 This growth13 rate13 is significantly higher (p =

005 two sample t-shy‐test) than the mean growth rate for the same group13 of tagged fish after

Ich detection (022 mmday or 65 mmmonth) and significantly higher than any other

individual growth13 rates13 observed13 to13 date13 at Bubbling13 Ponds Hatchery13 (Figure13 11)13 If this13

growth13 rate13 were13 extended throughout13 the entire13 year13 fish on average from13 Ich-shy‐free13 ponds13

would be 16 mm longer than fish from13 ponds infested with Ich Studies conducted at

Bubbling Ponds hatchery in 2008 (Ward 2008) did not reveal any effects of the treatment

chemicals on razorback sucker growth rates so it13 is likely that13 the parasite outbreaks

themselves are causing reducing growth rates rather than the chemicals used to treat the

parasites13

Conclusions

Our results suggest that under typical hatchery operations (maximizing number of

fish produced)13 the growth13 rate13 of razorback13 suckers13 is relatively13 consistent at Bubbling13

Ponds hatchery13 at 02-shy‐03 mmday (6-shy‐9 mmmonth)13 but is lower than growth13 rates13 at

other13 facilities (02 ndash 18 mmday Ward et al 2007)13 This growth13 rate13 has13 been13 constant in

both lined and unlined ponds and at all fish densities we were able to measure To achieve13

growth13 rates13 substantially higher than this will likely require13 significant changes in rearing

practices that may not be practical in order to reach numerical production13 goals

Temperature is a key variable in fish growth but seasonal growth patterns

described13 above13 (Figure13 5) demonstrate that water temperatures are high enough in

winter to maintain razorback growth Differences in water temperature by season

currently13 do not fluctuate more than 10degC at Bubbling Ponds because of the continuous

supply of water flowing through each pond (approx 225 gallonsmin) These high water

flows appear to keep pond temperatures within the thermal preference13 for razorback

suckers13 (1213 -shy‐ 28 degC Bulkley and Pimentel 1983) throughout the entire year with

temperatures rarely dropping13 below 16deg13 C (Figures 513 6)13

47

13

Fish density is another key variable in fish growth and though the number of fish in

a pond during our study ranged from13 3000 to 700013 fish we13 did not find any13 correlation13

between13 density and growth rate13 This might yield two conclusions First13 razorback

growth13 may be changed equally13 by13 densities13 at the13 hatchery13 (ie13 a density13 of 3000 fish in a

pond is as stressful13 for razorbacks as a density13 of 7000 fish) An alternative is that other

factors13 such as disease outbreaks have13 stronger13 control over fish growth13 than13 density13

Fish density13 would13 have13 to13 be13 experimentally manipulated to test13 this13 and hatchery

operations (producing the maximum13 number of fish) prevented our manipulating density13

in ponds for this13 work The trouble with manipulating density demonstrates the difficulties

associated with changing13 hatchery13 practices experimenting with density would have

prevented BPH from13 meeting13 production13 goals Given that the stocking of smaller

razorbacks has met with very little success perhaps BPH goals could be changed from13

producing 12000 fish at 300+ mm per year to a smaller number of very large fish each

year Growing13 fewer13 larger13 fish could potentially be accomplished in the same time frame

as more smaller fish but a better understanding of how density alters growth rate would

be required to be confident13 of this

The very slow growth13 in the13 earthen13 unlined13 Pond 1 lower13 was very surprising We13

had13 anticipated13 that the13 diversified diet13 cover and13 other13 habitat features13 provided by13

unlined ponds would yield dramatically increased growth rates However these traits were

not enough to offset high fish densities and in fact the unlined pond in our study13 suffered

mortality to bring densities down to that observed normally in lined ponds

Our data13 suggest13 that razorbacks13 sucker13 growth13 rates13 are13 higher in lined13 ponds13

However we13 think the reasons13 for the13 very slow growth we observed13 in the13 unlined13 pond13

in our study13 is instead13 linked13 to13 the13 usage13 of Pond 1 lower13 during13 the13 study13 rather13 than13

intrinsic13 slow growth13 in earthen13 ponds First the pond was at extremely high density for at

least part of the study The volume of Pond 1 lower has not been estimated but hatchery

managers suggest 1500-shy‐2000 fish is an appropriate number of individuals so this pond

was at a very high density for much of the experiment Second dissolved oxygen is often

very low in the13 large13 earthen13 ponds during the heat of summer much lower than that of

lined ponds This will both limit the number of fish that can survive in the pond and almost

certainly13 increases stress13 of these13 fish potentially13 reducing growth13 The DO crashes also13

48

13

limit the amount of feed hatchery managers can give fish in these ponds sometimes for

days or weeks at a time which further reduces growth during warm13 weather

Our data13 suggests that13 growth rates at the Bubbling13 Ponds Fish Hatchery are likely

as high as possible given13 the pond densities required to meet production goals and the Ich-shy‐

infested water that feeds the facility Sorting practices are successful in helping as many

fish as possible reach stocking length as fast as possible Unlined ponds may be able to

grow13 large13 fish at low13 densities13 but whatever factors allow13 for that13 growth are not13 able to

overcome high fish density The removal of invasive13 fis that act as13 a host for the13 parasite13

Ich fish from13 the Bubbling13 Ponds spring13 allowed the highest13 growth rate at 032 mmday13

(96 mmmonth) but that growth rate decreased again as Ich re-shy‐infested13 the13 hatchery13

Consistently13 achieving13 growth13 rates13 as high or substantially13 higher than13 this13 will likely13

require13 significant changes in rearing practices that may not be practical in order to13 reach13

numerical production13 goals

Two major changes that might result in higher growth rates are substantially

reducing fish density and modifying the way spring water is delivered to the facility (via

either repeated chemical treatments or enclosed concrete water diversions) to eliminate

Ich from13 the hatchery source water Other potential changes not address by our work

include13 flow-shy‐training razorbacks much previous literature including MSCP-shy‐funded13 work

on razorback suckers13 suggests13 that fish growing13 in flowing water will grow13 faster than fish

in still water (Jorgensen and Jobling 1994) Furthermore there are a wide variety of

potential benefits associated with growing13 fish13 in flowing13 water in addition13 to increased

growth13 rates13 (Davidson13 199713 Castro13 et al13 2011) Another option13 for increasing13 growth13

rates13 include13 changing to13 intensive13 culture13 in large circular13 tanks

Finally given that the stocking of smaller razorbacks has met with very little

success13 perhaps13 BPH13 goals13 could13 be13 changed from13 producing 12000 fish at 300+ mm per

year to a smaller number of very large fish each year Growing fewer larger fish could

potentially be accomplished in the same time frame as more smaller fish but a better

understanding13 of how density13 alters growth13 rate13 would13 be13 required to13 be13 confident of this

49

13

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower13 Colorado13 River Multi-shy‐Species13

Conservation Program13 (LCRMSCP) under Work Task C10 We13 thank Ty Wolters13 Tom13

Burke13 and Eric13 Volkman for their support of this research and Frank Agygos and Dave

Billingsly13 of the Bubbling13 Ponds Fish Hatchery13 for their willingness to participate in13 this

research13 and13 for their technical assistance We also thank the LCRMSCP fish group from13

Boulder City13 NV for their assistance with harvesting13 ponds and tagging13 fish13

50

13

Literature13 CitedAnders P J 1998 Conservation aquaculture and endangered species can objective science13

prevail13 over risk13 anxiety Fisheries 23(11) 28-shy‐31

Anderson R O and R M Nuemann 1996 Length weight and associated structural indicesPages 447 ndash 482 in B R Murphy13 and D13 W Willis13 editors13 Fisheries techniques13 2ndedtion American Fisheries13 Society13 Bethesda13 Maryland

Bain M B J T Finn and H E Brooks 1988 Streamflow regulation and fish communitystructure13 Ecology13 69382-shy‐392

Bays J H Zarbock R Whitman and T Murphy 2005 Conceptual design and managementof native13 fish refugia on the13 lower13 Colorado13 River In13 CL Spring13 and13 S Leoneditors Proceedings of two symposia Restoring native fish to the lower ColoradoRiver13 interactions13 of native and non-shy‐native13 fishes 13ndash1413 July13 1999 Las13 Vegas13 Nevada13 Restoring13 natural function within a modified riverine environment thelower Colorado River13 8ndash913 July13 1998 U S Fish and13 Wildlife13 Service Southwestern13 Region Albuquerque New Mexico Pages 167-shy‐177

Bertalanffy L Von 1957 Quantitative laws in metabolism13 and growth13 Q Rev Biology 32217 ndash 231

Bingham T B Scheer and C McAda 2003 Propagation facilities in Grand Valley (24 RoadHatchery Horsethief13 Ponds and13 grow-shy‐out ponds) for captive13 rearing13 ofendangered13 fishes for the13 upper13 Colorado13 River basin13 Colorado River RecoveryProgram FY2003 annual project report13 US Fish and13 Wildlife13 Service GrandJunction13 4pp

Birchell G J and K Christopherson 2004 Survival growth and recruitment of larval andjuvenile razorback13 sucker (Xyrauchen texanus) introduced13 into13 floodplain13 depressions13 of the13 Green River Utah13 Final report13 Upper13 Colorado13 RiverEndangered Fish Recovery Program13 Project No C-shy‐6RZ Publication Number 04-shy‐1513 Utah13 Division of Wildlife13 Resources Salt Lake13 City13 Utah13 67 pages

Brannon E L 1993 The perpetual oversight of hatchery programs Fishery Research 1819-shy‐27

Brett J R 1979 Environmental Factors and growth pages 599-shy‐67513 InW S Hoar13 D13 J13 Randall and J R Brett (eds) Fish Physiology Volume 8 Bioenergetics and GrowthAcademic Press New York

Brooks J E 1986 Annual reintroduction and monitoring report for razorback suckerXyrauchen texanus in the Gila River Basin Arizona 1985 US Fish and WildlifeService13 Offices of Endangered13 Species and Fishery13 Resources Albuquerque 23 pp

51

13

Brunson13 R E and K D13 Christopherson13 200513 Larval13 razorback13 sucker and bonytailsurvival and13 growth13 in the13 presence13 of nonnative13 fish in the13 Baeser13 floodplainwetland of the middle Green River Final report prepared for Upper13 Colorado RiverBasin Endangered Fish Recovery Program Project No C-shy‐6-shy‐rz-shy‐bt Publication13 No 05-shy‐26 Utah13 Division of Wildlife13 Resources13 Vernal13 32 pp

Bulkley R V and R Pimentel 1983 Temperature preference and avoidance by adultrazorback suckers Transactions of the American Fisheries Society 112601-shy‐607

Burke13 T13 199513 Rearing13 wild razorback13 sucker larvae in13 lake-shy‐side13 backwaters13 LakeMohave ArizonaNevada Proceedings of the Desert Fishes Council 2635

Busacker G P I R Adelman and E M Goolish13 199013 Growth13 Pages 363 ndash 387 in C BSchreck and p B Moyle editors Methods for fish biology American FisheriesSociety Bethesda Maryland

Castro V B Grisdale-shy‐Helland S J Helland T Kristensen S M Jorgensen J Helgrud13 GClaireaux A P Farrell A Krasnov and H Takle 2011 Aerobic training stimulatesgrowth and promotes disease resistance in Atlantic salmon (Salmo salar)Comparative Biochemistry and Physiology -shy‐ Part A Molecular amp IntegrativePhysiology13 160(2) 278-shy‐290

Czapla T E 2002 Facilities plan for the production of endangered fishes to meet statestocking13 plans13 as13 part of the13 Upper13 Colorado13 River Endangered13 Fish RecoveryProgram Upper Colorado River Basin Recovery Implementation Program US Fishand Wildlife Service13 Denver13 9 pp

Davidson W 1997 The effects13 of exercise13 training on teleost fish a review of recentliterature Comput Biochem Physiol 117A67ndash75

Figiel Jr C R 2005 Annual report fiscal year 2004 Willow Beach National13 Fish HatcheryUS Fish and Wildlife13 Service Willow Beach 17 pp

Figiel Jr C R M E Ulibarri G Carmichael J Seals and J N Hanson 2005 Intensive13 fish13 culture of warmwater native fishes at a coldwater fish hatchery Pages 164-shy‐16613 inProceedings of two symposia restoring native fish to the lower Colorado13 River13 interaction13 of native13 and13 non-shy‐native13 fishes July13 13-shy‐1413 1999 Las Vegas Nevada USFish and Wildlife Service Southwest Region Albuquerque New Mexico

Gerking13 S D 1978 Ecology of freshwater fish13 production13 Halstead Press13 New13 York

Gustafson W and Q Bradwisch 2000 Wahweap operation and maintenance -shy‐-shy‐ UtahColorado River Recovery Program FY 2000 annual project report Project No 29cUtah13 Division of Wildlife13 Resources Page AZ 3pp

52

13

Hamman R L 1985 Induced spawning of hatchery-shy‐reared13 razorback sucker ProgressivFish Culturist 47(3) 187-shy‐189

Hanson J N 1996 Annual report fiscal year 1996 Willow Beach National Fish HatcheryUS Fish and Wildlife Service13 Willow Beach 9pp

Irving D S Seversen and M Montagne 2004 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2004 annual project13 report Report No 29b US Fish and13 Wildlife13 Service Vernal 3pp

Jorgensen E H and13 M Jobling 1994 Feeding and13 growth13 of exercised13 and13 unexercised13 juvenile Atlantic salmon in freshwater and performance after transfer to seawaterAquaculture International 2 154-shy‐164

Kaeding L R and D B Osmundson 198913 Colorado13 Squawfish13 and13 razorback sucker grow-shy‐out pond studies as part of conservation measures for the green mountain andRuedi reservoir water sales Final report for agreement number 6-shy‐AA-shy‐60-shy‐00150

Koebele13 B P13 198513 Growth and the size hierarchy effect an experimental assessment ofthree proposed mechanisms activity differences disproportional food acquisition13 pysiological stress Environmental Biology of Fishes 12 181-shy‐188

Kretschmann A E and L L Leslie 2006 Razorback sucker (Xyrauchen texanus) status13 reproduction and recruitment in Senator Wash Reservoir CA Final Report13 to USBurea of Reclamation Cooperative Agreement No 00-shy‐FG-shy‐34-shy‐ 0009 p 32 ArizonaGame and Fish Department Phoenix

Marsh13 P13 C13 1987a13 Digestive tract13 contents13 of adult razorback suckers13 in Lake13 MohaveArizona-shy‐Nevada Transactions of the American Fisheries Society 116117-shy‐119

Marsh P C 1987b Native fishes at Buenos Aires National Wildlife Refuge and ArizonaState University Research Park Arizona opportunities for management researchand public13 education13 on13 endangered species13 Proceedings of the Desert13 FishesCouncil 1967-shy‐78

Marsh P C 1994 Rearing native Colorado River fishes in golf course ponds Arizona StateUniversity Tempe 22 + pages

Marsh13 P13 C13 200013 Fish population13 status and evaluation13 in13 the Cibola13 High Levee PondFinal report agreement number 99-shy‐FG-shy‐30-shy‐00051 US Bureau of ReclamationBoulder City13 Nevada13 20 pages

Marsh P C and C A Pacey 1998 Growth of wild adult razorback suckers13 in Lake13 Mohave13 Arizona-shy‐Nevada13 Final report13 US Bureau of Reclamation Boulder City Nevada 25pages + appendices

53

13

Marsh P C B R Kesner and C A Pacey 2005 Repatriation as s management strategy13 to13 conserve a critically13 imperiled fish species North American Journal of FisheriesManagement 25 547-shy‐556

Marsh P C and C A Pacey 2005 Immiscibility of native and non-shy‐native13 fishes Pages 59-shy‐63 inMJ13 Brouder13 CL13 Springer13 and CS13 Leon13 editors13 Proceedings of two13 symposia Restoring native fish to the lower Colorado River interactions of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 NV and13 Restoring natural13 function within a modified riverine environment the lower Colorado River13 July13 8-shy‐913 1998 Las Vegas NV US Fish and13 Wildlife13 Service Southwest Region AlbuquerqueNew Mexico

Marsh13 P13 C13 and J13 E Brooks13 198913 Predation13 by ictalurid catfishes as a deterrent13 toreestablishment of hatchery-shy‐reared13 razorback sucker The Southwestern Naturalist34188-shy‐195

Matthews R A 2005 Ichthyopthirus multifiliis Fouquet and Ichthyopthirosis infreshwater13 teleosts13 Pages13 159-shy‐218 in Advances in Parasitology volume 59 J RBaker R Muller D Rollinson (eds) Academic Press

McCarthy13 M S and W L Minckley 1987 Age estimation for razorback sucker (PiscesCatostomidae) from13 Lake Mohave Arizona and Nevada Journal of the Arizona-shy‐Nevada Academy of Science 2187-shy‐97

Minckley13 W L13 198313 Status of the razorback13 sucker13 Xyrauchen texanus (Abbot)13 in13 thelower Colorado River basin13 The Southwestern13 Naturalist13 28(2) 165-shy‐187

Minckley13 W L13 199113 Native fished of the Grand Canyon13 region an obituary13 Pages 124-shy‐177 in Colorado River ecology and dam13 management National Academy PressWashington13 DC

Minckley13 C13 O and M LaBarbara13 199913 Report13 on13 native fish grow-shy‐out facilities13 at Cibolaand Imperial National Wildlife Refuges 1993-shy‐199513 US Fish and13 Wildlife Service13 Parker Fishery Resources Office Parker Arizona

Modde13 T13 199613 Juvenile razorback sucker (Xyrauchen texanus) in a managed wetlandadjacent13 to the Green13 River13 Great13 Basin13 Naturalist13 56375-shy‐376

Modde T KP Burnham and E J Wick 1996 Population status of the razorback sucker13 inthe middle Green River (USA) Conservation13 biology 10 110-shy‐119

Modde13 T13 and G13 B Haines13 200513 Survival13 and growth of stocked razorback13 sucker andbonytail in multiple floodplain wetlands of the middle Green River under resetconditions13 Final report prepared for Upper Colorado13 River13 Basin RecoveryImplimentation Program US Fish and Wildlife Service Vernal 66 pp

54

13

Modde T Z H Bowen and D C Kitcheyan 2005 Spatial and temporal use of a spawning13 site in the middle Green River by wild hatchery-shy‐reared13 razorback suckers13 Transactions of the American Fisheries Society 134937-shy‐944

Mueller13 G13 199213 The native fish work13 group13 -shy‐ a multiagency endeavor to improve thestatus of the razorback sucker in Lake Mohave AZ-shy‐NV13 Proceedings of the DesertFishes Council 2369

Mueller G 1995 A program13 for maintaining the razorback sucker in Lake MohaveAmerican Fisheries Society Symposium 15127-shy‐135

Mueller13 G13 200613 Ecology of the bonytail13 and razorback13 sucker and the role of offchannelhabitats13 in their13 recovery Scientific13 investigations13 report 2006-shy‐5065 US GeologicalSurvey13 Denver

Mueller G and E Wick 1998 Testing of golf course ponds at Page Arizona for suitability13 as grow-shy‐out facility for razorback sucker using surplus fish from13 Ouray NationalFish Hatchery National Park Service US Fish and13 Wildlife13 Service and UtahDivision of Wildlife13 Resources 28 pages

Mueller13 G13 and T13 Burke13 200513 Survival13 of young13 razorback13 sucker (Xyrauchen texanus) inrelation to13 stocking rates13 (fishha)13 and13 in the presence13 or absence13 of predatorcommunities in Lake Mohave Arizona-shy‐Nevada13 Pages13 155-shy‐16313 in Proceedings of two13 symposia restoring native fish to the lower Colorado River interaction13 of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 Nevada US Fish and Wildlife13 Service Southwest Region Albuquerque New Mexico

Mueller13 G13 J13 Carpenter13 and P13 C13 Marsh13 200413 Cibola13 High Levee Pond annual report 2004US Geological Survey Fort Collins13 Science Center13 Colorado13 and Arizona StateUniversity Tempe 23 pages

Nesler T P K Christopherson J M Hudson C W McAda F Pfeifer and T E Czapla 2003An integrated stocking plan for razorback sucker bonytail and Colorado13 pikeminnow for the Upper Colorado River Endangered Fish Recovery ProgramAddendum13 to State Stocking Plans Upper Colorado River Basin Recovery13 Implementation Program 12 pp

Papoulias13 D and W13 L Minckley13 1992 Effects13 of foo availability13 on survival and growth13 of larval razorback suckers13 in ponds Transactions of the American Fisheries Society121340-shy‐355

Paukert13 C P D L Ward13 P J Sponholtz13 and K13 D Hilwig13 Effects13 of repeated hoopnetting13 on bonytail chub13 Journal of Freshwater13 Ecology13 20(4) 649-shy‐653

Pfeifer F M13 C Baker13 and M13 Montagne13 199913 Propagation13 facilities13 in the13 Grand Valley13 (24 Road13 Hatchery13 Horsethief13 Ponds and13 grow-shy‐out ponds) for captive rearing of

55

13

endangered13 fishes for the13 Upper Colorado13 River Basin13 Colorado13 River Recovery13 Program FY 99 annual project report Project No 29a13 US Fish and Wildlife Service13 Grand13 Junction13 5pp

Pfeifer F S Seversen and M Montagne 2003 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2003 annual reportProject No 29b13 US Fish and Wildlife13 Service Vernal13 4pp

Rabago-shy‐Castro J L Sanchez13 J G Perez-shy‐Castaneda R and13 Gonzalez-shy‐Gonzlez A 2006Effects of the prophylactic use of Romet-shy‐3013 and13 copper13 sulfate13 on growth13 condition13 and feeding13 indicies in13 channel13 catfish (Ictalurus punctatus) Aquaculture 253 343-shy‐349

Reinitz GL L E Orme and F N Hitzel 1979 Variations of body compositio and growth13 among strains of rainbow trout Transactions of the American Fisheries Society 108204-shy‐207

Ruppert13 J13 B P B Holden13 and P D Abate 1999 Age estimation and growth of razorbacksucker13 Xyrauchen texanus in Lake13 Mead Nevada Proceedings13 of the Desert FishesCouncil 3040

Schnoor K D and J Logan 2002 Operation and maintenance of JW Mumma nativeaquatic13 species restoration facility Colorado Colorado River Recovery Program FY2002 annual project report13 Project No 29d Colorado13 Division of Wildlife Alamosa3pp

Salisbury13 L13 1998 Factors13 affecting razorback13 sucker growth13 in Lake13 Mohave backwaters13 MS Thesis13 Unviersity13 of Nevada13 Las13 Vegas

Schooley J13 D13 and P C13 Marsh13 2007 Stocking of endangerdd13 razorback13 suckers13 in thelower Colorado River Basin13 over three decades 1974-shy‐2004 North American Journalof Fisheries Management 27 43-shy‐51

Severson S H H M Tyus and G B Haines 1992 An evaluation of feeds for raisingrazorback sucker Xyrauchen texanus Journal of Applied Aquaculture 155-shy‐65

Toney D P 1974 Observations13 on the13 propagation13 and13 rearing13 of two13 endangered species13 in a hatchery environment Proceedings of the Annual Conference of the Western13 Association of State Game and Fish Commissions 54 252-shy‐259

Tyus H M13 1998 Razorback sucker13 (Xyrauchen texanus) recovery plan13 University13 ofColorado Center for Limnology Boulder13 76 pages

Tyus H M13 and13 S H Severson 1990 Growth13 and13 survival of larval razorback suckers fedfive formulated diets The Progressive Fish Culturist 52197-shy‐200

56

13

Ulibarri M E 2003 Annual report fiscal year 2001 Dexter National Fish Hatchery13 andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 26 pages

Ulibarri M E 2003 Annual report fiscal year 2002 Dexter National Fish Hatchery andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 59 pages

USBR 2006 Lower13 Colorado13 River Multi-shy‐Species Conservation Program final fishaugmentation plan Boulder City 19 pp

USFWS 2002 Razorback sucker (Xyraouchen texanus) recovery goals Amendment andsupplement to the Razorback Sucker Recovery Plan13 US Fish and Wildlife Service13 Region 6 Denver13 Colorado

USFWS 1999 Annual report 1999 Ouray National Fish Hatchery Vernal 25pp

USFWS 2004 Management plan for the big-shy‐river13 fishes of the13 lower13 Colorado13 river basinamendment and supplement to the bonytail humpback chub Coloradopikeminnow and razorback sucker recovery plans

USFWS13 2005 Station13 profile13 of the13 Dexter13 National Fish Hatchery13 and Technology CenterUS Fish and Wildlife13 Service Dexter

Valdez R A P G Mangan R Smith and B Nilson 1982 Upper Colorado River fisheriesinvestigations13 inW H Miller J J Valentine D L Archer H M Tyus R A Valdezand L13 Kaeding13 editors13 Colorado River Fishery13 Project13 Part 2 Field13 investigations13 US Bureau of Reclamation Salt Lake City Utah

WBNFH 2004 Culture methods of the endangered razorback sucker Xyrauchen texanusUS Fish and Wildlife13 Service Willow Beach National Fish Hatchery13 8 pp

Ward D 2008 Effects of disease treatments on growth of razorback sucker ReportSubmitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 Inpartial fulfillment of work task C10 agreement number 06FG30039

Ward13 D13 M Childs and W Persons 2007 Factors13 affecting13 growth13 of razorback sucker13 (Xyrauchen texanus) in captivity Literature review and knowledge assessmentReport Submitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 In partial fulfillment of work task C10 agreement number 06FG30039

57

Appendices

Appendix 1 Survey Questions Survey of Razorback Sucker Culture in the

Southwestern United States

The enclosed survey is being distributed by the Arizona Game and Fish Department to razorback sucker culture facilities throughout

the Southwestern United States The purpose of this survey is to consolidate information regarding culture of this species so that

appropriate facility improvements can be considered for Bubbling Ponds Hatchery in Arizona Specifically we wish to increase

growth rate and production efficiency at the hatchery Information gathered in this survey will be summarized in a final report to US

Bureau of Reclamation in Boulder City NV and disseminated to all facilities that participate in the survey A workshop to discuss

the findings of this study as well as to share general information concerning razorback sucker culture will be organized by the

Arizona Game and Fish Department at the conclusion of this study and all participants will be invited

Thank you for taking the time to fill out this survey Please contact Mike Childs if you have questions or would like to discuss the

survey

Mike Childs

mchildssedonanet

(928) 639-1346

(928) 634-1279

Facility_____________________________________ Date___________________

Contact Phone _____________________________

ContactPerson_______________________________

Contact Email _______________________________

1 Water quality ranges at this culture facility

Season

Spring (Mar-May) Summer (Jun-Aug) Fall (Sept-Nov) Winter (Dec-Feb)

Temperature (C)

PH

DO (mgL)

PO4 (mgL)

TDS (mgL)

Hardness (mgL)

CaCO3

Pathogens

37

13

Information from13 all of these sources is summarized to aid future researchers in the

design of more detailed studies on razorback sucker13 growth Understanding the13 factors13

that13 control13 razorback13 sucker growth will13 allow13 expanded fish-shy‐rearing capabilities13 and13 aid13

in reaching management objectives for stocked fish Preservation of genetic resources for

razorback suckers13 depends on captive rearing and stocking programs until permanent

solutions to factors that prevent wild recruitment can be found

Summary13 of Facilities

There are13 over 50 locations13 that have13 been13 used to13 rear13 razorback suckers13 (Table13 1) These

include13 both13 intensive13 culture13 facilities13 with13 raceways13 or circular13 tanks13 as13 well as13

production13 ponds13 golf-shy‐course13 ponds and natural floodplain-shy‐wetlands The majority of

razorback suckers that are stocked come from13 six major production facilities Bubbling

Ponds State13 Fish13 Hatchery13 The Grand13 Valley13 Endangered13 Fish Facility13 and13 Dexter13 Ouray13

Willow13 Beach13 and Uvalde National13 Fish Hatcheries13 Tables 2-shy‐313 outline13 the13 types13 of fish

holding facilities and water quality conditions that exist at each of these main production

locations A brief summary of procedures for rearing razorback suckers at each of these

facilities13 follows

These summaries are based on interviews conducted with hatchery personnel in July 2007 during site visits

This information13 is provided only to give a brief overview of razorback grow-shy‐out procedures Please verify13

accuracy13 of specific information with individual hatchery managers

10

13

Table13 1 List of locations13 that have13 been13 used to13 grow-shy‐out razorback suckers

$$amp ()amp$+ ($ampamp$+( $amp()$+ $amp()amp+(-0(12(342056( )0(-75amp8(95amp( 0$$05(lt==gt( 5amp+(amp4amp(Aamp+amp050+(12(14$6( 5amp+(amp4amp8(B$5+( B7$(lt==lt8()C0C05(lt===8(D0$05(0($(lt==E8(amp2F(0($(lt==E(

GltHI5+(342056J( K0L05(Damp$(12(342056( K0L058(D0M(0L4( N$055(lt==E( FF(-0(12(342056( D05(9$F8(B$5+( -42amp5(amp+($amp(lt==lt( OP0(0+(342056( $+05(B68(D0Q+( N-R(lt==gt( S56(Damp$(12(342056( D05(T05amp$8(N2( B7$(lt==lt8(U5Qamp(0($(lt==H8()C0C05(0($(lt==E8(0$$05(lt==gt8(N-1V-(WXXX( NQ$+0(Damp$(12(342056( NQ$+08(Y0L( N-R(lt==gt( V2M07(12(342056( M058(N2( B7$(lt==lt8(Qamp(amp+(5+M42(lt===( V$$M(042(Damp$(12(342056( 0$M(3Q05(KF(amp(B$5+(RQ058(95amp( 3ampamp(WXXgt( 942(3amp6( D05()5P058(95amp( N-1V-(lt==Z( --+-0+-12-3(4-5 )005(7amp+( 5amp+(amp4amp8(B$5+( Y2+(amp2F8(705amp$(4FFamp4amp( ltgt(5+(7amp+( 5amp+(amp4amp8(B$5+( )C0C05(0($[(WXXX( amp+(7amp+(( 5amp+(amp4amp8(B$5+( )C0C05(0($[(WXXX( B$6F05()amp+( BampC$0amp40(C(B$5+(amp+(ampampamp( )C0C05(0($[(WXXX8(B7$(lt==lt( B$5+(I(W](++amp$($00+(7amp+( 5amp+(T$$068(B$5+( )C0C05(lt===( KP0(5+(7amp+( 5amp+(T$$068(B$5+( )C0C05(0($[(WXXX( 32$amp0(7amp+( 5amp+(T$$068(B$5+( )C0C05(0($[(WXXX( 35020C(505amp(7amp+( 5amp+(amp4amp8(B$5+( )C0C05(lt===8(B7$(lt==lt( 0-6-3+ $620(Famp47$($C(450( $6208(B$C5amp( ^50amp($C(450_(9-N(R00542()5P( 08(95amp( 52(WXXH8(52(WX]( )0($C(450(7amp+( )08(95amp( 0$$05(amp+(V4P(WXX]( 768639 0amp(50(DVR( -2(C(Y4amp8(95amp( 52(WX]( B$(32(O0Q00()amp+( B$(Damp$(V$+$C0(R0C08(D05($6208(B$C5amp( 52(lt===8(amp4P$06(amp+(O55(WXXX8(0$$05(lt==gt( SQ05amp(M$+$C0(amp0F0amp(50( D05(OP0(0+(ampC$M8(D0Q+( N-R(lt==gt( -0amp5(V2( D52(C(`F8(95amp( ^5042Fampamp(amp+(O0$0(lt==gt8(amp4P$06(amp+(O55(WXXX( )1(+ KQ(4Q0( OP0(2Q08(95amp( 0$$05(WXXlt8(0$$05(amp+(5P0(lt==Z( 95amp(aQ0amp$0( OP0(2Q08(95amp( -$56(WXX]( -2(-+0Mamp+05( OP0(2Q08(95amp( -$56(WXX]( `F(BQ0( OP0(2Q08(95amp( 0$$05(WXXlt8(0$$05(amp+(5P0(lt==Z( Kamp+6( OP0(2Q08(D0Q+( -$56(WXX]( D52(B20F020Q0( OP0(2Q08(D0Q+( -$56(WXX]( D52(X($0( OP0(2Q08(D0Q+( Y6(V$05(N-R8(705amp$(4FFamp4amp( V$$M( OP0(2Q08(D0Q+( Y6(V$05(N-R8(705amp$(4FFamp4amp( D0Q+(A( OP0(2Q08(D0Q+( Y6(V$05(N-R8(705amp$(4FFamp4amp( D0Q+(O5Q0( OP0(2Q08(D0Q+( Y6(V$05(N-R8(705amp$(4FFamp4amp( 0+58lt+--457(5 9Q0(50ampampamp( D05(T05amp$8(N2( )C0C05(0($[(lt==E( ampamp(5+0( D05(T05amp$8(N2( )C0C05(0($[(lt==E( 2ampamp(F( D05(T05amp$8(N2( ++0(amp+(3amp0(lt==Z( O0(W=( D05(T05amp$8(N2( N-1V-(WXXX( O0(F( D05(T05amp$8(N2( ++0(amp+(3amp0(lt==Z( S$+(425$06(V2( D05(T05amp$8(N2( ++0(amp+(3amp0(lt==Z8(++0(WXXgt( O00+(7amp+(amp(20(Namp2(amp( D05(T05amp$8(N2( U5Qamp(0($(lt==H8()C0C05(0($(lt==E( =($+ 1$6+(OF(0(75P(GY0$0(75ampJ( O(T08(D0Q+ (52(WXXH( Y5amp++(-0(amp5(B$$00( 9$F8(B$5+( -42amp5(amp+(Oamp(lt==lt( 5MI(7amp+( D05(15Fampamp8(D( -42amp5(amp+(Oamp(lt==lt(

11

13

Table 2 Facilities available at major razorback sucker fish hatcheries

$amp( )$+(-+( 0(1(2$amp3amp(( 4-56+ amp7(8-+1$(9+( lt3-5( 8=$33( 23gt(805(

$amp()amp+(-(012345( 0(0+amp(A(BBCC(05 ampD(ED F CGBH IACCCACCC BJH K$+L(0D

amp$+(M$gt$ O-$+(+($P

B N B

CGBH IACCCACCC BABHC FANCC

BJH

Qamp+-3$+($P F FHC 637134(801amp0$(-(012345( H(L$33gt($O-amp1+(gt33A(

BCCC(05 ampDRK$+L(0D amp$+(M$gt$ M$-3$+($P Qamp+-3$+($P Qamp+-3$+($P

9O-$+amp$

SF S BC SC HC TC

CGI((IGC( HAHCC HSC IBC BCC IC

9O-$+amp$ BC SC 940amp+(amp21amp(8013(-(-02$15( U-ampamp0$3(D+ampPamp(gt$+ Qamp+-3$+($P IS VCC IB

W+Lamp1(+$+amp(0D( E-50D(+ampX+(gt$+( Qamp+-3$+($P JT BCC H K$+L(ED T CGBH(Y(CGH(

lt405(801amp0$(-(012345( J(L$33gt(gt33A(FCC(05( ampD(0D BS CGIBH(Z(CGBH( IC Qamp+-3$+($P NC IBC H Qamp+-3$+($P BJ VCC IC((IH

=$$gt(302(801amp0$(-(012345( 3$+(L$D(Q3+$D( MampX+(gt$+( amp$+(M$gt$ N IAHCC

amp$+(M$gt$ IF IFACCC 9O-$+amp$ FC IC

0$+3(801amp0$(-(012345( B([0(9O-amp1+()33A( IHCC(05 ampD(0D II I

K$+L(0D amp$+(M$gt$ amp$+(M$gt$

NJ B IB

GBH(Y(IGC( FAHCC IACCC

Qamp+-3$+($P Qamp+-3$+($P

IB N

BCC NACCC

12

13

Table13 3 Water13 quality13 ranges13 at each13 culture facility$amp ($)$++) -+$

-)amp012$)32$45 -6+)01763865 9$01-+3lt5 =amp+)01gt+39+5 $amp()amp+ ++)$6)+01A5

J gtLNL01O5 8P$ampamp401O5 ($Q+

BC3DE DD3DF BG3DB KLM3MLE KLH3MLI KLH3MLF CLM3BFLE CLM3BFLE CLM3BFLE

RQS0Aamp$ RQS0Aamp$ RQS0Aamp$ )ampQTamp$ )ampQTamp$ )ampQTamp$

8+)$O(6+T$ 8+)$ 8+)$ A6$)amp A6$)amp A6$)amp

BH3BI KLH3MLE CLM3BFLE

RQS0Aamp$ )ampQTamp$ 8+)$ A6$)amp

-01 ++)$6)+01A5 J gtLNL01O5 8P$ampamp401O5 ($Q+

BK3DE DD3DM BK3DE KLC3MLC KLC MLC DLM3GLK DLM3GLK DLM3GLK BIC3BMM BIC3BMM BIC3BMM

2ampamp$03040UQ$0amp0)6Q0amp0UampQ0ampamp0VampQ

BE3BI KLC

DLM3GLK BIC3BMM

213amp+(4amp50amp ++)$6)+01A5 J gtLNL01O5 8P$ampamp401O5 ($Q+

DH3DC DH3DC DH3DC KLK3MLE KLK3MLE KLK3MLE KLE3KLC ILC3KLE ILE3ILC BEE BEE BEE

+0$0amp+amplt+066)+0V$ampamp4S0RQ0$0)TP0T

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Bubbling Ponds State13 fish Hatchery13

Bubbling Ponds Fish Hatchery in Arizona does not maintain razorback sucker

broodstock on site Razorback suckers are received either as juveniles from13 Willow Beach

National Fish Hatchery13 or as13 newly-shy‐hatched larvae from13 Dexter13 National Fish Hatchery

Larval fish are13 typically13 placed13 into13 an unfertilized unlined 0613 acre13 pond13 in the13 spring In

September the pond is harvested by draining the pond and seining All fish that have

reached the target size (300 mm TL) are stocked Fish that are too small to stock are split

up equally between the six remaining grow-shy‐out pond at an13 average13 density13 of about 5000

ndash 7000 fish per pond Fish are fed by hand at approximately 25 body weight split

between morning and evening feedings Fish are either fed a catfish diet made by Rangenreg

13

13

that is enriched with spirulina and krill or razorback sucker diet made by Silvercupreg

depending on availability Fish are monitored visually and by sampling using a cast net

When a large number13 of fish have13 grown to13 the13 target size they13 are13 harvested13 by13 draining

the pond and seining13 Fish are again13 sorted by hand and the largest13 fish are stocked13 Fish

that13 have not13 reached the target13 size are returned to the ponds for further grow-shy‐out13 On13

average it13 takes one to two years for fish to reach the target13 size with fish growing13 an

average of 06 mmday Target numbers for production are 12000 razorback suckers

annually (300 mm TL) The biggest difficulty in rearing razorback suckers at Bubbling

Ponds13 Fish Hatchery13 is protozoan13 parasite13 infestations13 (Ich) and13 associated13 bacterial

infections that come from13 an open spring source that is inhabited by mosquitofish

Dexter National Fish Hatchery13

Dexter National Fish Hatchery maintains four separate razorback sucker13

broodstocks13 These fish are spawned on13 site and larval13 fish are placed directly into 01 acre

ponds at a density13 of about 20000 larvae13 per pond (50 ndash 100 thousand13 per13 acre)13 Ponds

are fertilized with alfalfa13 pellets and superphosphate two weeks prior to receiving13 larvae to

produce13 natural13 feed for larval13 fish13 Ponds are13 fertilized again with alfalfa13 pellets one week

after larvae are introduced13 Fish are fed a catfish starter diet13 (sizes 1-shy‐3) made by Rangenreg

that13 is enhanced with spirulina13 and krill13 and then switched over to the razorback13 diet13 once

they are large enough to eat 1mm13 crumble Fish are fed twice a day by hand four days a

week13 at 25-shy‐60 body weight Feed ration is decreased if excess feed is seen remaining

on the13 pond bottom13 following feedings Fish are not graded or sorted during this grow-shy‐out

period Razorback suckers are harvested in the fall by draining ponds completely Fish are

sorted13 at harvest and13 distributed13 to13 other13 facilities13 for further13 grow-shy‐out depending on13

current size requirements Razorback suckers are on average 100 ndash 200 mm TL after the

first growing13 season13 and13 generally13 take13 1 -shy‐18 months for a majority of the fish to reach

300 mm TL There are 16 different species of fish maintained at Dexter National13 Fish13

Hatchery13 and13 having sufficient pond13 space13 to13 grow out separate13 groups13 of fish is the13

limiting factor for production of razorback suckers at this location

14

13

Grand Valley13 Native13 Fish Facility13

The Grand Valley Native Fish Facility maintains its own brood stock13 in13 eight13 ponds

located at the Horsethief Basin Wildlife Area in Grand Junction Colorado Fish are

spawned13 on site13 and13 larvae13 are13 reared13 indoors in fiberglass13 tanks13 at the13 24-shy‐Road13 Fish13

Hatchery13 in Grand13 Junction The 24-shy‐Road13 Hatchery13 consists of two13 separate13 recirculating13

systems that operate using de-shy‐chlorinated13 city13 water13 and two13 large13 fluidized-shy‐ bed sand

filters13 and13 rotating-shy‐drum13 filters for waste removal Fish are held in 4-shy‐foot (n=78) or 8-shy‐foot

(n=14) diameter fiberglass tanks Larval fish are started on prepared feeds immediately

after swim-shy‐up and fed exclusively razorback feeds made by Silvercupreg Fish are started on

a 0-shy‐250 micron razorback diet for the first 10-shy‐1213 days13 and13 then13 fed with13 gradually13

increasing13 feed sizes based13 on observations of feeding13 (250 ndash 400 micron 1 starter) Feed

sizes are mixed when transitioning to the next larger feed size These razorback diets are

specially sifted by Dr Rick Barrows (USDA13 Hagerman experiment station Idaho)

Razorbacks13 are13 typically eating 1mm13 extruded pellets by the time they are 35 to 4 inches

in length Fish are fed approximately 70 body weight per day initially and then gradually

reduced to 15 body weight by the time they reach the 300 mm TL target size Fish are

fed seven days13 a week using13 12-shy‐hr13 belt feeders It takes13 12-shy‐16 months to grow fish to the

target13 size in13 the hatchery13

Razorback suckers are sorted after three months and culled to about 4000 fish per

family lot Culled fish are stocked into leased grow-shy‐out ponds Stocking densities for

juveniles in these ponds is based on previous13 stocking and harvest13 rates13 and is pond

specific13 Grow-shy‐out ponds are13 harvested13 periodically13 using Fyke13 nets13 or trap13 nets13 and13 fish of

the target size are stocked Disease problems (Ich Lernea) water quality problems (low

DO) and difficulty in removing all of the fish are challenges for grow-shy‐out of razorback

suckers13 in these13 natural ponds13

Fish reared13 in the13 24-shy‐Road facility are sorted again at four to five months of age into

small and large size groups to obtain more uniform13 growth rates Batch estimates of fish

weight are done every month for each tank A group of fish are weighed and counted to

give an average weight for the tank with lengths estimated based on a lengthweight chart13

The biggest difficulties13 for growing13 out razorback suckers13 at the13 24-shy‐Road13 Fish13 Hatchery13 are13

insufficient space and water flow (oxygen) to grow fish to the target size At the Horsethief

15

13

Basin13 Ponds where broodstock13 are reared13 diseases such as Ich are problematic because

water is pumped directly from13 the Colorado River

Ouray13 National Fish Hatchery13

Ouray13 National13 Fish Hatchery maintains its own broodstock and13 spawns13 fish on-shy‐site13

Larvae are transferred from13 indoor hatching tanks to unfertilized 02 acre outdoor ponds

and stocked at densities 10000 ndash 20000 larvae13 per13 pond13 Even13 though13 outdoor13 ponds13 are13

covered with13 bird13 netting13 avian predators13 still get caught in the13 nets13 if they13 can see fish

Ponds are dyed blue13 as the13 fish grow to13 prevent avian predation13 While in the outdoor

ponds13 fish13 are13 fed a slow-shy‐sinking salmon diet made by Silvercupreg twice daily by hand

Amount of feed is based on periodic sample counts Fish are grown until late September at

which time temperatures require that all fish13 other13 than13 adult broodstock13 be13 brought

inside for the winter Ponds are drained completely and fish are sorted by hand Fish that

have reached the target size (300 mm TL) are stocked into the Green and Colorado Rivers

All remaining fish are moved indoors13 and13 held13 in three-shy‐foot (n= 30) or eight-shy‐foot (n=27)

diameter circular tanks On average it takes 12 ndash 18 months to grow fish to the 300 mm TL

at Ouray13 hatchery13

Razorback suckers are held during the winter in a recirculating system13 that

operates13 using13 two13 large13 fluidized-shy‐bed sand filters and a rotating-shy‐drum13 filter for solids

removal Fish are fed the Silvercupreg razorback diet using belt feeders There is currently

capacity13 to13 hold13 only13 20000 200-shy‐300 mm TL fish inside the facility and any extra fish13 are13

stocked13 into13 floodplain-shy‐wetlands or used for research purposes13 Ouray no longer leases

any private grow-shy‐out ponds Grow-shy‐out ponds were troublesome due to poor water quality

harvesting13 difficulties13 and13 non-shy‐native13 fish introductions13 The biggest difficulty13 for

production13 of razorback13 suckers at the Ouray13 National13 Fish13 Hatchery13 is space13 during13 the

winter to maintain large numbers of fish and high iron and manganese in the well water

that must be filtered out prior to use

16

13

Willow Beach National Fish Hatchery13

Willow13 Beach National13 Fish Hatchery receives wild-shy‐caught larvae from13 Lake

Mohave Larvae are treated for diseases with formalin and malachite green and placed in

45 ten-shy‐gallon13 flow-shy‐through aquaria13 Recirculated13 solar heated water13 22-shy‐25deg C is used to13

allow production of warm13 water fish at this traditionally cold water facility (Figiel 2003

Figiel et al 2005) Fish are fed brine shrimp nauplii to satiation every hour and after 14

days small amounts of specialized larval fish diet (Encapsulon13 Cyclopeeze13 spirulina13 and

artificial plankton) are introduced After 30-shy‐6013 days13 fish are13 transferred13 to13 six13 32-shy‐gallon13

fiberglass troughs at densities of 1000 to 1500 fish per tank and then a month later moved

outside13 to13 eight recirculating13 raceways that use a combination of well water and solar-shy‐

heated water to maintain temperatures of 22 ndash 25deg C during the summer months

When13 in13 the outside raceways13 fish are fed the razorback13 diet13 using13 belt13 feeders and

fed by13 hand13 at 10 -shy‐ 70 body13 weight per13 day Feed amount is adjusted based on sample

counts according to a feed conversion program13 developed for razorback suckers by Willow

Beach Hatchery personnel This program13 uses length and number-shy‐per-shy‐pound generated

from13 several years of razorback growth data (Figure13 1) Fish are13 sorted13 opportunistically13

and are not handled during the summer months when water temperatures are above 20degC

In 2004 the target size for stocking was 325 mm TL or greater (WBNFH 2004) with a

target13 of producing13 6000 fish per year Reaching this13 target size usually13 takes13 two13 growing13

seasons13 The biggest difficulty13 in rearing13 razorback suckers13 at Willow Beach13 National Fish

Hatchery13 is insufficient space13 to13 grow fish to13 increased13 target sizes (400-shy‐500 mm TL)

Uvalde13 National Fish Hatchery13

Uvalde13 National Fish Hatchery13 in Texas13 receives 35000 ndash 60000 razorback sucker13

fry annually in MarchApril from13 Dexter National Fish Hatchery The fry are acclimated in

bags submerged in the pond for a minimum13 of one hour and released into13 a 1 acre13 fertilized13

pond where they are reared for the remainder of the summer Fingerlings are fed a starter

razorback diet when they reach approximately 50 mm TL In AprilMay the previous year

class of razorbacks are captured from13 their over-shy‐wintering pond enumerated graded and

split into13 one-shy‐acre grow-shy‐out ponds Approximately 4000 ndash 5000 fish will be13 placed13 in each13

one acre pond for summer grow-shy‐out Fish are reared for approximately 150 days (May ndash

17

13

Oct) and fed the Bozeman razorback diet two times a day five days a week at 15 ndash 30

body weight per day based on average water temperature

Figure 1 Relationship between length and number of fish per pound

In general13 juvenile razorback13 suckers (received as fry13 during13 the previous spring)13

reach the target size of 300 mm TL in approximately 6 months In 20062007 Uvalde

produced 6000 razorback suckers 300 mm TL for introduction into the San Juan River

Starting13 in 2008 Uvalde NFH will be producing13 and distributing13 12000-shy‐ 300 mm TL

razorbacks for stocking into the San Juan River Predation from13 migrating cormorants has

occurred but timing of harvest and over wintering protection methods such as covering

ponds with netting or placing fish indoors helps to minimize losses during the cormorant

migration (November to March) Uvalde has experienced razorback mortalities because of

bacterial problems but these are usually resolved through the use of oxytetracyline

medicated feed

Overview13 of Differences in Culture Methods

Several differences were noted when conducting surveys at each of the five main

production facilities for razorback sucker (See Appendix 3) These differences include

different stocking13 and13 rearing13 densities13 (Table13 4-shy‐5) various feeding regimes and type of

18

13

lt=amp

feeds (Table 7) as well as differences in grading or sorting practices Some of these

differences are13 related13 to13 whether13 or not razorback suckers13 are13 being13 reared13 in extensive-shy‐

culture13 facilities13 (ponds) or intensive-shy‐culture13 settings13 (raceways13 o tanks)13 Some13 practices13

are unique to a single facility13 or a couple of facilities (Table 6)13 Managers at each facility13

were asked to identify the biggest13 difficulty or constraint13 that13 they experience when13

growing-shy‐out juvenile13 razorback suckers13 at their13 respective13 location13 Space constraints13

water quality and disease problems were the main factors limiting production of razorback

suckers13 at these13 facilities13 (Table13 8) Calculated or reported growth rates from13 the literature

vary widely (Table 9) and range from13 02 to 18 mmday These growth rates indicate that

juvenile razorback suckers have a very high growth potential under optimal rearing

conditions13

Table13 4 Stocking13 densities13 for larvae13 and13 fry in ponds

$amp( )(+amp-( 01-2(3(4amp56( 4amp56(+amp-( 01-2782-( $amp () + --amp +amp0amp)+amp 12-3amp ( )+amp0amp+amp --amp +amp0amp)+amp 42556789amp8 ( +amp0ampgt+amp 3amp +amp0amp+amp A-BC-Damp (E + 3amp )+ F-6ltamp ) G+ 3amp G+

Table13 5 Rearing13 densities13 at intensive13 culture13 facilities13

$amp( )amp+(($-( $0( 12(3$+( 40((amp05( 67((amp05( 8$9(407$( $amp amp())amp++-$amp 0 1 0amp2amp1amp 3amp2amp4 0544

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6amp())amp++-$amp 610 77amp2amp1amp 0amp2amp1amp 053

19

13

Table13 6 Rearing13 practices13 that are13 unique to13 specific rearing13 facilities13 $$amp( )$+-(amp$-(0(1-amp2034( $amp()amp+( -0$(12(33+(amp(amp134$53+(amp$amp3+(6amp+(

723(843(1$8(422(6amp+(42amp(4(423(19$43( 343( lt34$53(6amp+(6(4($03(amp4+94amp(842($1$1(63$$34(amp+(63626243( =amp+(gtamp94ampA( B3(1(1$+53+C3+(amp+(1$43(1(3D0$(1(amp443(amp+(amp443( 734231(amp( B3(1(193(44(1(34amp(amp(+49E(6amp+( -E3(F3+( G3amp(1(12(amp(H3(13$(4ampE(C(IJK($$amp( A( L43(+A3(4(6303amp4(63+4ampM(66$3D3amp4$(34amp(amp(6amp+(C((4amp3( L$$8(392(

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Table13 7 Types of feed used at razorback sucker13 hatcheries13 $amp ()amp+-amp0- $$)1amp23 45-amp)-$5)1amp23 $amp()amp+( -amp$amp+(amp+( -amp012$3+(amp+4(amp5215$(0+( 65ampamp7(85209(+2($1(87((15315lt=(+2(

+amp+amp(amp(55$5$2gt( 21( Aamp+(amp+( )amp+(012$3+(B29(5$05$95($$2(5amp+(

199524(amp5215$(0+( 65ampamp7(85209(+2($1(87(15315lt=(+2(amplt( 29gt(51($51(amp9(2(25=(C(DD(0+(

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$1(87(15315lt=(+2(D5$$(3(lt5$$gt(02+(gt( 6lt=(511B(

L15gt( G1$5(lt1lt$51(25amp=(Aamp+( amp+(

HIJKH(Dlt1amp(15315lt=(+2(I(C2(CH(+5gt( )11$gt($511(02+(15315lt=(+2(

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M$$B(5lt9(-5$+( NO515(G1$5(219( L2+1(15ltB5gt(Aamp+(5amp+( amp$amp+(amp+(

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$1(87(15315lt=(+2($1(87(15315lt=(+2( $1(87(15315lt=(+2(

Table 8 Factors limiting production at major razorback sucker facilities

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Table9Reportedandcalculatedgrowthratesfromtheliterature

Calculatedgrow

thratesbasedon

informationprovidedinliterature

aApproximationsofmaximum

grow

thpotential(basedon

average13 maximum

sizesiffishreportedatharvest

21

13

General Information on Factors that Affect Fish Growth

Growth in fish is extremely variable and is impacted by many different

physiological and environmental factors Growth rates are known to change with size and

age sex season activity level density amount13 of living space quality and quantity of food

genetics and temperature (Brett 1979) Growth experiments conducted at different times

of year can result in growth rates that are not comparable As fish become larger their

physiological13 potential to grow decreases making determination of growth rate dependent

on the size of the starting fish and the length of the experiment (Busacker et al 1990)

Genetic factors also have great potential to influence growth rate Some species have

strains13 and13 races13 that display vastly different growth potentials (Reinitz et al 1979) All of

these factors combine to make assessment of the individual factors controlling fish growth

difficult13

Water temperature is probably the most important variable affecting growth rate13

All of the basic functions that affect growth such as feeding digestion and metabolism are

temperature-shy‐dependent13 Growth13 is inseparably13 tied13 to13 bioenergetics13 and13 therefore13 also13

tightly tied to temperature When temperatures are below optimum daily temperature

fluctuations can stimulate growth Photoperiod is also commonly linked to water

temperature and can influence growth rates in fish (reviewed in Brett 1979)

Fish density13 is known to13 affect growth13 and13 can alter13 growth13 rates13 in several ways13

Fish that exhibit strong territorial behaviors13 or natural schooling tendencies13 will

experience reduced growth if densities are too high or too low (Brett 1979) Dominance

hierarchies where some fish feed more aggressively than others can also lead to high

variability13 in growth13 rates13 (Koebele13 1985) Crowded13 conditions13 also13 cause physical

interference13 between13 fish and13 poor water13 quality13 which13 reduces13 growth13 (Busacker13 et al13

1990) The effects of fish numbers space and feeding opportunity are frequently correlated13

and often13 difficult13 to distinguish (Brett13 1979)13

It is impossible to study the effects of environmental factors on growth without also

evaluating feed rations (Brett 1979) Amount of food quality of the diet particle size

number of feedings per day and time of feeding have all been shown to affect growth

(Busacker et al 1990) In controlled laboratory studies food is usually fed ad libitum13

22

13

(constantly available) and other variables are altered to assess impacts of environmental

factors13 on growth13 These studies13 are13 usually13 conducted13 in tanks13 or raceways13 because13

researchers must verify that food is constantly available to the fish which is difficult to do

in large pond environments where the fish and the bottom13 are often not visible (Busacker13

et al13 1990)

Specific Information13 o Razorback13 Sucker13 Growth

Variable13 growth

Growth in razorback suckers is naturally highly variable and may be a function of

their evolutionary history (USFWS13 2002)13 Minckley (1983) speculated that13 wide size

variation in a single cohort of razorback suckers may be adaptive with fast-shy‐growing13 fish

that13 reproduce at a young13 age surviving13 better in13 high discharge years and slow-shy‐growing13

smaller fish surviving better during drought periods This highly variable growth rate

makes rearing razorback suckers in a production setting difficult because fish from13 a single

cohort do not reach the target stocking size simultaneously One of the major tasks for

aquaculture is to maximize both individual growth and total production13 (Gerking13 1978)13

This becomes more difficult when the species being cultured exhibits highly variable

growth13 rates13 because of genetic influences as is the case with razorback13 suckers13

Razorback13 sucker growth13 is typically very13 rapid13 during13 the first13 year of life13 and then13

declines with age First year growth can be as low as 50 mm and as high as 350 mm (Valdez

et al13 1982 Minckley13 1983 Mueller13 1995) Razorback sucker13 grow rapidly13 for

approximately the first five or six years of life and then growth slows13 (McCarthy13 and13

Minckely 198713 Tyus 199813 Minckley et13 al 1991)13 Growth of older individuals in13 extant13 wild

populations is very13 low (Minckley 198313 Tyus 198813 Modde13 et al 1996)13 Wild growth13 rates

for mature adult fish in Lake Mohave based on PIT tag recaptures were often too small to

be accurately measured for both males and females over the time period of 1987-shy‐199713

(Marsh and Pacey 1998) This information suggest it will take substantially longer to rear

fish to13 increasingly13 larger13 stocking13 sizes (40013 ndash 500 mm TL) than it did to reach the target

size of 300 mm TL

Growth in ponds

23

13

One of the main strategies for maintaining genetic refugia and self-shy‐sustaining13

populations of razorback13 sucker in the lower Colorado13 River basin13 is to rear razorback13

sucker13 larvae13 in production13 ponds until they13 are13 a suitable13 size for stocking13 (USFWS13 2004)

Pond culture has proven useful to promote rapid growth of juvenile razorback suckers

(Kaeding and Osmundson 1989) Marsh (1994) reported that growth rates of razorback

suckers13 reared13 in golf-shy‐course13 ponds exceeded13 the13 best growth13 rates13 obtained13 under

intensive13 culture13 conditions13 at federal hatcheries13 especially13 during the13 first several years13

of life Growth rates in these semi-shy‐natural ponds are also comparable to estimated growth

rates13 of juvenile13 wild13 fish (McCarthy13 and13 Minckley13 1987) Modde13 and13 Haines13 (2005)

reported13 the13 greatest growth13 rates13 in the13 largest and13 deepest floodplains13 with13 the13 greatest

amount of submergent vegetation but excellent growth and survival of fish in a grow-shy‐out

pond is of little value if there is not an efficient way to collect the fish from13 the pond

(Kaeding and Osmundson 1989)

Temperature13

Bulkley and Pimentel (1983) used shuttle boxes in the laboratory to determine a

temperature preference13 for razorback suckers13 of 23-shy‐24degC13 In13 their13 studies13 razorback

suckers were found to avoid temperatures below 118 degC or above 286 degC Razorback

suckers at Bubbling Ponds Hatchery are more active in the spring and feed better as

photoperiod increases even prior to water temperatures rising (Frank Agygos personal

communication) Table 3 briefly summarizes water temperature data from13 each facility

Detailed seasonal water temperature profiles are not currently available for many

razorback grow-shy‐out sites13

Density13

Extensive studies have been conducted on commercially important species to

evaluate stocking densities and feeding rates that maximize production For these species

controlled experiments under laboratory conditions have established relationships

between temperature density and feed ration on growth (Brett 1979) but this information

is sporadic13 or non-shy‐existent for razorback suckers13 (Bays13 et al13 2005) Fish culturists13 with13

24

13

experience13 rearing13 razorback suckers13 typically13 have13 target stocking13 densities13 that13 they use

(Tables13 4 -shy‐ 5) These stocking densities have largely been determined over time by trial

and error These approximate stocking densities provide a good starting point for more

controlled13 types13 of replicated13 pond studies13

Feed ration

Razorback13 suckers are currently13 being13 fed a wide variety13 of prepared diets (Table 7)

that range from13 a slow-shy‐sinking salmon feed manufactured by Silver Cupreg to a spirulina

and krill-shy‐enhanced catfish feed made by Rangenreg Most locations are feeding 20 ndash 50

body13 weight per13 day13 Methods13 for culture13 of razorback sucker13 larvae13 in intensive13 settings13 at

fish hatcheries are well documented (Figiel 2005) and various larval fish diets have been

evaluated13 (Tyus and13 Severson 1990 Severson et al13 1992) but no standardized13 procedures

are used for feeding13 larval13 fish in13 intensive settings13

Razorback sucker larvae are also effectively reared in pond environments using

natural foods supplemented with larval fish diets and survival is high when no predators

are present13 (Mueller 2006)13 Growth rates for larval13 and early juvenile razorback13 suckers

may increase with pond fertilization Diet and physiological studies on wild razorback

suckers indicate that they feed on plankton as well as benthic organisms during their entire

life (Marsh 1987) Artificially fertilizing ponds may greatly increase production capacity

and growth rates for razorback13 sucker (Papoulias and Minckley13 1992) and warrants

further13 investigation13

Handling stress

Handling stress13 has13 been shown to13 influence growth13 rates13 Paukert13 et al (2005)

found that growth of bonytail chub was reduced by 26when compared with controls

after being13 repeatedly13 captured and handled in13 hoop13 nets13 Handling13 effects are likely13 to be

similar for razorback suckers that are repeatedly13 captured and sorted in13 a hatchery13 setting13

Razorback suckers that are handled at Willow Beach National Fish Hatchery will commonly

not eat for two weeks after handling (John Scott personal communication) This creates a

difficult situation13 for production13 facilities because13 fish13 need to be sorted to ensure13 large13

25

13

aggressive fish do not interfere with growth of smaller individuals but frequent handling

and sorting13 causes stress related reductions in13 growth13

Measuring Growth in Captive Fish

Weight is the traditional measure used to estimate growth or production in

aquaculture settings13 Groups of fish are typically13 weighed and an average individual13 weight13

is computed (Busacker et al 1990) Although this method is often logistically the easiest it

may not be the most informative for species with highly variable growth rates like

razorback suckers especially when target lengths must be reached before fish can be

stocked Weight can also be highly influenced by things like stomach fullness or

development of gonads (Busacker et al 1990) Condition factor or relative weight can also

be used to assess growth of fish but these tools may be more robust predictors of fecundity

than of growth (Anderson and Neuman 1996) For some species sexes need to be

distinguished because males and females may differ in morphology (Anderson and

Neumann 1996) Mueller (2006) analyzed growth rates based on PIT tag recaptures of 86

razorback suckers13 in High13 Levee Pond13 and13 found13 that differences13 in growth13 do not appear13

to occur until fish are over 450 mm TL at which time growth rate in males slows while

females continue to grow at a slightly higher rate This would indicate that sex may not be

an important factor to consider when examining growth rates unless the target grow-shy‐out

size is above 450 mm TL

The best measures of growth are often determined from13 the length and weight of

individuals rather than from13 groups of fish (Anderson and Nuemannn 1996) because

individual growth rates give better estimates of confidence and variance (Busacker et13 al

1990) Length frequency analysis or recapture of previously marked individuals of a known

size is likely to yield the most useful information for razorback sucker growth The success

of any of these methods depends on proper sampling procedures that are representative of

the population as a whole (Busacker et al 1990) Sampling methods that are known to be

size-shy‐biased such as trammel nets (Mueller et al 2004) or cast nets should not be used when

trying to measure growth rates13

26

13

Conclusions

For razorback sucker survival is largely associated with stocking size Additional

focused13 research13 is therefore13 needed to13 identify13 ways13 to13 increase13 growth13 rates13 of captive-shy‐

reared13 razorback sucker Growth13 rate13 in fish is controlled13 by many factors including fish

size and age temperature density and feed ration which can all be highly correlated

Growth of razorback suckers is also inherently variable which makes the task of identifying

the key factors that13 affect13 growth in13 captivity even more difficult The focus at most

razorback rearing facilities13 is production so the13 types13 of data that are13 collected13 are13 often

insufficient for detailed13 evaluations13 of individual rearing13 practices13 on growth13 Surveys of

existing13 razorback sucker13 rearing facilities indicate that culture methods vary widely and

the types of growth data13 that13 are collected are not13 standardized13 Replicated studies with

detailed information on rearing location water temperature initial stocking size stocking

density and the sizes of all fish at harvest are needed in order to compare the effects of

individual rearing practices on growth This type of research will ultimately provide both

time and cost-shy‐savings to production facilities by reducing the amount of time necessary13 for

razorback sucker to reach stocking size improving overall production efficiency

Optimum13 rearing densities for razorback sucker larvae and juveniles remain to be

determined Current stocking densities will be very useful as starting point for more

detailed studies and although optimum13 rearing densities are likely to be site-shy‐specific13

replicated studies on density will provide a valuable reference for hatchery managers

Frequency13 of sorting is another13 area that needs13 further13 research Frequent

handling13 and13 sorting13 can13 cause13 stress-shy‐related13 reductions13 in growth but not sorting can

create dominance hierarchies that further reduce growth rates of subordinate individuals

The effects13 of sorting13 on overall fish growth13 in both13 pond and13 intensive13 culture13

environments warrant further investigation Research techniques for these types of

experiments are well understood and typically utilize a matrix of replicate ponds per

variable (Bays et al 2005) In every case accurate and complete records of sampling

procedures and data collection are needed in order to interpret data and make inferences

about13 growth rates (Busacker et13 al 1990)13

27

13

Additional research is also needed to evaluate long-shy‐term13 survival of stocked fish

reared in ponds compared to fish13 reared13 in intensive13 culture13 facilities13 Exercise13

conditioning13 and predator-shy‐recognition training may also increase survival of stocked fish

and be more economically feasible than rearing fish to increasingly larger sizes prior to

stocking13 The success13 of traditional fish hatchery programs is measured largely by the

number of fish stocked but hatchery programs for endangered species must measure

success in terms of long-shy‐term13 survival and species recovery (Brannon 1993 Anders 1998)

A specific list of research recommendations follows

Specific Research13 Recommendations13

bull Use replicated studies13 to establish optimum stocking13 densities13 for ponds13 and

tanks13 that can be used as13 a starting13 point for site specific refinement

bull Determine if sortinggrading13 improves13 overall growth rates13 in both ponds13 and

intensive culture facilities13

bull Investigate the use of artificial fertilizers13 to improve growth of both juvenile

and adult razorback suckers13 in ponds13

bull Determine if the razorback sucker diet gives13 better growth rates13 than cheaper

catfish or salmon feeds

bull Evaluate growth rates13 and production potential of new intensive culture

methods13 such as13 large circular tanks13

bull Evaluate13 long-shy‐term survival of fish produced from raceways13 and circular tanks13

compared to fish reared in ponds13

bull Evaluate more effective means13 of treating13 fish diseases13

bull Evaluate factors13 other than size that may increase post-shy‐stocking13 survival such

as13 exercise conditioning13 predator recognition training or rearing13 under more

natural settings13

28

13

II The Effect of Disease Treatments on Razorback Sucker

Growth

Section13 SummaryFormalin copper sulfate potassium permanganate and13 salt are all chemicals commonly13 used13 to13 treat13 Ichthyophthirius multifiliis outbreaks in captive razorback sucker (Xyrauchen13 texanus) Weexposed 190 juvenile13 razorback suckers (127 ndash 26 mm TL) to13 5 5-shy‐day treatments with13 each13 chemical to evaluate the effects13 these chemicals13 may have on growth Fish grew an average of23513 mm TL13 during the month13 study period Fish treated with formalin grew on average13 29mm TL (03 mmday) while fish treated with copper had the lowest growth averaging 20 mmTL (021 mmday) No significant differences in13 growth were observed among fish treatedwith any of the chemicals compared to untreated fish (pgt005) Reductions in growth13 as aresult of repeated chemical treatments are not likely the cause of differences in growth ratesamong13 facilities that raise razorback suckers Repeated chemical treatments may13 have otherimpacts to overall13 fitness or long-shy‐term survival but13 these effects were not13 evident13 in our study

29

13

Introduction

Preservation13 of razorback sucker13 (Xyrauchen texanus) currently13 depends on captive13

rearing and stocking programs until permanent solutions to factors that prevent wild13

recruitment are found Low survival of stocked razorback suckers (Brooks 1986 Marsh

and Brooks 198913 Marsh and Pacey13 2005) has caused target13 sizes for stocked fish to

steadily increase in efforts to reduce predation mortality (Marsh et al 2005 Schooley and

Marsh 2007) Rearing fish to larger sizes at hatcheries comes with increased costs and

creates the need to evaluate husbandry and rearing practices that may affect fish growth

Formalin copper sulfate potassium13 permanganate and salt are all chemicals

commonly used at razorback sucker rearing facilities to treat outbreaks of the protozoan

parasite13 Ichthyophthirius multifiliis ldquoIchrdquo is one of the most pathenogenic diseases of

cultured13 freshwater13 fishes (Matthews13 2005) and causes large13 losses in captive13 populations13

of endangered razorback sucker Each of these chemicals used to treat Ich only kill the free-shy‐

swimming life stage of the parasite13 requiring13 repeated doses over several13 days depending13

on water temperature These chemicals treatments are needed to prevent loss as a result

of disease outbreaks but the cumulative effects repeated disease treatments have on

growth13 are13 unknown

Copper13 sulfate13 has13 been shown to13 significantly13 reduce13 growth13 of channel catfish13 in

production13 ponds (Rabago-shy‐Castro13 2006) but it is unknown whether13 razorback suckers13

experience similar reduced growth following copper treatment Quantifying the impacts of

disease treatments on growth will help to interpret the wide differences in growth rates

observed13 at various13 razorback sucker13 production13 facilities13 throughout the13 southwest

(Ward et al 2007) If one chemical is found to have less detrimental impacts on growth

than another then it may be preferred for use as a disease treatment We evaluated growth

rates13 of razorback suckers13 under13 replicated13 and13 controlled13 conditions13 to13 assess13 effects13 of

repeated formalin copper sulfate and potassium permanganate and salt treatments on

growth13

Methods

We captured 190 juvenile razorback suckers from13 ponds at Bubbling Ponds Fish

Hatchery AZ using hoop nets or cast nets All fish were of the same age class and

30

13

averaged 179 mm total length (TL) (range13 = 127 ndash 262 mm TL)13 These fish were13 offspring13

of captive13 razorback sucker13 broodstock held13 at Dexter13 National13 Fish Hatchery13 NM13 (2007

year class) All fish were tagged with passive integrated transponder (PIT) tags and

quarantined for one month prior to the experiment to allow fish to recover from13 tagging

and become accustomed to being held in circular tanks

At the beginning of the study all fish were weighed measured and scanned for

individual tag numbers with 19 randomly selected fish placed into each13 of 10 8-shy‐foot

diameter circular tanks (Figure 2)13 Each13 tank contained13 two13 airstones13 and13 an13 individual

biofilter with a recirculating water pump (31 litersminute) that had been operating for

at least 1 month prior to the experiment to allow bacterial colonies to become

established Two tanks were designated as a control and did not receive any chemical

treatments while the other eight tanks received formalin copper sulfate potassium13

permanganate or salt treatments at two week intervals (two tanks per chemical

treatment) Formalin copper sulfate and potassium13 permanganate were treated at 1 part

per million (ppm) and salt was applied at 30 parts per thousand (ppt) These treatment

rates are commonly used to treat13 razorback13 suckers for ich at Bubbling13 Ponds Fish13

hatchery (Frank Agygos personal communication)

Figure 213 Photo ofexperimental tankswith individualbiofilters and aeration

31

13

Each treatment consisted of a series of doses applied on Wednesday Thursday and

Friday with a 90water change between each dose Biofilters were removed from13 all

tanks and held in a separate holding facility during treatments and then replaced on the

Monday following treatments after a 90water change This schedule allowed fish to be

exposed to chemical treatments for 5 consecutive days without water quality deteriorating

This 5-shy‐day chemical treatment was repeated every two weeks from13 July to October (97

days)13 for a total of 5 5-shy‐day treatments Water temperature in the treatment tanks ranged

from13 13degC (55degF) to 32degC (91degF)

Fish were fed a fixed ration of commercial razorback diet (Silvercup 4mm13 pellet)

once daily13 (2 percent body13 weight per day13 as calculated13 by13 average initial fish weight)13

At the end of the experiment all fish were again weighed measured and scanned for

individual tag numbers Growth of fish in each treatment group was compared using

analysis of variance (ANOVA) Any mortalities13 that occurred during the13 study13 were13

replaced with previously quarantined fish of equivalent size to maintain equal densities in

each13 tank13 but growth13 data was13 only13 recorded for fish which13 survived13 the13 entire13

experiment

Results

Fish at the13 start of the experiment averaged 179 mm TL (Range13 = 127 ndash 262 mm)

with no significant differences in fish length among treatment groups (F(4189) = 00183 p

gt 0999 ANOVA) On average fish grew 235 mm TL (024 mmday) during the 3 month

study13 Fish in tanks13 treated with formalin had the highest growth averaging 29 mm TL (03

mmday) while fish in tanks treated with copper had the lowest growth averaging 20 mm

TL (021 mmday) Fish in the control tanks averaged 213 mm TL in growth (022

mmday) (Figure13 3)13 Formalin-shy‐treated fish grew13 significantly faster than13 any other

treatment group but no13 significant differences in growth13 in length13 or weight were13

observed among fish treated with any of the chemicals compared to untreated (control)

fish (pgt005 ANOVA)

32

13

Figure 313 Average growthof razorback suckersexposed to a series of 5 5-shy‐day chemical treatmentsover a 97-shy‐day13 periodError bars representstandard error

Discussion13

Growth13 rates13 observed13 in our study13 (021 ndash 03 mmday) are low compared to those

reported13 in other13 studies13 of razorback sucker13 growth13 (0213 ndash 18 mmday) (Ward et al

2007) Using recirculating water systems for our study required filters to be removed and

replaced during treatments Stress to fish caused by removing and replacing filters within

the tanks as well as repeated water changes may have led to overall higher stress and

reduced growth rates compared to those reported for unconfined fish Growth in fish is

highly variable and is affected by many different physiological and environmental factors

including fish size density temperature amount of space and food (Brett 1979) We

strived to control each of these factors but other factors may have also influenced growth

in our experimental tanks During mid-shy‐summer water temperatures in the treatment

tanks reached 32degC (91degF) At these warm13 temperatures fish are very susceptible to

bacterial13 infections13 The slightly higher growth exhibited by fish in the formalin and

potassium13 permanganate treatments may have been the result of these two chemicals

33

13

being effective at controlling bacterial infections The differences in growth we measured

among treatment groups were not statistically significant and do not appear13 biologically13

meaningful during the relatively short duration of this study (97 days) although the

cumulative effects of slightly reduced growth could be biologically meaningful over longer

time frames

Reductions in growth13 as a result13 o repeated chemical treatments are not likely the

cause of differences in growth rates among facilities that raise razorback suckers

Repeated chemical treatments may have other impacts to overall fitness or long-shy‐term13

survival but these13 effects13 were13 not evident in our study It is more likely that the parasite

outbreaks themselves are the cause of different growth rates among razorback rearing

facilities rather than the chemical treatments used to treat the parasites We recommend

that hatchery managers continue to use the chemicals that are most effective at controlling

ldquoIchrdquo13 at their individual13 facilities

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower Colorado Rive Multi-shy‐species13

Conservation Plan under Work Task C10 We thank Ty Wolters and Tom13 Burke for their

support of this research and Frank Agygos and Dave Billingsly of the Bubbling Ponds Fish

Hatchery13 for their13 technical assistance13 and13 help with13 collecting13 fish

34

13

III13 Razorback Growth Rates at Bubbling Ponds ndash 2009-shy‐2011

Section13 SummaryExperimental studies at Bubbling Ponds Fish Hatchery AZ have strived to understand

factors that affect razorback sucker growth in captivity and identify ways to improve growthrates and maximize size at release Rather than performing experimental studies that wouldrequire major13 rearrangement (and likely reduced production)13 of hatchery operations our13 studies13 used normal variation in production techniques13 and practices13 to isolate factors13 thatmay modify growth rates

Our initial work identified razorback13 growth rates in13 lined ponds at standard fishdensity as 026 to13 028mmday (789 to 843 mmmonth) No significant differences in growthrate were observed among fish that had been in the pond only during the winter13 periodcompared to fish that had been in the pond the entire year indicating that water temperatures13 at Bubbling Ponds are high enough to allow fish to incorporate feed effectively year-shy‐roundHowever these growth rates are lower than most values reported from the literature fromnatural or semi-shy‐natural pond environments No significant differences in13 growth rate wereobserved13 between large and13 small fish13 within the 150 ndash 29 mm TL13 size range Additional worksuggests13 that razorback suckers13 tagged at over 300 mm TL had reduced growth rates (024mmday 73 mmmonth) as would be expected according to a typical Von13 Bertalanfy growthcurve although growth rates13 were only slightly less13 than the average growth rate for thehatchery (027513 mmday 82513 mmmonth)

Sorting13 to13 separate small fish from large fish after the first year of growth is practicedesigned13 to allow smaller fish to ldquocatch uprdquo to larger fish We found that13 this technique doesappear to13 improve growth rates of smaller fish Growth rates of sorted small razorback suckers(029 mmday 87mmmonth)13 were equal to that13 of larger13 fish (028 mmday 8413 mmmonth)indicating that sorting may have helped to offset their original slower growth trajectory

Bubbling Ponds Fish Hatchery grows razorbacks in 6 long deep ponds lined with heavyplastic 2 long deep13 earthen13 (unlined) ponds and three wide shallow earthen ponds The wideshallow ponds13 have historically produced very large fish at low density but have been found tomaintain much lower fish numbers than deeper ponds We found13 that growth13 rates ofrazorbacks kept at high density (4-shy‐700013 fish)13 in a wide shallow pond grew extremely slowly(024 mmday 726 mmmonth) This growth rate is among the slowest of any fish over theyears of our study and demonstrates that13 though the large ponds may produce large fish at lowdensity13 they are unable to overcome high13 fish13 densities

Finally one of the major factors influencing13 fish13 growth13 in hatcheries is disease onemajor summer-shy‐time disease at13 Bubbling Ponds is the ectoparasite Ich (Ichthiopthirusmultifiliis) To investigate the impact Ich has on razorback growth we eradicated fish from thespring and water conveyance ditch that supplies13 water to the hatchery using Rotenone This13 restoration effort was fairly short-shy‐lived (Ich returned to the hatchery within four months) but

35

13

growth13 rates of fish13 reared for four months without Ich present (031 mmday 92 mmmonth)were significantly higher than the following 8 months of growth for those same fish (022mmday 65 mmmonth) This disease-shy‐free growth rate is in fact faster than any13 otherprevious growth rates observed at the hatchery in our study

We conclude that growth rates at the Bubbling Ponds Fish Hatchery are likely as highas possible given the pond densities required to13 meet production goals and the Ich-shy‐infestedwater13 that feeds the facility Sorting practices are successful in helping as many fish as possiblereach stocking length as fast as possible Unlined ponds may be able to grow large fish at lowdensities but whatever factors allow for that growth13 are not able13 to overcome13 high fish densityThus the large lower ponds at Bubbling Ponds may be better utilized via renovation to13 deepenand line them

Disease is the most important factor limiting growth as may be expected to be the caseat many13 hatcheries While the spring renovation was not13 a complete success13 the dramaticreduction of fish populations in that habitat was enough to dramatically13 reduce13 the13 occurrenceof Ich at the hatchery13 Such open spring13 systems feeding a hatchery are a misfortune that canbe expected to transmit disease so we suggest that renovating the spring again to combat13 IchImproved techniques to divert water from13 the springs and more throuough treatment ofstream-shy‐side vegetation may improve the success of chemical treatment Successful renovationwould likely both improve growth rates and reduce chemical costs associated with treating Ichoutbreaks Even13 if complete renovation13 is impossible or impractical an13 effort to reduceinvasive fish density in the springs13 which act a vector for the parasite(and thereby reduce thelikelihood of13 Ich being transmitted into ponds) may still13 show dramatic improvements

36

13

Introduction

Conservation efforts13 for razorback sucker13 (Xyrauchen texanus)13 currently13 depend on

captive rearing and stocking programs Low survival of stocked razorback suckers (Brooks

1986 Marsh13 and13 Brooks13 1989 Marsh13 and13 Pacey13 2005) has13 caused13 target sizes for stocked13

fish to steadily increase in efforts to reduce predation mortality13 (Marsh13 et al13 2005

Schooley and Marsh 2007) Rearing fish to larger sizes at hatcheries comes with increased

costs and creates the need to evaluate husbandry and rearing practices that may affect fish

growth13 We evaluated growth13 rates13 of individual razorback suckers13 in ponds13 at Bubbling

Ponds Fish Hatchery13 using Passive Integrated13 Transponder (PIT) tags13 to13 obtain13 precise

growth information for individual fish so that valid comparisons of growth rates as related

to rearing practices can be made

Due to the critical nature of the razorback sucker stocking program we did not

design experimental studies that would require major rearrangement and potentially

reduce production of hatchery operations Instead our studies used normal variation in

production techniques and practices to isolate factors that may modify growth rates

Though this methodology dramatically limits replication and may limit our ability to

directly13 attribute13 differences in growth13 rates13 to13 the13 variables13 we13 investigate13 we13 were13 able13

to accomplish research goals without altering hatchery operations or impacting

production

From13 2009 through 2011 we conducted a series of observational13 growth13 studies to

determine growth rates of individual razorbacks at Bubbling Ponds The first set of

experiments included13 identifying13 growth13 rates13 in lined13 and13 unlined13 ponds determining

growth13 rates13 of fish at different13 sizes13 in13 relation13 to sorting13 practices and monitoring

razorback growth rates after removing the source of the ectoparasite13 Ich (Ichthiopthirus

multifiliis) from13 the hatchery water source13

Razorback growth rate in lined ponds

Our first growth study documented individual growth rates at normal density in 11

million gallon lined ponds13 over two13 years13 This is the standard13 grow-shy‐out process for

razorbacks13 at Bubbling Ponds We monitored growth of fish for a variety13 of sizes and13 the13

37

13

amount of time in a pond during the growing season These13 data give a snapshot of growth13

rates13 at the13 facility13 and13 provide13 the basis for comparisons throughout our study

Growth rate13 in an unlined pond

In addition13 to 6 ponds lined with heavy plastic13 sheeting13 Bubbling Ponds Fish13

Hatchery maintains two narrow and deep (same dimensions as lined ponds13 Figure13 4)13 and13

three large13 shallow unlined ponds These earthen13 ponds typically have vegetation and

associated aquatic invertebrates that may better simulate natural environments by

providing cover and improved food diversity or quality Therefore these unlined ponds

may be expected to produce higher growth rates and potentially improved survival that is

more similar to growth rates observed in more natural grow-shy‐out facilities13 Historically13 the13

large13 shallow13 ponds have produced very large fish when13 utilized at low13 fish density13 The

narrow13 deep earthen13 ponds are13 used to grow13 fry13 at high density in their first13 year of life

The major downside to unlined ponds is the difficulty in harvesting fish where a lined

pond might take 8-shy‐1013 people13 a half13 day13 to13 harvest13 lined13 ponds13 require13 intensive13 weeding13

to allow seines to be pulled and therefore require many more personnel-shy‐hours13 In addition13

to harvest challenges the shallow earthen ponds tend to suffer from13 dissolved oxygen

crashes during the summer Unlined ponds also may maintain higher13 populations13 of non-shy‐

target species such as bluegill sunfish mosquito fish and bullfrog tadpoles We measured

growth rates of suckers in a large shallow earthen pond for comparison to growth in lined

ponds13

Figure13 4 Lined13 and13 earthen ponds13 of similar dimensions (approx 1000000 gallons first

and second panels) and a large13 shallow13 earthen13 pond (third panel)

38

13

Effect of sorting on growth

Razorback13 suckers13 are13 currently13 sorted13 after their first13 year of growth13 They are13

typically removed from13 one of the13 upper earthen13 ponds and13 split into13 two13 lined13 ponds for

subsequent grow-shy‐out13 The larger13 fish (gt approximately 140 mm) are placed into one pond

and the smaller individuals in another It is possible that the larger fish were more

aggressive or adept13 at taking food so this sorting process is intended to allow smaller fish

to improve their growth rate

Effect of Ich on razorback sucker growth rates

We13 evaluated13 growth13 rates13 of razorback sucker13 in the13 presence13 and absence of the

ectoparasite13 Ich (Ichthiopthirus multifiliis) Ich outbreaks can occur in wild populations13 but

hatcheries13 have13 proven excellent locations13 for Ich because13 of very high fish densities13 which13

facilitate13 the13 transfer13 of Ich13 between13 fish This common fish parasite causes direct mortality13

to razorback13 suckers as well13 as secondary bacterial13 infections13

The open spring and13 ditch13 which13 provides water to the Bubbling13 Ponds Hatchery

has long13 been infested with mosquitofish (Gambusia affinis) that harbor13 the13 Ich parasite13

and allow13 it13 to enter the hatchery with incoming13 water13 The solution13 to13 the13 Ich problem13

was to remove the mosquitofish host using13 Rotenone Razorback13 sucker growth13 rates were13

then tracked in13 the absence of this parasite for 4 months and compared with growth rates

after Ich returned to the pond and from13 previous years

Methods

Razorback growth rate in lined ponds

On May 14 2008 141 razorback suckers were tagged with 12 mm PIT tags (1342

kHz) and placed in Pond 3 (approximately 1100000 gallons13 Figure13 4)13 at Bubbling13 Ponds

Fish Hatchery Fifty-shy‐three of these tags were recovered two months later when a large

Ichthyophthirius multifilis (Ich) outbreak killed many fish in the pond On October 15 2008

an additional13 145 PIT tagged13 fish were13 also placed into Pond13 3 On13 May13 14 2009 Pond13 3

was harvested and a total13 of 141 PIT tagged fish were recovered13 Of the tagged fish13 26 fish

had13 been13 in the13 pond since May13 of 2008 (378 days13 o growth) and 115 had been13 in13 the

39

13 40

pond since October13 15 2008 (211 days13 of growth) Numbers of fish in Pond 3 after the Ich

outbreak and for the majority of the period of growth were between 3 000 and 4000 fish

A Hobotempreg temperature13 logger13 was13 also13 installed13 in Pond 3 one meter below the water

surface13 near13 the13 outflow and13 recorded water temperature every 3 hours to allow analysis

of the effects of water temperature on growth rate (Figure13 5) This Hobotemp data is

representative of other pond temperatures throughout this study

In a second experiment 210 adult13 razorback suckers13 were13 PIT tagged13 on13 May 14

2009 and13 placed13 into13 Pond13 3 upper to13 evaluate13 growth13 rates13 of larger13 razorback suckers13 at

Bubbling13 Ponds Hatchery13 under current13 rearing13 conditions13 Size of these fish at tagging13

was (mean = 285 mm range = 205 ndash 396 mm) These fish remained in the pond for 257

days and were harvested on Jan 25 2010 to provide information on growth rates of larger

razorback suckers13 under13 current rearing conditions

Figure 513 Temperatures (degC) inrearing pond at BubblingPonds Hatchery from July toSept 2009 (top graph)13 andfrom Nov to Dec 2009 (Lowergraph) Temperaturesrecorded with a Hobotempregremote data logger13 every 3hours

13

Growth rate13 in an unlined pond

To document razorback sucker growth in earthen ponds we introduced13 225 tagged13

razorback suckers13 into13 Pond13 1 lower13 (Figure 4) in February 3 2010 Additional tagged fish

from13 other studies were added to the pond throughout the growing season and the density

of 1 lower reached a maximum13 of nearly 7000 fish in early summer 2010 Density was

reduced to approximately 6000 fish by capturing fish with hoop nets on June 3 2010 54 of

these fish were tagged fish and returned to 1 lower after being weighed and measured The

pond was harvested on January13 2713 2011 and a total13 of 254 tagged fish out13 of 4296 fish

total were removed from13 the pond The pond was harvested on January 27 2011 (358 days13

of growth) and the tagged fish were weighed and measured Total number of razorbacks in

the pond at harvest13 was 4296

Effect of sorting practices on growth rates

On March 1113 200913 Pond13 5 upper was13 harvested13 and13 split into13 two13 separate13 groups

Two hundred of the smaller fish (average size = 122 mm TL) were PIT tagged and placed

into13 Pond13 7 upper and13 200 of the13 larger13 fish (average = 160 mm TL) were PIT tagged and

placed int Pond13 8 upper Density13 in Pond13 7 was13 4500 fish and13 in Pond13 8 there13 were13 6500

fish These ponds were then harvested after 1 year and growth rates were compared to

give information on the effects of current sorting practices Hobotempreg temperature

loggers were installed in13 Ponds 7 and13 8 during13 the13 grow-shy‐out period with13 water13

temperature recorded every 2 hours13 (Figure13 6)

Effect of Ich on razorback sucker growth rates

Bubbling Ponds spring was treated with Rotenone (CFT Legumine 5) at a

concentration of 2 ppm13 to remove all mosquitofish from13 the spring The treatment

consisted of two treatments 6 hours in duration on two consecutive days (April 12 -shy‐ 13)

using13 drip13 stations13 and13 backpack sprayers13 followed13 by13 an13 additional 6 hours13 of

detoxification using sodium13 permanganate Although 12 mosquitofish were captured in the

spring pond the week following the treatments subsequent minnow trapping (20 traps

checked13 daily13 for 3 weeks) did not capture any additional fish until August 11 2010 when

41

13

juvenile mosquitofish were again detected in the spring pond Minnow traps have

subsequently been set daily with several hundred individuals removed To evaluate if Ich

was also again present in the spring we captured 15 mosquitofish from13 the spring pond on

three separate days and placed them13 in an aquaria at 25 degC with 5 longfin dace known to be

free of Ich These fish were monitored for 2 weeks with no signs of Ich developing This

indicates that even though mosquitofish have returned to the spring pond the parasite is no

longer present13 although how13 long13 this condition13 will13 persist13 is unknown13

On May 1113 201013 200 juvenile razorback13 suckers were harvested out13 of Pond 5

upper (2009 year Class from13 Dexter National Fish Hatchery) and were PIT tagged and

placed into Pond 8 to evaluate if growth rates at bubbling ponds hatchery have improved

following the renovation of the spring and the removal of the Ich parasite Unfortunately13

on Sept13 8 2010 Ich was13 again13 detected13 in Pond 8 and the pond was immediately seined

and 74 tagged fish were measured to obtain growth information for the 4-shy‐month period

during13 which13 the13 pond13 was13 Ich-shy‐free13

Figure13 6 Temperatures (degC) in rearingponds 7 and 8 at Bubbling Ponds Hatchery13 from March 2009 ndash March 201013 pond 7(top13 graph)13 and13 pond 8 (Lower13 graph)13 Temperatures recorded with a Hobotempregremote data logger every 3 hours

42

13

Results

Growth in Lined Ponds

Razorback suckers13 that had been13 in13 Pond 8 upper for the13 entire13 year13 grew an13

average of 0263 mmday (789 mmmonth) and razorback suckers that had been in the

pond for 7 months (Oct -shy‐ May) grew13 on13 average of 028 mmday (843 mmmonth) (Figure13

7) These growth13 rates13 did not significantly13 differ Fish density13 in Pond 3 during13 the13

majority of the growth period was13 00032 ndash 00036 fishgallon13 Additionally no13 significant

differences in growth rate were observed between fish smaller than 210 mm TL and fish

larger than 210 mm TL when all recaptured fish were combined

We also measured the growth rate of very large fish in a lined pond On Jan13 2513 201013

156 adult fish with PIT tags were recovered from13 Pond 3 upper13 These fish were13 in the13

pond for 257 days and experienced an average13 growth13 rate13 of 024mmday or 73

mmmonth (Figure13 7)13 This growth13 rate13 is slightly13 lower13 than13 the13 average13 growth13 rate13

observed13 at Bubbling13 Ponds Hatchery in other studies (0275 mmday 825 mmmonth)

but may not be biologically meaningful We would expect larger13 fish to13 have13 reduced

growth rates according to a typical Von Bertalanfy growth model (Bertalanffy 1957) but it

appears that13 over the size range we evaluated (300 -shy‐ 450 mm TL) growth rates have not

slowed significantly compared to that of smaller13 fish grown at Bubbling Ponds13 Hatchery

Growth13 of razorback suckers13 is known13 to13 slow as13 fish reach13 larger13 sizes but it appears13 this13

reduced growth rate may not really start to be biologically meaningful at Bubbling Ponds

Hatchery13 until razorback suckers13 exceed 450 mm TL

Growth in unlined ponds

Growth13 rates13 for the13 fish recaptured13 during13 the Pond 1 lower13 thinning13 (120 days13 in

the pond) was 024 plusmn 003 mmday (729 plusmn 090 mmmonth) (Figure13 8)13 Fish13 that were13 in

the pond for nearly the entire year grew13 an13 average13 of 024 plusmn 001 mmday (726 plusmn 027

mmmonth) These growth rates are surprisingly the lowest measured growth rates for

any part of our study and differ significantly from13 every other measured growth rate

except very large13 fish (Figure13 9)13 Separating13 out13 large fish that13 were in13 the pond for the

entire year makes no difference fish that were added to the pond at TL lt300 mm grew

43

13

Gro

wth

Rat

e (m

md

ay)

020

026

032

0244 plusmn 001 mmday (733 plusmn 028 mmmonth) and and those with TL gt= 300 mm at the

start of the experiment grew 022 plusmn 003 mmday (651 plusmn 101 mmmonth)

Razorback Growth Rates in Lined Ponds

Figure 7 Growth ofrazorback suckers in(mmday plusmn standard error)in Pond 8 upper in 2008-shy‐2009 An ANOVA did notdetect any significantdifferences

7 Months Full Year 300+ mm fish

Effects of sorting on growth

One hundred and seventy five tagged razorback suckers were recovered from13 Pond

8 upper13 on March13 24 2010 (378 days13 of growth)13 These were13 the13 larger sorted13 fish (gt140

mm TL) that came out of Pond13 5 on March13 11 2009 One13 hundred and13 twenty13 two13 tagged13

razorback suckers were also recovered from13 Pond13 7 upper on March13 31 2010 (385 days13 of

growth)13 These were13 the13 smaller sorted13 fish (lt140 mm TL) that came out of Pond13 5 on

March 1113 200913 No significant differences in growth rate (mmday) were observed among

larger fish in Pond 8 and smaller fish in Pond 7 (pgt005 ANOVA) (Figure 10)13 indicating

that13 sorting may have helped to offset the original slower growth trajectory of the smaller

fish Temperatures of Ponds 7 and 8 upper remained similar throughout the year13 (Figure

5)

44

13

13

13

Gro

wth

Rat

e (m

md

ay)

Gro

wth

Rat

e (m

md

ay)

020

026

032

020

026

032

Razorback Growth in an Unlined Pond

Figure 8 Growth of razorbacksuckers (mmday plusmn standard error) in Pond 1 lower (an unlined pond)in 2010-shy‐2011 An ANOVA did notdetect any significant differences

6 Months 12 Months lt 300 mm Fish 300+ mm Fish Growth Growth

Lined vs Earthen Ponds 1 year of growth

Figure 9 Growth of razorbacksuckers (mmday plusmn standard error) in lined and unlined ponds A t-shy‐test13 did not detect a significantdifference

Lined Pond Unlined Pond 1 Yr Growth 1 Yr Growth

45

13

Effect of Sorting G

row

th R

ate

(mm

day

) G

row

th R

ate

(mm

day

)

032

020

026

032

020

026

Smaller Fish Larger Fish

Effect of Ich

Figure 10 Average growthof razorback suckers(mmday plusmn standard error)that were size-shy‐sorted intosmall fish (pond 7) and largefish (pond 8) populations At-shy‐test did not detect asignificant difference

Figure 11 Average growth ofrazorback suckers (mmday plusmnstandard error) after Ich wasremovd from the hatcheryrsquos springand after Ich was again detected inthe pond The growth rate withoutIch is significantly higher than boththe rate after Ich and the ourstudyrsquos average annual growth ratein lined ponds (ANOVA p =00003)

Growth without Ich Growth With Ich Average Annual 4 months 4 months Growth Rate

46

13

Effect of Ich on razorback sucker growth rates

Seventy-shy‐four13 tagged13 razorback suckers13 were13 recovered from13 Pond 8 on September

15 2010 These fish had13 been13 in the pond for 4 months and experienced a growth rate of

032 mmday or 97 mmmonth (Figure13 11)13 This growth13 rate13 is significantly higher (p =

005 two sample t-shy‐test) than the mean growth rate for the same group13 of tagged fish after

Ich detection (022 mmday or 65 mmmonth) and significantly higher than any other

individual growth13 rates13 observed13 to13 date13 at Bubbling13 Ponds Hatchery13 (Figure13 11)13 If this13

growth13 rate13 were13 extended throughout13 the entire13 year13 fish on average from13 Ich-shy‐free13 ponds13

would be 16 mm longer than fish from13 ponds infested with Ich Studies conducted at

Bubbling Ponds hatchery in 2008 (Ward 2008) did not reveal any effects of the treatment

chemicals on razorback sucker growth rates so it13 is likely that13 the parasite outbreaks

themselves are causing reducing growth rates rather than the chemicals used to treat the

parasites13

Conclusions

Our results suggest that under typical hatchery operations (maximizing number of

fish produced)13 the growth13 rate13 of razorback13 suckers13 is relatively13 consistent at Bubbling13

Ponds hatchery13 at 02-shy‐03 mmday (6-shy‐9 mmmonth)13 but is lower than growth13 rates13 at

other13 facilities (02 ndash 18 mmday Ward et al 2007)13 This growth13 rate13 has13 been13 constant in

both lined and unlined ponds and at all fish densities we were able to measure To achieve13

growth13 rates13 substantially higher than this will likely require13 significant changes in rearing

practices that may not be practical in order to reach numerical production13 goals

Temperature is a key variable in fish growth but seasonal growth patterns

described13 above13 (Figure13 5) demonstrate that water temperatures are high enough in

winter to maintain razorback growth Differences in water temperature by season

currently13 do not fluctuate more than 10degC at Bubbling Ponds because of the continuous

supply of water flowing through each pond (approx 225 gallonsmin) These high water

flows appear to keep pond temperatures within the thermal preference13 for razorback

suckers13 (1213 -shy‐ 28 degC Bulkley and Pimentel 1983) throughout the entire year with

temperatures rarely dropping13 below 16deg13 C (Figures 513 6)13

47

13

Fish density is another key variable in fish growth and though the number of fish in

a pond during our study ranged from13 3000 to 700013 fish we13 did not find any13 correlation13

between13 density and growth rate13 This might yield two conclusions First13 razorback

growth13 may be changed equally13 by13 densities13 at the13 hatchery13 (ie13 a density13 of 3000 fish in a

pond is as stressful13 for razorbacks as a density13 of 7000 fish) An alternative is that other

factors13 such as disease outbreaks have13 stronger13 control over fish growth13 than13 density13

Fish density13 would13 have13 to13 be13 experimentally manipulated to test13 this13 and hatchery

operations (producing the maximum13 number of fish) prevented our manipulating density13

in ponds for this13 work The trouble with manipulating density demonstrates the difficulties

associated with changing13 hatchery13 practices experimenting with density would have

prevented BPH from13 meeting13 production13 goals Given that the stocking of smaller

razorbacks has met with very little success perhaps BPH goals could be changed from13

producing 12000 fish at 300+ mm per year to a smaller number of very large fish each

year Growing13 fewer13 larger13 fish could potentially be accomplished in the same time frame

as more smaller fish but a better understanding of how density alters growth rate would

be required to be confident13 of this

The very slow growth13 in the13 earthen13 unlined13 Pond 1 lower13 was very surprising We13

had13 anticipated13 that the13 diversified diet13 cover and13 other13 habitat features13 provided by13

unlined ponds would yield dramatically increased growth rates However these traits were

not enough to offset high fish densities and in fact the unlined pond in our study13 suffered

mortality to bring densities down to that observed normally in lined ponds

Our data13 suggest13 that razorbacks13 sucker13 growth13 rates13 are13 higher in lined13 ponds13

However we13 think the reasons13 for the13 very slow growth we observed13 in the13 unlined13 pond13

in our study13 is instead13 linked13 to13 the13 usage13 of Pond 1 lower13 during13 the13 study13 rather13 than13

intrinsic13 slow growth13 in earthen13 ponds First the pond was at extremely high density for at

least part of the study The volume of Pond 1 lower has not been estimated but hatchery

managers suggest 1500-shy‐2000 fish is an appropriate number of individuals so this pond

was at a very high density for much of the experiment Second dissolved oxygen is often

very low in the13 large13 earthen13 ponds during the heat of summer much lower than that of

lined ponds This will both limit the number of fish that can survive in the pond and almost

certainly13 increases stress13 of these13 fish potentially13 reducing growth13 The DO crashes also13

48

13

limit the amount of feed hatchery managers can give fish in these ponds sometimes for

days or weeks at a time which further reduces growth during warm13 weather

Our data13 suggests that13 growth rates at the Bubbling13 Ponds Fish Hatchery are likely

as high as possible given13 the pond densities required to meet production goals and the Ich-shy‐

infested water that feeds the facility Sorting practices are successful in helping as many

fish as possible reach stocking length as fast as possible Unlined ponds may be able to

grow13 large13 fish at low13 densities13 but whatever factors allow13 for that13 growth are not13 able to

overcome high fish density The removal of invasive13 fis that act as13 a host for the13 parasite13

Ich fish from13 the Bubbling13 Ponds spring13 allowed the highest13 growth rate at 032 mmday13

(96 mmmonth) but that growth rate decreased again as Ich re-shy‐infested13 the13 hatchery13

Consistently13 achieving13 growth13 rates13 as high or substantially13 higher than13 this13 will likely13

require13 significant changes in rearing practices that may not be practical in order to13 reach13

numerical production13 goals

Two major changes that might result in higher growth rates are substantially

reducing fish density and modifying the way spring water is delivered to the facility (via

either repeated chemical treatments or enclosed concrete water diversions) to eliminate

Ich from13 the hatchery source water Other potential changes not address by our work

include13 flow-shy‐training razorbacks much previous literature including MSCP-shy‐funded13 work

on razorback suckers13 suggests13 that fish growing13 in flowing water will grow13 faster than fish

in still water (Jorgensen and Jobling 1994) Furthermore there are a wide variety of

potential benefits associated with growing13 fish13 in flowing13 water in addition13 to increased

growth13 rates13 (Davidson13 199713 Castro13 et al13 2011) Another option13 for increasing13 growth13

rates13 include13 changing to13 intensive13 culture13 in large circular13 tanks

Finally given that the stocking of smaller razorbacks has met with very little

success13 perhaps13 BPH13 goals13 could13 be13 changed from13 producing 12000 fish at 300+ mm per

year to a smaller number of very large fish each year Growing fewer larger fish could

potentially be accomplished in the same time frame as more smaller fish but a better

understanding13 of how density13 alters growth13 rate13 would13 be13 required to13 be13 confident of this

49

13

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower13 Colorado13 River Multi-shy‐Species13

Conservation Program13 (LCRMSCP) under Work Task C10 We13 thank Ty Wolters13 Tom13

Burke13 and Eric13 Volkman for their support of this research and Frank Agygos and Dave

Billingsly13 of the Bubbling13 Ponds Fish Hatchery13 for their willingness to participate in13 this

research13 and13 for their technical assistance We also thank the LCRMSCP fish group from13

Boulder City13 NV for their assistance with harvesting13 ponds and tagging13 fish13

50

13

Literature13 CitedAnders P J 1998 Conservation aquaculture and endangered species can objective science13

prevail13 over risk13 anxiety Fisheries 23(11) 28-shy‐31

Anderson R O and R M Nuemann 1996 Length weight and associated structural indicesPages 447 ndash 482 in B R Murphy13 and D13 W Willis13 editors13 Fisheries techniques13 2ndedtion American Fisheries13 Society13 Bethesda13 Maryland

Bain M B J T Finn and H E Brooks 1988 Streamflow regulation and fish communitystructure13 Ecology13 69382-shy‐392

Bays J H Zarbock R Whitman and T Murphy 2005 Conceptual design and managementof native13 fish refugia on the13 lower13 Colorado13 River In13 CL Spring13 and13 S Leoneditors Proceedings of two symposia Restoring native fish to the lower ColoradoRiver13 interactions13 of native and non-shy‐native13 fishes 13ndash1413 July13 1999 Las13 Vegas13 Nevada13 Restoring13 natural function within a modified riverine environment thelower Colorado River13 8ndash913 July13 1998 U S Fish and13 Wildlife13 Service Southwestern13 Region Albuquerque New Mexico Pages 167-shy‐177

Bertalanffy L Von 1957 Quantitative laws in metabolism13 and growth13 Q Rev Biology 32217 ndash 231

Bingham T B Scheer and C McAda 2003 Propagation facilities in Grand Valley (24 RoadHatchery Horsethief13 Ponds and13 grow-shy‐out ponds) for captive13 rearing13 ofendangered13 fishes for the13 upper13 Colorado13 River basin13 Colorado River RecoveryProgram FY2003 annual project report13 US Fish and13 Wildlife13 Service GrandJunction13 4pp

Birchell G J and K Christopherson 2004 Survival growth and recruitment of larval andjuvenile razorback13 sucker (Xyrauchen texanus) introduced13 into13 floodplain13 depressions13 of the13 Green River Utah13 Final report13 Upper13 Colorado13 RiverEndangered Fish Recovery Program13 Project No C-shy‐6RZ Publication Number 04-shy‐1513 Utah13 Division of Wildlife13 Resources Salt Lake13 City13 Utah13 67 pages

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Brett J R 1979 Environmental Factors and growth pages 599-shy‐67513 InW S Hoar13 D13 J13 Randall and J R Brett (eds) Fish Physiology Volume 8 Bioenergetics and GrowthAcademic Press New York

Brooks J E 1986 Annual reintroduction and monitoring report for razorback suckerXyrauchen texanus in the Gila River Basin Arizona 1985 US Fish and WildlifeService13 Offices of Endangered13 Species and Fishery13 Resources Albuquerque 23 pp

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Brunson13 R E and K D13 Christopherson13 200513 Larval13 razorback13 sucker and bonytailsurvival and13 growth13 in the13 presence13 of nonnative13 fish in the13 Baeser13 floodplainwetland of the middle Green River Final report prepared for Upper13 Colorado RiverBasin Endangered Fish Recovery Program Project No C-shy‐6-shy‐rz-shy‐bt Publication13 No 05-shy‐26 Utah13 Division of Wildlife13 Resources13 Vernal13 32 pp

Bulkley R V and R Pimentel 1983 Temperature preference and avoidance by adultrazorback suckers Transactions of the American Fisheries Society 112601-shy‐607

Burke13 T13 199513 Rearing13 wild razorback13 sucker larvae in13 lake-shy‐side13 backwaters13 LakeMohave ArizonaNevada Proceedings of the Desert Fishes Council 2635

Busacker G P I R Adelman and E M Goolish13 199013 Growth13 Pages 363 ndash 387 in C BSchreck and p B Moyle editors Methods for fish biology American FisheriesSociety Bethesda Maryland

Castro V B Grisdale-shy‐Helland S J Helland T Kristensen S M Jorgensen J Helgrud13 GClaireaux A P Farrell A Krasnov and H Takle 2011 Aerobic training stimulatesgrowth and promotes disease resistance in Atlantic salmon (Salmo salar)Comparative Biochemistry and Physiology -shy‐ Part A Molecular amp IntegrativePhysiology13 160(2) 278-shy‐290

Czapla T E 2002 Facilities plan for the production of endangered fishes to meet statestocking13 plans13 as13 part of the13 Upper13 Colorado13 River Endangered13 Fish RecoveryProgram Upper Colorado River Basin Recovery Implementation Program US Fishand Wildlife Service13 Denver13 9 pp

Davidson W 1997 The effects13 of exercise13 training on teleost fish a review of recentliterature Comput Biochem Physiol 117A67ndash75

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Hamman R L 1985 Induced spawning of hatchery-shy‐reared13 razorback sucker ProgressivFish Culturist 47(3) 187-shy‐189

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Kaeding L R and D B Osmundson 198913 Colorado13 Squawfish13 and13 razorback sucker grow-shy‐out pond studies as part of conservation measures for the green mountain andRuedi reservoir water sales Final report for agreement number 6-shy‐AA-shy‐60-shy‐00150

Koebele13 B P13 198513 Growth and the size hierarchy effect an experimental assessment ofthree proposed mechanisms activity differences disproportional food acquisition13 pysiological stress Environmental Biology of Fishes 12 181-shy‐188

Kretschmann A E and L L Leslie 2006 Razorback sucker (Xyrauchen texanus) status13 reproduction and recruitment in Senator Wash Reservoir CA Final Report13 to USBurea of Reclamation Cooperative Agreement No 00-shy‐FG-shy‐34-shy‐ 0009 p 32 ArizonaGame and Fish Department Phoenix

Marsh13 P13 C13 1987a13 Digestive tract13 contents13 of adult razorback suckers13 in Lake13 MohaveArizona-shy‐Nevada Transactions of the American Fisheries Society 116117-shy‐119

Marsh P C 1987b Native fishes at Buenos Aires National Wildlife Refuge and ArizonaState University Research Park Arizona opportunities for management researchand public13 education13 on13 endangered species13 Proceedings of the Desert13 FishesCouncil 1967-shy‐78

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Marsh P C B R Kesner and C A Pacey 2005 Repatriation as s management strategy13 to13 conserve a critically13 imperiled fish species North American Journal of FisheriesManagement 25 547-shy‐556

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Marsh13 P13 C13 and J13 E Brooks13 198913 Predation13 by ictalurid catfishes as a deterrent13 toreestablishment of hatchery-shy‐reared13 razorback sucker The Southwestern Naturalist34188-shy‐195

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Minckley13 C13 O and M LaBarbara13 199913 Report13 on13 native fish grow-shy‐out facilities13 at Cibolaand Imperial National Wildlife Refuges 1993-shy‐199513 US Fish and13 Wildlife Service13 Parker Fishery Resources Office Parker Arizona

Modde13 T13 199613 Juvenile razorback sucker (Xyrauchen texanus) in a managed wetlandadjacent13 to the Green13 River13 Great13 Basin13 Naturalist13 56375-shy‐376

Modde T KP Burnham and E J Wick 1996 Population status of the razorback sucker13 inthe middle Green River (USA) Conservation13 biology 10 110-shy‐119

Modde13 T13 and G13 B Haines13 200513 Survival13 and growth of stocked razorback13 sucker andbonytail in multiple floodplain wetlands of the middle Green River under resetconditions13 Final report prepared for Upper Colorado13 River13 Basin RecoveryImplimentation Program US Fish and Wildlife Service Vernal 66 pp

54

13

Modde T Z H Bowen and D C Kitcheyan 2005 Spatial and temporal use of a spawning13 site in the middle Green River by wild hatchery-shy‐reared13 razorback suckers13 Transactions of the American Fisheries Society 134937-shy‐944

Mueller13 G13 199213 The native fish work13 group13 -shy‐ a multiagency endeavor to improve thestatus of the razorback sucker in Lake Mohave AZ-shy‐NV13 Proceedings of the DesertFishes Council 2369

Mueller G 1995 A program13 for maintaining the razorback sucker in Lake MohaveAmerican Fisheries Society Symposium 15127-shy‐135

Mueller13 G13 200613 Ecology of the bonytail13 and razorback13 sucker and the role of offchannelhabitats13 in their13 recovery Scientific13 investigations13 report 2006-shy‐5065 US GeologicalSurvey13 Denver

Mueller G and E Wick 1998 Testing of golf course ponds at Page Arizona for suitability13 as grow-shy‐out facility for razorback sucker using surplus fish from13 Ouray NationalFish Hatchery National Park Service US Fish and13 Wildlife13 Service and UtahDivision of Wildlife13 Resources 28 pages

Mueller13 G13 and T13 Burke13 200513 Survival13 of young13 razorback13 sucker (Xyrauchen texanus) inrelation to13 stocking rates13 (fishha)13 and13 in the presence13 or absence13 of predatorcommunities in Lake Mohave Arizona-shy‐Nevada13 Pages13 155-shy‐16313 in Proceedings of two13 symposia restoring native fish to the lower Colorado River interaction13 of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 Nevada US Fish and Wildlife13 Service Southwest Region Albuquerque New Mexico

Mueller13 G13 J13 Carpenter13 and P13 C13 Marsh13 200413 Cibola13 High Levee Pond annual report 2004US Geological Survey Fort Collins13 Science Center13 Colorado13 and Arizona StateUniversity Tempe 23 pages

Nesler T P K Christopherson J M Hudson C W McAda F Pfeifer and T E Czapla 2003An integrated stocking plan for razorback sucker bonytail and Colorado13 pikeminnow for the Upper Colorado River Endangered Fish Recovery ProgramAddendum13 to State Stocking Plans Upper Colorado River Basin Recovery13 Implementation Program 12 pp

Papoulias13 D and W13 L Minckley13 1992 Effects13 of foo availability13 on survival and growth13 of larval razorback suckers13 in ponds Transactions of the American Fisheries Society121340-shy‐355

Paukert13 C P D L Ward13 P J Sponholtz13 and K13 D Hilwig13 Effects13 of repeated hoopnetting13 on bonytail chub13 Journal of Freshwater13 Ecology13 20(4) 649-shy‐653

Pfeifer F M13 C Baker13 and M13 Montagne13 199913 Propagation13 facilities13 in the13 Grand Valley13 (24 Road13 Hatchery13 Horsethief13 Ponds and13 grow-shy‐out ponds) for captive rearing of

55

13

endangered13 fishes for the13 Upper Colorado13 River Basin13 Colorado13 River Recovery13 Program FY 99 annual project report Project No 29a13 US Fish and Wildlife Service13 Grand13 Junction13 5pp

Pfeifer F S Seversen and M Montagne 2003 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2003 annual reportProject No 29b13 US Fish and Wildlife13 Service Vernal13 4pp

Rabago-shy‐Castro J L Sanchez13 J G Perez-shy‐Castaneda R and13 Gonzalez-shy‐Gonzlez A 2006Effects of the prophylactic use of Romet-shy‐3013 and13 copper13 sulfate13 on growth13 condition13 and feeding13 indicies in13 channel13 catfish (Ictalurus punctatus) Aquaculture 253 343-shy‐349

Reinitz GL L E Orme and F N Hitzel 1979 Variations of body compositio and growth13 among strains of rainbow trout Transactions of the American Fisheries Society 108204-shy‐207

Ruppert13 J13 B P B Holden13 and P D Abate 1999 Age estimation and growth of razorbacksucker13 Xyrauchen texanus in Lake13 Mead Nevada Proceedings13 of the Desert FishesCouncil 3040

Schnoor K D and J Logan 2002 Operation and maintenance of JW Mumma nativeaquatic13 species restoration facility Colorado Colorado River Recovery Program FY2002 annual project report13 Project No 29d Colorado13 Division of Wildlife Alamosa3pp

Salisbury13 L13 1998 Factors13 affecting razorback13 sucker growth13 in Lake13 Mohave backwaters13 MS Thesis13 Unviersity13 of Nevada13 Las13 Vegas

Schooley J13 D13 and P C13 Marsh13 2007 Stocking of endangerdd13 razorback13 suckers13 in thelower Colorado River Basin13 over three decades 1974-shy‐2004 North American Journalof Fisheries Management 27 43-shy‐51

Severson S H H M Tyus and G B Haines 1992 An evaluation of feeds for raisingrazorback sucker Xyrauchen texanus Journal of Applied Aquaculture 155-shy‐65

Toney D P 1974 Observations13 on the13 propagation13 and13 rearing13 of two13 endangered species13 in a hatchery environment Proceedings of the Annual Conference of the Western13 Association of State Game and Fish Commissions 54 252-shy‐259

Tyus H M13 1998 Razorback sucker13 (Xyrauchen texanus) recovery plan13 University13 ofColorado Center for Limnology Boulder13 76 pages

Tyus H M13 and13 S H Severson 1990 Growth13 and13 survival of larval razorback suckers fedfive formulated diets The Progressive Fish Culturist 52197-shy‐200

56

13

Ulibarri M E 2003 Annual report fiscal year 2001 Dexter National Fish Hatchery13 andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 26 pages

Ulibarri M E 2003 Annual report fiscal year 2002 Dexter National Fish Hatchery andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 59 pages

USBR 2006 Lower13 Colorado13 River Multi-shy‐Species Conservation Program final fishaugmentation plan Boulder City 19 pp

USFWS 2002 Razorback sucker (Xyraouchen texanus) recovery goals Amendment andsupplement to the Razorback Sucker Recovery Plan13 US Fish and Wildlife Service13 Region 6 Denver13 Colorado

USFWS 1999 Annual report 1999 Ouray National Fish Hatchery Vernal 25pp

USFWS 2004 Management plan for the big-shy‐river13 fishes of the13 lower13 Colorado13 river basinamendment and supplement to the bonytail humpback chub Coloradopikeminnow and razorback sucker recovery plans

USFWS13 2005 Station13 profile13 of the13 Dexter13 National Fish Hatchery13 and Technology CenterUS Fish and Wildlife13 Service Dexter

Valdez R A P G Mangan R Smith and B Nilson 1982 Upper Colorado River fisheriesinvestigations13 inW H Miller J J Valentine D L Archer H M Tyus R A Valdezand L13 Kaeding13 editors13 Colorado River Fishery13 Project13 Part 2 Field13 investigations13 US Bureau of Reclamation Salt Lake City Utah

WBNFH 2004 Culture methods of the endangered razorback sucker Xyrauchen texanusUS Fish and Wildlife13 Service Willow Beach National Fish Hatchery13 8 pp

Ward D 2008 Effects of disease treatments on growth of razorback sucker ReportSubmitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 Inpartial fulfillment of work task C10 agreement number 06FG30039

Ward13 D13 M Childs and W Persons 2007 Factors13 affecting13 growth13 of razorback sucker13 (Xyrauchen texanus) in captivity Literature review and knowledge assessmentReport Submitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 In partial fulfillment of work task C10 agreement number 06FG30039

57

Appendices

Appendix 1 Survey Questions Survey of Razorback Sucker Culture in the

Southwestern United States

The enclosed survey is being distributed by the Arizona Game and Fish Department to razorback sucker culture facilities throughout

the Southwestern United States The purpose of this survey is to consolidate information regarding culture of this species so that

appropriate facility improvements can be considered for Bubbling Ponds Hatchery in Arizona Specifically we wish to increase

growth rate and production efficiency at the hatchery Information gathered in this survey will be summarized in a final report to US

Bureau of Reclamation in Boulder City NV and disseminated to all facilities that participate in the survey A workshop to discuss

the findings of this study as well as to share general information concerning razorback sucker culture will be organized by the

Arizona Game and Fish Department at the conclusion of this study and all participants will be invited

Thank you for taking the time to fill out this survey Please contact Mike Childs if you have questions or would like to discuss the

survey

Mike Childs

mchildssedonanet

(928) 639-1346

(928) 634-1279

Facility_____________________________________ Date___________________

Contact Phone _____________________________

ContactPerson_______________________________

Contact Email _______________________________

1 Water quality ranges at this culture facility

Season

Spring (Mar-May) Summer (Jun-Aug) Fall (Sept-Nov) Winter (Dec-Feb)

Temperature (C)

PH

DO (mgL)

PO4 (mgL)

TDS (mgL)

Hardness (mgL)

CaCO3

Pathogens

37

13

Table13 1 List of locations13 that have13 been13 used to13 grow-shy‐out razorback suckers

$$amp ()amp$+ ($ampamp$+( $amp()$+ $amp()amp+(-0(12(342056( )0(-75amp8(95amp( 0$$05(lt==gt( 5amp+(amp4amp(Aamp+amp050+(12(14$6( 5amp+(amp4amp8(B$5+( B7$(lt==lt8()C0C05(lt===8(D0$05(0($(lt==E8(amp2F(0($(lt==E(

GltHI5+(342056J( K0L05(Damp$(12(342056( K0L058(D0M(0L4( N$055(lt==E( FF(-0(12(342056( D05(9$F8(B$5+( -42amp5(amp+($amp(lt==lt( OP0(0+(342056( $+05(B68(D0Q+( N-R(lt==gt( S56(Damp$(12(342056( D05(T05amp$8(N2( B7$(lt==lt8(U5Qamp(0($(lt==H8()C0C05(0($(lt==E8(0$$05(lt==gt8(N-1V-(WXXX( NQ$+0(Damp$(12(342056( NQ$+08(Y0L( N-R(lt==gt( V2M07(12(342056( M058(N2( B7$(lt==lt8(Qamp(amp+(5+M42(lt===( V$$M(042(Damp$(12(342056( 0$M(3Q05(KF(amp(B$5+(RQ058(95amp( 3ampamp(WXXgt( 942(3amp6( D05()5P058(95amp( N-1V-(lt==Z( --+-0+-12-3(4-5 )005(7amp+( 5amp+(amp4amp8(B$5+( Y2+(amp2F8(705amp$(4FFamp4amp( ltgt(5+(7amp+( 5amp+(amp4amp8(B$5+( )C0C05(0($[(WXXX( amp+(7amp+(( 5amp+(amp4amp8(B$5+( )C0C05(0($[(WXXX( B$6F05()amp+( BampC$0amp40(C(B$5+(amp+(ampampamp( )C0C05(0($[(WXXX8(B7$(lt==lt( B$5+(I(W](++amp$($00+(7amp+( 5amp+(T$$068(B$5+( )C0C05(lt===( KP0(5+(7amp+( 5amp+(T$$068(B$5+( )C0C05(0($[(WXXX( 32$amp0(7amp+( 5amp+(T$$068(B$5+( )C0C05(0($[(WXXX( 35020C(505amp(7amp+( 5amp+(amp4amp8(B$5+( )C0C05(lt===8(B7$(lt==lt( 0-6-3+ $620(Famp47$($C(450( $6208(B$C5amp( ^50amp($C(450_(9-N(R00542()5P( 08(95amp( 52(WXXH8(52(WX]( )0($C(450(7amp+( )08(95amp( 0$$05(amp+(V4P(WXX]( 768639 0amp(50(DVR( -2(C(Y4amp8(95amp( 52(WX]( B$(32(O0Q00()amp+( B$(Damp$(V$+$C0(R0C08(D05($6208(B$C5amp( 52(lt===8(amp4P$06(amp+(O55(WXXX8(0$$05(lt==gt( SQ05amp(M$+$C0(amp0F0amp(50( D05(OP0(0+(ampC$M8(D0Q+( N-R(lt==gt( -0amp5(V2( D52(C(`F8(95amp( ^5042Fampamp(amp+(O0$0(lt==gt8(amp4P$06(amp+(O55(WXXX( )1(+ KQ(4Q0( OP0(2Q08(95amp( 0$$05(WXXlt8(0$$05(amp+(5P0(lt==Z( 95amp(aQ0amp$0( OP0(2Q08(95amp( -$56(WXX]( -2(-+0Mamp+05( OP0(2Q08(95amp( -$56(WXX]( `F(BQ0( OP0(2Q08(95amp( 0$$05(WXXlt8(0$$05(amp+(5P0(lt==Z( Kamp+6( OP0(2Q08(D0Q+( -$56(WXX]( D52(B20F020Q0( OP0(2Q08(D0Q+( -$56(WXX]( D52(X($0( OP0(2Q08(D0Q+( Y6(V$05(N-R8(705amp$(4FFamp4amp( V$$M( OP0(2Q08(D0Q+( Y6(V$05(N-R8(705amp$(4FFamp4amp( D0Q+(A( OP0(2Q08(D0Q+( Y6(V$05(N-R8(705amp$(4FFamp4amp( D0Q+(O5Q0( OP0(2Q08(D0Q+( Y6(V$05(N-R8(705amp$(4FFamp4amp( 0+58lt+--457(5 9Q0(50ampampamp( D05(T05amp$8(N2( )C0C05(0($[(lt==E( ampamp(5+0( D05(T05amp$8(N2( )C0C05(0($[(lt==E( 2ampamp(F( D05(T05amp$8(N2( ++0(amp+(3amp0(lt==Z( O0(W=( D05(T05amp$8(N2( N-1V-(WXXX( O0(F( D05(T05amp$8(N2( ++0(amp+(3amp0(lt==Z( S$+(425$06(V2( D05(T05amp$8(N2( ++0(amp+(3amp0(lt==Z8(++0(WXXgt( O00+(7amp+(amp(20(Namp2(amp( D05(T05amp$8(N2( U5Qamp(0($(lt==H8()C0C05(0($(lt==E( =($+ 1$6+(OF(0(75P(GY0$0(75ampJ( O(T08(D0Q+ (52(WXXH( Y5amp++(-0(amp5(B$$00( 9$F8(B$5+( -42amp5(amp+(Oamp(lt==lt( 5MI(7amp+( D05(15Fampamp8(D( -42amp5(amp+(Oamp(lt==lt(

11

13

Table 2 Facilities available at major razorback sucker fish hatcheries

$amp( )$+(-+( 0(1(2$amp3amp(( 4-56+ amp7(8-+1$(9+( lt3-5( 8=$33( 23gt(805(

$amp()amp+(-(012345( 0(0+amp(A(BBCC(05 ampD(ED F CGBH IACCCACCC BJH K$+L(0D

amp$+(M$gt$ O-$+(+($P

B N B

CGBH IACCCACCC BABHC FANCC

BJH

Qamp+-3$+($P F FHC 637134(801amp0$(-(012345( H(L$33gt($O-amp1+(gt33A(

BCCC(05 ampDRK$+L(0D amp$+(M$gt$ M$-3$+($P Qamp+-3$+($P Qamp+-3$+($P

9O-$+amp$

SF S BC SC HC TC

CGI((IGC( HAHCC HSC IBC BCC IC

9O-$+amp$ BC SC 940amp+(amp21amp(8013(-(-02$15( U-ampamp0$3(D+ampPamp(gt$+ Qamp+-3$+($P IS VCC IB

W+Lamp1(+$+amp(0D( E-50D(+ampX+(gt$+( Qamp+-3$+($P JT BCC H K$+L(ED T CGBH(Y(CGH(

lt405(801amp0$(-(012345( J(L$33gt(gt33A(FCC(05( ampD(0D BS CGIBH(Z(CGBH( IC Qamp+-3$+($P NC IBC H Qamp+-3$+($P BJ VCC IC((IH

=$$gt(302(801amp0$(-(012345( 3$+(L$D(Q3+$D( MampX+(gt$+( amp$+(M$gt$ N IAHCC

amp$+(M$gt$ IF IFACCC 9O-$+amp$ FC IC

0$+3(801amp0$(-(012345( B([0(9O-amp1+()33A( IHCC(05 ampD(0D II I

K$+L(0D amp$+(M$gt$ amp$+(M$gt$

NJ B IB

GBH(Y(IGC( FAHCC IACCC

Qamp+-3$+($P Qamp+-3$+($P

IB N

BCC NACCC

12

13

Table13 3 Water13 quality13 ranges13 at each13 culture facility$amp ($)$++) -+$

-)amp012$)32$45 -6+)01763865 9$01-+3lt5 =amp+)01gt+39+5 $amp()amp+ ++)$6)+01A5

J gtLNL01O5 8P$ampamp401O5 ($Q+

BC3DE DD3DF BG3DB KLM3MLE KLH3MLI KLH3MLF CLM3BFLE CLM3BFLE CLM3BFLE

RQS0Aamp$ RQS0Aamp$ RQS0Aamp$ )ampQTamp$ )ampQTamp$ )ampQTamp$

8+)$O(6+T$ 8+)$ 8+)$ A6$)amp A6$)amp A6$)amp

BH3BI KLH3MLE CLM3BFLE

RQS0Aamp$ )ampQTamp$ 8+)$ A6$)amp

-01 ++)$6)+01A5 J gtLNL01O5 8P$ampamp401O5 ($Q+

BK3DE DD3DM BK3DE KLC3MLC KLC MLC DLM3GLK DLM3GLK DLM3GLK BIC3BMM BIC3BMM BIC3BMM

2ampamp$03040UQ$0amp0)6Q0amp0UampQ0ampamp0VampQ

BE3BI KLC

DLM3GLK BIC3BMM

213amp+(4amp50amp ++)$6)+01A5 J gtLNL01O5 8P$ampamp401O5 ($Q+

DH3DC DH3DC DH3DC KLK3MLE KLK3MLE KLK3MLE KLE3KLC ILC3KLE ILE3ILC BEE BEE BEE

+0$0amp+amplt+066)+0V$ampamp4S0RQ0$0)TP0T

DH3DC KLK3MLE FLC3ILC BEE

6137 ++)$6)+01A5 J gtLNL01O5 8P$ampamp401O5 ($Q+

BB3DC BB3DC BB3DC KLF3MLD KLF3MLD KLF3MLD CLE3BD CLE3KLD CLE3KLD BBG BBG BBG Aamp$ Aamp$ Aamp$

BB3DC KLF3MLD CLE3KLD BBG Aamp$

8$$9(35 ++)$6)+01A5 J gtLNL01O5 8P$ampamp401O5 ($Q+

BK3DE DE3DC BK3DE KLC3MLE KLC3MLE KLC3MLE HLE3GLE HLE3ILE HLE3GLE HEE3FEE HEE3FEE HEE3FEE RQS0Aamp$ RQS0Aamp$ RQS0Aamp$ A6$)amp A6$)amp A6$)amp 8+)$ 8+)$ 8+)$

BH3BM KLC3MLE FLE3GLE HEE3FEE RQS0Aamp$ A6$)amp 8+)$

lt3$+ ++)$6)+01A5 J gtLNL01O5 8P$ampamp401O5 ($Q+

BG3DI DI3DM BM3DM KLK3MLD KLK3MLD KLK3MLD FLE3BDLE FLE3BDLE FLE3BDLE DDI DDI DDI

A6$)amp

BF3BM KLK3MLD FLE3BDLE DDI

Bubbling Ponds State13 fish Hatchery13

Bubbling Ponds Fish Hatchery in Arizona does not maintain razorback sucker

broodstock on site Razorback suckers are received either as juveniles from13 Willow Beach

National Fish Hatchery13 or as13 newly-shy‐hatched larvae from13 Dexter13 National Fish Hatchery

Larval fish are13 typically13 placed13 into13 an unfertilized unlined 0613 acre13 pond13 in the13 spring In

September the pond is harvested by draining the pond and seining All fish that have

reached the target size (300 mm TL) are stocked Fish that are too small to stock are split

up equally between the six remaining grow-shy‐out pond at an13 average13 density13 of about 5000

ndash 7000 fish per pond Fish are fed by hand at approximately 25 body weight split

between morning and evening feedings Fish are either fed a catfish diet made by Rangenreg

13

13

that is enriched with spirulina and krill or razorback sucker diet made by Silvercupreg

depending on availability Fish are monitored visually and by sampling using a cast net

When a large number13 of fish have13 grown to13 the13 target size they13 are13 harvested13 by13 draining

the pond and seining13 Fish are again13 sorted by hand and the largest13 fish are stocked13 Fish

that13 have not13 reached the target13 size are returned to the ponds for further grow-shy‐out13 On13

average it13 takes one to two years for fish to reach the target13 size with fish growing13 an

average of 06 mmday Target numbers for production are 12000 razorback suckers

annually (300 mm TL) The biggest difficulty in rearing razorback suckers at Bubbling

Ponds13 Fish Hatchery13 is protozoan13 parasite13 infestations13 (Ich) and13 associated13 bacterial

infections that come from13 an open spring source that is inhabited by mosquitofish

Dexter National Fish Hatchery13

Dexter National Fish Hatchery maintains four separate razorback sucker13

broodstocks13 These fish are spawned on13 site and larval13 fish are placed directly into 01 acre

ponds at a density13 of about 20000 larvae13 per pond (50 ndash 100 thousand13 per13 acre)13 Ponds

are fertilized with alfalfa13 pellets and superphosphate two weeks prior to receiving13 larvae to

produce13 natural13 feed for larval13 fish13 Ponds are13 fertilized again with alfalfa13 pellets one week

after larvae are introduced13 Fish are fed a catfish starter diet13 (sizes 1-shy‐3) made by Rangenreg

that13 is enhanced with spirulina13 and krill13 and then switched over to the razorback13 diet13 once

they are large enough to eat 1mm13 crumble Fish are fed twice a day by hand four days a

week13 at 25-shy‐60 body weight Feed ration is decreased if excess feed is seen remaining

on the13 pond bottom13 following feedings Fish are not graded or sorted during this grow-shy‐out

period Razorback suckers are harvested in the fall by draining ponds completely Fish are

sorted13 at harvest and13 distributed13 to13 other13 facilities13 for further13 grow-shy‐out depending on13

current size requirements Razorback suckers are on average 100 ndash 200 mm TL after the

first growing13 season13 and13 generally13 take13 1 -shy‐18 months for a majority of the fish to reach

300 mm TL There are 16 different species of fish maintained at Dexter National13 Fish13

Hatchery13 and13 having sufficient pond13 space13 to13 grow out separate13 groups13 of fish is the13

limiting factor for production of razorback suckers at this location

14

13

Grand Valley13 Native13 Fish Facility13

The Grand Valley Native Fish Facility maintains its own brood stock13 in13 eight13 ponds

located at the Horsethief Basin Wildlife Area in Grand Junction Colorado Fish are

spawned13 on site13 and13 larvae13 are13 reared13 indoors in fiberglass13 tanks13 at the13 24-shy‐Road13 Fish13

Hatchery13 in Grand13 Junction The 24-shy‐Road13 Hatchery13 consists of two13 separate13 recirculating13

systems that operate using de-shy‐chlorinated13 city13 water13 and two13 large13 fluidized-shy‐ bed sand

filters13 and13 rotating-shy‐drum13 filters for waste removal Fish are held in 4-shy‐foot (n=78) or 8-shy‐foot

(n=14) diameter fiberglass tanks Larval fish are started on prepared feeds immediately

after swim-shy‐up and fed exclusively razorback feeds made by Silvercupreg Fish are started on

a 0-shy‐250 micron razorback diet for the first 10-shy‐1213 days13 and13 then13 fed with13 gradually13

increasing13 feed sizes based13 on observations of feeding13 (250 ndash 400 micron 1 starter) Feed

sizes are mixed when transitioning to the next larger feed size These razorback diets are

specially sifted by Dr Rick Barrows (USDA13 Hagerman experiment station Idaho)

Razorbacks13 are13 typically eating 1mm13 extruded pellets by the time they are 35 to 4 inches

in length Fish are fed approximately 70 body weight per day initially and then gradually

reduced to 15 body weight by the time they reach the 300 mm TL target size Fish are

fed seven days13 a week using13 12-shy‐hr13 belt feeders It takes13 12-shy‐16 months to grow fish to the

target13 size in13 the hatchery13

Razorback suckers are sorted after three months and culled to about 4000 fish per

family lot Culled fish are stocked into leased grow-shy‐out ponds Stocking densities for

juveniles in these ponds is based on previous13 stocking and harvest13 rates13 and is pond

specific13 Grow-shy‐out ponds are13 harvested13 periodically13 using Fyke13 nets13 or trap13 nets13 and13 fish of

the target size are stocked Disease problems (Ich Lernea) water quality problems (low

DO) and difficulty in removing all of the fish are challenges for grow-shy‐out of razorback

suckers13 in these13 natural ponds13

Fish reared13 in the13 24-shy‐Road facility are sorted again at four to five months of age into

small and large size groups to obtain more uniform13 growth rates Batch estimates of fish

weight are done every month for each tank A group of fish are weighed and counted to

give an average weight for the tank with lengths estimated based on a lengthweight chart13

The biggest difficulties13 for growing13 out razorback suckers13 at the13 24-shy‐Road13 Fish13 Hatchery13 are13

insufficient space and water flow (oxygen) to grow fish to the target size At the Horsethief

15

13

Basin13 Ponds where broodstock13 are reared13 diseases such as Ich are problematic because

water is pumped directly from13 the Colorado River

Ouray13 National Fish Hatchery13

Ouray13 National13 Fish Hatchery maintains its own broodstock and13 spawns13 fish on-shy‐site13

Larvae are transferred from13 indoor hatching tanks to unfertilized 02 acre outdoor ponds

and stocked at densities 10000 ndash 20000 larvae13 per13 pond13 Even13 though13 outdoor13 ponds13 are13

covered with13 bird13 netting13 avian predators13 still get caught in the13 nets13 if they13 can see fish

Ponds are dyed blue13 as the13 fish grow to13 prevent avian predation13 While in the outdoor

ponds13 fish13 are13 fed a slow-shy‐sinking salmon diet made by Silvercupreg twice daily by hand

Amount of feed is based on periodic sample counts Fish are grown until late September at

which time temperatures require that all fish13 other13 than13 adult broodstock13 be13 brought

inside for the winter Ponds are drained completely and fish are sorted by hand Fish that

have reached the target size (300 mm TL) are stocked into the Green and Colorado Rivers

All remaining fish are moved indoors13 and13 held13 in three-shy‐foot (n= 30) or eight-shy‐foot (n=27)

diameter circular tanks On average it takes 12 ndash 18 months to grow fish to the 300 mm TL

at Ouray13 hatchery13

Razorback suckers are held during the winter in a recirculating system13 that

operates13 using13 two13 large13 fluidized-shy‐bed sand filters and a rotating-shy‐drum13 filter for solids

removal Fish are fed the Silvercupreg razorback diet using belt feeders There is currently

capacity13 to13 hold13 only13 20000 200-shy‐300 mm TL fish inside the facility and any extra fish13 are13

stocked13 into13 floodplain-shy‐wetlands or used for research purposes13 Ouray no longer leases

any private grow-shy‐out ponds Grow-shy‐out ponds were troublesome due to poor water quality

harvesting13 difficulties13 and13 non-shy‐native13 fish introductions13 The biggest difficulty13 for

production13 of razorback13 suckers at the Ouray13 National13 Fish13 Hatchery13 is space13 during13 the

winter to maintain large numbers of fish and high iron and manganese in the well water

that must be filtered out prior to use

16

13

Willow Beach National Fish Hatchery13

Willow13 Beach National13 Fish Hatchery receives wild-shy‐caught larvae from13 Lake

Mohave Larvae are treated for diseases with formalin and malachite green and placed in

45 ten-shy‐gallon13 flow-shy‐through aquaria13 Recirculated13 solar heated water13 22-shy‐25deg C is used to13

allow production of warm13 water fish at this traditionally cold water facility (Figiel 2003

Figiel et al 2005) Fish are fed brine shrimp nauplii to satiation every hour and after 14

days small amounts of specialized larval fish diet (Encapsulon13 Cyclopeeze13 spirulina13 and

artificial plankton) are introduced After 30-shy‐6013 days13 fish are13 transferred13 to13 six13 32-shy‐gallon13

fiberglass troughs at densities of 1000 to 1500 fish per tank and then a month later moved

outside13 to13 eight recirculating13 raceways that use a combination of well water and solar-shy‐

heated water to maintain temperatures of 22 ndash 25deg C during the summer months

When13 in13 the outside raceways13 fish are fed the razorback13 diet13 using13 belt13 feeders and

fed by13 hand13 at 10 -shy‐ 70 body13 weight per13 day Feed amount is adjusted based on sample

counts according to a feed conversion program13 developed for razorback suckers by Willow

Beach Hatchery personnel This program13 uses length and number-shy‐per-shy‐pound generated

from13 several years of razorback growth data (Figure13 1) Fish are13 sorted13 opportunistically13

and are not handled during the summer months when water temperatures are above 20degC

In 2004 the target size for stocking was 325 mm TL or greater (WBNFH 2004) with a

target13 of producing13 6000 fish per year Reaching this13 target size usually13 takes13 two13 growing13

seasons13 The biggest difficulty13 in rearing13 razorback suckers13 at Willow Beach13 National Fish

Hatchery13 is insufficient space13 to13 grow fish to13 increased13 target sizes (400-shy‐500 mm TL)

Uvalde13 National Fish Hatchery13

Uvalde13 National Fish Hatchery13 in Texas13 receives 35000 ndash 60000 razorback sucker13

fry annually in MarchApril from13 Dexter National Fish Hatchery The fry are acclimated in

bags submerged in the pond for a minimum13 of one hour and released into13 a 1 acre13 fertilized13

pond where they are reared for the remainder of the summer Fingerlings are fed a starter

razorback diet when they reach approximately 50 mm TL In AprilMay the previous year

class of razorbacks are captured from13 their over-shy‐wintering pond enumerated graded and

split into13 one-shy‐acre grow-shy‐out ponds Approximately 4000 ndash 5000 fish will be13 placed13 in each13

one acre pond for summer grow-shy‐out Fish are reared for approximately 150 days (May ndash

17

13

Oct) and fed the Bozeman razorback diet two times a day five days a week at 15 ndash 30

body weight per day based on average water temperature

Figure 1 Relationship between length and number of fish per pound

In general13 juvenile razorback13 suckers (received as fry13 during13 the previous spring)13

reach the target size of 300 mm TL in approximately 6 months In 20062007 Uvalde

produced 6000 razorback suckers 300 mm TL for introduction into the San Juan River

Starting13 in 2008 Uvalde NFH will be producing13 and distributing13 12000-shy‐ 300 mm TL

razorbacks for stocking into the San Juan River Predation from13 migrating cormorants has

occurred but timing of harvest and over wintering protection methods such as covering

ponds with netting or placing fish indoors helps to minimize losses during the cormorant

migration (November to March) Uvalde has experienced razorback mortalities because of

bacterial problems but these are usually resolved through the use of oxytetracyline

medicated feed

Overview13 of Differences in Culture Methods

Several differences were noted when conducting surveys at each of the five main

production facilities for razorback sucker (See Appendix 3) These differences include

different stocking13 and13 rearing13 densities13 (Table13 4-shy‐5) various feeding regimes and type of

18

13

lt=amp

feeds (Table 7) as well as differences in grading or sorting practices Some of these

differences are13 related13 to13 whether13 or not razorback suckers13 are13 being13 reared13 in extensive-shy‐

culture13 facilities13 (ponds) or intensive-shy‐culture13 settings13 (raceways13 o tanks)13 Some13 practices13

are unique to a single facility13 or a couple of facilities (Table 6)13 Managers at each facility13

were asked to identify the biggest13 difficulty or constraint13 that13 they experience when13

growing-shy‐out juvenile13 razorback suckers13 at their13 respective13 location13 Space constraints13

water quality and disease problems were the main factors limiting production of razorback

suckers13 at these13 facilities13 (Table13 8) Calculated or reported growth rates from13 the literature

vary widely (Table 9) and range from13 02 to 18 mmday These growth rates indicate that

juvenile razorback suckers have a very high growth potential under optimal rearing

conditions13

Table13 4 Stocking13 densities13 for larvae13 and13 fry in ponds

$amp( )(+amp-( 01-2(3(4amp56( 4amp56(+amp-( 01-2782-( $amp () + --amp +amp0amp)+amp 12-3amp ( )+amp0amp+amp --amp +amp0amp)+amp 42556789amp8 ( +amp0ampgt+amp 3amp +amp0amp+amp A-BC-Damp (E + 3amp )+ F-6ltamp ) G+ 3amp G+

Table13 5 Rearing13 densities13 at intensive13 culture13 facilities13

$amp( )amp+(($-( $0( 12(3$+( 40((amp05( 67((amp05( 8$9(407$( $amp amp())amp++-$amp 0 1 0amp2amp1amp 3amp2amp4 0544

6amp())amp++-$amp 610 021 4amp2amp47amp 3amp2amp77amp 058 9$amplt+)amp 4amp())amp++-$amp 00 1 7amp2amp77amp 851amp2amp0amp 05

6amp())amp++-$amp 610 77amp2amp1amp 0amp2amp1amp 053

19

13

Table13 6 Rearing13 practices13 that are13 unique to13 specific rearing13 facilities13 $$amp( )$+-(amp$-(0(1-amp2034( $amp()amp+( -0$(12(33+(amp(amp134$53+(amp$amp3+(6amp+(

723(843(1$8(422(6amp+(42amp(4(423(19$43( 343( lt34$53(6amp+(6(4($03(amp4+94amp(842($1$1(63$$34(amp+(63626243( =amp+(gtamp94ampA( B3(1(1$+53+C3+(amp+(1$43(1(3D0$(1(amp443(amp+(amp443( 734231(amp( B3(1(193(44(1(34amp(amp(+49E(6amp+( -E3(F3+( G3amp(1(12(amp(H3(13$(4ampE(C(IJK($$amp( A( L43(+A3(4(6303amp4(63+4ampM(66$3D3amp4$(34amp(amp(6amp+(C((4amp3( L$$8(392(

B0$+3(

N43D(13+(4($0$(12M(amp+(639$53+($0$(12(+34( G3amp(12(amp(399$4amp(4+(938A(842($(2343+(843( N443D643+(3amp(12(amp(amp34(63amp(amp(423(O$+(G03( )amp+(3(134$53+(6(4(39364(1(1A(4(44(423D(amp((D3(amp4$(+34(

Table13 7 Types of feed used at razorback sucker13 hatcheries13 $amp ()amp+-amp0- $$)1amp23 45-amp)-$5)1amp23 $amp()amp+( -amp$amp+(amp+( -amp012$3+(amp+4(amp5215$(0+( 65ampamp7(85209(+2($1(87((15315lt=(+2(

+amp+amp(amp(55$5$2gt( 21( Aamp+(amp+( )amp+(012$3+(B29(5$05$95($$2(5amp+(

199524(amp5215$(0+( 65ampamp7(85209(+2($1(87(15315lt=(+2(amplt( 29gt(51($51(amp9(2(25=(C(DD(0+(

E15amp+(Famplt2amp( G1$5(lt1lt$51(25amp=( HIJKH(Dlt1amp(15315lt=(+2(I(C2(CH(+5gt( )11$gt($511(02+(15315lt=(+2(

$1(87(15315lt=(+2(D5$$(3(lt5$$gt(02+(gt( 6lt=(511B(

L15gt( G1$5(lt1lt$51(25amp=(Aamp+( amp+(

HIJKH(Dlt1amp(15315lt=(+2(I(C2(CH(+5gt( )11$gt($511(02+(15315lt=(+2(

$1(87(15315lt=(+2($1(87($B(amp=amp( 5$Damp(+2(

M$$B(5lt9(-5$+( NO515(G1$5(219( L2+1(15ltB5gt(Aamp+(5amp+( amp$amp+(amp+(

1amp(91D(amp5$(Pamplt5$amp4( 8gtlt$34(1$amp54(5amp+(5120lt5$( $5amp=2amp()amp+(012$3+(B29(5$05$95( $$2(5amp+(19952Q(amp12152( 1+lt2amp(

$1(87(15315lt=(+2($1(87(15315lt=(+2( $1(87(15315lt=(+2(

Table 8 Factors limiting production at major razorback sucker facilities

$amp( )amp+(-0+1((2$(0amp1ampamp(-34amp( $amp()amp+( -(01$2(34+(546(amp(0amp(01amp(541(13( -741( 803(3amp41amp4(9((+ltlt1amp4(03(amp(44amp(2=(4(

+ltlt3$4(4(2amp4amp(014(1gt13=(43=( 1amp+(amp34amp( 803(3amp41amp4(1$4+(4(541(A$4B(amp+(+$C+(

7Bamp($244amp(lt(1313$4amp(B42( D1B( E41(A$4B(01$2(3+(B(66(1amp(amp+(2ampamp(

Eamp41(420141(464(1A1($$(lt6(4((2C+(amp+1( 803(3amp41amp4(1$4+(4(541(A$4B(amp+(+$C+(7Bamp(

E$$5(36( 803(3amp41amp4F(15amp(lt6(4(amp31amp$B($11(gt( 1$4(amp(ampltlt3amp4(03(amp(44amp(lt1(amp5(lt6(

GC$+( 8221(420(3amp(4(6691A1amp(051((4(410$(+(4( 661(1amp+541(020amp(4(=0(0amp+(3$F(

20

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Table9Reportedandcalculatedgrowthratesfromtheliterature

Calculatedgrow

thratesbasedon

informationprovidedinliterature

aApproximationsofmaximum

grow

thpotential(basedon

average13 maximum

sizesiffishreportedatharvest

21

13

General Information on Factors that Affect Fish Growth

Growth in fish is extremely variable and is impacted by many different

physiological and environmental factors Growth rates are known to change with size and

age sex season activity level density amount13 of living space quality and quantity of food

genetics and temperature (Brett 1979) Growth experiments conducted at different times

of year can result in growth rates that are not comparable As fish become larger their

physiological13 potential to grow decreases making determination of growth rate dependent

on the size of the starting fish and the length of the experiment (Busacker et al 1990)

Genetic factors also have great potential to influence growth rate Some species have

strains13 and13 races13 that display vastly different growth potentials (Reinitz et al 1979) All of

these factors combine to make assessment of the individual factors controlling fish growth

difficult13

Water temperature is probably the most important variable affecting growth rate13

All of the basic functions that affect growth such as feeding digestion and metabolism are

temperature-shy‐dependent13 Growth13 is inseparably13 tied13 to13 bioenergetics13 and13 therefore13 also13

tightly tied to temperature When temperatures are below optimum daily temperature

fluctuations can stimulate growth Photoperiod is also commonly linked to water

temperature and can influence growth rates in fish (reviewed in Brett 1979)

Fish density13 is known to13 affect growth13 and13 can alter13 growth13 rates13 in several ways13

Fish that exhibit strong territorial behaviors13 or natural schooling tendencies13 will

experience reduced growth if densities are too high or too low (Brett 1979) Dominance

hierarchies where some fish feed more aggressively than others can also lead to high

variability13 in growth13 rates13 (Koebele13 1985) Crowded13 conditions13 also13 cause physical

interference13 between13 fish and13 poor water13 quality13 which13 reduces13 growth13 (Busacker13 et al13

1990) The effects of fish numbers space and feeding opportunity are frequently correlated13

and often13 difficult13 to distinguish (Brett13 1979)13

It is impossible to study the effects of environmental factors on growth without also

evaluating feed rations (Brett 1979) Amount of food quality of the diet particle size

number of feedings per day and time of feeding have all been shown to affect growth

(Busacker et al 1990) In controlled laboratory studies food is usually fed ad libitum13

22

13

(constantly available) and other variables are altered to assess impacts of environmental

factors13 on growth13 These studies13 are13 usually13 conducted13 in tanks13 or raceways13 because13

researchers must verify that food is constantly available to the fish which is difficult to do

in large pond environments where the fish and the bottom13 are often not visible (Busacker13

et al13 1990)

Specific Information13 o Razorback13 Sucker13 Growth

Variable13 growth

Growth in razorback suckers is naturally highly variable and may be a function of

their evolutionary history (USFWS13 2002)13 Minckley (1983) speculated that13 wide size

variation in a single cohort of razorback suckers may be adaptive with fast-shy‐growing13 fish

that13 reproduce at a young13 age surviving13 better in13 high discharge years and slow-shy‐growing13

smaller fish surviving better during drought periods This highly variable growth rate

makes rearing razorback suckers in a production setting difficult because fish from13 a single

cohort do not reach the target stocking size simultaneously One of the major tasks for

aquaculture is to maximize both individual growth and total production13 (Gerking13 1978)13

This becomes more difficult when the species being cultured exhibits highly variable

growth13 rates13 because of genetic influences as is the case with razorback13 suckers13

Razorback13 sucker growth13 is typically very13 rapid13 during13 the first13 year of life13 and then13

declines with age First year growth can be as low as 50 mm and as high as 350 mm (Valdez

et al13 1982 Minckley13 1983 Mueller13 1995) Razorback sucker13 grow rapidly13 for

approximately the first five or six years of life and then growth slows13 (McCarthy13 and13

Minckely 198713 Tyus 199813 Minckley et13 al 1991)13 Growth of older individuals in13 extant13 wild

populations is very13 low (Minckley 198313 Tyus 198813 Modde13 et al 1996)13 Wild growth13 rates

for mature adult fish in Lake Mohave based on PIT tag recaptures were often too small to

be accurately measured for both males and females over the time period of 1987-shy‐199713

(Marsh and Pacey 1998) This information suggest it will take substantially longer to rear

fish to13 increasingly13 larger13 stocking13 sizes (40013 ndash 500 mm TL) than it did to reach the target

size of 300 mm TL

Growth in ponds

23

13

One of the main strategies for maintaining genetic refugia and self-shy‐sustaining13

populations of razorback13 sucker in the lower Colorado13 River basin13 is to rear razorback13

sucker13 larvae13 in production13 ponds until they13 are13 a suitable13 size for stocking13 (USFWS13 2004)

Pond culture has proven useful to promote rapid growth of juvenile razorback suckers

(Kaeding and Osmundson 1989) Marsh (1994) reported that growth rates of razorback

suckers13 reared13 in golf-shy‐course13 ponds exceeded13 the13 best growth13 rates13 obtained13 under

intensive13 culture13 conditions13 at federal hatcheries13 especially13 during the13 first several years13

of life Growth rates in these semi-shy‐natural ponds are also comparable to estimated growth

rates13 of juvenile13 wild13 fish (McCarthy13 and13 Minckley13 1987) Modde13 and13 Haines13 (2005)

reported13 the13 greatest growth13 rates13 in the13 largest and13 deepest floodplains13 with13 the13 greatest

amount of submergent vegetation but excellent growth and survival of fish in a grow-shy‐out

pond is of little value if there is not an efficient way to collect the fish from13 the pond

(Kaeding and Osmundson 1989)

Temperature13

Bulkley and Pimentel (1983) used shuttle boxes in the laboratory to determine a

temperature preference13 for razorback suckers13 of 23-shy‐24degC13 In13 their13 studies13 razorback

suckers were found to avoid temperatures below 118 degC or above 286 degC Razorback

suckers at Bubbling Ponds Hatchery are more active in the spring and feed better as

photoperiod increases even prior to water temperatures rising (Frank Agygos personal

communication) Table 3 briefly summarizes water temperature data from13 each facility

Detailed seasonal water temperature profiles are not currently available for many

razorback grow-shy‐out sites13

Density13

Extensive studies have been conducted on commercially important species to

evaluate stocking densities and feeding rates that maximize production For these species

controlled experiments under laboratory conditions have established relationships

between temperature density and feed ration on growth (Brett 1979) but this information

is sporadic13 or non-shy‐existent for razorback suckers13 (Bays13 et al13 2005) Fish culturists13 with13

24

13

experience13 rearing13 razorback suckers13 typically13 have13 target stocking13 densities13 that13 they use

(Tables13 4 -shy‐ 5) These stocking densities have largely been determined over time by trial

and error These approximate stocking densities provide a good starting point for more

controlled13 types13 of replicated13 pond studies13

Feed ration

Razorback13 suckers are currently13 being13 fed a wide variety13 of prepared diets (Table 7)

that range from13 a slow-shy‐sinking salmon feed manufactured by Silver Cupreg to a spirulina

and krill-shy‐enhanced catfish feed made by Rangenreg Most locations are feeding 20 ndash 50

body13 weight per13 day13 Methods13 for culture13 of razorback sucker13 larvae13 in intensive13 settings13 at

fish hatcheries are well documented (Figiel 2005) and various larval fish diets have been

evaluated13 (Tyus and13 Severson 1990 Severson et al13 1992) but no standardized13 procedures

are used for feeding13 larval13 fish in13 intensive settings13

Razorback sucker larvae are also effectively reared in pond environments using

natural foods supplemented with larval fish diets and survival is high when no predators

are present13 (Mueller 2006)13 Growth rates for larval13 and early juvenile razorback13 suckers

may increase with pond fertilization Diet and physiological studies on wild razorback

suckers indicate that they feed on plankton as well as benthic organisms during their entire

life (Marsh 1987) Artificially fertilizing ponds may greatly increase production capacity

and growth rates for razorback13 sucker (Papoulias and Minckley13 1992) and warrants

further13 investigation13

Handling stress

Handling stress13 has13 been shown to13 influence growth13 rates13 Paukert13 et al (2005)

found that growth of bonytail chub was reduced by 26when compared with controls

after being13 repeatedly13 captured and handled in13 hoop13 nets13 Handling13 effects are likely13 to be

similar for razorback suckers that are repeatedly13 captured and sorted in13 a hatchery13 setting13

Razorback suckers that are handled at Willow Beach National Fish Hatchery will commonly

not eat for two weeks after handling (John Scott personal communication) This creates a

difficult situation13 for production13 facilities because13 fish13 need to be sorted to ensure13 large13

25

13

aggressive fish do not interfere with growth of smaller individuals but frequent handling

and sorting13 causes stress related reductions in13 growth13

Measuring Growth in Captive Fish

Weight is the traditional measure used to estimate growth or production in

aquaculture settings13 Groups of fish are typically13 weighed and an average individual13 weight13

is computed (Busacker et al 1990) Although this method is often logistically the easiest it

may not be the most informative for species with highly variable growth rates like

razorback suckers especially when target lengths must be reached before fish can be

stocked Weight can also be highly influenced by things like stomach fullness or

development of gonads (Busacker et al 1990) Condition factor or relative weight can also

be used to assess growth of fish but these tools may be more robust predictors of fecundity

than of growth (Anderson and Neuman 1996) For some species sexes need to be

distinguished because males and females may differ in morphology (Anderson and

Neumann 1996) Mueller (2006) analyzed growth rates based on PIT tag recaptures of 86

razorback suckers13 in High13 Levee Pond13 and13 found13 that differences13 in growth13 do not appear13

to occur until fish are over 450 mm TL at which time growth rate in males slows while

females continue to grow at a slightly higher rate This would indicate that sex may not be

an important factor to consider when examining growth rates unless the target grow-shy‐out

size is above 450 mm TL

The best measures of growth are often determined from13 the length and weight of

individuals rather than from13 groups of fish (Anderson and Nuemannn 1996) because

individual growth rates give better estimates of confidence and variance (Busacker et13 al

1990) Length frequency analysis or recapture of previously marked individuals of a known

size is likely to yield the most useful information for razorback sucker growth The success

of any of these methods depends on proper sampling procedures that are representative of

the population as a whole (Busacker et al 1990) Sampling methods that are known to be

size-shy‐biased such as trammel nets (Mueller et al 2004) or cast nets should not be used when

trying to measure growth rates13

26

13

Conclusions

For razorback sucker survival is largely associated with stocking size Additional

focused13 research13 is therefore13 needed to13 identify13 ways13 to13 increase13 growth13 rates13 of captive-shy‐

reared13 razorback sucker Growth13 rate13 in fish is controlled13 by many factors including fish

size and age temperature density and feed ration which can all be highly correlated

Growth of razorback suckers is also inherently variable which makes the task of identifying

the key factors that13 affect13 growth in13 captivity even more difficult The focus at most

razorback rearing facilities13 is production so the13 types13 of data that are13 collected13 are13 often

insufficient for detailed13 evaluations13 of individual rearing13 practices13 on growth13 Surveys of

existing13 razorback sucker13 rearing facilities indicate that culture methods vary widely and

the types of growth data13 that13 are collected are not13 standardized13 Replicated studies with

detailed information on rearing location water temperature initial stocking size stocking

density and the sizes of all fish at harvest are needed in order to compare the effects of

individual rearing practices on growth This type of research will ultimately provide both

time and cost-shy‐savings to production facilities by reducing the amount of time necessary13 for

razorback sucker to reach stocking size improving overall production efficiency

Optimum13 rearing densities for razorback sucker larvae and juveniles remain to be

determined Current stocking densities will be very useful as starting point for more

detailed studies and although optimum13 rearing densities are likely to be site-shy‐specific13

replicated studies on density will provide a valuable reference for hatchery managers

Frequency13 of sorting is another13 area that needs13 further13 research Frequent

handling13 and13 sorting13 can13 cause13 stress-shy‐related13 reductions13 in growth but not sorting can

create dominance hierarchies that further reduce growth rates of subordinate individuals

The effects13 of sorting13 on overall fish growth13 in both13 pond and13 intensive13 culture13

environments warrant further investigation Research techniques for these types of

experiments are well understood and typically utilize a matrix of replicate ponds per

variable (Bays et al 2005) In every case accurate and complete records of sampling

procedures and data collection are needed in order to interpret data and make inferences

about13 growth rates (Busacker et13 al 1990)13

27

13

Additional research is also needed to evaluate long-shy‐term13 survival of stocked fish

reared in ponds compared to fish13 reared13 in intensive13 culture13 facilities13 Exercise13

conditioning13 and predator-shy‐recognition training may also increase survival of stocked fish

and be more economically feasible than rearing fish to increasingly larger sizes prior to

stocking13 The success13 of traditional fish hatchery programs is measured largely by the

number of fish stocked but hatchery programs for endangered species must measure

success in terms of long-shy‐term13 survival and species recovery (Brannon 1993 Anders 1998)

A specific list of research recommendations follows

Specific Research13 Recommendations13

bull Use replicated studies13 to establish optimum stocking13 densities13 for ponds13 and

tanks13 that can be used as13 a starting13 point for site specific refinement

bull Determine if sortinggrading13 improves13 overall growth rates13 in both ponds13 and

intensive culture facilities13

bull Investigate the use of artificial fertilizers13 to improve growth of both juvenile

and adult razorback suckers13 in ponds13

bull Determine if the razorback sucker diet gives13 better growth rates13 than cheaper

catfish or salmon feeds

bull Evaluate growth rates13 and production potential of new intensive culture

methods13 such as13 large circular tanks13

bull Evaluate13 long-shy‐term survival of fish produced from raceways13 and circular tanks13

compared to fish reared in ponds13

bull Evaluate more effective means13 of treating13 fish diseases13

bull Evaluate factors13 other than size that may increase post-shy‐stocking13 survival such

as13 exercise conditioning13 predator recognition training or rearing13 under more

natural settings13

28

13

II The Effect of Disease Treatments on Razorback Sucker

Growth

Section13 SummaryFormalin copper sulfate potassium permanganate and13 salt are all chemicals commonly13 used13 to13 treat13 Ichthyophthirius multifiliis outbreaks in captive razorback sucker (Xyrauchen13 texanus) Weexposed 190 juvenile13 razorback suckers (127 ndash 26 mm TL) to13 5 5-shy‐day treatments with13 each13 chemical to evaluate the effects13 these chemicals13 may have on growth Fish grew an average of23513 mm TL13 during the month13 study period Fish treated with formalin grew on average13 29mm TL (03 mmday) while fish treated with copper had the lowest growth averaging 20 mmTL (021 mmday) No significant differences in13 growth were observed among fish treatedwith any of the chemicals compared to untreated fish (pgt005) Reductions in growth13 as aresult of repeated chemical treatments are not likely the cause of differences in growth ratesamong13 facilities that raise razorback suckers Repeated chemical treatments may13 have otherimpacts to overall13 fitness or long-shy‐term survival but13 these effects were not13 evident13 in our study

29

13

Introduction

Preservation13 of razorback sucker13 (Xyrauchen texanus) currently13 depends on captive13

rearing and stocking programs until permanent solutions to factors that prevent wild13

recruitment are found Low survival of stocked razorback suckers (Brooks 1986 Marsh

and Brooks 198913 Marsh and Pacey13 2005) has caused target13 sizes for stocked fish to

steadily increase in efforts to reduce predation mortality (Marsh et al 2005 Schooley and

Marsh 2007) Rearing fish to larger sizes at hatcheries comes with increased costs and

creates the need to evaluate husbandry and rearing practices that may affect fish growth

Formalin copper sulfate potassium13 permanganate and salt are all chemicals

commonly used at razorback sucker rearing facilities to treat outbreaks of the protozoan

parasite13 Ichthyophthirius multifiliis ldquoIchrdquo is one of the most pathenogenic diseases of

cultured13 freshwater13 fishes (Matthews13 2005) and causes large13 losses in captive13 populations13

of endangered razorback sucker Each of these chemicals used to treat Ich only kill the free-shy‐

swimming life stage of the parasite13 requiring13 repeated doses over several13 days depending13

on water temperature These chemicals treatments are needed to prevent loss as a result

of disease outbreaks but the cumulative effects repeated disease treatments have on

growth13 are13 unknown

Copper13 sulfate13 has13 been shown to13 significantly13 reduce13 growth13 of channel catfish13 in

production13 ponds (Rabago-shy‐Castro13 2006) but it is unknown whether13 razorback suckers13

experience similar reduced growth following copper treatment Quantifying the impacts of

disease treatments on growth will help to interpret the wide differences in growth rates

observed13 at various13 razorback sucker13 production13 facilities13 throughout the13 southwest

(Ward et al 2007) If one chemical is found to have less detrimental impacts on growth

than another then it may be preferred for use as a disease treatment We evaluated growth

rates13 of razorback suckers13 under13 replicated13 and13 controlled13 conditions13 to13 assess13 effects13 of

repeated formalin copper sulfate and potassium permanganate and salt treatments on

growth13

Methods

We captured 190 juvenile razorback suckers from13 ponds at Bubbling Ponds Fish

Hatchery AZ using hoop nets or cast nets All fish were of the same age class and

30

13

averaged 179 mm total length (TL) (range13 = 127 ndash 262 mm TL)13 These fish were13 offspring13

of captive13 razorback sucker13 broodstock held13 at Dexter13 National13 Fish Hatchery13 NM13 (2007

year class) All fish were tagged with passive integrated transponder (PIT) tags and

quarantined for one month prior to the experiment to allow fish to recover from13 tagging

and become accustomed to being held in circular tanks

At the beginning of the study all fish were weighed measured and scanned for

individual tag numbers with 19 randomly selected fish placed into each13 of 10 8-shy‐foot

diameter circular tanks (Figure 2)13 Each13 tank contained13 two13 airstones13 and13 an13 individual

biofilter with a recirculating water pump (31 litersminute) that had been operating for

at least 1 month prior to the experiment to allow bacterial colonies to become

established Two tanks were designated as a control and did not receive any chemical

treatments while the other eight tanks received formalin copper sulfate potassium13

permanganate or salt treatments at two week intervals (two tanks per chemical

treatment) Formalin copper sulfate and potassium13 permanganate were treated at 1 part

per million (ppm) and salt was applied at 30 parts per thousand (ppt) These treatment

rates are commonly used to treat13 razorback13 suckers for ich at Bubbling13 Ponds Fish13

hatchery (Frank Agygos personal communication)

Figure 213 Photo ofexperimental tankswith individualbiofilters and aeration

31

13

Each treatment consisted of a series of doses applied on Wednesday Thursday and

Friday with a 90water change between each dose Biofilters were removed from13 all

tanks and held in a separate holding facility during treatments and then replaced on the

Monday following treatments after a 90water change This schedule allowed fish to be

exposed to chemical treatments for 5 consecutive days without water quality deteriorating

This 5-shy‐day chemical treatment was repeated every two weeks from13 July to October (97

days)13 for a total of 5 5-shy‐day treatments Water temperature in the treatment tanks ranged

from13 13degC (55degF) to 32degC (91degF)

Fish were fed a fixed ration of commercial razorback diet (Silvercup 4mm13 pellet)

once daily13 (2 percent body13 weight per day13 as calculated13 by13 average initial fish weight)13

At the end of the experiment all fish were again weighed measured and scanned for

individual tag numbers Growth of fish in each treatment group was compared using

analysis of variance (ANOVA) Any mortalities13 that occurred during the13 study13 were13

replaced with previously quarantined fish of equivalent size to maintain equal densities in

each13 tank13 but growth13 data was13 only13 recorded for fish which13 survived13 the13 entire13

experiment

Results

Fish at the13 start of the experiment averaged 179 mm TL (Range13 = 127 ndash 262 mm)

with no significant differences in fish length among treatment groups (F(4189) = 00183 p

gt 0999 ANOVA) On average fish grew 235 mm TL (024 mmday) during the 3 month

study13 Fish in tanks13 treated with formalin had the highest growth averaging 29 mm TL (03

mmday) while fish in tanks treated with copper had the lowest growth averaging 20 mm

TL (021 mmday) Fish in the control tanks averaged 213 mm TL in growth (022

mmday) (Figure13 3)13 Formalin-shy‐treated fish grew13 significantly faster than13 any other

treatment group but no13 significant differences in growth13 in length13 or weight were13

observed among fish treated with any of the chemicals compared to untreated (control)

fish (pgt005 ANOVA)

32

13

Figure 313 Average growthof razorback suckersexposed to a series of 5 5-shy‐day chemical treatmentsover a 97-shy‐day13 periodError bars representstandard error

Discussion13

Growth13 rates13 observed13 in our study13 (021 ndash 03 mmday) are low compared to those

reported13 in other13 studies13 of razorback sucker13 growth13 (0213 ndash 18 mmday) (Ward et al

2007) Using recirculating water systems for our study required filters to be removed and

replaced during treatments Stress to fish caused by removing and replacing filters within

the tanks as well as repeated water changes may have led to overall higher stress and

reduced growth rates compared to those reported for unconfined fish Growth in fish is

highly variable and is affected by many different physiological and environmental factors

including fish size density temperature amount of space and food (Brett 1979) We

strived to control each of these factors but other factors may have also influenced growth

in our experimental tanks During mid-shy‐summer water temperatures in the treatment

tanks reached 32degC (91degF) At these warm13 temperatures fish are very susceptible to

bacterial13 infections13 The slightly higher growth exhibited by fish in the formalin and

potassium13 permanganate treatments may have been the result of these two chemicals

33

13

being effective at controlling bacterial infections The differences in growth we measured

among treatment groups were not statistically significant and do not appear13 biologically13

meaningful during the relatively short duration of this study (97 days) although the

cumulative effects of slightly reduced growth could be biologically meaningful over longer

time frames

Reductions in growth13 as a result13 o repeated chemical treatments are not likely the

cause of differences in growth rates among facilities that raise razorback suckers

Repeated chemical treatments may have other impacts to overall fitness or long-shy‐term13

survival but these13 effects13 were13 not evident in our study It is more likely that the parasite

outbreaks themselves are the cause of different growth rates among razorback rearing

facilities rather than the chemical treatments used to treat the parasites We recommend

that hatchery managers continue to use the chemicals that are most effective at controlling

ldquoIchrdquo13 at their individual13 facilities

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower Colorado Rive Multi-shy‐species13

Conservation Plan under Work Task C10 We thank Ty Wolters and Tom13 Burke for their

support of this research and Frank Agygos and Dave Billingsly of the Bubbling Ponds Fish

Hatchery13 for their13 technical assistance13 and13 help with13 collecting13 fish

34

13

III13 Razorback Growth Rates at Bubbling Ponds ndash 2009-shy‐2011

Section13 SummaryExperimental studies at Bubbling Ponds Fish Hatchery AZ have strived to understand

factors that affect razorback sucker growth in captivity and identify ways to improve growthrates and maximize size at release Rather than performing experimental studies that wouldrequire major13 rearrangement (and likely reduced production)13 of hatchery operations our13 studies13 used normal variation in production techniques13 and practices13 to isolate factors13 thatmay modify growth rates

Our initial work identified razorback13 growth rates in13 lined ponds at standard fishdensity as 026 to13 028mmday (789 to 843 mmmonth) No significant differences in growthrate were observed among fish that had been in the pond only during the winter13 periodcompared to fish that had been in the pond the entire year indicating that water temperatures13 at Bubbling Ponds are high enough to allow fish to incorporate feed effectively year-shy‐roundHowever these growth rates are lower than most values reported from the literature fromnatural or semi-shy‐natural pond environments No significant differences in13 growth rate wereobserved13 between large and13 small fish13 within the 150 ndash 29 mm TL13 size range Additional worksuggests13 that razorback suckers13 tagged at over 300 mm TL had reduced growth rates (024mmday 73 mmmonth) as would be expected according to a typical Von13 Bertalanfy growthcurve although growth rates13 were only slightly less13 than the average growth rate for thehatchery (027513 mmday 82513 mmmonth)

Sorting13 to13 separate small fish from large fish after the first year of growth is practicedesigned13 to allow smaller fish to ldquocatch uprdquo to larger fish We found that13 this technique doesappear to13 improve growth rates of smaller fish Growth rates of sorted small razorback suckers(029 mmday 87mmmonth)13 were equal to that13 of larger13 fish (028 mmday 8413 mmmonth)indicating that sorting may have helped to offset their original slower growth trajectory

Bubbling Ponds Fish Hatchery grows razorbacks in 6 long deep ponds lined with heavyplastic 2 long deep13 earthen13 (unlined) ponds and three wide shallow earthen ponds The wideshallow ponds13 have historically produced very large fish at low density but have been found tomaintain much lower fish numbers than deeper ponds We found13 that growth13 rates ofrazorbacks kept at high density (4-shy‐700013 fish)13 in a wide shallow pond grew extremely slowly(024 mmday 726 mmmonth) This growth rate is among the slowest of any fish over theyears of our study and demonstrates that13 though the large ponds may produce large fish at lowdensity13 they are unable to overcome high13 fish13 densities

Finally one of the major factors influencing13 fish13 growth13 in hatcheries is disease onemajor summer-shy‐time disease at13 Bubbling Ponds is the ectoparasite Ich (Ichthiopthirusmultifiliis) To investigate the impact Ich has on razorback growth we eradicated fish from thespring and water conveyance ditch that supplies13 water to the hatchery using Rotenone This13 restoration effort was fairly short-shy‐lived (Ich returned to the hatchery within four months) but

35

13

growth13 rates of fish13 reared for four months without Ich present (031 mmday 92 mmmonth)were significantly higher than the following 8 months of growth for those same fish (022mmday 65 mmmonth) This disease-shy‐free growth rate is in fact faster than any13 otherprevious growth rates observed at the hatchery in our study

We conclude that growth rates at the Bubbling Ponds Fish Hatchery are likely as highas possible given the pond densities required to13 meet production goals and the Ich-shy‐infestedwater13 that feeds the facility Sorting practices are successful in helping as many fish as possiblereach stocking length as fast as possible Unlined ponds may be able to grow large fish at lowdensities but whatever factors allow for that growth13 are not able13 to overcome13 high fish densityThus the large lower ponds at Bubbling Ponds may be better utilized via renovation to13 deepenand line them

Disease is the most important factor limiting growth as may be expected to be the caseat many13 hatcheries While the spring renovation was not13 a complete success13 the dramaticreduction of fish populations in that habitat was enough to dramatically13 reduce13 the13 occurrenceof Ich at the hatchery13 Such open spring13 systems feeding a hatchery are a misfortune that canbe expected to transmit disease so we suggest that renovating the spring again to combat13 IchImproved techniques to divert water from13 the springs and more throuough treatment ofstream-shy‐side vegetation may improve the success of chemical treatment Successful renovationwould likely both improve growth rates and reduce chemical costs associated with treating Ichoutbreaks Even13 if complete renovation13 is impossible or impractical an13 effort to reduceinvasive fish density in the springs13 which act a vector for the parasite(and thereby reduce thelikelihood of13 Ich being transmitted into ponds) may still13 show dramatic improvements

36

13

Introduction

Conservation efforts13 for razorback sucker13 (Xyrauchen texanus)13 currently13 depend on

captive rearing and stocking programs Low survival of stocked razorback suckers (Brooks

1986 Marsh13 and13 Brooks13 1989 Marsh13 and13 Pacey13 2005) has13 caused13 target sizes for stocked13

fish to steadily increase in efforts to reduce predation mortality13 (Marsh13 et al13 2005

Schooley and Marsh 2007) Rearing fish to larger sizes at hatcheries comes with increased

costs and creates the need to evaluate husbandry and rearing practices that may affect fish

growth13 We evaluated growth13 rates13 of individual razorback suckers13 in ponds13 at Bubbling

Ponds Fish Hatchery13 using Passive Integrated13 Transponder (PIT) tags13 to13 obtain13 precise

growth information for individual fish so that valid comparisons of growth rates as related

to rearing practices can be made

Due to the critical nature of the razorback sucker stocking program we did not

design experimental studies that would require major rearrangement and potentially

reduce production of hatchery operations Instead our studies used normal variation in

production techniques and practices to isolate factors that may modify growth rates

Though this methodology dramatically limits replication and may limit our ability to

directly13 attribute13 differences in growth13 rates13 to13 the13 variables13 we13 investigate13 we13 were13 able13

to accomplish research goals without altering hatchery operations or impacting

production

From13 2009 through 2011 we conducted a series of observational13 growth13 studies to

determine growth rates of individual razorbacks at Bubbling Ponds The first set of

experiments included13 identifying13 growth13 rates13 in lined13 and13 unlined13 ponds determining

growth13 rates13 of fish at different13 sizes13 in13 relation13 to sorting13 practices and monitoring

razorback growth rates after removing the source of the ectoparasite13 Ich (Ichthiopthirus

multifiliis) from13 the hatchery water source13

Razorback growth rate in lined ponds

Our first growth study documented individual growth rates at normal density in 11

million gallon lined ponds13 over two13 years13 This is the standard13 grow-shy‐out process for

razorbacks13 at Bubbling Ponds We monitored growth of fish for a variety13 of sizes and13 the13

37

13

amount of time in a pond during the growing season These13 data give a snapshot of growth13

rates13 at the13 facility13 and13 provide13 the basis for comparisons throughout our study

Growth rate13 in an unlined pond

In addition13 to 6 ponds lined with heavy plastic13 sheeting13 Bubbling Ponds Fish13

Hatchery maintains two narrow and deep (same dimensions as lined ponds13 Figure13 4)13 and13

three large13 shallow unlined ponds These earthen13 ponds typically have vegetation and

associated aquatic invertebrates that may better simulate natural environments by

providing cover and improved food diversity or quality Therefore these unlined ponds

may be expected to produce higher growth rates and potentially improved survival that is

more similar to growth rates observed in more natural grow-shy‐out facilities13 Historically13 the13

large13 shallow13 ponds have produced very large fish when13 utilized at low13 fish density13 The

narrow13 deep earthen13 ponds are13 used to grow13 fry13 at high density in their first13 year of life

The major downside to unlined ponds is the difficulty in harvesting fish where a lined

pond might take 8-shy‐1013 people13 a half13 day13 to13 harvest13 lined13 ponds13 require13 intensive13 weeding13

to allow seines to be pulled and therefore require many more personnel-shy‐hours13 In addition13

to harvest challenges the shallow earthen ponds tend to suffer from13 dissolved oxygen

crashes during the summer Unlined ponds also may maintain higher13 populations13 of non-shy‐

target species such as bluegill sunfish mosquito fish and bullfrog tadpoles We measured

growth rates of suckers in a large shallow earthen pond for comparison to growth in lined

ponds13

Figure13 4 Lined13 and13 earthen ponds13 of similar dimensions (approx 1000000 gallons first

and second panels) and a large13 shallow13 earthen13 pond (third panel)

38

13

Effect of sorting on growth

Razorback13 suckers13 are13 currently13 sorted13 after their first13 year of growth13 They are13

typically removed from13 one of the13 upper earthen13 ponds and13 split into13 two13 lined13 ponds for

subsequent grow-shy‐out13 The larger13 fish (gt approximately 140 mm) are placed into one pond

and the smaller individuals in another It is possible that the larger fish were more

aggressive or adept13 at taking food so this sorting process is intended to allow smaller fish

to improve their growth rate

Effect of Ich on razorback sucker growth rates

We13 evaluated13 growth13 rates13 of razorback sucker13 in the13 presence13 and absence of the

ectoparasite13 Ich (Ichthiopthirus multifiliis) Ich outbreaks can occur in wild populations13 but

hatcheries13 have13 proven excellent locations13 for Ich because13 of very high fish densities13 which13

facilitate13 the13 transfer13 of Ich13 between13 fish This common fish parasite causes direct mortality13

to razorback13 suckers as well13 as secondary bacterial13 infections13

The open spring and13 ditch13 which13 provides water to the Bubbling13 Ponds Hatchery

has long13 been infested with mosquitofish (Gambusia affinis) that harbor13 the13 Ich parasite13

and allow13 it13 to enter the hatchery with incoming13 water13 The solution13 to13 the13 Ich problem13

was to remove the mosquitofish host using13 Rotenone Razorback13 sucker growth13 rates were13

then tracked in13 the absence of this parasite for 4 months and compared with growth rates

after Ich returned to the pond and from13 previous years

Methods

Razorback growth rate in lined ponds

On May 14 2008 141 razorback suckers were tagged with 12 mm PIT tags (1342

kHz) and placed in Pond 3 (approximately 1100000 gallons13 Figure13 4)13 at Bubbling13 Ponds

Fish Hatchery Fifty-shy‐three of these tags were recovered two months later when a large

Ichthyophthirius multifilis (Ich) outbreak killed many fish in the pond On October 15 2008

an additional13 145 PIT tagged13 fish were13 also placed into Pond13 3 On13 May13 14 2009 Pond13 3

was harvested and a total13 of 141 PIT tagged fish were recovered13 Of the tagged fish13 26 fish

had13 been13 in the13 pond since May13 of 2008 (378 days13 o growth) and 115 had been13 in13 the

39

13 40

pond since October13 15 2008 (211 days13 of growth) Numbers of fish in Pond 3 after the Ich

outbreak and for the majority of the period of growth were between 3 000 and 4000 fish

A Hobotempreg temperature13 logger13 was13 also13 installed13 in Pond 3 one meter below the water

surface13 near13 the13 outflow and13 recorded water temperature every 3 hours to allow analysis

of the effects of water temperature on growth rate (Figure13 5) This Hobotemp data is

representative of other pond temperatures throughout this study

In a second experiment 210 adult13 razorback suckers13 were13 PIT tagged13 on13 May 14

2009 and13 placed13 into13 Pond13 3 upper to13 evaluate13 growth13 rates13 of larger13 razorback suckers13 at

Bubbling13 Ponds Hatchery13 under current13 rearing13 conditions13 Size of these fish at tagging13

was (mean = 285 mm range = 205 ndash 396 mm) These fish remained in the pond for 257

days and were harvested on Jan 25 2010 to provide information on growth rates of larger

razorback suckers13 under13 current rearing conditions

Figure 513 Temperatures (degC) inrearing pond at BubblingPonds Hatchery from July toSept 2009 (top graph)13 andfrom Nov to Dec 2009 (Lowergraph) Temperaturesrecorded with a Hobotempregremote data logger13 every 3hours

13

Growth rate13 in an unlined pond

To document razorback sucker growth in earthen ponds we introduced13 225 tagged13

razorback suckers13 into13 Pond13 1 lower13 (Figure 4) in February 3 2010 Additional tagged fish

from13 other studies were added to the pond throughout the growing season and the density

of 1 lower reached a maximum13 of nearly 7000 fish in early summer 2010 Density was

reduced to approximately 6000 fish by capturing fish with hoop nets on June 3 2010 54 of

these fish were tagged fish and returned to 1 lower after being weighed and measured The

pond was harvested on January13 2713 2011 and a total13 of 254 tagged fish out13 of 4296 fish

total were removed from13 the pond The pond was harvested on January 27 2011 (358 days13

of growth) and the tagged fish were weighed and measured Total number of razorbacks in

the pond at harvest13 was 4296

Effect of sorting practices on growth rates

On March 1113 200913 Pond13 5 upper was13 harvested13 and13 split into13 two13 separate13 groups

Two hundred of the smaller fish (average size = 122 mm TL) were PIT tagged and placed

into13 Pond13 7 upper and13 200 of the13 larger13 fish (average = 160 mm TL) were PIT tagged and

placed int Pond13 8 upper Density13 in Pond13 7 was13 4500 fish and13 in Pond13 8 there13 were13 6500

fish These ponds were then harvested after 1 year and growth rates were compared to

give information on the effects of current sorting practices Hobotempreg temperature

loggers were installed in13 Ponds 7 and13 8 during13 the13 grow-shy‐out period with13 water13

temperature recorded every 2 hours13 (Figure13 6)

Effect of Ich on razorback sucker growth rates

Bubbling Ponds spring was treated with Rotenone (CFT Legumine 5) at a

concentration of 2 ppm13 to remove all mosquitofish from13 the spring The treatment

consisted of two treatments 6 hours in duration on two consecutive days (April 12 -shy‐ 13)

using13 drip13 stations13 and13 backpack sprayers13 followed13 by13 an13 additional 6 hours13 of

detoxification using sodium13 permanganate Although 12 mosquitofish were captured in the

spring pond the week following the treatments subsequent minnow trapping (20 traps

checked13 daily13 for 3 weeks) did not capture any additional fish until August 11 2010 when

41

13

juvenile mosquitofish were again detected in the spring pond Minnow traps have

subsequently been set daily with several hundred individuals removed To evaluate if Ich

was also again present in the spring we captured 15 mosquitofish from13 the spring pond on

three separate days and placed them13 in an aquaria at 25 degC with 5 longfin dace known to be

free of Ich These fish were monitored for 2 weeks with no signs of Ich developing This

indicates that even though mosquitofish have returned to the spring pond the parasite is no

longer present13 although how13 long13 this condition13 will13 persist13 is unknown13

On May 1113 201013 200 juvenile razorback13 suckers were harvested out13 of Pond 5

upper (2009 year Class from13 Dexter National Fish Hatchery) and were PIT tagged and

placed into Pond 8 to evaluate if growth rates at bubbling ponds hatchery have improved

following the renovation of the spring and the removal of the Ich parasite Unfortunately13

on Sept13 8 2010 Ich was13 again13 detected13 in Pond 8 and the pond was immediately seined

and 74 tagged fish were measured to obtain growth information for the 4-shy‐month period

during13 which13 the13 pond13 was13 Ich-shy‐free13

Figure13 6 Temperatures (degC) in rearingponds 7 and 8 at Bubbling Ponds Hatchery13 from March 2009 ndash March 201013 pond 7(top13 graph)13 and13 pond 8 (Lower13 graph)13 Temperatures recorded with a Hobotempregremote data logger every 3 hours

42

13

Results

Growth in Lined Ponds

Razorback suckers13 that had been13 in13 Pond 8 upper for the13 entire13 year13 grew an13

average of 0263 mmday (789 mmmonth) and razorback suckers that had been in the

pond for 7 months (Oct -shy‐ May) grew13 on13 average of 028 mmday (843 mmmonth) (Figure13

7) These growth13 rates13 did not significantly13 differ Fish density13 in Pond 3 during13 the13

majority of the growth period was13 00032 ndash 00036 fishgallon13 Additionally no13 significant

differences in growth rate were observed between fish smaller than 210 mm TL and fish

larger than 210 mm TL when all recaptured fish were combined

We also measured the growth rate of very large fish in a lined pond On Jan13 2513 201013

156 adult fish with PIT tags were recovered from13 Pond 3 upper13 These fish were13 in the13

pond for 257 days and experienced an average13 growth13 rate13 of 024mmday or 73

mmmonth (Figure13 7)13 This growth13 rate13 is slightly13 lower13 than13 the13 average13 growth13 rate13

observed13 at Bubbling13 Ponds Hatchery in other studies (0275 mmday 825 mmmonth)

but may not be biologically meaningful We would expect larger13 fish to13 have13 reduced

growth rates according to a typical Von Bertalanfy growth model (Bertalanffy 1957) but it

appears that13 over the size range we evaluated (300 -shy‐ 450 mm TL) growth rates have not

slowed significantly compared to that of smaller13 fish grown at Bubbling Ponds13 Hatchery

Growth13 of razorback suckers13 is known13 to13 slow as13 fish reach13 larger13 sizes but it appears13 this13

reduced growth rate may not really start to be biologically meaningful at Bubbling Ponds

Hatchery13 until razorback suckers13 exceed 450 mm TL

Growth in unlined ponds

Growth13 rates13 for the13 fish recaptured13 during13 the Pond 1 lower13 thinning13 (120 days13 in

the pond) was 024 plusmn 003 mmday (729 plusmn 090 mmmonth) (Figure13 8)13 Fish13 that were13 in

the pond for nearly the entire year grew13 an13 average13 of 024 plusmn 001 mmday (726 plusmn 027

mmmonth) These growth rates are surprisingly the lowest measured growth rates for

any part of our study and differ significantly from13 every other measured growth rate

except very large13 fish (Figure13 9)13 Separating13 out13 large fish that13 were in13 the pond for the

entire year makes no difference fish that were added to the pond at TL lt300 mm grew

43

13

Gro

wth

Rat

e (m

md

ay)

020

026

032

0244 plusmn 001 mmday (733 plusmn 028 mmmonth) and and those with TL gt= 300 mm at the

start of the experiment grew 022 plusmn 003 mmday (651 plusmn 101 mmmonth)

Razorback Growth Rates in Lined Ponds

Figure 7 Growth ofrazorback suckers in(mmday plusmn standard error)in Pond 8 upper in 2008-shy‐2009 An ANOVA did notdetect any significantdifferences

7 Months Full Year 300+ mm fish

Effects of sorting on growth

One hundred and seventy five tagged razorback suckers were recovered from13 Pond

8 upper13 on March13 24 2010 (378 days13 of growth)13 These were13 the13 larger sorted13 fish (gt140

mm TL) that came out of Pond13 5 on March13 11 2009 One13 hundred and13 twenty13 two13 tagged13

razorback suckers were also recovered from13 Pond13 7 upper on March13 31 2010 (385 days13 of

growth)13 These were13 the13 smaller sorted13 fish (lt140 mm TL) that came out of Pond13 5 on

March 1113 200913 No significant differences in growth rate (mmday) were observed among

larger fish in Pond 8 and smaller fish in Pond 7 (pgt005 ANOVA) (Figure 10)13 indicating

that13 sorting may have helped to offset the original slower growth trajectory of the smaller

fish Temperatures of Ponds 7 and 8 upper remained similar throughout the year13 (Figure

5)

44

13

13

13

Gro

wth

Rat

e (m

md

ay)

Gro

wth

Rat

e (m

md

ay)

020

026

032

020

026

032

Razorback Growth in an Unlined Pond

Figure 8 Growth of razorbacksuckers (mmday plusmn standard error) in Pond 1 lower (an unlined pond)in 2010-shy‐2011 An ANOVA did notdetect any significant differences

6 Months 12 Months lt 300 mm Fish 300+ mm Fish Growth Growth

Lined vs Earthen Ponds 1 year of growth

Figure 9 Growth of razorbacksuckers (mmday plusmn standard error) in lined and unlined ponds A t-shy‐test13 did not detect a significantdifference

Lined Pond Unlined Pond 1 Yr Growth 1 Yr Growth

45

13

Effect of Sorting G

row

th R

ate

(mm

day

) G

row

th R

ate

(mm

day

)

032

020

026

032

020

026

Smaller Fish Larger Fish

Effect of Ich

Figure 10 Average growthof razorback suckers(mmday plusmn standard error)that were size-shy‐sorted intosmall fish (pond 7) and largefish (pond 8) populations At-shy‐test did not detect asignificant difference

Figure 11 Average growth ofrazorback suckers (mmday plusmnstandard error) after Ich wasremovd from the hatcheryrsquos springand after Ich was again detected inthe pond The growth rate withoutIch is significantly higher than boththe rate after Ich and the ourstudyrsquos average annual growth ratein lined ponds (ANOVA p =00003)

Growth without Ich Growth With Ich Average Annual 4 months 4 months Growth Rate

46

13

Effect of Ich on razorback sucker growth rates

Seventy-shy‐four13 tagged13 razorback suckers13 were13 recovered from13 Pond 8 on September

15 2010 These fish had13 been13 in the pond for 4 months and experienced a growth rate of

032 mmday or 97 mmmonth (Figure13 11)13 This growth13 rate13 is significantly higher (p =

005 two sample t-shy‐test) than the mean growth rate for the same group13 of tagged fish after

Ich detection (022 mmday or 65 mmmonth) and significantly higher than any other

individual growth13 rates13 observed13 to13 date13 at Bubbling13 Ponds Hatchery13 (Figure13 11)13 If this13

growth13 rate13 were13 extended throughout13 the entire13 year13 fish on average from13 Ich-shy‐free13 ponds13

would be 16 mm longer than fish from13 ponds infested with Ich Studies conducted at

Bubbling Ponds hatchery in 2008 (Ward 2008) did not reveal any effects of the treatment

chemicals on razorback sucker growth rates so it13 is likely that13 the parasite outbreaks

themselves are causing reducing growth rates rather than the chemicals used to treat the

parasites13

Conclusions

Our results suggest that under typical hatchery operations (maximizing number of

fish produced)13 the growth13 rate13 of razorback13 suckers13 is relatively13 consistent at Bubbling13

Ponds hatchery13 at 02-shy‐03 mmday (6-shy‐9 mmmonth)13 but is lower than growth13 rates13 at

other13 facilities (02 ndash 18 mmday Ward et al 2007)13 This growth13 rate13 has13 been13 constant in

both lined and unlined ponds and at all fish densities we were able to measure To achieve13

growth13 rates13 substantially higher than this will likely require13 significant changes in rearing

practices that may not be practical in order to reach numerical production13 goals

Temperature is a key variable in fish growth but seasonal growth patterns

described13 above13 (Figure13 5) demonstrate that water temperatures are high enough in

winter to maintain razorback growth Differences in water temperature by season

currently13 do not fluctuate more than 10degC at Bubbling Ponds because of the continuous

supply of water flowing through each pond (approx 225 gallonsmin) These high water

flows appear to keep pond temperatures within the thermal preference13 for razorback

suckers13 (1213 -shy‐ 28 degC Bulkley and Pimentel 1983) throughout the entire year with

temperatures rarely dropping13 below 16deg13 C (Figures 513 6)13

47

13

Fish density is another key variable in fish growth and though the number of fish in

a pond during our study ranged from13 3000 to 700013 fish we13 did not find any13 correlation13

between13 density and growth rate13 This might yield two conclusions First13 razorback

growth13 may be changed equally13 by13 densities13 at the13 hatchery13 (ie13 a density13 of 3000 fish in a

pond is as stressful13 for razorbacks as a density13 of 7000 fish) An alternative is that other

factors13 such as disease outbreaks have13 stronger13 control over fish growth13 than13 density13

Fish density13 would13 have13 to13 be13 experimentally manipulated to test13 this13 and hatchery

operations (producing the maximum13 number of fish) prevented our manipulating density13

in ponds for this13 work The trouble with manipulating density demonstrates the difficulties

associated with changing13 hatchery13 practices experimenting with density would have

prevented BPH from13 meeting13 production13 goals Given that the stocking of smaller

razorbacks has met with very little success perhaps BPH goals could be changed from13

producing 12000 fish at 300+ mm per year to a smaller number of very large fish each

year Growing13 fewer13 larger13 fish could potentially be accomplished in the same time frame

as more smaller fish but a better understanding of how density alters growth rate would

be required to be confident13 of this

The very slow growth13 in the13 earthen13 unlined13 Pond 1 lower13 was very surprising We13

had13 anticipated13 that the13 diversified diet13 cover and13 other13 habitat features13 provided by13

unlined ponds would yield dramatically increased growth rates However these traits were

not enough to offset high fish densities and in fact the unlined pond in our study13 suffered

mortality to bring densities down to that observed normally in lined ponds

Our data13 suggest13 that razorbacks13 sucker13 growth13 rates13 are13 higher in lined13 ponds13

However we13 think the reasons13 for the13 very slow growth we observed13 in the13 unlined13 pond13

in our study13 is instead13 linked13 to13 the13 usage13 of Pond 1 lower13 during13 the13 study13 rather13 than13

intrinsic13 slow growth13 in earthen13 ponds First the pond was at extremely high density for at

least part of the study The volume of Pond 1 lower has not been estimated but hatchery

managers suggest 1500-shy‐2000 fish is an appropriate number of individuals so this pond

was at a very high density for much of the experiment Second dissolved oxygen is often

very low in the13 large13 earthen13 ponds during the heat of summer much lower than that of

lined ponds This will both limit the number of fish that can survive in the pond and almost

certainly13 increases stress13 of these13 fish potentially13 reducing growth13 The DO crashes also13

48

13

limit the amount of feed hatchery managers can give fish in these ponds sometimes for

days or weeks at a time which further reduces growth during warm13 weather

Our data13 suggests that13 growth rates at the Bubbling13 Ponds Fish Hatchery are likely

as high as possible given13 the pond densities required to meet production goals and the Ich-shy‐

infested water that feeds the facility Sorting practices are successful in helping as many

fish as possible reach stocking length as fast as possible Unlined ponds may be able to

grow13 large13 fish at low13 densities13 but whatever factors allow13 for that13 growth are not13 able to

overcome high fish density The removal of invasive13 fis that act as13 a host for the13 parasite13

Ich fish from13 the Bubbling13 Ponds spring13 allowed the highest13 growth rate at 032 mmday13

(96 mmmonth) but that growth rate decreased again as Ich re-shy‐infested13 the13 hatchery13

Consistently13 achieving13 growth13 rates13 as high or substantially13 higher than13 this13 will likely13

require13 significant changes in rearing practices that may not be practical in order to13 reach13

numerical production13 goals

Two major changes that might result in higher growth rates are substantially

reducing fish density and modifying the way spring water is delivered to the facility (via

either repeated chemical treatments or enclosed concrete water diversions) to eliminate

Ich from13 the hatchery source water Other potential changes not address by our work

include13 flow-shy‐training razorbacks much previous literature including MSCP-shy‐funded13 work

on razorback suckers13 suggests13 that fish growing13 in flowing water will grow13 faster than fish

in still water (Jorgensen and Jobling 1994) Furthermore there are a wide variety of

potential benefits associated with growing13 fish13 in flowing13 water in addition13 to increased

growth13 rates13 (Davidson13 199713 Castro13 et al13 2011) Another option13 for increasing13 growth13

rates13 include13 changing to13 intensive13 culture13 in large circular13 tanks

Finally given that the stocking of smaller razorbacks has met with very little

success13 perhaps13 BPH13 goals13 could13 be13 changed from13 producing 12000 fish at 300+ mm per

year to a smaller number of very large fish each year Growing fewer larger fish could

potentially be accomplished in the same time frame as more smaller fish but a better

understanding13 of how density13 alters growth13 rate13 would13 be13 required to13 be13 confident of this

49

13

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower13 Colorado13 River Multi-shy‐Species13

Conservation Program13 (LCRMSCP) under Work Task C10 We13 thank Ty Wolters13 Tom13

Burke13 and Eric13 Volkman for their support of this research and Frank Agygos and Dave

Billingsly13 of the Bubbling13 Ponds Fish Hatchery13 for their willingness to participate in13 this

research13 and13 for their technical assistance We also thank the LCRMSCP fish group from13

Boulder City13 NV for their assistance with harvesting13 ponds and tagging13 fish13

50

13

Literature13 CitedAnders P J 1998 Conservation aquaculture and endangered species can objective science13

prevail13 over risk13 anxiety Fisheries 23(11) 28-shy‐31

Anderson R O and R M Nuemann 1996 Length weight and associated structural indicesPages 447 ndash 482 in B R Murphy13 and D13 W Willis13 editors13 Fisheries techniques13 2ndedtion American Fisheries13 Society13 Bethesda13 Maryland

Bain M B J T Finn and H E Brooks 1988 Streamflow regulation and fish communitystructure13 Ecology13 69382-shy‐392

Bays J H Zarbock R Whitman and T Murphy 2005 Conceptual design and managementof native13 fish refugia on the13 lower13 Colorado13 River In13 CL Spring13 and13 S Leoneditors Proceedings of two symposia Restoring native fish to the lower ColoradoRiver13 interactions13 of native and non-shy‐native13 fishes 13ndash1413 July13 1999 Las13 Vegas13 Nevada13 Restoring13 natural function within a modified riverine environment thelower Colorado River13 8ndash913 July13 1998 U S Fish and13 Wildlife13 Service Southwestern13 Region Albuquerque New Mexico Pages 167-shy‐177

Bertalanffy L Von 1957 Quantitative laws in metabolism13 and growth13 Q Rev Biology 32217 ndash 231

Bingham T B Scheer and C McAda 2003 Propagation facilities in Grand Valley (24 RoadHatchery Horsethief13 Ponds and13 grow-shy‐out ponds) for captive13 rearing13 ofendangered13 fishes for the13 upper13 Colorado13 River basin13 Colorado River RecoveryProgram FY2003 annual project report13 US Fish and13 Wildlife13 Service GrandJunction13 4pp

Birchell G J and K Christopherson 2004 Survival growth and recruitment of larval andjuvenile razorback13 sucker (Xyrauchen texanus) introduced13 into13 floodplain13 depressions13 of the13 Green River Utah13 Final report13 Upper13 Colorado13 RiverEndangered Fish Recovery Program13 Project No C-shy‐6RZ Publication Number 04-shy‐1513 Utah13 Division of Wildlife13 Resources Salt Lake13 City13 Utah13 67 pages

Brannon E L 1993 The perpetual oversight of hatchery programs Fishery Research 1819-shy‐27

Brett J R 1979 Environmental Factors and growth pages 599-shy‐67513 InW S Hoar13 D13 J13 Randall and J R Brett (eds) Fish Physiology Volume 8 Bioenergetics and GrowthAcademic Press New York

Brooks J E 1986 Annual reintroduction and monitoring report for razorback suckerXyrauchen texanus in the Gila River Basin Arizona 1985 US Fish and WildlifeService13 Offices of Endangered13 Species and Fishery13 Resources Albuquerque 23 pp

51

13

Brunson13 R E and K D13 Christopherson13 200513 Larval13 razorback13 sucker and bonytailsurvival and13 growth13 in the13 presence13 of nonnative13 fish in the13 Baeser13 floodplainwetland of the middle Green River Final report prepared for Upper13 Colorado RiverBasin Endangered Fish Recovery Program Project No C-shy‐6-shy‐rz-shy‐bt Publication13 No 05-shy‐26 Utah13 Division of Wildlife13 Resources13 Vernal13 32 pp

Bulkley R V and R Pimentel 1983 Temperature preference and avoidance by adultrazorback suckers Transactions of the American Fisheries Society 112601-shy‐607

Burke13 T13 199513 Rearing13 wild razorback13 sucker larvae in13 lake-shy‐side13 backwaters13 LakeMohave ArizonaNevada Proceedings of the Desert Fishes Council 2635

Busacker G P I R Adelman and E M Goolish13 199013 Growth13 Pages 363 ndash 387 in C BSchreck and p B Moyle editors Methods for fish biology American FisheriesSociety Bethesda Maryland

Castro V B Grisdale-shy‐Helland S J Helland T Kristensen S M Jorgensen J Helgrud13 GClaireaux A P Farrell A Krasnov and H Takle 2011 Aerobic training stimulatesgrowth and promotes disease resistance in Atlantic salmon (Salmo salar)Comparative Biochemistry and Physiology -shy‐ Part A Molecular amp IntegrativePhysiology13 160(2) 278-shy‐290

Czapla T E 2002 Facilities plan for the production of endangered fishes to meet statestocking13 plans13 as13 part of the13 Upper13 Colorado13 River Endangered13 Fish RecoveryProgram Upper Colorado River Basin Recovery Implementation Program US Fishand Wildlife Service13 Denver13 9 pp

Davidson W 1997 The effects13 of exercise13 training on teleost fish a review of recentliterature Comput Biochem Physiol 117A67ndash75

Figiel Jr C R 2005 Annual report fiscal year 2004 Willow Beach National13 Fish HatcheryUS Fish and Wildlife13 Service Willow Beach 17 pp

Figiel Jr C R M E Ulibarri G Carmichael J Seals and J N Hanson 2005 Intensive13 fish13 culture of warmwater native fishes at a coldwater fish hatchery Pages 164-shy‐16613 inProceedings of two symposia restoring native fish to the lower Colorado13 River13 interaction13 of native13 and13 non-shy‐native13 fishes July13 13-shy‐1413 1999 Las Vegas Nevada USFish and Wildlife Service Southwest Region Albuquerque New Mexico

Gerking13 S D 1978 Ecology of freshwater fish13 production13 Halstead Press13 New13 York

Gustafson W and Q Bradwisch 2000 Wahweap operation and maintenance -shy‐-shy‐ UtahColorado River Recovery Program FY 2000 annual project report Project No 29cUtah13 Division of Wildlife13 Resources Page AZ 3pp

52

13

Hamman R L 1985 Induced spawning of hatchery-shy‐reared13 razorback sucker ProgressivFish Culturist 47(3) 187-shy‐189

Hanson J N 1996 Annual report fiscal year 1996 Willow Beach National Fish HatcheryUS Fish and Wildlife Service13 Willow Beach 9pp

Irving D S Seversen and M Montagne 2004 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2004 annual project13 report Report No 29b US Fish and13 Wildlife13 Service Vernal 3pp

Jorgensen E H and13 M Jobling 1994 Feeding and13 growth13 of exercised13 and13 unexercised13 juvenile Atlantic salmon in freshwater and performance after transfer to seawaterAquaculture International 2 154-shy‐164

Kaeding L R and D B Osmundson 198913 Colorado13 Squawfish13 and13 razorback sucker grow-shy‐out pond studies as part of conservation measures for the green mountain andRuedi reservoir water sales Final report for agreement number 6-shy‐AA-shy‐60-shy‐00150

Koebele13 B P13 198513 Growth and the size hierarchy effect an experimental assessment ofthree proposed mechanisms activity differences disproportional food acquisition13 pysiological stress Environmental Biology of Fishes 12 181-shy‐188

Kretschmann A E and L L Leslie 2006 Razorback sucker (Xyrauchen texanus) status13 reproduction and recruitment in Senator Wash Reservoir CA Final Report13 to USBurea of Reclamation Cooperative Agreement No 00-shy‐FG-shy‐34-shy‐ 0009 p 32 ArizonaGame and Fish Department Phoenix

Marsh13 P13 C13 1987a13 Digestive tract13 contents13 of adult razorback suckers13 in Lake13 MohaveArizona-shy‐Nevada Transactions of the American Fisheries Society 116117-shy‐119

Marsh P C 1987b Native fishes at Buenos Aires National Wildlife Refuge and ArizonaState University Research Park Arizona opportunities for management researchand public13 education13 on13 endangered species13 Proceedings of the Desert13 FishesCouncil 1967-shy‐78

Marsh P C 1994 Rearing native Colorado River fishes in golf course ponds Arizona StateUniversity Tempe 22 + pages

Marsh13 P13 C13 200013 Fish population13 status and evaluation13 in13 the Cibola13 High Levee PondFinal report agreement number 99-shy‐FG-shy‐30-shy‐00051 US Bureau of ReclamationBoulder City13 Nevada13 20 pages

Marsh P C and C A Pacey 1998 Growth of wild adult razorback suckers13 in Lake13 Mohave13 Arizona-shy‐Nevada13 Final report13 US Bureau of Reclamation Boulder City Nevada 25pages + appendices

53

13

Marsh P C B R Kesner and C A Pacey 2005 Repatriation as s management strategy13 to13 conserve a critically13 imperiled fish species North American Journal of FisheriesManagement 25 547-shy‐556

Marsh P C and C A Pacey 2005 Immiscibility of native and non-shy‐native13 fishes Pages 59-shy‐63 inMJ13 Brouder13 CL13 Springer13 and CS13 Leon13 editors13 Proceedings of two13 symposia Restoring native fish to the lower Colorado River interactions of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 NV and13 Restoring natural13 function within a modified riverine environment the lower Colorado River13 July13 8-shy‐913 1998 Las Vegas NV US Fish and13 Wildlife13 Service Southwest Region AlbuquerqueNew Mexico

Marsh13 P13 C13 and J13 E Brooks13 198913 Predation13 by ictalurid catfishes as a deterrent13 toreestablishment of hatchery-shy‐reared13 razorback sucker The Southwestern Naturalist34188-shy‐195

Matthews R A 2005 Ichthyopthirus multifiliis Fouquet and Ichthyopthirosis infreshwater13 teleosts13 Pages13 159-shy‐218 in Advances in Parasitology volume 59 J RBaker R Muller D Rollinson (eds) Academic Press

McCarthy13 M S and W L Minckley 1987 Age estimation for razorback sucker (PiscesCatostomidae) from13 Lake Mohave Arizona and Nevada Journal of the Arizona-shy‐Nevada Academy of Science 2187-shy‐97

Minckley13 W L13 198313 Status of the razorback13 sucker13 Xyrauchen texanus (Abbot)13 in13 thelower Colorado River basin13 The Southwestern13 Naturalist13 28(2) 165-shy‐187

Minckley13 W L13 199113 Native fished of the Grand Canyon13 region an obituary13 Pages 124-shy‐177 in Colorado River ecology and dam13 management National Academy PressWashington13 DC

Minckley13 C13 O and M LaBarbara13 199913 Report13 on13 native fish grow-shy‐out facilities13 at Cibolaand Imperial National Wildlife Refuges 1993-shy‐199513 US Fish and13 Wildlife Service13 Parker Fishery Resources Office Parker Arizona

Modde13 T13 199613 Juvenile razorback sucker (Xyrauchen texanus) in a managed wetlandadjacent13 to the Green13 River13 Great13 Basin13 Naturalist13 56375-shy‐376

Modde T KP Burnham and E J Wick 1996 Population status of the razorback sucker13 inthe middle Green River (USA) Conservation13 biology 10 110-shy‐119

Modde13 T13 and G13 B Haines13 200513 Survival13 and growth of stocked razorback13 sucker andbonytail in multiple floodplain wetlands of the middle Green River under resetconditions13 Final report prepared for Upper Colorado13 River13 Basin RecoveryImplimentation Program US Fish and Wildlife Service Vernal 66 pp

54

13

Modde T Z H Bowen and D C Kitcheyan 2005 Spatial and temporal use of a spawning13 site in the middle Green River by wild hatchery-shy‐reared13 razorback suckers13 Transactions of the American Fisheries Society 134937-shy‐944

Mueller13 G13 199213 The native fish work13 group13 -shy‐ a multiagency endeavor to improve thestatus of the razorback sucker in Lake Mohave AZ-shy‐NV13 Proceedings of the DesertFishes Council 2369

Mueller G 1995 A program13 for maintaining the razorback sucker in Lake MohaveAmerican Fisheries Society Symposium 15127-shy‐135

Mueller13 G13 200613 Ecology of the bonytail13 and razorback13 sucker and the role of offchannelhabitats13 in their13 recovery Scientific13 investigations13 report 2006-shy‐5065 US GeologicalSurvey13 Denver

Mueller G and E Wick 1998 Testing of golf course ponds at Page Arizona for suitability13 as grow-shy‐out facility for razorback sucker using surplus fish from13 Ouray NationalFish Hatchery National Park Service US Fish and13 Wildlife13 Service and UtahDivision of Wildlife13 Resources 28 pages

Mueller13 G13 and T13 Burke13 200513 Survival13 of young13 razorback13 sucker (Xyrauchen texanus) inrelation to13 stocking rates13 (fishha)13 and13 in the presence13 or absence13 of predatorcommunities in Lake Mohave Arizona-shy‐Nevada13 Pages13 155-shy‐16313 in Proceedings of two13 symposia restoring native fish to the lower Colorado River interaction13 of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 Nevada US Fish and Wildlife13 Service Southwest Region Albuquerque New Mexico

Mueller13 G13 J13 Carpenter13 and P13 C13 Marsh13 200413 Cibola13 High Levee Pond annual report 2004US Geological Survey Fort Collins13 Science Center13 Colorado13 and Arizona StateUniversity Tempe 23 pages

Nesler T P K Christopherson J M Hudson C W McAda F Pfeifer and T E Czapla 2003An integrated stocking plan for razorback sucker bonytail and Colorado13 pikeminnow for the Upper Colorado River Endangered Fish Recovery ProgramAddendum13 to State Stocking Plans Upper Colorado River Basin Recovery13 Implementation Program 12 pp

Papoulias13 D and W13 L Minckley13 1992 Effects13 of foo availability13 on survival and growth13 of larval razorback suckers13 in ponds Transactions of the American Fisheries Society121340-shy‐355

Paukert13 C P D L Ward13 P J Sponholtz13 and K13 D Hilwig13 Effects13 of repeated hoopnetting13 on bonytail chub13 Journal of Freshwater13 Ecology13 20(4) 649-shy‐653

Pfeifer F M13 C Baker13 and M13 Montagne13 199913 Propagation13 facilities13 in the13 Grand Valley13 (24 Road13 Hatchery13 Horsethief13 Ponds and13 grow-shy‐out ponds) for captive rearing of

55

13

endangered13 fishes for the13 Upper Colorado13 River Basin13 Colorado13 River Recovery13 Program FY 99 annual project report Project No 29a13 US Fish and Wildlife Service13 Grand13 Junction13 5pp

Pfeifer F S Seversen and M Montagne 2003 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2003 annual reportProject No 29b13 US Fish and Wildlife13 Service Vernal13 4pp

Rabago-shy‐Castro J L Sanchez13 J G Perez-shy‐Castaneda R and13 Gonzalez-shy‐Gonzlez A 2006Effects of the prophylactic use of Romet-shy‐3013 and13 copper13 sulfate13 on growth13 condition13 and feeding13 indicies in13 channel13 catfish (Ictalurus punctatus) Aquaculture 253 343-shy‐349

Reinitz GL L E Orme and F N Hitzel 1979 Variations of body compositio and growth13 among strains of rainbow trout Transactions of the American Fisheries Society 108204-shy‐207

Ruppert13 J13 B P B Holden13 and P D Abate 1999 Age estimation and growth of razorbacksucker13 Xyrauchen texanus in Lake13 Mead Nevada Proceedings13 of the Desert FishesCouncil 3040

Schnoor K D and J Logan 2002 Operation and maintenance of JW Mumma nativeaquatic13 species restoration facility Colorado Colorado River Recovery Program FY2002 annual project report13 Project No 29d Colorado13 Division of Wildlife Alamosa3pp

Salisbury13 L13 1998 Factors13 affecting razorback13 sucker growth13 in Lake13 Mohave backwaters13 MS Thesis13 Unviersity13 of Nevada13 Las13 Vegas

Schooley J13 D13 and P C13 Marsh13 2007 Stocking of endangerdd13 razorback13 suckers13 in thelower Colorado River Basin13 over three decades 1974-shy‐2004 North American Journalof Fisheries Management 27 43-shy‐51

Severson S H H M Tyus and G B Haines 1992 An evaluation of feeds for raisingrazorback sucker Xyrauchen texanus Journal of Applied Aquaculture 155-shy‐65

Toney D P 1974 Observations13 on the13 propagation13 and13 rearing13 of two13 endangered species13 in a hatchery environment Proceedings of the Annual Conference of the Western13 Association of State Game and Fish Commissions 54 252-shy‐259

Tyus H M13 1998 Razorback sucker13 (Xyrauchen texanus) recovery plan13 University13 ofColorado Center for Limnology Boulder13 76 pages

Tyus H M13 and13 S H Severson 1990 Growth13 and13 survival of larval razorback suckers fedfive formulated diets The Progressive Fish Culturist 52197-shy‐200

56

13

Ulibarri M E 2003 Annual report fiscal year 2001 Dexter National Fish Hatchery13 andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 26 pages

Ulibarri M E 2003 Annual report fiscal year 2002 Dexter National Fish Hatchery andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 59 pages

USBR 2006 Lower13 Colorado13 River Multi-shy‐Species Conservation Program final fishaugmentation plan Boulder City 19 pp

USFWS 2002 Razorback sucker (Xyraouchen texanus) recovery goals Amendment andsupplement to the Razorback Sucker Recovery Plan13 US Fish and Wildlife Service13 Region 6 Denver13 Colorado

USFWS 1999 Annual report 1999 Ouray National Fish Hatchery Vernal 25pp

USFWS 2004 Management plan for the big-shy‐river13 fishes of the13 lower13 Colorado13 river basinamendment and supplement to the bonytail humpback chub Coloradopikeminnow and razorback sucker recovery plans

USFWS13 2005 Station13 profile13 of the13 Dexter13 National Fish Hatchery13 and Technology CenterUS Fish and Wildlife13 Service Dexter

Valdez R A P G Mangan R Smith and B Nilson 1982 Upper Colorado River fisheriesinvestigations13 inW H Miller J J Valentine D L Archer H M Tyus R A Valdezand L13 Kaeding13 editors13 Colorado River Fishery13 Project13 Part 2 Field13 investigations13 US Bureau of Reclamation Salt Lake City Utah

WBNFH 2004 Culture methods of the endangered razorback sucker Xyrauchen texanusUS Fish and Wildlife13 Service Willow Beach National Fish Hatchery13 8 pp

Ward D 2008 Effects of disease treatments on growth of razorback sucker ReportSubmitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 Inpartial fulfillment of work task C10 agreement number 06FG30039

Ward13 D13 M Childs and W Persons 2007 Factors13 affecting13 growth13 of razorback sucker13 (Xyrauchen texanus) in captivity Literature review and knowledge assessmentReport Submitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 In partial fulfillment of work task C10 agreement number 06FG30039

57

Appendices

Appendix 1 Survey Questions Survey of Razorback Sucker Culture in the

Southwestern United States

The enclosed survey is being distributed by the Arizona Game and Fish Department to razorback sucker culture facilities throughout

the Southwestern United States The purpose of this survey is to consolidate information regarding culture of this species so that

appropriate facility improvements can be considered for Bubbling Ponds Hatchery in Arizona Specifically we wish to increase

growth rate and production efficiency at the hatchery Information gathered in this survey will be summarized in a final report to US

Bureau of Reclamation in Boulder City NV and disseminated to all facilities that participate in the survey A workshop to discuss

the findings of this study as well as to share general information concerning razorback sucker culture will be organized by the

Arizona Game and Fish Department at the conclusion of this study and all participants will be invited

Thank you for taking the time to fill out this survey Please contact Mike Childs if you have questions or would like to discuss the

survey

Mike Childs

mchildssedonanet

(928) 639-1346

(928) 634-1279

Facility_____________________________________ Date___________________

Contact Phone _____________________________

ContactPerson_______________________________

Contact Email _______________________________

1 Water quality ranges at this culture facility

Season

Spring (Mar-May) Summer (Jun-Aug) Fall (Sept-Nov) Winter (Dec-Feb)

Temperature (C)

PH

DO (mgL)

PO4 (mgL)

TDS (mgL)

Hardness (mgL)

CaCO3

Pathogens

37

13

Table 2 Facilities available at major razorback sucker fish hatcheries

$amp( )$+(-+( 0(1(2$amp3amp(( 4-56+ amp7(8-+1$(9+( lt3-5( 8=$33( 23gt(805(

$amp()amp+(-(012345( 0(0+amp(A(BBCC(05 ampD(ED F CGBH IACCCACCC BJH K$+L(0D

amp$+(M$gt$ O-$+(+($P

B N B

CGBH IACCCACCC BABHC FANCC

BJH

Qamp+-3$+($P F FHC 637134(801amp0$(-(012345( H(L$33gt($O-amp1+(gt33A(

BCCC(05 ampDRK$+L(0D amp$+(M$gt$ M$-3$+($P Qamp+-3$+($P Qamp+-3$+($P

9O-$+amp$

SF S BC SC HC TC

CGI((IGC( HAHCC HSC IBC BCC IC

9O-$+amp$ BC SC 940amp+(amp21amp(8013(-(-02$15( U-ampamp0$3(D+ampPamp(gt$+ Qamp+-3$+($P IS VCC IB

W+Lamp1(+$+amp(0D( E-50D(+ampX+(gt$+( Qamp+-3$+($P JT BCC H K$+L(ED T CGBH(Y(CGH(

lt405(801amp0$(-(012345( J(L$33gt(gt33A(FCC(05( ampD(0D BS CGIBH(Z(CGBH( IC Qamp+-3$+($P NC IBC H Qamp+-3$+($P BJ VCC IC((IH

=$$gt(302(801amp0$(-(012345( 3$+(L$D(Q3+$D( MampX+(gt$+( amp$+(M$gt$ N IAHCC

amp$+(M$gt$ IF IFACCC 9O-$+amp$ FC IC

0$+3(801amp0$(-(012345( B([0(9O-amp1+()33A( IHCC(05 ampD(0D II I

K$+L(0D amp$+(M$gt$ amp$+(M$gt$

NJ B IB

GBH(Y(IGC( FAHCC IACCC

Qamp+-3$+($P Qamp+-3$+($P

IB N

BCC NACCC

12

13

Table13 3 Water13 quality13 ranges13 at each13 culture facility$amp ($)$++) -+$

-)amp012$)32$45 -6+)01763865 9$01-+3lt5 =amp+)01gt+39+5 $amp()amp+ ++)$6)+01A5

J gtLNL01O5 8P$ampamp401O5 ($Q+

BC3DE DD3DF BG3DB KLM3MLE KLH3MLI KLH3MLF CLM3BFLE CLM3BFLE CLM3BFLE

RQS0Aamp$ RQS0Aamp$ RQS0Aamp$ )ampQTamp$ )ampQTamp$ )ampQTamp$

8+)$O(6+T$ 8+)$ 8+)$ A6$)amp A6$)amp A6$)amp

BH3BI KLH3MLE CLM3BFLE

RQS0Aamp$ )ampQTamp$ 8+)$ A6$)amp

-01 ++)$6)+01A5 J gtLNL01O5 8P$ampamp401O5 ($Q+

BK3DE DD3DM BK3DE KLC3MLC KLC MLC DLM3GLK DLM3GLK DLM3GLK BIC3BMM BIC3BMM BIC3BMM

2ampamp$03040UQ$0amp0)6Q0amp0UampQ0ampamp0VampQ

BE3BI KLC

DLM3GLK BIC3BMM

213amp+(4amp50amp ++)$6)+01A5 J gtLNL01O5 8P$ampamp401O5 ($Q+

DH3DC DH3DC DH3DC KLK3MLE KLK3MLE KLK3MLE KLE3KLC ILC3KLE ILE3ILC BEE BEE BEE

+0$0amp+amplt+066)+0V$ampamp4S0RQ0$0)TP0T

DH3DC KLK3MLE FLC3ILC BEE

6137 ++)$6)+01A5 J gtLNL01O5 8P$ampamp401O5 ($Q+

BB3DC BB3DC BB3DC KLF3MLD KLF3MLD KLF3MLD CLE3BD CLE3KLD CLE3KLD BBG BBG BBG Aamp$ Aamp$ Aamp$

BB3DC KLF3MLD CLE3KLD BBG Aamp$

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Bubbling Ponds State13 fish Hatchery13

Bubbling Ponds Fish Hatchery in Arizona does not maintain razorback sucker

broodstock on site Razorback suckers are received either as juveniles from13 Willow Beach

National Fish Hatchery13 or as13 newly-shy‐hatched larvae from13 Dexter13 National Fish Hatchery

Larval fish are13 typically13 placed13 into13 an unfertilized unlined 0613 acre13 pond13 in the13 spring In

September the pond is harvested by draining the pond and seining All fish that have

reached the target size (300 mm TL) are stocked Fish that are too small to stock are split

up equally between the six remaining grow-shy‐out pond at an13 average13 density13 of about 5000

ndash 7000 fish per pond Fish are fed by hand at approximately 25 body weight split

between morning and evening feedings Fish are either fed a catfish diet made by Rangenreg

13

13

that is enriched with spirulina and krill or razorback sucker diet made by Silvercupreg

depending on availability Fish are monitored visually and by sampling using a cast net

When a large number13 of fish have13 grown to13 the13 target size they13 are13 harvested13 by13 draining

the pond and seining13 Fish are again13 sorted by hand and the largest13 fish are stocked13 Fish

that13 have not13 reached the target13 size are returned to the ponds for further grow-shy‐out13 On13

average it13 takes one to two years for fish to reach the target13 size with fish growing13 an

average of 06 mmday Target numbers for production are 12000 razorback suckers

annually (300 mm TL) The biggest difficulty in rearing razorback suckers at Bubbling

Ponds13 Fish Hatchery13 is protozoan13 parasite13 infestations13 (Ich) and13 associated13 bacterial

infections that come from13 an open spring source that is inhabited by mosquitofish

Dexter National Fish Hatchery13

Dexter National Fish Hatchery maintains four separate razorback sucker13

broodstocks13 These fish are spawned on13 site and larval13 fish are placed directly into 01 acre

ponds at a density13 of about 20000 larvae13 per pond (50 ndash 100 thousand13 per13 acre)13 Ponds

are fertilized with alfalfa13 pellets and superphosphate two weeks prior to receiving13 larvae to

produce13 natural13 feed for larval13 fish13 Ponds are13 fertilized again with alfalfa13 pellets one week

after larvae are introduced13 Fish are fed a catfish starter diet13 (sizes 1-shy‐3) made by Rangenreg

that13 is enhanced with spirulina13 and krill13 and then switched over to the razorback13 diet13 once

they are large enough to eat 1mm13 crumble Fish are fed twice a day by hand four days a

week13 at 25-shy‐60 body weight Feed ration is decreased if excess feed is seen remaining

on the13 pond bottom13 following feedings Fish are not graded or sorted during this grow-shy‐out

period Razorback suckers are harvested in the fall by draining ponds completely Fish are

sorted13 at harvest and13 distributed13 to13 other13 facilities13 for further13 grow-shy‐out depending on13

current size requirements Razorback suckers are on average 100 ndash 200 mm TL after the

first growing13 season13 and13 generally13 take13 1 -shy‐18 months for a majority of the fish to reach

300 mm TL There are 16 different species of fish maintained at Dexter National13 Fish13

Hatchery13 and13 having sufficient pond13 space13 to13 grow out separate13 groups13 of fish is the13

limiting factor for production of razorback suckers at this location

14

13

Grand Valley13 Native13 Fish Facility13

The Grand Valley Native Fish Facility maintains its own brood stock13 in13 eight13 ponds

located at the Horsethief Basin Wildlife Area in Grand Junction Colorado Fish are

spawned13 on site13 and13 larvae13 are13 reared13 indoors in fiberglass13 tanks13 at the13 24-shy‐Road13 Fish13

Hatchery13 in Grand13 Junction The 24-shy‐Road13 Hatchery13 consists of two13 separate13 recirculating13

systems that operate using de-shy‐chlorinated13 city13 water13 and two13 large13 fluidized-shy‐ bed sand

filters13 and13 rotating-shy‐drum13 filters for waste removal Fish are held in 4-shy‐foot (n=78) or 8-shy‐foot

(n=14) diameter fiberglass tanks Larval fish are started on prepared feeds immediately

after swim-shy‐up and fed exclusively razorback feeds made by Silvercupreg Fish are started on

a 0-shy‐250 micron razorback diet for the first 10-shy‐1213 days13 and13 then13 fed with13 gradually13

increasing13 feed sizes based13 on observations of feeding13 (250 ndash 400 micron 1 starter) Feed

sizes are mixed when transitioning to the next larger feed size These razorback diets are

specially sifted by Dr Rick Barrows (USDA13 Hagerman experiment station Idaho)

Razorbacks13 are13 typically eating 1mm13 extruded pellets by the time they are 35 to 4 inches

in length Fish are fed approximately 70 body weight per day initially and then gradually

reduced to 15 body weight by the time they reach the 300 mm TL target size Fish are

fed seven days13 a week using13 12-shy‐hr13 belt feeders It takes13 12-shy‐16 months to grow fish to the

target13 size in13 the hatchery13

Razorback suckers are sorted after three months and culled to about 4000 fish per

family lot Culled fish are stocked into leased grow-shy‐out ponds Stocking densities for

juveniles in these ponds is based on previous13 stocking and harvest13 rates13 and is pond

specific13 Grow-shy‐out ponds are13 harvested13 periodically13 using Fyke13 nets13 or trap13 nets13 and13 fish of

the target size are stocked Disease problems (Ich Lernea) water quality problems (low

DO) and difficulty in removing all of the fish are challenges for grow-shy‐out of razorback

suckers13 in these13 natural ponds13

Fish reared13 in the13 24-shy‐Road facility are sorted again at four to five months of age into

small and large size groups to obtain more uniform13 growth rates Batch estimates of fish

weight are done every month for each tank A group of fish are weighed and counted to

give an average weight for the tank with lengths estimated based on a lengthweight chart13

The biggest difficulties13 for growing13 out razorback suckers13 at the13 24-shy‐Road13 Fish13 Hatchery13 are13

insufficient space and water flow (oxygen) to grow fish to the target size At the Horsethief

15

13

Basin13 Ponds where broodstock13 are reared13 diseases such as Ich are problematic because

water is pumped directly from13 the Colorado River

Ouray13 National Fish Hatchery13

Ouray13 National13 Fish Hatchery maintains its own broodstock and13 spawns13 fish on-shy‐site13

Larvae are transferred from13 indoor hatching tanks to unfertilized 02 acre outdoor ponds

and stocked at densities 10000 ndash 20000 larvae13 per13 pond13 Even13 though13 outdoor13 ponds13 are13

covered with13 bird13 netting13 avian predators13 still get caught in the13 nets13 if they13 can see fish

Ponds are dyed blue13 as the13 fish grow to13 prevent avian predation13 While in the outdoor

ponds13 fish13 are13 fed a slow-shy‐sinking salmon diet made by Silvercupreg twice daily by hand

Amount of feed is based on periodic sample counts Fish are grown until late September at

which time temperatures require that all fish13 other13 than13 adult broodstock13 be13 brought

inside for the winter Ponds are drained completely and fish are sorted by hand Fish that

have reached the target size (300 mm TL) are stocked into the Green and Colorado Rivers

All remaining fish are moved indoors13 and13 held13 in three-shy‐foot (n= 30) or eight-shy‐foot (n=27)

diameter circular tanks On average it takes 12 ndash 18 months to grow fish to the 300 mm TL

at Ouray13 hatchery13

Razorback suckers are held during the winter in a recirculating system13 that

operates13 using13 two13 large13 fluidized-shy‐bed sand filters and a rotating-shy‐drum13 filter for solids

removal Fish are fed the Silvercupreg razorback diet using belt feeders There is currently

capacity13 to13 hold13 only13 20000 200-shy‐300 mm TL fish inside the facility and any extra fish13 are13

stocked13 into13 floodplain-shy‐wetlands or used for research purposes13 Ouray no longer leases

any private grow-shy‐out ponds Grow-shy‐out ponds were troublesome due to poor water quality

harvesting13 difficulties13 and13 non-shy‐native13 fish introductions13 The biggest difficulty13 for

production13 of razorback13 suckers at the Ouray13 National13 Fish13 Hatchery13 is space13 during13 the

winter to maintain large numbers of fish and high iron and manganese in the well water

that must be filtered out prior to use

16

13

Willow Beach National Fish Hatchery13

Willow13 Beach National13 Fish Hatchery receives wild-shy‐caught larvae from13 Lake

Mohave Larvae are treated for diseases with formalin and malachite green and placed in

45 ten-shy‐gallon13 flow-shy‐through aquaria13 Recirculated13 solar heated water13 22-shy‐25deg C is used to13

allow production of warm13 water fish at this traditionally cold water facility (Figiel 2003

Figiel et al 2005) Fish are fed brine shrimp nauplii to satiation every hour and after 14

days small amounts of specialized larval fish diet (Encapsulon13 Cyclopeeze13 spirulina13 and

artificial plankton) are introduced After 30-shy‐6013 days13 fish are13 transferred13 to13 six13 32-shy‐gallon13

fiberglass troughs at densities of 1000 to 1500 fish per tank and then a month later moved

outside13 to13 eight recirculating13 raceways that use a combination of well water and solar-shy‐

heated water to maintain temperatures of 22 ndash 25deg C during the summer months

When13 in13 the outside raceways13 fish are fed the razorback13 diet13 using13 belt13 feeders and

fed by13 hand13 at 10 -shy‐ 70 body13 weight per13 day Feed amount is adjusted based on sample

counts according to a feed conversion program13 developed for razorback suckers by Willow

Beach Hatchery personnel This program13 uses length and number-shy‐per-shy‐pound generated

from13 several years of razorback growth data (Figure13 1) Fish are13 sorted13 opportunistically13

and are not handled during the summer months when water temperatures are above 20degC

In 2004 the target size for stocking was 325 mm TL or greater (WBNFH 2004) with a

target13 of producing13 6000 fish per year Reaching this13 target size usually13 takes13 two13 growing13

seasons13 The biggest difficulty13 in rearing13 razorback suckers13 at Willow Beach13 National Fish

Hatchery13 is insufficient space13 to13 grow fish to13 increased13 target sizes (400-shy‐500 mm TL)

Uvalde13 National Fish Hatchery13

Uvalde13 National Fish Hatchery13 in Texas13 receives 35000 ndash 60000 razorback sucker13

fry annually in MarchApril from13 Dexter National Fish Hatchery The fry are acclimated in

bags submerged in the pond for a minimum13 of one hour and released into13 a 1 acre13 fertilized13

pond where they are reared for the remainder of the summer Fingerlings are fed a starter

razorback diet when they reach approximately 50 mm TL In AprilMay the previous year

class of razorbacks are captured from13 their over-shy‐wintering pond enumerated graded and

split into13 one-shy‐acre grow-shy‐out ponds Approximately 4000 ndash 5000 fish will be13 placed13 in each13

one acre pond for summer grow-shy‐out Fish are reared for approximately 150 days (May ndash

17

13

Oct) and fed the Bozeman razorback diet two times a day five days a week at 15 ndash 30

body weight per day based on average water temperature

Figure 1 Relationship between length and number of fish per pound

In general13 juvenile razorback13 suckers (received as fry13 during13 the previous spring)13

reach the target size of 300 mm TL in approximately 6 months In 20062007 Uvalde

produced 6000 razorback suckers 300 mm TL for introduction into the San Juan River

Starting13 in 2008 Uvalde NFH will be producing13 and distributing13 12000-shy‐ 300 mm TL

razorbacks for stocking into the San Juan River Predation from13 migrating cormorants has

occurred but timing of harvest and over wintering protection methods such as covering

ponds with netting or placing fish indoors helps to minimize losses during the cormorant

migration (November to March) Uvalde has experienced razorback mortalities because of

bacterial problems but these are usually resolved through the use of oxytetracyline

medicated feed

Overview13 of Differences in Culture Methods

Several differences were noted when conducting surveys at each of the five main

production facilities for razorback sucker (See Appendix 3) These differences include

different stocking13 and13 rearing13 densities13 (Table13 4-shy‐5) various feeding regimes and type of

18

13

lt=amp

feeds (Table 7) as well as differences in grading or sorting practices Some of these

differences are13 related13 to13 whether13 or not razorback suckers13 are13 being13 reared13 in extensive-shy‐

culture13 facilities13 (ponds) or intensive-shy‐culture13 settings13 (raceways13 o tanks)13 Some13 practices13

are unique to a single facility13 or a couple of facilities (Table 6)13 Managers at each facility13

were asked to identify the biggest13 difficulty or constraint13 that13 they experience when13

growing-shy‐out juvenile13 razorback suckers13 at their13 respective13 location13 Space constraints13

water quality and disease problems were the main factors limiting production of razorback

suckers13 at these13 facilities13 (Table13 8) Calculated or reported growth rates from13 the literature

vary widely (Table 9) and range from13 02 to 18 mmday These growth rates indicate that

juvenile razorback suckers have a very high growth potential under optimal rearing

conditions13

Table13 4 Stocking13 densities13 for larvae13 and13 fry in ponds

$amp( )(+amp-( 01-2(3(4amp56( 4amp56(+amp-( 01-2782-( $amp () + --amp +amp0amp)+amp 12-3amp ( )+amp0amp+amp --amp +amp0amp)+amp 42556789amp8 ( +amp0ampgt+amp 3amp +amp0amp+amp A-BC-Damp (E + 3amp )+ F-6ltamp ) G+ 3amp G+

Table13 5 Rearing13 densities13 at intensive13 culture13 facilities13

$amp( )amp+(($-( $0( 12(3$+( 40((amp05( 67((amp05( 8$9(407$( $amp amp())amp++-$amp 0 1 0amp2amp1amp 3amp2amp4 0544

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19

13

Table13 6 Rearing13 practices13 that are13 unique to13 specific rearing13 facilities13 $$amp( )$+-(amp$-(0(1-amp2034( $amp()amp+( -0$(12(33+(amp(amp134$53+(amp$amp3+(6amp+(

723(843(1$8(422(6amp+(42amp(4(423(19$43( 343( lt34$53(6amp+(6(4($03(amp4+94amp(842($1$1(63$$34(amp+(63626243( =amp+(gtamp94ampA( B3(1(1$+53+C3+(amp+(1$43(1(3D0$(1(amp443(amp+(amp443( 734231(amp( B3(1(193(44(1(34amp(amp(+49E(6amp+( -E3(F3+( G3amp(1(12(amp(H3(13$(4ampE(C(IJK($$amp( A( L43(+A3(4(6303amp4(63+4ampM(66$3D3amp4$(34amp(amp(6amp+(C((4amp3( L$$8(392(

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Table13 7 Types of feed used at razorback sucker13 hatcheries13 $amp ()amp+-amp0- $$)1amp23 45-amp)-$5)1amp23 $amp()amp+( -amp$amp+(amp+( -amp012$3+(amp+4(amp5215$(0+( 65ampamp7(85209(+2($1(87((15315lt=(+2(

+amp+amp(amp(55$5$2gt( 21( Aamp+(amp+( )amp+(012$3+(B29(5$05$95($$2(5amp+(

199524(amp5215$(0+( 65ampamp7(85209(+2($1(87(15315lt=(+2(amplt( 29gt(51($51(amp9(2(25=(C(DD(0+(

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$1(87(15315lt=(+2(D5$$(3(lt5$$gt(02+(gt( 6lt=(511B(

L15gt( G1$5(lt1lt$51(25amp=(Aamp+( amp+(

HIJKH(Dlt1amp(15315lt=(+2(I(C2(CH(+5gt( )11$gt($511(02+(15315lt=(+2(

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M$$B(5lt9(-5$+( NO515(G1$5(219( L2+1(15ltB5gt(Aamp+(5amp+( amp$amp+(amp+(

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$1(87(15315lt=(+2($1(87(15315lt=(+2( $1(87(15315lt=(+2(

Table 8 Factors limiting production at major razorback sucker facilities

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Table9Reportedandcalculatedgrowthratesfromtheliterature

Calculatedgrow

thratesbasedon

informationprovidedinliterature

aApproximationsofmaximum

grow

thpotential(basedon

average13 maximum

sizesiffishreportedatharvest

21

13

General Information on Factors that Affect Fish Growth

Growth in fish is extremely variable and is impacted by many different

physiological and environmental factors Growth rates are known to change with size and

age sex season activity level density amount13 of living space quality and quantity of food

genetics and temperature (Brett 1979) Growth experiments conducted at different times

of year can result in growth rates that are not comparable As fish become larger their

physiological13 potential to grow decreases making determination of growth rate dependent

on the size of the starting fish and the length of the experiment (Busacker et al 1990)

Genetic factors also have great potential to influence growth rate Some species have

strains13 and13 races13 that display vastly different growth potentials (Reinitz et al 1979) All of

these factors combine to make assessment of the individual factors controlling fish growth

difficult13

Water temperature is probably the most important variable affecting growth rate13

All of the basic functions that affect growth such as feeding digestion and metabolism are

temperature-shy‐dependent13 Growth13 is inseparably13 tied13 to13 bioenergetics13 and13 therefore13 also13

tightly tied to temperature When temperatures are below optimum daily temperature

fluctuations can stimulate growth Photoperiod is also commonly linked to water

temperature and can influence growth rates in fish (reviewed in Brett 1979)

Fish density13 is known to13 affect growth13 and13 can alter13 growth13 rates13 in several ways13

Fish that exhibit strong territorial behaviors13 or natural schooling tendencies13 will

experience reduced growth if densities are too high or too low (Brett 1979) Dominance

hierarchies where some fish feed more aggressively than others can also lead to high

variability13 in growth13 rates13 (Koebele13 1985) Crowded13 conditions13 also13 cause physical

interference13 between13 fish and13 poor water13 quality13 which13 reduces13 growth13 (Busacker13 et al13

1990) The effects of fish numbers space and feeding opportunity are frequently correlated13

and often13 difficult13 to distinguish (Brett13 1979)13

It is impossible to study the effects of environmental factors on growth without also

evaluating feed rations (Brett 1979) Amount of food quality of the diet particle size

number of feedings per day and time of feeding have all been shown to affect growth

(Busacker et al 1990) In controlled laboratory studies food is usually fed ad libitum13

22

13

(constantly available) and other variables are altered to assess impacts of environmental

factors13 on growth13 These studies13 are13 usually13 conducted13 in tanks13 or raceways13 because13

researchers must verify that food is constantly available to the fish which is difficult to do

in large pond environments where the fish and the bottom13 are often not visible (Busacker13

et al13 1990)

Specific Information13 o Razorback13 Sucker13 Growth

Variable13 growth

Growth in razorback suckers is naturally highly variable and may be a function of

their evolutionary history (USFWS13 2002)13 Minckley (1983) speculated that13 wide size

variation in a single cohort of razorback suckers may be adaptive with fast-shy‐growing13 fish

that13 reproduce at a young13 age surviving13 better in13 high discharge years and slow-shy‐growing13

smaller fish surviving better during drought periods This highly variable growth rate

makes rearing razorback suckers in a production setting difficult because fish from13 a single

cohort do not reach the target stocking size simultaneously One of the major tasks for

aquaculture is to maximize both individual growth and total production13 (Gerking13 1978)13

This becomes more difficult when the species being cultured exhibits highly variable

growth13 rates13 because of genetic influences as is the case with razorback13 suckers13

Razorback13 sucker growth13 is typically very13 rapid13 during13 the first13 year of life13 and then13

declines with age First year growth can be as low as 50 mm and as high as 350 mm (Valdez

et al13 1982 Minckley13 1983 Mueller13 1995) Razorback sucker13 grow rapidly13 for

approximately the first five or six years of life and then growth slows13 (McCarthy13 and13

Minckely 198713 Tyus 199813 Minckley et13 al 1991)13 Growth of older individuals in13 extant13 wild

populations is very13 low (Minckley 198313 Tyus 198813 Modde13 et al 1996)13 Wild growth13 rates

for mature adult fish in Lake Mohave based on PIT tag recaptures were often too small to

be accurately measured for both males and females over the time period of 1987-shy‐199713

(Marsh and Pacey 1998) This information suggest it will take substantially longer to rear

fish to13 increasingly13 larger13 stocking13 sizes (40013 ndash 500 mm TL) than it did to reach the target

size of 300 mm TL

Growth in ponds

23

13

One of the main strategies for maintaining genetic refugia and self-shy‐sustaining13

populations of razorback13 sucker in the lower Colorado13 River basin13 is to rear razorback13

sucker13 larvae13 in production13 ponds until they13 are13 a suitable13 size for stocking13 (USFWS13 2004)

Pond culture has proven useful to promote rapid growth of juvenile razorback suckers

(Kaeding and Osmundson 1989) Marsh (1994) reported that growth rates of razorback

suckers13 reared13 in golf-shy‐course13 ponds exceeded13 the13 best growth13 rates13 obtained13 under

intensive13 culture13 conditions13 at federal hatcheries13 especially13 during the13 first several years13

of life Growth rates in these semi-shy‐natural ponds are also comparable to estimated growth

rates13 of juvenile13 wild13 fish (McCarthy13 and13 Minckley13 1987) Modde13 and13 Haines13 (2005)

reported13 the13 greatest growth13 rates13 in the13 largest and13 deepest floodplains13 with13 the13 greatest

amount of submergent vegetation but excellent growth and survival of fish in a grow-shy‐out

pond is of little value if there is not an efficient way to collect the fish from13 the pond

(Kaeding and Osmundson 1989)

Temperature13

Bulkley and Pimentel (1983) used shuttle boxes in the laboratory to determine a

temperature preference13 for razorback suckers13 of 23-shy‐24degC13 In13 their13 studies13 razorback

suckers were found to avoid temperatures below 118 degC or above 286 degC Razorback

suckers at Bubbling Ponds Hatchery are more active in the spring and feed better as

photoperiod increases even prior to water temperatures rising (Frank Agygos personal

communication) Table 3 briefly summarizes water temperature data from13 each facility

Detailed seasonal water temperature profiles are not currently available for many

razorback grow-shy‐out sites13

Density13

Extensive studies have been conducted on commercially important species to

evaluate stocking densities and feeding rates that maximize production For these species

controlled experiments under laboratory conditions have established relationships

between temperature density and feed ration on growth (Brett 1979) but this information

is sporadic13 or non-shy‐existent for razorback suckers13 (Bays13 et al13 2005) Fish culturists13 with13

24

13

experience13 rearing13 razorback suckers13 typically13 have13 target stocking13 densities13 that13 they use

(Tables13 4 -shy‐ 5) These stocking densities have largely been determined over time by trial

and error These approximate stocking densities provide a good starting point for more

controlled13 types13 of replicated13 pond studies13

Feed ration

Razorback13 suckers are currently13 being13 fed a wide variety13 of prepared diets (Table 7)

that range from13 a slow-shy‐sinking salmon feed manufactured by Silver Cupreg to a spirulina

and krill-shy‐enhanced catfish feed made by Rangenreg Most locations are feeding 20 ndash 50

body13 weight per13 day13 Methods13 for culture13 of razorback sucker13 larvae13 in intensive13 settings13 at

fish hatcheries are well documented (Figiel 2005) and various larval fish diets have been

evaluated13 (Tyus and13 Severson 1990 Severson et al13 1992) but no standardized13 procedures

are used for feeding13 larval13 fish in13 intensive settings13

Razorback sucker larvae are also effectively reared in pond environments using

natural foods supplemented with larval fish diets and survival is high when no predators

are present13 (Mueller 2006)13 Growth rates for larval13 and early juvenile razorback13 suckers

may increase with pond fertilization Diet and physiological studies on wild razorback

suckers indicate that they feed on plankton as well as benthic organisms during their entire

life (Marsh 1987) Artificially fertilizing ponds may greatly increase production capacity

and growth rates for razorback13 sucker (Papoulias and Minckley13 1992) and warrants

further13 investigation13

Handling stress

Handling stress13 has13 been shown to13 influence growth13 rates13 Paukert13 et al (2005)

found that growth of bonytail chub was reduced by 26when compared with controls

after being13 repeatedly13 captured and handled in13 hoop13 nets13 Handling13 effects are likely13 to be

similar for razorback suckers that are repeatedly13 captured and sorted in13 a hatchery13 setting13

Razorback suckers that are handled at Willow Beach National Fish Hatchery will commonly

not eat for two weeks after handling (John Scott personal communication) This creates a

difficult situation13 for production13 facilities because13 fish13 need to be sorted to ensure13 large13

25

13

aggressive fish do not interfere with growth of smaller individuals but frequent handling

and sorting13 causes stress related reductions in13 growth13

Measuring Growth in Captive Fish

Weight is the traditional measure used to estimate growth or production in

aquaculture settings13 Groups of fish are typically13 weighed and an average individual13 weight13

is computed (Busacker et al 1990) Although this method is often logistically the easiest it

may not be the most informative for species with highly variable growth rates like

razorback suckers especially when target lengths must be reached before fish can be

stocked Weight can also be highly influenced by things like stomach fullness or

development of gonads (Busacker et al 1990) Condition factor or relative weight can also

be used to assess growth of fish but these tools may be more robust predictors of fecundity

than of growth (Anderson and Neuman 1996) For some species sexes need to be

distinguished because males and females may differ in morphology (Anderson and

Neumann 1996) Mueller (2006) analyzed growth rates based on PIT tag recaptures of 86

razorback suckers13 in High13 Levee Pond13 and13 found13 that differences13 in growth13 do not appear13

to occur until fish are over 450 mm TL at which time growth rate in males slows while

females continue to grow at a slightly higher rate This would indicate that sex may not be

an important factor to consider when examining growth rates unless the target grow-shy‐out

size is above 450 mm TL

The best measures of growth are often determined from13 the length and weight of

individuals rather than from13 groups of fish (Anderson and Nuemannn 1996) because

individual growth rates give better estimates of confidence and variance (Busacker et13 al

1990) Length frequency analysis or recapture of previously marked individuals of a known

size is likely to yield the most useful information for razorback sucker growth The success

of any of these methods depends on proper sampling procedures that are representative of

the population as a whole (Busacker et al 1990) Sampling methods that are known to be

size-shy‐biased such as trammel nets (Mueller et al 2004) or cast nets should not be used when

trying to measure growth rates13

26

13

Conclusions

For razorback sucker survival is largely associated with stocking size Additional

focused13 research13 is therefore13 needed to13 identify13 ways13 to13 increase13 growth13 rates13 of captive-shy‐

reared13 razorback sucker Growth13 rate13 in fish is controlled13 by many factors including fish

size and age temperature density and feed ration which can all be highly correlated

Growth of razorback suckers is also inherently variable which makes the task of identifying

the key factors that13 affect13 growth in13 captivity even more difficult The focus at most

razorback rearing facilities13 is production so the13 types13 of data that are13 collected13 are13 often

insufficient for detailed13 evaluations13 of individual rearing13 practices13 on growth13 Surveys of

existing13 razorback sucker13 rearing facilities indicate that culture methods vary widely and

the types of growth data13 that13 are collected are not13 standardized13 Replicated studies with

detailed information on rearing location water temperature initial stocking size stocking

density and the sizes of all fish at harvest are needed in order to compare the effects of

individual rearing practices on growth This type of research will ultimately provide both

time and cost-shy‐savings to production facilities by reducing the amount of time necessary13 for

razorback sucker to reach stocking size improving overall production efficiency

Optimum13 rearing densities for razorback sucker larvae and juveniles remain to be

determined Current stocking densities will be very useful as starting point for more

detailed studies and although optimum13 rearing densities are likely to be site-shy‐specific13

replicated studies on density will provide a valuable reference for hatchery managers

Frequency13 of sorting is another13 area that needs13 further13 research Frequent

handling13 and13 sorting13 can13 cause13 stress-shy‐related13 reductions13 in growth but not sorting can

create dominance hierarchies that further reduce growth rates of subordinate individuals

The effects13 of sorting13 on overall fish growth13 in both13 pond and13 intensive13 culture13

environments warrant further investigation Research techniques for these types of

experiments are well understood and typically utilize a matrix of replicate ponds per

variable (Bays et al 2005) In every case accurate and complete records of sampling

procedures and data collection are needed in order to interpret data and make inferences

about13 growth rates (Busacker et13 al 1990)13

27

13

Additional research is also needed to evaluate long-shy‐term13 survival of stocked fish

reared in ponds compared to fish13 reared13 in intensive13 culture13 facilities13 Exercise13

conditioning13 and predator-shy‐recognition training may also increase survival of stocked fish

and be more economically feasible than rearing fish to increasingly larger sizes prior to

stocking13 The success13 of traditional fish hatchery programs is measured largely by the

number of fish stocked but hatchery programs for endangered species must measure

success in terms of long-shy‐term13 survival and species recovery (Brannon 1993 Anders 1998)

A specific list of research recommendations follows

Specific Research13 Recommendations13

bull Use replicated studies13 to establish optimum stocking13 densities13 for ponds13 and

tanks13 that can be used as13 a starting13 point for site specific refinement

bull Determine if sortinggrading13 improves13 overall growth rates13 in both ponds13 and

intensive culture facilities13

bull Investigate the use of artificial fertilizers13 to improve growth of both juvenile

and adult razorback suckers13 in ponds13

bull Determine if the razorback sucker diet gives13 better growth rates13 than cheaper

catfish or salmon feeds

bull Evaluate growth rates13 and production potential of new intensive culture

methods13 such as13 large circular tanks13

bull Evaluate13 long-shy‐term survival of fish produced from raceways13 and circular tanks13

compared to fish reared in ponds13

bull Evaluate more effective means13 of treating13 fish diseases13

bull Evaluate factors13 other than size that may increase post-shy‐stocking13 survival such

as13 exercise conditioning13 predator recognition training or rearing13 under more

natural settings13

28

13

II The Effect of Disease Treatments on Razorback Sucker

Growth

Section13 SummaryFormalin copper sulfate potassium permanganate and13 salt are all chemicals commonly13 used13 to13 treat13 Ichthyophthirius multifiliis outbreaks in captive razorback sucker (Xyrauchen13 texanus) Weexposed 190 juvenile13 razorback suckers (127 ndash 26 mm TL) to13 5 5-shy‐day treatments with13 each13 chemical to evaluate the effects13 these chemicals13 may have on growth Fish grew an average of23513 mm TL13 during the month13 study period Fish treated with formalin grew on average13 29mm TL (03 mmday) while fish treated with copper had the lowest growth averaging 20 mmTL (021 mmday) No significant differences in13 growth were observed among fish treatedwith any of the chemicals compared to untreated fish (pgt005) Reductions in growth13 as aresult of repeated chemical treatments are not likely the cause of differences in growth ratesamong13 facilities that raise razorback suckers Repeated chemical treatments may13 have otherimpacts to overall13 fitness or long-shy‐term survival but13 these effects were not13 evident13 in our study

29

13

Introduction

Preservation13 of razorback sucker13 (Xyrauchen texanus) currently13 depends on captive13

rearing and stocking programs until permanent solutions to factors that prevent wild13

recruitment are found Low survival of stocked razorback suckers (Brooks 1986 Marsh

and Brooks 198913 Marsh and Pacey13 2005) has caused target13 sizes for stocked fish to

steadily increase in efforts to reduce predation mortality (Marsh et al 2005 Schooley and

Marsh 2007) Rearing fish to larger sizes at hatcheries comes with increased costs and

creates the need to evaluate husbandry and rearing practices that may affect fish growth

Formalin copper sulfate potassium13 permanganate and salt are all chemicals

commonly used at razorback sucker rearing facilities to treat outbreaks of the protozoan

parasite13 Ichthyophthirius multifiliis ldquoIchrdquo is one of the most pathenogenic diseases of

cultured13 freshwater13 fishes (Matthews13 2005) and causes large13 losses in captive13 populations13

of endangered razorback sucker Each of these chemicals used to treat Ich only kill the free-shy‐

swimming life stage of the parasite13 requiring13 repeated doses over several13 days depending13

on water temperature These chemicals treatments are needed to prevent loss as a result

of disease outbreaks but the cumulative effects repeated disease treatments have on

growth13 are13 unknown

Copper13 sulfate13 has13 been shown to13 significantly13 reduce13 growth13 of channel catfish13 in

production13 ponds (Rabago-shy‐Castro13 2006) but it is unknown whether13 razorback suckers13

experience similar reduced growth following copper treatment Quantifying the impacts of

disease treatments on growth will help to interpret the wide differences in growth rates

observed13 at various13 razorback sucker13 production13 facilities13 throughout the13 southwest

(Ward et al 2007) If one chemical is found to have less detrimental impacts on growth

than another then it may be preferred for use as a disease treatment We evaluated growth

rates13 of razorback suckers13 under13 replicated13 and13 controlled13 conditions13 to13 assess13 effects13 of

repeated formalin copper sulfate and potassium permanganate and salt treatments on

growth13

Methods

We captured 190 juvenile razorback suckers from13 ponds at Bubbling Ponds Fish

Hatchery AZ using hoop nets or cast nets All fish were of the same age class and

30

13

averaged 179 mm total length (TL) (range13 = 127 ndash 262 mm TL)13 These fish were13 offspring13

of captive13 razorback sucker13 broodstock held13 at Dexter13 National13 Fish Hatchery13 NM13 (2007

year class) All fish were tagged with passive integrated transponder (PIT) tags and

quarantined for one month prior to the experiment to allow fish to recover from13 tagging

and become accustomed to being held in circular tanks

At the beginning of the study all fish were weighed measured and scanned for

individual tag numbers with 19 randomly selected fish placed into each13 of 10 8-shy‐foot

diameter circular tanks (Figure 2)13 Each13 tank contained13 two13 airstones13 and13 an13 individual

biofilter with a recirculating water pump (31 litersminute) that had been operating for

at least 1 month prior to the experiment to allow bacterial colonies to become

established Two tanks were designated as a control and did not receive any chemical

treatments while the other eight tanks received formalin copper sulfate potassium13

permanganate or salt treatments at two week intervals (two tanks per chemical

treatment) Formalin copper sulfate and potassium13 permanganate were treated at 1 part

per million (ppm) and salt was applied at 30 parts per thousand (ppt) These treatment

rates are commonly used to treat13 razorback13 suckers for ich at Bubbling13 Ponds Fish13

hatchery (Frank Agygos personal communication)

Figure 213 Photo ofexperimental tankswith individualbiofilters and aeration

31

13

Each treatment consisted of a series of doses applied on Wednesday Thursday and

Friday with a 90water change between each dose Biofilters were removed from13 all

tanks and held in a separate holding facility during treatments and then replaced on the

Monday following treatments after a 90water change This schedule allowed fish to be

exposed to chemical treatments for 5 consecutive days without water quality deteriorating

This 5-shy‐day chemical treatment was repeated every two weeks from13 July to October (97

days)13 for a total of 5 5-shy‐day treatments Water temperature in the treatment tanks ranged

from13 13degC (55degF) to 32degC (91degF)

Fish were fed a fixed ration of commercial razorback diet (Silvercup 4mm13 pellet)

once daily13 (2 percent body13 weight per day13 as calculated13 by13 average initial fish weight)13

At the end of the experiment all fish were again weighed measured and scanned for

individual tag numbers Growth of fish in each treatment group was compared using

analysis of variance (ANOVA) Any mortalities13 that occurred during the13 study13 were13

replaced with previously quarantined fish of equivalent size to maintain equal densities in

each13 tank13 but growth13 data was13 only13 recorded for fish which13 survived13 the13 entire13

experiment

Results

Fish at the13 start of the experiment averaged 179 mm TL (Range13 = 127 ndash 262 mm)

with no significant differences in fish length among treatment groups (F(4189) = 00183 p

gt 0999 ANOVA) On average fish grew 235 mm TL (024 mmday) during the 3 month

study13 Fish in tanks13 treated with formalin had the highest growth averaging 29 mm TL (03

mmday) while fish in tanks treated with copper had the lowest growth averaging 20 mm

TL (021 mmday) Fish in the control tanks averaged 213 mm TL in growth (022

mmday) (Figure13 3)13 Formalin-shy‐treated fish grew13 significantly faster than13 any other

treatment group but no13 significant differences in growth13 in length13 or weight were13

observed among fish treated with any of the chemicals compared to untreated (control)

fish (pgt005 ANOVA)

32

13

Figure 313 Average growthof razorback suckersexposed to a series of 5 5-shy‐day chemical treatmentsover a 97-shy‐day13 periodError bars representstandard error

Discussion13

Growth13 rates13 observed13 in our study13 (021 ndash 03 mmday) are low compared to those

reported13 in other13 studies13 of razorback sucker13 growth13 (0213 ndash 18 mmday) (Ward et al

2007) Using recirculating water systems for our study required filters to be removed and

replaced during treatments Stress to fish caused by removing and replacing filters within

the tanks as well as repeated water changes may have led to overall higher stress and

reduced growth rates compared to those reported for unconfined fish Growth in fish is

highly variable and is affected by many different physiological and environmental factors

including fish size density temperature amount of space and food (Brett 1979) We

strived to control each of these factors but other factors may have also influenced growth

in our experimental tanks During mid-shy‐summer water temperatures in the treatment

tanks reached 32degC (91degF) At these warm13 temperatures fish are very susceptible to

bacterial13 infections13 The slightly higher growth exhibited by fish in the formalin and

potassium13 permanganate treatments may have been the result of these two chemicals

33

13

being effective at controlling bacterial infections The differences in growth we measured

among treatment groups were not statistically significant and do not appear13 biologically13

meaningful during the relatively short duration of this study (97 days) although the

cumulative effects of slightly reduced growth could be biologically meaningful over longer

time frames

Reductions in growth13 as a result13 o repeated chemical treatments are not likely the

cause of differences in growth rates among facilities that raise razorback suckers

Repeated chemical treatments may have other impacts to overall fitness or long-shy‐term13

survival but these13 effects13 were13 not evident in our study It is more likely that the parasite

outbreaks themselves are the cause of different growth rates among razorback rearing

facilities rather than the chemical treatments used to treat the parasites We recommend

that hatchery managers continue to use the chemicals that are most effective at controlling

ldquoIchrdquo13 at their individual13 facilities

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower Colorado Rive Multi-shy‐species13

Conservation Plan under Work Task C10 We thank Ty Wolters and Tom13 Burke for their

support of this research and Frank Agygos and Dave Billingsly of the Bubbling Ponds Fish

Hatchery13 for their13 technical assistance13 and13 help with13 collecting13 fish

34

13

III13 Razorback Growth Rates at Bubbling Ponds ndash 2009-shy‐2011

Section13 SummaryExperimental studies at Bubbling Ponds Fish Hatchery AZ have strived to understand

factors that affect razorback sucker growth in captivity and identify ways to improve growthrates and maximize size at release Rather than performing experimental studies that wouldrequire major13 rearrangement (and likely reduced production)13 of hatchery operations our13 studies13 used normal variation in production techniques13 and practices13 to isolate factors13 thatmay modify growth rates

Our initial work identified razorback13 growth rates in13 lined ponds at standard fishdensity as 026 to13 028mmday (789 to 843 mmmonth) No significant differences in growthrate were observed among fish that had been in the pond only during the winter13 periodcompared to fish that had been in the pond the entire year indicating that water temperatures13 at Bubbling Ponds are high enough to allow fish to incorporate feed effectively year-shy‐roundHowever these growth rates are lower than most values reported from the literature fromnatural or semi-shy‐natural pond environments No significant differences in13 growth rate wereobserved13 between large and13 small fish13 within the 150 ndash 29 mm TL13 size range Additional worksuggests13 that razorback suckers13 tagged at over 300 mm TL had reduced growth rates (024mmday 73 mmmonth) as would be expected according to a typical Von13 Bertalanfy growthcurve although growth rates13 were only slightly less13 than the average growth rate for thehatchery (027513 mmday 82513 mmmonth)

Sorting13 to13 separate small fish from large fish after the first year of growth is practicedesigned13 to allow smaller fish to ldquocatch uprdquo to larger fish We found that13 this technique doesappear to13 improve growth rates of smaller fish Growth rates of sorted small razorback suckers(029 mmday 87mmmonth)13 were equal to that13 of larger13 fish (028 mmday 8413 mmmonth)indicating that sorting may have helped to offset their original slower growth trajectory

Bubbling Ponds Fish Hatchery grows razorbacks in 6 long deep ponds lined with heavyplastic 2 long deep13 earthen13 (unlined) ponds and three wide shallow earthen ponds The wideshallow ponds13 have historically produced very large fish at low density but have been found tomaintain much lower fish numbers than deeper ponds We found13 that growth13 rates ofrazorbacks kept at high density (4-shy‐700013 fish)13 in a wide shallow pond grew extremely slowly(024 mmday 726 mmmonth) This growth rate is among the slowest of any fish over theyears of our study and demonstrates that13 though the large ponds may produce large fish at lowdensity13 they are unable to overcome high13 fish13 densities

Finally one of the major factors influencing13 fish13 growth13 in hatcheries is disease onemajor summer-shy‐time disease at13 Bubbling Ponds is the ectoparasite Ich (Ichthiopthirusmultifiliis) To investigate the impact Ich has on razorback growth we eradicated fish from thespring and water conveyance ditch that supplies13 water to the hatchery using Rotenone This13 restoration effort was fairly short-shy‐lived (Ich returned to the hatchery within four months) but

35

13

growth13 rates of fish13 reared for four months without Ich present (031 mmday 92 mmmonth)were significantly higher than the following 8 months of growth for those same fish (022mmday 65 mmmonth) This disease-shy‐free growth rate is in fact faster than any13 otherprevious growth rates observed at the hatchery in our study

We conclude that growth rates at the Bubbling Ponds Fish Hatchery are likely as highas possible given the pond densities required to13 meet production goals and the Ich-shy‐infestedwater13 that feeds the facility Sorting practices are successful in helping as many fish as possiblereach stocking length as fast as possible Unlined ponds may be able to grow large fish at lowdensities but whatever factors allow for that growth13 are not able13 to overcome13 high fish densityThus the large lower ponds at Bubbling Ponds may be better utilized via renovation to13 deepenand line them

Disease is the most important factor limiting growth as may be expected to be the caseat many13 hatcheries While the spring renovation was not13 a complete success13 the dramaticreduction of fish populations in that habitat was enough to dramatically13 reduce13 the13 occurrenceof Ich at the hatchery13 Such open spring13 systems feeding a hatchery are a misfortune that canbe expected to transmit disease so we suggest that renovating the spring again to combat13 IchImproved techniques to divert water from13 the springs and more throuough treatment ofstream-shy‐side vegetation may improve the success of chemical treatment Successful renovationwould likely both improve growth rates and reduce chemical costs associated with treating Ichoutbreaks Even13 if complete renovation13 is impossible or impractical an13 effort to reduceinvasive fish density in the springs13 which act a vector for the parasite(and thereby reduce thelikelihood of13 Ich being transmitted into ponds) may still13 show dramatic improvements

36

13

Introduction

Conservation efforts13 for razorback sucker13 (Xyrauchen texanus)13 currently13 depend on

captive rearing and stocking programs Low survival of stocked razorback suckers (Brooks

1986 Marsh13 and13 Brooks13 1989 Marsh13 and13 Pacey13 2005) has13 caused13 target sizes for stocked13

fish to steadily increase in efforts to reduce predation mortality13 (Marsh13 et al13 2005

Schooley and Marsh 2007) Rearing fish to larger sizes at hatcheries comes with increased

costs and creates the need to evaluate husbandry and rearing practices that may affect fish

growth13 We evaluated growth13 rates13 of individual razorback suckers13 in ponds13 at Bubbling

Ponds Fish Hatchery13 using Passive Integrated13 Transponder (PIT) tags13 to13 obtain13 precise

growth information for individual fish so that valid comparisons of growth rates as related

to rearing practices can be made

Due to the critical nature of the razorback sucker stocking program we did not

design experimental studies that would require major rearrangement and potentially

reduce production of hatchery operations Instead our studies used normal variation in

production techniques and practices to isolate factors that may modify growth rates

Though this methodology dramatically limits replication and may limit our ability to

directly13 attribute13 differences in growth13 rates13 to13 the13 variables13 we13 investigate13 we13 were13 able13

to accomplish research goals without altering hatchery operations or impacting

production

From13 2009 through 2011 we conducted a series of observational13 growth13 studies to

determine growth rates of individual razorbacks at Bubbling Ponds The first set of

experiments included13 identifying13 growth13 rates13 in lined13 and13 unlined13 ponds determining

growth13 rates13 of fish at different13 sizes13 in13 relation13 to sorting13 practices and monitoring

razorback growth rates after removing the source of the ectoparasite13 Ich (Ichthiopthirus

multifiliis) from13 the hatchery water source13

Razorback growth rate in lined ponds

Our first growth study documented individual growth rates at normal density in 11

million gallon lined ponds13 over two13 years13 This is the standard13 grow-shy‐out process for

razorbacks13 at Bubbling Ponds We monitored growth of fish for a variety13 of sizes and13 the13

37

13

amount of time in a pond during the growing season These13 data give a snapshot of growth13

rates13 at the13 facility13 and13 provide13 the basis for comparisons throughout our study

Growth rate13 in an unlined pond

In addition13 to 6 ponds lined with heavy plastic13 sheeting13 Bubbling Ponds Fish13

Hatchery maintains two narrow and deep (same dimensions as lined ponds13 Figure13 4)13 and13

three large13 shallow unlined ponds These earthen13 ponds typically have vegetation and

associated aquatic invertebrates that may better simulate natural environments by

providing cover and improved food diversity or quality Therefore these unlined ponds

may be expected to produce higher growth rates and potentially improved survival that is

more similar to growth rates observed in more natural grow-shy‐out facilities13 Historically13 the13

large13 shallow13 ponds have produced very large fish when13 utilized at low13 fish density13 The

narrow13 deep earthen13 ponds are13 used to grow13 fry13 at high density in their first13 year of life

The major downside to unlined ponds is the difficulty in harvesting fish where a lined

pond might take 8-shy‐1013 people13 a half13 day13 to13 harvest13 lined13 ponds13 require13 intensive13 weeding13

to allow seines to be pulled and therefore require many more personnel-shy‐hours13 In addition13

to harvest challenges the shallow earthen ponds tend to suffer from13 dissolved oxygen

crashes during the summer Unlined ponds also may maintain higher13 populations13 of non-shy‐

target species such as bluegill sunfish mosquito fish and bullfrog tadpoles We measured

growth rates of suckers in a large shallow earthen pond for comparison to growth in lined

ponds13

Figure13 4 Lined13 and13 earthen ponds13 of similar dimensions (approx 1000000 gallons first

and second panels) and a large13 shallow13 earthen13 pond (third panel)

38

13

Effect of sorting on growth

Razorback13 suckers13 are13 currently13 sorted13 after their first13 year of growth13 They are13

typically removed from13 one of the13 upper earthen13 ponds and13 split into13 two13 lined13 ponds for

subsequent grow-shy‐out13 The larger13 fish (gt approximately 140 mm) are placed into one pond

and the smaller individuals in another It is possible that the larger fish were more

aggressive or adept13 at taking food so this sorting process is intended to allow smaller fish

to improve their growth rate

Effect of Ich on razorback sucker growth rates

We13 evaluated13 growth13 rates13 of razorback sucker13 in the13 presence13 and absence of the

ectoparasite13 Ich (Ichthiopthirus multifiliis) Ich outbreaks can occur in wild populations13 but

hatcheries13 have13 proven excellent locations13 for Ich because13 of very high fish densities13 which13

facilitate13 the13 transfer13 of Ich13 between13 fish This common fish parasite causes direct mortality13

to razorback13 suckers as well13 as secondary bacterial13 infections13

The open spring and13 ditch13 which13 provides water to the Bubbling13 Ponds Hatchery

has long13 been infested with mosquitofish (Gambusia affinis) that harbor13 the13 Ich parasite13

and allow13 it13 to enter the hatchery with incoming13 water13 The solution13 to13 the13 Ich problem13

was to remove the mosquitofish host using13 Rotenone Razorback13 sucker growth13 rates were13

then tracked in13 the absence of this parasite for 4 months and compared with growth rates

after Ich returned to the pond and from13 previous years

Methods

Razorback growth rate in lined ponds

On May 14 2008 141 razorback suckers were tagged with 12 mm PIT tags (1342

kHz) and placed in Pond 3 (approximately 1100000 gallons13 Figure13 4)13 at Bubbling13 Ponds

Fish Hatchery Fifty-shy‐three of these tags were recovered two months later when a large

Ichthyophthirius multifilis (Ich) outbreak killed many fish in the pond On October 15 2008

an additional13 145 PIT tagged13 fish were13 also placed into Pond13 3 On13 May13 14 2009 Pond13 3

was harvested and a total13 of 141 PIT tagged fish were recovered13 Of the tagged fish13 26 fish

had13 been13 in the13 pond since May13 of 2008 (378 days13 o growth) and 115 had been13 in13 the

39

13 40

pond since October13 15 2008 (211 days13 of growth) Numbers of fish in Pond 3 after the Ich

outbreak and for the majority of the period of growth were between 3 000 and 4000 fish

A Hobotempreg temperature13 logger13 was13 also13 installed13 in Pond 3 one meter below the water

surface13 near13 the13 outflow and13 recorded water temperature every 3 hours to allow analysis

of the effects of water temperature on growth rate (Figure13 5) This Hobotemp data is

representative of other pond temperatures throughout this study

In a second experiment 210 adult13 razorback suckers13 were13 PIT tagged13 on13 May 14

2009 and13 placed13 into13 Pond13 3 upper to13 evaluate13 growth13 rates13 of larger13 razorback suckers13 at

Bubbling13 Ponds Hatchery13 under current13 rearing13 conditions13 Size of these fish at tagging13

was (mean = 285 mm range = 205 ndash 396 mm) These fish remained in the pond for 257

days and were harvested on Jan 25 2010 to provide information on growth rates of larger

razorback suckers13 under13 current rearing conditions

Figure 513 Temperatures (degC) inrearing pond at BubblingPonds Hatchery from July toSept 2009 (top graph)13 andfrom Nov to Dec 2009 (Lowergraph) Temperaturesrecorded with a Hobotempregremote data logger13 every 3hours

13

Growth rate13 in an unlined pond

To document razorback sucker growth in earthen ponds we introduced13 225 tagged13

razorback suckers13 into13 Pond13 1 lower13 (Figure 4) in February 3 2010 Additional tagged fish

from13 other studies were added to the pond throughout the growing season and the density

of 1 lower reached a maximum13 of nearly 7000 fish in early summer 2010 Density was

reduced to approximately 6000 fish by capturing fish with hoop nets on June 3 2010 54 of

these fish were tagged fish and returned to 1 lower after being weighed and measured The

pond was harvested on January13 2713 2011 and a total13 of 254 tagged fish out13 of 4296 fish

total were removed from13 the pond The pond was harvested on January 27 2011 (358 days13

of growth) and the tagged fish were weighed and measured Total number of razorbacks in

the pond at harvest13 was 4296

Effect of sorting practices on growth rates

On March 1113 200913 Pond13 5 upper was13 harvested13 and13 split into13 two13 separate13 groups

Two hundred of the smaller fish (average size = 122 mm TL) were PIT tagged and placed

into13 Pond13 7 upper and13 200 of the13 larger13 fish (average = 160 mm TL) were PIT tagged and

placed int Pond13 8 upper Density13 in Pond13 7 was13 4500 fish and13 in Pond13 8 there13 were13 6500

fish These ponds were then harvested after 1 year and growth rates were compared to

give information on the effects of current sorting practices Hobotempreg temperature

loggers were installed in13 Ponds 7 and13 8 during13 the13 grow-shy‐out period with13 water13

temperature recorded every 2 hours13 (Figure13 6)

Effect of Ich on razorback sucker growth rates

Bubbling Ponds spring was treated with Rotenone (CFT Legumine 5) at a

concentration of 2 ppm13 to remove all mosquitofish from13 the spring The treatment

consisted of two treatments 6 hours in duration on two consecutive days (April 12 -shy‐ 13)

using13 drip13 stations13 and13 backpack sprayers13 followed13 by13 an13 additional 6 hours13 of

detoxification using sodium13 permanganate Although 12 mosquitofish were captured in the

spring pond the week following the treatments subsequent minnow trapping (20 traps

checked13 daily13 for 3 weeks) did not capture any additional fish until August 11 2010 when

41

13

juvenile mosquitofish were again detected in the spring pond Minnow traps have

subsequently been set daily with several hundred individuals removed To evaluate if Ich

was also again present in the spring we captured 15 mosquitofish from13 the spring pond on

three separate days and placed them13 in an aquaria at 25 degC with 5 longfin dace known to be

free of Ich These fish were monitored for 2 weeks with no signs of Ich developing This

indicates that even though mosquitofish have returned to the spring pond the parasite is no

longer present13 although how13 long13 this condition13 will13 persist13 is unknown13

On May 1113 201013 200 juvenile razorback13 suckers were harvested out13 of Pond 5

upper (2009 year Class from13 Dexter National Fish Hatchery) and were PIT tagged and

placed into Pond 8 to evaluate if growth rates at bubbling ponds hatchery have improved

following the renovation of the spring and the removal of the Ich parasite Unfortunately13

on Sept13 8 2010 Ich was13 again13 detected13 in Pond 8 and the pond was immediately seined

and 74 tagged fish were measured to obtain growth information for the 4-shy‐month period

during13 which13 the13 pond13 was13 Ich-shy‐free13

Figure13 6 Temperatures (degC) in rearingponds 7 and 8 at Bubbling Ponds Hatchery13 from March 2009 ndash March 201013 pond 7(top13 graph)13 and13 pond 8 (Lower13 graph)13 Temperatures recorded with a Hobotempregremote data logger every 3 hours

42

13

Results

Growth in Lined Ponds

Razorback suckers13 that had been13 in13 Pond 8 upper for the13 entire13 year13 grew an13

average of 0263 mmday (789 mmmonth) and razorback suckers that had been in the

pond for 7 months (Oct -shy‐ May) grew13 on13 average of 028 mmday (843 mmmonth) (Figure13

7) These growth13 rates13 did not significantly13 differ Fish density13 in Pond 3 during13 the13

majority of the growth period was13 00032 ndash 00036 fishgallon13 Additionally no13 significant

differences in growth rate were observed between fish smaller than 210 mm TL and fish

larger than 210 mm TL when all recaptured fish were combined

We also measured the growth rate of very large fish in a lined pond On Jan13 2513 201013

156 adult fish with PIT tags were recovered from13 Pond 3 upper13 These fish were13 in the13

pond for 257 days and experienced an average13 growth13 rate13 of 024mmday or 73

mmmonth (Figure13 7)13 This growth13 rate13 is slightly13 lower13 than13 the13 average13 growth13 rate13

observed13 at Bubbling13 Ponds Hatchery in other studies (0275 mmday 825 mmmonth)

but may not be biologically meaningful We would expect larger13 fish to13 have13 reduced

growth rates according to a typical Von Bertalanfy growth model (Bertalanffy 1957) but it

appears that13 over the size range we evaluated (300 -shy‐ 450 mm TL) growth rates have not

slowed significantly compared to that of smaller13 fish grown at Bubbling Ponds13 Hatchery

Growth13 of razorback suckers13 is known13 to13 slow as13 fish reach13 larger13 sizes but it appears13 this13

reduced growth rate may not really start to be biologically meaningful at Bubbling Ponds

Hatchery13 until razorback suckers13 exceed 450 mm TL

Growth in unlined ponds

Growth13 rates13 for the13 fish recaptured13 during13 the Pond 1 lower13 thinning13 (120 days13 in

the pond) was 024 plusmn 003 mmday (729 plusmn 090 mmmonth) (Figure13 8)13 Fish13 that were13 in

the pond for nearly the entire year grew13 an13 average13 of 024 plusmn 001 mmday (726 plusmn 027

mmmonth) These growth rates are surprisingly the lowest measured growth rates for

any part of our study and differ significantly from13 every other measured growth rate

except very large13 fish (Figure13 9)13 Separating13 out13 large fish that13 were in13 the pond for the

entire year makes no difference fish that were added to the pond at TL lt300 mm grew

43

13

Gro

wth

Rat

e (m

md

ay)

020

026

032

0244 plusmn 001 mmday (733 plusmn 028 mmmonth) and and those with TL gt= 300 mm at the

start of the experiment grew 022 plusmn 003 mmday (651 plusmn 101 mmmonth)

Razorback Growth Rates in Lined Ponds

Figure 7 Growth ofrazorback suckers in(mmday plusmn standard error)in Pond 8 upper in 2008-shy‐2009 An ANOVA did notdetect any significantdifferences

7 Months Full Year 300+ mm fish

Effects of sorting on growth

One hundred and seventy five tagged razorback suckers were recovered from13 Pond

8 upper13 on March13 24 2010 (378 days13 of growth)13 These were13 the13 larger sorted13 fish (gt140

mm TL) that came out of Pond13 5 on March13 11 2009 One13 hundred and13 twenty13 two13 tagged13

razorback suckers were also recovered from13 Pond13 7 upper on March13 31 2010 (385 days13 of

growth)13 These were13 the13 smaller sorted13 fish (lt140 mm TL) that came out of Pond13 5 on

March 1113 200913 No significant differences in growth rate (mmday) were observed among

larger fish in Pond 8 and smaller fish in Pond 7 (pgt005 ANOVA) (Figure 10)13 indicating

that13 sorting may have helped to offset the original slower growth trajectory of the smaller

fish Temperatures of Ponds 7 and 8 upper remained similar throughout the year13 (Figure

5)

44

13

13

13

Gro

wth

Rat

e (m

md

ay)

Gro

wth

Rat

e (m

md

ay)

020

026

032

020

026

032

Razorback Growth in an Unlined Pond

Figure 8 Growth of razorbacksuckers (mmday plusmn standard error) in Pond 1 lower (an unlined pond)in 2010-shy‐2011 An ANOVA did notdetect any significant differences

6 Months 12 Months lt 300 mm Fish 300+ mm Fish Growth Growth

Lined vs Earthen Ponds 1 year of growth

Figure 9 Growth of razorbacksuckers (mmday plusmn standard error) in lined and unlined ponds A t-shy‐test13 did not detect a significantdifference

Lined Pond Unlined Pond 1 Yr Growth 1 Yr Growth

45

13

Effect of Sorting G

row

th R

ate

(mm

day

) G

row

th R

ate

(mm

day

)

032

020

026

032

020

026

Smaller Fish Larger Fish

Effect of Ich

Figure 10 Average growthof razorback suckers(mmday plusmn standard error)that were size-shy‐sorted intosmall fish (pond 7) and largefish (pond 8) populations At-shy‐test did not detect asignificant difference

Figure 11 Average growth ofrazorback suckers (mmday plusmnstandard error) after Ich wasremovd from the hatcheryrsquos springand after Ich was again detected inthe pond The growth rate withoutIch is significantly higher than boththe rate after Ich and the ourstudyrsquos average annual growth ratein lined ponds (ANOVA p =00003)

Growth without Ich Growth With Ich Average Annual 4 months 4 months Growth Rate

46

13

Effect of Ich on razorback sucker growth rates

Seventy-shy‐four13 tagged13 razorback suckers13 were13 recovered from13 Pond 8 on September

15 2010 These fish had13 been13 in the pond for 4 months and experienced a growth rate of

032 mmday or 97 mmmonth (Figure13 11)13 This growth13 rate13 is significantly higher (p =

005 two sample t-shy‐test) than the mean growth rate for the same group13 of tagged fish after

Ich detection (022 mmday or 65 mmmonth) and significantly higher than any other

individual growth13 rates13 observed13 to13 date13 at Bubbling13 Ponds Hatchery13 (Figure13 11)13 If this13

growth13 rate13 were13 extended throughout13 the entire13 year13 fish on average from13 Ich-shy‐free13 ponds13

would be 16 mm longer than fish from13 ponds infested with Ich Studies conducted at

Bubbling Ponds hatchery in 2008 (Ward 2008) did not reveal any effects of the treatment

chemicals on razorback sucker growth rates so it13 is likely that13 the parasite outbreaks

themselves are causing reducing growth rates rather than the chemicals used to treat the

parasites13

Conclusions

Our results suggest that under typical hatchery operations (maximizing number of

fish produced)13 the growth13 rate13 of razorback13 suckers13 is relatively13 consistent at Bubbling13

Ponds hatchery13 at 02-shy‐03 mmday (6-shy‐9 mmmonth)13 but is lower than growth13 rates13 at

other13 facilities (02 ndash 18 mmday Ward et al 2007)13 This growth13 rate13 has13 been13 constant in

both lined and unlined ponds and at all fish densities we were able to measure To achieve13

growth13 rates13 substantially higher than this will likely require13 significant changes in rearing

practices that may not be practical in order to reach numerical production13 goals

Temperature is a key variable in fish growth but seasonal growth patterns

described13 above13 (Figure13 5) demonstrate that water temperatures are high enough in

winter to maintain razorback growth Differences in water temperature by season

currently13 do not fluctuate more than 10degC at Bubbling Ponds because of the continuous

supply of water flowing through each pond (approx 225 gallonsmin) These high water

flows appear to keep pond temperatures within the thermal preference13 for razorback

suckers13 (1213 -shy‐ 28 degC Bulkley and Pimentel 1983) throughout the entire year with

temperatures rarely dropping13 below 16deg13 C (Figures 513 6)13

47

13

Fish density is another key variable in fish growth and though the number of fish in

a pond during our study ranged from13 3000 to 700013 fish we13 did not find any13 correlation13

between13 density and growth rate13 This might yield two conclusions First13 razorback

growth13 may be changed equally13 by13 densities13 at the13 hatchery13 (ie13 a density13 of 3000 fish in a

pond is as stressful13 for razorbacks as a density13 of 7000 fish) An alternative is that other

factors13 such as disease outbreaks have13 stronger13 control over fish growth13 than13 density13

Fish density13 would13 have13 to13 be13 experimentally manipulated to test13 this13 and hatchery

operations (producing the maximum13 number of fish) prevented our manipulating density13

in ponds for this13 work The trouble with manipulating density demonstrates the difficulties

associated with changing13 hatchery13 practices experimenting with density would have

prevented BPH from13 meeting13 production13 goals Given that the stocking of smaller

razorbacks has met with very little success perhaps BPH goals could be changed from13

producing 12000 fish at 300+ mm per year to a smaller number of very large fish each

year Growing13 fewer13 larger13 fish could potentially be accomplished in the same time frame

as more smaller fish but a better understanding of how density alters growth rate would

be required to be confident13 of this

The very slow growth13 in the13 earthen13 unlined13 Pond 1 lower13 was very surprising We13

had13 anticipated13 that the13 diversified diet13 cover and13 other13 habitat features13 provided by13

unlined ponds would yield dramatically increased growth rates However these traits were

not enough to offset high fish densities and in fact the unlined pond in our study13 suffered

mortality to bring densities down to that observed normally in lined ponds

Our data13 suggest13 that razorbacks13 sucker13 growth13 rates13 are13 higher in lined13 ponds13

However we13 think the reasons13 for the13 very slow growth we observed13 in the13 unlined13 pond13

in our study13 is instead13 linked13 to13 the13 usage13 of Pond 1 lower13 during13 the13 study13 rather13 than13

intrinsic13 slow growth13 in earthen13 ponds First the pond was at extremely high density for at

least part of the study The volume of Pond 1 lower has not been estimated but hatchery

managers suggest 1500-shy‐2000 fish is an appropriate number of individuals so this pond

was at a very high density for much of the experiment Second dissolved oxygen is often

very low in the13 large13 earthen13 ponds during the heat of summer much lower than that of

lined ponds This will both limit the number of fish that can survive in the pond and almost

certainly13 increases stress13 of these13 fish potentially13 reducing growth13 The DO crashes also13

48

13

limit the amount of feed hatchery managers can give fish in these ponds sometimes for

days or weeks at a time which further reduces growth during warm13 weather

Our data13 suggests that13 growth rates at the Bubbling13 Ponds Fish Hatchery are likely

as high as possible given13 the pond densities required to meet production goals and the Ich-shy‐

infested water that feeds the facility Sorting practices are successful in helping as many

fish as possible reach stocking length as fast as possible Unlined ponds may be able to

grow13 large13 fish at low13 densities13 but whatever factors allow13 for that13 growth are not13 able to

overcome high fish density The removal of invasive13 fis that act as13 a host for the13 parasite13

Ich fish from13 the Bubbling13 Ponds spring13 allowed the highest13 growth rate at 032 mmday13

(96 mmmonth) but that growth rate decreased again as Ich re-shy‐infested13 the13 hatchery13

Consistently13 achieving13 growth13 rates13 as high or substantially13 higher than13 this13 will likely13

require13 significant changes in rearing practices that may not be practical in order to13 reach13

numerical production13 goals

Two major changes that might result in higher growth rates are substantially

reducing fish density and modifying the way spring water is delivered to the facility (via

either repeated chemical treatments or enclosed concrete water diversions) to eliminate

Ich from13 the hatchery source water Other potential changes not address by our work

include13 flow-shy‐training razorbacks much previous literature including MSCP-shy‐funded13 work

on razorback suckers13 suggests13 that fish growing13 in flowing water will grow13 faster than fish

in still water (Jorgensen and Jobling 1994) Furthermore there are a wide variety of

potential benefits associated with growing13 fish13 in flowing13 water in addition13 to increased

growth13 rates13 (Davidson13 199713 Castro13 et al13 2011) Another option13 for increasing13 growth13

rates13 include13 changing to13 intensive13 culture13 in large circular13 tanks

Finally given that the stocking of smaller razorbacks has met with very little

success13 perhaps13 BPH13 goals13 could13 be13 changed from13 producing 12000 fish at 300+ mm per

year to a smaller number of very large fish each year Growing fewer larger fish could

potentially be accomplished in the same time frame as more smaller fish but a better

understanding13 of how density13 alters growth13 rate13 would13 be13 required to13 be13 confident of this

49

13

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower13 Colorado13 River Multi-shy‐Species13

Conservation Program13 (LCRMSCP) under Work Task C10 We13 thank Ty Wolters13 Tom13

Burke13 and Eric13 Volkman for their support of this research and Frank Agygos and Dave

Billingsly13 of the Bubbling13 Ponds Fish Hatchery13 for their willingness to participate in13 this

research13 and13 for their technical assistance We also thank the LCRMSCP fish group from13

Boulder City13 NV for their assistance with harvesting13 ponds and tagging13 fish13

50

13

Literature13 CitedAnders P J 1998 Conservation aquaculture and endangered species can objective science13

prevail13 over risk13 anxiety Fisheries 23(11) 28-shy‐31

Anderson R O and R M Nuemann 1996 Length weight and associated structural indicesPages 447 ndash 482 in B R Murphy13 and D13 W Willis13 editors13 Fisheries techniques13 2ndedtion American Fisheries13 Society13 Bethesda13 Maryland

Bain M B J T Finn and H E Brooks 1988 Streamflow regulation and fish communitystructure13 Ecology13 69382-shy‐392

Bays J H Zarbock R Whitman and T Murphy 2005 Conceptual design and managementof native13 fish refugia on the13 lower13 Colorado13 River In13 CL Spring13 and13 S Leoneditors Proceedings of two symposia Restoring native fish to the lower ColoradoRiver13 interactions13 of native and non-shy‐native13 fishes 13ndash1413 July13 1999 Las13 Vegas13 Nevada13 Restoring13 natural function within a modified riverine environment thelower Colorado River13 8ndash913 July13 1998 U S Fish and13 Wildlife13 Service Southwestern13 Region Albuquerque New Mexico Pages 167-shy‐177

Bertalanffy L Von 1957 Quantitative laws in metabolism13 and growth13 Q Rev Biology 32217 ndash 231

Bingham T B Scheer and C McAda 2003 Propagation facilities in Grand Valley (24 RoadHatchery Horsethief13 Ponds and13 grow-shy‐out ponds) for captive13 rearing13 ofendangered13 fishes for the13 upper13 Colorado13 River basin13 Colorado River RecoveryProgram FY2003 annual project report13 US Fish and13 Wildlife13 Service GrandJunction13 4pp

Birchell G J and K Christopherson 2004 Survival growth and recruitment of larval andjuvenile razorback13 sucker (Xyrauchen texanus) introduced13 into13 floodplain13 depressions13 of the13 Green River Utah13 Final report13 Upper13 Colorado13 RiverEndangered Fish Recovery Program13 Project No C-shy‐6RZ Publication Number 04-shy‐1513 Utah13 Division of Wildlife13 Resources Salt Lake13 City13 Utah13 67 pages

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Brett J R 1979 Environmental Factors and growth pages 599-shy‐67513 InW S Hoar13 D13 J13 Randall and J R Brett (eds) Fish Physiology Volume 8 Bioenergetics and GrowthAcademic Press New York

Brooks J E 1986 Annual reintroduction and monitoring report for razorback suckerXyrauchen texanus in the Gila River Basin Arizona 1985 US Fish and WildlifeService13 Offices of Endangered13 Species and Fishery13 Resources Albuquerque 23 pp

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Brunson13 R E and K D13 Christopherson13 200513 Larval13 razorback13 sucker and bonytailsurvival and13 growth13 in the13 presence13 of nonnative13 fish in the13 Baeser13 floodplainwetland of the middle Green River Final report prepared for Upper13 Colorado RiverBasin Endangered Fish Recovery Program Project No C-shy‐6-shy‐rz-shy‐bt Publication13 No 05-shy‐26 Utah13 Division of Wildlife13 Resources13 Vernal13 32 pp

Bulkley R V and R Pimentel 1983 Temperature preference and avoidance by adultrazorback suckers Transactions of the American Fisheries Society 112601-shy‐607

Burke13 T13 199513 Rearing13 wild razorback13 sucker larvae in13 lake-shy‐side13 backwaters13 LakeMohave ArizonaNevada Proceedings of the Desert Fishes Council 2635

Busacker G P I R Adelman and E M Goolish13 199013 Growth13 Pages 363 ndash 387 in C BSchreck and p B Moyle editors Methods for fish biology American FisheriesSociety Bethesda Maryland

Castro V B Grisdale-shy‐Helland S J Helland T Kristensen S M Jorgensen J Helgrud13 GClaireaux A P Farrell A Krasnov and H Takle 2011 Aerobic training stimulatesgrowth and promotes disease resistance in Atlantic salmon (Salmo salar)Comparative Biochemistry and Physiology -shy‐ Part A Molecular amp IntegrativePhysiology13 160(2) 278-shy‐290

Czapla T E 2002 Facilities plan for the production of endangered fishes to meet statestocking13 plans13 as13 part of the13 Upper13 Colorado13 River Endangered13 Fish RecoveryProgram Upper Colorado River Basin Recovery Implementation Program US Fishand Wildlife Service13 Denver13 9 pp

Davidson W 1997 The effects13 of exercise13 training on teleost fish a review of recentliterature Comput Biochem Physiol 117A67ndash75

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Kaeding L R and D B Osmundson 198913 Colorado13 Squawfish13 and13 razorback sucker grow-shy‐out pond studies as part of conservation measures for the green mountain andRuedi reservoir water sales Final report for agreement number 6-shy‐AA-shy‐60-shy‐00150

Koebele13 B P13 198513 Growth and the size hierarchy effect an experimental assessment ofthree proposed mechanisms activity differences disproportional food acquisition13 pysiological stress Environmental Biology of Fishes 12 181-shy‐188

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Marsh13 P13 C13 1987a13 Digestive tract13 contents13 of adult razorback suckers13 in Lake13 MohaveArizona-shy‐Nevada Transactions of the American Fisheries Society 116117-shy‐119

Marsh P C 1987b Native fishes at Buenos Aires National Wildlife Refuge and ArizonaState University Research Park Arizona opportunities for management researchand public13 education13 on13 endangered species13 Proceedings of the Desert13 FishesCouncil 1967-shy‐78

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Marsh P C B R Kesner and C A Pacey 2005 Repatriation as s management strategy13 to13 conserve a critically13 imperiled fish species North American Journal of FisheriesManagement 25 547-shy‐556

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Marsh13 P13 C13 and J13 E Brooks13 198913 Predation13 by ictalurid catfishes as a deterrent13 toreestablishment of hatchery-shy‐reared13 razorback sucker The Southwestern Naturalist34188-shy‐195

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Minckley13 C13 O and M LaBarbara13 199913 Report13 on13 native fish grow-shy‐out facilities13 at Cibolaand Imperial National Wildlife Refuges 1993-shy‐199513 US Fish and13 Wildlife Service13 Parker Fishery Resources Office Parker Arizona

Modde13 T13 199613 Juvenile razorback sucker (Xyrauchen texanus) in a managed wetlandadjacent13 to the Green13 River13 Great13 Basin13 Naturalist13 56375-shy‐376

Modde T KP Burnham and E J Wick 1996 Population status of the razorback sucker13 inthe middle Green River (USA) Conservation13 biology 10 110-shy‐119

Modde13 T13 and G13 B Haines13 200513 Survival13 and growth of stocked razorback13 sucker andbonytail in multiple floodplain wetlands of the middle Green River under resetconditions13 Final report prepared for Upper Colorado13 River13 Basin RecoveryImplimentation Program US Fish and Wildlife Service Vernal 66 pp

54

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Modde T Z H Bowen and D C Kitcheyan 2005 Spatial and temporal use of a spawning13 site in the middle Green River by wild hatchery-shy‐reared13 razorback suckers13 Transactions of the American Fisheries Society 134937-shy‐944

Mueller13 G13 199213 The native fish work13 group13 -shy‐ a multiagency endeavor to improve thestatus of the razorback sucker in Lake Mohave AZ-shy‐NV13 Proceedings of the DesertFishes Council 2369

Mueller G 1995 A program13 for maintaining the razorback sucker in Lake MohaveAmerican Fisheries Society Symposium 15127-shy‐135

Mueller13 G13 200613 Ecology of the bonytail13 and razorback13 sucker and the role of offchannelhabitats13 in their13 recovery Scientific13 investigations13 report 2006-shy‐5065 US GeologicalSurvey13 Denver

Mueller G and E Wick 1998 Testing of golf course ponds at Page Arizona for suitability13 as grow-shy‐out facility for razorback sucker using surplus fish from13 Ouray NationalFish Hatchery National Park Service US Fish and13 Wildlife13 Service and UtahDivision of Wildlife13 Resources 28 pages

Mueller13 G13 and T13 Burke13 200513 Survival13 of young13 razorback13 sucker (Xyrauchen texanus) inrelation to13 stocking rates13 (fishha)13 and13 in the presence13 or absence13 of predatorcommunities in Lake Mohave Arizona-shy‐Nevada13 Pages13 155-shy‐16313 in Proceedings of two13 symposia restoring native fish to the lower Colorado River interaction13 of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 Nevada US Fish and Wildlife13 Service Southwest Region Albuquerque New Mexico

Mueller13 G13 J13 Carpenter13 and P13 C13 Marsh13 200413 Cibola13 High Levee Pond annual report 2004US Geological Survey Fort Collins13 Science Center13 Colorado13 and Arizona StateUniversity Tempe 23 pages

Nesler T P K Christopherson J M Hudson C W McAda F Pfeifer and T E Czapla 2003An integrated stocking plan for razorback sucker bonytail and Colorado13 pikeminnow for the Upper Colorado River Endangered Fish Recovery ProgramAddendum13 to State Stocking Plans Upper Colorado River Basin Recovery13 Implementation Program 12 pp

Papoulias13 D and W13 L Minckley13 1992 Effects13 of foo availability13 on survival and growth13 of larval razorback suckers13 in ponds Transactions of the American Fisheries Society121340-shy‐355

Paukert13 C P D L Ward13 P J Sponholtz13 and K13 D Hilwig13 Effects13 of repeated hoopnetting13 on bonytail chub13 Journal of Freshwater13 Ecology13 20(4) 649-shy‐653

Pfeifer F M13 C Baker13 and M13 Montagne13 199913 Propagation13 facilities13 in the13 Grand Valley13 (24 Road13 Hatchery13 Horsethief13 Ponds and13 grow-shy‐out ponds) for captive rearing of

55

13

endangered13 fishes for the13 Upper Colorado13 River Basin13 Colorado13 River Recovery13 Program FY 99 annual project report Project No 29a13 US Fish and Wildlife Service13 Grand13 Junction13 5pp

Pfeifer F S Seversen and M Montagne 2003 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2003 annual reportProject No 29b13 US Fish and Wildlife13 Service Vernal13 4pp

Rabago-shy‐Castro J L Sanchez13 J G Perez-shy‐Castaneda R and13 Gonzalez-shy‐Gonzlez A 2006Effects of the prophylactic use of Romet-shy‐3013 and13 copper13 sulfate13 on growth13 condition13 and feeding13 indicies in13 channel13 catfish (Ictalurus punctatus) Aquaculture 253 343-shy‐349

Reinitz GL L E Orme and F N Hitzel 1979 Variations of body compositio and growth13 among strains of rainbow trout Transactions of the American Fisheries Society 108204-shy‐207

Ruppert13 J13 B P B Holden13 and P D Abate 1999 Age estimation and growth of razorbacksucker13 Xyrauchen texanus in Lake13 Mead Nevada Proceedings13 of the Desert FishesCouncil 3040

Schnoor K D and J Logan 2002 Operation and maintenance of JW Mumma nativeaquatic13 species restoration facility Colorado Colorado River Recovery Program FY2002 annual project report13 Project No 29d Colorado13 Division of Wildlife Alamosa3pp

Salisbury13 L13 1998 Factors13 affecting razorback13 sucker growth13 in Lake13 Mohave backwaters13 MS Thesis13 Unviersity13 of Nevada13 Las13 Vegas

Schooley J13 D13 and P C13 Marsh13 2007 Stocking of endangerdd13 razorback13 suckers13 in thelower Colorado River Basin13 over three decades 1974-shy‐2004 North American Journalof Fisheries Management 27 43-shy‐51

Severson S H H M Tyus and G B Haines 1992 An evaluation of feeds for raisingrazorback sucker Xyrauchen texanus Journal of Applied Aquaculture 155-shy‐65

Toney D P 1974 Observations13 on the13 propagation13 and13 rearing13 of two13 endangered species13 in a hatchery environment Proceedings of the Annual Conference of the Western13 Association of State Game and Fish Commissions 54 252-shy‐259

Tyus H M13 1998 Razorback sucker13 (Xyrauchen texanus) recovery plan13 University13 ofColorado Center for Limnology Boulder13 76 pages

Tyus H M13 and13 S H Severson 1990 Growth13 and13 survival of larval razorback suckers fedfive formulated diets The Progressive Fish Culturist 52197-shy‐200

56

13

Ulibarri M E 2003 Annual report fiscal year 2001 Dexter National Fish Hatchery13 andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 26 pages

Ulibarri M E 2003 Annual report fiscal year 2002 Dexter National Fish Hatchery andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 59 pages

USBR 2006 Lower13 Colorado13 River Multi-shy‐Species Conservation Program final fishaugmentation plan Boulder City 19 pp

USFWS 2002 Razorback sucker (Xyraouchen texanus) recovery goals Amendment andsupplement to the Razorback Sucker Recovery Plan13 US Fish and Wildlife Service13 Region 6 Denver13 Colorado

USFWS 1999 Annual report 1999 Ouray National Fish Hatchery Vernal 25pp

USFWS 2004 Management plan for the big-shy‐river13 fishes of the13 lower13 Colorado13 river basinamendment and supplement to the bonytail humpback chub Coloradopikeminnow and razorback sucker recovery plans

USFWS13 2005 Station13 profile13 of the13 Dexter13 National Fish Hatchery13 and Technology CenterUS Fish and Wildlife13 Service Dexter

Valdez R A P G Mangan R Smith and B Nilson 1982 Upper Colorado River fisheriesinvestigations13 inW H Miller J J Valentine D L Archer H M Tyus R A Valdezand L13 Kaeding13 editors13 Colorado River Fishery13 Project13 Part 2 Field13 investigations13 US Bureau of Reclamation Salt Lake City Utah

WBNFH 2004 Culture methods of the endangered razorback sucker Xyrauchen texanusUS Fish and Wildlife13 Service Willow Beach National Fish Hatchery13 8 pp

Ward D 2008 Effects of disease treatments on growth of razorback sucker ReportSubmitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 Inpartial fulfillment of work task C10 agreement number 06FG30039

Ward13 D13 M Childs and W Persons 2007 Factors13 affecting13 growth13 of razorback sucker13 (Xyrauchen texanus) in captivity Literature review and knowledge assessmentReport Submitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 In partial fulfillment of work task C10 agreement number 06FG30039

57

Appendices

Appendix 1 Survey Questions Survey of Razorback Sucker Culture in the

Southwestern United States

The enclosed survey is being distributed by the Arizona Game and Fish Department to razorback sucker culture facilities throughout

the Southwestern United States The purpose of this survey is to consolidate information regarding culture of this species so that

appropriate facility improvements can be considered for Bubbling Ponds Hatchery in Arizona Specifically we wish to increase

growth rate and production efficiency at the hatchery Information gathered in this survey will be summarized in a final report to US

Bureau of Reclamation in Boulder City NV and disseminated to all facilities that participate in the survey A workshop to discuss

the findings of this study as well as to share general information concerning razorback sucker culture will be organized by the

Arizona Game and Fish Department at the conclusion of this study and all participants will be invited

Thank you for taking the time to fill out this survey Please contact Mike Childs if you have questions or would like to discuss the

survey

Mike Childs

mchildssedonanet

(928) 639-1346

(928) 634-1279

Facility_____________________________________ Date___________________

Contact Phone _____________________________

ContactPerson_______________________________

Contact Email _______________________________

1 Water quality ranges at this culture facility

Season

Spring (Mar-May) Summer (Jun-Aug) Fall (Sept-Nov) Winter (Dec-Feb)

Temperature (C)

PH

DO (mgL)

PO4 (mgL)

TDS (mgL)

Hardness (mgL)

CaCO3

Pathogens

37

13

Table13 3 Water13 quality13 ranges13 at each13 culture facility$amp ($)$++) -+$

-)amp012$)32$45 -6+)01763865 9$01-+3lt5 =amp+)01gt+39+5 $amp()amp+ ++)$6)+01A5

J gtLNL01O5 8P$ampamp401O5 ($Q+

BC3DE DD3DF BG3DB KLM3MLE KLH3MLI KLH3MLF CLM3BFLE CLM3BFLE CLM3BFLE

RQS0Aamp$ RQS0Aamp$ RQS0Aamp$ )ampQTamp$ )ampQTamp$ )ampQTamp$

8+)$O(6+T$ 8+)$ 8+)$ A6$)amp A6$)amp A6$)amp

BH3BI KLH3MLE CLM3BFLE

RQS0Aamp$ )ampQTamp$ 8+)$ A6$)amp

-01 ++)$6)+01A5 J gtLNL01O5 8P$ampamp401O5 ($Q+

BK3DE DD3DM BK3DE KLC3MLC KLC MLC DLM3GLK DLM3GLK DLM3GLK BIC3BMM BIC3BMM BIC3BMM

2ampamp$03040UQ$0amp0)6Q0amp0UampQ0ampamp0VampQ

BE3BI KLC

DLM3GLK BIC3BMM

213amp+(4amp50amp ++)$6)+01A5 J gtLNL01O5 8P$ampamp401O5 ($Q+

DH3DC DH3DC DH3DC KLK3MLE KLK3MLE KLK3MLE KLE3KLC ILC3KLE ILE3ILC BEE BEE BEE

+0$0amp+amplt+066)+0V$ampamp4S0RQ0$0)TP0T

DH3DC KLK3MLE FLC3ILC BEE

6137 ++)$6)+01A5 J gtLNL01O5 8P$ampamp401O5 ($Q+

BB3DC BB3DC BB3DC KLF3MLD KLF3MLD KLF3MLD CLE3BD CLE3KLD CLE3KLD BBG BBG BBG Aamp$ Aamp$ Aamp$

BB3DC KLF3MLD CLE3KLD BBG Aamp$

8$$9(35 ++)$6)+01A5 J gtLNL01O5 8P$ampamp401O5 ($Q+

BK3DE DE3DC BK3DE KLC3MLE KLC3MLE KLC3MLE HLE3GLE HLE3ILE HLE3GLE HEE3FEE HEE3FEE HEE3FEE RQS0Aamp$ RQS0Aamp$ RQS0Aamp$ A6$)amp A6$)amp A6$)amp 8+)$ 8+)$ 8+)$

BH3BM KLC3MLE FLE3GLE HEE3FEE RQS0Aamp$ A6$)amp 8+)$

lt3$+ ++)$6)+01A5 J gtLNL01O5 8P$ampamp401O5 ($Q+

BG3DI DI3DM BM3DM KLK3MLD KLK3MLD KLK3MLD FLE3BDLE FLE3BDLE FLE3BDLE DDI DDI DDI

A6$)amp

BF3BM KLK3MLD FLE3BDLE DDI

Bubbling Ponds State13 fish Hatchery13

Bubbling Ponds Fish Hatchery in Arizona does not maintain razorback sucker

broodstock on site Razorback suckers are received either as juveniles from13 Willow Beach

National Fish Hatchery13 or as13 newly-shy‐hatched larvae from13 Dexter13 National Fish Hatchery

Larval fish are13 typically13 placed13 into13 an unfertilized unlined 0613 acre13 pond13 in the13 spring In

September the pond is harvested by draining the pond and seining All fish that have

reached the target size (300 mm TL) are stocked Fish that are too small to stock are split

up equally between the six remaining grow-shy‐out pond at an13 average13 density13 of about 5000

ndash 7000 fish per pond Fish are fed by hand at approximately 25 body weight split

between morning and evening feedings Fish are either fed a catfish diet made by Rangenreg

13

13

that is enriched with spirulina and krill or razorback sucker diet made by Silvercupreg

depending on availability Fish are monitored visually and by sampling using a cast net

When a large number13 of fish have13 grown to13 the13 target size they13 are13 harvested13 by13 draining

the pond and seining13 Fish are again13 sorted by hand and the largest13 fish are stocked13 Fish

that13 have not13 reached the target13 size are returned to the ponds for further grow-shy‐out13 On13

average it13 takes one to two years for fish to reach the target13 size with fish growing13 an

average of 06 mmday Target numbers for production are 12000 razorback suckers

annually (300 mm TL) The biggest difficulty in rearing razorback suckers at Bubbling

Ponds13 Fish Hatchery13 is protozoan13 parasite13 infestations13 (Ich) and13 associated13 bacterial

infections that come from13 an open spring source that is inhabited by mosquitofish

Dexter National Fish Hatchery13

Dexter National Fish Hatchery maintains four separate razorback sucker13

broodstocks13 These fish are spawned on13 site and larval13 fish are placed directly into 01 acre

ponds at a density13 of about 20000 larvae13 per pond (50 ndash 100 thousand13 per13 acre)13 Ponds

are fertilized with alfalfa13 pellets and superphosphate two weeks prior to receiving13 larvae to

produce13 natural13 feed for larval13 fish13 Ponds are13 fertilized again with alfalfa13 pellets one week

after larvae are introduced13 Fish are fed a catfish starter diet13 (sizes 1-shy‐3) made by Rangenreg

that13 is enhanced with spirulina13 and krill13 and then switched over to the razorback13 diet13 once

they are large enough to eat 1mm13 crumble Fish are fed twice a day by hand four days a

week13 at 25-shy‐60 body weight Feed ration is decreased if excess feed is seen remaining

on the13 pond bottom13 following feedings Fish are not graded or sorted during this grow-shy‐out

period Razorback suckers are harvested in the fall by draining ponds completely Fish are

sorted13 at harvest and13 distributed13 to13 other13 facilities13 for further13 grow-shy‐out depending on13

current size requirements Razorback suckers are on average 100 ndash 200 mm TL after the

first growing13 season13 and13 generally13 take13 1 -shy‐18 months for a majority of the fish to reach

300 mm TL There are 16 different species of fish maintained at Dexter National13 Fish13

Hatchery13 and13 having sufficient pond13 space13 to13 grow out separate13 groups13 of fish is the13

limiting factor for production of razorback suckers at this location

14

13

Grand Valley13 Native13 Fish Facility13

The Grand Valley Native Fish Facility maintains its own brood stock13 in13 eight13 ponds

located at the Horsethief Basin Wildlife Area in Grand Junction Colorado Fish are

spawned13 on site13 and13 larvae13 are13 reared13 indoors in fiberglass13 tanks13 at the13 24-shy‐Road13 Fish13

Hatchery13 in Grand13 Junction The 24-shy‐Road13 Hatchery13 consists of two13 separate13 recirculating13

systems that operate using de-shy‐chlorinated13 city13 water13 and two13 large13 fluidized-shy‐ bed sand

filters13 and13 rotating-shy‐drum13 filters for waste removal Fish are held in 4-shy‐foot (n=78) or 8-shy‐foot

(n=14) diameter fiberglass tanks Larval fish are started on prepared feeds immediately

after swim-shy‐up and fed exclusively razorback feeds made by Silvercupreg Fish are started on

a 0-shy‐250 micron razorback diet for the first 10-shy‐1213 days13 and13 then13 fed with13 gradually13

increasing13 feed sizes based13 on observations of feeding13 (250 ndash 400 micron 1 starter) Feed

sizes are mixed when transitioning to the next larger feed size These razorback diets are

specially sifted by Dr Rick Barrows (USDA13 Hagerman experiment station Idaho)

Razorbacks13 are13 typically eating 1mm13 extruded pellets by the time they are 35 to 4 inches

in length Fish are fed approximately 70 body weight per day initially and then gradually

reduced to 15 body weight by the time they reach the 300 mm TL target size Fish are

fed seven days13 a week using13 12-shy‐hr13 belt feeders It takes13 12-shy‐16 months to grow fish to the

target13 size in13 the hatchery13

Razorback suckers are sorted after three months and culled to about 4000 fish per

family lot Culled fish are stocked into leased grow-shy‐out ponds Stocking densities for

juveniles in these ponds is based on previous13 stocking and harvest13 rates13 and is pond

specific13 Grow-shy‐out ponds are13 harvested13 periodically13 using Fyke13 nets13 or trap13 nets13 and13 fish of

the target size are stocked Disease problems (Ich Lernea) water quality problems (low

DO) and difficulty in removing all of the fish are challenges for grow-shy‐out of razorback

suckers13 in these13 natural ponds13

Fish reared13 in the13 24-shy‐Road facility are sorted again at four to five months of age into

small and large size groups to obtain more uniform13 growth rates Batch estimates of fish

weight are done every month for each tank A group of fish are weighed and counted to

give an average weight for the tank with lengths estimated based on a lengthweight chart13

The biggest difficulties13 for growing13 out razorback suckers13 at the13 24-shy‐Road13 Fish13 Hatchery13 are13

insufficient space and water flow (oxygen) to grow fish to the target size At the Horsethief

15

13

Basin13 Ponds where broodstock13 are reared13 diseases such as Ich are problematic because

water is pumped directly from13 the Colorado River

Ouray13 National Fish Hatchery13

Ouray13 National13 Fish Hatchery maintains its own broodstock and13 spawns13 fish on-shy‐site13

Larvae are transferred from13 indoor hatching tanks to unfertilized 02 acre outdoor ponds

and stocked at densities 10000 ndash 20000 larvae13 per13 pond13 Even13 though13 outdoor13 ponds13 are13

covered with13 bird13 netting13 avian predators13 still get caught in the13 nets13 if they13 can see fish

Ponds are dyed blue13 as the13 fish grow to13 prevent avian predation13 While in the outdoor

ponds13 fish13 are13 fed a slow-shy‐sinking salmon diet made by Silvercupreg twice daily by hand

Amount of feed is based on periodic sample counts Fish are grown until late September at

which time temperatures require that all fish13 other13 than13 adult broodstock13 be13 brought

inside for the winter Ponds are drained completely and fish are sorted by hand Fish that

have reached the target size (300 mm TL) are stocked into the Green and Colorado Rivers

All remaining fish are moved indoors13 and13 held13 in three-shy‐foot (n= 30) or eight-shy‐foot (n=27)

diameter circular tanks On average it takes 12 ndash 18 months to grow fish to the 300 mm TL

at Ouray13 hatchery13

Razorback suckers are held during the winter in a recirculating system13 that

operates13 using13 two13 large13 fluidized-shy‐bed sand filters and a rotating-shy‐drum13 filter for solids

removal Fish are fed the Silvercupreg razorback diet using belt feeders There is currently

capacity13 to13 hold13 only13 20000 200-shy‐300 mm TL fish inside the facility and any extra fish13 are13

stocked13 into13 floodplain-shy‐wetlands or used for research purposes13 Ouray no longer leases

any private grow-shy‐out ponds Grow-shy‐out ponds were troublesome due to poor water quality

harvesting13 difficulties13 and13 non-shy‐native13 fish introductions13 The biggest difficulty13 for

production13 of razorback13 suckers at the Ouray13 National13 Fish13 Hatchery13 is space13 during13 the

winter to maintain large numbers of fish and high iron and manganese in the well water

that must be filtered out prior to use

16

13

Willow Beach National Fish Hatchery13

Willow13 Beach National13 Fish Hatchery receives wild-shy‐caught larvae from13 Lake

Mohave Larvae are treated for diseases with formalin and malachite green and placed in

45 ten-shy‐gallon13 flow-shy‐through aquaria13 Recirculated13 solar heated water13 22-shy‐25deg C is used to13

allow production of warm13 water fish at this traditionally cold water facility (Figiel 2003

Figiel et al 2005) Fish are fed brine shrimp nauplii to satiation every hour and after 14

days small amounts of specialized larval fish diet (Encapsulon13 Cyclopeeze13 spirulina13 and

artificial plankton) are introduced After 30-shy‐6013 days13 fish are13 transferred13 to13 six13 32-shy‐gallon13

fiberglass troughs at densities of 1000 to 1500 fish per tank and then a month later moved

outside13 to13 eight recirculating13 raceways that use a combination of well water and solar-shy‐

heated water to maintain temperatures of 22 ndash 25deg C during the summer months

When13 in13 the outside raceways13 fish are fed the razorback13 diet13 using13 belt13 feeders and

fed by13 hand13 at 10 -shy‐ 70 body13 weight per13 day Feed amount is adjusted based on sample

counts according to a feed conversion program13 developed for razorback suckers by Willow

Beach Hatchery personnel This program13 uses length and number-shy‐per-shy‐pound generated

from13 several years of razorback growth data (Figure13 1) Fish are13 sorted13 opportunistically13

and are not handled during the summer months when water temperatures are above 20degC

In 2004 the target size for stocking was 325 mm TL or greater (WBNFH 2004) with a

target13 of producing13 6000 fish per year Reaching this13 target size usually13 takes13 two13 growing13

seasons13 The biggest difficulty13 in rearing13 razorback suckers13 at Willow Beach13 National Fish

Hatchery13 is insufficient space13 to13 grow fish to13 increased13 target sizes (400-shy‐500 mm TL)

Uvalde13 National Fish Hatchery13

Uvalde13 National Fish Hatchery13 in Texas13 receives 35000 ndash 60000 razorback sucker13

fry annually in MarchApril from13 Dexter National Fish Hatchery The fry are acclimated in

bags submerged in the pond for a minimum13 of one hour and released into13 a 1 acre13 fertilized13

pond where they are reared for the remainder of the summer Fingerlings are fed a starter

razorback diet when they reach approximately 50 mm TL In AprilMay the previous year

class of razorbacks are captured from13 their over-shy‐wintering pond enumerated graded and

split into13 one-shy‐acre grow-shy‐out ponds Approximately 4000 ndash 5000 fish will be13 placed13 in each13

one acre pond for summer grow-shy‐out Fish are reared for approximately 150 days (May ndash

17

13

Oct) and fed the Bozeman razorback diet two times a day five days a week at 15 ndash 30

body weight per day based on average water temperature

Figure 1 Relationship between length and number of fish per pound

In general13 juvenile razorback13 suckers (received as fry13 during13 the previous spring)13

reach the target size of 300 mm TL in approximately 6 months In 20062007 Uvalde

produced 6000 razorback suckers 300 mm TL for introduction into the San Juan River

Starting13 in 2008 Uvalde NFH will be producing13 and distributing13 12000-shy‐ 300 mm TL

razorbacks for stocking into the San Juan River Predation from13 migrating cormorants has

occurred but timing of harvest and over wintering protection methods such as covering

ponds with netting or placing fish indoors helps to minimize losses during the cormorant

migration (November to March) Uvalde has experienced razorback mortalities because of

bacterial problems but these are usually resolved through the use of oxytetracyline

medicated feed

Overview13 of Differences in Culture Methods

Several differences were noted when conducting surveys at each of the five main

production facilities for razorback sucker (See Appendix 3) These differences include

different stocking13 and13 rearing13 densities13 (Table13 4-shy‐5) various feeding regimes and type of

18

13

lt=amp

feeds (Table 7) as well as differences in grading or sorting practices Some of these

differences are13 related13 to13 whether13 or not razorback suckers13 are13 being13 reared13 in extensive-shy‐

culture13 facilities13 (ponds) or intensive-shy‐culture13 settings13 (raceways13 o tanks)13 Some13 practices13

are unique to a single facility13 or a couple of facilities (Table 6)13 Managers at each facility13

were asked to identify the biggest13 difficulty or constraint13 that13 they experience when13

growing-shy‐out juvenile13 razorback suckers13 at their13 respective13 location13 Space constraints13

water quality and disease problems were the main factors limiting production of razorback

suckers13 at these13 facilities13 (Table13 8) Calculated or reported growth rates from13 the literature

vary widely (Table 9) and range from13 02 to 18 mmday These growth rates indicate that

juvenile razorback suckers have a very high growth potential under optimal rearing

conditions13

Table13 4 Stocking13 densities13 for larvae13 and13 fry in ponds

$amp( )(+amp-( 01-2(3(4amp56( 4amp56(+amp-( 01-2782-( $amp () + --amp +amp0amp)+amp 12-3amp ( )+amp0amp+amp --amp +amp0amp)+amp 42556789amp8 ( +amp0ampgt+amp 3amp +amp0amp+amp A-BC-Damp (E + 3amp )+ F-6ltamp ) G+ 3amp G+

Table13 5 Rearing13 densities13 at intensive13 culture13 facilities13

$amp( )amp+(($-( $0( 12(3$+( 40((amp05( 67((amp05( 8$9(407$( $amp amp())amp++-$amp 0 1 0amp2amp1amp 3amp2amp4 0544

6amp())amp++-$amp 610 021 4amp2amp47amp 3amp2amp77amp 058 9$amplt+)amp 4amp())amp++-$amp 00 1 7amp2amp77amp 851amp2amp0amp 05

6amp())amp++-$amp 610 77amp2amp1amp 0amp2amp1amp 053

19

13

Table13 6 Rearing13 practices13 that are13 unique to13 specific rearing13 facilities13 $$amp( )$+-(amp$-(0(1-amp2034( $amp()amp+( -0$(12(33+(amp(amp134$53+(amp$amp3+(6amp+(

723(843(1$8(422(6amp+(42amp(4(423(19$43( 343( lt34$53(6amp+(6(4($03(amp4+94amp(842($1$1(63$$34(amp+(63626243( =amp+(gtamp94ampA( B3(1(1$+53+C3+(amp+(1$43(1(3D0$(1(amp443(amp+(amp443( 734231(amp( B3(1(193(44(1(34amp(amp(+49E(6amp+( -E3(F3+( G3amp(1(12(amp(H3(13$(4ampE(C(IJK($$amp( A( L43(+A3(4(6303amp4(63+4ampM(66$3D3amp4$(34amp(amp(6amp+(C((4amp3( L$$8(392(

B0$+3(

N43D(13+(4($0$(12M(amp+(639$53+($0$(12(+34( G3amp(12(amp(399$4amp(4+(938A(842($(2343+(843( N443D643+(3amp(12(amp(amp34(63amp(amp(423(O$+(G03( )amp+(3(134$53+(6(4(39364(1(1A(4(44(423D(amp((D3(amp4$(+34(

Table13 7 Types of feed used at razorback sucker13 hatcheries13 $amp ()amp+-amp0- $$)1amp23 45-amp)-$5)1amp23 $amp()amp+( -amp$amp+(amp+( -amp012$3+(amp+4(amp5215$(0+( 65ampamp7(85209(+2($1(87((15315lt=(+2(

+amp+amp(amp(55$5$2gt( 21( Aamp+(amp+( )amp+(012$3+(B29(5$05$95($$2(5amp+(

199524(amp5215$(0+( 65ampamp7(85209(+2($1(87(15315lt=(+2(amplt( 29gt(51($51(amp9(2(25=(C(DD(0+(

E15amp+(Famplt2amp( G1$5(lt1lt$51(25amp=( HIJKH(Dlt1amp(15315lt=(+2(I(C2(CH(+5gt( )11$gt($511(02+(15315lt=(+2(

$1(87(15315lt=(+2(D5$$(3(lt5$$gt(02+(gt( 6lt=(511B(

L15gt( G1$5(lt1lt$51(25amp=(Aamp+( amp+(

HIJKH(Dlt1amp(15315lt=(+2(I(C2(CH(+5gt( )11$gt($511(02+(15315lt=(+2(

$1(87(15315lt=(+2($1(87($B(amp=amp( 5$Damp(+2(

M$$B(5lt9(-5$+( NO515(G1$5(219( L2+1(15ltB5gt(Aamp+(5amp+( amp$amp+(amp+(

1amp(91D(amp5$(Pamplt5$amp4( 8gtlt$34(1$amp54(5amp+(5120lt5$( $5amp=2amp()amp+(012$3+(B29(5$05$95( $$2(5amp+(19952Q(amp12152( 1+lt2amp(

$1(87(15315lt=(+2($1(87(15315lt=(+2( $1(87(15315lt=(+2(

Table 8 Factors limiting production at major razorback sucker facilities

$amp( )amp+(-0+1((2$(0amp1ampamp(-34amp( $amp()amp+( -(01$2(34+(546(amp(0amp(01amp(541(13( -741( 803(3amp41amp4(9((+ltlt1amp4(03(amp(44amp(2=(4(

+ltlt3$4(4(2amp4amp(014(1gt13=(43=( 1amp+(amp34amp( 803(3amp41amp4(1$4+(4(541(A$4B(amp+(+$C+(

7Bamp($244amp(lt(1313$4amp(B42( D1B( E41(A$4B(01$2(3+(B(66(1amp(amp+(2ampamp(

Eamp41(420141(464(1A1($$(lt6(4((2C+(amp+1( 803(3amp41amp4(1$4+(4(541(A$4B(amp+(+$C+(7Bamp(

E$$5(36( 803(3amp41amp4F(15amp(lt6(4(amp31amp$B($11(gt( 1$4(amp(ampltlt3amp4(03(amp(44amp(lt1(amp5(lt6(

GC$+( 8221(420(3amp(4(6691A1amp(051((4(410$(+(4( 661(1amp+541(020amp(4(=0(0amp+(3$F(

20

13

$amp(

)+-amp)amp)

0$amp1

2)

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2)

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amp()

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2345

(6(

7-89

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lt=(gt

gt((8ampA(lt(gt

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B(AC1(Damp

8(E22

2(B81F(

Gamp(H(

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8(4lt

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gt(L+amp-8(B

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gt-(amp8(

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22J(

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23K=J

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235lt

(6(3(

V-9(=22Q9(

=2

2P=5

2(gtgt(8D3(Tamp

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(Q=5J

F234lt((Samp

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DS-amp(C-ampD

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D(ampD

(Mamp

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B8(J2

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(X-

DS-amp(C-ampD

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( 23J

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DS-amp(C-ampD

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Gamp

8amp(ampD(18S1

8amp(=2

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Yamp(Z+

(B-

DS-amp(C-ampD

( 23I(P(32lt(

0D

D(ampD

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8(=22

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N+-(B81(B8(BC

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Yamp(Z+

(B-

DS-amp(C-ampD

8( 3Q

G1

--(ampD(18S1

8amp(=2

2K(

22(gtgt(AC1(

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([(C (amp

-(52(W(1

(B(B-D

S-amp(C-ampD

8(M

gtS1

(S

ampD(H-D(

3K(6(

D

ampA(ampD(8gtamp

D8amp

(4lt

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-$D(S

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232K

lt(6(

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-(N(gt

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3

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0amp

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TampD

(9C(N(01

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7-89

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lt=(gt

gt((8ampA(lt(gt

amp18(

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(M1

235(6

V7X^7(444

+

A(

-ampA(amp(Samp

D8[(]amp-(X81

(M1 (

(23Qlt(6(

V7X^7(444(

+ A(

-ampA(amp(

C8(

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[(]amp-(X81

(M1 (

235J

(P(23I(6(

_8(44lt(

S

-(

([(amp(Samp

D8(=I

(gtgt(

(5I

(gtgt((

ampD(B(

8(8

8amp

(OA(

`(A-B(8(

235K

(P(23Jlt

(6(3(

0

-- (

ampD(^

(4

4lt(

5(gtgt(

(QJ2

(gtgt(amp(=(a(5

(gtamp

1(S D(--D

(C1

(gt

gt-(amp(

ZampD

amp1(Samp

D(V1(

23=J

lt(6(

OBB

((

-(=22

Q(

L+amp-(B81(b

K5(gt

gtc((8D((KKK

(S ((

V+-D(

235J

(R(6(

V7GZ(=2

2J(

7D(d=22

(gtgt(amp(F=((Samp

D(ampD(1+8D(eQ22

(gtgt(8U(gtamp

18(-(

fampamp

(Oamp

D(V1(

23Qlt

=(6(

OBB

((

-(=22

Q(

N+-(B81(8D

((=

522(S

((

ggt(H

+(

32J

(6(

0

-- (

445(

]--(8S

Camp

D(-+-(B81(

ggt(H

+(

3lt(6(3(

0

-- (

ampD(G(=22

5(

7D(8(=5(gtgt(-+(1D

(Q22

(gtgt(9(amp

D(B(8

gtgt (

Table9Reportedandcalculatedgrowthratesfromtheliterature

Calculatedgrow

thratesbasedon

informationprovidedinliterature

aApproximationsofmaximum

grow

thpotential(basedon

average13 maximum

sizesiffishreportedatharvest

21

13

General Information on Factors that Affect Fish Growth

Growth in fish is extremely variable and is impacted by many different

physiological and environmental factors Growth rates are known to change with size and

age sex season activity level density amount13 of living space quality and quantity of food

genetics and temperature (Brett 1979) Growth experiments conducted at different times

of year can result in growth rates that are not comparable As fish become larger their

physiological13 potential to grow decreases making determination of growth rate dependent

on the size of the starting fish and the length of the experiment (Busacker et al 1990)

Genetic factors also have great potential to influence growth rate Some species have

strains13 and13 races13 that display vastly different growth potentials (Reinitz et al 1979) All of

these factors combine to make assessment of the individual factors controlling fish growth

difficult13

Water temperature is probably the most important variable affecting growth rate13

All of the basic functions that affect growth such as feeding digestion and metabolism are

temperature-shy‐dependent13 Growth13 is inseparably13 tied13 to13 bioenergetics13 and13 therefore13 also13

tightly tied to temperature When temperatures are below optimum daily temperature

fluctuations can stimulate growth Photoperiod is also commonly linked to water

temperature and can influence growth rates in fish (reviewed in Brett 1979)

Fish density13 is known to13 affect growth13 and13 can alter13 growth13 rates13 in several ways13

Fish that exhibit strong territorial behaviors13 or natural schooling tendencies13 will

experience reduced growth if densities are too high or too low (Brett 1979) Dominance

hierarchies where some fish feed more aggressively than others can also lead to high

variability13 in growth13 rates13 (Koebele13 1985) Crowded13 conditions13 also13 cause physical

interference13 between13 fish and13 poor water13 quality13 which13 reduces13 growth13 (Busacker13 et al13

1990) The effects of fish numbers space and feeding opportunity are frequently correlated13

and often13 difficult13 to distinguish (Brett13 1979)13

It is impossible to study the effects of environmental factors on growth without also

evaluating feed rations (Brett 1979) Amount of food quality of the diet particle size

number of feedings per day and time of feeding have all been shown to affect growth

(Busacker et al 1990) In controlled laboratory studies food is usually fed ad libitum13

22

13

(constantly available) and other variables are altered to assess impacts of environmental

factors13 on growth13 These studies13 are13 usually13 conducted13 in tanks13 or raceways13 because13

researchers must verify that food is constantly available to the fish which is difficult to do

in large pond environments where the fish and the bottom13 are often not visible (Busacker13

et al13 1990)

Specific Information13 o Razorback13 Sucker13 Growth

Variable13 growth

Growth in razorback suckers is naturally highly variable and may be a function of

their evolutionary history (USFWS13 2002)13 Minckley (1983) speculated that13 wide size

variation in a single cohort of razorback suckers may be adaptive with fast-shy‐growing13 fish

that13 reproduce at a young13 age surviving13 better in13 high discharge years and slow-shy‐growing13

smaller fish surviving better during drought periods This highly variable growth rate

makes rearing razorback suckers in a production setting difficult because fish from13 a single

cohort do not reach the target stocking size simultaneously One of the major tasks for

aquaculture is to maximize both individual growth and total production13 (Gerking13 1978)13

This becomes more difficult when the species being cultured exhibits highly variable

growth13 rates13 because of genetic influences as is the case with razorback13 suckers13

Razorback13 sucker growth13 is typically very13 rapid13 during13 the first13 year of life13 and then13

declines with age First year growth can be as low as 50 mm and as high as 350 mm (Valdez

et al13 1982 Minckley13 1983 Mueller13 1995) Razorback sucker13 grow rapidly13 for

approximately the first five or six years of life and then growth slows13 (McCarthy13 and13

Minckely 198713 Tyus 199813 Minckley et13 al 1991)13 Growth of older individuals in13 extant13 wild

populations is very13 low (Minckley 198313 Tyus 198813 Modde13 et al 1996)13 Wild growth13 rates

for mature adult fish in Lake Mohave based on PIT tag recaptures were often too small to

be accurately measured for both males and females over the time period of 1987-shy‐199713

(Marsh and Pacey 1998) This information suggest it will take substantially longer to rear

fish to13 increasingly13 larger13 stocking13 sizes (40013 ndash 500 mm TL) than it did to reach the target

size of 300 mm TL

Growth in ponds

23

13

One of the main strategies for maintaining genetic refugia and self-shy‐sustaining13

populations of razorback13 sucker in the lower Colorado13 River basin13 is to rear razorback13

sucker13 larvae13 in production13 ponds until they13 are13 a suitable13 size for stocking13 (USFWS13 2004)

Pond culture has proven useful to promote rapid growth of juvenile razorback suckers

(Kaeding and Osmundson 1989) Marsh (1994) reported that growth rates of razorback

suckers13 reared13 in golf-shy‐course13 ponds exceeded13 the13 best growth13 rates13 obtained13 under

intensive13 culture13 conditions13 at federal hatcheries13 especially13 during the13 first several years13

of life Growth rates in these semi-shy‐natural ponds are also comparable to estimated growth

rates13 of juvenile13 wild13 fish (McCarthy13 and13 Minckley13 1987) Modde13 and13 Haines13 (2005)

reported13 the13 greatest growth13 rates13 in the13 largest and13 deepest floodplains13 with13 the13 greatest

amount of submergent vegetation but excellent growth and survival of fish in a grow-shy‐out

pond is of little value if there is not an efficient way to collect the fish from13 the pond

(Kaeding and Osmundson 1989)

Temperature13

Bulkley and Pimentel (1983) used shuttle boxes in the laboratory to determine a

temperature preference13 for razorback suckers13 of 23-shy‐24degC13 In13 their13 studies13 razorback

suckers were found to avoid temperatures below 118 degC or above 286 degC Razorback

suckers at Bubbling Ponds Hatchery are more active in the spring and feed better as

photoperiod increases even prior to water temperatures rising (Frank Agygos personal

communication) Table 3 briefly summarizes water temperature data from13 each facility

Detailed seasonal water temperature profiles are not currently available for many

razorback grow-shy‐out sites13

Density13

Extensive studies have been conducted on commercially important species to

evaluate stocking densities and feeding rates that maximize production For these species

controlled experiments under laboratory conditions have established relationships

between temperature density and feed ration on growth (Brett 1979) but this information

is sporadic13 or non-shy‐existent for razorback suckers13 (Bays13 et al13 2005) Fish culturists13 with13

24

13

experience13 rearing13 razorback suckers13 typically13 have13 target stocking13 densities13 that13 they use

(Tables13 4 -shy‐ 5) These stocking densities have largely been determined over time by trial

and error These approximate stocking densities provide a good starting point for more

controlled13 types13 of replicated13 pond studies13

Feed ration

Razorback13 suckers are currently13 being13 fed a wide variety13 of prepared diets (Table 7)

that range from13 a slow-shy‐sinking salmon feed manufactured by Silver Cupreg to a spirulina

and krill-shy‐enhanced catfish feed made by Rangenreg Most locations are feeding 20 ndash 50

body13 weight per13 day13 Methods13 for culture13 of razorback sucker13 larvae13 in intensive13 settings13 at

fish hatcheries are well documented (Figiel 2005) and various larval fish diets have been

evaluated13 (Tyus and13 Severson 1990 Severson et al13 1992) but no standardized13 procedures

are used for feeding13 larval13 fish in13 intensive settings13

Razorback sucker larvae are also effectively reared in pond environments using

natural foods supplemented with larval fish diets and survival is high when no predators

are present13 (Mueller 2006)13 Growth rates for larval13 and early juvenile razorback13 suckers

may increase with pond fertilization Diet and physiological studies on wild razorback

suckers indicate that they feed on plankton as well as benthic organisms during their entire

life (Marsh 1987) Artificially fertilizing ponds may greatly increase production capacity

and growth rates for razorback13 sucker (Papoulias and Minckley13 1992) and warrants

further13 investigation13

Handling stress

Handling stress13 has13 been shown to13 influence growth13 rates13 Paukert13 et al (2005)

found that growth of bonytail chub was reduced by 26when compared with controls

after being13 repeatedly13 captured and handled in13 hoop13 nets13 Handling13 effects are likely13 to be

similar for razorback suckers that are repeatedly13 captured and sorted in13 a hatchery13 setting13

Razorback suckers that are handled at Willow Beach National Fish Hatchery will commonly

not eat for two weeks after handling (John Scott personal communication) This creates a

difficult situation13 for production13 facilities because13 fish13 need to be sorted to ensure13 large13

25

13

aggressive fish do not interfere with growth of smaller individuals but frequent handling

and sorting13 causes stress related reductions in13 growth13

Measuring Growth in Captive Fish

Weight is the traditional measure used to estimate growth or production in

aquaculture settings13 Groups of fish are typically13 weighed and an average individual13 weight13

is computed (Busacker et al 1990) Although this method is often logistically the easiest it

may not be the most informative for species with highly variable growth rates like

razorback suckers especially when target lengths must be reached before fish can be

stocked Weight can also be highly influenced by things like stomach fullness or

development of gonads (Busacker et al 1990) Condition factor or relative weight can also

be used to assess growth of fish but these tools may be more robust predictors of fecundity

than of growth (Anderson and Neuman 1996) For some species sexes need to be

distinguished because males and females may differ in morphology (Anderson and

Neumann 1996) Mueller (2006) analyzed growth rates based on PIT tag recaptures of 86

razorback suckers13 in High13 Levee Pond13 and13 found13 that differences13 in growth13 do not appear13

to occur until fish are over 450 mm TL at which time growth rate in males slows while

females continue to grow at a slightly higher rate This would indicate that sex may not be

an important factor to consider when examining growth rates unless the target grow-shy‐out

size is above 450 mm TL

The best measures of growth are often determined from13 the length and weight of

individuals rather than from13 groups of fish (Anderson and Nuemannn 1996) because

individual growth rates give better estimates of confidence and variance (Busacker et13 al

1990) Length frequency analysis or recapture of previously marked individuals of a known

size is likely to yield the most useful information for razorback sucker growth The success

of any of these methods depends on proper sampling procedures that are representative of

the population as a whole (Busacker et al 1990) Sampling methods that are known to be

size-shy‐biased such as trammel nets (Mueller et al 2004) or cast nets should not be used when

trying to measure growth rates13

26

13

Conclusions

For razorback sucker survival is largely associated with stocking size Additional

focused13 research13 is therefore13 needed to13 identify13 ways13 to13 increase13 growth13 rates13 of captive-shy‐

reared13 razorback sucker Growth13 rate13 in fish is controlled13 by many factors including fish

size and age temperature density and feed ration which can all be highly correlated

Growth of razorback suckers is also inherently variable which makes the task of identifying

the key factors that13 affect13 growth in13 captivity even more difficult The focus at most

razorback rearing facilities13 is production so the13 types13 of data that are13 collected13 are13 often

insufficient for detailed13 evaluations13 of individual rearing13 practices13 on growth13 Surveys of

existing13 razorback sucker13 rearing facilities indicate that culture methods vary widely and

the types of growth data13 that13 are collected are not13 standardized13 Replicated studies with

detailed information on rearing location water temperature initial stocking size stocking

density and the sizes of all fish at harvest are needed in order to compare the effects of

individual rearing practices on growth This type of research will ultimately provide both

time and cost-shy‐savings to production facilities by reducing the amount of time necessary13 for

razorback sucker to reach stocking size improving overall production efficiency

Optimum13 rearing densities for razorback sucker larvae and juveniles remain to be

determined Current stocking densities will be very useful as starting point for more

detailed studies and although optimum13 rearing densities are likely to be site-shy‐specific13

replicated studies on density will provide a valuable reference for hatchery managers

Frequency13 of sorting is another13 area that needs13 further13 research Frequent

handling13 and13 sorting13 can13 cause13 stress-shy‐related13 reductions13 in growth but not sorting can

create dominance hierarchies that further reduce growth rates of subordinate individuals

The effects13 of sorting13 on overall fish growth13 in both13 pond and13 intensive13 culture13

environments warrant further investigation Research techniques for these types of

experiments are well understood and typically utilize a matrix of replicate ponds per

variable (Bays et al 2005) In every case accurate and complete records of sampling

procedures and data collection are needed in order to interpret data and make inferences

about13 growth rates (Busacker et13 al 1990)13

27

13

Additional research is also needed to evaluate long-shy‐term13 survival of stocked fish

reared in ponds compared to fish13 reared13 in intensive13 culture13 facilities13 Exercise13

conditioning13 and predator-shy‐recognition training may also increase survival of stocked fish

and be more economically feasible than rearing fish to increasingly larger sizes prior to

stocking13 The success13 of traditional fish hatchery programs is measured largely by the

number of fish stocked but hatchery programs for endangered species must measure

success in terms of long-shy‐term13 survival and species recovery (Brannon 1993 Anders 1998)

A specific list of research recommendations follows

Specific Research13 Recommendations13

bull Use replicated studies13 to establish optimum stocking13 densities13 for ponds13 and

tanks13 that can be used as13 a starting13 point for site specific refinement

bull Determine if sortinggrading13 improves13 overall growth rates13 in both ponds13 and

intensive culture facilities13

bull Investigate the use of artificial fertilizers13 to improve growth of both juvenile

and adult razorback suckers13 in ponds13

bull Determine if the razorback sucker diet gives13 better growth rates13 than cheaper

catfish or salmon feeds

bull Evaluate growth rates13 and production potential of new intensive culture

methods13 such as13 large circular tanks13

bull Evaluate13 long-shy‐term survival of fish produced from raceways13 and circular tanks13

compared to fish reared in ponds13

bull Evaluate more effective means13 of treating13 fish diseases13

bull Evaluate factors13 other than size that may increase post-shy‐stocking13 survival such

as13 exercise conditioning13 predator recognition training or rearing13 under more

natural settings13

28

13

II The Effect of Disease Treatments on Razorback Sucker

Growth

Section13 SummaryFormalin copper sulfate potassium permanganate and13 salt are all chemicals commonly13 used13 to13 treat13 Ichthyophthirius multifiliis outbreaks in captive razorback sucker (Xyrauchen13 texanus) Weexposed 190 juvenile13 razorback suckers (127 ndash 26 mm TL) to13 5 5-shy‐day treatments with13 each13 chemical to evaluate the effects13 these chemicals13 may have on growth Fish grew an average of23513 mm TL13 during the month13 study period Fish treated with formalin grew on average13 29mm TL (03 mmday) while fish treated with copper had the lowest growth averaging 20 mmTL (021 mmday) No significant differences in13 growth were observed among fish treatedwith any of the chemicals compared to untreated fish (pgt005) Reductions in growth13 as aresult of repeated chemical treatments are not likely the cause of differences in growth ratesamong13 facilities that raise razorback suckers Repeated chemical treatments may13 have otherimpacts to overall13 fitness or long-shy‐term survival but13 these effects were not13 evident13 in our study

29

13

Introduction

Preservation13 of razorback sucker13 (Xyrauchen texanus) currently13 depends on captive13

rearing and stocking programs until permanent solutions to factors that prevent wild13

recruitment are found Low survival of stocked razorback suckers (Brooks 1986 Marsh

and Brooks 198913 Marsh and Pacey13 2005) has caused target13 sizes for stocked fish to

steadily increase in efforts to reduce predation mortality (Marsh et al 2005 Schooley and

Marsh 2007) Rearing fish to larger sizes at hatcheries comes with increased costs and

creates the need to evaluate husbandry and rearing practices that may affect fish growth

Formalin copper sulfate potassium13 permanganate and salt are all chemicals

commonly used at razorback sucker rearing facilities to treat outbreaks of the protozoan

parasite13 Ichthyophthirius multifiliis ldquoIchrdquo is one of the most pathenogenic diseases of

cultured13 freshwater13 fishes (Matthews13 2005) and causes large13 losses in captive13 populations13

of endangered razorback sucker Each of these chemicals used to treat Ich only kill the free-shy‐

swimming life stage of the parasite13 requiring13 repeated doses over several13 days depending13

on water temperature These chemicals treatments are needed to prevent loss as a result

of disease outbreaks but the cumulative effects repeated disease treatments have on

growth13 are13 unknown

Copper13 sulfate13 has13 been shown to13 significantly13 reduce13 growth13 of channel catfish13 in

production13 ponds (Rabago-shy‐Castro13 2006) but it is unknown whether13 razorback suckers13

experience similar reduced growth following copper treatment Quantifying the impacts of

disease treatments on growth will help to interpret the wide differences in growth rates

observed13 at various13 razorback sucker13 production13 facilities13 throughout the13 southwest

(Ward et al 2007) If one chemical is found to have less detrimental impacts on growth

than another then it may be preferred for use as a disease treatment We evaluated growth

rates13 of razorback suckers13 under13 replicated13 and13 controlled13 conditions13 to13 assess13 effects13 of

repeated formalin copper sulfate and potassium permanganate and salt treatments on

growth13

Methods

We captured 190 juvenile razorback suckers from13 ponds at Bubbling Ponds Fish

Hatchery AZ using hoop nets or cast nets All fish were of the same age class and

30

13

averaged 179 mm total length (TL) (range13 = 127 ndash 262 mm TL)13 These fish were13 offspring13

of captive13 razorback sucker13 broodstock held13 at Dexter13 National13 Fish Hatchery13 NM13 (2007

year class) All fish were tagged with passive integrated transponder (PIT) tags and

quarantined for one month prior to the experiment to allow fish to recover from13 tagging

and become accustomed to being held in circular tanks

At the beginning of the study all fish were weighed measured and scanned for

individual tag numbers with 19 randomly selected fish placed into each13 of 10 8-shy‐foot

diameter circular tanks (Figure 2)13 Each13 tank contained13 two13 airstones13 and13 an13 individual

biofilter with a recirculating water pump (31 litersminute) that had been operating for

at least 1 month prior to the experiment to allow bacterial colonies to become

established Two tanks were designated as a control and did not receive any chemical

treatments while the other eight tanks received formalin copper sulfate potassium13

permanganate or salt treatments at two week intervals (two tanks per chemical

treatment) Formalin copper sulfate and potassium13 permanganate were treated at 1 part

per million (ppm) and salt was applied at 30 parts per thousand (ppt) These treatment

rates are commonly used to treat13 razorback13 suckers for ich at Bubbling13 Ponds Fish13

hatchery (Frank Agygos personal communication)

Figure 213 Photo ofexperimental tankswith individualbiofilters and aeration

31

13

Each treatment consisted of a series of doses applied on Wednesday Thursday and

Friday with a 90water change between each dose Biofilters were removed from13 all

tanks and held in a separate holding facility during treatments and then replaced on the

Monday following treatments after a 90water change This schedule allowed fish to be

exposed to chemical treatments for 5 consecutive days without water quality deteriorating

This 5-shy‐day chemical treatment was repeated every two weeks from13 July to October (97

days)13 for a total of 5 5-shy‐day treatments Water temperature in the treatment tanks ranged

from13 13degC (55degF) to 32degC (91degF)

Fish were fed a fixed ration of commercial razorback diet (Silvercup 4mm13 pellet)

once daily13 (2 percent body13 weight per day13 as calculated13 by13 average initial fish weight)13

At the end of the experiment all fish were again weighed measured and scanned for

individual tag numbers Growth of fish in each treatment group was compared using

analysis of variance (ANOVA) Any mortalities13 that occurred during the13 study13 were13

replaced with previously quarantined fish of equivalent size to maintain equal densities in

each13 tank13 but growth13 data was13 only13 recorded for fish which13 survived13 the13 entire13

experiment

Results

Fish at the13 start of the experiment averaged 179 mm TL (Range13 = 127 ndash 262 mm)

with no significant differences in fish length among treatment groups (F(4189) = 00183 p

gt 0999 ANOVA) On average fish grew 235 mm TL (024 mmday) during the 3 month

study13 Fish in tanks13 treated with formalin had the highest growth averaging 29 mm TL (03

mmday) while fish in tanks treated with copper had the lowest growth averaging 20 mm

TL (021 mmday) Fish in the control tanks averaged 213 mm TL in growth (022

mmday) (Figure13 3)13 Formalin-shy‐treated fish grew13 significantly faster than13 any other

treatment group but no13 significant differences in growth13 in length13 or weight were13

observed among fish treated with any of the chemicals compared to untreated (control)

fish (pgt005 ANOVA)

32

13

Figure 313 Average growthof razorback suckersexposed to a series of 5 5-shy‐day chemical treatmentsover a 97-shy‐day13 periodError bars representstandard error

Discussion13

Growth13 rates13 observed13 in our study13 (021 ndash 03 mmday) are low compared to those

reported13 in other13 studies13 of razorback sucker13 growth13 (0213 ndash 18 mmday) (Ward et al

2007) Using recirculating water systems for our study required filters to be removed and

replaced during treatments Stress to fish caused by removing and replacing filters within

the tanks as well as repeated water changes may have led to overall higher stress and

reduced growth rates compared to those reported for unconfined fish Growth in fish is

highly variable and is affected by many different physiological and environmental factors

including fish size density temperature amount of space and food (Brett 1979) We

strived to control each of these factors but other factors may have also influenced growth

in our experimental tanks During mid-shy‐summer water temperatures in the treatment

tanks reached 32degC (91degF) At these warm13 temperatures fish are very susceptible to

bacterial13 infections13 The slightly higher growth exhibited by fish in the formalin and

potassium13 permanganate treatments may have been the result of these two chemicals

33

13

being effective at controlling bacterial infections The differences in growth we measured

among treatment groups were not statistically significant and do not appear13 biologically13

meaningful during the relatively short duration of this study (97 days) although the

cumulative effects of slightly reduced growth could be biologically meaningful over longer

time frames

Reductions in growth13 as a result13 o repeated chemical treatments are not likely the

cause of differences in growth rates among facilities that raise razorback suckers

Repeated chemical treatments may have other impacts to overall fitness or long-shy‐term13

survival but these13 effects13 were13 not evident in our study It is more likely that the parasite

outbreaks themselves are the cause of different growth rates among razorback rearing

facilities rather than the chemical treatments used to treat the parasites We recommend

that hatchery managers continue to use the chemicals that are most effective at controlling

ldquoIchrdquo13 at their individual13 facilities

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower Colorado Rive Multi-shy‐species13

Conservation Plan under Work Task C10 We thank Ty Wolters and Tom13 Burke for their

support of this research and Frank Agygos and Dave Billingsly of the Bubbling Ponds Fish

Hatchery13 for their13 technical assistance13 and13 help with13 collecting13 fish

34

13

III13 Razorback Growth Rates at Bubbling Ponds ndash 2009-shy‐2011

Section13 SummaryExperimental studies at Bubbling Ponds Fish Hatchery AZ have strived to understand

factors that affect razorback sucker growth in captivity and identify ways to improve growthrates and maximize size at release Rather than performing experimental studies that wouldrequire major13 rearrangement (and likely reduced production)13 of hatchery operations our13 studies13 used normal variation in production techniques13 and practices13 to isolate factors13 thatmay modify growth rates

Our initial work identified razorback13 growth rates in13 lined ponds at standard fishdensity as 026 to13 028mmday (789 to 843 mmmonth) No significant differences in growthrate were observed among fish that had been in the pond only during the winter13 periodcompared to fish that had been in the pond the entire year indicating that water temperatures13 at Bubbling Ponds are high enough to allow fish to incorporate feed effectively year-shy‐roundHowever these growth rates are lower than most values reported from the literature fromnatural or semi-shy‐natural pond environments No significant differences in13 growth rate wereobserved13 between large and13 small fish13 within the 150 ndash 29 mm TL13 size range Additional worksuggests13 that razorback suckers13 tagged at over 300 mm TL had reduced growth rates (024mmday 73 mmmonth) as would be expected according to a typical Von13 Bertalanfy growthcurve although growth rates13 were only slightly less13 than the average growth rate for thehatchery (027513 mmday 82513 mmmonth)

Sorting13 to13 separate small fish from large fish after the first year of growth is practicedesigned13 to allow smaller fish to ldquocatch uprdquo to larger fish We found that13 this technique doesappear to13 improve growth rates of smaller fish Growth rates of sorted small razorback suckers(029 mmday 87mmmonth)13 were equal to that13 of larger13 fish (028 mmday 8413 mmmonth)indicating that sorting may have helped to offset their original slower growth trajectory

Bubbling Ponds Fish Hatchery grows razorbacks in 6 long deep ponds lined with heavyplastic 2 long deep13 earthen13 (unlined) ponds and three wide shallow earthen ponds The wideshallow ponds13 have historically produced very large fish at low density but have been found tomaintain much lower fish numbers than deeper ponds We found13 that growth13 rates ofrazorbacks kept at high density (4-shy‐700013 fish)13 in a wide shallow pond grew extremely slowly(024 mmday 726 mmmonth) This growth rate is among the slowest of any fish over theyears of our study and demonstrates that13 though the large ponds may produce large fish at lowdensity13 they are unable to overcome high13 fish13 densities

Finally one of the major factors influencing13 fish13 growth13 in hatcheries is disease onemajor summer-shy‐time disease at13 Bubbling Ponds is the ectoparasite Ich (Ichthiopthirusmultifiliis) To investigate the impact Ich has on razorback growth we eradicated fish from thespring and water conveyance ditch that supplies13 water to the hatchery using Rotenone This13 restoration effort was fairly short-shy‐lived (Ich returned to the hatchery within four months) but

35

13

growth13 rates of fish13 reared for four months without Ich present (031 mmday 92 mmmonth)were significantly higher than the following 8 months of growth for those same fish (022mmday 65 mmmonth) This disease-shy‐free growth rate is in fact faster than any13 otherprevious growth rates observed at the hatchery in our study

We conclude that growth rates at the Bubbling Ponds Fish Hatchery are likely as highas possible given the pond densities required to13 meet production goals and the Ich-shy‐infestedwater13 that feeds the facility Sorting practices are successful in helping as many fish as possiblereach stocking length as fast as possible Unlined ponds may be able to grow large fish at lowdensities but whatever factors allow for that growth13 are not able13 to overcome13 high fish densityThus the large lower ponds at Bubbling Ponds may be better utilized via renovation to13 deepenand line them

Disease is the most important factor limiting growth as may be expected to be the caseat many13 hatcheries While the spring renovation was not13 a complete success13 the dramaticreduction of fish populations in that habitat was enough to dramatically13 reduce13 the13 occurrenceof Ich at the hatchery13 Such open spring13 systems feeding a hatchery are a misfortune that canbe expected to transmit disease so we suggest that renovating the spring again to combat13 IchImproved techniques to divert water from13 the springs and more throuough treatment ofstream-shy‐side vegetation may improve the success of chemical treatment Successful renovationwould likely both improve growth rates and reduce chemical costs associated with treating Ichoutbreaks Even13 if complete renovation13 is impossible or impractical an13 effort to reduceinvasive fish density in the springs13 which act a vector for the parasite(and thereby reduce thelikelihood of13 Ich being transmitted into ponds) may still13 show dramatic improvements

36

13

Introduction

Conservation efforts13 for razorback sucker13 (Xyrauchen texanus)13 currently13 depend on

captive rearing and stocking programs Low survival of stocked razorback suckers (Brooks

1986 Marsh13 and13 Brooks13 1989 Marsh13 and13 Pacey13 2005) has13 caused13 target sizes for stocked13

fish to steadily increase in efforts to reduce predation mortality13 (Marsh13 et al13 2005

Schooley and Marsh 2007) Rearing fish to larger sizes at hatcheries comes with increased

costs and creates the need to evaluate husbandry and rearing practices that may affect fish

growth13 We evaluated growth13 rates13 of individual razorback suckers13 in ponds13 at Bubbling

Ponds Fish Hatchery13 using Passive Integrated13 Transponder (PIT) tags13 to13 obtain13 precise

growth information for individual fish so that valid comparisons of growth rates as related

to rearing practices can be made

Due to the critical nature of the razorback sucker stocking program we did not

design experimental studies that would require major rearrangement and potentially

reduce production of hatchery operations Instead our studies used normal variation in

production techniques and practices to isolate factors that may modify growth rates

Though this methodology dramatically limits replication and may limit our ability to

directly13 attribute13 differences in growth13 rates13 to13 the13 variables13 we13 investigate13 we13 were13 able13

to accomplish research goals without altering hatchery operations or impacting

production

From13 2009 through 2011 we conducted a series of observational13 growth13 studies to

determine growth rates of individual razorbacks at Bubbling Ponds The first set of

experiments included13 identifying13 growth13 rates13 in lined13 and13 unlined13 ponds determining

growth13 rates13 of fish at different13 sizes13 in13 relation13 to sorting13 practices and monitoring

razorback growth rates after removing the source of the ectoparasite13 Ich (Ichthiopthirus

multifiliis) from13 the hatchery water source13

Razorback growth rate in lined ponds

Our first growth study documented individual growth rates at normal density in 11

million gallon lined ponds13 over two13 years13 This is the standard13 grow-shy‐out process for

razorbacks13 at Bubbling Ponds We monitored growth of fish for a variety13 of sizes and13 the13

37

13

amount of time in a pond during the growing season These13 data give a snapshot of growth13

rates13 at the13 facility13 and13 provide13 the basis for comparisons throughout our study

Growth rate13 in an unlined pond

In addition13 to 6 ponds lined with heavy plastic13 sheeting13 Bubbling Ponds Fish13

Hatchery maintains two narrow and deep (same dimensions as lined ponds13 Figure13 4)13 and13

three large13 shallow unlined ponds These earthen13 ponds typically have vegetation and

associated aquatic invertebrates that may better simulate natural environments by

providing cover and improved food diversity or quality Therefore these unlined ponds

may be expected to produce higher growth rates and potentially improved survival that is

more similar to growth rates observed in more natural grow-shy‐out facilities13 Historically13 the13

large13 shallow13 ponds have produced very large fish when13 utilized at low13 fish density13 The

narrow13 deep earthen13 ponds are13 used to grow13 fry13 at high density in their first13 year of life

The major downside to unlined ponds is the difficulty in harvesting fish where a lined

pond might take 8-shy‐1013 people13 a half13 day13 to13 harvest13 lined13 ponds13 require13 intensive13 weeding13

to allow seines to be pulled and therefore require many more personnel-shy‐hours13 In addition13

to harvest challenges the shallow earthen ponds tend to suffer from13 dissolved oxygen

crashes during the summer Unlined ponds also may maintain higher13 populations13 of non-shy‐

target species such as bluegill sunfish mosquito fish and bullfrog tadpoles We measured

growth rates of suckers in a large shallow earthen pond for comparison to growth in lined

ponds13

Figure13 4 Lined13 and13 earthen ponds13 of similar dimensions (approx 1000000 gallons first

and second panels) and a large13 shallow13 earthen13 pond (third panel)

38

13

Effect of sorting on growth

Razorback13 suckers13 are13 currently13 sorted13 after their first13 year of growth13 They are13

typically removed from13 one of the13 upper earthen13 ponds and13 split into13 two13 lined13 ponds for

subsequent grow-shy‐out13 The larger13 fish (gt approximately 140 mm) are placed into one pond

and the smaller individuals in another It is possible that the larger fish were more

aggressive or adept13 at taking food so this sorting process is intended to allow smaller fish

to improve their growth rate

Effect of Ich on razorback sucker growth rates

We13 evaluated13 growth13 rates13 of razorback sucker13 in the13 presence13 and absence of the

ectoparasite13 Ich (Ichthiopthirus multifiliis) Ich outbreaks can occur in wild populations13 but

hatcheries13 have13 proven excellent locations13 for Ich because13 of very high fish densities13 which13

facilitate13 the13 transfer13 of Ich13 between13 fish This common fish parasite causes direct mortality13

to razorback13 suckers as well13 as secondary bacterial13 infections13

The open spring and13 ditch13 which13 provides water to the Bubbling13 Ponds Hatchery

has long13 been infested with mosquitofish (Gambusia affinis) that harbor13 the13 Ich parasite13

and allow13 it13 to enter the hatchery with incoming13 water13 The solution13 to13 the13 Ich problem13

was to remove the mosquitofish host using13 Rotenone Razorback13 sucker growth13 rates were13

then tracked in13 the absence of this parasite for 4 months and compared with growth rates

after Ich returned to the pond and from13 previous years

Methods

Razorback growth rate in lined ponds

On May 14 2008 141 razorback suckers were tagged with 12 mm PIT tags (1342

kHz) and placed in Pond 3 (approximately 1100000 gallons13 Figure13 4)13 at Bubbling13 Ponds

Fish Hatchery Fifty-shy‐three of these tags were recovered two months later when a large

Ichthyophthirius multifilis (Ich) outbreak killed many fish in the pond On October 15 2008

an additional13 145 PIT tagged13 fish were13 also placed into Pond13 3 On13 May13 14 2009 Pond13 3

was harvested and a total13 of 141 PIT tagged fish were recovered13 Of the tagged fish13 26 fish

had13 been13 in the13 pond since May13 of 2008 (378 days13 o growth) and 115 had been13 in13 the

39

13 40

pond since October13 15 2008 (211 days13 of growth) Numbers of fish in Pond 3 after the Ich

outbreak and for the majority of the period of growth were between 3 000 and 4000 fish

A Hobotempreg temperature13 logger13 was13 also13 installed13 in Pond 3 one meter below the water

surface13 near13 the13 outflow and13 recorded water temperature every 3 hours to allow analysis

of the effects of water temperature on growth rate (Figure13 5) This Hobotemp data is

representative of other pond temperatures throughout this study

In a second experiment 210 adult13 razorback suckers13 were13 PIT tagged13 on13 May 14

2009 and13 placed13 into13 Pond13 3 upper to13 evaluate13 growth13 rates13 of larger13 razorback suckers13 at

Bubbling13 Ponds Hatchery13 under current13 rearing13 conditions13 Size of these fish at tagging13

was (mean = 285 mm range = 205 ndash 396 mm) These fish remained in the pond for 257

days and were harvested on Jan 25 2010 to provide information on growth rates of larger

razorback suckers13 under13 current rearing conditions

Figure 513 Temperatures (degC) inrearing pond at BubblingPonds Hatchery from July toSept 2009 (top graph)13 andfrom Nov to Dec 2009 (Lowergraph) Temperaturesrecorded with a Hobotempregremote data logger13 every 3hours

13

Growth rate13 in an unlined pond

To document razorback sucker growth in earthen ponds we introduced13 225 tagged13

razorback suckers13 into13 Pond13 1 lower13 (Figure 4) in February 3 2010 Additional tagged fish

from13 other studies were added to the pond throughout the growing season and the density

of 1 lower reached a maximum13 of nearly 7000 fish in early summer 2010 Density was

reduced to approximately 6000 fish by capturing fish with hoop nets on June 3 2010 54 of

these fish were tagged fish and returned to 1 lower after being weighed and measured The

pond was harvested on January13 2713 2011 and a total13 of 254 tagged fish out13 of 4296 fish

total were removed from13 the pond The pond was harvested on January 27 2011 (358 days13

of growth) and the tagged fish were weighed and measured Total number of razorbacks in

the pond at harvest13 was 4296

Effect of sorting practices on growth rates

On March 1113 200913 Pond13 5 upper was13 harvested13 and13 split into13 two13 separate13 groups

Two hundred of the smaller fish (average size = 122 mm TL) were PIT tagged and placed

into13 Pond13 7 upper and13 200 of the13 larger13 fish (average = 160 mm TL) were PIT tagged and

placed int Pond13 8 upper Density13 in Pond13 7 was13 4500 fish and13 in Pond13 8 there13 were13 6500

fish These ponds were then harvested after 1 year and growth rates were compared to

give information on the effects of current sorting practices Hobotempreg temperature

loggers were installed in13 Ponds 7 and13 8 during13 the13 grow-shy‐out period with13 water13

temperature recorded every 2 hours13 (Figure13 6)

Effect of Ich on razorback sucker growth rates

Bubbling Ponds spring was treated with Rotenone (CFT Legumine 5) at a

concentration of 2 ppm13 to remove all mosquitofish from13 the spring The treatment

consisted of two treatments 6 hours in duration on two consecutive days (April 12 -shy‐ 13)

using13 drip13 stations13 and13 backpack sprayers13 followed13 by13 an13 additional 6 hours13 of

detoxification using sodium13 permanganate Although 12 mosquitofish were captured in the

spring pond the week following the treatments subsequent minnow trapping (20 traps

checked13 daily13 for 3 weeks) did not capture any additional fish until August 11 2010 when

41

13

juvenile mosquitofish were again detected in the spring pond Minnow traps have

subsequently been set daily with several hundred individuals removed To evaluate if Ich

was also again present in the spring we captured 15 mosquitofish from13 the spring pond on

three separate days and placed them13 in an aquaria at 25 degC with 5 longfin dace known to be

free of Ich These fish were monitored for 2 weeks with no signs of Ich developing This

indicates that even though mosquitofish have returned to the spring pond the parasite is no

longer present13 although how13 long13 this condition13 will13 persist13 is unknown13

On May 1113 201013 200 juvenile razorback13 suckers were harvested out13 of Pond 5

upper (2009 year Class from13 Dexter National Fish Hatchery) and were PIT tagged and

placed into Pond 8 to evaluate if growth rates at bubbling ponds hatchery have improved

following the renovation of the spring and the removal of the Ich parasite Unfortunately13

on Sept13 8 2010 Ich was13 again13 detected13 in Pond 8 and the pond was immediately seined

and 74 tagged fish were measured to obtain growth information for the 4-shy‐month period

during13 which13 the13 pond13 was13 Ich-shy‐free13

Figure13 6 Temperatures (degC) in rearingponds 7 and 8 at Bubbling Ponds Hatchery13 from March 2009 ndash March 201013 pond 7(top13 graph)13 and13 pond 8 (Lower13 graph)13 Temperatures recorded with a Hobotempregremote data logger every 3 hours

42

13

Results

Growth in Lined Ponds

Razorback suckers13 that had been13 in13 Pond 8 upper for the13 entire13 year13 grew an13

average of 0263 mmday (789 mmmonth) and razorback suckers that had been in the

pond for 7 months (Oct -shy‐ May) grew13 on13 average of 028 mmday (843 mmmonth) (Figure13

7) These growth13 rates13 did not significantly13 differ Fish density13 in Pond 3 during13 the13

majority of the growth period was13 00032 ndash 00036 fishgallon13 Additionally no13 significant

differences in growth rate were observed between fish smaller than 210 mm TL and fish

larger than 210 mm TL when all recaptured fish were combined

We also measured the growth rate of very large fish in a lined pond On Jan13 2513 201013

156 adult fish with PIT tags were recovered from13 Pond 3 upper13 These fish were13 in the13

pond for 257 days and experienced an average13 growth13 rate13 of 024mmday or 73

mmmonth (Figure13 7)13 This growth13 rate13 is slightly13 lower13 than13 the13 average13 growth13 rate13

observed13 at Bubbling13 Ponds Hatchery in other studies (0275 mmday 825 mmmonth)

but may not be biologically meaningful We would expect larger13 fish to13 have13 reduced

growth rates according to a typical Von Bertalanfy growth model (Bertalanffy 1957) but it

appears that13 over the size range we evaluated (300 -shy‐ 450 mm TL) growth rates have not

slowed significantly compared to that of smaller13 fish grown at Bubbling Ponds13 Hatchery

Growth13 of razorback suckers13 is known13 to13 slow as13 fish reach13 larger13 sizes but it appears13 this13

reduced growth rate may not really start to be biologically meaningful at Bubbling Ponds

Hatchery13 until razorback suckers13 exceed 450 mm TL

Growth in unlined ponds

Growth13 rates13 for the13 fish recaptured13 during13 the Pond 1 lower13 thinning13 (120 days13 in

the pond) was 024 plusmn 003 mmday (729 plusmn 090 mmmonth) (Figure13 8)13 Fish13 that were13 in

the pond for nearly the entire year grew13 an13 average13 of 024 plusmn 001 mmday (726 plusmn 027

mmmonth) These growth rates are surprisingly the lowest measured growth rates for

any part of our study and differ significantly from13 every other measured growth rate

except very large13 fish (Figure13 9)13 Separating13 out13 large fish that13 were in13 the pond for the

entire year makes no difference fish that were added to the pond at TL lt300 mm grew

43

13

Gro

wth

Rat

e (m

md

ay)

020

026

032

0244 plusmn 001 mmday (733 plusmn 028 mmmonth) and and those with TL gt= 300 mm at the

start of the experiment grew 022 plusmn 003 mmday (651 plusmn 101 mmmonth)

Razorback Growth Rates in Lined Ponds

Figure 7 Growth ofrazorback suckers in(mmday plusmn standard error)in Pond 8 upper in 2008-shy‐2009 An ANOVA did notdetect any significantdifferences

7 Months Full Year 300+ mm fish

Effects of sorting on growth

One hundred and seventy five tagged razorback suckers were recovered from13 Pond

8 upper13 on March13 24 2010 (378 days13 of growth)13 These were13 the13 larger sorted13 fish (gt140

mm TL) that came out of Pond13 5 on March13 11 2009 One13 hundred and13 twenty13 two13 tagged13

razorback suckers were also recovered from13 Pond13 7 upper on March13 31 2010 (385 days13 of

growth)13 These were13 the13 smaller sorted13 fish (lt140 mm TL) that came out of Pond13 5 on

March 1113 200913 No significant differences in growth rate (mmday) were observed among

larger fish in Pond 8 and smaller fish in Pond 7 (pgt005 ANOVA) (Figure 10)13 indicating

that13 sorting may have helped to offset the original slower growth trajectory of the smaller

fish Temperatures of Ponds 7 and 8 upper remained similar throughout the year13 (Figure

5)

44

13

13

13

Gro

wth

Rat

e (m

md

ay)

Gro

wth

Rat

e (m

md

ay)

020

026

032

020

026

032

Razorback Growth in an Unlined Pond

Figure 8 Growth of razorbacksuckers (mmday plusmn standard error) in Pond 1 lower (an unlined pond)in 2010-shy‐2011 An ANOVA did notdetect any significant differences

6 Months 12 Months lt 300 mm Fish 300+ mm Fish Growth Growth

Lined vs Earthen Ponds 1 year of growth

Figure 9 Growth of razorbacksuckers (mmday plusmn standard error) in lined and unlined ponds A t-shy‐test13 did not detect a significantdifference

Lined Pond Unlined Pond 1 Yr Growth 1 Yr Growth

45

13

Effect of Sorting G

row

th R

ate

(mm

day

) G

row

th R

ate

(mm

day

)

032

020

026

032

020

026

Smaller Fish Larger Fish

Effect of Ich

Figure 10 Average growthof razorback suckers(mmday plusmn standard error)that were size-shy‐sorted intosmall fish (pond 7) and largefish (pond 8) populations At-shy‐test did not detect asignificant difference

Figure 11 Average growth ofrazorback suckers (mmday plusmnstandard error) after Ich wasremovd from the hatcheryrsquos springand after Ich was again detected inthe pond The growth rate withoutIch is significantly higher than boththe rate after Ich and the ourstudyrsquos average annual growth ratein lined ponds (ANOVA p =00003)

Growth without Ich Growth With Ich Average Annual 4 months 4 months Growth Rate

46

13

Effect of Ich on razorback sucker growth rates

Seventy-shy‐four13 tagged13 razorback suckers13 were13 recovered from13 Pond 8 on September

15 2010 These fish had13 been13 in the pond for 4 months and experienced a growth rate of

032 mmday or 97 mmmonth (Figure13 11)13 This growth13 rate13 is significantly higher (p =

005 two sample t-shy‐test) than the mean growth rate for the same group13 of tagged fish after

Ich detection (022 mmday or 65 mmmonth) and significantly higher than any other

individual growth13 rates13 observed13 to13 date13 at Bubbling13 Ponds Hatchery13 (Figure13 11)13 If this13

growth13 rate13 were13 extended throughout13 the entire13 year13 fish on average from13 Ich-shy‐free13 ponds13

would be 16 mm longer than fish from13 ponds infested with Ich Studies conducted at

Bubbling Ponds hatchery in 2008 (Ward 2008) did not reveal any effects of the treatment

chemicals on razorback sucker growth rates so it13 is likely that13 the parasite outbreaks

themselves are causing reducing growth rates rather than the chemicals used to treat the

parasites13

Conclusions

Our results suggest that under typical hatchery operations (maximizing number of

fish produced)13 the growth13 rate13 of razorback13 suckers13 is relatively13 consistent at Bubbling13

Ponds hatchery13 at 02-shy‐03 mmday (6-shy‐9 mmmonth)13 but is lower than growth13 rates13 at

other13 facilities (02 ndash 18 mmday Ward et al 2007)13 This growth13 rate13 has13 been13 constant in

both lined and unlined ponds and at all fish densities we were able to measure To achieve13

growth13 rates13 substantially higher than this will likely require13 significant changes in rearing

practices that may not be practical in order to reach numerical production13 goals

Temperature is a key variable in fish growth but seasonal growth patterns

described13 above13 (Figure13 5) demonstrate that water temperatures are high enough in

winter to maintain razorback growth Differences in water temperature by season

currently13 do not fluctuate more than 10degC at Bubbling Ponds because of the continuous

supply of water flowing through each pond (approx 225 gallonsmin) These high water

flows appear to keep pond temperatures within the thermal preference13 for razorback

suckers13 (1213 -shy‐ 28 degC Bulkley and Pimentel 1983) throughout the entire year with

temperatures rarely dropping13 below 16deg13 C (Figures 513 6)13

47

13

Fish density is another key variable in fish growth and though the number of fish in

a pond during our study ranged from13 3000 to 700013 fish we13 did not find any13 correlation13

between13 density and growth rate13 This might yield two conclusions First13 razorback

growth13 may be changed equally13 by13 densities13 at the13 hatchery13 (ie13 a density13 of 3000 fish in a

pond is as stressful13 for razorbacks as a density13 of 7000 fish) An alternative is that other

factors13 such as disease outbreaks have13 stronger13 control over fish growth13 than13 density13

Fish density13 would13 have13 to13 be13 experimentally manipulated to test13 this13 and hatchery

operations (producing the maximum13 number of fish) prevented our manipulating density13

in ponds for this13 work The trouble with manipulating density demonstrates the difficulties

associated with changing13 hatchery13 practices experimenting with density would have

prevented BPH from13 meeting13 production13 goals Given that the stocking of smaller

razorbacks has met with very little success perhaps BPH goals could be changed from13

producing 12000 fish at 300+ mm per year to a smaller number of very large fish each

year Growing13 fewer13 larger13 fish could potentially be accomplished in the same time frame

as more smaller fish but a better understanding of how density alters growth rate would

be required to be confident13 of this

The very slow growth13 in the13 earthen13 unlined13 Pond 1 lower13 was very surprising We13

had13 anticipated13 that the13 diversified diet13 cover and13 other13 habitat features13 provided by13

unlined ponds would yield dramatically increased growth rates However these traits were

not enough to offset high fish densities and in fact the unlined pond in our study13 suffered

mortality to bring densities down to that observed normally in lined ponds

Our data13 suggest13 that razorbacks13 sucker13 growth13 rates13 are13 higher in lined13 ponds13

However we13 think the reasons13 for the13 very slow growth we observed13 in the13 unlined13 pond13

in our study13 is instead13 linked13 to13 the13 usage13 of Pond 1 lower13 during13 the13 study13 rather13 than13

intrinsic13 slow growth13 in earthen13 ponds First the pond was at extremely high density for at

least part of the study The volume of Pond 1 lower has not been estimated but hatchery

managers suggest 1500-shy‐2000 fish is an appropriate number of individuals so this pond

was at a very high density for much of the experiment Second dissolved oxygen is often

very low in the13 large13 earthen13 ponds during the heat of summer much lower than that of

lined ponds This will both limit the number of fish that can survive in the pond and almost

certainly13 increases stress13 of these13 fish potentially13 reducing growth13 The DO crashes also13

48

13

limit the amount of feed hatchery managers can give fish in these ponds sometimes for

days or weeks at a time which further reduces growth during warm13 weather

Our data13 suggests that13 growth rates at the Bubbling13 Ponds Fish Hatchery are likely

as high as possible given13 the pond densities required to meet production goals and the Ich-shy‐

infested water that feeds the facility Sorting practices are successful in helping as many

fish as possible reach stocking length as fast as possible Unlined ponds may be able to

grow13 large13 fish at low13 densities13 but whatever factors allow13 for that13 growth are not13 able to

overcome high fish density The removal of invasive13 fis that act as13 a host for the13 parasite13

Ich fish from13 the Bubbling13 Ponds spring13 allowed the highest13 growth rate at 032 mmday13

(96 mmmonth) but that growth rate decreased again as Ich re-shy‐infested13 the13 hatchery13

Consistently13 achieving13 growth13 rates13 as high or substantially13 higher than13 this13 will likely13

require13 significant changes in rearing practices that may not be practical in order to13 reach13

numerical production13 goals

Two major changes that might result in higher growth rates are substantially

reducing fish density and modifying the way spring water is delivered to the facility (via

either repeated chemical treatments or enclosed concrete water diversions) to eliminate

Ich from13 the hatchery source water Other potential changes not address by our work

include13 flow-shy‐training razorbacks much previous literature including MSCP-shy‐funded13 work

on razorback suckers13 suggests13 that fish growing13 in flowing water will grow13 faster than fish

in still water (Jorgensen and Jobling 1994) Furthermore there are a wide variety of

potential benefits associated with growing13 fish13 in flowing13 water in addition13 to increased

growth13 rates13 (Davidson13 199713 Castro13 et al13 2011) Another option13 for increasing13 growth13

rates13 include13 changing to13 intensive13 culture13 in large circular13 tanks

Finally given that the stocking of smaller razorbacks has met with very little

success13 perhaps13 BPH13 goals13 could13 be13 changed from13 producing 12000 fish at 300+ mm per

year to a smaller number of very large fish each year Growing fewer larger fish could

potentially be accomplished in the same time frame as more smaller fish but a better

understanding13 of how density13 alters growth13 rate13 would13 be13 required to13 be13 confident of this

49

13

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower13 Colorado13 River Multi-shy‐Species13

Conservation Program13 (LCRMSCP) under Work Task C10 We13 thank Ty Wolters13 Tom13

Burke13 and Eric13 Volkman for their support of this research and Frank Agygos and Dave

Billingsly13 of the Bubbling13 Ponds Fish Hatchery13 for their willingness to participate in13 this

research13 and13 for their technical assistance We also thank the LCRMSCP fish group from13

Boulder City13 NV for their assistance with harvesting13 ponds and tagging13 fish13

50

13

Literature13 CitedAnders P J 1998 Conservation aquaculture and endangered species can objective science13

prevail13 over risk13 anxiety Fisheries 23(11) 28-shy‐31

Anderson R O and R M Nuemann 1996 Length weight and associated structural indicesPages 447 ndash 482 in B R Murphy13 and D13 W Willis13 editors13 Fisheries techniques13 2ndedtion American Fisheries13 Society13 Bethesda13 Maryland

Bain M B J T Finn and H E Brooks 1988 Streamflow regulation and fish communitystructure13 Ecology13 69382-shy‐392

Bays J H Zarbock R Whitman and T Murphy 2005 Conceptual design and managementof native13 fish refugia on the13 lower13 Colorado13 River In13 CL Spring13 and13 S Leoneditors Proceedings of two symposia Restoring native fish to the lower ColoradoRiver13 interactions13 of native and non-shy‐native13 fishes 13ndash1413 July13 1999 Las13 Vegas13 Nevada13 Restoring13 natural function within a modified riverine environment thelower Colorado River13 8ndash913 July13 1998 U S Fish and13 Wildlife13 Service Southwestern13 Region Albuquerque New Mexico Pages 167-shy‐177

Bertalanffy L Von 1957 Quantitative laws in metabolism13 and growth13 Q Rev Biology 32217 ndash 231

Bingham T B Scheer and C McAda 2003 Propagation facilities in Grand Valley (24 RoadHatchery Horsethief13 Ponds and13 grow-shy‐out ponds) for captive13 rearing13 ofendangered13 fishes for the13 upper13 Colorado13 River basin13 Colorado River RecoveryProgram FY2003 annual project report13 US Fish and13 Wildlife13 Service GrandJunction13 4pp

Birchell G J and K Christopherson 2004 Survival growth and recruitment of larval andjuvenile razorback13 sucker (Xyrauchen texanus) introduced13 into13 floodplain13 depressions13 of the13 Green River Utah13 Final report13 Upper13 Colorado13 RiverEndangered Fish Recovery Program13 Project No C-shy‐6RZ Publication Number 04-shy‐1513 Utah13 Division of Wildlife13 Resources Salt Lake13 City13 Utah13 67 pages

Brannon E L 1993 The perpetual oversight of hatchery programs Fishery Research 1819-shy‐27

Brett J R 1979 Environmental Factors and growth pages 599-shy‐67513 InW S Hoar13 D13 J13 Randall and J R Brett (eds) Fish Physiology Volume 8 Bioenergetics and GrowthAcademic Press New York

Brooks J E 1986 Annual reintroduction and monitoring report for razorback suckerXyrauchen texanus in the Gila River Basin Arizona 1985 US Fish and WildlifeService13 Offices of Endangered13 Species and Fishery13 Resources Albuquerque 23 pp

51

13

Brunson13 R E and K D13 Christopherson13 200513 Larval13 razorback13 sucker and bonytailsurvival and13 growth13 in the13 presence13 of nonnative13 fish in the13 Baeser13 floodplainwetland of the middle Green River Final report prepared for Upper13 Colorado RiverBasin Endangered Fish Recovery Program Project No C-shy‐6-shy‐rz-shy‐bt Publication13 No 05-shy‐26 Utah13 Division of Wildlife13 Resources13 Vernal13 32 pp

Bulkley R V and R Pimentel 1983 Temperature preference and avoidance by adultrazorback suckers Transactions of the American Fisheries Society 112601-shy‐607

Burke13 T13 199513 Rearing13 wild razorback13 sucker larvae in13 lake-shy‐side13 backwaters13 LakeMohave ArizonaNevada Proceedings of the Desert Fishes Council 2635

Busacker G P I R Adelman and E M Goolish13 199013 Growth13 Pages 363 ndash 387 in C BSchreck and p B Moyle editors Methods for fish biology American FisheriesSociety Bethesda Maryland

Castro V B Grisdale-shy‐Helland S J Helland T Kristensen S M Jorgensen J Helgrud13 GClaireaux A P Farrell A Krasnov and H Takle 2011 Aerobic training stimulatesgrowth and promotes disease resistance in Atlantic salmon (Salmo salar)Comparative Biochemistry and Physiology -shy‐ Part A Molecular amp IntegrativePhysiology13 160(2) 278-shy‐290

Czapla T E 2002 Facilities plan for the production of endangered fishes to meet statestocking13 plans13 as13 part of the13 Upper13 Colorado13 River Endangered13 Fish RecoveryProgram Upper Colorado River Basin Recovery Implementation Program US Fishand Wildlife Service13 Denver13 9 pp

Davidson W 1997 The effects13 of exercise13 training on teleost fish a review of recentliterature Comput Biochem Physiol 117A67ndash75

Figiel Jr C R 2005 Annual report fiscal year 2004 Willow Beach National13 Fish HatcheryUS Fish and Wildlife13 Service Willow Beach 17 pp

Figiel Jr C R M E Ulibarri G Carmichael J Seals and J N Hanson 2005 Intensive13 fish13 culture of warmwater native fishes at a coldwater fish hatchery Pages 164-shy‐16613 inProceedings of two symposia restoring native fish to the lower Colorado13 River13 interaction13 of native13 and13 non-shy‐native13 fishes July13 13-shy‐1413 1999 Las Vegas Nevada USFish and Wildlife Service Southwest Region Albuquerque New Mexico

Gerking13 S D 1978 Ecology of freshwater fish13 production13 Halstead Press13 New13 York

Gustafson W and Q Bradwisch 2000 Wahweap operation and maintenance -shy‐-shy‐ UtahColorado River Recovery Program FY 2000 annual project report Project No 29cUtah13 Division of Wildlife13 Resources Page AZ 3pp

52

13

Hamman R L 1985 Induced spawning of hatchery-shy‐reared13 razorback sucker ProgressivFish Culturist 47(3) 187-shy‐189

Hanson J N 1996 Annual report fiscal year 1996 Willow Beach National Fish HatcheryUS Fish and Wildlife Service13 Willow Beach 9pp

Irving D S Seversen and M Montagne 2004 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2004 annual project13 report Report No 29b US Fish and13 Wildlife13 Service Vernal 3pp

Jorgensen E H and13 M Jobling 1994 Feeding and13 growth13 of exercised13 and13 unexercised13 juvenile Atlantic salmon in freshwater and performance after transfer to seawaterAquaculture International 2 154-shy‐164

Kaeding L R and D B Osmundson 198913 Colorado13 Squawfish13 and13 razorback sucker grow-shy‐out pond studies as part of conservation measures for the green mountain andRuedi reservoir water sales Final report for agreement number 6-shy‐AA-shy‐60-shy‐00150

Koebele13 B P13 198513 Growth and the size hierarchy effect an experimental assessment ofthree proposed mechanisms activity differences disproportional food acquisition13 pysiological stress Environmental Biology of Fishes 12 181-shy‐188

Kretschmann A E and L L Leslie 2006 Razorback sucker (Xyrauchen texanus) status13 reproduction and recruitment in Senator Wash Reservoir CA Final Report13 to USBurea of Reclamation Cooperative Agreement No 00-shy‐FG-shy‐34-shy‐ 0009 p 32 ArizonaGame and Fish Department Phoenix

Marsh13 P13 C13 1987a13 Digestive tract13 contents13 of adult razorback suckers13 in Lake13 MohaveArizona-shy‐Nevada Transactions of the American Fisheries Society 116117-shy‐119

Marsh P C 1987b Native fishes at Buenos Aires National Wildlife Refuge and ArizonaState University Research Park Arizona opportunities for management researchand public13 education13 on13 endangered species13 Proceedings of the Desert13 FishesCouncil 1967-shy‐78

Marsh P C 1994 Rearing native Colorado River fishes in golf course ponds Arizona StateUniversity Tempe 22 + pages

Marsh13 P13 C13 200013 Fish population13 status and evaluation13 in13 the Cibola13 High Levee PondFinal report agreement number 99-shy‐FG-shy‐30-shy‐00051 US Bureau of ReclamationBoulder City13 Nevada13 20 pages

Marsh P C and C A Pacey 1998 Growth of wild adult razorback suckers13 in Lake13 Mohave13 Arizona-shy‐Nevada13 Final report13 US Bureau of Reclamation Boulder City Nevada 25pages + appendices

53

13

Marsh P C B R Kesner and C A Pacey 2005 Repatriation as s management strategy13 to13 conserve a critically13 imperiled fish species North American Journal of FisheriesManagement 25 547-shy‐556

Marsh P C and C A Pacey 2005 Immiscibility of native and non-shy‐native13 fishes Pages 59-shy‐63 inMJ13 Brouder13 CL13 Springer13 and CS13 Leon13 editors13 Proceedings of two13 symposia Restoring native fish to the lower Colorado River interactions of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 NV and13 Restoring natural13 function within a modified riverine environment the lower Colorado River13 July13 8-shy‐913 1998 Las Vegas NV US Fish and13 Wildlife13 Service Southwest Region AlbuquerqueNew Mexico

Marsh13 P13 C13 and J13 E Brooks13 198913 Predation13 by ictalurid catfishes as a deterrent13 toreestablishment of hatchery-shy‐reared13 razorback sucker The Southwestern Naturalist34188-shy‐195

Matthews R A 2005 Ichthyopthirus multifiliis Fouquet and Ichthyopthirosis infreshwater13 teleosts13 Pages13 159-shy‐218 in Advances in Parasitology volume 59 J RBaker R Muller D Rollinson (eds) Academic Press

McCarthy13 M S and W L Minckley 1987 Age estimation for razorback sucker (PiscesCatostomidae) from13 Lake Mohave Arizona and Nevada Journal of the Arizona-shy‐Nevada Academy of Science 2187-shy‐97

Minckley13 W L13 198313 Status of the razorback13 sucker13 Xyrauchen texanus (Abbot)13 in13 thelower Colorado River basin13 The Southwestern13 Naturalist13 28(2) 165-shy‐187

Minckley13 W L13 199113 Native fished of the Grand Canyon13 region an obituary13 Pages 124-shy‐177 in Colorado River ecology and dam13 management National Academy PressWashington13 DC

Minckley13 C13 O and M LaBarbara13 199913 Report13 on13 native fish grow-shy‐out facilities13 at Cibolaand Imperial National Wildlife Refuges 1993-shy‐199513 US Fish and13 Wildlife Service13 Parker Fishery Resources Office Parker Arizona

Modde13 T13 199613 Juvenile razorback sucker (Xyrauchen texanus) in a managed wetlandadjacent13 to the Green13 River13 Great13 Basin13 Naturalist13 56375-shy‐376

Modde T KP Burnham and E J Wick 1996 Population status of the razorback sucker13 inthe middle Green River (USA) Conservation13 biology 10 110-shy‐119

Modde13 T13 and G13 B Haines13 200513 Survival13 and growth of stocked razorback13 sucker andbonytail in multiple floodplain wetlands of the middle Green River under resetconditions13 Final report prepared for Upper Colorado13 River13 Basin RecoveryImplimentation Program US Fish and Wildlife Service Vernal 66 pp

54

13

Modde T Z H Bowen and D C Kitcheyan 2005 Spatial and temporal use of a spawning13 site in the middle Green River by wild hatchery-shy‐reared13 razorback suckers13 Transactions of the American Fisheries Society 134937-shy‐944

Mueller13 G13 199213 The native fish work13 group13 -shy‐ a multiagency endeavor to improve thestatus of the razorback sucker in Lake Mohave AZ-shy‐NV13 Proceedings of the DesertFishes Council 2369

Mueller G 1995 A program13 for maintaining the razorback sucker in Lake MohaveAmerican Fisheries Society Symposium 15127-shy‐135

Mueller13 G13 200613 Ecology of the bonytail13 and razorback13 sucker and the role of offchannelhabitats13 in their13 recovery Scientific13 investigations13 report 2006-shy‐5065 US GeologicalSurvey13 Denver

Mueller G and E Wick 1998 Testing of golf course ponds at Page Arizona for suitability13 as grow-shy‐out facility for razorback sucker using surplus fish from13 Ouray NationalFish Hatchery National Park Service US Fish and13 Wildlife13 Service and UtahDivision of Wildlife13 Resources 28 pages

Mueller13 G13 and T13 Burke13 200513 Survival13 of young13 razorback13 sucker (Xyrauchen texanus) inrelation to13 stocking rates13 (fishha)13 and13 in the presence13 or absence13 of predatorcommunities in Lake Mohave Arizona-shy‐Nevada13 Pages13 155-shy‐16313 in Proceedings of two13 symposia restoring native fish to the lower Colorado River interaction13 of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 Nevada US Fish and Wildlife13 Service Southwest Region Albuquerque New Mexico

Mueller13 G13 J13 Carpenter13 and P13 C13 Marsh13 200413 Cibola13 High Levee Pond annual report 2004US Geological Survey Fort Collins13 Science Center13 Colorado13 and Arizona StateUniversity Tempe 23 pages

Nesler T P K Christopherson J M Hudson C W McAda F Pfeifer and T E Czapla 2003An integrated stocking plan for razorback sucker bonytail and Colorado13 pikeminnow for the Upper Colorado River Endangered Fish Recovery ProgramAddendum13 to State Stocking Plans Upper Colorado River Basin Recovery13 Implementation Program 12 pp

Papoulias13 D and W13 L Minckley13 1992 Effects13 of foo availability13 on survival and growth13 of larval razorback suckers13 in ponds Transactions of the American Fisheries Society121340-shy‐355

Paukert13 C P D L Ward13 P J Sponholtz13 and K13 D Hilwig13 Effects13 of repeated hoopnetting13 on bonytail chub13 Journal of Freshwater13 Ecology13 20(4) 649-shy‐653

Pfeifer F M13 C Baker13 and M13 Montagne13 199913 Propagation13 facilities13 in the13 Grand Valley13 (24 Road13 Hatchery13 Horsethief13 Ponds and13 grow-shy‐out ponds) for captive rearing of

55

13

endangered13 fishes for the13 Upper Colorado13 River Basin13 Colorado13 River Recovery13 Program FY 99 annual project report Project No 29a13 US Fish and Wildlife Service13 Grand13 Junction13 5pp

Pfeifer F S Seversen and M Montagne 2003 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2003 annual reportProject No 29b13 US Fish and Wildlife13 Service Vernal13 4pp

Rabago-shy‐Castro J L Sanchez13 J G Perez-shy‐Castaneda R and13 Gonzalez-shy‐Gonzlez A 2006Effects of the prophylactic use of Romet-shy‐3013 and13 copper13 sulfate13 on growth13 condition13 and feeding13 indicies in13 channel13 catfish (Ictalurus punctatus) Aquaculture 253 343-shy‐349

Reinitz GL L E Orme and F N Hitzel 1979 Variations of body compositio and growth13 among strains of rainbow trout Transactions of the American Fisheries Society 108204-shy‐207

Ruppert13 J13 B P B Holden13 and P D Abate 1999 Age estimation and growth of razorbacksucker13 Xyrauchen texanus in Lake13 Mead Nevada Proceedings13 of the Desert FishesCouncil 3040

Schnoor K D and J Logan 2002 Operation and maintenance of JW Mumma nativeaquatic13 species restoration facility Colorado Colorado River Recovery Program FY2002 annual project report13 Project No 29d Colorado13 Division of Wildlife Alamosa3pp

Salisbury13 L13 1998 Factors13 affecting razorback13 sucker growth13 in Lake13 Mohave backwaters13 MS Thesis13 Unviersity13 of Nevada13 Las13 Vegas

Schooley J13 D13 and P C13 Marsh13 2007 Stocking of endangerdd13 razorback13 suckers13 in thelower Colorado River Basin13 over three decades 1974-shy‐2004 North American Journalof Fisheries Management 27 43-shy‐51

Severson S H H M Tyus and G B Haines 1992 An evaluation of feeds for raisingrazorback sucker Xyrauchen texanus Journal of Applied Aquaculture 155-shy‐65

Toney D P 1974 Observations13 on the13 propagation13 and13 rearing13 of two13 endangered species13 in a hatchery environment Proceedings of the Annual Conference of the Western13 Association of State Game and Fish Commissions 54 252-shy‐259

Tyus H M13 1998 Razorback sucker13 (Xyrauchen texanus) recovery plan13 University13 ofColorado Center for Limnology Boulder13 76 pages

Tyus H M13 and13 S H Severson 1990 Growth13 and13 survival of larval razorback suckers fedfive formulated diets The Progressive Fish Culturist 52197-shy‐200

56

13

Ulibarri M E 2003 Annual report fiscal year 2001 Dexter National Fish Hatchery13 andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 26 pages

Ulibarri M E 2003 Annual report fiscal year 2002 Dexter National Fish Hatchery andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 59 pages

USBR 2006 Lower13 Colorado13 River Multi-shy‐Species Conservation Program final fishaugmentation plan Boulder City 19 pp

USFWS 2002 Razorback sucker (Xyraouchen texanus) recovery goals Amendment andsupplement to the Razorback Sucker Recovery Plan13 US Fish and Wildlife Service13 Region 6 Denver13 Colorado

USFWS 1999 Annual report 1999 Ouray National Fish Hatchery Vernal 25pp

USFWS 2004 Management plan for the big-shy‐river13 fishes of the13 lower13 Colorado13 river basinamendment and supplement to the bonytail humpback chub Coloradopikeminnow and razorback sucker recovery plans

USFWS13 2005 Station13 profile13 of the13 Dexter13 National Fish Hatchery13 and Technology CenterUS Fish and Wildlife13 Service Dexter

Valdez R A P G Mangan R Smith and B Nilson 1982 Upper Colorado River fisheriesinvestigations13 inW H Miller J J Valentine D L Archer H M Tyus R A Valdezand L13 Kaeding13 editors13 Colorado River Fishery13 Project13 Part 2 Field13 investigations13 US Bureau of Reclamation Salt Lake City Utah

WBNFH 2004 Culture methods of the endangered razorback sucker Xyrauchen texanusUS Fish and Wildlife13 Service Willow Beach National Fish Hatchery13 8 pp

Ward D 2008 Effects of disease treatments on growth of razorback sucker ReportSubmitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 Inpartial fulfillment of work task C10 agreement number 06FG30039

Ward13 D13 M Childs and W Persons 2007 Factors13 affecting13 growth13 of razorback sucker13 (Xyrauchen texanus) in captivity Literature review and knowledge assessmentReport Submitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 In partial fulfillment of work task C10 agreement number 06FG30039

57

Appendices

Appendix 1 Survey Questions Survey of Razorback Sucker Culture in the

Southwestern United States

The enclosed survey is being distributed by the Arizona Game and Fish Department to razorback sucker culture facilities throughout

the Southwestern United States The purpose of this survey is to consolidate information regarding culture of this species so that

appropriate facility improvements can be considered for Bubbling Ponds Hatchery in Arizona Specifically we wish to increase

growth rate and production efficiency at the hatchery Information gathered in this survey will be summarized in a final report to US

Bureau of Reclamation in Boulder City NV and disseminated to all facilities that participate in the survey A workshop to discuss

the findings of this study as well as to share general information concerning razorback sucker culture will be organized by the

Arizona Game and Fish Department at the conclusion of this study and all participants will be invited

Thank you for taking the time to fill out this survey Please contact Mike Childs if you have questions or would like to discuss the

survey

Mike Childs

mchildssedonanet

(928) 639-1346

(928) 634-1279

Facility_____________________________________ Date___________________

Contact Phone _____________________________

ContactPerson_______________________________

Contact Email _______________________________

1 Water quality ranges at this culture facility

Season

Spring (Mar-May) Summer (Jun-Aug) Fall (Sept-Nov) Winter (Dec-Feb)

Temperature (C)

PH

DO (mgL)

PO4 (mgL)

TDS (mgL)

Hardness (mgL)

CaCO3

Pathogens

37

13

that is enriched with spirulina and krill or razorback sucker diet made by Silvercupreg

depending on availability Fish are monitored visually and by sampling using a cast net

When a large number13 of fish have13 grown to13 the13 target size they13 are13 harvested13 by13 draining

the pond and seining13 Fish are again13 sorted by hand and the largest13 fish are stocked13 Fish

that13 have not13 reached the target13 size are returned to the ponds for further grow-shy‐out13 On13

average it13 takes one to two years for fish to reach the target13 size with fish growing13 an

average of 06 mmday Target numbers for production are 12000 razorback suckers

annually (300 mm TL) The biggest difficulty in rearing razorback suckers at Bubbling

Ponds13 Fish Hatchery13 is protozoan13 parasite13 infestations13 (Ich) and13 associated13 bacterial

infections that come from13 an open spring source that is inhabited by mosquitofish

Dexter National Fish Hatchery13

Dexter National Fish Hatchery maintains four separate razorback sucker13

broodstocks13 These fish are spawned on13 site and larval13 fish are placed directly into 01 acre

ponds at a density13 of about 20000 larvae13 per pond (50 ndash 100 thousand13 per13 acre)13 Ponds

are fertilized with alfalfa13 pellets and superphosphate two weeks prior to receiving13 larvae to

produce13 natural13 feed for larval13 fish13 Ponds are13 fertilized again with alfalfa13 pellets one week

after larvae are introduced13 Fish are fed a catfish starter diet13 (sizes 1-shy‐3) made by Rangenreg

that13 is enhanced with spirulina13 and krill13 and then switched over to the razorback13 diet13 once

they are large enough to eat 1mm13 crumble Fish are fed twice a day by hand four days a

week13 at 25-shy‐60 body weight Feed ration is decreased if excess feed is seen remaining

on the13 pond bottom13 following feedings Fish are not graded or sorted during this grow-shy‐out

period Razorback suckers are harvested in the fall by draining ponds completely Fish are

sorted13 at harvest and13 distributed13 to13 other13 facilities13 for further13 grow-shy‐out depending on13

current size requirements Razorback suckers are on average 100 ndash 200 mm TL after the

first growing13 season13 and13 generally13 take13 1 -shy‐18 months for a majority of the fish to reach

300 mm TL There are 16 different species of fish maintained at Dexter National13 Fish13

Hatchery13 and13 having sufficient pond13 space13 to13 grow out separate13 groups13 of fish is the13

limiting factor for production of razorback suckers at this location

14

13

Grand Valley13 Native13 Fish Facility13

The Grand Valley Native Fish Facility maintains its own brood stock13 in13 eight13 ponds

located at the Horsethief Basin Wildlife Area in Grand Junction Colorado Fish are

spawned13 on site13 and13 larvae13 are13 reared13 indoors in fiberglass13 tanks13 at the13 24-shy‐Road13 Fish13

Hatchery13 in Grand13 Junction The 24-shy‐Road13 Hatchery13 consists of two13 separate13 recirculating13

systems that operate using de-shy‐chlorinated13 city13 water13 and two13 large13 fluidized-shy‐ bed sand

filters13 and13 rotating-shy‐drum13 filters for waste removal Fish are held in 4-shy‐foot (n=78) or 8-shy‐foot

(n=14) diameter fiberglass tanks Larval fish are started on prepared feeds immediately

after swim-shy‐up and fed exclusively razorback feeds made by Silvercupreg Fish are started on

a 0-shy‐250 micron razorback diet for the first 10-shy‐1213 days13 and13 then13 fed with13 gradually13

increasing13 feed sizes based13 on observations of feeding13 (250 ndash 400 micron 1 starter) Feed

sizes are mixed when transitioning to the next larger feed size These razorback diets are

specially sifted by Dr Rick Barrows (USDA13 Hagerman experiment station Idaho)

Razorbacks13 are13 typically eating 1mm13 extruded pellets by the time they are 35 to 4 inches

in length Fish are fed approximately 70 body weight per day initially and then gradually

reduced to 15 body weight by the time they reach the 300 mm TL target size Fish are

fed seven days13 a week using13 12-shy‐hr13 belt feeders It takes13 12-shy‐16 months to grow fish to the

target13 size in13 the hatchery13

Razorback suckers are sorted after three months and culled to about 4000 fish per

family lot Culled fish are stocked into leased grow-shy‐out ponds Stocking densities for

juveniles in these ponds is based on previous13 stocking and harvest13 rates13 and is pond

specific13 Grow-shy‐out ponds are13 harvested13 periodically13 using Fyke13 nets13 or trap13 nets13 and13 fish of

the target size are stocked Disease problems (Ich Lernea) water quality problems (low

DO) and difficulty in removing all of the fish are challenges for grow-shy‐out of razorback

suckers13 in these13 natural ponds13

Fish reared13 in the13 24-shy‐Road facility are sorted again at four to five months of age into

small and large size groups to obtain more uniform13 growth rates Batch estimates of fish

weight are done every month for each tank A group of fish are weighed and counted to

give an average weight for the tank with lengths estimated based on a lengthweight chart13

The biggest difficulties13 for growing13 out razorback suckers13 at the13 24-shy‐Road13 Fish13 Hatchery13 are13

insufficient space and water flow (oxygen) to grow fish to the target size At the Horsethief

15

13

Basin13 Ponds where broodstock13 are reared13 diseases such as Ich are problematic because

water is pumped directly from13 the Colorado River

Ouray13 National Fish Hatchery13

Ouray13 National13 Fish Hatchery maintains its own broodstock and13 spawns13 fish on-shy‐site13

Larvae are transferred from13 indoor hatching tanks to unfertilized 02 acre outdoor ponds

and stocked at densities 10000 ndash 20000 larvae13 per13 pond13 Even13 though13 outdoor13 ponds13 are13

covered with13 bird13 netting13 avian predators13 still get caught in the13 nets13 if they13 can see fish

Ponds are dyed blue13 as the13 fish grow to13 prevent avian predation13 While in the outdoor

ponds13 fish13 are13 fed a slow-shy‐sinking salmon diet made by Silvercupreg twice daily by hand

Amount of feed is based on periodic sample counts Fish are grown until late September at

which time temperatures require that all fish13 other13 than13 adult broodstock13 be13 brought

inside for the winter Ponds are drained completely and fish are sorted by hand Fish that

have reached the target size (300 mm TL) are stocked into the Green and Colorado Rivers

All remaining fish are moved indoors13 and13 held13 in three-shy‐foot (n= 30) or eight-shy‐foot (n=27)

diameter circular tanks On average it takes 12 ndash 18 months to grow fish to the 300 mm TL

at Ouray13 hatchery13

Razorback suckers are held during the winter in a recirculating system13 that

operates13 using13 two13 large13 fluidized-shy‐bed sand filters and a rotating-shy‐drum13 filter for solids

removal Fish are fed the Silvercupreg razorback diet using belt feeders There is currently

capacity13 to13 hold13 only13 20000 200-shy‐300 mm TL fish inside the facility and any extra fish13 are13

stocked13 into13 floodplain-shy‐wetlands or used for research purposes13 Ouray no longer leases

any private grow-shy‐out ponds Grow-shy‐out ponds were troublesome due to poor water quality

harvesting13 difficulties13 and13 non-shy‐native13 fish introductions13 The biggest difficulty13 for

production13 of razorback13 suckers at the Ouray13 National13 Fish13 Hatchery13 is space13 during13 the

winter to maintain large numbers of fish and high iron and manganese in the well water

that must be filtered out prior to use

16

13

Willow Beach National Fish Hatchery13

Willow13 Beach National13 Fish Hatchery receives wild-shy‐caught larvae from13 Lake

Mohave Larvae are treated for diseases with formalin and malachite green and placed in

45 ten-shy‐gallon13 flow-shy‐through aquaria13 Recirculated13 solar heated water13 22-shy‐25deg C is used to13

allow production of warm13 water fish at this traditionally cold water facility (Figiel 2003

Figiel et al 2005) Fish are fed brine shrimp nauplii to satiation every hour and after 14

days small amounts of specialized larval fish diet (Encapsulon13 Cyclopeeze13 spirulina13 and

artificial plankton) are introduced After 30-shy‐6013 days13 fish are13 transferred13 to13 six13 32-shy‐gallon13

fiberglass troughs at densities of 1000 to 1500 fish per tank and then a month later moved

outside13 to13 eight recirculating13 raceways that use a combination of well water and solar-shy‐

heated water to maintain temperatures of 22 ndash 25deg C during the summer months

When13 in13 the outside raceways13 fish are fed the razorback13 diet13 using13 belt13 feeders and

fed by13 hand13 at 10 -shy‐ 70 body13 weight per13 day Feed amount is adjusted based on sample

counts according to a feed conversion program13 developed for razorback suckers by Willow

Beach Hatchery personnel This program13 uses length and number-shy‐per-shy‐pound generated

from13 several years of razorback growth data (Figure13 1) Fish are13 sorted13 opportunistically13

and are not handled during the summer months when water temperatures are above 20degC

In 2004 the target size for stocking was 325 mm TL or greater (WBNFH 2004) with a

target13 of producing13 6000 fish per year Reaching this13 target size usually13 takes13 two13 growing13

seasons13 The biggest difficulty13 in rearing13 razorback suckers13 at Willow Beach13 National Fish

Hatchery13 is insufficient space13 to13 grow fish to13 increased13 target sizes (400-shy‐500 mm TL)

Uvalde13 National Fish Hatchery13

Uvalde13 National Fish Hatchery13 in Texas13 receives 35000 ndash 60000 razorback sucker13

fry annually in MarchApril from13 Dexter National Fish Hatchery The fry are acclimated in

bags submerged in the pond for a minimum13 of one hour and released into13 a 1 acre13 fertilized13

pond where they are reared for the remainder of the summer Fingerlings are fed a starter

razorback diet when they reach approximately 50 mm TL In AprilMay the previous year

class of razorbacks are captured from13 their over-shy‐wintering pond enumerated graded and

split into13 one-shy‐acre grow-shy‐out ponds Approximately 4000 ndash 5000 fish will be13 placed13 in each13

one acre pond for summer grow-shy‐out Fish are reared for approximately 150 days (May ndash

17

13

Oct) and fed the Bozeman razorback diet two times a day five days a week at 15 ndash 30

body weight per day based on average water temperature

Figure 1 Relationship between length and number of fish per pound

In general13 juvenile razorback13 suckers (received as fry13 during13 the previous spring)13

reach the target size of 300 mm TL in approximately 6 months In 20062007 Uvalde

produced 6000 razorback suckers 300 mm TL for introduction into the San Juan River

Starting13 in 2008 Uvalde NFH will be producing13 and distributing13 12000-shy‐ 300 mm TL

razorbacks for stocking into the San Juan River Predation from13 migrating cormorants has

occurred but timing of harvest and over wintering protection methods such as covering

ponds with netting or placing fish indoors helps to minimize losses during the cormorant

migration (November to March) Uvalde has experienced razorback mortalities because of

bacterial problems but these are usually resolved through the use of oxytetracyline

medicated feed

Overview13 of Differences in Culture Methods

Several differences were noted when conducting surveys at each of the five main

production facilities for razorback sucker (See Appendix 3) These differences include

different stocking13 and13 rearing13 densities13 (Table13 4-shy‐5) various feeding regimes and type of

18

13

lt=amp

feeds (Table 7) as well as differences in grading or sorting practices Some of these

differences are13 related13 to13 whether13 or not razorback suckers13 are13 being13 reared13 in extensive-shy‐

culture13 facilities13 (ponds) or intensive-shy‐culture13 settings13 (raceways13 o tanks)13 Some13 practices13

are unique to a single facility13 or a couple of facilities (Table 6)13 Managers at each facility13

were asked to identify the biggest13 difficulty or constraint13 that13 they experience when13

growing-shy‐out juvenile13 razorback suckers13 at their13 respective13 location13 Space constraints13

water quality and disease problems were the main factors limiting production of razorback

suckers13 at these13 facilities13 (Table13 8) Calculated or reported growth rates from13 the literature

vary widely (Table 9) and range from13 02 to 18 mmday These growth rates indicate that

juvenile razorback suckers have a very high growth potential under optimal rearing

conditions13

Table13 4 Stocking13 densities13 for larvae13 and13 fry in ponds

$amp( )(+amp-( 01-2(3(4amp56( 4amp56(+amp-( 01-2782-( $amp () + --amp +amp0amp)+amp 12-3amp ( )+amp0amp+amp --amp +amp0amp)+amp 42556789amp8 ( +amp0ampgt+amp 3amp +amp0amp+amp A-BC-Damp (E + 3amp )+ F-6ltamp ) G+ 3amp G+

Table13 5 Rearing13 densities13 at intensive13 culture13 facilities13

$amp( )amp+(($-( $0( 12(3$+( 40((amp05( 67((amp05( 8$9(407$( $amp amp())amp++-$amp 0 1 0amp2amp1amp 3amp2amp4 0544

6amp())amp++-$amp 610 021 4amp2amp47amp 3amp2amp77amp 058 9$amplt+)amp 4amp())amp++-$amp 00 1 7amp2amp77amp 851amp2amp0amp 05

6amp())amp++-$amp 610 77amp2amp1amp 0amp2amp1amp 053

19

13

Table13 6 Rearing13 practices13 that are13 unique to13 specific rearing13 facilities13 $$amp( )$+-(amp$-(0(1-amp2034( $amp()amp+( -0$(12(33+(amp(amp134$53+(amp$amp3+(6amp+(

723(843(1$8(422(6amp+(42amp(4(423(19$43( 343( lt34$53(6amp+(6(4($03(amp4+94amp(842($1$1(63$$34(amp+(63626243( =amp+(gtamp94ampA( B3(1(1$+53+C3+(amp+(1$43(1(3D0$(1(amp443(amp+(amp443( 734231(amp( B3(1(193(44(1(34amp(amp(+49E(6amp+( -E3(F3+( G3amp(1(12(amp(H3(13$(4ampE(C(IJK($$amp( A( L43(+A3(4(6303amp4(63+4ampM(66$3D3amp4$(34amp(amp(6amp+(C((4amp3( L$$8(392(

B0$+3(

N43D(13+(4($0$(12M(amp+(639$53+($0$(12(+34( G3amp(12(amp(399$4amp(4+(938A(842($(2343+(843( N443D643+(3amp(12(amp(amp34(63amp(amp(423(O$+(G03( )amp+(3(134$53+(6(4(39364(1(1A(4(44(423D(amp((D3(amp4$(+34(

Table13 7 Types of feed used at razorback sucker13 hatcheries13 $amp ()amp+-amp0- $$)1amp23 45-amp)-$5)1amp23 $amp()amp+( -amp$amp+(amp+( -amp012$3+(amp+4(amp5215$(0+( 65ampamp7(85209(+2($1(87((15315lt=(+2(

+amp+amp(amp(55$5$2gt( 21( Aamp+(amp+( )amp+(012$3+(B29(5$05$95($$2(5amp+(

199524(amp5215$(0+( 65ampamp7(85209(+2($1(87(15315lt=(+2(amplt( 29gt(51($51(amp9(2(25=(C(DD(0+(

E15amp+(Famplt2amp( G1$5(lt1lt$51(25amp=( HIJKH(Dlt1amp(15315lt=(+2(I(C2(CH(+5gt( )11$gt($511(02+(15315lt=(+2(

$1(87(15315lt=(+2(D5$$(3(lt5$$gt(02+(gt( 6lt=(511B(

L15gt( G1$5(lt1lt$51(25amp=(Aamp+( amp+(

HIJKH(Dlt1amp(15315lt=(+2(I(C2(CH(+5gt( )11$gt($511(02+(15315lt=(+2(

$1(87(15315lt=(+2($1(87($B(amp=amp( 5$Damp(+2(

M$$B(5lt9(-5$+( NO515(G1$5(219( L2+1(15ltB5gt(Aamp+(5amp+( amp$amp+(amp+(

1amp(91D(amp5$(Pamplt5$amp4( 8gtlt$34(1$amp54(5amp+(5120lt5$( $5amp=2amp()amp+(012$3+(B29(5$05$95( $$2(5amp+(19952Q(amp12152( 1+lt2amp(

$1(87(15315lt=(+2($1(87(15315lt=(+2( $1(87(15315lt=(+2(

Table 8 Factors limiting production at major razorback sucker facilities

$amp( )amp+(-0+1((2$(0amp1ampamp(-34amp( $amp()amp+( -(01$2(34+(546(amp(0amp(01amp(541(13( -741( 803(3amp41amp4(9((+ltlt1amp4(03(amp(44amp(2=(4(

+ltlt3$4(4(2amp4amp(014(1gt13=(43=( 1amp+(amp34amp( 803(3amp41amp4(1$4+(4(541(A$4B(amp+(+$C+(

7Bamp($244amp(lt(1313$4amp(B42( D1B( E41(A$4B(01$2(3+(B(66(1amp(amp+(2ampamp(

Eamp41(420141(464(1A1($$(lt6(4((2C+(amp+1( 803(3amp41amp4(1$4+(4(541(A$4B(amp+(+$C+(7Bamp(

E$$5(36( 803(3amp41amp4F(15amp(lt6(4(amp31amp$B($11(gt( 1$4(amp(ampltlt3amp4(03(amp(44amp(lt1(amp5(lt6(

GC$+( 8221(420(3amp(4(6691A1amp(051((4(410$(+(4( 661(1amp+541(020amp(4(=0(0amp+(3$F(

20

13

$amp(

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lt(6(

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-(=22

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Table9Reportedandcalculatedgrowthratesfromtheliterature

Calculatedgrow

thratesbasedon

informationprovidedinliterature

aApproximationsofmaximum

grow

thpotential(basedon

average13 maximum

sizesiffishreportedatharvest

21

13

General Information on Factors that Affect Fish Growth

Growth in fish is extremely variable and is impacted by many different

physiological and environmental factors Growth rates are known to change with size and

age sex season activity level density amount13 of living space quality and quantity of food

genetics and temperature (Brett 1979) Growth experiments conducted at different times

of year can result in growth rates that are not comparable As fish become larger their

physiological13 potential to grow decreases making determination of growth rate dependent

on the size of the starting fish and the length of the experiment (Busacker et al 1990)

Genetic factors also have great potential to influence growth rate Some species have

strains13 and13 races13 that display vastly different growth potentials (Reinitz et al 1979) All of

these factors combine to make assessment of the individual factors controlling fish growth

difficult13

Water temperature is probably the most important variable affecting growth rate13

All of the basic functions that affect growth such as feeding digestion and metabolism are

temperature-shy‐dependent13 Growth13 is inseparably13 tied13 to13 bioenergetics13 and13 therefore13 also13

tightly tied to temperature When temperatures are below optimum daily temperature

fluctuations can stimulate growth Photoperiod is also commonly linked to water

temperature and can influence growth rates in fish (reviewed in Brett 1979)

Fish density13 is known to13 affect growth13 and13 can alter13 growth13 rates13 in several ways13

Fish that exhibit strong territorial behaviors13 or natural schooling tendencies13 will

experience reduced growth if densities are too high or too low (Brett 1979) Dominance

hierarchies where some fish feed more aggressively than others can also lead to high

variability13 in growth13 rates13 (Koebele13 1985) Crowded13 conditions13 also13 cause physical

interference13 between13 fish and13 poor water13 quality13 which13 reduces13 growth13 (Busacker13 et al13

1990) The effects of fish numbers space and feeding opportunity are frequently correlated13

and often13 difficult13 to distinguish (Brett13 1979)13

It is impossible to study the effects of environmental factors on growth without also

evaluating feed rations (Brett 1979) Amount of food quality of the diet particle size

number of feedings per day and time of feeding have all been shown to affect growth

(Busacker et al 1990) In controlled laboratory studies food is usually fed ad libitum13

22

13

(constantly available) and other variables are altered to assess impacts of environmental

factors13 on growth13 These studies13 are13 usually13 conducted13 in tanks13 or raceways13 because13

researchers must verify that food is constantly available to the fish which is difficult to do

in large pond environments where the fish and the bottom13 are often not visible (Busacker13

et al13 1990)

Specific Information13 o Razorback13 Sucker13 Growth

Variable13 growth

Growth in razorback suckers is naturally highly variable and may be a function of

their evolutionary history (USFWS13 2002)13 Minckley (1983) speculated that13 wide size

variation in a single cohort of razorback suckers may be adaptive with fast-shy‐growing13 fish

that13 reproduce at a young13 age surviving13 better in13 high discharge years and slow-shy‐growing13

smaller fish surviving better during drought periods This highly variable growth rate

makes rearing razorback suckers in a production setting difficult because fish from13 a single

cohort do not reach the target stocking size simultaneously One of the major tasks for

aquaculture is to maximize both individual growth and total production13 (Gerking13 1978)13

This becomes more difficult when the species being cultured exhibits highly variable

growth13 rates13 because of genetic influences as is the case with razorback13 suckers13

Razorback13 sucker growth13 is typically very13 rapid13 during13 the first13 year of life13 and then13

declines with age First year growth can be as low as 50 mm and as high as 350 mm (Valdez

et al13 1982 Minckley13 1983 Mueller13 1995) Razorback sucker13 grow rapidly13 for

approximately the first five or six years of life and then growth slows13 (McCarthy13 and13

Minckely 198713 Tyus 199813 Minckley et13 al 1991)13 Growth of older individuals in13 extant13 wild

populations is very13 low (Minckley 198313 Tyus 198813 Modde13 et al 1996)13 Wild growth13 rates

for mature adult fish in Lake Mohave based on PIT tag recaptures were often too small to

be accurately measured for both males and females over the time period of 1987-shy‐199713

(Marsh and Pacey 1998) This information suggest it will take substantially longer to rear

fish to13 increasingly13 larger13 stocking13 sizes (40013 ndash 500 mm TL) than it did to reach the target

size of 300 mm TL

Growth in ponds

23

13

One of the main strategies for maintaining genetic refugia and self-shy‐sustaining13

populations of razorback13 sucker in the lower Colorado13 River basin13 is to rear razorback13

sucker13 larvae13 in production13 ponds until they13 are13 a suitable13 size for stocking13 (USFWS13 2004)

Pond culture has proven useful to promote rapid growth of juvenile razorback suckers

(Kaeding and Osmundson 1989) Marsh (1994) reported that growth rates of razorback

suckers13 reared13 in golf-shy‐course13 ponds exceeded13 the13 best growth13 rates13 obtained13 under

intensive13 culture13 conditions13 at federal hatcheries13 especially13 during the13 first several years13

of life Growth rates in these semi-shy‐natural ponds are also comparable to estimated growth

rates13 of juvenile13 wild13 fish (McCarthy13 and13 Minckley13 1987) Modde13 and13 Haines13 (2005)

reported13 the13 greatest growth13 rates13 in the13 largest and13 deepest floodplains13 with13 the13 greatest

amount of submergent vegetation but excellent growth and survival of fish in a grow-shy‐out

pond is of little value if there is not an efficient way to collect the fish from13 the pond

(Kaeding and Osmundson 1989)

Temperature13

Bulkley and Pimentel (1983) used shuttle boxes in the laboratory to determine a

temperature preference13 for razorback suckers13 of 23-shy‐24degC13 In13 their13 studies13 razorback

suckers were found to avoid temperatures below 118 degC or above 286 degC Razorback

suckers at Bubbling Ponds Hatchery are more active in the spring and feed better as

photoperiod increases even prior to water temperatures rising (Frank Agygos personal

communication) Table 3 briefly summarizes water temperature data from13 each facility

Detailed seasonal water temperature profiles are not currently available for many

razorback grow-shy‐out sites13

Density13

Extensive studies have been conducted on commercially important species to

evaluate stocking densities and feeding rates that maximize production For these species

controlled experiments under laboratory conditions have established relationships

between temperature density and feed ration on growth (Brett 1979) but this information

is sporadic13 or non-shy‐existent for razorback suckers13 (Bays13 et al13 2005) Fish culturists13 with13

24

13

experience13 rearing13 razorback suckers13 typically13 have13 target stocking13 densities13 that13 they use

(Tables13 4 -shy‐ 5) These stocking densities have largely been determined over time by trial

and error These approximate stocking densities provide a good starting point for more

controlled13 types13 of replicated13 pond studies13

Feed ration

Razorback13 suckers are currently13 being13 fed a wide variety13 of prepared diets (Table 7)

that range from13 a slow-shy‐sinking salmon feed manufactured by Silver Cupreg to a spirulina

and krill-shy‐enhanced catfish feed made by Rangenreg Most locations are feeding 20 ndash 50

body13 weight per13 day13 Methods13 for culture13 of razorback sucker13 larvae13 in intensive13 settings13 at

fish hatcheries are well documented (Figiel 2005) and various larval fish diets have been

evaluated13 (Tyus and13 Severson 1990 Severson et al13 1992) but no standardized13 procedures

are used for feeding13 larval13 fish in13 intensive settings13

Razorback sucker larvae are also effectively reared in pond environments using

natural foods supplemented with larval fish diets and survival is high when no predators

are present13 (Mueller 2006)13 Growth rates for larval13 and early juvenile razorback13 suckers

may increase with pond fertilization Diet and physiological studies on wild razorback

suckers indicate that they feed on plankton as well as benthic organisms during their entire

life (Marsh 1987) Artificially fertilizing ponds may greatly increase production capacity

and growth rates for razorback13 sucker (Papoulias and Minckley13 1992) and warrants

further13 investigation13

Handling stress

Handling stress13 has13 been shown to13 influence growth13 rates13 Paukert13 et al (2005)

found that growth of bonytail chub was reduced by 26when compared with controls

after being13 repeatedly13 captured and handled in13 hoop13 nets13 Handling13 effects are likely13 to be

similar for razorback suckers that are repeatedly13 captured and sorted in13 a hatchery13 setting13

Razorback suckers that are handled at Willow Beach National Fish Hatchery will commonly

not eat for two weeks after handling (John Scott personal communication) This creates a

difficult situation13 for production13 facilities because13 fish13 need to be sorted to ensure13 large13

25

13

aggressive fish do not interfere with growth of smaller individuals but frequent handling

and sorting13 causes stress related reductions in13 growth13

Measuring Growth in Captive Fish

Weight is the traditional measure used to estimate growth or production in

aquaculture settings13 Groups of fish are typically13 weighed and an average individual13 weight13

is computed (Busacker et al 1990) Although this method is often logistically the easiest it

may not be the most informative for species with highly variable growth rates like

razorback suckers especially when target lengths must be reached before fish can be

stocked Weight can also be highly influenced by things like stomach fullness or

development of gonads (Busacker et al 1990) Condition factor or relative weight can also

be used to assess growth of fish but these tools may be more robust predictors of fecundity

than of growth (Anderson and Neuman 1996) For some species sexes need to be

distinguished because males and females may differ in morphology (Anderson and

Neumann 1996) Mueller (2006) analyzed growth rates based on PIT tag recaptures of 86

razorback suckers13 in High13 Levee Pond13 and13 found13 that differences13 in growth13 do not appear13

to occur until fish are over 450 mm TL at which time growth rate in males slows while

females continue to grow at a slightly higher rate This would indicate that sex may not be

an important factor to consider when examining growth rates unless the target grow-shy‐out

size is above 450 mm TL

The best measures of growth are often determined from13 the length and weight of

individuals rather than from13 groups of fish (Anderson and Nuemannn 1996) because

individual growth rates give better estimates of confidence and variance (Busacker et13 al

1990) Length frequency analysis or recapture of previously marked individuals of a known

size is likely to yield the most useful information for razorback sucker growth The success

of any of these methods depends on proper sampling procedures that are representative of

the population as a whole (Busacker et al 1990) Sampling methods that are known to be

size-shy‐biased such as trammel nets (Mueller et al 2004) or cast nets should not be used when

trying to measure growth rates13

26

13

Conclusions

For razorback sucker survival is largely associated with stocking size Additional

focused13 research13 is therefore13 needed to13 identify13 ways13 to13 increase13 growth13 rates13 of captive-shy‐

reared13 razorback sucker Growth13 rate13 in fish is controlled13 by many factors including fish

size and age temperature density and feed ration which can all be highly correlated

Growth of razorback suckers is also inherently variable which makes the task of identifying

the key factors that13 affect13 growth in13 captivity even more difficult The focus at most

razorback rearing facilities13 is production so the13 types13 of data that are13 collected13 are13 often

insufficient for detailed13 evaluations13 of individual rearing13 practices13 on growth13 Surveys of

existing13 razorback sucker13 rearing facilities indicate that culture methods vary widely and

the types of growth data13 that13 are collected are not13 standardized13 Replicated studies with

detailed information on rearing location water temperature initial stocking size stocking

density and the sizes of all fish at harvest are needed in order to compare the effects of

individual rearing practices on growth This type of research will ultimately provide both

time and cost-shy‐savings to production facilities by reducing the amount of time necessary13 for

razorback sucker to reach stocking size improving overall production efficiency

Optimum13 rearing densities for razorback sucker larvae and juveniles remain to be

determined Current stocking densities will be very useful as starting point for more

detailed studies and although optimum13 rearing densities are likely to be site-shy‐specific13

replicated studies on density will provide a valuable reference for hatchery managers

Frequency13 of sorting is another13 area that needs13 further13 research Frequent

handling13 and13 sorting13 can13 cause13 stress-shy‐related13 reductions13 in growth but not sorting can

create dominance hierarchies that further reduce growth rates of subordinate individuals

The effects13 of sorting13 on overall fish growth13 in both13 pond and13 intensive13 culture13

environments warrant further investigation Research techniques for these types of

experiments are well understood and typically utilize a matrix of replicate ponds per

variable (Bays et al 2005) In every case accurate and complete records of sampling

procedures and data collection are needed in order to interpret data and make inferences

about13 growth rates (Busacker et13 al 1990)13

27

13

Additional research is also needed to evaluate long-shy‐term13 survival of stocked fish

reared in ponds compared to fish13 reared13 in intensive13 culture13 facilities13 Exercise13

conditioning13 and predator-shy‐recognition training may also increase survival of stocked fish

and be more economically feasible than rearing fish to increasingly larger sizes prior to

stocking13 The success13 of traditional fish hatchery programs is measured largely by the

number of fish stocked but hatchery programs for endangered species must measure

success in terms of long-shy‐term13 survival and species recovery (Brannon 1993 Anders 1998)

A specific list of research recommendations follows

Specific Research13 Recommendations13

bull Use replicated studies13 to establish optimum stocking13 densities13 for ponds13 and

tanks13 that can be used as13 a starting13 point for site specific refinement

bull Determine if sortinggrading13 improves13 overall growth rates13 in both ponds13 and

intensive culture facilities13

bull Investigate the use of artificial fertilizers13 to improve growth of both juvenile

and adult razorback suckers13 in ponds13

bull Determine if the razorback sucker diet gives13 better growth rates13 than cheaper

catfish or salmon feeds

bull Evaluate growth rates13 and production potential of new intensive culture

methods13 such as13 large circular tanks13

bull Evaluate13 long-shy‐term survival of fish produced from raceways13 and circular tanks13

compared to fish reared in ponds13

bull Evaluate more effective means13 of treating13 fish diseases13

bull Evaluate factors13 other than size that may increase post-shy‐stocking13 survival such

as13 exercise conditioning13 predator recognition training or rearing13 under more

natural settings13

28

13

II The Effect of Disease Treatments on Razorback Sucker

Growth

Section13 SummaryFormalin copper sulfate potassium permanganate and13 salt are all chemicals commonly13 used13 to13 treat13 Ichthyophthirius multifiliis outbreaks in captive razorback sucker (Xyrauchen13 texanus) Weexposed 190 juvenile13 razorback suckers (127 ndash 26 mm TL) to13 5 5-shy‐day treatments with13 each13 chemical to evaluate the effects13 these chemicals13 may have on growth Fish grew an average of23513 mm TL13 during the month13 study period Fish treated with formalin grew on average13 29mm TL (03 mmday) while fish treated with copper had the lowest growth averaging 20 mmTL (021 mmday) No significant differences in13 growth were observed among fish treatedwith any of the chemicals compared to untreated fish (pgt005) Reductions in growth13 as aresult of repeated chemical treatments are not likely the cause of differences in growth ratesamong13 facilities that raise razorback suckers Repeated chemical treatments may13 have otherimpacts to overall13 fitness or long-shy‐term survival but13 these effects were not13 evident13 in our study

29

13

Introduction

Preservation13 of razorback sucker13 (Xyrauchen texanus) currently13 depends on captive13

rearing and stocking programs until permanent solutions to factors that prevent wild13

recruitment are found Low survival of stocked razorback suckers (Brooks 1986 Marsh

and Brooks 198913 Marsh and Pacey13 2005) has caused target13 sizes for stocked fish to

steadily increase in efforts to reduce predation mortality (Marsh et al 2005 Schooley and

Marsh 2007) Rearing fish to larger sizes at hatcheries comes with increased costs and

creates the need to evaluate husbandry and rearing practices that may affect fish growth

Formalin copper sulfate potassium13 permanganate and salt are all chemicals

commonly used at razorback sucker rearing facilities to treat outbreaks of the protozoan

parasite13 Ichthyophthirius multifiliis ldquoIchrdquo is one of the most pathenogenic diseases of

cultured13 freshwater13 fishes (Matthews13 2005) and causes large13 losses in captive13 populations13

of endangered razorback sucker Each of these chemicals used to treat Ich only kill the free-shy‐

swimming life stage of the parasite13 requiring13 repeated doses over several13 days depending13

on water temperature These chemicals treatments are needed to prevent loss as a result

of disease outbreaks but the cumulative effects repeated disease treatments have on

growth13 are13 unknown

Copper13 sulfate13 has13 been shown to13 significantly13 reduce13 growth13 of channel catfish13 in

production13 ponds (Rabago-shy‐Castro13 2006) but it is unknown whether13 razorback suckers13

experience similar reduced growth following copper treatment Quantifying the impacts of

disease treatments on growth will help to interpret the wide differences in growth rates

observed13 at various13 razorback sucker13 production13 facilities13 throughout the13 southwest

(Ward et al 2007) If one chemical is found to have less detrimental impacts on growth

than another then it may be preferred for use as a disease treatment We evaluated growth

rates13 of razorback suckers13 under13 replicated13 and13 controlled13 conditions13 to13 assess13 effects13 of

repeated formalin copper sulfate and potassium permanganate and salt treatments on

growth13

Methods

We captured 190 juvenile razorback suckers from13 ponds at Bubbling Ponds Fish

Hatchery AZ using hoop nets or cast nets All fish were of the same age class and

30

13

averaged 179 mm total length (TL) (range13 = 127 ndash 262 mm TL)13 These fish were13 offspring13

of captive13 razorback sucker13 broodstock held13 at Dexter13 National13 Fish Hatchery13 NM13 (2007

year class) All fish were tagged with passive integrated transponder (PIT) tags and

quarantined for one month prior to the experiment to allow fish to recover from13 tagging

and become accustomed to being held in circular tanks

At the beginning of the study all fish were weighed measured and scanned for

individual tag numbers with 19 randomly selected fish placed into each13 of 10 8-shy‐foot

diameter circular tanks (Figure 2)13 Each13 tank contained13 two13 airstones13 and13 an13 individual

biofilter with a recirculating water pump (31 litersminute) that had been operating for

at least 1 month prior to the experiment to allow bacterial colonies to become

established Two tanks were designated as a control and did not receive any chemical

treatments while the other eight tanks received formalin copper sulfate potassium13

permanganate or salt treatments at two week intervals (two tanks per chemical

treatment) Formalin copper sulfate and potassium13 permanganate were treated at 1 part

per million (ppm) and salt was applied at 30 parts per thousand (ppt) These treatment

rates are commonly used to treat13 razorback13 suckers for ich at Bubbling13 Ponds Fish13

hatchery (Frank Agygos personal communication)

Figure 213 Photo ofexperimental tankswith individualbiofilters and aeration

31

13

Each treatment consisted of a series of doses applied on Wednesday Thursday and

Friday with a 90water change between each dose Biofilters were removed from13 all

tanks and held in a separate holding facility during treatments and then replaced on the

Monday following treatments after a 90water change This schedule allowed fish to be

exposed to chemical treatments for 5 consecutive days without water quality deteriorating

This 5-shy‐day chemical treatment was repeated every two weeks from13 July to October (97

days)13 for a total of 5 5-shy‐day treatments Water temperature in the treatment tanks ranged

from13 13degC (55degF) to 32degC (91degF)

Fish were fed a fixed ration of commercial razorback diet (Silvercup 4mm13 pellet)

once daily13 (2 percent body13 weight per day13 as calculated13 by13 average initial fish weight)13

At the end of the experiment all fish were again weighed measured and scanned for

individual tag numbers Growth of fish in each treatment group was compared using

analysis of variance (ANOVA) Any mortalities13 that occurred during the13 study13 were13

replaced with previously quarantined fish of equivalent size to maintain equal densities in

each13 tank13 but growth13 data was13 only13 recorded for fish which13 survived13 the13 entire13

experiment

Results

Fish at the13 start of the experiment averaged 179 mm TL (Range13 = 127 ndash 262 mm)

with no significant differences in fish length among treatment groups (F(4189) = 00183 p

gt 0999 ANOVA) On average fish grew 235 mm TL (024 mmday) during the 3 month

study13 Fish in tanks13 treated with formalin had the highest growth averaging 29 mm TL (03

mmday) while fish in tanks treated with copper had the lowest growth averaging 20 mm

TL (021 mmday) Fish in the control tanks averaged 213 mm TL in growth (022

mmday) (Figure13 3)13 Formalin-shy‐treated fish grew13 significantly faster than13 any other

treatment group but no13 significant differences in growth13 in length13 or weight were13

observed among fish treated with any of the chemicals compared to untreated (control)

fish (pgt005 ANOVA)

32

13

Figure 313 Average growthof razorback suckersexposed to a series of 5 5-shy‐day chemical treatmentsover a 97-shy‐day13 periodError bars representstandard error

Discussion13

Growth13 rates13 observed13 in our study13 (021 ndash 03 mmday) are low compared to those

reported13 in other13 studies13 of razorback sucker13 growth13 (0213 ndash 18 mmday) (Ward et al

2007) Using recirculating water systems for our study required filters to be removed and

replaced during treatments Stress to fish caused by removing and replacing filters within

the tanks as well as repeated water changes may have led to overall higher stress and

reduced growth rates compared to those reported for unconfined fish Growth in fish is

highly variable and is affected by many different physiological and environmental factors

including fish size density temperature amount of space and food (Brett 1979) We

strived to control each of these factors but other factors may have also influenced growth

in our experimental tanks During mid-shy‐summer water temperatures in the treatment

tanks reached 32degC (91degF) At these warm13 temperatures fish are very susceptible to

bacterial13 infections13 The slightly higher growth exhibited by fish in the formalin and

potassium13 permanganate treatments may have been the result of these two chemicals

33

13

being effective at controlling bacterial infections The differences in growth we measured

among treatment groups were not statistically significant and do not appear13 biologically13

meaningful during the relatively short duration of this study (97 days) although the

cumulative effects of slightly reduced growth could be biologically meaningful over longer

time frames

Reductions in growth13 as a result13 o repeated chemical treatments are not likely the

cause of differences in growth rates among facilities that raise razorback suckers

Repeated chemical treatments may have other impacts to overall fitness or long-shy‐term13

survival but these13 effects13 were13 not evident in our study It is more likely that the parasite

outbreaks themselves are the cause of different growth rates among razorback rearing

facilities rather than the chemical treatments used to treat the parasites We recommend

that hatchery managers continue to use the chemicals that are most effective at controlling

ldquoIchrdquo13 at their individual13 facilities

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower Colorado Rive Multi-shy‐species13

Conservation Plan under Work Task C10 We thank Ty Wolters and Tom13 Burke for their

support of this research and Frank Agygos and Dave Billingsly of the Bubbling Ponds Fish

Hatchery13 for their13 technical assistance13 and13 help with13 collecting13 fish

34

13

III13 Razorback Growth Rates at Bubbling Ponds ndash 2009-shy‐2011

Section13 SummaryExperimental studies at Bubbling Ponds Fish Hatchery AZ have strived to understand

factors that affect razorback sucker growth in captivity and identify ways to improve growthrates and maximize size at release Rather than performing experimental studies that wouldrequire major13 rearrangement (and likely reduced production)13 of hatchery operations our13 studies13 used normal variation in production techniques13 and practices13 to isolate factors13 thatmay modify growth rates

Our initial work identified razorback13 growth rates in13 lined ponds at standard fishdensity as 026 to13 028mmday (789 to 843 mmmonth) No significant differences in growthrate were observed among fish that had been in the pond only during the winter13 periodcompared to fish that had been in the pond the entire year indicating that water temperatures13 at Bubbling Ponds are high enough to allow fish to incorporate feed effectively year-shy‐roundHowever these growth rates are lower than most values reported from the literature fromnatural or semi-shy‐natural pond environments No significant differences in13 growth rate wereobserved13 between large and13 small fish13 within the 150 ndash 29 mm TL13 size range Additional worksuggests13 that razorback suckers13 tagged at over 300 mm TL had reduced growth rates (024mmday 73 mmmonth) as would be expected according to a typical Von13 Bertalanfy growthcurve although growth rates13 were only slightly less13 than the average growth rate for thehatchery (027513 mmday 82513 mmmonth)

Sorting13 to13 separate small fish from large fish after the first year of growth is practicedesigned13 to allow smaller fish to ldquocatch uprdquo to larger fish We found that13 this technique doesappear to13 improve growth rates of smaller fish Growth rates of sorted small razorback suckers(029 mmday 87mmmonth)13 were equal to that13 of larger13 fish (028 mmday 8413 mmmonth)indicating that sorting may have helped to offset their original slower growth trajectory

Bubbling Ponds Fish Hatchery grows razorbacks in 6 long deep ponds lined with heavyplastic 2 long deep13 earthen13 (unlined) ponds and three wide shallow earthen ponds The wideshallow ponds13 have historically produced very large fish at low density but have been found tomaintain much lower fish numbers than deeper ponds We found13 that growth13 rates ofrazorbacks kept at high density (4-shy‐700013 fish)13 in a wide shallow pond grew extremely slowly(024 mmday 726 mmmonth) This growth rate is among the slowest of any fish over theyears of our study and demonstrates that13 though the large ponds may produce large fish at lowdensity13 they are unable to overcome high13 fish13 densities

Finally one of the major factors influencing13 fish13 growth13 in hatcheries is disease onemajor summer-shy‐time disease at13 Bubbling Ponds is the ectoparasite Ich (Ichthiopthirusmultifiliis) To investigate the impact Ich has on razorback growth we eradicated fish from thespring and water conveyance ditch that supplies13 water to the hatchery using Rotenone This13 restoration effort was fairly short-shy‐lived (Ich returned to the hatchery within four months) but

35

13

growth13 rates of fish13 reared for four months without Ich present (031 mmday 92 mmmonth)were significantly higher than the following 8 months of growth for those same fish (022mmday 65 mmmonth) This disease-shy‐free growth rate is in fact faster than any13 otherprevious growth rates observed at the hatchery in our study

We conclude that growth rates at the Bubbling Ponds Fish Hatchery are likely as highas possible given the pond densities required to13 meet production goals and the Ich-shy‐infestedwater13 that feeds the facility Sorting practices are successful in helping as many fish as possiblereach stocking length as fast as possible Unlined ponds may be able to grow large fish at lowdensities but whatever factors allow for that growth13 are not able13 to overcome13 high fish densityThus the large lower ponds at Bubbling Ponds may be better utilized via renovation to13 deepenand line them

Disease is the most important factor limiting growth as may be expected to be the caseat many13 hatcheries While the spring renovation was not13 a complete success13 the dramaticreduction of fish populations in that habitat was enough to dramatically13 reduce13 the13 occurrenceof Ich at the hatchery13 Such open spring13 systems feeding a hatchery are a misfortune that canbe expected to transmit disease so we suggest that renovating the spring again to combat13 IchImproved techniques to divert water from13 the springs and more throuough treatment ofstream-shy‐side vegetation may improve the success of chemical treatment Successful renovationwould likely both improve growth rates and reduce chemical costs associated with treating Ichoutbreaks Even13 if complete renovation13 is impossible or impractical an13 effort to reduceinvasive fish density in the springs13 which act a vector for the parasite(and thereby reduce thelikelihood of13 Ich being transmitted into ponds) may still13 show dramatic improvements

36

13

Introduction

Conservation efforts13 for razorback sucker13 (Xyrauchen texanus)13 currently13 depend on

captive rearing and stocking programs Low survival of stocked razorback suckers (Brooks

1986 Marsh13 and13 Brooks13 1989 Marsh13 and13 Pacey13 2005) has13 caused13 target sizes for stocked13

fish to steadily increase in efforts to reduce predation mortality13 (Marsh13 et al13 2005

Schooley and Marsh 2007) Rearing fish to larger sizes at hatcheries comes with increased

costs and creates the need to evaluate husbandry and rearing practices that may affect fish

growth13 We evaluated growth13 rates13 of individual razorback suckers13 in ponds13 at Bubbling

Ponds Fish Hatchery13 using Passive Integrated13 Transponder (PIT) tags13 to13 obtain13 precise

growth information for individual fish so that valid comparisons of growth rates as related

to rearing practices can be made

Due to the critical nature of the razorback sucker stocking program we did not

design experimental studies that would require major rearrangement and potentially

reduce production of hatchery operations Instead our studies used normal variation in

production techniques and practices to isolate factors that may modify growth rates

Though this methodology dramatically limits replication and may limit our ability to

directly13 attribute13 differences in growth13 rates13 to13 the13 variables13 we13 investigate13 we13 were13 able13

to accomplish research goals without altering hatchery operations or impacting

production

From13 2009 through 2011 we conducted a series of observational13 growth13 studies to

determine growth rates of individual razorbacks at Bubbling Ponds The first set of

experiments included13 identifying13 growth13 rates13 in lined13 and13 unlined13 ponds determining

growth13 rates13 of fish at different13 sizes13 in13 relation13 to sorting13 practices and monitoring

razorback growth rates after removing the source of the ectoparasite13 Ich (Ichthiopthirus

multifiliis) from13 the hatchery water source13

Razorback growth rate in lined ponds

Our first growth study documented individual growth rates at normal density in 11

million gallon lined ponds13 over two13 years13 This is the standard13 grow-shy‐out process for

razorbacks13 at Bubbling Ponds We monitored growth of fish for a variety13 of sizes and13 the13

37

13

amount of time in a pond during the growing season These13 data give a snapshot of growth13

rates13 at the13 facility13 and13 provide13 the basis for comparisons throughout our study

Growth rate13 in an unlined pond

In addition13 to 6 ponds lined with heavy plastic13 sheeting13 Bubbling Ponds Fish13

Hatchery maintains two narrow and deep (same dimensions as lined ponds13 Figure13 4)13 and13

three large13 shallow unlined ponds These earthen13 ponds typically have vegetation and

associated aquatic invertebrates that may better simulate natural environments by

providing cover and improved food diversity or quality Therefore these unlined ponds

may be expected to produce higher growth rates and potentially improved survival that is

more similar to growth rates observed in more natural grow-shy‐out facilities13 Historically13 the13

large13 shallow13 ponds have produced very large fish when13 utilized at low13 fish density13 The

narrow13 deep earthen13 ponds are13 used to grow13 fry13 at high density in their first13 year of life

The major downside to unlined ponds is the difficulty in harvesting fish where a lined

pond might take 8-shy‐1013 people13 a half13 day13 to13 harvest13 lined13 ponds13 require13 intensive13 weeding13

to allow seines to be pulled and therefore require many more personnel-shy‐hours13 In addition13

to harvest challenges the shallow earthen ponds tend to suffer from13 dissolved oxygen

crashes during the summer Unlined ponds also may maintain higher13 populations13 of non-shy‐

target species such as bluegill sunfish mosquito fish and bullfrog tadpoles We measured

growth rates of suckers in a large shallow earthen pond for comparison to growth in lined

ponds13

Figure13 4 Lined13 and13 earthen ponds13 of similar dimensions (approx 1000000 gallons first

and second panels) and a large13 shallow13 earthen13 pond (third panel)

38

13

Effect of sorting on growth

Razorback13 suckers13 are13 currently13 sorted13 after their first13 year of growth13 They are13

typically removed from13 one of the13 upper earthen13 ponds and13 split into13 two13 lined13 ponds for

subsequent grow-shy‐out13 The larger13 fish (gt approximately 140 mm) are placed into one pond

and the smaller individuals in another It is possible that the larger fish were more

aggressive or adept13 at taking food so this sorting process is intended to allow smaller fish

to improve their growth rate

Effect of Ich on razorback sucker growth rates

We13 evaluated13 growth13 rates13 of razorback sucker13 in the13 presence13 and absence of the

ectoparasite13 Ich (Ichthiopthirus multifiliis) Ich outbreaks can occur in wild populations13 but

hatcheries13 have13 proven excellent locations13 for Ich because13 of very high fish densities13 which13

facilitate13 the13 transfer13 of Ich13 between13 fish This common fish parasite causes direct mortality13

to razorback13 suckers as well13 as secondary bacterial13 infections13

The open spring and13 ditch13 which13 provides water to the Bubbling13 Ponds Hatchery

has long13 been infested with mosquitofish (Gambusia affinis) that harbor13 the13 Ich parasite13

and allow13 it13 to enter the hatchery with incoming13 water13 The solution13 to13 the13 Ich problem13

was to remove the mosquitofish host using13 Rotenone Razorback13 sucker growth13 rates were13

then tracked in13 the absence of this parasite for 4 months and compared with growth rates

after Ich returned to the pond and from13 previous years

Methods

Razorback growth rate in lined ponds

On May 14 2008 141 razorback suckers were tagged with 12 mm PIT tags (1342

kHz) and placed in Pond 3 (approximately 1100000 gallons13 Figure13 4)13 at Bubbling13 Ponds

Fish Hatchery Fifty-shy‐three of these tags were recovered two months later when a large

Ichthyophthirius multifilis (Ich) outbreak killed many fish in the pond On October 15 2008

an additional13 145 PIT tagged13 fish were13 also placed into Pond13 3 On13 May13 14 2009 Pond13 3

was harvested and a total13 of 141 PIT tagged fish were recovered13 Of the tagged fish13 26 fish

had13 been13 in the13 pond since May13 of 2008 (378 days13 o growth) and 115 had been13 in13 the

39

13 40

pond since October13 15 2008 (211 days13 of growth) Numbers of fish in Pond 3 after the Ich

outbreak and for the majority of the period of growth were between 3 000 and 4000 fish

A Hobotempreg temperature13 logger13 was13 also13 installed13 in Pond 3 one meter below the water

surface13 near13 the13 outflow and13 recorded water temperature every 3 hours to allow analysis

of the effects of water temperature on growth rate (Figure13 5) This Hobotemp data is

representative of other pond temperatures throughout this study

In a second experiment 210 adult13 razorback suckers13 were13 PIT tagged13 on13 May 14

2009 and13 placed13 into13 Pond13 3 upper to13 evaluate13 growth13 rates13 of larger13 razorback suckers13 at

Bubbling13 Ponds Hatchery13 under current13 rearing13 conditions13 Size of these fish at tagging13

was (mean = 285 mm range = 205 ndash 396 mm) These fish remained in the pond for 257

days and were harvested on Jan 25 2010 to provide information on growth rates of larger

razorback suckers13 under13 current rearing conditions

Figure 513 Temperatures (degC) inrearing pond at BubblingPonds Hatchery from July toSept 2009 (top graph)13 andfrom Nov to Dec 2009 (Lowergraph) Temperaturesrecorded with a Hobotempregremote data logger13 every 3hours

13

Growth rate13 in an unlined pond

To document razorback sucker growth in earthen ponds we introduced13 225 tagged13

razorback suckers13 into13 Pond13 1 lower13 (Figure 4) in February 3 2010 Additional tagged fish

from13 other studies were added to the pond throughout the growing season and the density

of 1 lower reached a maximum13 of nearly 7000 fish in early summer 2010 Density was

reduced to approximately 6000 fish by capturing fish with hoop nets on June 3 2010 54 of

these fish were tagged fish and returned to 1 lower after being weighed and measured The

pond was harvested on January13 2713 2011 and a total13 of 254 tagged fish out13 of 4296 fish

total were removed from13 the pond The pond was harvested on January 27 2011 (358 days13

of growth) and the tagged fish were weighed and measured Total number of razorbacks in

the pond at harvest13 was 4296

Effect of sorting practices on growth rates

On March 1113 200913 Pond13 5 upper was13 harvested13 and13 split into13 two13 separate13 groups

Two hundred of the smaller fish (average size = 122 mm TL) were PIT tagged and placed

into13 Pond13 7 upper and13 200 of the13 larger13 fish (average = 160 mm TL) were PIT tagged and

placed int Pond13 8 upper Density13 in Pond13 7 was13 4500 fish and13 in Pond13 8 there13 were13 6500

fish These ponds were then harvested after 1 year and growth rates were compared to

give information on the effects of current sorting practices Hobotempreg temperature

loggers were installed in13 Ponds 7 and13 8 during13 the13 grow-shy‐out period with13 water13

temperature recorded every 2 hours13 (Figure13 6)

Effect of Ich on razorback sucker growth rates

Bubbling Ponds spring was treated with Rotenone (CFT Legumine 5) at a

concentration of 2 ppm13 to remove all mosquitofish from13 the spring The treatment

consisted of two treatments 6 hours in duration on two consecutive days (April 12 -shy‐ 13)

using13 drip13 stations13 and13 backpack sprayers13 followed13 by13 an13 additional 6 hours13 of

detoxification using sodium13 permanganate Although 12 mosquitofish were captured in the

spring pond the week following the treatments subsequent minnow trapping (20 traps

checked13 daily13 for 3 weeks) did not capture any additional fish until August 11 2010 when

41

13

juvenile mosquitofish were again detected in the spring pond Minnow traps have

subsequently been set daily with several hundred individuals removed To evaluate if Ich

was also again present in the spring we captured 15 mosquitofish from13 the spring pond on

three separate days and placed them13 in an aquaria at 25 degC with 5 longfin dace known to be

free of Ich These fish were monitored for 2 weeks with no signs of Ich developing This

indicates that even though mosquitofish have returned to the spring pond the parasite is no

longer present13 although how13 long13 this condition13 will13 persist13 is unknown13

On May 1113 201013 200 juvenile razorback13 suckers were harvested out13 of Pond 5

upper (2009 year Class from13 Dexter National Fish Hatchery) and were PIT tagged and

placed into Pond 8 to evaluate if growth rates at bubbling ponds hatchery have improved

following the renovation of the spring and the removal of the Ich parasite Unfortunately13

on Sept13 8 2010 Ich was13 again13 detected13 in Pond 8 and the pond was immediately seined

and 74 tagged fish were measured to obtain growth information for the 4-shy‐month period

during13 which13 the13 pond13 was13 Ich-shy‐free13

Figure13 6 Temperatures (degC) in rearingponds 7 and 8 at Bubbling Ponds Hatchery13 from March 2009 ndash March 201013 pond 7(top13 graph)13 and13 pond 8 (Lower13 graph)13 Temperatures recorded with a Hobotempregremote data logger every 3 hours

42

13

Results

Growth in Lined Ponds

Razorback suckers13 that had been13 in13 Pond 8 upper for the13 entire13 year13 grew an13

average of 0263 mmday (789 mmmonth) and razorback suckers that had been in the

pond for 7 months (Oct -shy‐ May) grew13 on13 average of 028 mmday (843 mmmonth) (Figure13

7) These growth13 rates13 did not significantly13 differ Fish density13 in Pond 3 during13 the13

majority of the growth period was13 00032 ndash 00036 fishgallon13 Additionally no13 significant

differences in growth rate were observed between fish smaller than 210 mm TL and fish

larger than 210 mm TL when all recaptured fish were combined

We also measured the growth rate of very large fish in a lined pond On Jan13 2513 201013

156 adult fish with PIT tags were recovered from13 Pond 3 upper13 These fish were13 in the13

pond for 257 days and experienced an average13 growth13 rate13 of 024mmday or 73

mmmonth (Figure13 7)13 This growth13 rate13 is slightly13 lower13 than13 the13 average13 growth13 rate13

observed13 at Bubbling13 Ponds Hatchery in other studies (0275 mmday 825 mmmonth)

but may not be biologically meaningful We would expect larger13 fish to13 have13 reduced

growth rates according to a typical Von Bertalanfy growth model (Bertalanffy 1957) but it

appears that13 over the size range we evaluated (300 -shy‐ 450 mm TL) growth rates have not

slowed significantly compared to that of smaller13 fish grown at Bubbling Ponds13 Hatchery

Growth13 of razorback suckers13 is known13 to13 slow as13 fish reach13 larger13 sizes but it appears13 this13

reduced growth rate may not really start to be biologically meaningful at Bubbling Ponds

Hatchery13 until razorback suckers13 exceed 450 mm TL

Growth in unlined ponds

Growth13 rates13 for the13 fish recaptured13 during13 the Pond 1 lower13 thinning13 (120 days13 in

the pond) was 024 plusmn 003 mmday (729 plusmn 090 mmmonth) (Figure13 8)13 Fish13 that were13 in

the pond for nearly the entire year grew13 an13 average13 of 024 plusmn 001 mmday (726 plusmn 027

mmmonth) These growth rates are surprisingly the lowest measured growth rates for

any part of our study and differ significantly from13 every other measured growth rate

except very large13 fish (Figure13 9)13 Separating13 out13 large fish that13 were in13 the pond for the

entire year makes no difference fish that were added to the pond at TL lt300 mm grew

43

13

Gro

wth

Rat

e (m

md

ay)

020

026

032

0244 plusmn 001 mmday (733 plusmn 028 mmmonth) and and those with TL gt= 300 mm at the

start of the experiment grew 022 plusmn 003 mmday (651 plusmn 101 mmmonth)

Razorback Growth Rates in Lined Ponds

Figure 7 Growth ofrazorback suckers in(mmday plusmn standard error)in Pond 8 upper in 2008-shy‐2009 An ANOVA did notdetect any significantdifferences

7 Months Full Year 300+ mm fish

Effects of sorting on growth

One hundred and seventy five tagged razorback suckers were recovered from13 Pond

8 upper13 on March13 24 2010 (378 days13 of growth)13 These were13 the13 larger sorted13 fish (gt140

mm TL) that came out of Pond13 5 on March13 11 2009 One13 hundred and13 twenty13 two13 tagged13

razorback suckers were also recovered from13 Pond13 7 upper on March13 31 2010 (385 days13 of

growth)13 These were13 the13 smaller sorted13 fish (lt140 mm TL) that came out of Pond13 5 on

March 1113 200913 No significant differences in growth rate (mmday) were observed among

larger fish in Pond 8 and smaller fish in Pond 7 (pgt005 ANOVA) (Figure 10)13 indicating

that13 sorting may have helped to offset the original slower growth trajectory of the smaller

fish Temperatures of Ponds 7 and 8 upper remained similar throughout the year13 (Figure

5)

44

13

13

13

Gro

wth

Rat

e (m

md

ay)

Gro

wth

Rat

e (m

md

ay)

020

026

032

020

026

032

Razorback Growth in an Unlined Pond

Figure 8 Growth of razorbacksuckers (mmday plusmn standard error) in Pond 1 lower (an unlined pond)in 2010-shy‐2011 An ANOVA did notdetect any significant differences

6 Months 12 Months lt 300 mm Fish 300+ mm Fish Growth Growth

Lined vs Earthen Ponds 1 year of growth

Figure 9 Growth of razorbacksuckers (mmday plusmn standard error) in lined and unlined ponds A t-shy‐test13 did not detect a significantdifference

Lined Pond Unlined Pond 1 Yr Growth 1 Yr Growth

45

13

Effect of Sorting G

row

th R

ate

(mm

day

) G

row

th R

ate

(mm

day

)

032

020

026

032

020

026

Smaller Fish Larger Fish

Effect of Ich

Figure 10 Average growthof razorback suckers(mmday plusmn standard error)that were size-shy‐sorted intosmall fish (pond 7) and largefish (pond 8) populations At-shy‐test did not detect asignificant difference

Figure 11 Average growth ofrazorback suckers (mmday plusmnstandard error) after Ich wasremovd from the hatcheryrsquos springand after Ich was again detected inthe pond The growth rate withoutIch is significantly higher than boththe rate after Ich and the ourstudyrsquos average annual growth ratein lined ponds (ANOVA p =00003)

Growth without Ich Growth With Ich Average Annual 4 months 4 months Growth Rate

46

13

Effect of Ich on razorback sucker growth rates

Seventy-shy‐four13 tagged13 razorback suckers13 were13 recovered from13 Pond 8 on September

15 2010 These fish had13 been13 in the pond for 4 months and experienced a growth rate of

032 mmday or 97 mmmonth (Figure13 11)13 This growth13 rate13 is significantly higher (p =

005 two sample t-shy‐test) than the mean growth rate for the same group13 of tagged fish after

Ich detection (022 mmday or 65 mmmonth) and significantly higher than any other

individual growth13 rates13 observed13 to13 date13 at Bubbling13 Ponds Hatchery13 (Figure13 11)13 If this13

growth13 rate13 were13 extended throughout13 the entire13 year13 fish on average from13 Ich-shy‐free13 ponds13

would be 16 mm longer than fish from13 ponds infested with Ich Studies conducted at

Bubbling Ponds hatchery in 2008 (Ward 2008) did not reveal any effects of the treatment

chemicals on razorback sucker growth rates so it13 is likely that13 the parasite outbreaks

themselves are causing reducing growth rates rather than the chemicals used to treat the

parasites13

Conclusions

Our results suggest that under typical hatchery operations (maximizing number of

fish produced)13 the growth13 rate13 of razorback13 suckers13 is relatively13 consistent at Bubbling13

Ponds hatchery13 at 02-shy‐03 mmday (6-shy‐9 mmmonth)13 but is lower than growth13 rates13 at

other13 facilities (02 ndash 18 mmday Ward et al 2007)13 This growth13 rate13 has13 been13 constant in

both lined and unlined ponds and at all fish densities we were able to measure To achieve13

growth13 rates13 substantially higher than this will likely require13 significant changes in rearing

practices that may not be practical in order to reach numerical production13 goals

Temperature is a key variable in fish growth but seasonal growth patterns

described13 above13 (Figure13 5) demonstrate that water temperatures are high enough in

winter to maintain razorback growth Differences in water temperature by season

currently13 do not fluctuate more than 10degC at Bubbling Ponds because of the continuous

supply of water flowing through each pond (approx 225 gallonsmin) These high water

flows appear to keep pond temperatures within the thermal preference13 for razorback

suckers13 (1213 -shy‐ 28 degC Bulkley and Pimentel 1983) throughout the entire year with

temperatures rarely dropping13 below 16deg13 C (Figures 513 6)13

47

13

Fish density is another key variable in fish growth and though the number of fish in

a pond during our study ranged from13 3000 to 700013 fish we13 did not find any13 correlation13

between13 density and growth rate13 This might yield two conclusions First13 razorback

growth13 may be changed equally13 by13 densities13 at the13 hatchery13 (ie13 a density13 of 3000 fish in a

pond is as stressful13 for razorbacks as a density13 of 7000 fish) An alternative is that other

factors13 such as disease outbreaks have13 stronger13 control over fish growth13 than13 density13

Fish density13 would13 have13 to13 be13 experimentally manipulated to test13 this13 and hatchery

operations (producing the maximum13 number of fish) prevented our manipulating density13

in ponds for this13 work The trouble with manipulating density demonstrates the difficulties

associated with changing13 hatchery13 practices experimenting with density would have

prevented BPH from13 meeting13 production13 goals Given that the stocking of smaller

razorbacks has met with very little success perhaps BPH goals could be changed from13

producing 12000 fish at 300+ mm per year to a smaller number of very large fish each

year Growing13 fewer13 larger13 fish could potentially be accomplished in the same time frame

as more smaller fish but a better understanding of how density alters growth rate would

be required to be confident13 of this

The very slow growth13 in the13 earthen13 unlined13 Pond 1 lower13 was very surprising We13

had13 anticipated13 that the13 diversified diet13 cover and13 other13 habitat features13 provided by13

unlined ponds would yield dramatically increased growth rates However these traits were

not enough to offset high fish densities and in fact the unlined pond in our study13 suffered

mortality to bring densities down to that observed normally in lined ponds

Our data13 suggest13 that razorbacks13 sucker13 growth13 rates13 are13 higher in lined13 ponds13

However we13 think the reasons13 for the13 very slow growth we observed13 in the13 unlined13 pond13

in our study13 is instead13 linked13 to13 the13 usage13 of Pond 1 lower13 during13 the13 study13 rather13 than13

intrinsic13 slow growth13 in earthen13 ponds First the pond was at extremely high density for at

least part of the study The volume of Pond 1 lower has not been estimated but hatchery

managers suggest 1500-shy‐2000 fish is an appropriate number of individuals so this pond

was at a very high density for much of the experiment Second dissolved oxygen is often

very low in the13 large13 earthen13 ponds during the heat of summer much lower than that of

lined ponds This will both limit the number of fish that can survive in the pond and almost

certainly13 increases stress13 of these13 fish potentially13 reducing growth13 The DO crashes also13

48

13

limit the amount of feed hatchery managers can give fish in these ponds sometimes for

days or weeks at a time which further reduces growth during warm13 weather

Our data13 suggests that13 growth rates at the Bubbling13 Ponds Fish Hatchery are likely

as high as possible given13 the pond densities required to meet production goals and the Ich-shy‐

infested water that feeds the facility Sorting practices are successful in helping as many

fish as possible reach stocking length as fast as possible Unlined ponds may be able to

grow13 large13 fish at low13 densities13 but whatever factors allow13 for that13 growth are not13 able to

overcome high fish density The removal of invasive13 fis that act as13 a host for the13 parasite13

Ich fish from13 the Bubbling13 Ponds spring13 allowed the highest13 growth rate at 032 mmday13

(96 mmmonth) but that growth rate decreased again as Ich re-shy‐infested13 the13 hatchery13

Consistently13 achieving13 growth13 rates13 as high or substantially13 higher than13 this13 will likely13

require13 significant changes in rearing practices that may not be practical in order to13 reach13

numerical production13 goals

Two major changes that might result in higher growth rates are substantially

reducing fish density and modifying the way spring water is delivered to the facility (via

either repeated chemical treatments or enclosed concrete water diversions) to eliminate

Ich from13 the hatchery source water Other potential changes not address by our work

include13 flow-shy‐training razorbacks much previous literature including MSCP-shy‐funded13 work

on razorback suckers13 suggests13 that fish growing13 in flowing water will grow13 faster than fish

in still water (Jorgensen and Jobling 1994) Furthermore there are a wide variety of

potential benefits associated with growing13 fish13 in flowing13 water in addition13 to increased

growth13 rates13 (Davidson13 199713 Castro13 et al13 2011) Another option13 for increasing13 growth13

rates13 include13 changing to13 intensive13 culture13 in large circular13 tanks

Finally given that the stocking of smaller razorbacks has met with very little

success13 perhaps13 BPH13 goals13 could13 be13 changed from13 producing 12000 fish at 300+ mm per

year to a smaller number of very large fish each year Growing fewer larger fish could

potentially be accomplished in the same time frame as more smaller fish but a better

understanding13 of how density13 alters growth13 rate13 would13 be13 required to13 be13 confident of this

49

13

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower13 Colorado13 River Multi-shy‐Species13

Conservation Program13 (LCRMSCP) under Work Task C10 We13 thank Ty Wolters13 Tom13

Burke13 and Eric13 Volkman for their support of this research and Frank Agygos and Dave

Billingsly13 of the Bubbling13 Ponds Fish Hatchery13 for their willingness to participate in13 this

research13 and13 for their technical assistance We also thank the LCRMSCP fish group from13

Boulder City13 NV for their assistance with harvesting13 ponds and tagging13 fish13

50

13

Literature13 CitedAnders P J 1998 Conservation aquaculture and endangered species can objective science13

prevail13 over risk13 anxiety Fisheries 23(11) 28-shy‐31

Anderson R O and R M Nuemann 1996 Length weight and associated structural indicesPages 447 ndash 482 in B R Murphy13 and D13 W Willis13 editors13 Fisheries techniques13 2ndedtion American Fisheries13 Society13 Bethesda13 Maryland

Bain M B J T Finn and H E Brooks 1988 Streamflow regulation and fish communitystructure13 Ecology13 69382-shy‐392

Bays J H Zarbock R Whitman and T Murphy 2005 Conceptual design and managementof native13 fish refugia on the13 lower13 Colorado13 River In13 CL Spring13 and13 S Leoneditors Proceedings of two symposia Restoring native fish to the lower ColoradoRiver13 interactions13 of native and non-shy‐native13 fishes 13ndash1413 July13 1999 Las13 Vegas13 Nevada13 Restoring13 natural function within a modified riverine environment thelower Colorado River13 8ndash913 July13 1998 U S Fish and13 Wildlife13 Service Southwestern13 Region Albuquerque New Mexico Pages 167-shy‐177

Bertalanffy L Von 1957 Quantitative laws in metabolism13 and growth13 Q Rev Biology 32217 ndash 231

Bingham T B Scheer and C McAda 2003 Propagation facilities in Grand Valley (24 RoadHatchery Horsethief13 Ponds and13 grow-shy‐out ponds) for captive13 rearing13 ofendangered13 fishes for the13 upper13 Colorado13 River basin13 Colorado River RecoveryProgram FY2003 annual project report13 US Fish and13 Wildlife13 Service GrandJunction13 4pp

Birchell G J and K Christopherson 2004 Survival growth and recruitment of larval andjuvenile razorback13 sucker (Xyrauchen texanus) introduced13 into13 floodplain13 depressions13 of the13 Green River Utah13 Final report13 Upper13 Colorado13 RiverEndangered Fish Recovery Program13 Project No C-shy‐6RZ Publication Number 04-shy‐1513 Utah13 Division of Wildlife13 Resources Salt Lake13 City13 Utah13 67 pages

Brannon E L 1993 The perpetual oversight of hatchery programs Fishery Research 1819-shy‐27

Brett J R 1979 Environmental Factors and growth pages 599-shy‐67513 InW S Hoar13 D13 J13 Randall and J R Brett (eds) Fish Physiology Volume 8 Bioenergetics and GrowthAcademic Press New York

Brooks J E 1986 Annual reintroduction and monitoring report for razorback suckerXyrauchen texanus in the Gila River Basin Arizona 1985 US Fish and WildlifeService13 Offices of Endangered13 Species and Fishery13 Resources Albuquerque 23 pp

51

13

Brunson13 R E and K D13 Christopherson13 200513 Larval13 razorback13 sucker and bonytailsurvival and13 growth13 in the13 presence13 of nonnative13 fish in the13 Baeser13 floodplainwetland of the middle Green River Final report prepared for Upper13 Colorado RiverBasin Endangered Fish Recovery Program Project No C-shy‐6-shy‐rz-shy‐bt Publication13 No 05-shy‐26 Utah13 Division of Wildlife13 Resources13 Vernal13 32 pp

Bulkley R V and R Pimentel 1983 Temperature preference and avoidance by adultrazorback suckers Transactions of the American Fisheries Society 112601-shy‐607

Burke13 T13 199513 Rearing13 wild razorback13 sucker larvae in13 lake-shy‐side13 backwaters13 LakeMohave ArizonaNevada Proceedings of the Desert Fishes Council 2635

Busacker G P I R Adelman and E M Goolish13 199013 Growth13 Pages 363 ndash 387 in C BSchreck and p B Moyle editors Methods for fish biology American FisheriesSociety Bethesda Maryland

Castro V B Grisdale-shy‐Helland S J Helland T Kristensen S M Jorgensen J Helgrud13 GClaireaux A P Farrell A Krasnov and H Takle 2011 Aerobic training stimulatesgrowth and promotes disease resistance in Atlantic salmon (Salmo salar)Comparative Biochemistry and Physiology -shy‐ Part A Molecular amp IntegrativePhysiology13 160(2) 278-shy‐290

Czapla T E 2002 Facilities plan for the production of endangered fishes to meet statestocking13 plans13 as13 part of the13 Upper13 Colorado13 River Endangered13 Fish RecoveryProgram Upper Colorado River Basin Recovery Implementation Program US Fishand Wildlife Service13 Denver13 9 pp

Davidson W 1997 The effects13 of exercise13 training on teleost fish a review of recentliterature Comput Biochem Physiol 117A67ndash75

Figiel Jr C R 2005 Annual report fiscal year 2004 Willow Beach National13 Fish HatcheryUS Fish and Wildlife13 Service Willow Beach 17 pp

Figiel Jr C R M E Ulibarri G Carmichael J Seals and J N Hanson 2005 Intensive13 fish13 culture of warmwater native fishes at a coldwater fish hatchery Pages 164-shy‐16613 inProceedings of two symposia restoring native fish to the lower Colorado13 River13 interaction13 of native13 and13 non-shy‐native13 fishes July13 13-shy‐1413 1999 Las Vegas Nevada USFish and Wildlife Service Southwest Region Albuquerque New Mexico

Gerking13 S D 1978 Ecology of freshwater fish13 production13 Halstead Press13 New13 York

Gustafson W and Q Bradwisch 2000 Wahweap operation and maintenance -shy‐-shy‐ UtahColorado River Recovery Program FY 2000 annual project report Project No 29cUtah13 Division of Wildlife13 Resources Page AZ 3pp

52

13

Hamman R L 1985 Induced spawning of hatchery-shy‐reared13 razorback sucker ProgressivFish Culturist 47(3) 187-shy‐189

Hanson J N 1996 Annual report fiscal year 1996 Willow Beach National Fish HatcheryUS Fish and Wildlife Service13 Willow Beach 9pp

Irving D S Seversen and M Montagne 2004 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2004 annual project13 report Report No 29b US Fish and13 Wildlife13 Service Vernal 3pp

Jorgensen E H and13 M Jobling 1994 Feeding and13 growth13 of exercised13 and13 unexercised13 juvenile Atlantic salmon in freshwater and performance after transfer to seawaterAquaculture International 2 154-shy‐164

Kaeding L R and D B Osmundson 198913 Colorado13 Squawfish13 and13 razorback sucker grow-shy‐out pond studies as part of conservation measures for the green mountain andRuedi reservoir water sales Final report for agreement number 6-shy‐AA-shy‐60-shy‐00150

Koebele13 B P13 198513 Growth and the size hierarchy effect an experimental assessment ofthree proposed mechanisms activity differences disproportional food acquisition13 pysiological stress Environmental Biology of Fishes 12 181-shy‐188

Kretschmann A E and L L Leslie 2006 Razorback sucker (Xyrauchen texanus) status13 reproduction and recruitment in Senator Wash Reservoir CA Final Report13 to USBurea of Reclamation Cooperative Agreement No 00-shy‐FG-shy‐34-shy‐ 0009 p 32 ArizonaGame and Fish Department Phoenix

Marsh13 P13 C13 1987a13 Digestive tract13 contents13 of adult razorback suckers13 in Lake13 MohaveArizona-shy‐Nevada Transactions of the American Fisheries Society 116117-shy‐119

Marsh P C 1987b Native fishes at Buenos Aires National Wildlife Refuge and ArizonaState University Research Park Arizona opportunities for management researchand public13 education13 on13 endangered species13 Proceedings of the Desert13 FishesCouncil 1967-shy‐78

Marsh P C 1994 Rearing native Colorado River fishes in golf course ponds Arizona StateUniversity Tempe 22 + pages

Marsh13 P13 C13 200013 Fish population13 status and evaluation13 in13 the Cibola13 High Levee PondFinal report agreement number 99-shy‐FG-shy‐30-shy‐00051 US Bureau of ReclamationBoulder City13 Nevada13 20 pages

Marsh P C and C A Pacey 1998 Growth of wild adult razorback suckers13 in Lake13 Mohave13 Arizona-shy‐Nevada13 Final report13 US Bureau of Reclamation Boulder City Nevada 25pages + appendices

53

13

Marsh P C B R Kesner and C A Pacey 2005 Repatriation as s management strategy13 to13 conserve a critically13 imperiled fish species North American Journal of FisheriesManagement 25 547-shy‐556

Marsh P C and C A Pacey 2005 Immiscibility of native and non-shy‐native13 fishes Pages 59-shy‐63 inMJ13 Brouder13 CL13 Springer13 and CS13 Leon13 editors13 Proceedings of two13 symposia Restoring native fish to the lower Colorado River interactions of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 NV and13 Restoring natural13 function within a modified riverine environment the lower Colorado River13 July13 8-shy‐913 1998 Las Vegas NV US Fish and13 Wildlife13 Service Southwest Region AlbuquerqueNew Mexico

Marsh13 P13 C13 and J13 E Brooks13 198913 Predation13 by ictalurid catfishes as a deterrent13 toreestablishment of hatchery-shy‐reared13 razorback sucker The Southwestern Naturalist34188-shy‐195

Matthews R A 2005 Ichthyopthirus multifiliis Fouquet and Ichthyopthirosis infreshwater13 teleosts13 Pages13 159-shy‐218 in Advances in Parasitology volume 59 J RBaker R Muller D Rollinson (eds) Academic Press

McCarthy13 M S and W L Minckley 1987 Age estimation for razorback sucker (PiscesCatostomidae) from13 Lake Mohave Arizona and Nevada Journal of the Arizona-shy‐Nevada Academy of Science 2187-shy‐97

Minckley13 W L13 198313 Status of the razorback13 sucker13 Xyrauchen texanus (Abbot)13 in13 thelower Colorado River basin13 The Southwestern13 Naturalist13 28(2) 165-shy‐187

Minckley13 W L13 199113 Native fished of the Grand Canyon13 region an obituary13 Pages 124-shy‐177 in Colorado River ecology and dam13 management National Academy PressWashington13 DC

Minckley13 C13 O and M LaBarbara13 199913 Report13 on13 native fish grow-shy‐out facilities13 at Cibolaand Imperial National Wildlife Refuges 1993-shy‐199513 US Fish and13 Wildlife Service13 Parker Fishery Resources Office Parker Arizona

Modde13 T13 199613 Juvenile razorback sucker (Xyrauchen texanus) in a managed wetlandadjacent13 to the Green13 River13 Great13 Basin13 Naturalist13 56375-shy‐376

Modde T KP Burnham and E J Wick 1996 Population status of the razorback sucker13 inthe middle Green River (USA) Conservation13 biology 10 110-shy‐119

Modde13 T13 and G13 B Haines13 200513 Survival13 and growth of stocked razorback13 sucker andbonytail in multiple floodplain wetlands of the middle Green River under resetconditions13 Final report prepared for Upper Colorado13 River13 Basin RecoveryImplimentation Program US Fish and Wildlife Service Vernal 66 pp

54

13

Modde T Z H Bowen and D C Kitcheyan 2005 Spatial and temporal use of a spawning13 site in the middle Green River by wild hatchery-shy‐reared13 razorback suckers13 Transactions of the American Fisheries Society 134937-shy‐944

Mueller13 G13 199213 The native fish work13 group13 -shy‐ a multiagency endeavor to improve thestatus of the razorback sucker in Lake Mohave AZ-shy‐NV13 Proceedings of the DesertFishes Council 2369

Mueller G 1995 A program13 for maintaining the razorback sucker in Lake MohaveAmerican Fisheries Society Symposium 15127-shy‐135

Mueller13 G13 200613 Ecology of the bonytail13 and razorback13 sucker and the role of offchannelhabitats13 in their13 recovery Scientific13 investigations13 report 2006-shy‐5065 US GeologicalSurvey13 Denver

Mueller G and E Wick 1998 Testing of golf course ponds at Page Arizona for suitability13 as grow-shy‐out facility for razorback sucker using surplus fish from13 Ouray NationalFish Hatchery National Park Service US Fish and13 Wildlife13 Service and UtahDivision of Wildlife13 Resources 28 pages

Mueller13 G13 and T13 Burke13 200513 Survival13 of young13 razorback13 sucker (Xyrauchen texanus) inrelation to13 stocking rates13 (fishha)13 and13 in the presence13 or absence13 of predatorcommunities in Lake Mohave Arizona-shy‐Nevada13 Pages13 155-shy‐16313 in Proceedings of two13 symposia restoring native fish to the lower Colorado River interaction13 of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 Nevada US Fish and Wildlife13 Service Southwest Region Albuquerque New Mexico

Mueller13 G13 J13 Carpenter13 and P13 C13 Marsh13 200413 Cibola13 High Levee Pond annual report 2004US Geological Survey Fort Collins13 Science Center13 Colorado13 and Arizona StateUniversity Tempe 23 pages

Nesler T P K Christopherson J M Hudson C W McAda F Pfeifer and T E Czapla 2003An integrated stocking plan for razorback sucker bonytail and Colorado13 pikeminnow for the Upper Colorado River Endangered Fish Recovery ProgramAddendum13 to State Stocking Plans Upper Colorado River Basin Recovery13 Implementation Program 12 pp

Papoulias13 D and W13 L Minckley13 1992 Effects13 of foo availability13 on survival and growth13 of larval razorback suckers13 in ponds Transactions of the American Fisheries Society121340-shy‐355

Paukert13 C P D L Ward13 P J Sponholtz13 and K13 D Hilwig13 Effects13 of repeated hoopnetting13 on bonytail chub13 Journal of Freshwater13 Ecology13 20(4) 649-shy‐653

Pfeifer F M13 C Baker13 and M13 Montagne13 199913 Propagation13 facilities13 in the13 Grand Valley13 (24 Road13 Hatchery13 Horsethief13 Ponds and13 grow-shy‐out ponds) for captive rearing of

55

13

endangered13 fishes for the13 Upper Colorado13 River Basin13 Colorado13 River Recovery13 Program FY 99 annual project report Project No 29a13 US Fish and Wildlife Service13 Grand13 Junction13 5pp

Pfeifer F S Seversen and M Montagne 2003 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2003 annual reportProject No 29b13 US Fish and Wildlife13 Service Vernal13 4pp

Rabago-shy‐Castro J L Sanchez13 J G Perez-shy‐Castaneda R and13 Gonzalez-shy‐Gonzlez A 2006Effects of the prophylactic use of Romet-shy‐3013 and13 copper13 sulfate13 on growth13 condition13 and feeding13 indicies in13 channel13 catfish (Ictalurus punctatus) Aquaculture 253 343-shy‐349

Reinitz GL L E Orme and F N Hitzel 1979 Variations of body compositio and growth13 among strains of rainbow trout Transactions of the American Fisheries Society 108204-shy‐207

Ruppert13 J13 B P B Holden13 and P D Abate 1999 Age estimation and growth of razorbacksucker13 Xyrauchen texanus in Lake13 Mead Nevada Proceedings13 of the Desert FishesCouncil 3040

Schnoor K D and J Logan 2002 Operation and maintenance of JW Mumma nativeaquatic13 species restoration facility Colorado Colorado River Recovery Program FY2002 annual project report13 Project No 29d Colorado13 Division of Wildlife Alamosa3pp

Salisbury13 L13 1998 Factors13 affecting razorback13 sucker growth13 in Lake13 Mohave backwaters13 MS Thesis13 Unviersity13 of Nevada13 Las13 Vegas

Schooley J13 D13 and P C13 Marsh13 2007 Stocking of endangerdd13 razorback13 suckers13 in thelower Colorado River Basin13 over three decades 1974-shy‐2004 North American Journalof Fisheries Management 27 43-shy‐51

Severson S H H M Tyus and G B Haines 1992 An evaluation of feeds for raisingrazorback sucker Xyrauchen texanus Journal of Applied Aquaculture 155-shy‐65

Toney D P 1974 Observations13 on the13 propagation13 and13 rearing13 of two13 endangered species13 in a hatchery environment Proceedings of the Annual Conference of the Western13 Association of State Game and Fish Commissions 54 252-shy‐259

Tyus H M13 1998 Razorback sucker13 (Xyrauchen texanus) recovery plan13 University13 ofColorado Center for Limnology Boulder13 76 pages

Tyus H M13 and13 S H Severson 1990 Growth13 and13 survival of larval razorback suckers fedfive formulated diets The Progressive Fish Culturist 52197-shy‐200

56

13

Ulibarri M E 2003 Annual report fiscal year 2001 Dexter National Fish Hatchery13 andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 26 pages

Ulibarri M E 2003 Annual report fiscal year 2002 Dexter National Fish Hatchery andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 59 pages

USBR 2006 Lower13 Colorado13 River Multi-shy‐Species Conservation Program final fishaugmentation plan Boulder City 19 pp

USFWS 2002 Razorback sucker (Xyraouchen texanus) recovery goals Amendment andsupplement to the Razorback Sucker Recovery Plan13 US Fish and Wildlife Service13 Region 6 Denver13 Colorado

USFWS 1999 Annual report 1999 Ouray National Fish Hatchery Vernal 25pp

USFWS 2004 Management plan for the big-shy‐river13 fishes of the13 lower13 Colorado13 river basinamendment and supplement to the bonytail humpback chub Coloradopikeminnow and razorback sucker recovery plans

USFWS13 2005 Station13 profile13 of the13 Dexter13 National Fish Hatchery13 and Technology CenterUS Fish and Wildlife13 Service Dexter

Valdez R A P G Mangan R Smith and B Nilson 1982 Upper Colorado River fisheriesinvestigations13 inW H Miller J J Valentine D L Archer H M Tyus R A Valdezand L13 Kaeding13 editors13 Colorado River Fishery13 Project13 Part 2 Field13 investigations13 US Bureau of Reclamation Salt Lake City Utah

WBNFH 2004 Culture methods of the endangered razorback sucker Xyrauchen texanusUS Fish and Wildlife13 Service Willow Beach National Fish Hatchery13 8 pp

Ward D 2008 Effects of disease treatments on growth of razorback sucker ReportSubmitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 Inpartial fulfillment of work task C10 agreement number 06FG30039

Ward13 D13 M Childs and W Persons 2007 Factors13 affecting13 growth13 of razorback sucker13 (Xyrauchen texanus) in captivity Literature review and knowledge assessmentReport Submitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 In partial fulfillment of work task C10 agreement number 06FG30039

57

Appendices

Appendix 1 Survey Questions Survey of Razorback Sucker Culture in the

Southwestern United States

The enclosed survey is being distributed by the Arizona Game and Fish Department to razorback sucker culture facilities throughout

the Southwestern United States The purpose of this survey is to consolidate information regarding culture of this species so that

appropriate facility improvements can be considered for Bubbling Ponds Hatchery in Arizona Specifically we wish to increase

growth rate and production efficiency at the hatchery Information gathered in this survey will be summarized in a final report to US

Bureau of Reclamation in Boulder City NV and disseminated to all facilities that participate in the survey A workshop to discuss

the findings of this study as well as to share general information concerning razorback sucker culture will be organized by the

Arizona Game and Fish Department at the conclusion of this study and all participants will be invited

Thank you for taking the time to fill out this survey Please contact Mike Childs if you have questions or would like to discuss the

survey

Mike Childs

mchildssedonanet

(928) 639-1346

(928) 634-1279

Facility_____________________________________ Date___________________

Contact Phone _____________________________

ContactPerson_______________________________

Contact Email _______________________________

1 Water quality ranges at this culture facility

Season

Spring (Mar-May) Summer (Jun-Aug) Fall (Sept-Nov) Winter (Dec-Feb)

Temperature (C)

PH

DO (mgL)

PO4 (mgL)

TDS (mgL)

Hardness (mgL)

CaCO3

Pathogens

37

13

Grand Valley13 Native13 Fish Facility13

The Grand Valley Native Fish Facility maintains its own brood stock13 in13 eight13 ponds

located at the Horsethief Basin Wildlife Area in Grand Junction Colorado Fish are

spawned13 on site13 and13 larvae13 are13 reared13 indoors in fiberglass13 tanks13 at the13 24-shy‐Road13 Fish13

Hatchery13 in Grand13 Junction The 24-shy‐Road13 Hatchery13 consists of two13 separate13 recirculating13

systems that operate using de-shy‐chlorinated13 city13 water13 and two13 large13 fluidized-shy‐ bed sand

filters13 and13 rotating-shy‐drum13 filters for waste removal Fish are held in 4-shy‐foot (n=78) or 8-shy‐foot

(n=14) diameter fiberglass tanks Larval fish are started on prepared feeds immediately

after swim-shy‐up and fed exclusively razorback feeds made by Silvercupreg Fish are started on

a 0-shy‐250 micron razorback diet for the first 10-shy‐1213 days13 and13 then13 fed with13 gradually13

increasing13 feed sizes based13 on observations of feeding13 (250 ndash 400 micron 1 starter) Feed

sizes are mixed when transitioning to the next larger feed size These razorback diets are

specially sifted by Dr Rick Barrows (USDA13 Hagerman experiment station Idaho)

Razorbacks13 are13 typically eating 1mm13 extruded pellets by the time they are 35 to 4 inches

in length Fish are fed approximately 70 body weight per day initially and then gradually

reduced to 15 body weight by the time they reach the 300 mm TL target size Fish are

fed seven days13 a week using13 12-shy‐hr13 belt feeders It takes13 12-shy‐16 months to grow fish to the

target13 size in13 the hatchery13

Razorback suckers are sorted after three months and culled to about 4000 fish per

family lot Culled fish are stocked into leased grow-shy‐out ponds Stocking densities for

juveniles in these ponds is based on previous13 stocking and harvest13 rates13 and is pond

specific13 Grow-shy‐out ponds are13 harvested13 periodically13 using Fyke13 nets13 or trap13 nets13 and13 fish of

the target size are stocked Disease problems (Ich Lernea) water quality problems (low

DO) and difficulty in removing all of the fish are challenges for grow-shy‐out of razorback

suckers13 in these13 natural ponds13

Fish reared13 in the13 24-shy‐Road facility are sorted again at four to five months of age into

small and large size groups to obtain more uniform13 growth rates Batch estimates of fish

weight are done every month for each tank A group of fish are weighed and counted to

give an average weight for the tank with lengths estimated based on a lengthweight chart13

The biggest difficulties13 for growing13 out razorback suckers13 at the13 24-shy‐Road13 Fish13 Hatchery13 are13

insufficient space and water flow (oxygen) to grow fish to the target size At the Horsethief

15

13

Basin13 Ponds where broodstock13 are reared13 diseases such as Ich are problematic because

water is pumped directly from13 the Colorado River

Ouray13 National Fish Hatchery13

Ouray13 National13 Fish Hatchery maintains its own broodstock and13 spawns13 fish on-shy‐site13

Larvae are transferred from13 indoor hatching tanks to unfertilized 02 acre outdoor ponds

and stocked at densities 10000 ndash 20000 larvae13 per13 pond13 Even13 though13 outdoor13 ponds13 are13

covered with13 bird13 netting13 avian predators13 still get caught in the13 nets13 if they13 can see fish

Ponds are dyed blue13 as the13 fish grow to13 prevent avian predation13 While in the outdoor

ponds13 fish13 are13 fed a slow-shy‐sinking salmon diet made by Silvercupreg twice daily by hand

Amount of feed is based on periodic sample counts Fish are grown until late September at

which time temperatures require that all fish13 other13 than13 adult broodstock13 be13 brought

inside for the winter Ponds are drained completely and fish are sorted by hand Fish that

have reached the target size (300 mm TL) are stocked into the Green and Colorado Rivers

All remaining fish are moved indoors13 and13 held13 in three-shy‐foot (n= 30) or eight-shy‐foot (n=27)

diameter circular tanks On average it takes 12 ndash 18 months to grow fish to the 300 mm TL

at Ouray13 hatchery13

Razorback suckers are held during the winter in a recirculating system13 that

operates13 using13 two13 large13 fluidized-shy‐bed sand filters and a rotating-shy‐drum13 filter for solids

removal Fish are fed the Silvercupreg razorback diet using belt feeders There is currently

capacity13 to13 hold13 only13 20000 200-shy‐300 mm TL fish inside the facility and any extra fish13 are13

stocked13 into13 floodplain-shy‐wetlands or used for research purposes13 Ouray no longer leases

any private grow-shy‐out ponds Grow-shy‐out ponds were troublesome due to poor water quality

harvesting13 difficulties13 and13 non-shy‐native13 fish introductions13 The biggest difficulty13 for

production13 of razorback13 suckers at the Ouray13 National13 Fish13 Hatchery13 is space13 during13 the

winter to maintain large numbers of fish and high iron and manganese in the well water

that must be filtered out prior to use

16

13

Willow Beach National Fish Hatchery13

Willow13 Beach National13 Fish Hatchery receives wild-shy‐caught larvae from13 Lake

Mohave Larvae are treated for diseases with formalin and malachite green and placed in

45 ten-shy‐gallon13 flow-shy‐through aquaria13 Recirculated13 solar heated water13 22-shy‐25deg C is used to13

allow production of warm13 water fish at this traditionally cold water facility (Figiel 2003

Figiel et al 2005) Fish are fed brine shrimp nauplii to satiation every hour and after 14

days small amounts of specialized larval fish diet (Encapsulon13 Cyclopeeze13 spirulina13 and

artificial plankton) are introduced After 30-shy‐6013 days13 fish are13 transferred13 to13 six13 32-shy‐gallon13

fiberglass troughs at densities of 1000 to 1500 fish per tank and then a month later moved

outside13 to13 eight recirculating13 raceways that use a combination of well water and solar-shy‐

heated water to maintain temperatures of 22 ndash 25deg C during the summer months

When13 in13 the outside raceways13 fish are fed the razorback13 diet13 using13 belt13 feeders and

fed by13 hand13 at 10 -shy‐ 70 body13 weight per13 day Feed amount is adjusted based on sample

counts according to a feed conversion program13 developed for razorback suckers by Willow

Beach Hatchery personnel This program13 uses length and number-shy‐per-shy‐pound generated

from13 several years of razorback growth data (Figure13 1) Fish are13 sorted13 opportunistically13

and are not handled during the summer months when water temperatures are above 20degC

In 2004 the target size for stocking was 325 mm TL or greater (WBNFH 2004) with a

target13 of producing13 6000 fish per year Reaching this13 target size usually13 takes13 two13 growing13

seasons13 The biggest difficulty13 in rearing13 razorback suckers13 at Willow Beach13 National Fish

Hatchery13 is insufficient space13 to13 grow fish to13 increased13 target sizes (400-shy‐500 mm TL)

Uvalde13 National Fish Hatchery13

Uvalde13 National Fish Hatchery13 in Texas13 receives 35000 ndash 60000 razorback sucker13

fry annually in MarchApril from13 Dexter National Fish Hatchery The fry are acclimated in

bags submerged in the pond for a minimum13 of one hour and released into13 a 1 acre13 fertilized13

pond where they are reared for the remainder of the summer Fingerlings are fed a starter

razorback diet when they reach approximately 50 mm TL In AprilMay the previous year

class of razorbacks are captured from13 their over-shy‐wintering pond enumerated graded and

split into13 one-shy‐acre grow-shy‐out ponds Approximately 4000 ndash 5000 fish will be13 placed13 in each13

one acre pond for summer grow-shy‐out Fish are reared for approximately 150 days (May ndash

17

13

Oct) and fed the Bozeman razorback diet two times a day five days a week at 15 ndash 30

body weight per day based on average water temperature

Figure 1 Relationship between length and number of fish per pound

In general13 juvenile razorback13 suckers (received as fry13 during13 the previous spring)13

reach the target size of 300 mm TL in approximately 6 months In 20062007 Uvalde

produced 6000 razorback suckers 300 mm TL for introduction into the San Juan River

Starting13 in 2008 Uvalde NFH will be producing13 and distributing13 12000-shy‐ 300 mm TL

razorbacks for stocking into the San Juan River Predation from13 migrating cormorants has

occurred but timing of harvest and over wintering protection methods such as covering

ponds with netting or placing fish indoors helps to minimize losses during the cormorant

migration (November to March) Uvalde has experienced razorback mortalities because of

bacterial problems but these are usually resolved through the use of oxytetracyline

medicated feed

Overview13 of Differences in Culture Methods

Several differences were noted when conducting surveys at each of the five main

production facilities for razorback sucker (See Appendix 3) These differences include

different stocking13 and13 rearing13 densities13 (Table13 4-shy‐5) various feeding regimes and type of

18

13

lt=amp

feeds (Table 7) as well as differences in grading or sorting practices Some of these

differences are13 related13 to13 whether13 or not razorback suckers13 are13 being13 reared13 in extensive-shy‐

culture13 facilities13 (ponds) or intensive-shy‐culture13 settings13 (raceways13 o tanks)13 Some13 practices13

are unique to a single facility13 or a couple of facilities (Table 6)13 Managers at each facility13

were asked to identify the biggest13 difficulty or constraint13 that13 they experience when13

growing-shy‐out juvenile13 razorback suckers13 at their13 respective13 location13 Space constraints13

water quality and disease problems were the main factors limiting production of razorback

suckers13 at these13 facilities13 (Table13 8) Calculated or reported growth rates from13 the literature

vary widely (Table 9) and range from13 02 to 18 mmday These growth rates indicate that

juvenile razorback suckers have a very high growth potential under optimal rearing

conditions13

Table13 4 Stocking13 densities13 for larvae13 and13 fry in ponds

$amp( )(+amp-( 01-2(3(4amp56( 4amp56(+amp-( 01-2782-( $amp () + --amp +amp0amp)+amp 12-3amp ( )+amp0amp+amp --amp +amp0amp)+amp 42556789amp8 ( +amp0ampgt+amp 3amp +amp0amp+amp A-BC-Damp (E + 3amp )+ F-6ltamp ) G+ 3amp G+

Table13 5 Rearing13 densities13 at intensive13 culture13 facilities13

$amp( )amp+(($-( $0( 12(3$+( 40((amp05( 67((amp05( 8$9(407$( $amp amp())amp++-$amp 0 1 0amp2amp1amp 3amp2amp4 0544

6amp())amp++-$amp 610 021 4amp2amp47amp 3amp2amp77amp 058 9$amplt+)amp 4amp())amp++-$amp 00 1 7amp2amp77amp 851amp2amp0amp 05

6amp())amp++-$amp 610 77amp2amp1amp 0amp2amp1amp 053

19

13

Table13 6 Rearing13 practices13 that are13 unique to13 specific rearing13 facilities13 $$amp( )$+-(amp$-(0(1-amp2034( $amp()amp+( -0$(12(33+(amp(amp134$53+(amp$amp3+(6amp+(

723(843(1$8(422(6amp+(42amp(4(423(19$43( 343( lt34$53(6amp+(6(4($03(amp4+94amp(842($1$1(63$$34(amp+(63626243( =amp+(gtamp94ampA( B3(1(1$+53+C3+(amp+(1$43(1(3D0$(1(amp443(amp+(amp443( 734231(amp( B3(1(193(44(1(34amp(amp(+49E(6amp+( -E3(F3+( G3amp(1(12(amp(H3(13$(4ampE(C(IJK($$amp( A( L43(+A3(4(6303amp4(63+4ampM(66$3D3amp4$(34amp(amp(6amp+(C((4amp3( L$$8(392(

B0$+3(

N43D(13+(4($0$(12M(amp+(639$53+($0$(12(+34( G3amp(12(amp(399$4amp(4+(938A(842($(2343+(843( N443D643+(3amp(12(amp(amp34(63amp(amp(423(O$+(G03( )amp+(3(134$53+(6(4(39364(1(1A(4(44(423D(amp((D3(amp4$(+34(

Table13 7 Types of feed used at razorback sucker13 hatcheries13 $amp ()amp+-amp0- $$)1amp23 45-amp)-$5)1amp23 $amp()amp+( -amp$amp+(amp+( -amp012$3+(amp+4(amp5215$(0+( 65ampamp7(85209(+2($1(87((15315lt=(+2(

+amp+amp(amp(55$5$2gt( 21( Aamp+(amp+( )amp+(012$3+(B29(5$05$95($$2(5amp+(

199524(amp5215$(0+( 65ampamp7(85209(+2($1(87(15315lt=(+2(amplt( 29gt(51($51(amp9(2(25=(C(DD(0+(

E15amp+(Famplt2amp( G1$5(lt1lt$51(25amp=( HIJKH(Dlt1amp(15315lt=(+2(I(C2(CH(+5gt( )11$gt($511(02+(15315lt=(+2(

$1(87(15315lt=(+2(D5$$(3(lt5$$gt(02+(gt( 6lt=(511B(

L15gt( G1$5(lt1lt$51(25amp=(Aamp+( amp+(

HIJKH(Dlt1amp(15315lt=(+2(I(C2(CH(+5gt( )11$gt($511(02+(15315lt=(+2(

$1(87(15315lt=(+2($1(87($B(amp=amp( 5$Damp(+2(

M$$B(5lt9(-5$+( NO515(G1$5(219( L2+1(15ltB5gt(Aamp+(5amp+( amp$amp+(amp+(

1amp(91D(amp5$(Pamplt5$amp4( 8gtlt$34(1$amp54(5amp+(5120lt5$( $5amp=2amp()amp+(012$3+(B29(5$05$95( $$2(5amp+(19952Q(amp12152( 1+lt2amp(

$1(87(15315lt=(+2($1(87(15315lt=(+2( $1(87(15315lt=(+2(

Table 8 Factors limiting production at major razorback sucker facilities

$amp( )amp+(-0+1((2$(0amp1ampamp(-34amp( $amp()amp+( -(01$2(34+(546(amp(0amp(01amp(541(13( -741( 803(3amp41amp4(9((+ltlt1amp4(03(amp(44amp(2=(4(

+ltlt3$4(4(2amp4amp(014(1gt13=(43=( 1amp+(amp34amp( 803(3amp41amp4(1$4+(4(541(A$4B(amp+(+$C+(

7Bamp($244amp(lt(1313$4amp(B42( D1B( E41(A$4B(01$2(3+(B(66(1amp(amp+(2ampamp(

Eamp41(420141(464(1A1($$(lt6(4((2C+(amp+1( 803(3amp41amp4(1$4+(4(541(A$4B(amp+(+$C+(7Bamp(

E$$5(36( 803(3amp41amp4F(15amp(lt6(4(amp31amp$B($11(gt( 1$4(amp(ampltlt3amp4(03(amp(44amp(lt1(amp5(lt6(

GC$+( 8221(420(3amp(4(6691A1amp(051((4(410$(+(4( 661(1amp+541(020amp(4(=0(0amp+(3$F(

20

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Table9Reportedandcalculatedgrowthratesfromtheliterature

Calculatedgrow

thratesbasedon

informationprovidedinliterature

aApproximationsofmaximum

grow

thpotential(basedon

average13 maximum

sizesiffishreportedatharvest

21

13

General Information on Factors that Affect Fish Growth

Growth in fish is extremely variable and is impacted by many different

physiological and environmental factors Growth rates are known to change with size and

age sex season activity level density amount13 of living space quality and quantity of food

genetics and temperature (Brett 1979) Growth experiments conducted at different times

of year can result in growth rates that are not comparable As fish become larger their

physiological13 potential to grow decreases making determination of growth rate dependent

on the size of the starting fish and the length of the experiment (Busacker et al 1990)

Genetic factors also have great potential to influence growth rate Some species have

strains13 and13 races13 that display vastly different growth potentials (Reinitz et al 1979) All of

these factors combine to make assessment of the individual factors controlling fish growth

difficult13

Water temperature is probably the most important variable affecting growth rate13

All of the basic functions that affect growth such as feeding digestion and metabolism are

temperature-shy‐dependent13 Growth13 is inseparably13 tied13 to13 bioenergetics13 and13 therefore13 also13

tightly tied to temperature When temperatures are below optimum daily temperature

fluctuations can stimulate growth Photoperiod is also commonly linked to water

temperature and can influence growth rates in fish (reviewed in Brett 1979)

Fish density13 is known to13 affect growth13 and13 can alter13 growth13 rates13 in several ways13

Fish that exhibit strong territorial behaviors13 or natural schooling tendencies13 will

experience reduced growth if densities are too high or too low (Brett 1979) Dominance

hierarchies where some fish feed more aggressively than others can also lead to high

variability13 in growth13 rates13 (Koebele13 1985) Crowded13 conditions13 also13 cause physical

interference13 between13 fish and13 poor water13 quality13 which13 reduces13 growth13 (Busacker13 et al13

1990) The effects of fish numbers space and feeding opportunity are frequently correlated13

and often13 difficult13 to distinguish (Brett13 1979)13

It is impossible to study the effects of environmental factors on growth without also

evaluating feed rations (Brett 1979) Amount of food quality of the diet particle size

number of feedings per day and time of feeding have all been shown to affect growth

(Busacker et al 1990) In controlled laboratory studies food is usually fed ad libitum13

22

13

(constantly available) and other variables are altered to assess impacts of environmental

factors13 on growth13 These studies13 are13 usually13 conducted13 in tanks13 or raceways13 because13

researchers must verify that food is constantly available to the fish which is difficult to do

in large pond environments where the fish and the bottom13 are often not visible (Busacker13

et al13 1990)

Specific Information13 o Razorback13 Sucker13 Growth

Variable13 growth

Growth in razorback suckers is naturally highly variable and may be a function of

their evolutionary history (USFWS13 2002)13 Minckley (1983) speculated that13 wide size

variation in a single cohort of razorback suckers may be adaptive with fast-shy‐growing13 fish

that13 reproduce at a young13 age surviving13 better in13 high discharge years and slow-shy‐growing13

smaller fish surviving better during drought periods This highly variable growth rate

makes rearing razorback suckers in a production setting difficult because fish from13 a single

cohort do not reach the target stocking size simultaneously One of the major tasks for

aquaculture is to maximize both individual growth and total production13 (Gerking13 1978)13

This becomes more difficult when the species being cultured exhibits highly variable

growth13 rates13 because of genetic influences as is the case with razorback13 suckers13

Razorback13 sucker growth13 is typically very13 rapid13 during13 the first13 year of life13 and then13

declines with age First year growth can be as low as 50 mm and as high as 350 mm (Valdez

et al13 1982 Minckley13 1983 Mueller13 1995) Razorback sucker13 grow rapidly13 for

approximately the first five or six years of life and then growth slows13 (McCarthy13 and13

Minckely 198713 Tyus 199813 Minckley et13 al 1991)13 Growth of older individuals in13 extant13 wild

populations is very13 low (Minckley 198313 Tyus 198813 Modde13 et al 1996)13 Wild growth13 rates

for mature adult fish in Lake Mohave based on PIT tag recaptures were often too small to

be accurately measured for both males and females over the time period of 1987-shy‐199713

(Marsh and Pacey 1998) This information suggest it will take substantially longer to rear

fish to13 increasingly13 larger13 stocking13 sizes (40013 ndash 500 mm TL) than it did to reach the target

size of 300 mm TL

Growth in ponds

23

13

One of the main strategies for maintaining genetic refugia and self-shy‐sustaining13

populations of razorback13 sucker in the lower Colorado13 River basin13 is to rear razorback13

sucker13 larvae13 in production13 ponds until they13 are13 a suitable13 size for stocking13 (USFWS13 2004)

Pond culture has proven useful to promote rapid growth of juvenile razorback suckers

(Kaeding and Osmundson 1989) Marsh (1994) reported that growth rates of razorback

suckers13 reared13 in golf-shy‐course13 ponds exceeded13 the13 best growth13 rates13 obtained13 under

intensive13 culture13 conditions13 at federal hatcheries13 especially13 during the13 first several years13

of life Growth rates in these semi-shy‐natural ponds are also comparable to estimated growth

rates13 of juvenile13 wild13 fish (McCarthy13 and13 Minckley13 1987) Modde13 and13 Haines13 (2005)

reported13 the13 greatest growth13 rates13 in the13 largest and13 deepest floodplains13 with13 the13 greatest

amount of submergent vegetation but excellent growth and survival of fish in a grow-shy‐out

pond is of little value if there is not an efficient way to collect the fish from13 the pond

(Kaeding and Osmundson 1989)

Temperature13

Bulkley and Pimentel (1983) used shuttle boxes in the laboratory to determine a

temperature preference13 for razorback suckers13 of 23-shy‐24degC13 In13 their13 studies13 razorback

suckers were found to avoid temperatures below 118 degC or above 286 degC Razorback

suckers at Bubbling Ponds Hatchery are more active in the spring and feed better as

photoperiod increases even prior to water temperatures rising (Frank Agygos personal

communication) Table 3 briefly summarizes water temperature data from13 each facility

Detailed seasonal water temperature profiles are not currently available for many

razorback grow-shy‐out sites13

Density13

Extensive studies have been conducted on commercially important species to

evaluate stocking densities and feeding rates that maximize production For these species

controlled experiments under laboratory conditions have established relationships

between temperature density and feed ration on growth (Brett 1979) but this information

is sporadic13 or non-shy‐existent for razorback suckers13 (Bays13 et al13 2005) Fish culturists13 with13

24

13

experience13 rearing13 razorback suckers13 typically13 have13 target stocking13 densities13 that13 they use

(Tables13 4 -shy‐ 5) These stocking densities have largely been determined over time by trial

and error These approximate stocking densities provide a good starting point for more

controlled13 types13 of replicated13 pond studies13

Feed ration

Razorback13 suckers are currently13 being13 fed a wide variety13 of prepared diets (Table 7)

that range from13 a slow-shy‐sinking salmon feed manufactured by Silver Cupreg to a spirulina

and krill-shy‐enhanced catfish feed made by Rangenreg Most locations are feeding 20 ndash 50

body13 weight per13 day13 Methods13 for culture13 of razorback sucker13 larvae13 in intensive13 settings13 at

fish hatcheries are well documented (Figiel 2005) and various larval fish diets have been

evaluated13 (Tyus and13 Severson 1990 Severson et al13 1992) but no standardized13 procedures

are used for feeding13 larval13 fish in13 intensive settings13

Razorback sucker larvae are also effectively reared in pond environments using

natural foods supplemented with larval fish diets and survival is high when no predators

are present13 (Mueller 2006)13 Growth rates for larval13 and early juvenile razorback13 suckers

may increase with pond fertilization Diet and physiological studies on wild razorback

suckers indicate that they feed on plankton as well as benthic organisms during their entire

life (Marsh 1987) Artificially fertilizing ponds may greatly increase production capacity

and growth rates for razorback13 sucker (Papoulias and Minckley13 1992) and warrants

further13 investigation13

Handling stress

Handling stress13 has13 been shown to13 influence growth13 rates13 Paukert13 et al (2005)

found that growth of bonytail chub was reduced by 26when compared with controls

after being13 repeatedly13 captured and handled in13 hoop13 nets13 Handling13 effects are likely13 to be

similar for razorback suckers that are repeatedly13 captured and sorted in13 a hatchery13 setting13

Razorback suckers that are handled at Willow Beach National Fish Hatchery will commonly

not eat for two weeks after handling (John Scott personal communication) This creates a

difficult situation13 for production13 facilities because13 fish13 need to be sorted to ensure13 large13

25

13

aggressive fish do not interfere with growth of smaller individuals but frequent handling

and sorting13 causes stress related reductions in13 growth13

Measuring Growth in Captive Fish

Weight is the traditional measure used to estimate growth or production in

aquaculture settings13 Groups of fish are typically13 weighed and an average individual13 weight13

is computed (Busacker et al 1990) Although this method is often logistically the easiest it

may not be the most informative for species with highly variable growth rates like

razorback suckers especially when target lengths must be reached before fish can be

stocked Weight can also be highly influenced by things like stomach fullness or

development of gonads (Busacker et al 1990) Condition factor or relative weight can also

be used to assess growth of fish but these tools may be more robust predictors of fecundity

than of growth (Anderson and Neuman 1996) For some species sexes need to be

distinguished because males and females may differ in morphology (Anderson and

Neumann 1996) Mueller (2006) analyzed growth rates based on PIT tag recaptures of 86

razorback suckers13 in High13 Levee Pond13 and13 found13 that differences13 in growth13 do not appear13

to occur until fish are over 450 mm TL at which time growth rate in males slows while

females continue to grow at a slightly higher rate This would indicate that sex may not be

an important factor to consider when examining growth rates unless the target grow-shy‐out

size is above 450 mm TL

The best measures of growth are often determined from13 the length and weight of

individuals rather than from13 groups of fish (Anderson and Nuemannn 1996) because

individual growth rates give better estimates of confidence and variance (Busacker et13 al

1990) Length frequency analysis or recapture of previously marked individuals of a known

size is likely to yield the most useful information for razorback sucker growth The success

of any of these methods depends on proper sampling procedures that are representative of

the population as a whole (Busacker et al 1990) Sampling methods that are known to be

size-shy‐biased such as trammel nets (Mueller et al 2004) or cast nets should not be used when

trying to measure growth rates13

26

13

Conclusions

For razorback sucker survival is largely associated with stocking size Additional

focused13 research13 is therefore13 needed to13 identify13 ways13 to13 increase13 growth13 rates13 of captive-shy‐

reared13 razorback sucker Growth13 rate13 in fish is controlled13 by many factors including fish

size and age temperature density and feed ration which can all be highly correlated

Growth of razorback suckers is also inherently variable which makes the task of identifying

the key factors that13 affect13 growth in13 captivity even more difficult The focus at most

razorback rearing facilities13 is production so the13 types13 of data that are13 collected13 are13 often

insufficient for detailed13 evaluations13 of individual rearing13 practices13 on growth13 Surveys of

existing13 razorback sucker13 rearing facilities indicate that culture methods vary widely and

the types of growth data13 that13 are collected are not13 standardized13 Replicated studies with

detailed information on rearing location water temperature initial stocking size stocking

density and the sizes of all fish at harvest are needed in order to compare the effects of

individual rearing practices on growth This type of research will ultimately provide both

time and cost-shy‐savings to production facilities by reducing the amount of time necessary13 for

razorback sucker to reach stocking size improving overall production efficiency

Optimum13 rearing densities for razorback sucker larvae and juveniles remain to be

determined Current stocking densities will be very useful as starting point for more

detailed studies and although optimum13 rearing densities are likely to be site-shy‐specific13

replicated studies on density will provide a valuable reference for hatchery managers

Frequency13 of sorting is another13 area that needs13 further13 research Frequent

handling13 and13 sorting13 can13 cause13 stress-shy‐related13 reductions13 in growth but not sorting can

create dominance hierarchies that further reduce growth rates of subordinate individuals

The effects13 of sorting13 on overall fish growth13 in both13 pond and13 intensive13 culture13

environments warrant further investigation Research techniques for these types of

experiments are well understood and typically utilize a matrix of replicate ponds per

variable (Bays et al 2005) In every case accurate and complete records of sampling

procedures and data collection are needed in order to interpret data and make inferences

about13 growth rates (Busacker et13 al 1990)13

27

13

Additional research is also needed to evaluate long-shy‐term13 survival of stocked fish

reared in ponds compared to fish13 reared13 in intensive13 culture13 facilities13 Exercise13

conditioning13 and predator-shy‐recognition training may also increase survival of stocked fish

and be more economically feasible than rearing fish to increasingly larger sizes prior to

stocking13 The success13 of traditional fish hatchery programs is measured largely by the

number of fish stocked but hatchery programs for endangered species must measure

success in terms of long-shy‐term13 survival and species recovery (Brannon 1993 Anders 1998)

A specific list of research recommendations follows

Specific Research13 Recommendations13

bull Use replicated studies13 to establish optimum stocking13 densities13 for ponds13 and

tanks13 that can be used as13 a starting13 point for site specific refinement

bull Determine if sortinggrading13 improves13 overall growth rates13 in both ponds13 and

intensive culture facilities13

bull Investigate the use of artificial fertilizers13 to improve growth of both juvenile

and adult razorback suckers13 in ponds13

bull Determine if the razorback sucker diet gives13 better growth rates13 than cheaper

catfish or salmon feeds

bull Evaluate growth rates13 and production potential of new intensive culture

methods13 such as13 large circular tanks13

bull Evaluate13 long-shy‐term survival of fish produced from raceways13 and circular tanks13

compared to fish reared in ponds13

bull Evaluate more effective means13 of treating13 fish diseases13

bull Evaluate factors13 other than size that may increase post-shy‐stocking13 survival such

as13 exercise conditioning13 predator recognition training or rearing13 under more

natural settings13

28

13

II The Effect of Disease Treatments on Razorback Sucker

Growth

Section13 SummaryFormalin copper sulfate potassium permanganate and13 salt are all chemicals commonly13 used13 to13 treat13 Ichthyophthirius multifiliis outbreaks in captive razorback sucker (Xyrauchen13 texanus) Weexposed 190 juvenile13 razorback suckers (127 ndash 26 mm TL) to13 5 5-shy‐day treatments with13 each13 chemical to evaluate the effects13 these chemicals13 may have on growth Fish grew an average of23513 mm TL13 during the month13 study period Fish treated with formalin grew on average13 29mm TL (03 mmday) while fish treated with copper had the lowest growth averaging 20 mmTL (021 mmday) No significant differences in13 growth were observed among fish treatedwith any of the chemicals compared to untreated fish (pgt005) Reductions in growth13 as aresult of repeated chemical treatments are not likely the cause of differences in growth ratesamong13 facilities that raise razorback suckers Repeated chemical treatments may13 have otherimpacts to overall13 fitness or long-shy‐term survival but13 these effects were not13 evident13 in our study

29

13

Introduction

Preservation13 of razorback sucker13 (Xyrauchen texanus) currently13 depends on captive13

rearing and stocking programs until permanent solutions to factors that prevent wild13

recruitment are found Low survival of stocked razorback suckers (Brooks 1986 Marsh

and Brooks 198913 Marsh and Pacey13 2005) has caused target13 sizes for stocked fish to

steadily increase in efforts to reduce predation mortality (Marsh et al 2005 Schooley and

Marsh 2007) Rearing fish to larger sizes at hatcheries comes with increased costs and

creates the need to evaluate husbandry and rearing practices that may affect fish growth

Formalin copper sulfate potassium13 permanganate and salt are all chemicals

commonly used at razorback sucker rearing facilities to treat outbreaks of the protozoan

parasite13 Ichthyophthirius multifiliis ldquoIchrdquo is one of the most pathenogenic diseases of

cultured13 freshwater13 fishes (Matthews13 2005) and causes large13 losses in captive13 populations13

of endangered razorback sucker Each of these chemicals used to treat Ich only kill the free-shy‐

swimming life stage of the parasite13 requiring13 repeated doses over several13 days depending13

on water temperature These chemicals treatments are needed to prevent loss as a result

of disease outbreaks but the cumulative effects repeated disease treatments have on

growth13 are13 unknown

Copper13 sulfate13 has13 been shown to13 significantly13 reduce13 growth13 of channel catfish13 in

production13 ponds (Rabago-shy‐Castro13 2006) but it is unknown whether13 razorback suckers13

experience similar reduced growth following copper treatment Quantifying the impacts of

disease treatments on growth will help to interpret the wide differences in growth rates

observed13 at various13 razorback sucker13 production13 facilities13 throughout the13 southwest

(Ward et al 2007) If one chemical is found to have less detrimental impacts on growth

than another then it may be preferred for use as a disease treatment We evaluated growth

rates13 of razorback suckers13 under13 replicated13 and13 controlled13 conditions13 to13 assess13 effects13 of

repeated formalin copper sulfate and potassium permanganate and salt treatments on

growth13

Methods

We captured 190 juvenile razorback suckers from13 ponds at Bubbling Ponds Fish

Hatchery AZ using hoop nets or cast nets All fish were of the same age class and

30

13

averaged 179 mm total length (TL) (range13 = 127 ndash 262 mm TL)13 These fish were13 offspring13

of captive13 razorback sucker13 broodstock held13 at Dexter13 National13 Fish Hatchery13 NM13 (2007

year class) All fish were tagged with passive integrated transponder (PIT) tags and

quarantined for one month prior to the experiment to allow fish to recover from13 tagging

and become accustomed to being held in circular tanks

At the beginning of the study all fish were weighed measured and scanned for

individual tag numbers with 19 randomly selected fish placed into each13 of 10 8-shy‐foot

diameter circular tanks (Figure 2)13 Each13 tank contained13 two13 airstones13 and13 an13 individual

biofilter with a recirculating water pump (31 litersminute) that had been operating for

at least 1 month prior to the experiment to allow bacterial colonies to become

established Two tanks were designated as a control and did not receive any chemical

treatments while the other eight tanks received formalin copper sulfate potassium13

permanganate or salt treatments at two week intervals (two tanks per chemical

treatment) Formalin copper sulfate and potassium13 permanganate were treated at 1 part

per million (ppm) and salt was applied at 30 parts per thousand (ppt) These treatment

rates are commonly used to treat13 razorback13 suckers for ich at Bubbling13 Ponds Fish13

hatchery (Frank Agygos personal communication)

Figure 213 Photo ofexperimental tankswith individualbiofilters and aeration

31

13

Each treatment consisted of a series of doses applied on Wednesday Thursday and

Friday with a 90water change between each dose Biofilters were removed from13 all

tanks and held in a separate holding facility during treatments and then replaced on the

Monday following treatments after a 90water change This schedule allowed fish to be

exposed to chemical treatments for 5 consecutive days without water quality deteriorating

This 5-shy‐day chemical treatment was repeated every two weeks from13 July to October (97

days)13 for a total of 5 5-shy‐day treatments Water temperature in the treatment tanks ranged

from13 13degC (55degF) to 32degC (91degF)

Fish were fed a fixed ration of commercial razorback diet (Silvercup 4mm13 pellet)

once daily13 (2 percent body13 weight per day13 as calculated13 by13 average initial fish weight)13

At the end of the experiment all fish were again weighed measured and scanned for

individual tag numbers Growth of fish in each treatment group was compared using

analysis of variance (ANOVA) Any mortalities13 that occurred during the13 study13 were13

replaced with previously quarantined fish of equivalent size to maintain equal densities in

each13 tank13 but growth13 data was13 only13 recorded for fish which13 survived13 the13 entire13

experiment

Results

Fish at the13 start of the experiment averaged 179 mm TL (Range13 = 127 ndash 262 mm)

with no significant differences in fish length among treatment groups (F(4189) = 00183 p

gt 0999 ANOVA) On average fish grew 235 mm TL (024 mmday) during the 3 month

study13 Fish in tanks13 treated with formalin had the highest growth averaging 29 mm TL (03

mmday) while fish in tanks treated with copper had the lowest growth averaging 20 mm

TL (021 mmday) Fish in the control tanks averaged 213 mm TL in growth (022

mmday) (Figure13 3)13 Formalin-shy‐treated fish grew13 significantly faster than13 any other

treatment group but no13 significant differences in growth13 in length13 or weight were13

observed among fish treated with any of the chemicals compared to untreated (control)

fish (pgt005 ANOVA)

32

13

Figure 313 Average growthof razorback suckersexposed to a series of 5 5-shy‐day chemical treatmentsover a 97-shy‐day13 periodError bars representstandard error

Discussion13

Growth13 rates13 observed13 in our study13 (021 ndash 03 mmday) are low compared to those

reported13 in other13 studies13 of razorback sucker13 growth13 (0213 ndash 18 mmday) (Ward et al

2007) Using recirculating water systems for our study required filters to be removed and

replaced during treatments Stress to fish caused by removing and replacing filters within

the tanks as well as repeated water changes may have led to overall higher stress and

reduced growth rates compared to those reported for unconfined fish Growth in fish is

highly variable and is affected by many different physiological and environmental factors

including fish size density temperature amount of space and food (Brett 1979) We

strived to control each of these factors but other factors may have also influenced growth

in our experimental tanks During mid-shy‐summer water temperatures in the treatment

tanks reached 32degC (91degF) At these warm13 temperatures fish are very susceptible to

bacterial13 infections13 The slightly higher growth exhibited by fish in the formalin and

potassium13 permanganate treatments may have been the result of these two chemicals

33

13

being effective at controlling bacterial infections The differences in growth we measured

among treatment groups were not statistically significant and do not appear13 biologically13

meaningful during the relatively short duration of this study (97 days) although the

cumulative effects of slightly reduced growth could be biologically meaningful over longer

time frames

Reductions in growth13 as a result13 o repeated chemical treatments are not likely the

cause of differences in growth rates among facilities that raise razorback suckers

Repeated chemical treatments may have other impacts to overall fitness or long-shy‐term13

survival but these13 effects13 were13 not evident in our study It is more likely that the parasite

outbreaks themselves are the cause of different growth rates among razorback rearing

facilities rather than the chemical treatments used to treat the parasites We recommend

that hatchery managers continue to use the chemicals that are most effective at controlling

ldquoIchrdquo13 at their individual13 facilities

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower Colorado Rive Multi-shy‐species13

Conservation Plan under Work Task C10 We thank Ty Wolters and Tom13 Burke for their

support of this research and Frank Agygos and Dave Billingsly of the Bubbling Ponds Fish

Hatchery13 for their13 technical assistance13 and13 help with13 collecting13 fish

34

13

III13 Razorback Growth Rates at Bubbling Ponds ndash 2009-shy‐2011

Section13 SummaryExperimental studies at Bubbling Ponds Fish Hatchery AZ have strived to understand

factors that affect razorback sucker growth in captivity and identify ways to improve growthrates and maximize size at release Rather than performing experimental studies that wouldrequire major13 rearrangement (and likely reduced production)13 of hatchery operations our13 studies13 used normal variation in production techniques13 and practices13 to isolate factors13 thatmay modify growth rates

Our initial work identified razorback13 growth rates in13 lined ponds at standard fishdensity as 026 to13 028mmday (789 to 843 mmmonth) No significant differences in growthrate were observed among fish that had been in the pond only during the winter13 periodcompared to fish that had been in the pond the entire year indicating that water temperatures13 at Bubbling Ponds are high enough to allow fish to incorporate feed effectively year-shy‐roundHowever these growth rates are lower than most values reported from the literature fromnatural or semi-shy‐natural pond environments No significant differences in13 growth rate wereobserved13 between large and13 small fish13 within the 150 ndash 29 mm TL13 size range Additional worksuggests13 that razorback suckers13 tagged at over 300 mm TL had reduced growth rates (024mmday 73 mmmonth) as would be expected according to a typical Von13 Bertalanfy growthcurve although growth rates13 were only slightly less13 than the average growth rate for thehatchery (027513 mmday 82513 mmmonth)

Sorting13 to13 separate small fish from large fish after the first year of growth is practicedesigned13 to allow smaller fish to ldquocatch uprdquo to larger fish We found that13 this technique doesappear to13 improve growth rates of smaller fish Growth rates of sorted small razorback suckers(029 mmday 87mmmonth)13 were equal to that13 of larger13 fish (028 mmday 8413 mmmonth)indicating that sorting may have helped to offset their original slower growth trajectory

Bubbling Ponds Fish Hatchery grows razorbacks in 6 long deep ponds lined with heavyplastic 2 long deep13 earthen13 (unlined) ponds and three wide shallow earthen ponds The wideshallow ponds13 have historically produced very large fish at low density but have been found tomaintain much lower fish numbers than deeper ponds We found13 that growth13 rates ofrazorbacks kept at high density (4-shy‐700013 fish)13 in a wide shallow pond grew extremely slowly(024 mmday 726 mmmonth) This growth rate is among the slowest of any fish over theyears of our study and demonstrates that13 though the large ponds may produce large fish at lowdensity13 they are unable to overcome high13 fish13 densities

Finally one of the major factors influencing13 fish13 growth13 in hatcheries is disease onemajor summer-shy‐time disease at13 Bubbling Ponds is the ectoparasite Ich (Ichthiopthirusmultifiliis) To investigate the impact Ich has on razorback growth we eradicated fish from thespring and water conveyance ditch that supplies13 water to the hatchery using Rotenone This13 restoration effort was fairly short-shy‐lived (Ich returned to the hatchery within four months) but

35

13

growth13 rates of fish13 reared for four months without Ich present (031 mmday 92 mmmonth)were significantly higher than the following 8 months of growth for those same fish (022mmday 65 mmmonth) This disease-shy‐free growth rate is in fact faster than any13 otherprevious growth rates observed at the hatchery in our study

We conclude that growth rates at the Bubbling Ponds Fish Hatchery are likely as highas possible given the pond densities required to13 meet production goals and the Ich-shy‐infestedwater13 that feeds the facility Sorting practices are successful in helping as many fish as possiblereach stocking length as fast as possible Unlined ponds may be able to grow large fish at lowdensities but whatever factors allow for that growth13 are not able13 to overcome13 high fish densityThus the large lower ponds at Bubbling Ponds may be better utilized via renovation to13 deepenand line them

Disease is the most important factor limiting growth as may be expected to be the caseat many13 hatcheries While the spring renovation was not13 a complete success13 the dramaticreduction of fish populations in that habitat was enough to dramatically13 reduce13 the13 occurrenceof Ich at the hatchery13 Such open spring13 systems feeding a hatchery are a misfortune that canbe expected to transmit disease so we suggest that renovating the spring again to combat13 IchImproved techniques to divert water from13 the springs and more throuough treatment ofstream-shy‐side vegetation may improve the success of chemical treatment Successful renovationwould likely both improve growth rates and reduce chemical costs associated with treating Ichoutbreaks Even13 if complete renovation13 is impossible or impractical an13 effort to reduceinvasive fish density in the springs13 which act a vector for the parasite(and thereby reduce thelikelihood of13 Ich being transmitted into ponds) may still13 show dramatic improvements

36

13

Introduction

Conservation efforts13 for razorback sucker13 (Xyrauchen texanus)13 currently13 depend on

captive rearing and stocking programs Low survival of stocked razorback suckers (Brooks

1986 Marsh13 and13 Brooks13 1989 Marsh13 and13 Pacey13 2005) has13 caused13 target sizes for stocked13

fish to steadily increase in efforts to reduce predation mortality13 (Marsh13 et al13 2005

Schooley and Marsh 2007) Rearing fish to larger sizes at hatcheries comes with increased

costs and creates the need to evaluate husbandry and rearing practices that may affect fish

growth13 We evaluated growth13 rates13 of individual razorback suckers13 in ponds13 at Bubbling

Ponds Fish Hatchery13 using Passive Integrated13 Transponder (PIT) tags13 to13 obtain13 precise

growth information for individual fish so that valid comparisons of growth rates as related

to rearing practices can be made

Due to the critical nature of the razorback sucker stocking program we did not

design experimental studies that would require major rearrangement and potentially

reduce production of hatchery operations Instead our studies used normal variation in

production techniques and practices to isolate factors that may modify growth rates

Though this methodology dramatically limits replication and may limit our ability to

directly13 attribute13 differences in growth13 rates13 to13 the13 variables13 we13 investigate13 we13 were13 able13

to accomplish research goals without altering hatchery operations or impacting

production

From13 2009 through 2011 we conducted a series of observational13 growth13 studies to

determine growth rates of individual razorbacks at Bubbling Ponds The first set of

experiments included13 identifying13 growth13 rates13 in lined13 and13 unlined13 ponds determining

growth13 rates13 of fish at different13 sizes13 in13 relation13 to sorting13 practices and monitoring

razorback growth rates after removing the source of the ectoparasite13 Ich (Ichthiopthirus

multifiliis) from13 the hatchery water source13

Razorback growth rate in lined ponds

Our first growth study documented individual growth rates at normal density in 11

million gallon lined ponds13 over two13 years13 This is the standard13 grow-shy‐out process for

razorbacks13 at Bubbling Ponds We monitored growth of fish for a variety13 of sizes and13 the13

37

13

amount of time in a pond during the growing season These13 data give a snapshot of growth13

rates13 at the13 facility13 and13 provide13 the basis for comparisons throughout our study

Growth rate13 in an unlined pond

In addition13 to 6 ponds lined with heavy plastic13 sheeting13 Bubbling Ponds Fish13

Hatchery maintains two narrow and deep (same dimensions as lined ponds13 Figure13 4)13 and13

three large13 shallow unlined ponds These earthen13 ponds typically have vegetation and

associated aquatic invertebrates that may better simulate natural environments by

providing cover and improved food diversity or quality Therefore these unlined ponds

may be expected to produce higher growth rates and potentially improved survival that is

more similar to growth rates observed in more natural grow-shy‐out facilities13 Historically13 the13

large13 shallow13 ponds have produced very large fish when13 utilized at low13 fish density13 The

narrow13 deep earthen13 ponds are13 used to grow13 fry13 at high density in their first13 year of life

The major downside to unlined ponds is the difficulty in harvesting fish where a lined

pond might take 8-shy‐1013 people13 a half13 day13 to13 harvest13 lined13 ponds13 require13 intensive13 weeding13

to allow seines to be pulled and therefore require many more personnel-shy‐hours13 In addition13

to harvest challenges the shallow earthen ponds tend to suffer from13 dissolved oxygen

crashes during the summer Unlined ponds also may maintain higher13 populations13 of non-shy‐

target species such as bluegill sunfish mosquito fish and bullfrog tadpoles We measured

growth rates of suckers in a large shallow earthen pond for comparison to growth in lined

ponds13

Figure13 4 Lined13 and13 earthen ponds13 of similar dimensions (approx 1000000 gallons first

and second panels) and a large13 shallow13 earthen13 pond (third panel)

38

13

Effect of sorting on growth

Razorback13 suckers13 are13 currently13 sorted13 after their first13 year of growth13 They are13

typically removed from13 one of the13 upper earthen13 ponds and13 split into13 two13 lined13 ponds for

subsequent grow-shy‐out13 The larger13 fish (gt approximately 140 mm) are placed into one pond

and the smaller individuals in another It is possible that the larger fish were more

aggressive or adept13 at taking food so this sorting process is intended to allow smaller fish

to improve their growth rate

Effect of Ich on razorback sucker growth rates

We13 evaluated13 growth13 rates13 of razorback sucker13 in the13 presence13 and absence of the

ectoparasite13 Ich (Ichthiopthirus multifiliis) Ich outbreaks can occur in wild populations13 but

hatcheries13 have13 proven excellent locations13 for Ich because13 of very high fish densities13 which13

facilitate13 the13 transfer13 of Ich13 between13 fish This common fish parasite causes direct mortality13

to razorback13 suckers as well13 as secondary bacterial13 infections13

The open spring and13 ditch13 which13 provides water to the Bubbling13 Ponds Hatchery

has long13 been infested with mosquitofish (Gambusia affinis) that harbor13 the13 Ich parasite13

and allow13 it13 to enter the hatchery with incoming13 water13 The solution13 to13 the13 Ich problem13

was to remove the mosquitofish host using13 Rotenone Razorback13 sucker growth13 rates were13

then tracked in13 the absence of this parasite for 4 months and compared with growth rates

after Ich returned to the pond and from13 previous years

Methods

Razorback growth rate in lined ponds

On May 14 2008 141 razorback suckers were tagged with 12 mm PIT tags (1342

kHz) and placed in Pond 3 (approximately 1100000 gallons13 Figure13 4)13 at Bubbling13 Ponds

Fish Hatchery Fifty-shy‐three of these tags were recovered two months later when a large

Ichthyophthirius multifilis (Ich) outbreak killed many fish in the pond On October 15 2008

an additional13 145 PIT tagged13 fish were13 also placed into Pond13 3 On13 May13 14 2009 Pond13 3

was harvested and a total13 of 141 PIT tagged fish were recovered13 Of the tagged fish13 26 fish

had13 been13 in the13 pond since May13 of 2008 (378 days13 o growth) and 115 had been13 in13 the

39

13 40

pond since October13 15 2008 (211 days13 of growth) Numbers of fish in Pond 3 after the Ich

outbreak and for the majority of the period of growth were between 3 000 and 4000 fish

A Hobotempreg temperature13 logger13 was13 also13 installed13 in Pond 3 one meter below the water

surface13 near13 the13 outflow and13 recorded water temperature every 3 hours to allow analysis

of the effects of water temperature on growth rate (Figure13 5) This Hobotemp data is

representative of other pond temperatures throughout this study

In a second experiment 210 adult13 razorback suckers13 were13 PIT tagged13 on13 May 14

2009 and13 placed13 into13 Pond13 3 upper to13 evaluate13 growth13 rates13 of larger13 razorback suckers13 at

Bubbling13 Ponds Hatchery13 under current13 rearing13 conditions13 Size of these fish at tagging13

was (mean = 285 mm range = 205 ndash 396 mm) These fish remained in the pond for 257

days and were harvested on Jan 25 2010 to provide information on growth rates of larger

razorback suckers13 under13 current rearing conditions

Figure 513 Temperatures (degC) inrearing pond at BubblingPonds Hatchery from July toSept 2009 (top graph)13 andfrom Nov to Dec 2009 (Lowergraph) Temperaturesrecorded with a Hobotempregremote data logger13 every 3hours

13

Growth rate13 in an unlined pond

To document razorback sucker growth in earthen ponds we introduced13 225 tagged13

razorback suckers13 into13 Pond13 1 lower13 (Figure 4) in February 3 2010 Additional tagged fish

from13 other studies were added to the pond throughout the growing season and the density

of 1 lower reached a maximum13 of nearly 7000 fish in early summer 2010 Density was

reduced to approximately 6000 fish by capturing fish with hoop nets on June 3 2010 54 of

these fish were tagged fish and returned to 1 lower after being weighed and measured The

pond was harvested on January13 2713 2011 and a total13 of 254 tagged fish out13 of 4296 fish

total were removed from13 the pond The pond was harvested on January 27 2011 (358 days13

of growth) and the tagged fish were weighed and measured Total number of razorbacks in

the pond at harvest13 was 4296

Effect of sorting practices on growth rates

On March 1113 200913 Pond13 5 upper was13 harvested13 and13 split into13 two13 separate13 groups

Two hundred of the smaller fish (average size = 122 mm TL) were PIT tagged and placed

into13 Pond13 7 upper and13 200 of the13 larger13 fish (average = 160 mm TL) were PIT tagged and

placed int Pond13 8 upper Density13 in Pond13 7 was13 4500 fish and13 in Pond13 8 there13 were13 6500

fish These ponds were then harvested after 1 year and growth rates were compared to

give information on the effects of current sorting practices Hobotempreg temperature

loggers were installed in13 Ponds 7 and13 8 during13 the13 grow-shy‐out period with13 water13

temperature recorded every 2 hours13 (Figure13 6)

Effect of Ich on razorback sucker growth rates

Bubbling Ponds spring was treated with Rotenone (CFT Legumine 5) at a

concentration of 2 ppm13 to remove all mosquitofish from13 the spring The treatment

consisted of two treatments 6 hours in duration on two consecutive days (April 12 -shy‐ 13)

using13 drip13 stations13 and13 backpack sprayers13 followed13 by13 an13 additional 6 hours13 of

detoxification using sodium13 permanganate Although 12 mosquitofish were captured in the

spring pond the week following the treatments subsequent minnow trapping (20 traps

checked13 daily13 for 3 weeks) did not capture any additional fish until August 11 2010 when

41

13

juvenile mosquitofish were again detected in the spring pond Minnow traps have

subsequently been set daily with several hundred individuals removed To evaluate if Ich

was also again present in the spring we captured 15 mosquitofish from13 the spring pond on

three separate days and placed them13 in an aquaria at 25 degC with 5 longfin dace known to be

free of Ich These fish were monitored for 2 weeks with no signs of Ich developing This

indicates that even though mosquitofish have returned to the spring pond the parasite is no

longer present13 although how13 long13 this condition13 will13 persist13 is unknown13

On May 1113 201013 200 juvenile razorback13 suckers were harvested out13 of Pond 5

upper (2009 year Class from13 Dexter National Fish Hatchery) and were PIT tagged and

placed into Pond 8 to evaluate if growth rates at bubbling ponds hatchery have improved

following the renovation of the spring and the removal of the Ich parasite Unfortunately13

on Sept13 8 2010 Ich was13 again13 detected13 in Pond 8 and the pond was immediately seined

and 74 tagged fish were measured to obtain growth information for the 4-shy‐month period

during13 which13 the13 pond13 was13 Ich-shy‐free13

Figure13 6 Temperatures (degC) in rearingponds 7 and 8 at Bubbling Ponds Hatchery13 from March 2009 ndash March 201013 pond 7(top13 graph)13 and13 pond 8 (Lower13 graph)13 Temperatures recorded with a Hobotempregremote data logger every 3 hours

42

13

Results

Growth in Lined Ponds

Razorback suckers13 that had been13 in13 Pond 8 upper for the13 entire13 year13 grew an13

average of 0263 mmday (789 mmmonth) and razorback suckers that had been in the

pond for 7 months (Oct -shy‐ May) grew13 on13 average of 028 mmday (843 mmmonth) (Figure13

7) These growth13 rates13 did not significantly13 differ Fish density13 in Pond 3 during13 the13

majority of the growth period was13 00032 ndash 00036 fishgallon13 Additionally no13 significant

differences in growth rate were observed between fish smaller than 210 mm TL and fish

larger than 210 mm TL when all recaptured fish were combined

We also measured the growth rate of very large fish in a lined pond On Jan13 2513 201013

156 adult fish with PIT tags were recovered from13 Pond 3 upper13 These fish were13 in the13

pond for 257 days and experienced an average13 growth13 rate13 of 024mmday or 73

mmmonth (Figure13 7)13 This growth13 rate13 is slightly13 lower13 than13 the13 average13 growth13 rate13

observed13 at Bubbling13 Ponds Hatchery in other studies (0275 mmday 825 mmmonth)

but may not be biologically meaningful We would expect larger13 fish to13 have13 reduced

growth rates according to a typical Von Bertalanfy growth model (Bertalanffy 1957) but it

appears that13 over the size range we evaluated (300 -shy‐ 450 mm TL) growth rates have not

slowed significantly compared to that of smaller13 fish grown at Bubbling Ponds13 Hatchery

Growth13 of razorback suckers13 is known13 to13 slow as13 fish reach13 larger13 sizes but it appears13 this13

reduced growth rate may not really start to be biologically meaningful at Bubbling Ponds

Hatchery13 until razorback suckers13 exceed 450 mm TL

Growth in unlined ponds

Growth13 rates13 for the13 fish recaptured13 during13 the Pond 1 lower13 thinning13 (120 days13 in

the pond) was 024 plusmn 003 mmday (729 plusmn 090 mmmonth) (Figure13 8)13 Fish13 that were13 in

the pond for nearly the entire year grew13 an13 average13 of 024 plusmn 001 mmday (726 plusmn 027

mmmonth) These growth rates are surprisingly the lowest measured growth rates for

any part of our study and differ significantly from13 every other measured growth rate

except very large13 fish (Figure13 9)13 Separating13 out13 large fish that13 were in13 the pond for the

entire year makes no difference fish that were added to the pond at TL lt300 mm grew

43

13

Gro

wth

Rat

e (m

md

ay)

020

026

032

0244 plusmn 001 mmday (733 plusmn 028 mmmonth) and and those with TL gt= 300 mm at the

start of the experiment grew 022 plusmn 003 mmday (651 plusmn 101 mmmonth)

Razorback Growth Rates in Lined Ponds

Figure 7 Growth ofrazorback suckers in(mmday plusmn standard error)in Pond 8 upper in 2008-shy‐2009 An ANOVA did notdetect any significantdifferences

7 Months Full Year 300+ mm fish

Effects of sorting on growth

One hundred and seventy five tagged razorback suckers were recovered from13 Pond

8 upper13 on March13 24 2010 (378 days13 of growth)13 These were13 the13 larger sorted13 fish (gt140

mm TL) that came out of Pond13 5 on March13 11 2009 One13 hundred and13 twenty13 two13 tagged13

razorback suckers were also recovered from13 Pond13 7 upper on March13 31 2010 (385 days13 of

growth)13 These were13 the13 smaller sorted13 fish (lt140 mm TL) that came out of Pond13 5 on

March 1113 200913 No significant differences in growth rate (mmday) were observed among

larger fish in Pond 8 and smaller fish in Pond 7 (pgt005 ANOVA) (Figure 10)13 indicating

that13 sorting may have helped to offset the original slower growth trajectory of the smaller

fish Temperatures of Ponds 7 and 8 upper remained similar throughout the year13 (Figure

5)

44

13

13

13

Gro

wth

Rat

e (m

md

ay)

Gro

wth

Rat

e (m

md

ay)

020

026

032

020

026

032

Razorback Growth in an Unlined Pond

Figure 8 Growth of razorbacksuckers (mmday plusmn standard error) in Pond 1 lower (an unlined pond)in 2010-shy‐2011 An ANOVA did notdetect any significant differences

6 Months 12 Months lt 300 mm Fish 300+ mm Fish Growth Growth

Lined vs Earthen Ponds 1 year of growth

Figure 9 Growth of razorbacksuckers (mmday plusmn standard error) in lined and unlined ponds A t-shy‐test13 did not detect a significantdifference

Lined Pond Unlined Pond 1 Yr Growth 1 Yr Growth

45

13

Effect of Sorting G

row

th R

ate

(mm

day

) G

row

th R

ate

(mm

day

)

032

020

026

032

020

026

Smaller Fish Larger Fish

Effect of Ich

Figure 10 Average growthof razorback suckers(mmday plusmn standard error)that were size-shy‐sorted intosmall fish (pond 7) and largefish (pond 8) populations At-shy‐test did not detect asignificant difference

Figure 11 Average growth ofrazorback suckers (mmday plusmnstandard error) after Ich wasremovd from the hatcheryrsquos springand after Ich was again detected inthe pond The growth rate withoutIch is significantly higher than boththe rate after Ich and the ourstudyrsquos average annual growth ratein lined ponds (ANOVA p =00003)

Growth without Ich Growth With Ich Average Annual 4 months 4 months Growth Rate

46

13

Effect of Ich on razorback sucker growth rates

Seventy-shy‐four13 tagged13 razorback suckers13 were13 recovered from13 Pond 8 on September

15 2010 These fish had13 been13 in the pond for 4 months and experienced a growth rate of

032 mmday or 97 mmmonth (Figure13 11)13 This growth13 rate13 is significantly higher (p =

005 two sample t-shy‐test) than the mean growth rate for the same group13 of tagged fish after

Ich detection (022 mmday or 65 mmmonth) and significantly higher than any other

individual growth13 rates13 observed13 to13 date13 at Bubbling13 Ponds Hatchery13 (Figure13 11)13 If this13

growth13 rate13 were13 extended throughout13 the entire13 year13 fish on average from13 Ich-shy‐free13 ponds13

would be 16 mm longer than fish from13 ponds infested with Ich Studies conducted at

Bubbling Ponds hatchery in 2008 (Ward 2008) did not reveal any effects of the treatment

chemicals on razorback sucker growth rates so it13 is likely that13 the parasite outbreaks

themselves are causing reducing growth rates rather than the chemicals used to treat the

parasites13

Conclusions

Our results suggest that under typical hatchery operations (maximizing number of

fish produced)13 the growth13 rate13 of razorback13 suckers13 is relatively13 consistent at Bubbling13

Ponds hatchery13 at 02-shy‐03 mmday (6-shy‐9 mmmonth)13 but is lower than growth13 rates13 at

other13 facilities (02 ndash 18 mmday Ward et al 2007)13 This growth13 rate13 has13 been13 constant in

both lined and unlined ponds and at all fish densities we were able to measure To achieve13

growth13 rates13 substantially higher than this will likely require13 significant changes in rearing

practices that may not be practical in order to reach numerical production13 goals

Temperature is a key variable in fish growth but seasonal growth patterns

described13 above13 (Figure13 5) demonstrate that water temperatures are high enough in

winter to maintain razorback growth Differences in water temperature by season

currently13 do not fluctuate more than 10degC at Bubbling Ponds because of the continuous

supply of water flowing through each pond (approx 225 gallonsmin) These high water

flows appear to keep pond temperatures within the thermal preference13 for razorback

suckers13 (1213 -shy‐ 28 degC Bulkley and Pimentel 1983) throughout the entire year with

temperatures rarely dropping13 below 16deg13 C (Figures 513 6)13

47

13

Fish density is another key variable in fish growth and though the number of fish in

a pond during our study ranged from13 3000 to 700013 fish we13 did not find any13 correlation13

between13 density and growth rate13 This might yield two conclusions First13 razorback

growth13 may be changed equally13 by13 densities13 at the13 hatchery13 (ie13 a density13 of 3000 fish in a

pond is as stressful13 for razorbacks as a density13 of 7000 fish) An alternative is that other

factors13 such as disease outbreaks have13 stronger13 control over fish growth13 than13 density13

Fish density13 would13 have13 to13 be13 experimentally manipulated to test13 this13 and hatchery

operations (producing the maximum13 number of fish) prevented our manipulating density13

in ponds for this13 work The trouble with manipulating density demonstrates the difficulties

associated with changing13 hatchery13 practices experimenting with density would have

prevented BPH from13 meeting13 production13 goals Given that the stocking of smaller

razorbacks has met with very little success perhaps BPH goals could be changed from13

producing 12000 fish at 300+ mm per year to a smaller number of very large fish each

year Growing13 fewer13 larger13 fish could potentially be accomplished in the same time frame

as more smaller fish but a better understanding of how density alters growth rate would

be required to be confident13 of this

The very slow growth13 in the13 earthen13 unlined13 Pond 1 lower13 was very surprising We13

had13 anticipated13 that the13 diversified diet13 cover and13 other13 habitat features13 provided by13

unlined ponds would yield dramatically increased growth rates However these traits were

not enough to offset high fish densities and in fact the unlined pond in our study13 suffered

mortality to bring densities down to that observed normally in lined ponds

Our data13 suggest13 that razorbacks13 sucker13 growth13 rates13 are13 higher in lined13 ponds13

However we13 think the reasons13 for the13 very slow growth we observed13 in the13 unlined13 pond13

in our study13 is instead13 linked13 to13 the13 usage13 of Pond 1 lower13 during13 the13 study13 rather13 than13

intrinsic13 slow growth13 in earthen13 ponds First the pond was at extremely high density for at

least part of the study The volume of Pond 1 lower has not been estimated but hatchery

managers suggest 1500-shy‐2000 fish is an appropriate number of individuals so this pond

was at a very high density for much of the experiment Second dissolved oxygen is often

very low in the13 large13 earthen13 ponds during the heat of summer much lower than that of

lined ponds This will both limit the number of fish that can survive in the pond and almost

certainly13 increases stress13 of these13 fish potentially13 reducing growth13 The DO crashes also13

48

13

limit the amount of feed hatchery managers can give fish in these ponds sometimes for

days or weeks at a time which further reduces growth during warm13 weather

Our data13 suggests that13 growth rates at the Bubbling13 Ponds Fish Hatchery are likely

as high as possible given13 the pond densities required to meet production goals and the Ich-shy‐

infested water that feeds the facility Sorting practices are successful in helping as many

fish as possible reach stocking length as fast as possible Unlined ponds may be able to

grow13 large13 fish at low13 densities13 but whatever factors allow13 for that13 growth are not13 able to

overcome high fish density The removal of invasive13 fis that act as13 a host for the13 parasite13

Ich fish from13 the Bubbling13 Ponds spring13 allowed the highest13 growth rate at 032 mmday13

(96 mmmonth) but that growth rate decreased again as Ich re-shy‐infested13 the13 hatchery13

Consistently13 achieving13 growth13 rates13 as high or substantially13 higher than13 this13 will likely13

require13 significant changes in rearing practices that may not be practical in order to13 reach13

numerical production13 goals

Two major changes that might result in higher growth rates are substantially

reducing fish density and modifying the way spring water is delivered to the facility (via

either repeated chemical treatments or enclosed concrete water diversions) to eliminate

Ich from13 the hatchery source water Other potential changes not address by our work

include13 flow-shy‐training razorbacks much previous literature including MSCP-shy‐funded13 work

on razorback suckers13 suggests13 that fish growing13 in flowing water will grow13 faster than fish

in still water (Jorgensen and Jobling 1994) Furthermore there are a wide variety of

potential benefits associated with growing13 fish13 in flowing13 water in addition13 to increased

growth13 rates13 (Davidson13 199713 Castro13 et al13 2011) Another option13 for increasing13 growth13

rates13 include13 changing to13 intensive13 culture13 in large circular13 tanks

Finally given that the stocking of smaller razorbacks has met with very little

success13 perhaps13 BPH13 goals13 could13 be13 changed from13 producing 12000 fish at 300+ mm per

year to a smaller number of very large fish each year Growing fewer larger fish could

potentially be accomplished in the same time frame as more smaller fish but a better

understanding13 of how density13 alters growth13 rate13 would13 be13 required to13 be13 confident of this

49

13

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower13 Colorado13 River Multi-shy‐Species13

Conservation Program13 (LCRMSCP) under Work Task C10 We13 thank Ty Wolters13 Tom13

Burke13 and Eric13 Volkman for their support of this research and Frank Agygos and Dave

Billingsly13 of the Bubbling13 Ponds Fish Hatchery13 for their willingness to participate in13 this

research13 and13 for their technical assistance We also thank the LCRMSCP fish group from13

Boulder City13 NV for their assistance with harvesting13 ponds and tagging13 fish13

50

13

Literature13 CitedAnders P J 1998 Conservation aquaculture and endangered species can objective science13

prevail13 over risk13 anxiety Fisheries 23(11) 28-shy‐31

Anderson R O and R M Nuemann 1996 Length weight and associated structural indicesPages 447 ndash 482 in B R Murphy13 and D13 W Willis13 editors13 Fisheries techniques13 2ndedtion American Fisheries13 Society13 Bethesda13 Maryland

Bain M B J T Finn and H E Brooks 1988 Streamflow regulation and fish communitystructure13 Ecology13 69382-shy‐392

Bays J H Zarbock R Whitman and T Murphy 2005 Conceptual design and managementof native13 fish refugia on the13 lower13 Colorado13 River In13 CL Spring13 and13 S Leoneditors Proceedings of two symposia Restoring native fish to the lower ColoradoRiver13 interactions13 of native and non-shy‐native13 fishes 13ndash1413 July13 1999 Las13 Vegas13 Nevada13 Restoring13 natural function within a modified riverine environment thelower Colorado River13 8ndash913 July13 1998 U S Fish and13 Wildlife13 Service Southwestern13 Region Albuquerque New Mexico Pages 167-shy‐177

Bertalanffy L Von 1957 Quantitative laws in metabolism13 and growth13 Q Rev Biology 32217 ndash 231

Bingham T B Scheer and C McAda 2003 Propagation facilities in Grand Valley (24 RoadHatchery Horsethief13 Ponds and13 grow-shy‐out ponds) for captive13 rearing13 ofendangered13 fishes for the13 upper13 Colorado13 River basin13 Colorado River RecoveryProgram FY2003 annual project report13 US Fish and13 Wildlife13 Service GrandJunction13 4pp

Birchell G J and K Christopherson 2004 Survival growth and recruitment of larval andjuvenile razorback13 sucker (Xyrauchen texanus) introduced13 into13 floodplain13 depressions13 of the13 Green River Utah13 Final report13 Upper13 Colorado13 RiverEndangered Fish Recovery Program13 Project No C-shy‐6RZ Publication Number 04-shy‐1513 Utah13 Division of Wildlife13 Resources Salt Lake13 City13 Utah13 67 pages

Brannon E L 1993 The perpetual oversight of hatchery programs Fishery Research 1819-shy‐27

Brett J R 1979 Environmental Factors and growth pages 599-shy‐67513 InW S Hoar13 D13 J13 Randall and J R Brett (eds) Fish Physiology Volume 8 Bioenergetics and GrowthAcademic Press New York

Brooks J E 1986 Annual reintroduction and monitoring report for razorback suckerXyrauchen texanus in the Gila River Basin Arizona 1985 US Fish and WildlifeService13 Offices of Endangered13 Species and Fishery13 Resources Albuquerque 23 pp

51

13

Brunson13 R E and K D13 Christopherson13 200513 Larval13 razorback13 sucker and bonytailsurvival and13 growth13 in the13 presence13 of nonnative13 fish in the13 Baeser13 floodplainwetland of the middle Green River Final report prepared for Upper13 Colorado RiverBasin Endangered Fish Recovery Program Project No C-shy‐6-shy‐rz-shy‐bt Publication13 No 05-shy‐26 Utah13 Division of Wildlife13 Resources13 Vernal13 32 pp

Bulkley R V and R Pimentel 1983 Temperature preference and avoidance by adultrazorback suckers Transactions of the American Fisheries Society 112601-shy‐607

Burke13 T13 199513 Rearing13 wild razorback13 sucker larvae in13 lake-shy‐side13 backwaters13 LakeMohave ArizonaNevada Proceedings of the Desert Fishes Council 2635

Busacker G P I R Adelman and E M Goolish13 199013 Growth13 Pages 363 ndash 387 in C BSchreck and p B Moyle editors Methods for fish biology American FisheriesSociety Bethesda Maryland

Castro V B Grisdale-shy‐Helland S J Helland T Kristensen S M Jorgensen J Helgrud13 GClaireaux A P Farrell A Krasnov and H Takle 2011 Aerobic training stimulatesgrowth and promotes disease resistance in Atlantic salmon (Salmo salar)Comparative Biochemistry and Physiology -shy‐ Part A Molecular amp IntegrativePhysiology13 160(2) 278-shy‐290

Czapla T E 2002 Facilities plan for the production of endangered fishes to meet statestocking13 plans13 as13 part of the13 Upper13 Colorado13 River Endangered13 Fish RecoveryProgram Upper Colorado River Basin Recovery Implementation Program US Fishand Wildlife Service13 Denver13 9 pp

Davidson W 1997 The effects13 of exercise13 training on teleost fish a review of recentliterature Comput Biochem Physiol 117A67ndash75

Figiel Jr C R 2005 Annual report fiscal year 2004 Willow Beach National13 Fish HatcheryUS Fish and Wildlife13 Service Willow Beach 17 pp

Figiel Jr C R M E Ulibarri G Carmichael J Seals and J N Hanson 2005 Intensive13 fish13 culture of warmwater native fishes at a coldwater fish hatchery Pages 164-shy‐16613 inProceedings of two symposia restoring native fish to the lower Colorado13 River13 interaction13 of native13 and13 non-shy‐native13 fishes July13 13-shy‐1413 1999 Las Vegas Nevada USFish and Wildlife Service Southwest Region Albuquerque New Mexico

Gerking13 S D 1978 Ecology of freshwater fish13 production13 Halstead Press13 New13 York

Gustafson W and Q Bradwisch 2000 Wahweap operation and maintenance -shy‐-shy‐ UtahColorado River Recovery Program FY 2000 annual project report Project No 29cUtah13 Division of Wildlife13 Resources Page AZ 3pp

52

13

Hamman R L 1985 Induced spawning of hatchery-shy‐reared13 razorback sucker ProgressivFish Culturist 47(3) 187-shy‐189

Hanson J N 1996 Annual report fiscal year 1996 Willow Beach National Fish HatcheryUS Fish and Wildlife Service13 Willow Beach 9pp

Irving D S Seversen and M Montagne 2004 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2004 annual project13 report Report No 29b US Fish and13 Wildlife13 Service Vernal 3pp

Jorgensen E H and13 M Jobling 1994 Feeding and13 growth13 of exercised13 and13 unexercised13 juvenile Atlantic salmon in freshwater and performance after transfer to seawaterAquaculture International 2 154-shy‐164

Kaeding L R and D B Osmundson 198913 Colorado13 Squawfish13 and13 razorback sucker grow-shy‐out pond studies as part of conservation measures for the green mountain andRuedi reservoir water sales Final report for agreement number 6-shy‐AA-shy‐60-shy‐00150

Koebele13 B P13 198513 Growth and the size hierarchy effect an experimental assessment ofthree proposed mechanisms activity differences disproportional food acquisition13 pysiological stress Environmental Biology of Fishes 12 181-shy‐188

Kretschmann A E and L L Leslie 2006 Razorback sucker (Xyrauchen texanus) status13 reproduction and recruitment in Senator Wash Reservoir CA Final Report13 to USBurea of Reclamation Cooperative Agreement No 00-shy‐FG-shy‐34-shy‐ 0009 p 32 ArizonaGame and Fish Department Phoenix

Marsh13 P13 C13 1987a13 Digestive tract13 contents13 of adult razorback suckers13 in Lake13 MohaveArizona-shy‐Nevada Transactions of the American Fisheries Society 116117-shy‐119

Marsh P C 1987b Native fishes at Buenos Aires National Wildlife Refuge and ArizonaState University Research Park Arizona opportunities for management researchand public13 education13 on13 endangered species13 Proceedings of the Desert13 FishesCouncil 1967-shy‐78

Marsh P C 1994 Rearing native Colorado River fishes in golf course ponds Arizona StateUniversity Tempe 22 + pages

Marsh13 P13 C13 200013 Fish population13 status and evaluation13 in13 the Cibola13 High Levee PondFinal report agreement number 99-shy‐FG-shy‐30-shy‐00051 US Bureau of ReclamationBoulder City13 Nevada13 20 pages

Marsh P C and C A Pacey 1998 Growth of wild adult razorback suckers13 in Lake13 Mohave13 Arizona-shy‐Nevada13 Final report13 US Bureau of Reclamation Boulder City Nevada 25pages + appendices

53

13

Marsh P C B R Kesner and C A Pacey 2005 Repatriation as s management strategy13 to13 conserve a critically13 imperiled fish species North American Journal of FisheriesManagement 25 547-shy‐556

Marsh P C and C A Pacey 2005 Immiscibility of native and non-shy‐native13 fishes Pages 59-shy‐63 inMJ13 Brouder13 CL13 Springer13 and CS13 Leon13 editors13 Proceedings of two13 symposia Restoring native fish to the lower Colorado River interactions of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 NV and13 Restoring natural13 function within a modified riverine environment the lower Colorado River13 July13 8-shy‐913 1998 Las Vegas NV US Fish and13 Wildlife13 Service Southwest Region AlbuquerqueNew Mexico

Marsh13 P13 C13 and J13 E Brooks13 198913 Predation13 by ictalurid catfishes as a deterrent13 toreestablishment of hatchery-shy‐reared13 razorback sucker The Southwestern Naturalist34188-shy‐195

Matthews R A 2005 Ichthyopthirus multifiliis Fouquet and Ichthyopthirosis infreshwater13 teleosts13 Pages13 159-shy‐218 in Advances in Parasitology volume 59 J RBaker R Muller D Rollinson (eds) Academic Press

McCarthy13 M S and W L Minckley 1987 Age estimation for razorback sucker (PiscesCatostomidae) from13 Lake Mohave Arizona and Nevada Journal of the Arizona-shy‐Nevada Academy of Science 2187-shy‐97

Minckley13 W L13 198313 Status of the razorback13 sucker13 Xyrauchen texanus (Abbot)13 in13 thelower Colorado River basin13 The Southwestern13 Naturalist13 28(2) 165-shy‐187

Minckley13 W L13 199113 Native fished of the Grand Canyon13 region an obituary13 Pages 124-shy‐177 in Colorado River ecology and dam13 management National Academy PressWashington13 DC

Minckley13 C13 O and M LaBarbara13 199913 Report13 on13 native fish grow-shy‐out facilities13 at Cibolaand Imperial National Wildlife Refuges 1993-shy‐199513 US Fish and13 Wildlife Service13 Parker Fishery Resources Office Parker Arizona

Modde13 T13 199613 Juvenile razorback sucker (Xyrauchen texanus) in a managed wetlandadjacent13 to the Green13 River13 Great13 Basin13 Naturalist13 56375-shy‐376

Modde T KP Burnham and E J Wick 1996 Population status of the razorback sucker13 inthe middle Green River (USA) Conservation13 biology 10 110-shy‐119

Modde13 T13 and G13 B Haines13 200513 Survival13 and growth of stocked razorback13 sucker andbonytail in multiple floodplain wetlands of the middle Green River under resetconditions13 Final report prepared for Upper Colorado13 River13 Basin RecoveryImplimentation Program US Fish and Wildlife Service Vernal 66 pp

54

13

Modde T Z H Bowen and D C Kitcheyan 2005 Spatial and temporal use of a spawning13 site in the middle Green River by wild hatchery-shy‐reared13 razorback suckers13 Transactions of the American Fisheries Society 134937-shy‐944

Mueller13 G13 199213 The native fish work13 group13 -shy‐ a multiagency endeavor to improve thestatus of the razorback sucker in Lake Mohave AZ-shy‐NV13 Proceedings of the DesertFishes Council 2369

Mueller G 1995 A program13 for maintaining the razorback sucker in Lake MohaveAmerican Fisheries Society Symposium 15127-shy‐135

Mueller13 G13 200613 Ecology of the bonytail13 and razorback13 sucker and the role of offchannelhabitats13 in their13 recovery Scientific13 investigations13 report 2006-shy‐5065 US GeologicalSurvey13 Denver

Mueller G and E Wick 1998 Testing of golf course ponds at Page Arizona for suitability13 as grow-shy‐out facility for razorback sucker using surplus fish from13 Ouray NationalFish Hatchery National Park Service US Fish and13 Wildlife13 Service and UtahDivision of Wildlife13 Resources 28 pages

Mueller13 G13 and T13 Burke13 200513 Survival13 of young13 razorback13 sucker (Xyrauchen texanus) inrelation to13 stocking rates13 (fishha)13 and13 in the presence13 or absence13 of predatorcommunities in Lake Mohave Arizona-shy‐Nevada13 Pages13 155-shy‐16313 in Proceedings of two13 symposia restoring native fish to the lower Colorado River interaction13 of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 Nevada US Fish and Wildlife13 Service Southwest Region Albuquerque New Mexico

Mueller13 G13 J13 Carpenter13 and P13 C13 Marsh13 200413 Cibola13 High Levee Pond annual report 2004US Geological Survey Fort Collins13 Science Center13 Colorado13 and Arizona StateUniversity Tempe 23 pages

Nesler T P K Christopherson J M Hudson C W McAda F Pfeifer and T E Czapla 2003An integrated stocking plan for razorback sucker bonytail and Colorado13 pikeminnow for the Upper Colorado River Endangered Fish Recovery ProgramAddendum13 to State Stocking Plans Upper Colorado River Basin Recovery13 Implementation Program 12 pp

Papoulias13 D and W13 L Minckley13 1992 Effects13 of foo availability13 on survival and growth13 of larval razorback suckers13 in ponds Transactions of the American Fisheries Society121340-shy‐355

Paukert13 C P D L Ward13 P J Sponholtz13 and K13 D Hilwig13 Effects13 of repeated hoopnetting13 on bonytail chub13 Journal of Freshwater13 Ecology13 20(4) 649-shy‐653

Pfeifer F M13 C Baker13 and M13 Montagne13 199913 Propagation13 facilities13 in the13 Grand Valley13 (24 Road13 Hatchery13 Horsethief13 Ponds and13 grow-shy‐out ponds) for captive rearing of

55

13

endangered13 fishes for the13 Upper Colorado13 River Basin13 Colorado13 River Recovery13 Program FY 99 annual project report Project No 29a13 US Fish and Wildlife Service13 Grand13 Junction13 5pp

Pfeifer F S Seversen and M Montagne 2003 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2003 annual reportProject No 29b13 US Fish and Wildlife13 Service Vernal13 4pp

Rabago-shy‐Castro J L Sanchez13 J G Perez-shy‐Castaneda R and13 Gonzalez-shy‐Gonzlez A 2006Effects of the prophylactic use of Romet-shy‐3013 and13 copper13 sulfate13 on growth13 condition13 and feeding13 indicies in13 channel13 catfish (Ictalurus punctatus) Aquaculture 253 343-shy‐349

Reinitz GL L E Orme and F N Hitzel 1979 Variations of body compositio and growth13 among strains of rainbow trout Transactions of the American Fisheries Society 108204-shy‐207

Ruppert13 J13 B P B Holden13 and P D Abate 1999 Age estimation and growth of razorbacksucker13 Xyrauchen texanus in Lake13 Mead Nevada Proceedings13 of the Desert FishesCouncil 3040

Schnoor K D and J Logan 2002 Operation and maintenance of JW Mumma nativeaquatic13 species restoration facility Colorado Colorado River Recovery Program FY2002 annual project report13 Project No 29d Colorado13 Division of Wildlife Alamosa3pp

Salisbury13 L13 1998 Factors13 affecting razorback13 sucker growth13 in Lake13 Mohave backwaters13 MS Thesis13 Unviersity13 of Nevada13 Las13 Vegas

Schooley J13 D13 and P C13 Marsh13 2007 Stocking of endangerdd13 razorback13 suckers13 in thelower Colorado River Basin13 over three decades 1974-shy‐2004 North American Journalof Fisheries Management 27 43-shy‐51

Severson S H H M Tyus and G B Haines 1992 An evaluation of feeds for raisingrazorback sucker Xyrauchen texanus Journal of Applied Aquaculture 155-shy‐65

Toney D P 1974 Observations13 on the13 propagation13 and13 rearing13 of two13 endangered species13 in a hatchery environment Proceedings of the Annual Conference of the Western13 Association of State Game and Fish Commissions 54 252-shy‐259

Tyus H M13 1998 Razorback sucker13 (Xyrauchen texanus) recovery plan13 University13 ofColorado Center for Limnology Boulder13 76 pages

Tyus H M13 and13 S H Severson 1990 Growth13 and13 survival of larval razorback suckers fedfive formulated diets The Progressive Fish Culturist 52197-shy‐200

56

13

Ulibarri M E 2003 Annual report fiscal year 2001 Dexter National Fish Hatchery13 andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 26 pages

Ulibarri M E 2003 Annual report fiscal year 2002 Dexter National Fish Hatchery andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 59 pages

USBR 2006 Lower13 Colorado13 River Multi-shy‐Species Conservation Program final fishaugmentation plan Boulder City 19 pp

USFWS 2002 Razorback sucker (Xyraouchen texanus) recovery goals Amendment andsupplement to the Razorback Sucker Recovery Plan13 US Fish and Wildlife Service13 Region 6 Denver13 Colorado

USFWS 1999 Annual report 1999 Ouray National Fish Hatchery Vernal 25pp

USFWS 2004 Management plan for the big-shy‐river13 fishes of the13 lower13 Colorado13 river basinamendment and supplement to the bonytail humpback chub Coloradopikeminnow and razorback sucker recovery plans

USFWS13 2005 Station13 profile13 of the13 Dexter13 National Fish Hatchery13 and Technology CenterUS Fish and Wildlife13 Service Dexter

Valdez R A P G Mangan R Smith and B Nilson 1982 Upper Colorado River fisheriesinvestigations13 inW H Miller J J Valentine D L Archer H M Tyus R A Valdezand L13 Kaeding13 editors13 Colorado River Fishery13 Project13 Part 2 Field13 investigations13 US Bureau of Reclamation Salt Lake City Utah

WBNFH 2004 Culture methods of the endangered razorback sucker Xyrauchen texanusUS Fish and Wildlife13 Service Willow Beach National Fish Hatchery13 8 pp

Ward D 2008 Effects of disease treatments on growth of razorback sucker ReportSubmitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 Inpartial fulfillment of work task C10 agreement number 06FG30039

Ward13 D13 M Childs and W Persons 2007 Factors13 affecting13 growth13 of razorback sucker13 (Xyrauchen texanus) in captivity Literature review and knowledge assessmentReport Submitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 In partial fulfillment of work task C10 agreement number 06FG30039

57

Appendices

Appendix 1 Survey Questions Survey of Razorback Sucker Culture in the

Southwestern United States

The enclosed survey is being distributed by the Arizona Game and Fish Department to razorback sucker culture facilities throughout

the Southwestern United States The purpose of this survey is to consolidate information regarding culture of this species so that

appropriate facility improvements can be considered for Bubbling Ponds Hatchery in Arizona Specifically we wish to increase

growth rate and production efficiency at the hatchery Information gathered in this survey will be summarized in a final report to US

Bureau of Reclamation in Boulder City NV and disseminated to all facilities that participate in the survey A workshop to discuss

the findings of this study as well as to share general information concerning razorback sucker culture will be organized by the

Arizona Game and Fish Department at the conclusion of this study and all participants will be invited

Thank you for taking the time to fill out this survey Please contact Mike Childs if you have questions or would like to discuss the

survey

Mike Childs

mchildssedonanet

(928) 639-1346

(928) 634-1279

Facility_____________________________________ Date___________________

Contact Phone _____________________________

ContactPerson_______________________________

Contact Email _______________________________

1 Water quality ranges at this culture facility

Season

Spring (Mar-May) Summer (Jun-Aug) Fall (Sept-Nov) Winter (Dec-Feb)

Temperature (C)

PH

DO (mgL)

PO4 (mgL)

TDS (mgL)

Hardness (mgL)

CaCO3

Pathogens

37

13

Basin13 Ponds where broodstock13 are reared13 diseases such as Ich are problematic because

water is pumped directly from13 the Colorado River

Ouray13 National Fish Hatchery13

Ouray13 National13 Fish Hatchery maintains its own broodstock and13 spawns13 fish on-shy‐site13

Larvae are transferred from13 indoor hatching tanks to unfertilized 02 acre outdoor ponds

and stocked at densities 10000 ndash 20000 larvae13 per13 pond13 Even13 though13 outdoor13 ponds13 are13

covered with13 bird13 netting13 avian predators13 still get caught in the13 nets13 if they13 can see fish

Ponds are dyed blue13 as the13 fish grow to13 prevent avian predation13 While in the outdoor

ponds13 fish13 are13 fed a slow-shy‐sinking salmon diet made by Silvercupreg twice daily by hand

Amount of feed is based on periodic sample counts Fish are grown until late September at

which time temperatures require that all fish13 other13 than13 adult broodstock13 be13 brought

inside for the winter Ponds are drained completely and fish are sorted by hand Fish that

have reached the target size (300 mm TL) are stocked into the Green and Colorado Rivers

All remaining fish are moved indoors13 and13 held13 in three-shy‐foot (n= 30) or eight-shy‐foot (n=27)

diameter circular tanks On average it takes 12 ndash 18 months to grow fish to the 300 mm TL

at Ouray13 hatchery13

Razorback suckers are held during the winter in a recirculating system13 that

operates13 using13 two13 large13 fluidized-shy‐bed sand filters and a rotating-shy‐drum13 filter for solids

removal Fish are fed the Silvercupreg razorback diet using belt feeders There is currently

capacity13 to13 hold13 only13 20000 200-shy‐300 mm TL fish inside the facility and any extra fish13 are13

stocked13 into13 floodplain-shy‐wetlands or used for research purposes13 Ouray no longer leases

any private grow-shy‐out ponds Grow-shy‐out ponds were troublesome due to poor water quality

harvesting13 difficulties13 and13 non-shy‐native13 fish introductions13 The biggest difficulty13 for

production13 of razorback13 suckers at the Ouray13 National13 Fish13 Hatchery13 is space13 during13 the

winter to maintain large numbers of fish and high iron and manganese in the well water

that must be filtered out prior to use

16

13

Willow Beach National Fish Hatchery13

Willow13 Beach National13 Fish Hatchery receives wild-shy‐caught larvae from13 Lake

Mohave Larvae are treated for diseases with formalin and malachite green and placed in

45 ten-shy‐gallon13 flow-shy‐through aquaria13 Recirculated13 solar heated water13 22-shy‐25deg C is used to13

allow production of warm13 water fish at this traditionally cold water facility (Figiel 2003

Figiel et al 2005) Fish are fed brine shrimp nauplii to satiation every hour and after 14

days small amounts of specialized larval fish diet (Encapsulon13 Cyclopeeze13 spirulina13 and

artificial plankton) are introduced After 30-shy‐6013 days13 fish are13 transferred13 to13 six13 32-shy‐gallon13

fiberglass troughs at densities of 1000 to 1500 fish per tank and then a month later moved

outside13 to13 eight recirculating13 raceways that use a combination of well water and solar-shy‐

heated water to maintain temperatures of 22 ndash 25deg C during the summer months

When13 in13 the outside raceways13 fish are fed the razorback13 diet13 using13 belt13 feeders and

fed by13 hand13 at 10 -shy‐ 70 body13 weight per13 day Feed amount is adjusted based on sample

counts according to a feed conversion program13 developed for razorback suckers by Willow

Beach Hatchery personnel This program13 uses length and number-shy‐per-shy‐pound generated

from13 several years of razorback growth data (Figure13 1) Fish are13 sorted13 opportunistically13

and are not handled during the summer months when water temperatures are above 20degC

In 2004 the target size for stocking was 325 mm TL or greater (WBNFH 2004) with a

target13 of producing13 6000 fish per year Reaching this13 target size usually13 takes13 two13 growing13

seasons13 The biggest difficulty13 in rearing13 razorback suckers13 at Willow Beach13 National Fish

Hatchery13 is insufficient space13 to13 grow fish to13 increased13 target sizes (400-shy‐500 mm TL)

Uvalde13 National Fish Hatchery13

Uvalde13 National Fish Hatchery13 in Texas13 receives 35000 ndash 60000 razorback sucker13

fry annually in MarchApril from13 Dexter National Fish Hatchery The fry are acclimated in

bags submerged in the pond for a minimum13 of one hour and released into13 a 1 acre13 fertilized13

pond where they are reared for the remainder of the summer Fingerlings are fed a starter

razorback diet when they reach approximately 50 mm TL In AprilMay the previous year

class of razorbacks are captured from13 their over-shy‐wintering pond enumerated graded and

split into13 one-shy‐acre grow-shy‐out ponds Approximately 4000 ndash 5000 fish will be13 placed13 in each13

one acre pond for summer grow-shy‐out Fish are reared for approximately 150 days (May ndash

17

13

Oct) and fed the Bozeman razorback diet two times a day five days a week at 15 ndash 30

body weight per day based on average water temperature

Figure 1 Relationship between length and number of fish per pound

In general13 juvenile razorback13 suckers (received as fry13 during13 the previous spring)13

reach the target size of 300 mm TL in approximately 6 months In 20062007 Uvalde

produced 6000 razorback suckers 300 mm TL for introduction into the San Juan River

Starting13 in 2008 Uvalde NFH will be producing13 and distributing13 12000-shy‐ 300 mm TL

razorbacks for stocking into the San Juan River Predation from13 migrating cormorants has

occurred but timing of harvest and over wintering protection methods such as covering

ponds with netting or placing fish indoors helps to minimize losses during the cormorant

migration (November to March) Uvalde has experienced razorback mortalities because of

bacterial problems but these are usually resolved through the use of oxytetracyline

medicated feed

Overview13 of Differences in Culture Methods

Several differences were noted when conducting surveys at each of the five main

production facilities for razorback sucker (See Appendix 3) These differences include

different stocking13 and13 rearing13 densities13 (Table13 4-shy‐5) various feeding regimes and type of

18

13

lt=amp

feeds (Table 7) as well as differences in grading or sorting practices Some of these

differences are13 related13 to13 whether13 or not razorback suckers13 are13 being13 reared13 in extensive-shy‐

culture13 facilities13 (ponds) or intensive-shy‐culture13 settings13 (raceways13 o tanks)13 Some13 practices13

are unique to a single facility13 or a couple of facilities (Table 6)13 Managers at each facility13

were asked to identify the biggest13 difficulty or constraint13 that13 they experience when13

growing-shy‐out juvenile13 razorback suckers13 at their13 respective13 location13 Space constraints13

water quality and disease problems were the main factors limiting production of razorback

suckers13 at these13 facilities13 (Table13 8) Calculated or reported growth rates from13 the literature

vary widely (Table 9) and range from13 02 to 18 mmday These growth rates indicate that

juvenile razorback suckers have a very high growth potential under optimal rearing

conditions13

Table13 4 Stocking13 densities13 for larvae13 and13 fry in ponds

$amp( )(+amp-( 01-2(3(4amp56( 4amp56(+amp-( 01-2782-( $amp () + --amp +amp0amp)+amp 12-3amp ( )+amp0amp+amp --amp +amp0amp)+amp 42556789amp8 ( +amp0ampgt+amp 3amp +amp0amp+amp A-BC-Damp (E + 3amp )+ F-6ltamp ) G+ 3amp G+

Table13 5 Rearing13 densities13 at intensive13 culture13 facilities13

$amp( )amp+(($-( $0( 12(3$+( 40((amp05( 67((amp05( 8$9(407$( $amp amp())amp++-$amp 0 1 0amp2amp1amp 3amp2amp4 0544

6amp())amp++-$amp 610 021 4amp2amp47amp 3amp2amp77amp 058 9$amplt+)amp 4amp())amp++-$amp 00 1 7amp2amp77amp 851amp2amp0amp 05

6amp())amp++-$amp 610 77amp2amp1amp 0amp2amp1amp 053

19

13

Table13 6 Rearing13 practices13 that are13 unique to13 specific rearing13 facilities13 $$amp( )$+-(amp$-(0(1-amp2034( $amp()amp+( -0$(12(33+(amp(amp134$53+(amp$amp3+(6amp+(

723(843(1$8(422(6amp+(42amp(4(423(19$43( 343( lt34$53(6amp+(6(4($03(amp4+94amp(842($1$1(63$$34(amp+(63626243( =amp+(gtamp94ampA( B3(1(1$+53+C3+(amp+(1$43(1(3D0$(1(amp443(amp+(amp443( 734231(amp( B3(1(193(44(1(34amp(amp(+49E(6amp+( -E3(F3+( G3amp(1(12(amp(H3(13$(4ampE(C(IJK($$amp( A( L43(+A3(4(6303amp4(63+4ampM(66$3D3amp4$(34amp(amp(6amp+(C((4amp3( L$$8(392(

B0$+3(

N43D(13+(4($0$(12M(amp+(639$53+($0$(12(+34( G3amp(12(amp(399$4amp(4+(938A(842($(2343+(843( N443D643+(3amp(12(amp(amp34(63amp(amp(423(O$+(G03( )amp+(3(134$53+(6(4(39364(1(1A(4(44(423D(amp((D3(amp4$(+34(

Table13 7 Types of feed used at razorback sucker13 hatcheries13 $amp ()amp+-amp0- $$)1amp23 45-amp)-$5)1amp23 $amp()amp+( -amp$amp+(amp+( -amp012$3+(amp+4(amp5215$(0+( 65ampamp7(85209(+2($1(87((15315lt=(+2(

+amp+amp(amp(55$5$2gt( 21( Aamp+(amp+( )amp+(012$3+(B29(5$05$95($$2(5amp+(

199524(amp5215$(0+( 65ampamp7(85209(+2($1(87(15315lt=(+2(amplt( 29gt(51($51(amp9(2(25=(C(DD(0+(

E15amp+(Famplt2amp( G1$5(lt1lt$51(25amp=( HIJKH(Dlt1amp(15315lt=(+2(I(C2(CH(+5gt( )11$gt($511(02+(15315lt=(+2(

$1(87(15315lt=(+2(D5$$(3(lt5$$gt(02+(gt( 6lt=(511B(

L15gt( G1$5(lt1lt$51(25amp=(Aamp+( amp+(

HIJKH(Dlt1amp(15315lt=(+2(I(C2(CH(+5gt( )11$gt($511(02+(15315lt=(+2(

$1(87(15315lt=(+2($1(87($B(amp=amp( 5$Damp(+2(

M$$B(5lt9(-5$+( NO515(G1$5(219( L2+1(15ltB5gt(Aamp+(5amp+( amp$amp+(amp+(

1amp(91D(amp5$(Pamplt5$amp4( 8gtlt$34(1$amp54(5amp+(5120lt5$( $5amp=2amp()amp+(012$3+(B29(5$05$95( $$2(5amp+(19952Q(amp12152( 1+lt2amp(

$1(87(15315lt=(+2($1(87(15315lt=(+2( $1(87(15315lt=(+2(

Table 8 Factors limiting production at major razorback sucker facilities

$amp( )amp+(-0+1((2$(0amp1ampamp(-34amp( $amp()amp+( -(01$2(34+(546(amp(0amp(01amp(541(13( -741( 803(3amp41amp4(9((+ltlt1amp4(03(amp(44amp(2=(4(

+ltlt3$4(4(2amp4amp(014(1gt13=(43=( 1amp+(amp34amp( 803(3amp41amp4(1$4+(4(541(A$4B(amp+(+$C+(

7Bamp($244amp(lt(1313$4amp(B42( D1B( E41(A$4B(01$2(3+(B(66(1amp(amp+(2ampamp(

Eamp41(420141(464(1A1($$(lt6(4((2C+(amp+1( 803(3amp41amp4(1$4+(4(541(A$4B(amp+(+$C+(7Bamp(

E$$5(36( 803(3amp41amp4F(15amp(lt6(4(amp31amp$B($11(gt( 1$4(amp(ampltlt3amp4(03(amp(44amp(lt1(amp5(lt6(

GC$+( 8221(420(3amp(4(6691A1amp(051((4(410$(+(4( 661(1amp+541(020amp(4(=0(0amp+(3$F(

20

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Table9Reportedandcalculatedgrowthratesfromtheliterature

Calculatedgrow

thratesbasedon

informationprovidedinliterature

aApproximationsofmaximum

grow

thpotential(basedon

average13 maximum

sizesiffishreportedatharvest

21

13

General Information on Factors that Affect Fish Growth

Growth in fish is extremely variable and is impacted by many different

physiological and environmental factors Growth rates are known to change with size and

age sex season activity level density amount13 of living space quality and quantity of food

genetics and temperature (Brett 1979) Growth experiments conducted at different times

of year can result in growth rates that are not comparable As fish become larger their

physiological13 potential to grow decreases making determination of growth rate dependent

on the size of the starting fish and the length of the experiment (Busacker et al 1990)

Genetic factors also have great potential to influence growth rate Some species have

strains13 and13 races13 that display vastly different growth potentials (Reinitz et al 1979) All of

these factors combine to make assessment of the individual factors controlling fish growth

difficult13

Water temperature is probably the most important variable affecting growth rate13

All of the basic functions that affect growth such as feeding digestion and metabolism are

temperature-shy‐dependent13 Growth13 is inseparably13 tied13 to13 bioenergetics13 and13 therefore13 also13

tightly tied to temperature When temperatures are below optimum daily temperature

fluctuations can stimulate growth Photoperiod is also commonly linked to water

temperature and can influence growth rates in fish (reviewed in Brett 1979)

Fish density13 is known to13 affect growth13 and13 can alter13 growth13 rates13 in several ways13

Fish that exhibit strong territorial behaviors13 or natural schooling tendencies13 will

experience reduced growth if densities are too high or too low (Brett 1979) Dominance

hierarchies where some fish feed more aggressively than others can also lead to high

variability13 in growth13 rates13 (Koebele13 1985) Crowded13 conditions13 also13 cause physical

interference13 between13 fish and13 poor water13 quality13 which13 reduces13 growth13 (Busacker13 et al13

1990) The effects of fish numbers space and feeding opportunity are frequently correlated13

and often13 difficult13 to distinguish (Brett13 1979)13

It is impossible to study the effects of environmental factors on growth without also

evaluating feed rations (Brett 1979) Amount of food quality of the diet particle size

number of feedings per day and time of feeding have all been shown to affect growth

(Busacker et al 1990) In controlled laboratory studies food is usually fed ad libitum13

22

13

(constantly available) and other variables are altered to assess impacts of environmental

factors13 on growth13 These studies13 are13 usually13 conducted13 in tanks13 or raceways13 because13

researchers must verify that food is constantly available to the fish which is difficult to do

in large pond environments where the fish and the bottom13 are often not visible (Busacker13

et al13 1990)

Specific Information13 o Razorback13 Sucker13 Growth

Variable13 growth

Growth in razorback suckers is naturally highly variable and may be a function of

their evolutionary history (USFWS13 2002)13 Minckley (1983) speculated that13 wide size

variation in a single cohort of razorback suckers may be adaptive with fast-shy‐growing13 fish

that13 reproduce at a young13 age surviving13 better in13 high discharge years and slow-shy‐growing13

smaller fish surviving better during drought periods This highly variable growth rate

makes rearing razorback suckers in a production setting difficult because fish from13 a single

cohort do not reach the target stocking size simultaneously One of the major tasks for

aquaculture is to maximize both individual growth and total production13 (Gerking13 1978)13

This becomes more difficult when the species being cultured exhibits highly variable

growth13 rates13 because of genetic influences as is the case with razorback13 suckers13

Razorback13 sucker growth13 is typically very13 rapid13 during13 the first13 year of life13 and then13

declines with age First year growth can be as low as 50 mm and as high as 350 mm (Valdez

et al13 1982 Minckley13 1983 Mueller13 1995) Razorback sucker13 grow rapidly13 for

approximately the first five or six years of life and then growth slows13 (McCarthy13 and13

Minckely 198713 Tyus 199813 Minckley et13 al 1991)13 Growth of older individuals in13 extant13 wild

populations is very13 low (Minckley 198313 Tyus 198813 Modde13 et al 1996)13 Wild growth13 rates

for mature adult fish in Lake Mohave based on PIT tag recaptures were often too small to

be accurately measured for both males and females over the time period of 1987-shy‐199713

(Marsh and Pacey 1998) This information suggest it will take substantially longer to rear

fish to13 increasingly13 larger13 stocking13 sizes (40013 ndash 500 mm TL) than it did to reach the target

size of 300 mm TL

Growth in ponds

23

13

One of the main strategies for maintaining genetic refugia and self-shy‐sustaining13

populations of razorback13 sucker in the lower Colorado13 River basin13 is to rear razorback13

sucker13 larvae13 in production13 ponds until they13 are13 a suitable13 size for stocking13 (USFWS13 2004)

Pond culture has proven useful to promote rapid growth of juvenile razorback suckers

(Kaeding and Osmundson 1989) Marsh (1994) reported that growth rates of razorback

suckers13 reared13 in golf-shy‐course13 ponds exceeded13 the13 best growth13 rates13 obtained13 under

intensive13 culture13 conditions13 at federal hatcheries13 especially13 during the13 first several years13

of life Growth rates in these semi-shy‐natural ponds are also comparable to estimated growth

rates13 of juvenile13 wild13 fish (McCarthy13 and13 Minckley13 1987) Modde13 and13 Haines13 (2005)

reported13 the13 greatest growth13 rates13 in the13 largest and13 deepest floodplains13 with13 the13 greatest

amount of submergent vegetation but excellent growth and survival of fish in a grow-shy‐out

pond is of little value if there is not an efficient way to collect the fish from13 the pond

(Kaeding and Osmundson 1989)

Temperature13

Bulkley and Pimentel (1983) used shuttle boxes in the laboratory to determine a

temperature preference13 for razorback suckers13 of 23-shy‐24degC13 In13 their13 studies13 razorback

suckers were found to avoid temperatures below 118 degC or above 286 degC Razorback

suckers at Bubbling Ponds Hatchery are more active in the spring and feed better as

photoperiod increases even prior to water temperatures rising (Frank Agygos personal

communication) Table 3 briefly summarizes water temperature data from13 each facility

Detailed seasonal water temperature profiles are not currently available for many

razorback grow-shy‐out sites13

Density13

Extensive studies have been conducted on commercially important species to

evaluate stocking densities and feeding rates that maximize production For these species

controlled experiments under laboratory conditions have established relationships

between temperature density and feed ration on growth (Brett 1979) but this information

is sporadic13 or non-shy‐existent for razorback suckers13 (Bays13 et al13 2005) Fish culturists13 with13

24

13

experience13 rearing13 razorback suckers13 typically13 have13 target stocking13 densities13 that13 they use

(Tables13 4 -shy‐ 5) These stocking densities have largely been determined over time by trial

and error These approximate stocking densities provide a good starting point for more

controlled13 types13 of replicated13 pond studies13

Feed ration

Razorback13 suckers are currently13 being13 fed a wide variety13 of prepared diets (Table 7)

that range from13 a slow-shy‐sinking salmon feed manufactured by Silver Cupreg to a spirulina

and krill-shy‐enhanced catfish feed made by Rangenreg Most locations are feeding 20 ndash 50

body13 weight per13 day13 Methods13 for culture13 of razorback sucker13 larvae13 in intensive13 settings13 at

fish hatcheries are well documented (Figiel 2005) and various larval fish diets have been

evaluated13 (Tyus and13 Severson 1990 Severson et al13 1992) but no standardized13 procedures

are used for feeding13 larval13 fish in13 intensive settings13

Razorback sucker larvae are also effectively reared in pond environments using

natural foods supplemented with larval fish diets and survival is high when no predators

are present13 (Mueller 2006)13 Growth rates for larval13 and early juvenile razorback13 suckers

may increase with pond fertilization Diet and physiological studies on wild razorback

suckers indicate that they feed on plankton as well as benthic organisms during their entire

life (Marsh 1987) Artificially fertilizing ponds may greatly increase production capacity

and growth rates for razorback13 sucker (Papoulias and Minckley13 1992) and warrants

further13 investigation13

Handling stress

Handling stress13 has13 been shown to13 influence growth13 rates13 Paukert13 et al (2005)

found that growth of bonytail chub was reduced by 26when compared with controls

after being13 repeatedly13 captured and handled in13 hoop13 nets13 Handling13 effects are likely13 to be

similar for razorback suckers that are repeatedly13 captured and sorted in13 a hatchery13 setting13

Razorback suckers that are handled at Willow Beach National Fish Hatchery will commonly

not eat for two weeks after handling (John Scott personal communication) This creates a

difficult situation13 for production13 facilities because13 fish13 need to be sorted to ensure13 large13

25

13

aggressive fish do not interfere with growth of smaller individuals but frequent handling

and sorting13 causes stress related reductions in13 growth13

Measuring Growth in Captive Fish

Weight is the traditional measure used to estimate growth or production in

aquaculture settings13 Groups of fish are typically13 weighed and an average individual13 weight13

is computed (Busacker et al 1990) Although this method is often logistically the easiest it

may not be the most informative for species with highly variable growth rates like

razorback suckers especially when target lengths must be reached before fish can be

stocked Weight can also be highly influenced by things like stomach fullness or

development of gonads (Busacker et al 1990) Condition factor or relative weight can also

be used to assess growth of fish but these tools may be more robust predictors of fecundity

than of growth (Anderson and Neuman 1996) For some species sexes need to be

distinguished because males and females may differ in morphology (Anderson and

Neumann 1996) Mueller (2006) analyzed growth rates based on PIT tag recaptures of 86

razorback suckers13 in High13 Levee Pond13 and13 found13 that differences13 in growth13 do not appear13

to occur until fish are over 450 mm TL at which time growth rate in males slows while

females continue to grow at a slightly higher rate This would indicate that sex may not be

an important factor to consider when examining growth rates unless the target grow-shy‐out

size is above 450 mm TL

The best measures of growth are often determined from13 the length and weight of

individuals rather than from13 groups of fish (Anderson and Nuemannn 1996) because

individual growth rates give better estimates of confidence and variance (Busacker et13 al

1990) Length frequency analysis or recapture of previously marked individuals of a known

size is likely to yield the most useful information for razorback sucker growth The success

of any of these methods depends on proper sampling procedures that are representative of

the population as a whole (Busacker et al 1990) Sampling methods that are known to be

size-shy‐biased such as trammel nets (Mueller et al 2004) or cast nets should not be used when

trying to measure growth rates13

26

13

Conclusions

For razorback sucker survival is largely associated with stocking size Additional

focused13 research13 is therefore13 needed to13 identify13 ways13 to13 increase13 growth13 rates13 of captive-shy‐

reared13 razorback sucker Growth13 rate13 in fish is controlled13 by many factors including fish

size and age temperature density and feed ration which can all be highly correlated

Growth of razorback suckers is also inherently variable which makes the task of identifying

the key factors that13 affect13 growth in13 captivity even more difficult The focus at most

razorback rearing facilities13 is production so the13 types13 of data that are13 collected13 are13 often

insufficient for detailed13 evaluations13 of individual rearing13 practices13 on growth13 Surveys of

existing13 razorback sucker13 rearing facilities indicate that culture methods vary widely and

the types of growth data13 that13 are collected are not13 standardized13 Replicated studies with

detailed information on rearing location water temperature initial stocking size stocking

density and the sizes of all fish at harvest are needed in order to compare the effects of

individual rearing practices on growth This type of research will ultimately provide both

time and cost-shy‐savings to production facilities by reducing the amount of time necessary13 for

razorback sucker to reach stocking size improving overall production efficiency

Optimum13 rearing densities for razorback sucker larvae and juveniles remain to be

determined Current stocking densities will be very useful as starting point for more

detailed studies and although optimum13 rearing densities are likely to be site-shy‐specific13

replicated studies on density will provide a valuable reference for hatchery managers

Frequency13 of sorting is another13 area that needs13 further13 research Frequent

handling13 and13 sorting13 can13 cause13 stress-shy‐related13 reductions13 in growth but not sorting can

create dominance hierarchies that further reduce growth rates of subordinate individuals

The effects13 of sorting13 on overall fish growth13 in both13 pond and13 intensive13 culture13

environments warrant further investigation Research techniques for these types of

experiments are well understood and typically utilize a matrix of replicate ponds per

variable (Bays et al 2005) In every case accurate and complete records of sampling

procedures and data collection are needed in order to interpret data and make inferences

about13 growth rates (Busacker et13 al 1990)13

27

13

Additional research is also needed to evaluate long-shy‐term13 survival of stocked fish

reared in ponds compared to fish13 reared13 in intensive13 culture13 facilities13 Exercise13

conditioning13 and predator-shy‐recognition training may also increase survival of stocked fish

and be more economically feasible than rearing fish to increasingly larger sizes prior to

stocking13 The success13 of traditional fish hatchery programs is measured largely by the

number of fish stocked but hatchery programs for endangered species must measure

success in terms of long-shy‐term13 survival and species recovery (Brannon 1993 Anders 1998)

A specific list of research recommendations follows

Specific Research13 Recommendations13

bull Use replicated studies13 to establish optimum stocking13 densities13 for ponds13 and

tanks13 that can be used as13 a starting13 point for site specific refinement

bull Determine if sortinggrading13 improves13 overall growth rates13 in both ponds13 and

intensive culture facilities13

bull Investigate the use of artificial fertilizers13 to improve growth of both juvenile

and adult razorback suckers13 in ponds13

bull Determine if the razorback sucker diet gives13 better growth rates13 than cheaper

catfish or salmon feeds

bull Evaluate growth rates13 and production potential of new intensive culture

methods13 such as13 large circular tanks13

bull Evaluate13 long-shy‐term survival of fish produced from raceways13 and circular tanks13

compared to fish reared in ponds13

bull Evaluate more effective means13 of treating13 fish diseases13

bull Evaluate factors13 other than size that may increase post-shy‐stocking13 survival such

as13 exercise conditioning13 predator recognition training or rearing13 under more

natural settings13

28

13

II The Effect of Disease Treatments on Razorback Sucker

Growth

Section13 SummaryFormalin copper sulfate potassium permanganate and13 salt are all chemicals commonly13 used13 to13 treat13 Ichthyophthirius multifiliis outbreaks in captive razorback sucker (Xyrauchen13 texanus) Weexposed 190 juvenile13 razorback suckers (127 ndash 26 mm TL) to13 5 5-shy‐day treatments with13 each13 chemical to evaluate the effects13 these chemicals13 may have on growth Fish grew an average of23513 mm TL13 during the month13 study period Fish treated with formalin grew on average13 29mm TL (03 mmday) while fish treated with copper had the lowest growth averaging 20 mmTL (021 mmday) No significant differences in13 growth were observed among fish treatedwith any of the chemicals compared to untreated fish (pgt005) Reductions in growth13 as aresult of repeated chemical treatments are not likely the cause of differences in growth ratesamong13 facilities that raise razorback suckers Repeated chemical treatments may13 have otherimpacts to overall13 fitness or long-shy‐term survival but13 these effects were not13 evident13 in our study

29

13

Introduction

Preservation13 of razorback sucker13 (Xyrauchen texanus) currently13 depends on captive13

rearing and stocking programs until permanent solutions to factors that prevent wild13

recruitment are found Low survival of stocked razorback suckers (Brooks 1986 Marsh

and Brooks 198913 Marsh and Pacey13 2005) has caused target13 sizes for stocked fish to

steadily increase in efforts to reduce predation mortality (Marsh et al 2005 Schooley and

Marsh 2007) Rearing fish to larger sizes at hatcheries comes with increased costs and

creates the need to evaluate husbandry and rearing practices that may affect fish growth

Formalin copper sulfate potassium13 permanganate and salt are all chemicals

commonly used at razorback sucker rearing facilities to treat outbreaks of the protozoan

parasite13 Ichthyophthirius multifiliis ldquoIchrdquo is one of the most pathenogenic diseases of

cultured13 freshwater13 fishes (Matthews13 2005) and causes large13 losses in captive13 populations13

of endangered razorback sucker Each of these chemicals used to treat Ich only kill the free-shy‐

swimming life stage of the parasite13 requiring13 repeated doses over several13 days depending13

on water temperature These chemicals treatments are needed to prevent loss as a result

of disease outbreaks but the cumulative effects repeated disease treatments have on

growth13 are13 unknown

Copper13 sulfate13 has13 been shown to13 significantly13 reduce13 growth13 of channel catfish13 in

production13 ponds (Rabago-shy‐Castro13 2006) but it is unknown whether13 razorback suckers13

experience similar reduced growth following copper treatment Quantifying the impacts of

disease treatments on growth will help to interpret the wide differences in growth rates

observed13 at various13 razorback sucker13 production13 facilities13 throughout the13 southwest

(Ward et al 2007) If one chemical is found to have less detrimental impacts on growth

than another then it may be preferred for use as a disease treatment We evaluated growth

rates13 of razorback suckers13 under13 replicated13 and13 controlled13 conditions13 to13 assess13 effects13 of

repeated formalin copper sulfate and potassium permanganate and salt treatments on

growth13

Methods

We captured 190 juvenile razorback suckers from13 ponds at Bubbling Ponds Fish

Hatchery AZ using hoop nets or cast nets All fish were of the same age class and

30

13

averaged 179 mm total length (TL) (range13 = 127 ndash 262 mm TL)13 These fish were13 offspring13

of captive13 razorback sucker13 broodstock held13 at Dexter13 National13 Fish Hatchery13 NM13 (2007

year class) All fish were tagged with passive integrated transponder (PIT) tags and

quarantined for one month prior to the experiment to allow fish to recover from13 tagging

and become accustomed to being held in circular tanks

At the beginning of the study all fish were weighed measured and scanned for

individual tag numbers with 19 randomly selected fish placed into each13 of 10 8-shy‐foot

diameter circular tanks (Figure 2)13 Each13 tank contained13 two13 airstones13 and13 an13 individual

biofilter with a recirculating water pump (31 litersminute) that had been operating for

at least 1 month prior to the experiment to allow bacterial colonies to become

established Two tanks were designated as a control and did not receive any chemical

treatments while the other eight tanks received formalin copper sulfate potassium13

permanganate or salt treatments at two week intervals (two tanks per chemical

treatment) Formalin copper sulfate and potassium13 permanganate were treated at 1 part

per million (ppm) and salt was applied at 30 parts per thousand (ppt) These treatment

rates are commonly used to treat13 razorback13 suckers for ich at Bubbling13 Ponds Fish13

hatchery (Frank Agygos personal communication)

Figure 213 Photo ofexperimental tankswith individualbiofilters and aeration

31

13

Each treatment consisted of a series of doses applied on Wednesday Thursday and

Friday with a 90water change between each dose Biofilters were removed from13 all

tanks and held in a separate holding facility during treatments and then replaced on the

Monday following treatments after a 90water change This schedule allowed fish to be

exposed to chemical treatments for 5 consecutive days without water quality deteriorating

This 5-shy‐day chemical treatment was repeated every two weeks from13 July to October (97

days)13 for a total of 5 5-shy‐day treatments Water temperature in the treatment tanks ranged

from13 13degC (55degF) to 32degC (91degF)

Fish were fed a fixed ration of commercial razorback diet (Silvercup 4mm13 pellet)

once daily13 (2 percent body13 weight per day13 as calculated13 by13 average initial fish weight)13

At the end of the experiment all fish were again weighed measured and scanned for

individual tag numbers Growth of fish in each treatment group was compared using

analysis of variance (ANOVA) Any mortalities13 that occurred during the13 study13 were13

replaced with previously quarantined fish of equivalent size to maintain equal densities in

each13 tank13 but growth13 data was13 only13 recorded for fish which13 survived13 the13 entire13

experiment

Results

Fish at the13 start of the experiment averaged 179 mm TL (Range13 = 127 ndash 262 mm)

with no significant differences in fish length among treatment groups (F(4189) = 00183 p

gt 0999 ANOVA) On average fish grew 235 mm TL (024 mmday) during the 3 month

study13 Fish in tanks13 treated with formalin had the highest growth averaging 29 mm TL (03

mmday) while fish in tanks treated with copper had the lowest growth averaging 20 mm

TL (021 mmday) Fish in the control tanks averaged 213 mm TL in growth (022

mmday) (Figure13 3)13 Formalin-shy‐treated fish grew13 significantly faster than13 any other

treatment group but no13 significant differences in growth13 in length13 or weight were13

observed among fish treated with any of the chemicals compared to untreated (control)

fish (pgt005 ANOVA)

32

13

Figure 313 Average growthof razorback suckersexposed to a series of 5 5-shy‐day chemical treatmentsover a 97-shy‐day13 periodError bars representstandard error

Discussion13

Growth13 rates13 observed13 in our study13 (021 ndash 03 mmday) are low compared to those

reported13 in other13 studies13 of razorback sucker13 growth13 (0213 ndash 18 mmday) (Ward et al

2007) Using recirculating water systems for our study required filters to be removed and

replaced during treatments Stress to fish caused by removing and replacing filters within

the tanks as well as repeated water changes may have led to overall higher stress and

reduced growth rates compared to those reported for unconfined fish Growth in fish is

highly variable and is affected by many different physiological and environmental factors

including fish size density temperature amount of space and food (Brett 1979) We

strived to control each of these factors but other factors may have also influenced growth

in our experimental tanks During mid-shy‐summer water temperatures in the treatment

tanks reached 32degC (91degF) At these warm13 temperatures fish are very susceptible to

bacterial13 infections13 The slightly higher growth exhibited by fish in the formalin and

potassium13 permanganate treatments may have been the result of these two chemicals

33

13

being effective at controlling bacterial infections The differences in growth we measured

among treatment groups were not statistically significant and do not appear13 biologically13

meaningful during the relatively short duration of this study (97 days) although the

cumulative effects of slightly reduced growth could be biologically meaningful over longer

time frames

Reductions in growth13 as a result13 o repeated chemical treatments are not likely the

cause of differences in growth rates among facilities that raise razorback suckers

Repeated chemical treatments may have other impacts to overall fitness or long-shy‐term13

survival but these13 effects13 were13 not evident in our study It is more likely that the parasite

outbreaks themselves are the cause of different growth rates among razorback rearing

facilities rather than the chemical treatments used to treat the parasites We recommend

that hatchery managers continue to use the chemicals that are most effective at controlling

ldquoIchrdquo13 at their individual13 facilities

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower Colorado Rive Multi-shy‐species13

Conservation Plan under Work Task C10 We thank Ty Wolters and Tom13 Burke for their

support of this research and Frank Agygos and Dave Billingsly of the Bubbling Ponds Fish

Hatchery13 for their13 technical assistance13 and13 help with13 collecting13 fish

34

13

III13 Razorback Growth Rates at Bubbling Ponds ndash 2009-shy‐2011

Section13 SummaryExperimental studies at Bubbling Ponds Fish Hatchery AZ have strived to understand

factors that affect razorback sucker growth in captivity and identify ways to improve growthrates and maximize size at release Rather than performing experimental studies that wouldrequire major13 rearrangement (and likely reduced production)13 of hatchery operations our13 studies13 used normal variation in production techniques13 and practices13 to isolate factors13 thatmay modify growth rates

Our initial work identified razorback13 growth rates in13 lined ponds at standard fishdensity as 026 to13 028mmday (789 to 843 mmmonth) No significant differences in growthrate were observed among fish that had been in the pond only during the winter13 periodcompared to fish that had been in the pond the entire year indicating that water temperatures13 at Bubbling Ponds are high enough to allow fish to incorporate feed effectively year-shy‐roundHowever these growth rates are lower than most values reported from the literature fromnatural or semi-shy‐natural pond environments No significant differences in13 growth rate wereobserved13 between large and13 small fish13 within the 150 ndash 29 mm TL13 size range Additional worksuggests13 that razorback suckers13 tagged at over 300 mm TL had reduced growth rates (024mmday 73 mmmonth) as would be expected according to a typical Von13 Bertalanfy growthcurve although growth rates13 were only slightly less13 than the average growth rate for thehatchery (027513 mmday 82513 mmmonth)

Sorting13 to13 separate small fish from large fish after the first year of growth is practicedesigned13 to allow smaller fish to ldquocatch uprdquo to larger fish We found that13 this technique doesappear to13 improve growth rates of smaller fish Growth rates of sorted small razorback suckers(029 mmday 87mmmonth)13 were equal to that13 of larger13 fish (028 mmday 8413 mmmonth)indicating that sorting may have helped to offset their original slower growth trajectory

Bubbling Ponds Fish Hatchery grows razorbacks in 6 long deep ponds lined with heavyplastic 2 long deep13 earthen13 (unlined) ponds and three wide shallow earthen ponds The wideshallow ponds13 have historically produced very large fish at low density but have been found tomaintain much lower fish numbers than deeper ponds We found13 that growth13 rates ofrazorbacks kept at high density (4-shy‐700013 fish)13 in a wide shallow pond grew extremely slowly(024 mmday 726 mmmonth) This growth rate is among the slowest of any fish over theyears of our study and demonstrates that13 though the large ponds may produce large fish at lowdensity13 they are unable to overcome high13 fish13 densities

Finally one of the major factors influencing13 fish13 growth13 in hatcheries is disease onemajor summer-shy‐time disease at13 Bubbling Ponds is the ectoparasite Ich (Ichthiopthirusmultifiliis) To investigate the impact Ich has on razorback growth we eradicated fish from thespring and water conveyance ditch that supplies13 water to the hatchery using Rotenone This13 restoration effort was fairly short-shy‐lived (Ich returned to the hatchery within four months) but

35

13

growth13 rates of fish13 reared for four months without Ich present (031 mmday 92 mmmonth)were significantly higher than the following 8 months of growth for those same fish (022mmday 65 mmmonth) This disease-shy‐free growth rate is in fact faster than any13 otherprevious growth rates observed at the hatchery in our study

We conclude that growth rates at the Bubbling Ponds Fish Hatchery are likely as highas possible given the pond densities required to13 meet production goals and the Ich-shy‐infestedwater13 that feeds the facility Sorting practices are successful in helping as many fish as possiblereach stocking length as fast as possible Unlined ponds may be able to grow large fish at lowdensities but whatever factors allow for that growth13 are not able13 to overcome13 high fish densityThus the large lower ponds at Bubbling Ponds may be better utilized via renovation to13 deepenand line them

Disease is the most important factor limiting growth as may be expected to be the caseat many13 hatcheries While the spring renovation was not13 a complete success13 the dramaticreduction of fish populations in that habitat was enough to dramatically13 reduce13 the13 occurrenceof Ich at the hatchery13 Such open spring13 systems feeding a hatchery are a misfortune that canbe expected to transmit disease so we suggest that renovating the spring again to combat13 IchImproved techniques to divert water from13 the springs and more throuough treatment ofstream-shy‐side vegetation may improve the success of chemical treatment Successful renovationwould likely both improve growth rates and reduce chemical costs associated with treating Ichoutbreaks Even13 if complete renovation13 is impossible or impractical an13 effort to reduceinvasive fish density in the springs13 which act a vector for the parasite(and thereby reduce thelikelihood of13 Ich being transmitted into ponds) may still13 show dramatic improvements

36

13

Introduction

Conservation efforts13 for razorback sucker13 (Xyrauchen texanus)13 currently13 depend on

captive rearing and stocking programs Low survival of stocked razorback suckers (Brooks

1986 Marsh13 and13 Brooks13 1989 Marsh13 and13 Pacey13 2005) has13 caused13 target sizes for stocked13

fish to steadily increase in efforts to reduce predation mortality13 (Marsh13 et al13 2005

Schooley and Marsh 2007) Rearing fish to larger sizes at hatcheries comes with increased

costs and creates the need to evaluate husbandry and rearing practices that may affect fish

growth13 We evaluated growth13 rates13 of individual razorback suckers13 in ponds13 at Bubbling

Ponds Fish Hatchery13 using Passive Integrated13 Transponder (PIT) tags13 to13 obtain13 precise

growth information for individual fish so that valid comparisons of growth rates as related

to rearing practices can be made

Due to the critical nature of the razorback sucker stocking program we did not

design experimental studies that would require major rearrangement and potentially

reduce production of hatchery operations Instead our studies used normal variation in

production techniques and practices to isolate factors that may modify growth rates

Though this methodology dramatically limits replication and may limit our ability to

directly13 attribute13 differences in growth13 rates13 to13 the13 variables13 we13 investigate13 we13 were13 able13

to accomplish research goals without altering hatchery operations or impacting

production

From13 2009 through 2011 we conducted a series of observational13 growth13 studies to

determine growth rates of individual razorbacks at Bubbling Ponds The first set of

experiments included13 identifying13 growth13 rates13 in lined13 and13 unlined13 ponds determining

growth13 rates13 of fish at different13 sizes13 in13 relation13 to sorting13 practices and monitoring

razorback growth rates after removing the source of the ectoparasite13 Ich (Ichthiopthirus

multifiliis) from13 the hatchery water source13

Razorback growth rate in lined ponds

Our first growth study documented individual growth rates at normal density in 11

million gallon lined ponds13 over two13 years13 This is the standard13 grow-shy‐out process for

razorbacks13 at Bubbling Ponds We monitored growth of fish for a variety13 of sizes and13 the13

37

13

amount of time in a pond during the growing season These13 data give a snapshot of growth13

rates13 at the13 facility13 and13 provide13 the basis for comparisons throughout our study

Growth rate13 in an unlined pond

In addition13 to 6 ponds lined with heavy plastic13 sheeting13 Bubbling Ponds Fish13

Hatchery maintains two narrow and deep (same dimensions as lined ponds13 Figure13 4)13 and13

three large13 shallow unlined ponds These earthen13 ponds typically have vegetation and

associated aquatic invertebrates that may better simulate natural environments by

providing cover and improved food diversity or quality Therefore these unlined ponds

may be expected to produce higher growth rates and potentially improved survival that is

more similar to growth rates observed in more natural grow-shy‐out facilities13 Historically13 the13

large13 shallow13 ponds have produced very large fish when13 utilized at low13 fish density13 The

narrow13 deep earthen13 ponds are13 used to grow13 fry13 at high density in their first13 year of life

The major downside to unlined ponds is the difficulty in harvesting fish where a lined

pond might take 8-shy‐1013 people13 a half13 day13 to13 harvest13 lined13 ponds13 require13 intensive13 weeding13

to allow seines to be pulled and therefore require many more personnel-shy‐hours13 In addition13

to harvest challenges the shallow earthen ponds tend to suffer from13 dissolved oxygen

crashes during the summer Unlined ponds also may maintain higher13 populations13 of non-shy‐

target species such as bluegill sunfish mosquito fish and bullfrog tadpoles We measured

growth rates of suckers in a large shallow earthen pond for comparison to growth in lined

ponds13

Figure13 4 Lined13 and13 earthen ponds13 of similar dimensions (approx 1000000 gallons first

and second panels) and a large13 shallow13 earthen13 pond (third panel)

38

13

Effect of sorting on growth

Razorback13 suckers13 are13 currently13 sorted13 after their first13 year of growth13 They are13

typically removed from13 one of the13 upper earthen13 ponds and13 split into13 two13 lined13 ponds for

subsequent grow-shy‐out13 The larger13 fish (gt approximately 140 mm) are placed into one pond

and the smaller individuals in another It is possible that the larger fish were more

aggressive or adept13 at taking food so this sorting process is intended to allow smaller fish

to improve their growth rate

Effect of Ich on razorback sucker growth rates

We13 evaluated13 growth13 rates13 of razorback sucker13 in the13 presence13 and absence of the

ectoparasite13 Ich (Ichthiopthirus multifiliis) Ich outbreaks can occur in wild populations13 but

hatcheries13 have13 proven excellent locations13 for Ich because13 of very high fish densities13 which13

facilitate13 the13 transfer13 of Ich13 between13 fish This common fish parasite causes direct mortality13

to razorback13 suckers as well13 as secondary bacterial13 infections13

The open spring and13 ditch13 which13 provides water to the Bubbling13 Ponds Hatchery

has long13 been infested with mosquitofish (Gambusia affinis) that harbor13 the13 Ich parasite13

and allow13 it13 to enter the hatchery with incoming13 water13 The solution13 to13 the13 Ich problem13

was to remove the mosquitofish host using13 Rotenone Razorback13 sucker growth13 rates were13

then tracked in13 the absence of this parasite for 4 months and compared with growth rates

after Ich returned to the pond and from13 previous years

Methods

Razorback growth rate in lined ponds

On May 14 2008 141 razorback suckers were tagged with 12 mm PIT tags (1342

kHz) and placed in Pond 3 (approximately 1100000 gallons13 Figure13 4)13 at Bubbling13 Ponds

Fish Hatchery Fifty-shy‐three of these tags were recovered two months later when a large

Ichthyophthirius multifilis (Ich) outbreak killed many fish in the pond On October 15 2008

an additional13 145 PIT tagged13 fish were13 also placed into Pond13 3 On13 May13 14 2009 Pond13 3

was harvested and a total13 of 141 PIT tagged fish were recovered13 Of the tagged fish13 26 fish

had13 been13 in the13 pond since May13 of 2008 (378 days13 o growth) and 115 had been13 in13 the

39

13 40

pond since October13 15 2008 (211 days13 of growth) Numbers of fish in Pond 3 after the Ich

outbreak and for the majority of the period of growth were between 3 000 and 4000 fish

A Hobotempreg temperature13 logger13 was13 also13 installed13 in Pond 3 one meter below the water

surface13 near13 the13 outflow and13 recorded water temperature every 3 hours to allow analysis

of the effects of water temperature on growth rate (Figure13 5) This Hobotemp data is

representative of other pond temperatures throughout this study

In a second experiment 210 adult13 razorback suckers13 were13 PIT tagged13 on13 May 14

2009 and13 placed13 into13 Pond13 3 upper to13 evaluate13 growth13 rates13 of larger13 razorback suckers13 at

Bubbling13 Ponds Hatchery13 under current13 rearing13 conditions13 Size of these fish at tagging13

was (mean = 285 mm range = 205 ndash 396 mm) These fish remained in the pond for 257

days and were harvested on Jan 25 2010 to provide information on growth rates of larger

razorback suckers13 under13 current rearing conditions

Figure 513 Temperatures (degC) inrearing pond at BubblingPonds Hatchery from July toSept 2009 (top graph)13 andfrom Nov to Dec 2009 (Lowergraph) Temperaturesrecorded with a Hobotempregremote data logger13 every 3hours

13

Growth rate13 in an unlined pond

To document razorback sucker growth in earthen ponds we introduced13 225 tagged13

razorback suckers13 into13 Pond13 1 lower13 (Figure 4) in February 3 2010 Additional tagged fish

from13 other studies were added to the pond throughout the growing season and the density

of 1 lower reached a maximum13 of nearly 7000 fish in early summer 2010 Density was

reduced to approximately 6000 fish by capturing fish with hoop nets on June 3 2010 54 of

these fish were tagged fish and returned to 1 lower after being weighed and measured The

pond was harvested on January13 2713 2011 and a total13 of 254 tagged fish out13 of 4296 fish

total were removed from13 the pond The pond was harvested on January 27 2011 (358 days13

of growth) and the tagged fish were weighed and measured Total number of razorbacks in

the pond at harvest13 was 4296

Effect of sorting practices on growth rates

On March 1113 200913 Pond13 5 upper was13 harvested13 and13 split into13 two13 separate13 groups

Two hundred of the smaller fish (average size = 122 mm TL) were PIT tagged and placed

into13 Pond13 7 upper and13 200 of the13 larger13 fish (average = 160 mm TL) were PIT tagged and

placed int Pond13 8 upper Density13 in Pond13 7 was13 4500 fish and13 in Pond13 8 there13 were13 6500

fish These ponds were then harvested after 1 year and growth rates were compared to

give information on the effects of current sorting practices Hobotempreg temperature

loggers were installed in13 Ponds 7 and13 8 during13 the13 grow-shy‐out period with13 water13

temperature recorded every 2 hours13 (Figure13 6)

Effect of Ich on razorback sucker growth rates

Bubbling Ponds spring was treated with Rotenone (CFT Legumine 5) at a

concentration of 2 ppm13 to remove all mosquitofish from13 the spring The treatment

consisted of two treatments 6 hours in duration on two consecutive days (April 12 -shy‐ 13)

using13 drip13 stations13 and13 backpack sprayers13 followed13 by13 an13 additional 6 hours13 of

detoxification using sodium13 permanganate Although 12 mosquitofish were captured in the

spring pond the week following the treatments subsequent minnow trapping (20 traps

checked13 daily13 for 3 weeks) did not capture any additional fish until August 11 2010 when

41

13

juvenile mosquitofish were again detected in the spring pond Minnow traps have

subsequently been set daily with several hundred individuals removed To evaluate if Ich

was also again present in the spring we captured 15 mosquitofish from13 the spring pond on

three separate days and placed them13 in an aquaria at 25 degC with 5 longfin dace known to be

free of Ich These fish were monitored for 2 weeks with no signs of Ich developing This

indicates that even though mosquitofish have returned to the spring pond the parasite is no

longer present13 although how13 long13 this condition13 will13 persist13 is unknown13

On May 1113 201013 200 juvenile razorback13 suckers were harvested out13 of Pond 5

upper (2009 year Class from13 Dexter National Fish Hatchery) and were PIT tagged and

placed into Pond 8 to evaluate if growth rates at bubbling ponds hatchery have improved

following the renovation of the spring and the removal of the Ich parasite Unfortunately13

on Sept13 8 2010 Ich was13 again13 detected13 in Pond 8 and the pond was immediately seined

and 74 tagged fish were measured to obtain growth information for the 4-shy‐month period

during13 which13 the13 pond13 was13 Ich-shy‐free13

Figure13 6 Temperatures (degC) in rearingponds 7 and 8 at Bubbling Ponds Hatchery13 from March 2009 ndash March 201013 pond 7(top13 graph)13 and13 pond 8 (Lower13 graph)13 Temperatures recorded with a Hobotempregremote data logger every 3 hours

42

13

Results

Growth in Lined Ponds

Razorback suckers13 that had been13 in13 Pond 8 upper for the13 entire13 year13 grew an13

average of 0263 mmday (789 mmmonth) and razorback suckers that had been in the

pond for 7 months (Oct -shy‐ May) grew13 on13 average of 028 mmday (843 mmmonth) (Figure13

7) These growth13 rates13 did not significantly13 differ Fish density13 in Pond 3 during13 the13

majority of the growth period was13 00032 ndash 00036 fishgallon13 Additionally no13 significant

differences in growth rate were observed between fish smaller than 210 mm TL and fish

larger than 210 mm TL when all recaptured fish were combined

We also measured the growth rate of very large fish in a lined pond On Jan13 2513 201013

156 adult fish with PIT tags were recovered from13 Pond 3 upper13 These fish were13 in the13

pond for 257 days and experienced an average13 growth13 rate13 of 024mmday or 73

mmmonth (Figure13 7)13 This growth13 rate13 is slightly13 lower13 than13 the13 average13 growth13 rate13

observed13 at Bubbling13 Ponds Hatchery in other studies (0275 mmday 825 mmmonth)

but may not be biologically meaningful We would expect larger13 fish to13 have13 reduced

growth rates according to a typical Von Bertalanfy growth model (Bertalanffy 1957) but it

appears that13 over the size range we evaluated (300 -shy‐ 450 mm TL) growth rates have not

slowed significantly compared to that of smaller13 fish grown at Bubbling Ponds13 Hatchery

Growth13 of razorback suckers13 is known13 to13 slow as13 fish reach13 larger13 sizes but it appears13 this13

reduced growth rate may not really start to be biologically meaningful at Bubbling Ponds

Hatchery13 until razorback suckers13 exceed 450 mm TL

Growth in unlined ponds

Growth13 rates13 for the13 fish recaptured13 during13 the Pond 1 lower13 thinning13 (120 days13 in

the pond) was 024 plusmn 003 mmday (729 plusmn 090 mmmonth) (Figure13 8)13 Fish13 that were13 in

the pond for nearly the entire year grew13 an13 average13 of 024 plusmn 001 mmday (726 plusmn 027

mmmonth) These growth rates are surprisingly the lowest measured growth rates for

any part of our study and differ significantly from13 every other measured growth rate

except very large13 fish (Figure13 9)13 Separating13 out13 large fish that13 were in13 the pond for the

entire year makes no difference fish that were added to the pond at TL lt300 mm grew

43

13

Gro

wth

Rat

e (m

md

ay)

020

026

032

0244 plusmn 001 mmday (733 plusmn 028 mmmonth) and and those with TL gt= 300 mm at the

start of the experiment grew 022 plusmn 003 mmday (651 plusmn 101 mmmonth)

Razorback Growth Rates in Lined Ponds

Figure 7 Growth ofrazorback suckers in(mmday plusmn standard error)in Pond 8 upper in 2008-shy‐2009 An ANOVA did notdetect any significantdifferences

7 Months Full Year 300+ mm fish

Effects of sorting on growth

One hundred and seventy five tagged razorback suckers were recovered from13 Pond

8 upper13 on March13 24 2010 (378 days13 of growth)13 These were13 the13 larger sorted13 fish (gt140

mm TL) that came out of Pond13 5 on March13 11 2009 One13 hundred and13 twenty13 two13 tagged13

razorback suckers were also recovered from13 Pond13 7 upper on March13 31 2010 (385 days13 of

growth)13 These were13 the13 smaller sorted13 fish (lt140 mm TL) that came out of Pond13 5 on

March 1113 200913 No significant differences in growth rate (mmday) were observed among

larger fish in Pond 8 and smaller fish in Pond 7 (pgt005 ANOVA) (Figure 10)13 indicating

that13 sorting may have helped to offset the original slower growth trajectory of the smaller

fish Temperatures of Ponds 7 and 8 upper remained similar throughout the year13 (Figure

5)

44

13

13

13

Gro

wth

Rat

e (m

md

ay)

Gro

wth

Rat

e (m

md

ay)

020

026

032

020

026

032

Razorback Growth in an Unlined Pond

Figure 8 Growth of razorbacksuckers (mmday plusmn standard error) in Pond 1 lower (an unlined pond)in 2010-shy‐2011 An ANOVA did notdetect any significant differences

6 Months 12 Months lt 300 mm Fish 300+ mm Fish Growth Growth

Lined vs Earthen Ponds 1 year of growth

Figure 9 Growth of razorbacksuckers (mmday plusmn standard error) in lined and unlined ponds A t-shy‐test13 did not detect a significantdifference

Lined Pond Unlined Pond 1 Yr Growth 1 Yr Growth

45

13

Effect of Sorting G

row

th R

ate

(mm

day

) G

row

th R

ate

(mm

day

)

032

020

026

032

020

026

Smaller Fish Larger Fish

Effect of Ich

Figure 10 Average growthof razorback suckers(mmday plusmn standard error)that were size-shy‐sorted intosmall fish (pond 7) and largefish (pond 8) populations At-shy‐test did not detect asignificant difference

Figure 11 Average growth ofrazorback suckers (mmday plusmnstandard error) after Ich wasremovd from the hatcheryrsquos springand after Ich was again detected inthe pond The growth rate withoutIch is significantly higher than boththe rate after Ich and the ourstudyrsquos average annual growth ratein lined ponds (ANOVA p =00003)

Growth without Ich Growth With Ich Average Annual 4 months 4 months Growth Rate

46

13

Effect of Ich on razorback sucker growth rates

Seventy-shy‐four13 tagged13 razorback suckers13 were13 recovered from13 Pond 8 on September

15 2010 These fish had13 been13 in the pond for 4 months and experienced a growth rate of

032 mmday or 97 mmmonth (Figure13 11)13 This growth13 rate13 is significantly higher (p =

005 two sample t-shy‐test) than the mean growth rate for the same group13 of tagged fish after

Ich detection (022 mmday or 65 mmmonth) and significantly higher than any other

individual growth13 rates13 observed13 to13 date13 at Bubbling13 Ponds Hatchery13 (Figure13 11)13 If this13

growth13 rate13 were13 extended throughout13 the entire13 year13 fish on average from13 Ich-shy‐free13 ponds13

would be 16 mm longer than fish from13 ponds infested with Ich Studies conducted at

Bubbling Ponds hatchery in 2008 (Ward 2008) did not reveal any effects of the treatment

chemicals on razorback sucker growth rates so it13 is likely that13 the parasite outbreaks

themselves are causing reducing growth rates rather than the chemicals used to treat the

parasites13

Conclusions

Our results suggest that under typical hatchery operations (maximizing number of

fish produced)13 the growth13 rate13 of razorback13 suckers13 is relatively13 consistent at Bubbling13

Ponds hatchery13 at 02-shy‐03 mmday (6-shy‐9 mmmonth)13 but is lower than growth13 rates13 at

other13 facilities (02 ndash 18 mmday Ward et al 2007)13 This growth13 rate13 has13 been13 constant in

both lined and unlined ponds and at all fish densities we were able to measure To achieve13

growth13 rates13 substantially higher than this will likely require13 significant changes in rearing

practices that may not be practical in order to reach numerical production13 goals

Temperature is a key variable in fish growth but seasonal growth patterns

described13 above13 (Figure13 5) demonstrate that water temperatures are high enough in

winter to maintain razorback growth Differences in water temperature by season

currently13 do not fluctuate more than 10degC at Bubbling Ponds because of the continuous

supply of water flowing through each pond (approx 225 gallonsmin) These high water

flows appear to keep pond temperatures within the thermal preference13 for razorback

suckers13 (1213 -shy‐ 28 degC Bulkley and Pimentel 1983) throughout the entire year with

temperatures rarely dropping13 below 16deg13 C (Figures 513 6)13

47

13

Fish density is another key variable in fish growth and though the number of fish in

a pond during our study ranged from13 3000 to 700013 fish we13 did not find any13 correlation13

between13 density and growth rate13 This might yield two conclusions First13 razorback

growth13 may be changed equally13 by13 densities13 at the13 hatchery13 (ie13 a density13 of 3000 fish in a

pond is as stressful13 for razorbacks as a density13 of 7000 fish) An alternative is that other

factors13 such as disease outbreaks have13 stronger13 control over fish growth13 than13 density13

Fish density13 would13 have13 to13 be13 experimentally manipulated to test13 this13 and hatchery

operations (producing the maximum13 number of fish) prevented our manipulating density13

in ponds for this13 work The trouble with manipulating density demonstrates the difficulties

associated with changing13 hatchery13 practices experimenting with density would have

prevented BPH from13 meeting13 production13 goals Given that the stocking of smaller

razorbacks has met with very little success perhaps BPH goals could be changed from13

producing 12000 fish at 300+ mm per year to a smaller number of very large fish each

year Growing13 fewer13 larger13 fish could potentially be accomplished in the same time frame

as more smaller fish but a better understanding of how density alters growth rate would

be required to be confident13 of this

The very slow growth13 in the13 earthen13 unlined13 Pond 1 lower13 was very surprising We13

had13 anticipated13 that the13 diversified diet13 cover and13 other13 habitat features13 provided by13

unlined ponds would yield dramatically increased growth rates However these traits were

not enough to offset high fish densities and in fact the unlined pond in our study13 suffered

mortality to bring densities down to that observed normally in lined ponds

Our data13 suggest13 that razorbacks13 sucker13 growth13 rates13 are13 higher in lined13 ponds13

However we13 think the reasons13 for the13 very slow growth we observed13 in the13 unlined13 pond13

in our study13 is instead13 linked13 to13 the13 usage13 of Pond 1 lower13 during13 the13 study13 rather13 than13

intrinsic13 slow growth13 in earthen13 ponds First the pond was at extremely high density for at

least part of the study The volume of Pond 1 lower has not been estimated but hatchery

managers suggest 1500-shy‐2000 fish is an appropriate number of individuals so this pond

was at a very high density for much of the experiment Second dissolved oxygen is often

very low in the13 large13 earthen13 ponds during the heat of summer much lower than that of

lined ponds This will both limit the number of fish that can survive in the pond and almost

certainly13 increases stress13 of these13 fish potentially13 reducing growth13 The DO crashes also13

48

13

limit the amount of feed hatchery managers can give fish in these ponds sometimes for

days or weeks at a time which further reduces growth during warm13 weather

Our data13 suggests that13 growth rates at the Bubbling13 Ponds Fish Hatchery are likely

as high as possible given13 the pond densities required to meet production goals and the Ich-shy‐

infested water that feeds the facility Sorting practices are successful in helping as many

fish as possible reach stocking length as fast as possible Unlined ponds may be able to

grow13 large13 fish at low13 densities13 but whatever factors allow13 for that13 growth are not13 able to

overcome high fish density The removal of invasive13 fis that act as13 a host for the13 parasite13

Ich fish from13 the Bubbling13 Ponds spring13 allowed the highest13 growth rate at 032 mmday13

(96 mmmonth) but that growth rate decreased again as Ich re-shy‐infested13 the13 hatchery13

Consistently13 achieving13 growth13 rates13 as high or substantially13 higher than13 this13 will likely13

require13 significant changes in rearing practices that may not be practical in order to13 reach13

numerical production13 goals

Two major changes that might result in higher growth rates are substantially

reducing fish density and modifying the way spring water is delivered to the facility (via

either repeated chemical treatments or enclosed concrete water diversions) to eliminate

Ich from13 the hatchery source water Other potential changes not address by our work

include13 flow-shy‐training razorbacks much previous literature including MSCP-shy‐funded13 work

on razorback suckers13 suggests13 that fish growing13 in flowing water will grow13 faster than fish

in still water (Jorgensen and Jobling 1994) Furthermore there are a wide variety of

potential benefits associated with growing13 fish13 in flowing13 water in addition13 to increased

growth13 rates13 (Davidson13 199713 Castro13 et al13 2011) Another option13 for increasing13 growth13

rates13 include13 changing to13 intensive13 culture13 in large circular13 tanks

Finally given that the stocking of smaller razorbacks has met with very little

success13 perhaps13 BPH13 goals13 could13 be13 changed from13 producing 12000 fish at 300+ mm per

year to a smaller number of very large fish each year Growing fewer larger fish could

potentially be accomplished in the same time frame as more smaller fish but a better

understanding13 of how density13 alters growth13 rate13 would13 be13 required to13 be13 confident of this

49

13

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower13 Colorado13 River Multi-shy‐Species13

Conservation Program13 (LCRMSCP) under Work Task C10 We13 thank Ty Wolters13 Tom13

Burke13 and Eric13 Volkman for their support of this research and Frank Agygos and Dave

Billingsly13 of the Bubbling13 Ponds Fish Hatchery13 for their willingness to participate in13 this

research13 and13 for their technical assistance We also thank the LCRMSCP fish group from13

Boulder City13 NV for their assistance with harvesting13 ponds and tagging13 fish13

50

13

Literature13 CitedAnders P J 1998 Conservation aquaculture and endangered species can objective science13

prevail13 over risk13 anxiety Fisheries 23(11) 28-shy‐31

Anderson R O and R M Nuemann 1996 Length weight and associated structural indicesPages 447 ndash 482 in B R Murphy13 and D13 W Willis13 editors13 Fisheries techniques13 2ndedtion American Fisheries13 Society13 Bethesda13 Maryland

Bain M B J T Finn and H E Brooks 1988 Streamflow regulation and fish communitystructure13 Ecology13 69382-shy‐392

Bays J H Zarbock R Whitman and T Murphy 2005 Conceptual design and managementof native13 fish refugia on the13 lower13 Colorado13 River In13 CL Spring13 and13 S Leoneditors Proceedings of two symposia Restoring native fish to the lower ColoradoRiver13 interactions13 of native and non-shy‐native13 fishes 13ndash1413 July13 1999 Las13 Vegas13 Nevada13 Restoring13 natural function within a modified riverine environment thelower Colorado River13 8ndash913 July13 1998 U S Fish and13 Wildlife13 Service Southwestern13 Region Albuquerque New Mexico Pages 167-shy‐177

Bertalanffy L Von 1957 Quantitative laws in metabolism13 and growth13 Q Rev Biology 32217 ndash 231

Bingham T B Scheer and C McAda 2003 Propagation facilities in Grand Valley (24 RoadHatchery Horsethief13 Ponds and13 grow-shy‐out ponds) for captive13 rearing13 ofendangered13 fishes for the13 upper13 Colorado13 River basin13 Colorado River RecoveryProgram FY2003 annual project report13 US Fish and13 Wildlife13 Service GrandJunction13 4pp

Birchell G J and K Christopherson 2004 Survival growth and recruitment of larval andjuvenile razorback13 sucker (Xyrauchen texanus) introduced13 into13 floodplain13 depressions13 of the13 Green River Utah13 Final report13 Upper13 Colorado13 RiverEndangered Fish Recovery Program13 Project No C-shy‐6RZ Publication Number 04-shy‐1513 Utah13 Division of Wildlife13 Resources Salt Lake13 City13 Utah13 67 pages

Brannon E L 1993 The perpetual oversight of hatchery programs Fishery Research 1819-shy‐27

Brett J R 1979 Environmental Factors and growth pages 599-shy‐67513 InW S Hoar13 D13 J13 Randall and J R Brett (eds) Fish Physiology Volume 8 Bioenergetics and GrowthAcademic Press New York

Brooks J E 1986 Annual reintroduction and monitoring report for razorback suckerXyrauchen texanus in the Gila River Basin Arizona 1985 US Fish and WildlifeService13 Offices of Endangered13 Species and Fishery13 Resources Albuquerque 23 pp

51

13

Brunson13 R E and K D13 Christopherson13 200513 Larval13 razorback13 sucker and bonytailsurvival and13 growth13 in the13 presence13 of nonnative13 fish in the13 Baeser13 floodplainwetland of the middle Green River Final report prepared for Upper13 Colorado RiverBasin Endangered Fish Recovery Program Project No C-shy‐6-shy‐rz-shy‐bt Publication13 No 05-shy‐26 Utah13 Division of Wildlife13 Resources13 Vernal13 32 pp

Bulkley R V and R Pimentel 1983 Temperature preference and avoidance by adultrazorback suckers Transactions of the American Fisheries Society 112601-shy‐607

Burke13 T13 199513 Rearing13 wild razorback13 sucker larvae in13 lake-shy‐side13 backwaters13 LakeMohave ArizonaNevada Proceedings of the Desert Fishes Council 2635

Busacker G P I R Adelman and E M Goolish13 199013 Growth13 Pages 363 ndash 387 in C BSchreck and p B Moyle editors Methods for fish biology American FisheriesSociety Bethesda Maryland

Castro V B Grisdale-shy‐Helland S J Helland T Kristensen S M Jorgensen J Helgrud13 GClaireaux A P Farrell A Krasnov and H Takle 2011 Aerobic training stimulatesgrowth and promotes disease resistance in Atlantic salmon (Salmo salar)Comparative Biochemistry and Physiology -shy‐ Part A Molecular amp IntegrativePhysiology13 160(2) 278-shy‐290

Czapla T E 2002 Facilities plan for the production of endangered fishes to meet statestocking13 plans13 as13 part of the13 Upper13 Colorado13 River Endangered13 Fish RecoveryProgram Upper Colorado River Basin Recovery Implementation Program US Fishand Wildlife Service13 Denver13 9 pp

Davidson W 1997 The effects13 of exercise13 training on teleost fish a review of recentliterature Comput Biochem Physiol 117A67ndash75

Figiel Jr C R 2005 Annual report fiscal year 2004 Willow Beach National13 Fish HatcheryUS Fish and Wildlife13 Service Willow Beach 17 pp

Figiel Jr C R M E Ulibarri G Carmichael J Seals and J N Hanson 2005 Intensive13 fish13 culture of warmwater native fishes at a coldwater fish hatchery Pages 164-shy‐16613 inProceedings of two symposia restoring native fish to the lower Colorado13 River13 interaction13 of native13 and13 non-shy‐native13 fishes July13 13-shy‐1413 1999 Las Vegas Nevada USFish and Wildlife Service Southwest Region Albuquerque New Mexico

Gerking13 S D 1978 Ecology of freshwater fish13 production13 Halstead Press13 New13 York

Gustafson W and Q Bradwisch 2000 Wahweap operation and maintenance -shy‐-shy‐ UtahColorado River Recovery Program FY 2000 annual project report Project No 29cUtah13 Division of Wildlife13 Resources Page AZ 3pp

52

13

Hamman R L 1985 Induced spawning of hatchery-shy‐reared13 razorback sucker ProgressivFish Culturist 47(3) 187-shy‐189

Hanson J N 1996 Annual report fiscal year 1996 Willow Beach National Fish HatcheryUS Fish and Wildlife Service13 Willow Beach 9pp

Irving D S Seversen and M Montagne 2004 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2004 annual project13 report Report No 29b US Fish and13 Wildlife13 Service Vernal 3pp

Jorgensen E H and13 M Jobling 1994 Feeding and13 growth13 of exercised13 and13 unexercised13 juvenile Atlantic salmon in freshwater and performance after transfer to seawaterAquaculture International 2 154-shy‐164

Kaeding L R and D B Osmundson 198913 Colorado13 Squawfish13 and13 razorback sucker grow-shy‐out pond studies as part of conservation measures for the green mountain andRuedi reservoir water sales Final report for agreement number 6-shy‐AA-shy‐60-shy‐00150

Koebele13 B P13 198513 Growth and the size hierarchy effect an experimental assessment ofthree proposed mechanisms activity differences disproportional food acquisition13 pysiological stress Environmental Biology of Fishes 12 181-shy‐188

Kretschmann A E and L L Leslie 2006 Razorback sucker (Xyrauchen texanus) status13 reproduction and recruitment in Senator Wash Reservoir CA Final Report13 to USBurea of Reclamation Cooperative Agreement No 00-shy‐FG-shy‐34-shy‐ 0009 p 32 ArizonaGame and Fish Department Phoenix

Marsh13 P13 C13 1987a13 Digestive tract13 contents13 of adult razorback suckers13 in Lake13 MohaveArizona-shy‐Nevada Transactions of the American Fisheries Society 116117-shy‐119

Marsh P C 1987b Native fishes at Buenos Aires National Wildlife Refuge and ArizonaState University Research Park Arizona opportunities for management researchand public13 education13 on13 endangered species13 Proceedings of the Desert13 FishesCouncil 1967-shy‐78

Marsh P C 1994 Rearing native Colorado River fishes in golf course ponds Arizona StateUniversity Tempe 22 + pages

Marsh13 P13 C13 200013 Fish population13 status and evaluation13 in13 the Cibola13 High Levee PondFinal report agreement number 99-shy‐FG-shy‐30-shy‐00051 US Bureau of ReclamationBoulder City13 Nevada13 20 pages

Marsh P C and C A Pacey 1998 Growth of wild adult razorback suckers13 in Lake13 Mohave13 Arizona-shy‐Nevada13 Final report13 US Bureau of Reclamation Boulder City Nevada 25pages + appendices

53

13

Marsh P C B R Kesner and C A Pacey 2005 Repatriation as s management strategy13 to13 conserve a critically13 imperiled fish species North American Journal of FisheriesManagement 25 547-shy‐556

Marsh P C and C A Pacey 2005 Immiscibility of native and non-shy‐native13 fishes Pages 59-shy‐63 inMJ13 Brouder13 CL13 Springer13 and CS13 Leon13 editors13 Proceedings of two13 symposia Restoring native fish to the lower Colorado River interactions of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 NV and13 Restoring natural13 function within a modified riverine environment the lower Colorado River13 July13 8-shy‐913 1998 Las Vegas NV US Fish and13 Wildlife13 Service Southwest Region AlbuquerqueNew Mexico

Marsh13 P13 C13 and J13 E Brooks13 198913 Predation13 by ictalurid catfishes as a deterrent13 toreestablishment of hatchery-shy‐reared13 razorback sucker The Southwestern Naturalist34188-shy‐195

Matthews R A 2005 Ichthyopthirus multifiliis Fouquet and Ichthyopthirosis infreshwater13 teleosts13 Pages13 159-shy‐218 in Advances in Parasitology volume 59 J RBaker R Muller D Rollinson (eds) Academic Press

McCarthy13 M S and W L Minckley 1987 Age estimation for razorback sucker (PiscesCatostomidae) from13 Lake Mohave Arizona and Nevada Journal of the Arizona-shy‐Nevada Academy of Science 2187-shy‐97

Minckley13 W L13 198313 Status of the razorback13 sucker13 Xyrauchen texanus (Abbot)13 in13 thelower Colorado River basin13 The Southwestern13 Naturalist13 28(2) 165-shy‐187

Minckley13 W L13 199113 Native fished of the Grand Canyon13 region an obituary13 Pages 124-shy‐177 in Colorado River ecology and dam13 management National Academy PressWashington13 DC

Minckley13 C13 O and M LaBarbara13 199913 Report13 on13 native fish grow-shy‐out facilities13 at Cibolaand Imperial National Wildlife Refuges 1993-shy‐199513 US Fish and13 Wildlife Service13 Parker Fishery Resources Office Parker Arizona

Modde13 T13 199613 Juvenile razorback sucker (Xyrauchen texanus) in a managed wetlandadjacent13 to the Green13 River13 Great13 Basin13 Naturalist13 56375-shy‐376

Modde T KP Burnham and E J Wick 1996 Population status of the razorback sucker13 inthe middle Green River (USA) Conservation13 biology 10 110-shy‐119

Modde13 T13 and G13 B Haines13 200513 Survival13 and growth of stocked razorback13 sucker andbonytail in multiple floodplain wetlands of the middle Green River under resetconditions13 Final report prepared for Upper Colorado13 River13 Basin RecoveryImplimentation Program US Fish and Wildlife Service Vernal 66 pp

54

13

Modde T Z H Bowen and D C Kitcheyan 2005 Spatial and temporal use of a spawning13 site in the middle Green River by wild hatchery-shy‐reared13 razorback suckers13 Transactions of the American Fisheries Society 134937-shy‐944

Mueller13 G13 199213 The native fish work13 group13 -shy‐ a multiagency endeavor to improve thestatus of the razorback sucker in Lake Mohave AZ-shy‐NV13 Proceedings of the DesertFishes Council 2369

Mueller G 1995 A program13 for maintaining the razorback sucker in Lake MohaveAmerican Fisheries Society Symposium 15127-shy‐135

Mueller13 G13 200613 Ecology of the bonytail13 and razorback13 sucker and the role of offchannelhabitats13 in their13 recovery Scientific13 investigations13 report 2006-shy‐5065 US GeologicalSurvey13 Denver

Mueller G and E Wick 1998 Testing of golf course ponds at Page Arizona for suitability13 as grow-shy‐out facility for razorback sucker using surplus fish from13 Ouray NationalFish Hatchery National Park Service US Fish and13 Wildlife13 Service and UtahDivision of Wildlife13 Resources 28 pages

Mueller13 G13 and T13 Burke13 200513 Survival13 of young13 razorback13 sucker (Xyrauchen texanus) inrelation to13 stocking rates13 (fishha)13 and13 in the presence13 or absence13 of predatorcommunities in Lake Mohave Arizona-shy‐Nevada13 Pages13 155-shy‐16313 in Proceedings of two13 symposia restoring native fish to the lower Colorado River interaction13 of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 Nevada US Fish and Wildlife13 Service Southwest Region Albuquerque New Mexico

Mueller13 G13 J13 Carpenter13 and P13 C13 Marsh13 200413 Cibola13 High Levee Pond annual report 2004US Geological Survey Fort Collins13 Science Center13 Colorado13 and Arizona StateUniversity Tempe 23 pages

Nesler T P K Christopherson J M Hudson C W McAda F Pfeifer and T E Czapla 2003An integrated stocking plan for razorback sucker bonytail and Colorado13 pikeminnow for the Upper Colorado River Endangered Fish Recovery ProgramAddendum13 to State Stocking Plans Upper Colorado River Basin Recovery13 Implementation Program 12 pp

Papoulias13 D and W13 L Minckley13 1992 Effects13 of foo availability13 on survival and growth13 of larval razorback suckers13 in ponds Transactions of the American Fisheries Society121340-shy‐355

Paukert13 C P D L Ward13 P J Sponholtz13 and K13 D Hilwig13 Effects13 of repeated hoopnetting13 on bonytail chub13 Journal of Freshwater13 Ecology13 20(4) 649-shy‐653

Pfeifer F M13 C Baker13 and M13 Montagne13 199913 Propagation13 facilities13 in the13 Grand Valley13 (24 Road13 Hatchery13 Horsethief13 Ponds and13 grow-shy‐out ponds) for captive rearing of

55

13

endangered13 fishes for the13 Upper Colorado13 River Basin13 Colorado13 River Recovery13 Program FY 99 annual project report Project No 29a13 US Fish and Wildlife Service13 Grand13 Junction13 5pp

Pfeifer F S Seversen and M Montagne 2003 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2003 annual reportProject No 29b13 US Fish and Wildlife13 Service Vernal13 4pp

Rabago-shy‐Castro J L Sanchez13 J G Perez-shy‐Castaneda R and13 Gonzalez-shy‐Gonzlez A 2006Effects of the prophylactic use of Romet-shy‐3013 and13 copper13 sulfate13 on growth13 condition13 and feeding13 indicies in13 channel13 catfish (Ictalurus punctatus) Aquaculture 253 343-shy‐349

Reinitz GL L E Orme and F N Hitzel 1979 Variations of body compositio and growth13 among strains of rainbow trout Transactions of the American Fisheries Society 108204-shy‐207

Ruppert13 J13 B P B Holden13 and P D Abate 1999 Age estimation and growth of razorbacksucker13 Xyrauchen texanus in Lake13 Mead Nevada Proceedings13 of the Desert FishesCouncil 3040

Schnoor K D and J Logan 2002 Operation and maintenance of JW Mumma nativeaquatic13 species restoration facility Colorado Colorado River Recovery Program FY2002 annual project report13 Project No 29d Colorado13 Division of Wildlife Alamosa3pp

Salisbury13 L13 1998 Factors13 affecting razorback13 sucker growth13 in Lake13 Mohave backwaters13 MS Thesis13 Unviersity13 of Nevada13 Las13 Vegas

Schooley J13 D13 and P C13 Marsh13 2007 Stocking of endangerdd13 razorback13 suckers13 in thelower Colorado River Basin13 over three decades 1974-shy‐2004 North American Journalof Fisheries Management 27 43-shy‐51

Severson S H H M Tyus and G B Haines 1992 An evaluation of feeds for raisingrazorback sucker Xyrauchen texanus Journal of Applied Aquaculture 155-shy‐65

Toney D P 1974 Observations13 on the13 propagation13 and13 rearing13 of two13 endangered species13 in a hatchery environment Proceedings of the Annual Conference of the Western13 Association of State Game and Fish Commissions 54 252-shy‐259

Tyus H M13 1998 Razorback sucker13 (Xyrauchen texanus) recovery plan13 University13 ofColorado Center for Limnology Boulder13 76 pages

Tyus H M13 and13 S H Severson 1990 Growth13 and13 survival of larval razorback suckers fedfive formulated diets The Progressive Fish Culturist 52197-shy‐200

56

13

Ulibarri M E 2003 Annual report fiscal year 2001 Dexter National Fish Hatchery13 andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 26 pages

Ulibarri M E 2003 Annual report fiscal year 2002 Dexter National Fish Hatchery andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 59 pages

USBR 2006 Lower13 Colorado13 River Multi-shy‐Species Conservation Program final fishaugmentation plan Boulder City 19 pp

USFWS 2002 Razorback sucker (Xyraouchen texanus) recovery goals Amendment andsupplement to the Razorback Sucker Recovery Plan13 US Fish and Wildlife Service13 Region 6 Denver13 Colorado

USFWS 1999 Annual report 1999 Ouray National Fish Hatchery Vernal 25pp

USFWS 2004 Management plan for the big-shy‐river13 fishes of the13 lower13 Colorado13 river basinamendment and supplement to the bonytail humpback chub Coloradopikeminnow and razorback sucker recovery plans

USFWS13 2005 Station13 profile13 of the13 Dexter13 National Fish Hatchery13 and Technology CenterUS Fish and Wildlife13 Service Dexter

Valdez R A P G Mangan R Smith and B Nilson 1982 Upper Colorado River fisheriesinvestigations13 inW H Miller J J Valentine D L Archer H M Tyus R A Valdezand L13 Kaeding13 editors13 Colorado River Fishery13 Project13 Part 2 Field13 investigations13 US Bureau of Reclamation Salt Lake City Utah

WBNFH 2004 Culture methods of the endangered razorback sucker Xyrauchen texanusUS Fish and Wildlife13 Service Willow Beach National Fish Hatchery13 8 pp

Ward D 2008 Effects of disease treatments on growth of razorback sucker ReportSubmitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 Inpartial fulfillment of work task C10 agreement number 06FG30039

Ward13 D13 M Childs and W Persons 2007 Factors13 affecting13 growth13 of razorback sucker13 (Xyrauchen texanus) in captivity Literature review and knowledge assessmentReport Submitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 In partial fulfillment of work task C10 agreement number 06FG30039

57

Appendices

Appendix 1 Survey Questions Survey of Razorback Sucker Culture in the

Southwestern United States

The enclosed survey is being distributed by the Arizona Game and Fish Department to razorback sucker culture facilities throughout

the Southwestern United States The purpose of this survey is to consolidate information regarding culture of this species so that

appropriate facility improvements can be considered for Bubbling Ponds Hatchery in Arizona Specifically we wish to increase

growth rate and production efficiency at the hatchery Information gathered in this survey will be summarized in a final report to US

Bureau of Reclamation in Boulder City NV and disseminated to all facilities that participate in the survey A workshop to discuss

the findings of this study as well as to share general information concerning razorback sucker culture will be organized by the

Arizona Game and Fish Department at the conclusion of this study and all participants will be invited

Thank you for taking the time to fill out this survey Please contact Mike Childs if you have questions or would like to discuss the

survey

Mike Childs

mchildssedonanet

(928) 639-1346

(928) 634-1279

Facility_____________________________________ Date___________________

Contact Phone _____________________________

ContactPerson_______________________________

Contact Email _______________________________

1 Water quality ranges at this culture facility

Season

Spring (Mar-May) Summer (Jun-Aug) Fall (Sept-Nov) Winter (Dec-Feb)

Temperature (C)

PH

DO (mgL)

PO4 (mgL)

TDS (mgL)

Hardness (mgL)

CaCO3

Pathogens

37

13

Willow Beach National Fish Hatchery13

Willow13 Beach National13 Fish Hatchery receives wild-shy‐caught larvae from13 Lake

Mohave Larvae are treated for diseases with formalin and malachite green and placed in

45 ten-shy‐gallon13 flow-shy‐through aquaria13 Recirculated13 solar heated water13 22-shy‐25deg C is used to13

allow production of warm13 water fish at this traditionally cold water facility (Figiel 2003

Figiel et al 2005) Fish are fed brine shrimp nauplii to satiation every hour and after 14

days small amounts of specialized larval fish diet (Encapsulon13 Cyclopeeze13 spirulina13 and

artificial plankton) are introduced After 30-shy‐6013 days13 fish are13 transferred13 to13 six13 32-shy‐gallon13

fiberglass troughs at densities of 1000 to 1500 fish per tank and then a month later moved

outside13 to13 eight recirculating13 raceways that use a combination of well water and solar-shy‐

heated water to maintain temperatures of 22 ndash 25deg C during the summer months

When13 in13 the outside raceways13 fish are fed the razorback13 diet13 using13 belt13 feeders and

fed by13 hand13 at 10 -shy‐ 70 body13 weight per13 day Feed amount is adjusted based on sample

counts according to a feed conversion program13 developed for razorback suckers by Willow

Beach Hatchery personnel This program13 uses length and number-shy‐per-shy‐pound generated

from13 several years of razorback growth data (Figure13 1) Fish are13 sorted13 opportunistically13

and are not handled during the summer months when water temperatures are above 20degC

In 2004 the target size for stocking was 325 mm TL or greater (WBNFH 2004) with a

target13 of producing13 6000 fish per year Reaching this13 target size usually13 takes13 two13 growing13

seasons13 The biggest difficulty13 in rearing13 razorback suckers13 at Willow Beach13 National Fish

Hatchery13 is insufficient space13 to13 grow fish to13 increased13 target sizes (400-shy‐500 mm TL)

Uvalde13 National Fish Hatchery13

Uvalde13 National Fish Hatchery13 in Texas13 receives 35000 ndash 60000 razorback sucker13

fry annually in MarchApril from13 Dexter National Fish Hatchery The fry are acclimated in

bags submerged in the pond for a minimum13 of one hour and released into13 a 1 acre13 fertilized13

pond where they are reared for the remainder of the summer Fingerlings are fed a starter

razorback diet when they reach approximately 50 mm TL In AprilMay the previous year

class of razorbacks are captured from13 their over-shy‐wintering pond enumerated graded and

split into13 one-shy‐acre grow-shy‐out ponds Approximately 4000 ndash 5000 fish will be13 placed13 in each13

one acre pond for summer grow-shy‐out Fish are reared for approximately 150 days (May ndash

17

13

Oct) and fed the Bozeman razorback diet two times a day five days a week at 15 ndash 30

body weight per day based on average water temperature

Figure 1 Relationship between length and number of fish per pound

In general13 juvenile razorback13 suckers (received as fry13 during13 the previous spring)13

reach the target size of 300 mm TL in approximately 6 months In 20062007 Uvalde

produced 6000 razorback suckers 300 mm TL for introduction into the San Juan River

Starting13 in 2008 Uvalde NFH will be producing13 and distributing13 12000-shy‐ 300 mm TL

razorbacks for stocking into the San Juan River Predation from13 migrating cormorants has

occurred but timing of harvest and over wintering protection methods such as covering

ponds with netting or placing fish indoors helps to minimize losses during the cormorant

migration (November to March) Uvalde has experienced razorback mortalities because of

bacterial problems but these are usually resolved through the use of oxytetracyline

medicated feed

Overview13 of Differences in Culture Methods

Several differences were noted when conducting surveys at each of the five main

production facilities for razorback sucker (See Appendix 3) These differences include

different stocking13 and13 rearing13 densities13 (Table13 4-shy‐5) various feeding regimes and type of

18

13

lt=amp

feeds (Table 7) as well as differences in grading or sorting practices Some of these

differences are13 related13 to13 whether13 or not razorback suckers13 are13 being13 reared13 in extensive-shy‐

culture13 facilities13 (ponds) or intensive-shy‐culture13 settings13 (raceways13 o tanks)13 Some13 practices13

are unique to a single facility13 or a couple of facilities (Table 6)13 Managers at each facility13

were asked to identify the biggest13 difficulty or constraint13 that13 they experience when13

growing-shy‐out juvenile13 razorback suckers13 at their13 respective13 location13 Space constraints13

water quality and disease problems were the main factors limiting production of razorback

suckers13 at these13 facilities13 (Table13 8) Calculated or reported growth rates from13 the literature

vary widely (Table 9) and range from13 02 to 18 mmday These growth rates indicate that

juvenile razorback suckers have a very high growth potential under optimal rearing

conditions13

Table13 4 Stocking13 densities13 for larvae13 and13 fry in ponds

$amp( )(+amp-( 01-2(3(4amp56( 4amp56(+amp-( 01-2782-( $amp () + --amp +amp0amp)+amp 12-3amp ( )+amp0amp+amp --amp +amp0amp)+amp 42556789amp8 ( +amp0ampgt+amp 3amp +amp0amp+amp A-BC-Damp (E + 3amp )+ F-6ltamp ) G+ 3amp G+

Table13 5 Rearing13 densities13 at intensive13 culture13 facilities13

$amp( )amp+(($-( $0( 12(3$+( 40((amp05( 67((amp05( 8$9(407$( $amp amp())amp++-$amp 0 1 0amp2amp1amp 3amp2amp4 0544

6amp())amp++-$amp 610 021 4amp2amp47amp 3amp2amp77amp 058 9$amplt+)amp 4amp())amp++-$amp 00 1 7amp2amp77amp 851amp2amp0amp 05

6amp())amp++-$amp 610 77amp2amp1amp 0amp2amp1amp 053

19

13

Table13 6 Rearing13 practices13 that are13 unique to13 specific rearing13 facilities13 $$amp( )$+-(amp$-(0(1-amp2034( $amp()amp+( -0$(12(33+(amp(amp134$53+(amp$amp3+(6amp+(

723(843(1$8(422(6amp+(42amp(4(423(19$43( 343( lt34$53(6amp+(6(4($03(amp4+94amp(842($1$1(63$$34(amp+(63626243( =amp+(gtamp94ampA( B3(1(1$+53+C3+(amp+(1$43(1(3D0$(1(amp443(amp+(amp443( 734231(amp( B3(1(193(44(1(34amp(amp(+49E(6amp+( -E3(F3+( G3amp(1(12(amp(H3(13$(4ampE(C(IJK($$amp( A( L43(+A3(4(6303amp4(63+4ampM(66$3D3amp4$(34amp(amp(6amp+(C((4amp3( L$$8(392(

B0$+3(

N43D(13+(4($0$(12M(amp+(639$53+($0$(12(+34( G3amp(12(amp(399$4amp(4+(938A(842($(2343+(843( N443D643+(3amp(12(amp(amp34(63amp(amp(423(O$+(G03( )amp+(3(134$53+(6(4(39364(1(1A(4(44(423D(amp((D3(amp4$(+34(

Table13 7 Types of feed used at razorback sucker13 hatcheries13 $amp ()amp+-amp0- $$)1amp23 45-amp)-$5)1amp23 $amp()amp+( -amp$amp+(amp+( -amp012$3+(amp+4(amp5215$(0+( 65ampamp7(85209(+2($1(87((15315lt=(+2(

+amp+amp(amp(55$5$2gt( 21( Aamp+(amp+( )amp+(012$3+(B29(5$05$95($$2(5amp+(

199524(amp5215$(0+( 65ampamp7(85209(+2($1(87(15315lt=(+2(amplt( 29gt(51($51(amp9(2(25=(C(DD(0+(

E15amp+(Famplt2amp( G1$5(lt1lt$51(25amp=( HIJKH(Dlt1amp(15315lt=(+2(I(C2(CH(+5gt( )11$gt($511(02+(15315lt=(+2(

$1(87(15315lt=(+2(D5$$(3(lt5$$gt(02+(gt( 6lt=(511B(

L15gt( G1$5(lt1lt$51(25amp=(Aamp+( amp+(

HIJKH(Dlt1amp(15315lt=(+2(I(C2(CH(+5gt( )11$gt($511(02+(15315lt=(+2(

$1(87(15315lt=(+2($1(87($B(amp=amp( 5$Damp(+2(

M$$B(5lt9(-5$+( NO515(G1$5(219( L2+1(15ltB5gt(Aamp+(5amp+( amp$amp+(amp+(

1amp(91D(amp5$(Pamplt5$amp4( 8gtlt$34(1$amp54(5amp+(5120lt5$( $5amp=2amp()amp+(012$3+(B29(5$05$95( $$2(5amp+(19952Q(amp12152( 1+lt2amp(

$1(87(15315lt=(+2($1(87(15315lt=(+2( $1(87(15315lt=(+2(

Table 8 Factors limiting production at major razorback sucker facilities

$amp( )amp+(-0+1((2$(0amp1ampamp(-34amp( $amp()amp+( -(01$2(34+(546(amp(0amp(01amp(541(13( -741( 803(3amp41amp4(9((+ltlt1amp4(03(amp(44amp(2=(4(

+ltlt3$4(4(2amp4amp(014(1gt13=(43=( 1amp+(amp34amp( 803(3amp41amp4(1$4+(4(541(A$4B(amp+(+$C+(

7Bamp($244amp(lt(1313$4amp(B42( D1B( E41(A$4B(01$2(3+(B(66(1amp(amp+(2ampamp(

Eamp41(420141(464(1A1($$(lt6(4((2C+(amp+1( 803(3amp41amp4(1$4+(4(541(A$4B(amp+(+$C+(7Bamp(

E$$5(36( 803(3amp41amp4F(15amp(lt6(4(amp31amp$B($11(gt( 1$4(amp(ampltlt3amp4(03(amp(44amp(lt1(amp5(lt6(

GC$+( 8221(420(3amp(4(6691A1amp(051((4(410$(+(4( 661(1amp+541(020amp(4(=0(0amp+(3$F(

20

13

$amp(

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lt(6(

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-(=22

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Table9Reportedandcalculatedgrowthratesfromtheliterature

Calculatedgrow

thratesbasedon

informationprovidedinliterature

aApproximationsofmaximum

grow

thpotential(basedon

average13 maximum

sizesiffishreportedatharvest

21

13

General Information on Factors that Affect Fish Growth

Growth in fish is extremely variable and is impacted by many different

physiological and environmental factors Growth rates are known to change with size and

age sex season activity level density amount13 of living space quality and quantity of food

genetics and temperature (Brett 1979) Growth experiments conducted at different times

of year can result in growth rates that are not comparable As fish become larger their

physiological13 potential to grow decreases making determination of growth rate dependent

on the size of the starting fish and the length of the experiment (Busacker et al 1990)

Genetic factors also have great potential to influence growth rate Some species have

strains13 and13 races13 that display vastly different growth potentials (Reinitz et al 1979) All of

these factors combine to make assessment of the individual factors controlling fish growth

difficult13

Water temperature is probably the most important variable affecting growth rate13

All of the basic functions that affect growth such as feeding digestion and metabolism are

temperature-shy‐dependent13 Growth13 is inseparably13 tied13 to13 bioenergetics13 and13 therefore13 also13

tightly tied to temperature When temperatures are below optimum daily temperature

fluctuations can stimulate growth Photoperiod is also commonly linked to water

temperature and can influence growth rates in fish (reviewed in Brett 1979)

Fish density13 is known to13 affect growth13 and13 can alter13 growth13 rates13 in several ways13

Fish that exhibit strong territorial behaviors13 or natural schooling tendencies13 will

experience reduced growth if densities are too high or too low (Brett 1979) Dominance

hierarchies where some fish feed more aggressively than others can also lead to high

variability13 in growth13 rates13 (Koebele13 1985) Crowded13 conditions13 also13 cause physical

interference13 between13 fish and13 poor water13 quality13 which13 reduces13 growth13 (Busacker13 et al13

1990) The effects of fish numbers space and feeding opportunity are frequently correlated13

and often13 difficult13 to distinguish (Brett13 1979)13

It is impossible to study the effects of environmental factors on growth without also

evaluating feed rations (Brett 1979) Amount of food quality of the diet particle size

number of feedings per day and time of feeding have all been shown to affect growth

(Busacker et al 1990) In controlled laboratory studies food is usually fed ad libitum13

22

13

(constantly available) and other variables are altered to assess impacts of environmental

factors13 on growth13 These studies13 are13 usually13 conducted13 in tanks13 or raceways13 because13

researchers must verify that food is constantly available to the fish which is difficult to do

in large pond environments where the fish and the bottom13 are often not visible (Busacker13

et al13 1990)

Specific Information13 o Razorback13 Sucker13 Growth

Variable13 growth

Growth in razorback suckers is naturally highly variable and may be a function of

their evolutionary history (USFWS13 2002)13 Minckley (1983) speculated that13 wide size

variation in a single cohort of razorback suckers may be adaptive with fast-shy‐growing13 fish

that13 reproduce at a young13 age surviving13 better in13 high discharge years and slow-shy‐growing13

smaller fish surviving better during drought periods This highly variable growth rate

makes rearing razorback suckers in a production setting difficult because fish from13 a single

cohort do not reach the target stocking size simultaneously One of the major tasks for

aquaculture is to maximize both individual growth and total production13 (Gerking13 1978)13

This becomes more difficult when the species being cultured exhibits highly variable

growth13 rates13 because of genetic influences as is the case with razorback13 suckers13

Razorback13 sucker growth13 is typically very13 rapid13 during13 the first13 year of life13 and then13

declines with age First year growth can be as low as 50 mm and as high as 350 mm (Valdez

et al13 1982 Minckley13 1983 Mueller13 1995) Razorback sucker13 grow rapidly13 for

approximately the first five or six years of life and then growth slows13 (McCarthy13 and13

Minckely 198713 Tyus 199813 Minckley et13 al 1991)13 Growth of older individuals in13 extant13 wild

populations is very13 low (Minckley 198313 Tyus 198813 Modde13 et al 1996)13 Wild growth13 rates

for mature adult fish in Lake Mohave based on PIT tag recaptures were often too small to

be accurately measured for both males and females over the time period of 1987-shy‐199713

(Marsh and Pacey 1998) This information suggest it will take substantially longer to rear

fish to13 increasingly13 larger13 stocking13 sizes (40013 ndash 500 mm TL) than it did to reach the target

size of 300 mm TL

Growth in ponds

23

13

One of the main strategies for maintaining genetic refugia and self-shy‐sustaining13

populations of razorback13 sucker in the lower Colorado13 River basin13 is to rear razorback13

sucker13 larvae13 in production13 ponds until they13 are13 a suitable13 size for stocking13 (USFWS13 2004)

Pond culture has proven useful to promote rapid growth of juvenile razorback suckers

(Kaeding and Osmundson 1989) Marsh (1994) reported that growth rates of razorback

suckers13 reared13 in golf-shy‐course13 ponds exceeded13 the13 best growth13 rates13 obtained13 under

intensive13 culture13 conditions13 at federal hatcheries13 especially13 during the13 first several years13

of life Growth rates in these semi-shy‐natural ponds are also comparable to estimated growth

rates13 of juvenile13 wild13 fish (McCarthy13 and13 Minckley13 1987) Modde13 and13 Haines13 (2005)

reported13 the13 greatest growth13 rates13 in the13 largest and13 deepest floodplains13 with13 the13 greatest

amount of submergent vegetation but excellent growth and survival of fish in a grow-shy‐out

pond is of little value if there is not an efficient way to collect the fish from13 the pond

(Kaeding and Osmundson 1989)

Temperature13

Bulkley and Pimentel (1983) used shuttle boxes in the laboratory to determine a

temperature preference13 for razorback suckers13 of 23-shy‐24degC13 In13 their13 studies13 razorback

suckers were found to avoid temperatures below 118 degC or above 286 degC Razorback

suckers at Bubbling Ponds Hatchery are more active in the spring and feed better as

photoperiod increases even prior to water temperatures rising (Frank Agygos personal

communication) Table 3 briefly summarizes water temperature data from13 each facility

Detailed seasonal water temperature profiles are not currently available for many

razorback grow-shy‐out sites13

Density13

Extensive studies have been conducted on commercially important species to

evaluate stocking densities and feeding rates that maximize production For these species

controlled experiments under laboratory conditions have established relationships

between temperature density and feed ration on growth (Brett 1979) but this information

is sporadic13 or non-shy‐existent for razorback suckers13 (Bays13 et al13 2005) Fish culturists13 with13

24

13

experience13 rearing13 razorback suckers13 typically13 have13 target stocking13 densities13 that13 they use

(Tables13 4 -shy‐ 5) These stocking densities have largely been determined over time by trial

and error These approximate stocking densities provide a good starting point for more

controlled13 types13 of replicated13 pond studies13

Feed ration

Razorback13 suckers are currently13 being13 fed a wide variety13 of prepared diets (Table 7)

that range from13 a slow-shy‐sinking salmon feed manufactured by Silver Cupreg to a spirulina

and krill-shy‐enhanced catfish feed made by Rangenreg Most locations are feeding 20 ndash 50

body13 weight per13 day13 Methods13 for culture13 of razorback sucker13 larvae13 in intensive13 settings13 at

fish hatcheries are well documented (Figiel 2005) and various larval fish diets have been

evaluated13 (Tyus and13 Severson 1990 Severson et al13 1992) but no standardized13 procedures

are used for feeding13 larval13 fish in13 intensive settings13

Razorback sucker larvae are also effectively reared in pond environments using

natural foods supplemented with larval fish diets and survival is high when no predators

are present13 (Mueller 2006)13 Growth rates for larval13 and early juvenile razorback13 suckers

may increase with pond fertilization Diet and physiological studies on wild razorback

suckers indicate that they feed on plankton as well as benthic organisms during their entire

life (Marsh 1987) Artificially fertilizing ponds may greatly increase production capacity

and growth rates for razorback13 sucker (Papoulias and Minckley13 1992) and warrants

further13 investigation13

Handling stress

Handling stress13 has13 been shown to13 influence growth13 rates13 Paukert13 et al (2005)

found that growth of bonytail chub was reduced by 26when compared with controls

after being13 repeatedly13 captured and handled in13 hoop13 nets13 Handling13 effects are likely13 to be

similar for razorback suckers that are repeatedly13 captured and sorted in13 a hatchery13 setting13

Razorback suckers that are handled at Willow Beach National Fish Hatchery will commonly

not eat for two weeks after handling (John Scott personal communication) This creates a

difficult situation13 for production13 facilities because13 fish13 need to be sorted to ensure13 large13

25

13

aggressive fish do not interfere with growth of smaller individuals but frequent handling

and sorting13 causes stress related reductions in13 growth13

Measuring Growth in Captive Fish

Weight is the traditional measure used to estimate growth or production in

aquaculture settings13 Groups of fish are typically13 weighed and an average individual13 weight13

is computed (Busacker et al 1990) Although this method is often logistically the easiest it

may not be the most informative for species with highly variable growth rates like

razorback suckers especially when target lengths must be reached before fish can be

stocked Weight can also be highly influenced by things like stomach fullness or

development of gonads (Busacker et al 1990) Condition factor or relative weight can also

be used to assess growth of fish but these tools may be more robust predictors of fecundity

than of growth (Anderson and Neuman 1996) For some species sexes need to be

distinguished because males and females may differ in morphology (Anderson and

Neumann 1996) Mueller (2006) analyzed growth rates based on PIT tag recaptures of 86

razorback suckers13 in High13 Levee Pond13 and13 found13 that differences13 in growth13 do not appear13

to occur until fish are over 450 mm TL at which time growth rate in males slows while

females continue to grow at a slightly higher rate This would indicate that sex may not be

an important factor to consider when examining growth rates unless the target grow-shy‐out

size is above 450 mm TL

The best measures of growth are often determined from13 the length and weight of

individuals rather than from13 groups of fish (Anderson and Nuemannn 1996) because

individual growth rates give better estimates of confidence and variance (Busacker et13 al

1990) Length frequency analysis or recapture of previously marked individuals of a known

size is likely to yield the most useful information for razorback sucker growth The success

of any of these methods depends on proper sampling procedures that are representative of

the population as a whole (Busacker et al 1990) Sampling methods that are known to be

size-shy‐biased such as trammel nets (Mueller et al 2004) or cast nets should not be used when

trying to measure growth rates13

26

13

Conclusions

For razorback sucker survival is largely associated with stocking size Additional

focused13 research13 is therefore13 needed to13 identify13 ways13 to13 increase13 growth13 rates13 of captive-shy‐

reared13 razorback sucker Growth13 rate13 in fish is controlled13 by many factors including fish

size and age temperature density and feed ration which can all be highly correlated

Growth of razorback suckers is also inherently variable which makes the task of identifying

the key factors that13 affect13 growth in13 captivity even more difficult The focus at most

razorback rearing facilities13 is production so the13 types13 of data that are13 collected13 are13 often

insufficient for detailed13 evaluations13 of individual rearing13 practices13 on growth13 Surveys of

existing13 razorback sucker13 rearing facilities indicate that culture methods vary widely and

the types of growth data13 that13 are collected are not13 standardized13 Replicated studies with

detailed information on rearing location water temperature initial stocking size stocking

density and the sizes of all fish at harvest are needed in order to compare the effects of

individual rearing practices on growth This type of research will ultimately provide both

time and cost-shy‐savings to production facilities by reducing the amount of time necessary13 for

razorback sucker to reach stocking size improving overall production efficiency

Optimum13 rearing densities for razorback sucker larvae and juveniles remain to be

determined Current stocking densities will be very useful as starting point for more

detailed studies and although optimum13 rearing densities are likely to be site-shy‐specific13

replicated studies on density will provide a valuable reference for hatchery managers

Frequency13 of sorting is another13 area that needs13 further13 research Frequent

handling13 and13 sorting13 can13 cause13 stress-shy‐related13 reductions13 in growth but not sorting can

create dominance hierarchies that further reduce growth rates of subordinate individuals

The effects13 of sorting13 on overall fish growth13 in both13 pond and13 intensive13 culture13

environments warrant further investigation Research techniques for these types of

experiments are well understood and typically utilize a matrix of replicate ponds per

variable (Bays et al 2005) In every case accurate and complete records of sampling

procedures and data collection are needed in order to interpret data and make inferences

about13 growth rates (Busacker et13 al 1990)13

27

13

Additional research is also needed to evaluate long-shy‐term13 survival of stocked fish

reared in ponds compared to fish13 reared13 in intensive13 culture13 facilities13 Exercise13

conditioning13 and predator-shy‐recognition training may also increase survival of stocked fish

and be more economically feasible than rearing fish to increasingly larger sizes prior to

stocking13 The success13 of traditional fish hatchery programs is measured largely by the

number of fish stocked but hatchery programs for endangered species must measure

success in terms of long-shy‐term13 survival and species recovery (Brannon 1993 Anders 1998)

A specific list of research recommendations follows

Specific Research13 Recommendations13

bull Use replicated studies13 to establish optimum stocking13 densities13 for ponds13 and

tanks13 that can be used as13 a starting13 point for site specific refinement

bull Determine if sortinggrading13 improves13 overall growth rates13 in both ponds13 and

intensive culture facilities13

bull Investigate the use of artificial fertilizers13 to improve growth of both juvenile

and adult razorback suckers13 in ponds13

bull Determine if the razorback sucker diet gives13 better growth rates13 than cheaper

catfish or salmon feeds

bull Evaluate growth rates13 and production potential of new intensive culture

methods13 such as13 large circular tanks13

bull Evaluate13 long-shy‐term survival of fish produced from raceways13 and circular tanks13

compared to fish reared in ponds13

bull Evaluate more effective means13 of treating13 fish diseases13

bull Evaluate factors13 other than size that may increase post-shy‐stocking13 survival such

as13 exercise conditioning13 predator recognition training or rearing13 under more

natural settings13

28

13

II The Effect of Disease Treatments on Razorback Sucker

Growth

Section13 SummaryFormalin copper sulfate potassium permanganate and13 salt are all chemicals commonly13 used13 to13 treat13 Ichthyophthirius multifiliis outbreaks in captive razorback sucker (Xyrauchen13 texanus) Weexposed 190 juvenile13 razorback suckers (127 ndash 26 mm TL) to13 5 5-shy‐day treatments with13 each13 chemical to evaluate the effects13 these chemicals13 may have on growth Fish grew an average of23513 mm TL13 during the month13 study period Fish treated with formalin grew on average13 29mm TL (03 mmday) while fish treated with copper had the lowest growth averaging 20 mmTL (021 mmday) No significant differences in13 growth were observed among fish treatedwith any of the chemicals compared to untreated fish (pgt005) Reductions in growth13 as aresult of repeated chemical treatments are not likely the cause of differences in growth ratesamong13 facilities that raise razorback suckers Repeated chemical treatments may13 have otherimpacts to overall13 fitness or long-shy‐term survival but13 these effects were not13 evident13 in our study

29

13

Introduction

Preservation13 of razorback sucker13 (Xyrauchen texanus) currently13 depends on captive13

rearing and stocking programs until permanent solutions to factors that prevent wild13

recruitment are found Low survival of stocked razorback suckers (Brooks 1986 Marsh

and Brooks 198913 Marsh and Pacey13 2005) has caused target13 sizes for stocked fish to

steadily increase in efforts to reduce predation mortality (Marsh et al 2005 Schooley and

Marsh 2007) Rearing fish to larger sizes at hatcheries comes with increased costs and

creates the need to evaluate husbandry and rearing practices that may affect fish growth

Formalin copper sulfate potassium13 permanganate and salt are all chemicals

commonly used at razorback sucker rearing facilities to treat outbreaks of the protozoan

parasite13 Ichthyophthirius multifiliis ldquoIchrdquo is one of the most pathenogenic diseases of

cultured13 freshwater13 fishes (Matthews13 2005) and causes large13 losses in captive13 populations13

of endangered razorback sucker Each of these chemicals used to treat Ich only kill the free-shy‐

swimming life stage of the parasite13 requiring13 repeated doses over several13 days depending13

on water temperature These chemicals treatments are needed to prevent loss as a result

of disease outbreaks but the cumulative effects repeated disease treatments have on

growth13 are13 unknown

Copper13 sulfate13 has13 been shown to13 significantly13 reduce13 growth13 of channel catfish13 in

production13 ponds (Rabago-shy‐Castro13 2006) but it is unknown whether13 razorback suckers13

experience similar reduced growth following copper treatment Quantifying the impacts of

disease treatments on growth will help to interpret the wide differences in growth rates

observed13 at various13 razorback sucker13 production13 facilities13 throughout the13 southwest

(Ward et al 2007) If one chemical is found to have less detrimental impacts on growth

than another then it may be preferred for use as a disease treatment We evaluated growth

rates13 of razorback suckers13 under13 replicated13 and13 controlled13 conditions13 to13 assess13 effects13 of

repeated formalin copper sulfate and potassium permanganate and salt treatments on

growth13

Methods

We captured 190 juvenile razorback suckers from13 ponds at Bubbling Ponds Fish

Hatchery AZ using hoop nets or cast nets All fish were of the same age class and

30

13

averaged 179 mm total length (TL) (range13 = 127 ndash 262 mm TL)13 These fish were13 offspring13

of captive13 razorback sucker13 broodstock held13 at Dexter13 National13 Fish Hatchery13 NM13 (2007

year class) All fish were tagged with passive integrated transponder (PIT) tags and

quarantined for one month prior to the experiment to allow fish to recover from13 tagging

and become accustomed to being held in circular tanks

At the beginning of the study all fish were weighed measured and scanned for

individual tag numbers with 19 randomly selected fish placed into each13 of 10 8-shy‐foot

diameter circular tanks (Figure 2)13 Each13 tank contained13 two13 airstones13 and13 an13 individual

biofilter with a recirculating water pump (31 litersminute) that had been operating for

at least 1 month prior to the experiment to allow bacterial colonies to become

established Two tanks were designated as a control and did not receive any chemical

treatments while the other eight tanks received formalin copper sulfate potassium13

permanganate or salt treatments at two week intervals (two tanks per chemical

treatment) Formalin copper sulfate and potassium13 permanganate were treated at 1 part

per million (ppm) and salt was applied at 30 parts per thousand (ppt) These treatment

rates are commonly used to treat13 razorback13 suckers for ich at Bubbling13 Ponds Fish13

hatchery (Frank Agygos personal communication)

Figure 213 Photo ofexperimental tankswith individualbiofilters and aeration

31

13

Each treatment consisted of a series of doses applied on Wednesday Thursday and

Friday with a 90water change between each dose Biofilters were removed from13 all

tanks and held in a separate holding facility during treatments and then replaced on the

Monday following treatments after a 90water change This schedule allowed fish to be

exposed to chemical treatments for 5 consecutive days without water quality deteriorating

This 5-shy‐day chemical treatment was repeated every two weeks from13 July to October (97

days)13 for a total of 5 5-shy‐day treatments Water temperature in the treatment tanks ranged

from13 13degC (55degF) to 32degC (91degF)

Fish were fed a fixed ration of commercial razorback diet (Silvercup 4mm13 pellet)

once daily13 (2 percent body13 weight per day13 as calculated13 by13 average initial fish weight)13

At the end of the experiment all fish were again weighed measured and scanned for

individual tag numbers Growth of fish in each treatment group was compared using

analysis of variance (ANOVA) Any mortalities13 that occurred during the13 study13 were13

replaced with previously quarantined fish of equivalent size to maintain equal densities in

each13 tank13 but growth13 data was13 only13 recorded for fish which13 survived13 the13 entire13

experiment

Results

Fish at the13 start of the experiment averaged 179 mm TL (Range13 = 127 ndash 262 mm)

with no significant differences in fish length among treatment groups (F(4189) = 00183 p

gt 0999 ANOVA) On average fish grew 235 mm TL (024 mmday) during the 3 month

study13 Fish in tanks13 treated with formalin had the highest growth averaging 29 mm TL (03

mmday) while fish in tanks treated with copper had the lowest growth averaging 20 mm

TL (021 mmday) Fish in the control tanks averaged 213 mm TL in growth (022

mmday) (Figure13 3)13 Formalin-shy‐treated fish grew13 significantly faster than13 any other

treatment group but no13 significant differences in growth13 in length13 or weight were13

observed among fish treated with any of the chemicals compared to untreated (control)

fish (pgt005 ANOVA)

32

13

Figure 313 Average growthof razorback suckersexposed to a series of 5 5-shy‐day chemical treatmentsover a 97-shy‐day13 periodError bars representstandard error

Discussion13

Growth13 rates13 observed13 in our study13 (021 ndash 03 mmday) are low compared to those

reported13 in other13 studies13 of razorback sucker13 growth13 (0213 ndash 18 mmday) (Ward et al

2007) Using recirculating water systems for our study required filters to be removed and

replaced during treatments Stress to fish caused by removing and replacing filters within

the tanks as well as repeated water changes may have led to overall higher stress and

reduced growth rates compared to those reported for unconfined fish Growth in fish is

highly variable and is affected by many different physiological and environmental factors

including fish size density temperature amount of space and food (Brett 1979) We

strived to control each of these factors but other factors may have also influenced growth

in our experimental tanks During mid-shy‐summer water temperatures in the treatment

tanks reached 32degC (91degF) At these warm13 temperatures fish are very susceptible to

bacterial13 infections13 The slightly higher growth exhibited by fish in the formalin and

potassium13 permanganate treatments may have been the result of these two chemicals

33

13

being effective at controlling bacterial infections The differences in growth we measured

among treatment groups were not statistically significant and do not appear13 biologically13

meaningful during the relatively short duration of this study (97 days) although the

cumulative effects of slightly reduced growth could be biologically meaningful over longer

time frames

Reductions in growth13 as a result13 o repeated chemical treatments are not likely the

cause of differences in growth rates among facilities that raise razorback suckers

Repeated chemical treatments may have other impacts to overall fitness or long-shy‐term13

survival but these13 effects13 were13 not evident in our study It is more likely that the parasite

outbreaks themselves are the cause of different growth rates among razorback rearing

facilities rather than the chemical treatments used to treat the parasites We recommend

that hatchery managers continue to use the chemicals that are most effective at controlling

ldquoIchrdquo13 at their individual13 facilities

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower Colorado Rive Multi-shy‐species13

Conservation Plan under Work Task C10 We thank Ty Wolters and Tom13 Burke for their

support of this research and Frank Agygos and Dave Billingsly of the Bubbling Ponds Fish

Hatchery13 for their13 technical assistance13 and13 help with13 collecting13 fish

34

13

III13 Razorback Growth Rates at Bubbling Ponds ndash 2009-shy‐2011

Section13 SummaryExperimental studies at Bubbling Ponds Fish Hatchery AZ have strived to understand

factors that affect razorback sucker growth in captivity and identify ways to improve growthrates and maximize size at release Rather than performing experimental studies that wouldrequire major13 rearrangement (and likely reduced production)13 of hatchery operations our13 studies13 used normal variation in production techniques13 and practices13 to isolate factors13 thatmay modify growth rates

Our initial work identified razorback13 growth rates in13 lined ponds at standard fishdensity as 026 to13 028mmday (789 to 843 mmmonth) No significant differences in growthrate were observed among fish that had been in the pond only during the winter13 periodcompared to fish that had been in the pond the entire year indicating that water temperatures13 at Bubbling Ponds are high enough to allow fish to incorporate feed effectively year-shy‐roundHowever these growth rates are lower than most values reported from the literature fromnatural or semi-shy‐natural pond environments No significant differences in13 growth rate wereobserved13 between large and13 small fish13 within the 150 ndash 29 mm TL13 size range Additional worksuggests13 that razorback suckers13 tagged at over 300 mm TL had reduced growth rates (024mmday 73 mmmonth) as would be expected according to a typical Von13 Bertalanfy growthcurve although growth rates13 were only slightly less13 than the average growth rate for thehatchery (027513 mmday 82513 mmmonth)

Sorting13 to13 separate small fish from large fish after the first year of growth is practicedesigned13 to allow smaller fish to ldquocatch uprdquo to larger fish We found that13 this technique doesappear to13 improve growth rates of smaller fish Growth rates of sorted small razorback suckers(029 mmday 87mmmonth)13 were equal to that13 of larger13 fish (028 mmday 8413 mmmonth)indicating that sorting may have helped to offset their original slower growth trajectory

Bubbling Ponds Fish Hatchery grows razorbacks in 6 long deep ponds lined with heavyplastic 2 long deep13 earthen13 (unlined) ponds and three wide shallow earthen ponds The wideshallow ponds13 have historically produced very large fish at low density but have been found tomaintain much lower fish numbers than deeper ponds We found13 that growth13 rates ofrazorbacks kept at high density (4-shy‐700013 fish)13 in a wide shallow pond grew extremely slowly(024 mmday 726 mmmonth) This growth rate is among the slowest of any fish over theyears of our study and demonstrates that13 though the large ponds may produce large fish at lowdensity13 they are unable to overcome high13 fish13 densities

Finally one of the major factors influencing13 fish13 growth13 in hatcheries is disease onemajor summer-shy‐time disease at13 Bubbling Ponds is the ectoparasite Ich (Ichthiopthirusmultifiliis) To investigate the impact Ich has on razorback growth we eradicated fish from thespring and water conveyance ditch that supplies13 water to the hatchery using Rotenone This13 restoration effort was fairly short-shy‐lived (Ich returned to the hatchery within four months) but

35

13

growth13 rates of fish13 reared for four months without Ich present (031 mmday 92 mmmonth)were significantly higher than the following 8 months of growth for those same fish (022mmday 65 mmmonth) This disease-shy‐free growth rate is in fact faster than any13 otherprevious growth rates observed at the hatchery in our study

We conclude that growth rates at the Bubbling Ponds Fish Hatchery are likely as highas possible given the pond densities required to13 meet production goals and the Ich-shy‐infestedwater13 that feeds the facility Sorting practices are successful in helping as many fish as possiblereach stocking length as fast as possible Unlined ponds may be able to grow large fish at lowdensities but whatever factors allow for that growth13 are not able13 to overcome13 high fish densityThus the large lower ponds at Bubbling Ponds may be better utilized via renovation to13 deepenand line them

Disease is the most important factor limiting growth as may be expected to be the caseat many13 hatcheries While the spring renovation was not13 a complete success13 the dramaticreduction of fish populations in that habitat was enough to dramatically13 reduce13 the13 occurrenceof Ich at the hatchery13 Such open spring13 systems feeding a hatchery are a misfortune that canbe expected to transmit disease so we suggest that renovating the spring again to combat13 IchImproved techniques to divert water from13 the springs and more throuough treatment ofstream-shy‐side vegetation may improve the success of chemical treatment Successful renovationwould likely both improve growth rates and reduce chemical costs associated with treating Ichoutbreaks Even13 if complete renovation13 is impossible or impractical an13 effort to reduceinvasive fish density in the springs13 which act a vector for the parasite(and thereby reduce thelikelihood of13 Ich being transmitted into ponds) may still13 show dramatic improvements

36

13

Introduction

Conservation efforts13 for razorback sucker13 (Xyrauchen texanus)13 currently13 depend on

captive rearing and stocking programs Low survival of stocked razorback suckers (Brooks

1986 Marsh13 and13 Brooks13 1989 Marsh13 and13 Pacey13 2005) has13 caused13 target sizes for stocked13

fish to steadily increase in efforts to reduce predation mortality13 (Marsh13 et al13 2005

Schooley and Marsh 2007) Rearing fish to larger sizes at hatcheries comes with increased

costs and creates the need to evaluate husbandry and rearing practices that may affect fish

growth13 We evaluated growth13 rates13 of individual razorback suckers13 in ponds13 at Bubbling

Ponds Fish Hatchery13 using Passive Integrated13 Transponder (PIT) tags13 to13 obtain13 precise

growth information for individual fish so that valid comparisons of growth rates as related

to rearing practices can be made

Due to the critical nature of the razorback sucker stocking program we did not

design experimental studies that would require major rearrangement and potentially

reduce production of hatchery operations Instead our studies used normal variation in

production techniques and practices to isolate factors that may modify growth rates

Though this methodology dramatically limits replication and may limit our ability to

directly13 attribute13 differences in growth13 rates13 to13 the13 variables13 we13 investigate13 we13 were13 able13

to accomplish research goals without altering hatchery operations or impacting

production

From13 2009 through 2011 we conducted a series of observational13 growth13 studies to

determine growth rates of individual razorbacks at Bubbling Ponds The first set of

experiments included13 identifying13 growth13 rates13 in lined13 and13 unlined13 ponds determining

growth13 rates13 of fish at different13 sizes13 in13 relation13 to sorting13 practices and monitoring

razorback growth rates after removing the source of the ectoparasite13 Ich (Ichthiopthirus

multifiliis) from13 the hatchery water source13

Razorback growth rate in lined ponds

Our first growth study documented individual growth rates at normal density in 11

million gallon lined ponds13 over two13 years13 This is the standard13 grow-shy‐out process for

razorbacks13 at Bubbling Ponds We monitored growth of fish for a variety13 of sizes and13 the13

37

13

amount of time in a pond during the growing season These13 data give a snapshot of growth13

rates13 at the13 facility13 and13 provide13 the basis for comparisons throughout our study

Growth rate13 in an unlined pond

In addition13 to 6 ponds lined with heavy plastic13 sheeting13 Bubbling Ponds Fish13

Hatchery maintains two narrow and deep (same dimensions as lined ponds13 Figure13 4)13 and13

three large13 shallow unlined ponds These earthen13 ponds typically have vegetation and

associated aquatic invertebrates that may better simulate natural environments by

providing cover and improved food diversity or quality Therefore these unlined ponds

may be expected to produce higher growth rates and potentially improved survival that is

more similar to growth rates observed in more natural grow-shy‐out facilities13 Historically13 the13

large13 shallow13 ponds have produced very large fish when13 utilized at low13 fish density13 The

narrow13 deep earthen13 ponds are13 used to grow13 fry13 at high density in their first13 year of life

The major downside to unlined ponds is the difficulty in harvesting fish where a lined

pond might take 8-shy‐1013 people13 a half13 day13 to13 harvest13 lined13 ponds13 require13 intensive13 weeding13

to allow seines to be pulled and therefore require many more personnel-shy‐hours13 In addition13

to harvest challenges the shallow earthen ponds tend to suffer from13 dissolved oxygen

crashes during the summer Unlined ponds also may maintain higher13 populations13 of non-shy‐

target species such as bluegill sunfish mosquito fish and bullfrog tadpoles We measured

growth rates of suckers in a large shallow earthen pond for comparison to growth in lined

ponds13

Figure13 4 Lined13 and13 earthen ponds13 of similar dimensions (approx 1000000 gallons first

and second panels) and a large13 shallow13 earthen13 pond (third panel)

38

13

Effect of sorting on growth

Razorback13 suckers13 are13 currently13 sorted13 after their first13 year of growth13 They are13

typically removed from13 one of the13 upper earthen13 ponds and13 split into13 two13 lined13 ponds for

subsequent grow-shy‐out13 The larger13 fish (gt approximately 140 mm) are placed into one pond

and the smaller individuals in another It is possible that the larger fish were more

aggressive or adept13 at taking food so this sorting process is intended to allow smaller fish

to improve their growth rate

Effect of Ich on razorback sucker growth rates

We13 evaluated13 growth13 rates13 of razorback sucker13 in the13 presence13 and absence of the

ectoparasite13 Ich (Ichthiopthirus multifiliis) Ich outbreaks can occur in wild populations13 but

hatcheries13 have13 proven excellent locations13 for Ich because13 of very high fish densities13 which13

facilitate13 the13 transfer13 of Ich13 between13 fish This common fish parasite causes direct mortality13

to razorback13 suckers as well13 as secondary bacterial13 infections13

The open spring and13 ditch13 which13 provides water to the Bubbling13 Ponds Hatchery

has long13 been infested with mosquitofish (Gambusia affinis) that harbor13 the13 Ich parasite13

and allow13 it13 to enter the hatchery with incoming13 water13 The solution13 to13 the13 Ich problem13

was to remove the mosquitofish host using13 Rotenone Razorback13 sucker growth13 rates were13

then tracked in13 the absence of this parasite for 4 months and compared with growth rates

after Ich returned to the pond and from13 previous years

Methods

Razorback growth rate in lined ponds

On May 14 2008 141 razorback suckers were tagged with 12 mm PIT tags (1342

kHz) and placed in Pond 3 (approximately 1100000 gallons13 Figure13 4)13 at Bubbling13 Ponds

Fish Hatchery Fifty-shy‐three of these tags were recovered two months later when a large

Ichthyophthirius multifilis (Ich) outbreak killed many fish in the pond On October 15 2008

an additional13 145 PIT tagged13 fish were13 also placed into Pond13 3 On13 May13 14 2009 Pond13 3

was harvested and a total13 of 141 PIT tagged fish were recovered13 Of the tagged fish13 26 fish

had13 been13 in the13 pond since May13 of 2008 (378 days13 o growth) and 115 had been13 in13 the

39

13 40

pond since October13 15 2008 (211 days13 of growth) Numbers of fish in Pond 3 after the Ich

outbreak and for the majority of the period of growth were between 3 000 and 4000 fish

A Hobotempreg temperature13 logger13 was13 also13 installed13 in Pond 3 one meter below the water

surface13 near13 the13 outflow and13 recorded water temperature every 3 hours to allow analysis

of the effects of water temperature on growth rate (Figure13 5) This Hobotemp data is

representative of other pond temperatures throughout this study

In a second experiment 210 adult13 razorback suckers13 were13 PIT tagged13 on13 May 14

2009 and13 placed13 into13 Pond13 3 upper to13 evaluate13 growth13 rates13 of larger13 razorback suckers13 at

Bubbling13 Ponds Hatchery13 under current13 rearing13 conditions13 Size of these fish at tagging13

was (mean = 285 mm range = 205 ndash 396 mm) These fish remained in the pond for 257

days and were harvested on Jan 25 2010 to provide information on growth rates of larger

razorback suckers13 under13 current rearing conditions

Figure 513 Temperatures (degC) inrearing pond at BubblingPonds Hatchery from July toSept 2009 (top graph)13 andfrom Nov to Dec 2009 (Lowergraph) Temperaturesrecorded with a Hobotempregremote data logger13 every 3hours

13

Growth rate13 in an unlined pond

To document razorback sucker growth in earthen ponds we introduced13 225 tagged13

razorback suckers13 into13 Pond13 1 lower13 (Figure 4) in February 3 2010 Additional tagged fish

from13 other studies were added to the pond throughout the growing season and the density

of 1 lower reached a maximum13 of nearly 7000 fish in early summer 2010 Density was

reduced to approximately 6000 fish by capturing fish with hoop nets on June 3 2010 54 of

these fish were tagged fish and returned to 1 lower after being weighed and measured The

pond was harvested on January13 2713 2011 and a total13 of 254 tagged fish out13 of 4296 fish

total were removed from13 the pond The pond was harvested on January 27 2011 (358 days13

of growth) and the tagged fish were weighed and measured Total number of razorbacks in

the pond at harvest13 was 4296

Effect of sorting practices on growth rates

On March 1113 200913 Pond13 5 upper was13 harvested13 and13 split into13 two13 separate13 groups

Two hundred of the smaller fish (average size = 122 mm TL) were PIT tagged and placed

into13 Pond13 7 upper and13 200 of the13 larger13 fish (average = 160 mm TL) were PIT tagged and

placed int Pond13 8 upper Density13 in Pond13 7 was13 4500 fish and13 in Pond13 8 there13 were13 6500

fish These ponds were then harvested after 1 year and growth rates were compared to

give information on the effects of current sorting practices Hobotempreg temperature

loggers were installed in13 Ponds 7 and13 8 during13 the13 grow-shy‐out period with13 water13

temperature recorded every 2 hours13 (Figure13 6)

Effect of Ich on razorback sucker growth rates

Bubbling Ponds spring was treated with Rotenone (CFT Legumine 5) at a

concentration of 2 ppm13 to remove all mosquitofish from13 the spring The treatment

consisted of two treatments 6 hours in duration on two consecutive days (April 12 -shy‐ 13)

using13 drip13 stations13 and13 backpack sprayers13 followed13 by13 an13 additional 6 hours13 of

detoxification using sodium13 permanganate Although 12 mosquitofish were captured in the

spring pond the week following the treatments subsequent minnow trapping (20 traps

checked13 daily13 for 3 weeks) did not capture any additional fish until August 11 2010 when

41

13

juvenile mosquitofish were again detected in the spring pond Minnow traps have

subsequently been set daily with several hundred individuals removed To evaluate if Ich

was also again present in the spring we captured 15 mosquitofish from13 the spring pond on

three separate days and placed them13 in an aquaria at 25 degC with 5 longfin dace known to be

free of Ich These fish were monitored for 2 weeks with no signs of Ich developing This

indicates that even though mosquitofish have returned to the spring pond the parasite is no

longer present13 although how13 long13 this condition13 will13 persist13 is unknown13

On May 1113 201013 200 juvenile razorback13 suckers were harvested out13 of Pond 5

upper (2009 year Class from13 Dexter National Fish Hatchery) and were PIT tagged and

placed into Pond 8 to evaluate if growth rates at bubbling ponds hatchery have improved

following the renovation of the spring and the removal of the Ich parasite Unfortunately13

on Sept13 8 2010 Ich was13 again13 detected13 in Pond 8 and the pond was immediately seined

and 74 tagged fish were measured to obtain growth information for the 4-shy‐month period

during13 which13 the13 pond13 was13 Ich-shy‐free13

Figure13 6 Temperatures (degC) in rearingponds 7 and 8 at Bubbling Ponds Hatchery13 from March 2009 ndash March 201013 pond 7(top13 graph)13 and13 pond 8 (Lower13 graph)13 Temperatures recorded with a Hobotempregremote data logger every 3 hours

42

13

Results

Growth in Lined Ponds

Razorback suckers13 that had been13 in13 Pond 8 upper for the13 entire13 year13 grew an13

average of 0263 mmday (789 mmmonth) and razorback suckers that had been in the

pond for 7 months (Oct -shy‐ May) grew13 on13 average of 028 mmday (843 mmmonth) (Figure13

7) These growth13 rates13 did not significantly13 differ Fish density13 in Pond 3 during13 the13

majority of the growth period was13 00032 ndash 00036 fishgallon13 Additionally no13 significant

differences in growth rate were observed between fish smaller than 210 mm TL and fish

larger than 210 mm TL when all recaptured fish were combined

We also measured the growth rate of very large fish in a lined pond On Jan13 2513 201013

156 adult fish with PIT tags were recovered from13 Pond 3 upper13 These fish were13 in the13

pond for 257 days and experienced an average13 growth13 rate13 of 024mmday or 73

mmmonth (Figure13 7)13 This growth13 rate13 is slightly13 lower13 than13 the13 average13 growth13 rate13

observed13 at Bubbling13 Ponds Hatchery in other studies (0275 mmday 825 mmmonth)

but may not be biologically meaningful We would expect larger13 fish to13 have13 reduced

growth rates according to a typical Von Bertalanfy growth model (Bertalanffy 1957) but it

appears that13 over the size range we evaluated (300 -shy‐ 450 mm TL) growth rates have not

slowed significantly compared to that of smaller13 fish grown at Bubbling Ponds13 Hatchery

Growth13 of razorback suckers13 is known13 to13 slow as13 fish reach13 larger13 sizes but it appears13 this13

reduced growth rate may not really start to be biologically meaningful at Bubbling Ponds

Hatchery13 until razorback suckers13 exceed 450 mm TL

Growth in unlined ponds

Growth13 rates13 for the13 fish recaptured13 during13 the Pond 1 lower13 thinning13 (120 days13 in

the pond) was 024 plusmn 003 mmday (729 plusmn 090 mmmonth) (Figure13 8)13 Fish13 that were13 in

the pond for nearly the entire year grew13 an13 average13 of 024 plusmn 001 mmday (726 plusmn 027

mmmonth) These growth rates are surprisingly the lowest measured growth rates for

any part of our study and differ significantly from13 every other measured growth rate

except very large13 fish (Figure13 9)13 Separating13 out13 large fish that13 were in13 the pond for the

entire year makes no difference fish that were added to the pond at TL lt300 mm grew

43

13

Gro

wth

Rat

e (m

md

ay)

020

026

032

0244 plusmn 001 mmday (733 plusmn 028 mmmonth) and and those with TL gt= 300 mm at the

start of the experiment grew 022 plusmn 003 mmday (651 plusmn 101 mmmonth)

Razorback Growth Rates in Lined Ponds

Figure 7 Growth ofrazorback suckers in(mmday plusmn standard error)in Pond 8 upper in 2008-shy‐2009 An ANOVA did notdetect any significantdifferences

7 Months Full Year 300+ mm fish

Effects of sorting on growth

One hundred and seventy five tagged razorback suckers were recovered from13 Pond

8 upper13 on March13 24 2010 (378 days13 of growth)13 These were13 the13 larger sorted13 fish (gt140

mm TL) that came out of Pond13 5 on March13 11 2009 One13 hundred and13 twenty13 two13 tagged13

razorback suckers were also recovered from13 Pond13 7 upper on March13 31 2010 (385 days13 of

growth)13 These were13 the13 smaller sorted13 fish (lt140 mm TL) that came out of Pond13 5 on

March 1113 200913 No significant differences in growth rate (mmday) were observed among

larger fish in Pond 8 and smaller fish in Pond 7 (pgt005 ANOVA) (Figure 10)13 indicating

that13 sorting may have helped to offset the original slower growth trajectory of the smaller

fish Temperatures of Ponds 7 and 8 upper remained similar throughout the year13 (Figure

5)

44

13

13

13

Gro

wth

Rat

e (m

md

ay)

Gro

wth

Rat

e (m

md

ay)

020

026

032

020

026

032

Razorback Growth in an Unlined Pond

Figure 8 Growth of razorbacksuckers (mmday plusmn standard error) in Pond 1 lower (an unlined pond)in 2010-shy‐2011 An ANOVA did notdetect any significant differences

6 Months 12 Months lt 300 mm Fish 300+ mm Fish Growth Growth

Lined vs Earthen Ponds 1 year of growth

Figure 9 Growth of razorbacksuckers (mmday plusmn standard error) in lined and unlined ponds A t-shy‐test13 did not detect a significantdifference

Lined Pond Unlined Pond 1 Yr Growth 1 Yr Growth

45

13

Effect of Sorting G

row

th R

ate

(mm

day

) G

row

th R

ate

(mm

day

)

032

020

026

032

020

026

Smaller Fish Larger Fish

Effect of Ich

Figure 10 Average growthof razorback suckers(mmday plusmn standard error)that were size-shy‐sorted intosmall fish (pond 7) and largefish (pond 8) populations At-shy‐test did not detect asignificant difference

Figure 11 Average growth ofrazorback suckers (mmday plusmnstandard error) after Ich wasremovd from the hatcheryrsquos springand after Ich was again detected inthe pond The growth rate withoutIch is significantly higher than boththe rate after Ich and the ourstudyrsquos average annual growth ratein lined ponds (ANOVA p =00003)

Growth without Ich Growth With Ich Average Annual 4 months 4 months Growth Rate

46

13

Effect of Ich on razorback sucker growth rates

Seventy-shy‐four13 tagged13 razorback suckers13 were13 recovered from13 Pond 8 on September

15 2010 These fish had13 been13 in the pond for 4 months and experienced a growth rate of

032 mmday or 97 mmmonth (Figure13 11)13 This growth13 rate13 is significantly higher (p =

005 two sample t-shy‐test) than the mean growth rate for the same group13 of tagged fish after

Ich detection (022 mmday or 65 mmmonth) and significantly higher than any other

individual growth13 rates13 observed13 to13 date13 at Bubbling13 Ponds Hatchery13 (Figure13 11)13 If this13

growth13 rate13 were13 extended throughout13 the entire13 year13 fish on average from13 Ich-shy‐free13 ponds13

would be 16 mm longer than fish from13 ponds infested with Ich Studies conducted at

Bubbling Ponds hatchery in 2008 (Ward 2008) did not reveal any effects of the treatment

chemicals on razorback sucker growth rates so it13 is likely that13 the parasite outbreaks

themselves are causing reducing growth rates rather than the chemicals used to treat the

parasites13

Conclusions

Our results suggest that under typical hatchery operations (maximizing number of

fish produced)13 the growth13 rate13 of razorback13 suckers13 is relatively13 consistent at Bubbling13

Ponds hatchery13 at 02-shy‐03 mmday (6-shy‐9 mmmonth)13 but is lower than growth13 rates13 at

other13 facilities (02 ndash 18 mmday Ward et al 2007)13 This growth13 rate13 has13 been13 constant in

both lined and unlined ponds and at all fish densities we were able to measure To achieve13

growth13 rates13 substantially higher than this will likely require13 significant changes in rearing

practices that may not be practical in order to reach numerical production13 goals

Temperature is a key variable in fish growth but seasonal growth patterns

described13 above13 (Figure13 5) demonstrate that water temperatures are high enough in

winter to maintain razorback growth Differences in water temperature by season

currently13 do not fluctuate more than 10degC at Bubbling Ponds because of the continuous

supply of water flowing through each pond (approx 225 gallonsmin) These high water

flows appear to keep pond temperatures within the thermal preference13 for razorback

suckers13 (1213 -shy‐ 28 degC Bulkley and Pimentel 1983) throughout the entire year with

temperatures rarely dropping13 below 16deg13 C (Figures 513 6)13

47

13

Fish density is another key variable in fish growth and though the number of fish in

a pond during our study ranged from13 3000 to 700013 fish we13 did not find any13 correlation13

between13 density and growth rate13 This might yield two conclusions First13 razorback

growth13 may be changed equally13 by13 densities13 at the13 hatchery13 (ie13 a density13 of 3000 fish in a

pond is as stressful13 for razorbacks as a density13 of 7000 fish) An alternative is that other

factors13 such as disease outbreaks have13 stronger13 control over fish growth13 than13 density13

Fish density13 would13 have13 to13 be13 experimentally manipulated to test13 this13 and hatchery

operations (producing the maximum13 number of fish) prevented our manipulating density13

in ponds for this13 work The trouble with manipulating density demonstrates the difficulties

associated with changing13 hatchery13 practices experimenting with density would have

prevented BPH from13 meeting13 production13 goals Given that the stocking of smaller

razorbacks has met with very little success perhaps BPH goals could be changed from13

producing 12000 fish at 300+ mm per year to a smaller number of very large fish each

year Growing13 fewer13 larger13 fish could potentially be accomplished in the same time frame

as more smaller fish but a better understanding of how density alters growth rate would

be required to be confident13 of this

The very slow growth13 in the13 earthen13 unlined13 Pond 1 lower13 was very surprising We13

had13 anticipated13 that the13 diversified diet13 cover and13 other13 habitat features13 provided by13

unlined ponds would yield dramatically increased growth rates However these traits were

not enough to offset high fish densities and in fact the unlined pond in our study13 suffered

mortality to bring densities down to that observed normally in lined ponds

Our data13 suggest13 that razorbacks13 sucker13 growth13 rates13 are13 higher in lined13 ponds13

However we13 think the reasons13 for the13 very slow growth we observed13 in the13 unlined13 pond13

in our study13 is instead13 linked13 to13 the13 usage13 of Pond 1 lower13 during13 the13 study13 rather13 than13

intrinsic13 slow growth13 in earthen13 ponds First the pond was at extremely high density for at

least part of the study The volume of Pond 1 lower has not been estimated but hatchery

managers suggest 1500-shy‐2000 fish is an appropriate number of individuals so this pond

was at a very high density for much of the experiment Second dissolved oxygen is often

very low in the13 large13 earthen13 ponds during the heat of summer much lower than that of

lined ponds This will both limit the number of fish that can survive in the pond and almost

certainly13 increases stress13 of these13 fish potentially13 reducing growth13 The DO crashes also13

48

13

limit the amount of feed hatchery managers can give fish in these ponds sometimes for

days or weeks at a time which further reduces growth during warm13 weather

Our data13 suggests that13 growth rates at the Bubbling13 Ponds Fish Hatchery are likely

as high as possible given13 the pond densities required to meet production goals and the Ich-shy‐

infested water that feeds the facility Sorting practices are successful in helping as many

fish as possible reach stocking length as fast as possible Unlined ponds may be able to

grow13 large13 fish at low13 densities13 but whatever factors allow13 for that13 growth are not13 able to

overcome high fish density The removal of invasive13 fis that act as13 a host for the13 parasite13

Ich fish from13 the Bubbling13 Ponds spring13 allowed the highest13 growth rate at 032 mmday13

(96 mmmonth) but that growth rate decreased again as Ich re-shy‐infested13 the13 hatchery13

Consistently13 achieving13 growth13 rates13 as high or substantially13 higher than13 this13 will likely13

require13 significant changes in rearing practices that may not be practical in order to13 reach13

numerical production13 goals

Two major changes that might result in higher growth rates are substantially

reducing fish density and modifying the way spring water is delivered to the facility (via

either repeated chemical treatments or enclosed concrete water diversions) to eliminate

Ich from13 the hatchery source water Other potential changes not address by our work

include13 flow-shy‐training razorbacks much previous literature including MSCP-shy‐funded13 work

on razorback suckers13 suggests13 that fish growing13 in flowing water will grow13 faster than fish

in still water (Jorgensen and Jobling 1994) Furthermore there are a wide variety of

potential benefits associated with growing13 fish13 in flowing13 water in addition13 to increased

growth13 rates13 (Davidson13 199713 Castro13 et al13 2011) Another option13 for increasing13 growth13

rates13 include13 changing to13 intensive13 culture13 in large circular13 tanks

Finally given that the stocking of smaller razorbacks has met with very little

success13 perhaps13 BPH13 goals13 could13 be13 changed from13 producing 12000 fish at 300+ mm per

year to a smaller number of very large fish each year Growing fewer larger fish could

potentially be accomplished in the same time frame as more smaller fish but a better

understanding13 of how density13 alters growth13 rate13 would13 be13 required to13 be13 confident of this

49

13

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower13 Colorado13 River Multi-shy‐Species13

Conservation Program13 (LCRMSCP) under Work Task C10 We13 thank Ty Wolters13 Tom13

Burke13 and Eric13 Volkman for their support of this research and Frank Agygos and Dave

Billingsly13 of the Bubbling13 Ponds Fish Hatchery13 for their willingness to participate in13 this

research13 and13 for their technical assistance We also thank the LCRMSCP fish group from13

Boulder City13 NV for their assistance with harvesting13 ponds and tagging13 fish13

50

13

Literature13 CitedAnders P J 1998 Conservation aquaculture and endangered species can objective science13

prevail13 over risk13 anxiety Fisheries 23(11) 28-shy‐31

Anderson R O and R M Nuemann 1996 Length weight and associated structural indicesPages 447 ndash 482 in B R Murphy13 and D13 W Willis13 editors13 Fisheries techniques13 2ndedtion American Fisheries13 Society13 Bethesda13 Maryland

Bain M B J T Finn and H E Brooks 1988 Streamflow regulation and fish communitystructure13 Ecology13 69382-shy‐392

Bays J H Zarbock R Whitman and T Murphy 2005 Conceptual design and managementof native13 fish refugia on the13 lower13 Colorado13 River In13 CL Spring13 and13 S Leoneditors Proceedings of two symposia Restoring native fish to the lower ColoradoRiver13 interactions13 of native and non-shy‐native13 fishes 13ndash1413 July13 1999 Las13 Vegas13 Nevada13 Restoring13 natural function within a modified riverine environment thelower Colorado River13 8ndash913 July13 1998 U S Fish and13 Wildlife13 Service Southwestern13 Region Albuquerque New Mexico Pages 167-shy‐177

Bertalanffy L Von 1957 Quantitative laws in metabolism13 and growth13 Q Rev Biology 32217 ndash 231

Bingham T B Scheer and C McAda 2003 Propagation facilities in Grand Valley (24 RoadHatchery Horsethief13 Ponds and13 grow-shy‐out ponds) for captive13 rearing13 ofendangered13 fishes for the13 upper13 Colorado13 River basin13 Colorado River RecoveryProgram FY2003 annual project report13 US Fish and13 Wildlife13 Service GrandJunction13 4pp

Birchell G J and K Christopherson 2004 Survival growth and recruitment of larval andjuvenile razorback13 sucker (Xyrauchen texanus) introduced13 into13 floodplain13 depressions13 of the13 Green River Utah13 Final report13 Upper13 Colorado13 RiverEndangered Fish Recovery Program13 Project No C-shy‐6RZ Publication Number 04-shy‐1513 Utah13 Division of Wildlife13 Resources Salt Lake13 City13 Utah13 67 pages

Brannon E L 1993 The perpetual oversight of hatchery programs Fishery Research 1819-shy‐27

Brett J R 1979 Environmental Factors and growth pages 599-shy‐67513 InW S Hoar13 D13 J13 Randall and J R Brett (eds) Fish Physiology Volume 8 Bioenergetics and GrowthAcademic Press New York

Brooks J E 1986 Annual reintroduction and monitoring report for razorback suckerXyrauchen texanus in the Gila River Basin Arizona 1985 US Fish and WildlifeService13 Offices of Endangered13 Species and Fishery13 Resources Albuquerque 23 pp

51

13

Brunson13 R E and K D13 Christopherson13 200513 Larval13 razorback13 sucker and bonytailsurvival and13 growth13 in the13 presence13 of nonnative13 fish in the13 Baeser13 floodplainwetland of the middle Green River Final report prepared for Upper13 Colorado RiverBasin Endangered Fish Recovery Program Project No C-shy‐6-shy‐rz-shy‐bt Publication13 No 05-shy‐26 Utah13 Division of Wildlife13 Resources13 Vernal13 32 pp

Bulkley R V and R Pimentel 1983 Temperature preference and avoidance by adultrazorback suckers Transactions of the American Fisheries Society 112601-shy‐607

Burke13 T13 199513 Rearing13 wild razorback13 sucker larvae in13 lake-shy‐side13 backwaters13 LakeMohave ArizonaNevada Proceedings of the Desert Fishes Council 2635

Busacker G P I R Adelman and E M Goolish13 199013 Growth13 Pages 363 ndash 387 in C BSchreck and p B Moyle editors Methods for fish biology American FisheriesSociety Bethesda Maryland

Castro V B Grisdale-shy‐Helland S J Helland T Kristensen S M Jorgensen J Helgrud13 GClaireaux A P Farrell A Krasnov and H Takle 2011 Aerobic training stimulatesgrowth and promotes disease resistance in Atlantic salmon (Salmo salar)Comparative Biochemistry and Physiology -shy‐ Part A Molecular amp IntegrativePhysiology13 160(2) 278-shy‐290

Czapla T E 2002 Facilities plan for the production of endangered fishes to meet statestocking13 plans13 as13 part of the13 Upper13 Colorado13 River Endangered13 Fish RecoveryProgram Upper Colorado River Basin Recovery Implementation Program US Fishand Wildlife Service13 Denver13 9 pp

Davidson W 1997 The effects13 of exercise13 training on teleost fish a review of recentliterature Comput Biochem Physiol 117A67ndash75

Figiel Jr C R 2005 Annual report fiscal year 2004 Willow Beach National13 Fish HatcheryUS Fish and Wildlife13 Service Willow Beach 17 pp

Figiel Jr C R M E Ulibarri G Carmichael J Seals and J N Hanson 2005 Intensive13 fish13 culture of warmwater native fishes at a coldwater fish hatchery Pages 164-shy‐16613 inProceedings of two symposia restoring native fish to the lower Colorado13 River13 interaction13 of native13 and13 non-shy‐native13 fishes July13 13-shy‐1413 1999 Las Vegas Nevada USFish and Wildlife Service Southwest Region Albuquerque New Mexico

Gerking13 S D 1978 Ecology of freshwater fish13 production13 Halstead Press13 New13 York

Gustafson W and Q Bradwisch 2000 Wahweap operation and maintenance -shy‐-shy‐ UtahColorado River Recovery Program FY 2000 annual project report Project No 29cUtah13 Division of Wildlife13 Resources Page AZ 3pp

52

13

Hamman R L 1985 Induced spawning of hatchery-shy‐reared13 razorback sucker ProgressivFish Culturist 47(3) 187-shy‐189

Hanson J N 1996 Annual report fiscal year 1996 Willow Beach National Fish HatcheryUS Fish and Wildlife Service13 Willow Beach 9pp

Irving D S Seversen and M Montagne 2004 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2004 annual project13 report Report No 29b US Fish and13 Wildlife13 Service Vernal 3pp

Jorgensen E H and13 M Jobling 1994 Feeding and13 growth13 of exercised13 and13 unexercised13 juvenile Atlantic salmon in freshwater and performance after transfer to seawaterAquaculture International 2 154-shy‐164

Kaeding L R and D B Osmundson 198913 Colorado13 Squawfish13 and13 razorback sucker grow-shy‐out pond studies as part of conservation measures for the green mountain andRuedi reservoir water sales Final report for agreement number 6-shy‐AA-shy‐60-shy‐00150

Koebele13 B P13 198513 Growth and the size hierarchy effect an experimental assessment ofthree proposed mechanisms activity differences disproportional food acquisition13 pysiological stress Environmental Biology of Fishes 12 181-shy‐188

Kretschmann A E and L L Leslie 2006 Razorback sucker (Xyrauchen texanus) status13 reproduction and recruitment in Senator Wash Reservoir CA Final Report13 to USBurea of Reclamation Cooperative Agreement No 00-shy‐FG-shy‐34-shy‐ 0009 p 32 ArizonaGame and Fish Department Phoenix

Marsh13 P13 C13 1987a13 Digestive tract13 contents13 of adult razorback suckers13 in Lake13 MohaveArizona-shy‐Nevada Transactions of the American Fisheries Society 116117-shy‐119

Marsh P C 1987b Native fishes at Buenos Aires National Wildlife Refuge and ArizonaState University Research Park Arizona opportunities for management researchand public13 education13 on13 endangered species13 Proceedings of the Desert13 FishesCouncil 1967-shy‐78

Marsh P C 1994 Rearing native Colorado River fishes in golf course ponds Arizona StateUniversity Tempe 22 + pages

Marsh13 P13 C13 200013 Fish population13 status and evaluation13 in13 the Cibola13 High Levee PondFinal report agreement number 99-shy‐FG-shy‐30-shy‐00051 US Bureau of ReclamationBoulder City13 Nevada13 20 pages

Marsh P C and C A Pacey 1998 Growth of wild adult razorback suckers13 in Lake13 Mohave13 Arizona-shy‐Nevada13 Final report13 US Bureau of Reclamation Boulder City Nevada 25pages + appendices

53

13

Marsh P C B R Kesner and C A Pacey 2005 Repatriation as s management strategy13 to13 conserve a critically13 imperiled fish species North American Journal of FisheriesManagement 25 547-shy‐556

Marsh P C and C A Pacey 2005 Immiscibility of native and non-shy‐native13 fishes Pages 59-shy‐63 inMJ13 Brouder13 CL13 Springer13 and CS13 Leon13 editors13 Proceedings of two13 symposia Restoring native fish to the lower Colorado River interactions of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 NV and13 Restoring natural13 function within a modified riverine environment the lower Colorado River13 July13 8-shy‐913 1998 Las Vegas NV US Fish and13 Wildlife13 Service Southwest Region AlbuquerqueNew Mexico

Marsh13 P13 C13 and J13 E Brooks13 198913 Predation13 by ictalurid catfishes as a deterrent13 toreestablishment of hatchery-shy‐reared13 razorback sucker The Southwestern Naturalist34188-shy‐195

Matthews R A 2005 Ichthyopthirus multifiliis Fouquet and Ichthyopthirosis infreshwater13 teleosts13 Pages13 159-shy‐218 in Advances in Parasitology volume 59 J RBaker R Muller D Rollinson (eds) Academic Press

McCarthy13 M S and W L Minckley 1987 Age estimation for razorback sucker (PiscesCatostomidae) from13 Lake Mohave Arizona and Nevada Journal of the Arizona-shy‐Nevada Academy of Science 2187-shy‐97

Minckley13 W L13 198313 Status of the razorback13 sucker13 Xyrauchen texanus (Abbot)13 in13 thelower Colorado River basin13 The Southwestern13 Naturalist13 28(2) 165-shy‐187

Minckley13 W L13 199113 Native fished of the Grand Canyon13 region an obituary13 Pages 124-shy‐177 in Colorado River ecology and dam13 management National Academy PressWashington13 DC

Minckley13 C13 O and M LaBarbara13 199913 Report13 on13 native fish grow-shy‐out facilities13 at Cibolaand Imperial National Wildlife Refuges 1993-shy‐199513 US Fish and13 Wildlife Service13 Parker Fishery Resources Office Parker Arizona

Modde13 T13 199613 Juvenile razorback sucker (Xyrauchen texanus) in a managed wetlandadjacent13 to the Green13 River13 Great13 Basin13 Naturalist13 56375-shy‐376

Modde T KP Burnham and E J Wick 1996 Population status of the razorback sucker13 inthe middle Green River (USA) Conservation13 biology 10 110-shy‐119

Modde13 T13 and G13 B Haines13 200513 Survival13 and growth of stocked razorback13 sucker andbonytail in multiple floodplain wetlands of the middle Green River under resetconditions13 Final report prepared for Upper Colorado13 River13 Basin RecoveryImplimentation Program US Fish and Wildlife Service Vernal 66 pp

54

13

Modde T Z H Bowen and D C Kitcheyan 2005 Spatial and temporal use of a spawning13 site in the middle Green River by wild hatchery-shy‐reared13 razorback suckers13 Transactions of the American Fisheries Society 134937-shy‐944

Mueller13 G13 199213 The native fish work13 group13 -shy‐ a multiagency endeavor to improve thestatus of the razorback sucker in Lake Mohave AZ-shy‐NV13 Proceedings of the DesertFishes Council 2369

Mueller G 1995 A program13 for maintaining the razorback sucker in Lake MohaveAmerican Fisheries Society Symposium 15127-shy‐135

Mueller13 G13 200613 Ecology of the bonytail13 and razorback13 sucker and the role of offchannelhabitats13 in their13 recovery Scientific13 investigations13 report 2006-shy‐5065 US GeologicalSurvey13 Denver

Mueller G and E Wick 1998 Testing of golf course ponds at Page Arizona for suitability13 as grow-shy‐out facility for razorback sucker using surplus fish from13 Ouray NationalFish Hatchery National Park Service US Fish and13 Wildlife13 Service and UtahDivision of Wildlife13 Resources 28 pages

Mueller13 G13 and T13 Burke13 200513 Survival13 of young13 razorback13 sucker (Xyrauchen texanus) inrelation to13 stocking rates13 (fishha)13 and13 in the presence13 or absence13 of predatorcommunities in Lake Mohave Arizona-shy‐Nevada13 Pages13 155-shy‐16313 in Proceedings of two13 symposia restoring native fish to the lower Colorado River interaction13 of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 Nevada US Fish and Wildlife13 Service Southwest Region Albuquerque New Mexico

Mueller13 G13 J13 Carpenter13 and P13 C13 Marsh13 200413 Cibola13 High Levee Pond annual report 2004US Geological Survey Fort Collins13 Science Center13 Colorado13 and Arizona StateUniversity Tempe 23 pages

Nesler T P K Christopherson J M Hudson C W McAda F Pfeifer and T E Czapla 2003An integrated stocking plan for razorback sucker bonytail and Colorado13 pikeminnow for the Upper Colorado River Endangered Fish Recovery ProgramAddendum13 to State Stocking Plans Upper Colorado River Basin Recovery13 Implementation Program 12 pp

Papoulias13 D and W13 L Minckley13 1992 Effects13 of foo availability13 on survival and growth13 of larval razorback suckers13 in ponds Transactions of the American Fisheries Society121340-shy‐355

Paukert13 C P D L Ward13 P J Sponholtz13 and K13 D Hilwig13 Effects13 of repeated hoopnetting13 on bonytail chub13 Journal of Freshwater13 Ecology13 20(4) 649-shy‐653

Pfeifer F M13 C Baker13 and M13 Montagne13 199913 Propagation13 facilities13 in the13 Grand Valley13 (24 Road13 Hatchery13 Horsethief13 Ponds and13 grow-shy‐out ponds) for captive rearing of

55

13

endangered13 fishes for the13 Upper Colorado13 River Basin13 Colorado13 River Recovery13 Program FY 99 annual project report Project No 29a13 US Fish and Wildlife Service13 Grand13 Junction13 5pp

Pfeifer F S Seversen and M Montagne 2003 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2003 annual reportProject No 29b13 US Fish and Wildlife13 Service Vernal13 4pp

Rabago-shy‐Castro J L Sanchez13 J G Perez-shy‐Castaneda R and13 Gonzalez-shy‐Gonzlez A 2006Effects of the prophylactic use of Romet-shy‐3013 and13 copper13 sulfate13 on growth13 condition13 and feeding13 indicies in13 channel13 catfish (Ictalurus punctatus) Aquaculture 253 343-shy‐349

Reinitz GL L E Orme and F N Hitzel 1979 Variations of body compositio and growth13 among strains of rainbow trout Transactions of the American Fisheries Society 108204-shy‐207

Ruppert13 J13 B P B Holden13 and P D Abate 1999 Age estimation and growth of razorbacksucker13 Xyrauchen texanus in Lake13 Mead Nevada Proceedings13 of the Desert FishesCouncil 3040

Schnoor K D and J Logan 2002 Operation and maintenance of JW Mumma nativeaquatic13 species restoration facility Colorado Colorado River Recovery Program FY2002 annual project report13 Project No 29d Colorado13 Division of Wildlife Alamosa3pp

Salisbury13 L13 1998 Factors13 affecting razorback13 sucker growth13 in Lake13 Mohave backwaters13 MS Thesis13 Unviersity13 of Nevada13 Las13 Vegas

Schooley J13 D13 and P C13 Marsh13 2007 Stocking of endangerdd13 razorback13 suckers13 in thelower Colorado River Basin13 over three decades 1974-shy‐2004 North American Journalof Fisheries Management 27 43-shy‐51

Severson S H H M Tyus and G B Haines 1992 An evaluation of feeds for raisingrazorback sucker Xyrauchen texanus Journal of Applied Aquaculture 155-shy‐65

Toney D P 1974 Observations13 on the13 propagation13 and13 rearing13 of two13 endangered species13 in a hatchery environment Proceedings of the Annual Conference of the Western13 Association of State Game and Fish Commissions 54 252-shy‐259

Tyus H M13 1998 Razorback sucker13 (Xyrauchen texanus) recovery plan13 University13 ofColorado Center for Limnology Boulder13 76 pages

Tyus H M13 and13 S H Severson 1990 Growth13 and13 survival of larval razorback suckers fedfive formulated diets The Progressive Fish Culturist 52197-shy‐200

56

13

Ulibarri M E 2003 Annual report fiscal year 2001 Dexter National Fish Hatchery13 andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 26 pages

Ulibarri M E 2003 Annual report fiscal year 2002 Dexter National Fish Hatchery andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 59 pages

USBR 2006 Lower13 Colorado13 River Multi-shy‐Species Conservation Program final fishaugmentation plan Boulder City 19 pp

USFWS 2002 Razorback sucker (Xyraouchen texanus) recovery goals Amendment andsupplement to the Razorback Sucker Recovery Plan13 US Fish and Wildlife Service13 Region 6 Denver13 Colorado

USFWS 1999 Annual report 1999 Ouray National Fish Hatchery Vernal 25pp

USFWS 2004 Management plan for the big-shy‐river13 fishes of the13 lower13 Colorado13 river basinamendment and supplement to the bonytail humpback chub Coloradopikeminnow and razorback sucker recovery plans

USFWS13 2005 Station13 profile13 of the13 Dexter13 National Fish Hatchery13 and Technology CenterUS Fish and Wildlife13 Service Dexter

Valdez R A P G Mangan R Smith and B Nilson 1982 Upper Colorado River fisheriesinvestigations13 inW H Miller J J Valentine D L Archer H M Tyus R A Valdezand L13 Kaeding13 editors13 Colorado River Fishery13 Project13 Part 2 Field13 investigations13 US Bureau of Reclamation Salt Lake City Utah

WBNFH 2004 Culture methods of the endangered razorback sucker Xyrauchen texanusUS Fish and Wildlife13 Service Willow Beach National Fish Hatchery13 8 pp

Ward D 2008 Effects of disease treatments on growth of razorback sucker ReportSubmitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 Inpartial fulfillment of work task C10 agreement number 06FG30039

Ward13 D13 M Childs and W Persons 2007 Factors13 affecting13 growth13 of razorback sucker13 (Xyrauchen texanus) in captivity Literature review and knowledge assessmentReport Submitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 In partial fulfillment of work task C10 agreement number 06FG30039

57

Appendices

Appendix 1 Survey Questions Survey of Razorback Sucker Culture in the

Southwestern United States

The enclosed survey is being distributed by the Arizona Game and Fish Department to razorback sucker culture facilities throughout

the Southwestern United States The purpose of this survey is to consolidate information regarding culture of this species so that

appropriate facility improvements can be considered for Bubbling Ponds Hatchery in Arizona Specifically we wish to increase

growth rate and production efficiency at the hatchery Information gathered in this survey will be summarized in a final report to US

Bureau of Reclamation in Boulder City NV and disseminated to all facilities that participate in the survey A workshop to discuss

the findings of this study as well as to share general information concerning razorback sucker culture will be organized by the

Arizona Game and Fish Department at the conclusion of this study and all participants will be invited

Thank you for taking the time to fill out this survey Please contact Mike Childs if you have questions or would like to discuss the

survey

Mike Childs

mchildssedonanet

(928) 639-1346

(928) 634-1279

Facility_____________________________________ Date___________________

Contact Phone _____________________________

ContactPerson_______________________________

Contact Email _______________________________

1 Water quality ranges at this culture facility

Season

Spring (Mar-May) Summer (Jun-Aug) Fall (Sept-Nov) Winter (Dec-Feb)

Temperature (C)

PH

DO (mgL)

PO4 (mgL)

TDS (mgL)

Hardness (mgL)

CaCO3

Pathogens

37

13

Oct) and fed the Bozeman razorback diet two times a day five days a week at 15 ndash 30

body weight per day based on average water temperature

Figure 1 Relationship between length and number of fish per pound

In general13 juvenile razorback13 suckers (received as fry13 during13 the previous spring)13

reach the target size of 300 mm TL in approximately 6 months In 20062007 Uvalde

produced 6000 razorback suckers 300 mm TL for introduction into the San Juan River

Starting13 in 2008 Uvalde NFH will be producing13 and distributing13 12000-shy‐ 300 mm TL

razorbacks for stocking into the San Juan River Predation from13 migrating cormorants has

occurred but timing of harvest and over wintering protection methods such as covering

ponds with netting or placing fish indoors helps to minimize losses during the cormorant

migration (November to March) Uvalde has experienced razorback mortalities because of

bacterial problems but these are usually resolved through the use of oxytetracyline

medicated feed

Overview13 of Differences in Culture Methods

Several differences were noted when conducting surveys at each of the five main

production facilities for razorback sucker (See Appendix 3) These differences include

different stocking13 and13 rearing13 densities13 (Table13 4-shy‐5) various feeding regimes and type of

18

13

lt=amp

feeds (Table 7) as well as differences in grading or sorting practices Some of these

differences are13 related13 to13 whether13 or not razorback suckers13 are13 being13 reared13 in extensive-shy‐

culture13 facilities13 (ponds) or intensive-shy‐culture13 settings13 (raceways13 o tanks)13 Some13 practices13

are unique to a single facility13 or a couple of facilities (Table 6)13 Managers at each facility13

were asked to identify the biggest13 difficulty or constraint13 that13 they experience when13

growing-shy‐out juvenile13 razorback suckers13 at their13 respective13 location13 Space constraints13

water quality and disease problems were the main factors limiting production of razorback

suckers13 at these13 facilities13 (Table13 8) Calculated or reported growth rates from13 the literature

vary widely (Table 9) and range from13 02 to 18 mmday These growth rates indicate that

juvenile razorback suckers have a very high growth potential under optimal rearing

conditions13

Table13 4 Stocking13 densities13 for larvae13 and13 fry in ponds

$amp( )(+amp-( 01-2(3(4amp56( 4amp56(+amp-( 01-2782-( $amp () + --amp +amp0amp)+amp 12-3amp ( )+amp0amp+amp --amp +amp0amp)+amp 42556789amp8 ( +amp0ampgt+amp 3amp +amp0amp+amp A-BC-Damp (E + 3amp )+ F-6ltamp ) G+ 3amp G+

Table13 5 Rearing13 densities13 at intensive13 culture13 facilities13

$amp( )amp+(($-( $0( 12(3$+( 40((amp05( 67((amp05( 8$9(407$( $amp amp())amp++-$amp 0 1 0amp2amp1amp 3amp2amp4 0544

6amp())amp++-$amp 610 021 4amp2amp47amp 3amp2amp77amp 058 9$amplt+)amp 4amp())amp++-$amp 00 1 7amp2amp77amp 851amp2amp0amp 05

6amp())amp++-$amp 610 77amp2amp1amp 0amp2amp1amp 053

19

13

Table13 6 Rearing13 practices13 that are13 unique to13 specific rearing13 facilities13 $$amp( )$+-(amp$-(0(1-amp2034( $amp()amp+( -0$(12(33+(amp(amp134$53+(amp$amp3+(6amp+(

723(843(1$8(422(6amp+(42amp(4(423(19$43( 343( lt34$53(6amp+(6(4($03(amp4+94amp(842($1$1(63$$34(amp+(63626243( =amp+(gtamp94ampA( B3(1(1$+53+C3+(amp+(1$43(1(3D0$(1(amp443(amp+(amp443( 734231(amp( B3(1(193(44(1(34amp(amp(+49E(6amp+( -E3(F3+( G3amp(1(12(amp(H3(13$(4ampE(C(IJK($$amp( A( L43(+A3(4(6303amp4(63+4ampM(66$3D3amp4$(34amp(amp(6amp+(C((4amp3( L$$8(392(

B0$+3(

N43D(13+(4($0$(12M(amp+(639$53+($0$(12(+34( G3amp(12(amp(399$4amp(4+(938A(842($(2343+(843( N443D643+(3amp(12(amp(amp34(63amp(amp(423(O$+(G03( )amp+(3(134$53+(6(4(39364(1(1A(4(44(423D(amp((D3(amp4$(+34(

Table13 7 Types of feed used at razorback sucker13 hatcheries13 $amp ()amp+-amp0- $$)1amp23 45-amp)-$5)1amp23 $amp()amp+( -amp$amp+(amp+( -amp012$3+(amp+4(amp5215$(0+( 65ampamp7(85209(+2($1(87((15315lt=(+2(

+amp+amp(amp(55$5$2gt( 21( Aamp+(amp+( )amp+(012$3+(B29(5$05$95($$2(5amp+(

199524(amp5215$(0+( 65ampamp7(85209(+2($1(87(15315lt=(+2(amplt( 29gt(51($51(amp9(2(25=(C(DD(0+(

E15amp+(Famplt2amp( G1$5(lt1lt$51(25amp=( HIJKH(Dlt1amp(15315lt=(+2(I(C2(CH(+5gt( )11$gt($511(02+(15315lt=(+2(

$1(87(15315lt=(+2(D5$$(3(lt5$$gt(02+(gt( 6lt=(511B(

L15gt( G1$5(lt1lt$51(25amp=(Aamp+( amp+(

HIJKH(Dlt1amp(15315lt=(+2(I(C2(CH(+5gt( )11$gt($511(02+(15315lt=(+2(

$1(87(15315lt=(+2($1(87($B(amp=amp( 5$Damp(+2(

M$$B(5lt9(-5$+( NO515(G1$5(219( L2+1(15ltB5gt(Aamp+(5amp+( amp$amp+(amp+(

1amp(91D(amp5$(Pamplt5$amp4( 8gtlt$34(1$amp54(5amp+(5120lt5$( $5amp=2amp()amp+(012$3+(B29(5$05$95( $$2(5amp+(19952Q(amp12152( 1+lt2amp(

$1(87(15315lt=(+2($1(87(15315lt=(+2( $1(87(15315lt=(+2(

Table 8 Factors limiting production at major razorback sucker facilities

$amp( )amp+(-0+1((2$(0amp1ampamp(-34amp( $amp()amp+( -(01$2(34+(546(amp(0amp(01amp(541(13( -741( 803(3amp41amp4(9((+ltlt1amp4(03(amp(44amp(2=(4(

+ltlt3$4(4(2amp4amp(014(1gt13=(43=( 1amp+(amp34amp( 803(3amp41amp4(1$4+(4(541(A$4B(amp+(+$C+(

7Bamp($244amp(lt(1313$4amp(B42( D1B( E41(A$4B(01$2(3+(B(66(1amp(amp+(2ampamp(

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Table9Reportedandcalculatedgrowthratesfromtheliterature

Calculatedgrow

thratesbasedon

informationprovidedinliterature

aApproximationsofmaximum

grow

thpotential(basedon

average13 maximum

sizesiffishreportedatharvest

21

13

General Information on Factors that Affect Fish Growth

Growth in fish is extremely variable and is impacted by many different

physiological and environmental factors Growth rates are known to change with size and

age sex season activity level density amount13 of living space quality and quantity of food

genetics and temperature (Brett 1979) Growth experiments conducted at different times

of year can result in growth rates that are not comparable As fish become larger their

physiological13 potential to grow decreases making determination of growth rate dependent

on the size of the starting fish and the length of the experiment (Busacker et al 1990)

Genetic factors also have great potential to influence growth rate Some species have

strains13 and13 races13 that display vastly different growth potentials (Reinitz et al 1979) All of

these factors combine to make assessment of the individual factors controlling fish growth

difficult13

Water temperature is probably the most important variable affecting growth rate13

All of the basic functions that affect growth such as feeding digestion and metabolism are

temperature-shy‐dependent13 Growth13 is inseparably13 tied13 to13 bioenergetics13 and13 therefore13 also13

tightly tied to temperature When temperatures are below optimum daily temperature

fluctuations can stimulate growth Photoperiod is also commonly linked to water

temperature and can influence growth rates in fish (reviewed in Brett 1979)

Fish density13 is known to13 affect growth13 and13 can alter13 growth13 rates13 in several ways13

Fish that exhibit strong territorial behaviors13 or natural schooling tendencies13 will

experience reduced growth if densities are too high or too low (Brett 1979) Dominance

hierarchies where some fish feed more aggressively than others can also lead to high

variability13 in growth13 rates13 (Koebele13 1985) Crowded13 conditions13 also13 cause physical

interference13 between13 fish and13 poor water13 quality13 which13 reduces13 growth13 (Busacker13 et al13

1990) The effects of fish numbers space and feeding opportunity are frequently correlated13

and often13 difficult13 to distinguish (Brett13 1979)13

It is impossible to study the effects of environmental factors on growth without also

evaluating feed rations (Brett 1979) Amount of food quality of the diet particle size

number of feedings per day and time of feeding have all been shown to affect growth

(Busacker et al 1990) In controlled laboratory studies food is usually fed ad libitum13

22

13

(constantly available) and other variables are altered to assess impacts of environmental

factors13 on growth13 These studies13 are13 usually13 conducted13 in tanks13 or raceways13 because13

researchers must verify that food is constantly available to the fish which is difficult to do

in large pond environments where the fish and the bottom13 are often not visible (Busacker13

et al13 1990)

Specific Information13 o Razorback13 Sucker13 Growth

Variable13 growth

Growth in razorback suckers is naturally highly variable and may be a function of

their evolutionary history (USFWS13 2002)13 Minckley (1983) speculated that13 wide size

variation in a single cohort of razorback suckers may be adaptive with fast-shy‐growing13 fish

that13 reproduce at a young13 age surviving13 better in13 high discharge years and slow-shy‐growing13

smaller fish surviving better during drought periods This highly variable growth rate

makes rearing razorback suckers in a production setting difficult because fish from13 a single

cohort do not reach the target stocking size simultaneously One of the major tasks for

aquaculture is to maximize both individual growth and total production13 (Gerking13 1978)13

This becomes more difficult when the species being cultured exhibits highly variable

growth13 rates13 because of genetic influences as is the case with razorback13 suckers13

Razorback13 sucker growth13 is typically very13 rapid13 during13 the first13 year of life13 and then13

declines with age First year growth can be as low as 50 mm and as high as 350 mm (Valdez

et al13 1982 Minckley13 1983 Mueller13 1995) Razorback sucker13 grow rapidly13 for

approximately the first five or six years of life and then growth slows13 (McCarthy13 and13

Minckely 198713 Tyus 199813 Minckley et13 al 1991)13 Growth of older individuals in13 extant13 wild

populations is very13 low (Minckley 198313 Tyus 198813 Modde13 et al 1996)13 Wild growth13 rates

for mature adult fish in Lake Mohave based on PIT tag recaptures were often too small to

be accurately measured for both males and females over the time period of 1987-shy‐199713

(Marsh and Pacey 1998) This information suggest it will take substantially longer to rear

fish to13 increasingly13 larger13 stocking13 sizes (40013 ndash 500 mm TL) than it did to reach the target

size of 300 mm TL

Growth in ponds

23

13

One of the main strategies for maintaining genetic refugia and self-shy‐sustaining13

populations of razorback13 sucker in the lower Colorado13 River basin13 is to rear razorback13

sucker13 larvae13 in production13 ponds until they13 are13 a suitable13 size for stocking13 (USFWS13 2004)

Pond culture has proven useful to promote rapid growth of juvenile razorback suckers

(Kaeding and Osmundson 1989) Marsh (1994) reported that growth rates of razorback

suckers13 reared13 in golf-shy‐course13 ponds exceeded13 the13 best growth13 rates13 obtained13 under

intensive13 culture13 conditions13 at federal hatcheries13 especially13 during the13 first several years13

of life Growth rates in these semi-shy‐natural ponds are also comparable to estimated growth

rates13 of juvenile13 wild13 fish (McCarthy13 and13 Minckley13 1987) Modde13 and13 Haines13 (2005)

reported13 the13 greatest growth13 rates13 in the13 largest and13 deepest floodplains13 with13 the13 greatest

amount of submergent vegetation but excellent growth and survival of fish in a grow-shy‐out

pond is of little value if there is not an efficient way to collect the fish from13 the pond

(Kaeding and Osmundson 1989)

Temperature13

Bulkley and Pimentel (1983) used shuttle boxes in the laboratory to determine a

temperature preference13 for razorback suckers13 of 23-shy‐24degC13 In13 their13 studies13 razorback

suckers were found to avoid temperatures below 118 degC or above 286 degC Razorback

suckers at Bubbling Ponds Hatchery are more active in the spring and feed better as

photoperiod increases even prior to water temperatures rising (Frank Agygos personal

communication) Table 3 briefly summarizes water temperature data from13 each facility

Detailed seasonal water temperature profiles are not currently available for many

razorback grow-shy‐out sites13

Density13

Extensive studies have been conducted on commercially important species to

evaluate stocking densities and feeding rates that maximize production For these species

controlled experiments under laboratory conditions have established relationships

between temperature density and feed ration on growth (Brett 1979) but this information

is sporadic13 or non-shy‐existent for razorback suckers13 (Bays13 et al13 2005) Fish culturists13 with13

24

13

experience13 rearing13 razorback suckers13 typically13 have13 target stocking13 densities13 that13 they use

(Tables13 4 -shy‐ 5) These stocking densities have largely been determined over time by trial

and error These approximate stocking densities provide a good starting point for more

controlled13 types13 of replicated13 pond studies13

Feed ration

Razorback13 suckers are currently13 being13 fed a wide variety13 of prepared diets (Table 7)

that range from13 a slow-shy‐sinking salmon feed manufactured by Silver Cupreg to a spirulina

and krill-shy‐enhanced catfish feed made by Rangenreg Most locations are feeding 20 ndash 50

body13 weight per13 day13 Methods13 for culture13 of razorback sucker13 larvae13 in intensive13 settings13 at

fish hatcheries are well documented (Figiel 2005) and various larval fish diets have been

evaluated13 (Tyus and13 Severson 1990 Severson et al13 1992) but no standardized13 procedures

are used for feeding13 larval13 fish in13 intensive settings13

Razorback sucker larvae are also effectively reared in pond environments using

natural foods supplemented with larval fish diets and survival is high when no predators

are present13 (Mueller 2006)13 Growth rates for larval13 and early juvenile razorback13 suckers

may increase with pond fertilization Diet and physiological studies on wild razorback

suckers indicate that they feed on plankton as well as benthic organisms during their entire

life (Marsh 1987) Artificially fertilizing ponds may greatly increase production capacity

and growth rates for razorback13 sucker (Papoulias and Minckley13 1992) and warrants

further13 investigation13

Handling stress

Handling stress13 has13 been shown to13 influence growth13 rates13 Paukert13 et al (2005)

found that growth of bonytail chub was reduced by 26when compared with controls

after being13 repeatedly13 captured and handled in13 hoop13 nets13 Handling13 effects are likely13 to be

similar for razorback suckers that are repeatedly13 captured and sorted in13 a hatchery13 setting13

Razorback suckers that are handled at Willow Beach National Fish Hatchery will commonly

not eat for two weeks after handling (John Scott personal communication) This creates a

difficult situation13 for production13 facilities because13 fish13 need to be sorted to ensure13 large13

25

13

aggressive fish do not interfere with growth of smaller individuals but frequent handling

and sorting13 causes stress related reductions in13 growth13

Measuring Growth in Captive Fish

Weight is the traditional measure used to estimate growth or production in

aquaculture settings13 Groups of fish are typically13 weighed and an average individual13 weight13

is computed (Busacker et al 1990) Although this method is often logistically the easiest it

may not be the most informative for species with highly variable growth rates like

razorback suckers especially when target lengths must be reached before fish can be

stocked Weight can also be highly influenced by things like stomach fullness or

development of gonads (Busacker et al 1990) Condition factor or relative weight can also

be used to assess growth of fish but these tools may be more robust predictors of fecundity

than of growth (Anderson and Neuman 1996) For some species sexes need to be

distinguished because males and females may differ in morphology (Anderson and

Neumann 1996) Mueller (2006) analyzed growth rates based on PIT tag recaptures of 86

razorback suckers13 in High13 Levee Pond13 and13 found13 that differences13 in growth13 do not appear13

to occur until fish are over 450 mm TL at which time growth rate in males slows while

females continue to grow at a slightly higher rate This would indicate that sex may not be

an important factor to consider when examining growth rates unless the target grow-shy‐out

size is above 450 mm TL

The best measures of growth are often determined from13 the length and weight of

individuals rather than from13 groups of fish (Anderson and Nuemannn 1996) because

individual growth rates give better estimates of confidence and variance (Busacker et13 al

1990) Length frequency analysis or recapture of previously marked individuals of a known

size is likely to yield the most useful information for razorback sucker growth The success

of any of these methods depends on proper sampling procedures that are representative of

the population as a whole (Busacker et al 1990) Sampling methods that are known to be

size-shy‐biased such as trammel nets (Mueller et al 2004) or cast nets should not be used when

trying to measure growth rates13

26

13

Conclusions

For razorback sucker survival is largely associated with stocking size Additional

focused13 research13 is therefore13 needed to13 identify13 ways13 to13 increase13 growth13 rates13 of captive-shy‐

reared13 razorback sucker Growth13 rate13 in fish is controlled13 by many factors including fish

size and age temperature density and feed ration which can all be highly correlated

Growth of razorback suckers is also inherently variable which makes the task of identifying

the key factors that13 affect13 growth in13 captivity even more difficult The focus at most

razorback rearing facilities13 is production so the13 types13 of data that are13 collected13 are13 often

insufficient for detailed13 evaluations13 of individual rearing13 practices13 on growth13 Surveys of

existing13 razorback sucker13 rearing facilities indicate that culture methods vary widely and

the types of growth data13 that13 are collected are not13 standardized13 Replicated studies with

detailed information on rearing location water temperature initial stocking size stocking

density and the sizes of all fish at harvest are needed in order to compare the effects of

individual rearing practices on growth This type of research will ultimately provide both

time and cost-shy‐savings to production facilities by reducing the amount of time necessary13 for

razorback sucker to reach stocking size improving overall production efficiency

Optimum13 rearing densities for razorback sucker larvae and juveniles remain to be

determined Current stocking densities will be very useful as starting point for more

detailed studies and although optimum13 rearing densities are likely to be site-shy‐specific13

replicated studies on density will provide a valuable reference for hatchery managers

Frequency13 of sorting is another13 area that needs13 further13 research Frequent

handling13 and13 sorting13 can13 cause13 stress-shy‐related13 reductions13 in growth but not sorting can

create dominance hierarchies that further reduce growth rates of subordinate individuals

The effects13 of sorting13 on overall fish growth13 in both13 pond and13 intensive13 culture13

environments warrant further investigation Research techniques for these types of

experiments are well understood and typically utilize a matrix of replicate ponds per

variable (Bays et al 2005) In every case accurate and complete records of sampling

procedures and data collection are needed in order to interpret data and make inferences

about13 growth rates (Busacker et13 al 1990)13

27

13

Additional research is also needed to evaluate long-shy‐term13 survival of stocked fish

reared in ponds compared to fish13 reared13 in intensive13 culture13 facilities13 Exercise13

conditioning13 and predator-shy‐recognition training may also increase survival of stocked fish

and be more economically feasible than rearing fish to increasingly larger sizes prior to

stocking13 The success13 of traditional fish hatchery programs is measured largely by the

number of fish stocked but hatchery programs for endangered species must measure

success in terms of long-shy‐term13 survival and species recovery (Brannon 1993 Anders 1998)

A specific list of research recommendations follows

Specific Research13 Recommendations13

bull Use replicated studies13 to establish optimum stocking13 densities13 for ponds13 and

tanks13 that can be used as13 a starting13 point for site specific refinement

bull Determine if sortinggrading13 improves13 overall growth rates13 in both ponds13 and

intensive culture facilities13

bull Investigate the use of artificial fertilizers13 to improve growth of both juvenile

and adult razorback suckers13 in ponds13

bull Determine if the razorback sucker diet gives13 better growth rates13 than cheaper

catfish or salmon feeds

bull Evaluate growth rates13 and production potential of new intensive culture

methods13 such as13 large circular tanks13

bull Evaluate13 long-shy‐term survival of fish produced from raceways13 and circular tanks13

compared to fish reared in ponds13

bull Evaluate more effective means13 of treating13 fish diseases13

bull Evaluate factors13 other than size that may increase post-shy‐stocking13 survival such

as13 exercise conditioning13 predator recognition training or rearing13 under more

natural settings13

28

13

II The Effect of Disease Treatments on Razorback Sucker

Growth

Section13 SummaryFormalin copper sulfate potassium permanganate and13 salt are all chemicals commonly13 used13 to13 treat13 Ichthyophthirius multifiliis outbreaks in captive razorback sucker (Xyrauchen13 texanus) Weexposed 190 juvenile13 razorback suckers (127 ndash 26 mm TL) to13 5 5-shy‐day treatments with13 each13 chemical to evaluate the effects13 these chemicals13 may have on growth Fish grew an average of23513 mm TL13 during the month13 study period Fish treated with formalin grew on average13 29mm TL (03 mmday) while fish treated with copper had the lowest growth averaging 20 mmTL (021 mmday) No significant differences in13 growth were observed among fish treatedwith any of the chemicals compared to untreated fish (pgt005) Reductions in growth13 as aresult of repeated chemical treatments are not likely the cause of differences in growth ratesamong13 facilities that raise razorback suckers Repeated chemical treatments may13 have otherimpacts to overall13 fitness or long-shy‐term survival but13 these effects were not13 evident13 in our study

29

13

Introduction

Preservation13 of razorback sucker13 (Xyrauchen texanus) currently13 depends on captive13

rearing and stocking programs until permanent solutions to factors that prevent wild13

recruitment are found Low survival of stocked razorback suckers (Brooks 1986 Marsh

and Brooks 198913 Marsh and Pacey13 2005) has caused target13 sizes for stocked fish to

steadily increase in efforts to reduce predation mortality (Marsh et al 2005 Schooley and

Marsh 2007) Rearing fish to larger sizes at hatcheries comes with increased costs and

creates the need to evaluate husbandry and rearing practices that may affect fish growth

Formalin copper sulfate potassium13 permanganate and salt are all chemicals

commonly used at razorback sucker rearing facilities to treat outbreaks of the protozoan

parasite13 Ichthyophthirius multifiliis ldquoIchrdquo is one of the most pathenogenic diseases of

cultured13 freshwater13 fishes (Matthews13 2005) and causes large13 losses in captive13 populations13

of endangered razorback sucker Each of these chemicals used to treat Ich only kill the free-shy‐

swimming life stage of the parasite13 requiring13 repeated doses over several13 days depending13

on water temperature These chemicals treatments are needed to prevent loss as a result

of disease outbreaks but the cumulative effects repeated disease treatments have on

growth13 are13 unknown

Copper13 sulfate13 has13 been shown to13 significantly13 reduce13 growth13 of channel catfish13 in

production13 ponds (Rabago-shy‐Castro13 2006) but it is unknown whether13 razorback suckers13

experience similar reduced growth following copper treatment Quantifying the impacts of

disease treatments on growth will help to interpret the wide differences in growth rates

observed13 at various13 razorback sucker13 production13 facilities13 throughout the13 southwest

(Ward et al 2007) If one chemical is found to have less detrimental impacts on growth

than another then it may be preferred for use as a disease treatment We evaluated growth

rates13 of razorback suckers13 under13 replicated13 and13 controlled13 conditions13 to13 assess13 effects13 of

repeated formalin copper sulfate and potassium permanganate and salt treatments on

growth13

Methods

We captured 190 juvenile razorback suckers from13 ponds at Bubbling Ponds Fish

Hatchery AZ using hoop nets or cast nets All fish were of the same age class and

30

13

averaged 179 mm total length (TL) (range13 = 127 ndash 262 mm TL)13 These fish were13 offspring13

of captive13 razorback sucker13 broodstock held13 at Dexter13 National13 Fish Hatchery13 NM13 (2007

year class) All fish were tagged with passive integrated transponder (PIT) tags and

quarantined for one month prior to the experiment to allow fish to recover from13 tagging

and become accustomed to being held in circular tanks

At the beginning of the study all fish were weighed measured and scanned for

individual tag numbers with 19 randomly selected fish placed into each13 of 10 8-shy‐foot

diameter circular tanks (Figure 2)13 Each13 tank contained13 two13 airstones13 and13 an13 individual

biofilter with a recirculating water pump (31 litersminute) that had been operating for

at least 1 month prior to the experiment to allow bacterial colonies to become

established Two tanks were designated as a control and did not receive any chemical

treatments while the other eight tanks received formalin copper sulfate potassium13

permanganate or salt treatments at two week intervals (two tanks per chemical

treatment) Formalin copper sulfate and potassium13 permanganate were treated at 1 part

per million (ppm) and salt was applied at 30 parts per thousand (ppt) These treatment

rates are commonly used to treat13 razorback13 suckers for ich at Bubbling13 Ponds Fish13

hatchery (Frank Agygos personal communication)

Figure 213 Photo ofexperimental tankswith individualbiofilters and aeration

31

13

Each treatment consisted of a series of doses applied on Wednesday Thursday and

Friday with a 90water change between each dose Biofilters were removed from13 all

tanks and held in a separate holding facility during treatments and then replaced on the

Monday following treatments after a 90water change This schedule allowed fish to be

exposed to chemical treatments for 5 consecutive days without water quality deteriorating

This 5-shy‐day chemical treatment was repeated every two weeks from13 July to October (97

days)13 for a total of 5 5-shy‐day treatments Water temperature in the treatment tanks ranged

from13 13degC (55degF) to 32degC (91degF)

Fish were fed a fixed ration of commercial razorback diet (Silvercup 4mm13 pellet)

once daily13 (2 percent body13 weight per day13 as calculated13 by13 average initial fish weight)13

At the end of the experiment all fish were again weighed measured and scanned for

individual tag numbers Growth of fish in each treatment group was compared using

analysis of variance (ANOVA) Any mortalities13 that occurred during the13 study13 were13

replaced with previously quarantined fish of equivalent size to maintain equal densities in

each13 tank13 but growth13 data was13 only13 recorded for fish which13 survived13 the13 entire13

experiment

Results

Fish at the13 start of the experiment averaged 179 mm TL (Range13 = 127 ndash 262 mm)

with no significant differences in fish length among treatment groups (F(4189) = 00183 p

gt 0999 ANOVA) On average fish grew 235 mm TL (024 mmday) during the 3 month

study13 Fish in tanks13 treated with formalin had the highest growth averaging 29 mm TL (03

mmday) while fish in tanks treated with copper had the lowest growth averaging 20 mm

TL (021 mmday) Fish in the control tanks averaged 213 mm TL in growth (022

mmday) (Figure13 3)13 Formalin-shy‐treated fish grew13 significantly faster than13 any other

treatment group but no13 significant differences in growth13 in length13 or weight were13

observed among fish treated with any of the chemicals compared to untreated (control)

fish (pgt005 ANOVA)

32

13

Figure 313 Average growthof razorback suckersexposed to a series of 5 5-shy‐day chemical treatmentsover a 97-shy‐day13 periodError bars representstandard error

Discussion13

Growth13 rates13 observed13 in our study13 (021 ndash 03 mmday) are low compared to those

reported13 in other13 studies13 of razorback sucker13 growth13 (0213 ndash 18 mmday) (Ward et al

2007) Using recirculating water systems for our study required filters to be removed and

replaced during treatments Stress to fish caused by removing and replacing filters within

the tanks as well as repeated water changes may have led to overall higher stress and

reduced growth rates compared to those reported for unconfined fish Growth in fish is

highly variable and is affected by many different physiological and environmental factors

including fish size density temperature amount of space and food (Brett 1979) We

strived to control each of these factors but other factors may have also influenced growth

in our experimental tanks During mid-shy‐summer water temperatures in the treatment

tanks reached 32degC (91degF) At these warm13 temperatures fish are very susceptible to

bacterial13 infections13 The slightly higher growth exhibited by fish in the formalin and

potassium13 permanganate treatments may have been the result of these two chemicals

33

13

being effective at controlling bacterial infections The differences in growth we measured

among treatment groups were not statistically significant and do not appear13 biologically13

meaningful during the relatively short duration of this study (97 days) although the

cumulative effects of slightly reduced growth could be biologically meaningful over longer

time frames

Reductions in growth13 as a result13 o repeated chemical treatments are not likely the

cause of differences in growth rates among facilities that raise razorback suckers

Repeated chemical treatments may have other impacts to overall fitness or long-shy‐term13

survival but these13 effects13 were13 not evident in our study It is more likely that the parasite

outbreaks themselves are the cause of different growth rates among razorback rearing

facilities rather than the chemical treatments used to treat the parasites We recommend

that hatchery managers continue to use the chemicals that are most effective at controlling

ldquoIchrdquo13 at their individual13 facilities

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower Colorado Rive Multi-shy‐species13

Conservation Plan under Work Task C10 We thank Ty Wolters and Tom13 Burke for their

support of this research and Frank Agygos and Dave Billingsly of the Bubbling Ponds Fish

Hatchery13 for their13 technical assistance13 and13 help with13 collecting13 fish

34

13

III13 Razorback Growth Rates at Bubbling Ponds ndash 2009-shy‐2011

Section13 SummaryExperimental studies at Bubbling Ponds Fish Hatchery AZ have strived to understand

factors that affect razorback sucker growth in captivity and identify ways to improve growthrates and maximize size at release Rather than performing experimental studies that wouldrequire major13 rearrangement (and likely reduced production)13 of hatchery operations our13 studies13 used normal variation in production techniques13 and practices13 to isolate factors13 thatmay modify growth rates

Our initial work identified razorback13 growth rates in13 lined ponds at standard fishdensity as 026 to13 028mmday (789 to 843 mmmonth) No significant differences in growthrate were observed among fish that had been in the pond only during the winter13 periodcompared to fish that had been in the pond the entire year indicating that water temperatures13 at Bubbling Ponds are high enough to allow fish to incorporate feed effectively year-shy‐roundHowever these growth rates are lower than most values reported from the literature fromnatural or semi-shy‐natural pond environments No significant differences in13 growth rate wereobserved13 between large and13 small fish13 within the 150 ndash 29 mm TL13 size range Additional worksuggests13 that razorback suckers13 tagged at over 300 mm TL had reduced growth rates (024mmday 73 mmmonth) as would be expected according to a typical Von13 Bertalanfy growthcurve although growth rates13 were only slightly less13 than the average growth rate for thehatchery (027513 mmday 82513 mmmonth)

Sorting13 to13 separate small fish from large fish after the first year of growth is practicedesigned13 to allow smaller fish to ldquocatch uprdquo to larger fish We found that13 this technique doesappear to13 improve growth rates of smaller fish Growth rates of sorted small razorback suckers(029 mmday 87mmmonth)13 were equal to that13 of larger13 fish (028 mmday 8413 mmmonth)indicating that sorting may have helped to offset their original slower growth trajectory

Bubbling Ponds Fish Hatchery grows razorbacks in 6 long deep ponds lined with heavyplastic 2 long deep13 earthen13 (unlined) ponds and three wide shallow earthen ponds The wideshallow ponds13 have historically produced very large fish at low density but have been found tomaintain much lower fish numbers than deeper ponds We found13 that growth13 rates ofrazorbacks kept at high density (4-shy‐700013 fish)13 in a wide shallow pond grew extremely slowly(024 mmday 726 mmmonth) This growth rate is among the slowest of any fish over theyears of our study and demonstrates that13 though the large ponds may produce large fish at lowdensity13 they are unable to overcome high13 fish13 densities

Finally one of the major factors influencing13 fish13 growth13 in hatcheries is disease onemajor summer-shy‐time disease at13 Bubbling Ponds is the ectoparasite Ich (Ichthiopthirusmultifiliis) To investigate the impact Ich has on razorback growth we eradicated fish from thespring and water conveyance ditch that supplies13 water to the hatchery using Rotenone This13 restoration effort was fairly short-shy‐lived (Ich returned to the hatchery within four months) but

35

13

growth13 rates of fish13 reared for four months without Ich present (031 mmday 92 mmmonth)were significantly higher than the following 8 months of growth for those same fish (022mmday 65 mmmonth) This disease-shy‐free growth rate is in fact faster than any13 otherprevious growth rates observed at the hatchery in our study

We conclude that growth rates at the Bubbling Ponds Fish Hatchery are likely as highas possible given the pond densities required to13 meet production goals and the Ich-shy‐infestedwater13 that feeds the facility Sorting practices are successful in helping as many fish as possiblereach stocking length as fast as possible Unlined ponds may be able to grow large fish at lowdensities but whatever factors allow for that growth13 are not able13 to overcome13 high fish densityThus the large lower ponds at Bubbling Ponds may be better utilized via renovation to13 deepenand line them

Disease is the most important factor limiting growth as may be expected to be the caseat many13 hatcheries While the spring renovation was not13 a complete success13 the dramaticreduction of fish populations in that habitat was enough to dramatically13 reduce13 the13 occurrenceof Ich at the hatchery13 Such open spring13 systems feeding a hatchery are a misfortune that canbe expected to transmit disease so we suggest that renovating the spring again to combat13 IchImproved techniques to divert water from13 the springs and more throuough treatment ofstream-shy‐side vegetation may improve the success of chemical treatment Successful renovationwould likely both improve growth rates and reduce chemical costs associated with treating Ichoutbreaks Even13 if complete renovation13 is impossible or impractical an13 effort to reduceinvasive fish density in the springs13 which act a vector for the parasite(and thereby reduce thelikelihood of13 Ich being transmitted into ponds) may still13 show dramatic improvements

36

13

Introduction

Conservation efforts13 for razorback sucker13 (Xyrauchen texanus)13 currently13 depend on

captive rearing and stocking programs Low survival of stocked razorback suckers (Brooks

1986 Marsh13 and13 Brooks13 1989 Marsh13 and13 Pacey13 2005) has13 caused13 target sizes for stocked13

fish to steadily increase in efforts to reduce predation mortality13 (Marsh13 et al13 2005

Schooley and Marsh 2007) Rearing fish to larger sizes at hatcheries comes with increased

costs and creates the need to evaluate husbandry and rearing practices that may affect fish

growth13 We evaluated growth13 rates13 of individual razorback suckers13 in ponds13 at Bubbling

Ponds Fish Hatchery13 using Passive Integrated13 Transponder (PIT) tags13 to13 obtain13 precise

growth information for individual fish so that valid comparisons of growth rates as related

to rearing practices can be made

Due to the critical nature of the razorback sucker stocking program we did not

design experimental studies that would require major rearrangement and potentially

reduce production of hatchery operations Instead our studies used normal variation in

production techniques and practices to isolate factors that may modify growth rates

Though this methodology dramatically limits replication and may limit our ability to

directly13 attribute13 differences in growth13 rates13 to13 the13 variables13 we13 investigate13 we13 were13 able13

to accomplish research goals without altering hatchery operations or impacting

production

From13 2009 through 2011 we conducted a series of observational13 growth13 studies to

determine growth rates of individual razorbacks at Bubbling Ponds The first set of

experiments included13 identifying13 growth13 rates13 in lined13 and13 unlined13 ponds determining

growth13 rates13 of fish at different13 sizes13 in13 relation13 to sorting13 practices and monitoring

razorback growth rates after removing the source of the ectoparasite13 Ich (Ichthiopthirus

multifiliis) from13 the hatchery water source13

Razorback growth rate in lined ponds

Our first growth study documented individual growth rates at normal density in 11

million gallon lined ponds13 over two13 years13 This is the standard13 grow-shy‐out process for

razorbacks13 at Bubbling Ponds We monitored growth of fish for a variety13 of sizes and13 the13

37

13

amount of time in a pond during the growing season These13 data give a snapshot of growth13

rates13 at the13 facility13 and13 provide13 the basis for comparisons throughout our study

Growth rate13 in an unlined pond

In addition13 to 6 ponds lined with heavy plastic13 sheeting13 Bubbling Ponds Fish13

Hatchery maintains two narrow and deep (same dimensions as lined ponds13 Figure13 4)13 and13

three large13 shallow unlined ponds These earthen13 ponds typically have vegetation and

associated aquatic invertebrates that may better simulate natural environments by

providing cover and improved food diversity or quality Therefore these unlined ponds

may be expected to produce higher growth rates and potentially improved survival that is

more similar to growth rates observed in more natural grow-shy‐out facilities13 Historically13 the13

large13 shallow13 ponds have produced very large fish when13 utilized at low13 fish density13 The

narrow13 deep earthen13 ponds are13 used to grow13 fry13 at high density in their first13 year of life

The major downside to unlined ponds is the difficulty in harvesting fish where a lined

pond might take 8-shy‐1013 people13 a half13 day13 to13 harvest13 lined13 ponds13 require13 intensive13 weeding13

to allow seines to be pulled and therefore require many more personnel-shy‐hours13 In addition13

to harvest challenges the shallow earthen ponds tend to suffer from13 dissolved oxygen

crashes during the summer Unlined ponds also may maintain higher13 populations13 of non-shy‐

target species such as bluegill sunfish mosquito fish and bullfrog tadpoles We measured

growth rates of suckers in a large shallow earthen pond for comparison to growth in lined

ponds13

Figure13 4 Lined13 and13 earthen ponds13 of similar dimensions (approx 1000000 gallons first

and second panels) and a large13 shallow13 earthen13 pond (third panel)

38

13

Effect of sorting on growth

Razorback13 suckers13 are13 currently13 sorted13 after their first13 year of growth13 They are13

typically removed from13 one of the13 upper earthen13 ponds and13 split into13 two13 lined13 ponds for

subsequent grow-shy‐out13 The larger13 fish (gt approximately 140 mm) are placed into one pond

and the smaller individuals in another It is possible that the larger fish were more

aggressive or adept13 at taking food so this sorting process is intended to allow smaller fish

to improve their growth rate

Effect of Ich on razorback sucker growth rates

We13 evaluated13 growth13 rates13 of razorback sucker13 in the13 presence13 and absence of the

ectoparasite13 Ich (Ichthiopthirus multifiliis) Ich outbreaks can occur in wild populations13 but

hatcheries13 have13 proven excellent locations13 for Ich because13 of very high fish densities13 which13

facilitate13 the13 transfer13 of Ich13 between13 fish This common fish parasite causes direct mortality13

to razorback13 suckers as well13 as secondary bacterial13 infections13

The open spring and13 ditch13 which13 provides water to the Bubbling13 Ponds Hatchery

has long13 been infested with mosquitofish (Gambusia affinis) that harbor13 the13 Ich parasite13

and allow13 it13 to enter the hatchery with incoming13 water13 The solution13 to13 the13 Ich problem13

was to remove the mosquitofish host using13 Rotenone Razorback13 sucker growth13 rates were13

then tracked in13 the absence of this parasite for 4 months and compared with growth rates

after Ich returned to the pond and from13 previous years

Methods

Razorback growth rate in lined ponds

On May 14 2008 141 razorback suckers were tagged with 12 mm PIT tags (1342

kHz) and placed in Pond 3 (approximately 1100000 gallons13 Figure13 4)13 at Bubbling13 Ponds

Fish Hatchery Fifty-shy‐three of these tags were recovered two months later when a large

Ichthyophthirius multifilis (Ich) outbreak killed many fish in the pond On October 15 2008

an additional13 145 PIT tagged13 fish were13 also placed into Pond13 3 On13 May13 14 2009 Pond13 3

was harvested and a total13 of 141 PIT tagged fish were recovered13 Of the tagged fish13 26 fish

had13 been13 in the13 pond since May13 of 2008 (378 days13 o growth) and 115 had been13 in13 the

39

13 40

pond since October13 15 2008 (211 days13 of growth) Numbers of fish in Pond 3 after the Ich

outbreak and for the majority of the period of growth were between 3 000 and 4000 fish

A Hobotempreg temperature13 logger13 was13 also13 installed13 in Pond 3 one meter below the water

surface13 near13 the13 outflow and13 recorded water temperature every 3 hours to allow analysis

of the effects of water temperature on growth rate (Figure13 5) This Hobotemp data is

representative of other pond temperatures throughout this study

In a second experiment 210 adult13 razorback suckers13 were13 PIT tagged13 on13 May 14

2009 and13 placed13 into13 Pond13 3 upper to13 evaluate13 growth13 rates13 of larger13 razorback suckers13 at

Bubbling13 Ponds Hatchery13 under current13 rearing13 conditions13 Size of these fish at tagging13

was (mean = 285 mm range = 205 ndash 396 mm) These fish remained in the pond for 257

days and were harvested on Jan 25 2010 to provide information on growth rates of larger

razorback suckers13 under13 current rearing conditions

Figure 513 Temperatures (degC) inrearing pond at BubblingPonds Hatchery from July toSept 2009 (top graph)13 andfrom Nov to Dec 2009 (Lowergraph) Temperaturesrecorded with a Hobotempregremote data logger13 every 3hours

13

Growth rate13 in an unlined pond

To document razorback sucker growth in earthen ponds we introduced13 225 tagged13

razorback suckers13 into13 Pond13 1 lower13 (Figure 4) in February 3 2010 Additional tagged fish

from13 other studies were added to the pond throughout the growing season and the density

of 1 lower reached a maximum13 of nearly 7000 fish in early summer 2010 Density was

reduced to approximately 6000 fish by capturing fish with hoop nets on June 3 2010 54 of

these fish were tagged fish and returned to 1 lower after being weighed and measured The

pond was harvested on January13 2713 2011 and a total13 of 254 tagged fish out13 of 4296 fish

total were removed from13 the pond The pond was harvested on January 27 2011 (358 days13

of growth) and the tagged fish were weighed and measured Total number of razorbacks in

the pond at harvest13 was 4296

Effect of sorting practices on growth rates

On March 1113 200913 Pond13 5 upper was13 harvested13 and13 split into13 two13 separate13 groups

Two hundred of the smaller fish (average size = 122 mm TL) were PIT tagged and placed

into13 Pond13 7 upper and13 200 of the13 larger13 fish (average = 160 mm TL) were PIT tagged and

placed int Pond13 8 upper Density13 in Pond13 7 was13 4500 fish and13 in Pond13 8 there13 were13 6500

fish These ponds were then harvested after 1 year and growth rates were compared to

give information on the effects of current sorting practices Hobotempreg temperature

loggers were installed in13 Ponds 7 and13 8 during13 the13 grow-shy‐out period with13 water13

temperature recorded every 2 hours13 (Figure13 6)

Effect of Ich on razorback sucker growth rates

Bubbling Ponds spring was treated with Rotenone (CFT Legumine 5) at a

concentration of 2 ppm13 to remove all mosquitofish from13 the spring The treatment

consisted of two treatments 6 hours in duration on two consecutive days (April 12 -shy‐ 13)

using13 drip13 stations13 and13 backpack sprayers13 followed13 by13 an13 additional 6 hours13 of

detoxification using sodium13 permanganate Although 12 mosquitofish were captured in the

spring pond the week following the treatments subsequent minnow trapping (20 traps

checked13 daily13 for 3 weeks) did not capture any additional fish until August 11 2010 when

41

13

juvenile mosquitofish were again detected in the spring pond Minnow traps have

subsequently been set daily with several hundred individuals removed To evaluate if Ich

was also again present in the spring we captured 15 mosquitofish from13 the spring pond on

three separate days and placed them13 in an aquaria at 25 degC with 5 longfin dace known to be

free of Ich These fish were monitored for 2 weeks with no signs of Ich developing This

indicates that even though mosquitofish have returned to the spring pond the parasite is no

longer present13 although how13 long13 this condition13 will13 persist13 is unknown13

On May 1113 201013 200 juvenile razorback13 suckers were harvested out13 of Pond 5

upper (2009 year Class from13 Dexter National Fish Hatchery) and were PIT tagged and

placed into Pond 8 to evaluate if growth rates at bubbling ponds hatchery have improved

following the renovation of the spring and the removal of the Ich parasite Unfortunately13

on Sept13 8 2010 Ich was13 again13 detected13 in Pond 8 and the pond was immediately seined

and 74 tagged fish were measured to obtain growth information for the 4-shy‐month period

during13 which13 the13 pond13 was13 Ich-shy‐free13

Figure13 6 Temperatures (degC) in rearingponds 7 and 8 at Bubbling Ponds Hatchery13 from March 2009 ndash March 201013 pond 7(top13 graph)13 and13 pond 8 (Lower13 graph)13 Temperatures recorded with a Hobotempregremote data logger every 3 hours

42

13

Results

Growth in Lined Ponds

Razorback suckers13 that had been13 in13 Pond 8 upper for the13 entire13 year13 grew an13

average of 0263 mmday (789 mmmonth) and razorback suckers that had been in the

pond for 7 months (Oct -shy‐ May) grew13 on13 average of 028 mmday (843 mmmonth) (Figure13

7) These growth13 rates13 did not significantly13 differ Fish density13 in Pond 3 during13 the13

majority of the growth period was13 00032 ndash 00036 fishgallon13 Additionally no13 significant

differences in growth rate were observed between fish smaller than 210 mm TL and fish

larger than 210 mm TL when all recaptured fish were combined

We also measured the growth rate of very large fish in a lined pond On Jan13 2513 201013

156 adult fish with PIT tags were recovered from13 Pond 3 upper13 These fish were13 in the13

pond for 257 days and experienced an average13 growth13 rate13 of 024mmday or 73

mmmonth (Figure13 7)13 This growth13 rate13 is slightly13 lower13 than13 the13 average13 growth13 rate13

observed13 at Bubbling13 Ponds Hatchery in other studies (0275 mmday 825 mmmonth)

but may not be biologically meaningful We would expect larger13 fish to13 have13 reduced

growth rates according to a typical Von Bertalanfy growth model (Bertalanffy 1957) but it

appears that13 over the size range we evaluated (300 -shy‐ 450 mm TL) growth rates have not

slowed significantly compared to that of smaller13 fish grown at Bubbling Ponds13 Hatchery

Growth13 of razorback suckers13 is known13 to13 slow as13 fish reach13 larger13 sizes but it appears13 this13

reduced growth rate may not really start to be biologically meaningful at Bubbling Ponds

Hatchery13 until razorback suckers13 exceed 450 mm TL

Growth in unlined ponds

Growth13 rates13 for the13 fish recaptured13 during13 the Pond 1 lower13 thinning13 (120 days13 in

the pond) was 024 plusmn 003 mmday (729 plusmn 090 mmmonth) (Figure13 8)13 Fish13 that were13 in

the pond for nearly the entire year grew13 an13 average13 of 024 plusmn 001 mmday (726 plusmn 027

mmmonth) These growth rates are surprisingly the lowest measured growth rates for

any part of our study and differ significantly from13 every other measured growth rate

except very large13 fish (Figure13 9)13 Separating13 out13 large fish that13 were in13 the pond for the

entire year makes no difference fish that were added to the pond at TL lt300 mm grew

43

13

Gro

wth

Rat

e (m

md

ay)

020

026

032

0244 plusmn 001 mmday (733 plusmn 028 mmmonth) and and those with TL gt= 300 mm at the

start of the experiment grew 022 plusmn 003 mmday (651 plusmn 101 mmmonth)

Razorback Growth Rates in Lined Ponds

Figure 7 Growth ofrazorback suckers in(mmday plusmn standard error)in Pond 8 upper in 2008-shy‐2009 An ANOVA did notdetect any significantdifferences

7 Months Full Year 300+ mm fish

Effects of sorting on growth

One hundred and seventy five tagged razorback suckers were recovered from13 Pond

8 upper13 on March13 24 2010 (378 days13 of growth)13 These were13 the13 larger sorted13 fish (gt140

mm TL) that came out of Pond13 5 on March13 11 2009 One13 hundred and13 twenty13 two13 tagged13

razorback suckers were also recovered from13 Pond13 7 upper on March13 31 2010 (385 days13 of

growth)13 These were13 the13 smaller sorted13 fish (lt140 mm TL) that came out of Pond13 5 on

March 1113 200913 No significant differences in growth rate (mmday) were observed among

larger fish in Pond 8 and smaller fish in Pond 7 (pgt005 ANOVA) (Figure 10)13 indicating

that13 sorting may have helped to offset the original slower growth trajectory of the smaller

fish Temperatures of Ponds 7 and 8 upper remained similar throughout the year13 (Figure

5)

44

13

13

13

Gro

wth

Rat

e (m

md

ay)

Gro

wth

Rat

e (m

md

ay)

020

026

032

020

026

032

Razorback Growth in an Unlined Pond

Figure 8 Growth of razorbacksuckers (mmday plusmn standard error) in Pond 1 lower (an unlined pond)in 2010-shy‐2011 An ANOVA did notdetect any significant differences

6 Months 12 Months lt 300 mm Fish 300+ mm Fish Growth Growth

Lined vs Earthen Ponds 1 year of growth

Figure 9 Growth of razorbacksuckers (mmday plusmn standard error) in lined and unlined ponds A t-shy‐test13 did not detect a significantdifference

Lined Pond Unlined Pond 1 Yr Growth 1 Yr Growth

45

13

Effect of Sorting G

row

th R

ate

(mm

day

) G

row

th R

ate

(mm

day

)

032

020

026

032

020

026

Smaller Fish Larger Fish

Effect of Ich

Figure 10 Average growthof razorback suckers(mmday plusmn standard error)that were size-shy‐sorted intosmall fish (pond 7) and largefish (pond 8) populations At-shy‐test did not detect asignificant difference

Figure 11 Average growth ofrazorback suckers (mmday plusmnstandard error) after Ich wasremovd from the hatcheryrsquos springand after Ich was again detected inthe pond The growth rate withoutIch is significantly higher than boththe rate after Ich and the ourstudyrsquos average annual growth ratein lined ponds (ANOVA p =00003)

Growth without Ich Growth With Ich Average Annual 4 months 4 months Growth Rate

46

13

Effect of Ich on razorback sucker growth rates

Seventy-shy‐four13 tagged13 razorback suckers13 were13 recovered from13 Pond 8 on September

15 2010 These fish had13 been13 in the pond for 4 months and experienced a growth rate of

032 mmday or 97 mmmonth (Figure13 11)13 This growth13 rate13 is significantly higher (p =

005 two sample t-shy‐test) than the mean growth rate for the same group13 of tagged fish after

Ich detection (022 mmday or 65 mmmonth) and significantly higher than any other

individual growth13 rates13 observed13 to13 date13 at Bubbling13 Ponds Hatchery13 (Figure13 11)13 If this13

growth13 rate13 were13 extended throughout13 the entire13 year13 fish on average from13 Ich-shy‐free13 ponds13

would be 16 mm longer than fish from13 ponds infested with Ich Studies conducted at

Bubbling Ponds hatchery in 2008 (Ward 2008) did not reveal any effects of the treatment

chemicals on razorback sucker growth rates so it13 is likely that13 the parasite outbreaks

themselves are causing reducing growth rates rather than the chemicals used to treat the

parasites13

Conclusions

Our results suggest that under typical hatchery operations (maximizing number of

fish produced)13 the growth13 rate13 of razorback13 suckers13 is relatively13 consistent at Bubbling13

Ponds hatchery13 at 02-shy‐03 mmday (6-shy‐9 mmmonth)13 but is lower than growth13 rates13 at

other13 facilities (02 ndash 18 mmday Ward et al 2007)13 This growth13 rate13 has13 been13 constant in

both lined and unlined ponds and at all fish densities we were able to measure To achieve13

growth13 rates13 substantially higher than this will likely require13 significant changes in rearing

practices that may not be practical in order to reach numerical production13 goals

Temperature is a key variable in fish growth but seasonal growth patterns

described13 above13 (Figure13 5) demonstrate that water temperatures are high enough in

winter to maintain razorback growth Differences in water temperature by season

currently13 do not fluctuate more than 10degC at Bubbling Ponds because of the continuous

supply of water flowing through each pond (approx 225 gallonsmin) These high water

flows appear to keep pond temperatures within the thermal preference13 for razorback

suckers13 (1213 -shy‐ 28 degC Bulkley and Pimentel 1983) throughout the entire year with

temperatures rarely dropping13 below 16deg13 C (Figures 513 6)13

47

13

Fish density is another key variable in fish growth and though the number of fish in

a pond during our study ranged from13 3000 to 700013 fish we13 did not find any13 correlation13

between13 density and growth rate13 This might yield two conclusions First13 razorback

growth13 may be changed equally13 by13 densities13 at the13 hatchery13 (ie13 a density13 of 3000 fish in a

pond is as stressful13 for razorbacks as a density13 of 7000 fish) An alternative is that other

factors13 such as disease outbreaks have13 stronger13 control over fish growth13 than13 density13

Fish density13 would13 have13 to13 be13 experimentally manipulated to test13 this13 and hatchery

operations (producing the maximum13 number of fish) prevented our manipulating density13

in ponds for this13 work The trouble with manipulating density demonstrates the difficulties

associated with changing13 hatchery13 practices experimenting with density would have

prevented BPH from13 meeting13 production13 goals Given that the stocking of smaller

razorbacks has met with very little success perhaps BPH goals could be changed from13

producing 12000 fish at 300+ mm per year to a smaller number of very large fish each

year Growing13 fewer13 larger13 fish could potentially be accomplished in the same time frame

as more smaller fish but a better understanding of how density alters growth rate would

be required to be confident13 of this

The very slow growth13 in the13 earthen13 unlined13 Pond 1 lower13 was very surprising We13

had13 anticipated13 that the13 diversified diet13 cover and13 other13 habitat features13 provided by13

unlined ponds would yield dramatically increased growth rates However these traits were

not enough to offset high fish densities and in fact the unlined pond in our study13 suffered

mortality to bring densities down to that observed normally in lined ponds

Our data13 suggest13 that razorbacks13 sucker13 growth13 rates13 are13 higher in lined13 ponds13

However we13 think the reasons13 for the13 very slow growth we observed13 in the13 unlined13 pond13

in our study13 is instead13 linked13 to13 the13 usage13 of Pond 1 lower13 during13 the13 study13 rather13 than13

intrinsic13 slow growth13 in earthen13 ponds First the pond was at extremely high density for at

least part of the study The volume of Pond 1 lower has not been estimated but hatchery

managers suggest 1500-shy‐2000 fish is an appropriate number of individuals so this pond

was at a very high density for much of the experiment Second dissolved oxygen is often

very low in the13 large13 earthen13 ponds during the heat of summer much lower than that of

lined ponds This will both limit the number of fish that can survive in the pond and almost

certainly13 increases stress13 of these13 fish potentially13 reducing growth13 The DO crashes also13

48

13

limit the amount of feed hatchery managers can give fish in these ponds sometimes for

days or weeks at a time which further reduces growth during warm13 weather

Our data13 suggests that13 growth rates at the Bubbling13 Ponds Fish Hatchery are likely

as high as possible given13 the pond densities required to meet production goals and the Ich-shy‐

infested water that feeds the facility Sorting practices are successful in helping as many

fish as possible reach stocking length as fast as possible Unlined ponds may be able to

grow13 large13 fish at low13 densities13 but whatever factors allow13 for that13 growth are not13 able to

overcome high fish density The removal of invasive13 fis that act as13 a host for the13 parasite13

Ich fish from13 the Bubbling13 Ponds spring13 allowed the highest13 growth rate at 032 mmday13

(96 mmmonth) but that growth rate decreased again as Ich re-shy‐infested13 the13 hatchery13

Consistently13 achieving13 growth13 rates13 as high or substantially13 higher than13 this13 will likely13

require13 significant changes in rearing practices that may not be practical in order to13 reach13

numerical production13 goals

Two major changes that might result in higher growth rates are substantially

reducing fish density and modifying the way spring water is delivered to the facility (via

either repeated chemical treatments or enclosed concrete water diversions) to eliminate

Ich from13 the hatchery source water Other potential changes not address by our work

include13 flow-shy‐training razorbacks much previous literature including MSCP-shy‐funded13 work

on razorback suckers13 suggests13 that fish growing13 in flowing water will grow13 faster than fish

in still water (Jorgensen and Jobling 1994) Furthermore there are a wide variety of

potential benefits associated with growing13 fish13 in flowing13 water in addition13 to increased

growth13 rates13 (Davidson13 199713 Castro13 et al13 2011) Another option13 for increasing13 growth13

rates13 include13 changing to13 intensive13 culture13 in large circular13 tanks

Finally given that the stocking of smaller razorbacks has met with very little

success13 perhaps13 BPH13 goals13 could13 be13 changed from13 producing 12000 fish at 300+ mm per

year to a smaller number of very large fish each year Growing fewer larger fish could

potentially be accomplished in the same time frame as more smaller fish but a better

understanding13 of how density13 alters growth13 rate13 would13 be13 required to13 be13 confident of this

49

13

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower13 Colorado13 River Multi-shy‐Species13

Conservation Program13 (LCRMSCP) under Work Task C10 We13 thank Ty Wolters13 Tom13

Burke13 and Eric13 Volkman for their support of this research and Frank Agygos and Dave

Billingsly13 of the Bubbling13 Ponds Fish Hatchery13 for their willingness to participate in13 this

research13 and13 for their technical assistance We also thank the LCRMSCP fish group from13

Boulder City13 NV for their assistance with harvesting13 ponds and tagging13 fish13

50

13

Literature13 CitedAnders P J 1998 Conservation aquaculture and endangered species can objective science13

prevail13 over risk13 anxiety Fisheries 23(11) 28-shy‐31

Anderson R O and R M Nuemann 1996 Length weight and associated structural indicesPages 447 ndash 482 in B R Murphy13 and D13 W Willis13 editors13 Fisheries techniques13 2ndedtion American Fisheries13 Society13 Bethesda13 Maryland

Bain M B J T Finn and H E Brooks 1988 Streamflow regulation and fish communitystructure13 Ecology13 69382-shy‐392

Bays J H Zarbock R Whitman and T Murphy 2005 Conceptual design and managementof native13 fish refugia on the13 lower13 Colorado13 River In13 CL Spring13 and13 S Leoneditors Proceedings of two symposia Restoring native fish to the lower ColoradoRiver13 interactions13 of native and non-shy‐native13 fishes 13ndash1413 July13 1999 Las13 Vegas13 Nevada13 Restoring13 natural function within a modified riverine environment thelower Colorado River13 8ndash913 July13 1998 U S Fish and13 Wildlife13 Service Southwestern13 Region Albuquerque New Mexico Pages 167-shy‐177

Bertalanffy L Von 1957 Quantitative laws in metabolism13 and growth13 Q Rev Biology 32217 ndash 231

Bingham T B Scheer and C McAda 2003 Propagation facilities in Grand Valley (24 RoadHatchery Horsethief13 Ponds and13 grow-shy‐out ponds) for captive13 rearing13 ofendangered13 fishes for the13 upper13 Colorado13 River basin13 Colorado River RecoveryProgram FY2003 annual project report13 US Fish and13 Wildlife13 Service GrandJunction13 4pp

Birchell G J and K Christopherson 2004 Survival growth and recruitment of larval andjuvenile razorback13 sucker (Xyrauchen texanus) introduced13 into13 floodplain13 depressions13 of the13 Green River Utah13 Final report13 Upper13 Colorado13 RiverEndangered Fish Recovery Program13 Project No C-shy‐6RZ Publication Number 04-shy‐1513 Utah13 Division of Wildlife13 Resources Salt Lake13 City13 Utah13 67 pages

Brannon E L 1993 The perpetual oversight of hatchery programs Fishery Research 1819-shy‐27

Brett J R 1979 Environmental Factors and growth pages 599-shy‐67513 InW S Hoar13 D13 J13 Randall and J R Brett (eds) Fish Physiology Volume 8 Bioenergetics and GrowthAcademic Press New York

Brooks J E 1986 Annual reintroduction and monitoring report for razorback suckerXyrauchen texanus in the Gila River Basin Arizona 1985 US Fish and WildlifeService13 Offices of Endangered13 Species and Fishery13 Resources Albuquerque 23 pp

51

13

Brunson13 R E and K D13 Christopherson13 200513 Larval13 razorback13 sucker and bonytailsurvival and13 growth13 in the13 presence13 of nonnative13 fish in the13 Baeser13 floodplainwetland of the middle Green River Final report prepared for Upper13 Colorado RiverBasin Endangered Fish Recovery Program Project No C-shy‐6-shy‐rz-shy‐bt Publication13 No 05-shy‐26 Utah13 Division of Wildlife13 Resources13 Vernal13 32 pp

Bulkley R V and R Pimentel 1983 Temperature preference and avoidance by adultrazorback suckers Transactions of the American Fisheries Society 112601-shy‐607

Burke13 T13 199513 Rearing13 wild razorback13 sucker larvae in13 lake-shy‐side13 backwaters13 LakeMohave ArizonaNevada Proceedings of the Desert Fishes Council 2635

Busacker G P I R Adelman and E M Goolish13 199013 Growth13 Pages 363 ndash 387 in C BSchreck and p B Moyle editors Methods for fish biology American FisheriesSociety Bethesda Maryland

Castro V B Grisdale-shy‐Helland S J Helland T Kristensen S M Jorgensen J Helgrud13 GClaireaux A P Farrell A Krasnov and H Takle 2011 Aerobic training stimulatesgrowth and promotes disease resistance in Atlantic salmon (Salmo salar)Comparative Biochemistry and Physiology -shy‐ Part A Molecular amp IntegrativePhysiology13 160(2) 278-shy‐290

Czapla T E 2002 Facilities plan for the production of endangered fishes to meet statestocking13 plans13 as13 part of the13 Upper13 Colorado13 River Endangered13 Fish RecoveryProgram Upper Colorado River Basin Recovery Implementation Program US Fishand Wildlife Service13 Denver13 9 pp

Davidson W 1997 The effects13 of exercise13 training on teleost fish a review of recentliterature Comput Biochem Physiol 117A67ndash75

Figiel Jr C R 2005 Annual report fiscal year 2004 Willow Beach National13 Fish HatcheryUS Fish and Wildlife13 Service Willow Beach 17 pp

Figiel Jr C R M E Ulibarri G Carmichael J Seals and J N Hanson 2005 Intensive13 fish13 culture of warmwater native fishes at a coldwater fish hatchery Pages 164-shy‐16613 inProceedings of two symposia restoring native fish to the lower Colorado13 River13 interaction13 of native13 and13 non-shy‐native13 fishes July13 13-shy‐1413 1999 Las Vegas Nevada USFish and Wildlife Service Southwest Region Albuquerque New Mexico

Gerking13 S D 1978 Ecology of freshwater fish13 production13 Halstead Press13 New13 York

Gustafson W and Q Bradwisch 2000 Wahweap operation and maintenance -shy‐-shy‐ UtahColorado River Recovery Program FY 2000 annual project report Project No 29cUtah13 Division of Wildlife13 Resources Page AZ 3pp

52

13

Hamman R L 1985 Induced spawning of hatchery-shy‐reared13 razorback sucker ProgressivFish Culturist 47(3) 187-shy‐189

Hanson J N 1996 Annual report fiscal year 1996 Willow Beach National Fish HatcheryUS Fish and Wildlife Service13 Willow Beach 9pp

Irving D S Seversen and M Montagne 2004 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2004 annual project13 report Report No 29b US Fish and13 Wildlife13 Service Vernal 3pp

Jorgensen E H and13 M Jobling 1994 Feeding and13 growth13 of exercised13 and13 unexercised13 juvenile Atlantic salmon in freshwater and performance after transfer to seawaterAquaculture International 2 154-shy‐164

Kaeding L R and D B Osmundson 198913 Colorado13 Squawfish13 and13 razorback sucker grow-shy‐out pond studies as part of conservation measures for the green mountain andRuedi reservoir water sales Final report for agreement number 6-shy‐AA-shy‐60-shy‐00150

Koebele13 B P13 198513 Growth and the size hierarchy effect an experimental assessment ofthree proposed mechanisms activity differences disproportional food acquisition13 pysiological stress Environmental Biology of Fishes 12 181-shy‐188

Kretschmann A E and L L Leslie 2006 Razorback sucker (Xyrauchen texanus) status13 reproduction and recruitment in Senator Wash Reservoir CA Final Report13 to USBurea of Reclamation Cooperative Agreement No 00-shy‐FG-shy‐34-shy‐ 0009 p 32 ArizonaGame and Fish Department Phoenix

Marsh13 P13 C13 1987a13 Digestive tract13 contents13 of adult razorback suckers13 in Lake13 MohaveArizona-shy‐Nevada Transactions of the American Fisheries Society 116117-shy‐119

Marsh P C 1987b Native fishes at Buenos Aires National Wildlife Refuge and ArizonaState University Research Park Arizona opportunities for management researchand public13 education13 on13 endangered species13 Proceedings of the Desert13 FishesCouncil 1967-shy‐78

Marsh P C 1994 Rearing native Colorado River fishes in golf course ponds Arizona StateUniversity Tempe 22 + pages

Marsh13 P13 C13 200013 Fish population13 status and evaluation13 in13 the Cibola13 High Levee PondFinal report agreement number 99-shy‐FG-shy‐30-shy‐00051 US Bureau of ReclamationBoulder City13 Nevada13 20 pages

Marsh P C and C A Pacey 1998 Growth of wild adult razorback suckers13 in Lake13 Mohave13 Arizona-shy‐Nevada13 Final report13 US Bureau of Reclamation Boulder City Nevada 25pages + appendices

53

13

Marsh P C B R Kesner and C A Pacey 2005 Repatriation as s management strategy13 to13 conserve a critically13 imperiled fish species North American Journal of FisheriesManagement 25 547-shy‐556

Marsh P C and C A Pacey 2005 Immiscibility of native and non-shy‐native13 fishes Pages 59-shy‐63 inMJ13 Brouder13 CL13 Springer13 and CS13 Leon13 editors13 Proceedings of two13 symposia Restoring native fish to the lower Colorado River interactions of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 NV and13 Restoring natural13 function within a modified riverine environment the lower Colorado River13 July13 8-shy‐913 1998 Las Vegas NV US Fish and13 Wildlife13 Service Southwest Region AlbuquerqueNew Mexico

Marsh13 P13 C13 and J13 E Brooks13 198913 Predation13 by ictalurid catfishes as a deterrent13 toreestablishment of hatchery-shy‐reared13 razorback sucker The Southwestern Naturalist34188-shy‐195

Matthews R A 2005 Ichthyopthirus multifiliis Fouquet and Ichthyopthirosis infreshwater13 teleosts13 Pages13 159-shy‐218 in Advances in Parasitology volume 59 J RBaker R Muller D Rollinson (eds) Academic Press

McCarthy13 M S and W L Minckley 1987 Age estimation for razorback sucker (PiscesCatostomidae) from13 Lake Mohave Arizona and Nevada Journal of the Arizona-shy‐Nevada Academy of Science 2187-shy‐97

Minckley13 W L13 198313 Status of the razorback13 sucker13 Xyrauchen texanus (Abbot)13 in13 thelower Colorado River basin13 The Southwestern13 Naturalist13 28(2) 165-shy‐187

Minckley13 W L13 199113 Native fished of the Grand Canyon13 region an obituary13 Pages 124-shy‐177 in Colorado River ecology and dam13 management National Academy PressWashington13 DC

Minckley13 C13 O and M LaBarbara13 199913 Report13 on13 native fish grow-shy‐out facilities13 at Cibolaand Imperial National Wildlife Refuges 1993-shy‐199513 US Fish and13 Wildlife Service13 Parker Fishery Resources Office Parker Arizona

Modde13 T13 199613 Juvenile razorback sucker (Xyrauchen texanus) in a managed wetlandadjacent13 to the Green13 River13 Great13 Basin13 Naturalist13 56375-shy‐376

Modde T KP Burnham and E J Wick 1996 Population status of the razorback sucker13 inthe middle Green River (USA) Conservation13 biology 10 110-shy‐119

Modde13 T13 and G13 B Haines13 200513 Survival13 and growth of stocked razorback13 sucker andbonytail in multiple floodplain wetlands of the middle Green River under resetconditions13 Final report prepared for Upper Colorado13 River13 Basin RecoveryImplimentation Program US Fish and Wildlife Service Vernal 66 pp

54

13

Modde T Z H Bowen and D C Kitcheyan 2005 Spatial and temporal use of a spawning13 site in the middle Green River by wild hatchery-shy‐reared13 razorback suckers13 Transactions of the American Fisheries Society 134937-shy‐944

Mueller13 G13 199213 The native fish work13 group13 -shy‐ a multiagency endeavor to improve thestatus of the razorback sucker in Lake Mohave AZ-shy‐NV13 Proceedings of the DesertFishes Council 2369

Mueller G 1995 A program13 for maintaining the razorback sucker in Lake MohaveAmerican Fisheries Society Symposium 15127-shy‐135

Mueller13 G13 200613 Ecology of the bonytail13 and razorback13 sucker and the role of offchannelhabitats13 in their13 recovery Scientific13 investigations13 report 2006-shy‐5065 US GeologicalSurvey13 Denver

Mueller G and E Wick 1998 Testing of golf course ponds at Page Arizona for suitability13 as grow-shy‐out facility for razorback sucker using surplus fish from13 Ouray NationalFish Hatchery National Park Service US Fish and13 Wildlife13 Service and UtahDivision of Wildlife13 Resources 28 pages

Mueller13 G13 and T13 Burke13 200513 Survival13 of young13 razorback13 sucker (Xyrauchen texanus) inrelation to13 stocking rates13 (fishha)13 and13 in the presence13 or absence13 of predatorcommunities in Lake Mohave Arizona-shy‐Nevada13 Pages13 155-shy‐16313 in Proceedings of two13 symposia restoring native fish to the lower Colorado River interaction13 of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 Nevada US Fish and Wildlife13 Service Southwest Region Albuquerque New Mexico

Mueller13 G13 J13 Carpenter13 and P13 C13 Marsh13 200413 Cibola13 High Levee Pond annual report 2004US Geological Survey Fort Collins13 Science Center13 Colorado13 and Arizona StateUniversity Tempe 23 pages

Nesler T P K Christopherson J M Hudson C W McAda F Pfeifer and T E Czapla 2003An integrated stocking plan for razorback sucker bonytail and Colorado13 pikeminnow for the Upper Colorado River Endangered Fish Recovery ProgramAddendum13 to State Stocking Plans Upper Colorado River Basin Recovery13 Implementation Program 12 pp

Papoulias13 D and W13 L Minckley13 1992 Effects13 of foo availability13 on survival and growth13 of larval razorback suckers13 in ponds Transactions of the American Fisheries Society121340-shy‐355

Paukert13 C P D L Ward13 P J Sponholtz13 and K13 D Hilwig13 Effects13 of repeated hoopnetting13 on bonytail chub13 Journal of Freshwater13 Ecology13 20(4) 649-shy‐653

Pfeifer F M13 C Baker13 and M13 Montagne13 199913 Propagation13 facilities13 in the13 Grand Valley13 (24 Road13 Hatchery13 Horsethief13 Ponds and13 grow-shy‐out ponds) for captive rearing of

55

13

endangered13 fishes for the13 Upper Colorado13 River Basin13 Colorado13 River Recovery13 Program FY 99 annual project report Project No 29a13 US Fish and Wildlife Service13 Grand13 Junction13 5pp

Pfeifer F S Seversen and M Montagne 2003 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2003 annual reportProject No 29b13 US Fish and Wildlife13 Service Vernal13 4pp

Rabago-shy‐Castro J L Sanchez13 J G Perez-shy‐Castaneda R and13 Gonzalez-shy‐Gonzlez A 2006Effects of the prophylactic use of Romet-shy‐3013 and13 copper13 sulfate13 on growth13 condition13 and feeding13 indicies in13 channel13 catfish (Ictalurus punctatus) Aquaculture 253 343-shy‐349

Reinitz GL L E Orme and F N Hitzel 1979 Variations of body compositio and growth13 among strains of rainbow trout Transactions of the American Fisheries Society 108204-shy‐207

Ruppert13 J13 B P B Holden13 and P D Abate 1999 Age estimation and growth of razorbacksucker13 Xyrauchen texanus in Lake13 Mead Nevada Proceedings13 of the Desert FishesCouncil 3040

Schnoor K D and J Logan 2002 Operation and maintenance of JW Mumma nativeaquatic13 species restoration facility Colorado Colorado River Recovery Program FY2002 annual project report13 Project No 29d Colorado13 Division of Wildlife Alamosa3pp

Salisbury13 L13 1998 Factors13 affecting razorback13 sucker growth13 in Lake13 Mohave backwaters13 MS Thesis13 Unviersity13 of Nevada13 Las13 Vegas

Schooley J13 D13 and P C13 Marsh13 2007 Stocking of endangerdd13 razorback13 suckers13 in thelower Colorado River Basin13 over three decades 1974-shy‐2004 North American Journalof Fisheries Management 27 43-shy‐51

Severson S H H M Tyus and G B Haines 1992 An evaluation of feeds for raisingrazorback sucker Xyrauchen texanus Journal of Applied Aquaculture 155-shy‐65

Toney D P 1974 Observations13 on the13 propagation13 and13 rearing13 of two13 endangered species13 in a hatchery environment Proceedings of the Annual Conference of the Western13 Association of State Game and Fish Commissions 54 252-shy‐259

Tyus H M13 1998 Razorback sucker13 (Xyrauchen texanus) recovery plan13 University13 ofColorado Center for Limnology Boulder13 76 pages

Tyus H M13 and13 S H Severson 1990 Growth13 and13 survival of larval razorback suckers fedfive formulated diets The Progressive Fish Culturist 52197-shy‐200

56

13

Ulibarri M E 2003 Annual report fiscal year 2001 Dexter National Fish Hatchery13 andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 26 pages

Ulibarri M E 2003 Annual report fiscal year 2002 Dexter National Fish Hatchery andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 59 pages

USBR 2006 Lower13 Colorado13 River Multi-shy‐Species Conservation Program final fishaugmentation plan Boulder City 19 pp

USFWS 2002 Razorback sucker (Xyraouchen texanus) recovery goals Amendment andsupplement to the Razorback Sucker Recovery Plan13 US Fish and Wildlife Service13 Region 6 Denver13 Colorado

USFWS 1999 Annual report 1999 Ouray National Fish Hatchery Vernal 25pp

USFWS 2004 Management plan for the big-shy‐river13 fishes of the13 lower13 Colorado13 river basinamendment and supplement to the bonytail humpback chub Coloradopikeminnow and razorback sucker recovery plans

USFWS13 2005 Station13 profile13 of the13 Dexter13 National Fish Hatchery13 and Technology CenterUS Fish and Wildlife13 Service Dexter

Valdez R A P G Mangan R Smith and B Nilson 1982 Upper Colorado River fisheriesinvestigations13 inW H Miller J J Valentine D L Archer H M Tyus R A Valdezand L13 Kaeding13 editors13 Colorado River Fishery13 Project13 Part 2 Field13 investigations13 US Bureau of Reclamation Salt Lake City Utah

WBNFH 2004 Culture methods of the endangered razorback sucker Xyrauchen texanusUS Fish and Wildlife13 Service Willow Beach National Fish Hatchery13 8 pp

Ward D 2008 Effects of disease treatments on growth of razorback sucker ReportSubmitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 Inpartial fulfillment of work task C10 agreement number 06FG30039

Ward13 D13 M Childs and W Persons 2007 Factors13 affecting13 growth13 of razorback sucker13 (Xyrauchen texanus) in captivity Literature review and knowledge assessmentReport Submitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 In partial fulfillment of work task C10 agreement number 06FG30039

57

Appendices

Appendix 1 Survey Questions Survey of Razorback Sucker Culture in the

Southwestern United States

The enclosed survey is being distributed by the Arizona Game and Fish Department to razorback sucker culture facilities throughout

the Southwestern United States The purpose of this survey is to consolidate information regarding culture of this species so that

appropriate facility improvements can be considered for Bubbling Ponds Hatchery in Arizona Specifically we wish to increase

growth rate and production efficiency at the hatchery Information gathered in this survey will be summarized in a final report to US

Bureau of Reclamation in Boulder City NV and disseminated to all facilities that participate in the survey A workshop to discuss

the findings of this study as well as to share general information concerning razorback sucker culture will be organized by the

Arizona Game and Fish Department at the conclusion of this study and all participants will be invited

Thank you for taking the time to fill out this survey Please contact Mike Childs if you have questions or would like to discuss the

survey

Mike Childs

mchildssedonanet

(928) 639-1346

(928) 634-1279

Facility_____________________________________ Date___________________

Contact Phone _____________________________

ContactPerson_______________________________

Contact Email _______________________________

1 Water quality ranges at this culture facility

Season

Spring (Mar-May) Summer (Jun-Aug) Fall (Sept-Nov) Winter (Dec-Feb)

Temperature (C)

PH

DO (mgL)

PO4 (mgL)

TDS (mgL)

Hardness (mgL)

CaCO3

Pathogens

37

13

lt=amp

feeds (Table 7) as well as differences in grading or sorting practices Some of these

differences are13 related13 to13 whether13 or not razorback suckers13 are13 being13 reared13 in extensive-shy‐

culture13 facilities13 (ponds) or intensive-shy‐culture13 settings13 (raceways13 o tanks)13 Some13 practices13

are unique to a single facility13 or a couple of facilities (Table 6)13 Managers at each facility13

were asked to identify the biggest13 difficulty or constraint13 that13 they experience when13

growing-shy‐out juvenile13 razorback suckers13 at their13 respective13 location13 Space constraints13

water quality and disease problems were the main factors limiting production of razorback

suckers13 at these13 facilities13 (Table13 8) Calculated or reported growth rates from13 the literature

vary widely (Table 9) and range from13 02 to 18 mmday These growth rates indicate that

juvenile razorback suckers have a very high growth potential under optimal rearing

conditions13

Table13 4 Stocking13 densities13 for larvae13 and13 fry in ponds

$amp( )(+amp-( 01-2(3(4amp56( 4amp56(+amp-( 01-2782-( $amp () + --amp +amp0amp)+amp 12-3amp ( )+amp0amp+amp --amp +amp0amp)+amp 42556789amp8 ( +amp0ampgt+amp 3amp +amp0amp+amp A-BC-Damp (E + 3amp )+ F-6ltamp ) G+ 3amp G+

Table13 5 Rearing13 densities13 at intensive13 culture13 facilities13

$amp( )amp+(($-( $0( 12(3$+( 40((amp05( 67((amp05( 8$9(407$( $amp amp())amp++-$amp 0 1 0amp2amp1amp 3amp2amp4 0544

6amp())amp++-$amp 610 021 4amp2amp47amp 3amp2amp77amp 058 9$amplt+)amp 4amp())amp++-$amp 00 1 7amp2amp77amp 851amp2amp0amp 05

6amp())amp++-$amp 610 77amp2amp1amp 0amp2amp1amp 053

19

13

Table13 6 Rearing13 practices13 that are13 unique to13 specific rearing13 facilities13 $$amp( )$+-(amp$-(0(1-amp2034( $amp()amp+( -0$(12(33+(amp(amp134$53+(amp$amp3+(6amp+(

723(843(1$8(422(6amp+(42amp(4(423(19$43( 343( lt34$53(6amp+(6(4($03(amp4+94amp(842($1$1(63$$34(amp+(63626243( =amp+(gtamp94ampA( B3(1(1$+53+C3+(amp+(1$43(1(3D0$(1(amp443(amp+(amp443( 734231(amp( B3(1(193(44(1(34amp(amp(+49E(6amp+( -E3(F3+( G3amp(1(12(amp(H3(13$(4ampE(C(IJK($$amp( A( L43(+A3(4(6303amp4(63+4ampM(66$3D3amp4$(34amp(amp(6amp+(C((4amp3( L$$8(392(

B0$+3(

N43D(13+(4($0$(12M(amp+(639$53+($0$(12(+34( G3amp(12(amp(399$4amp(4+(938A(842($(2343+(843( N443D643+(3amp(12(amp(amp34(63amp(amp(423(O$+(G03( )amp+(3(134$53+(6(4(39364(1(1A(4(44(423D(amp((D3(amp4$(+34(

Table13 7 Types of feed used at razorback sucker13 hatcheries13 $amp ()amp+-amp0- $$)1amp23 45-amp)-$5)1amp23 $amp()amp+( -amp$amp+(amp+( -amp012$3+(amp+4(amp5215$(0+( 65ampamp7(85209(+2($1(87((15315lt=(+2(

+amp+amp(amp(55$5$2gt( 21( Aamp+(amp+( )amp+(012$3+(B29(5$05$95($$2(5amp+(

199524(amp5215$(0+( 65ampamp7(85209(+2($1(87(15315lt=(+2(amplt( 29gt(51($51(amp9(2(25=(C(DD(0+(

E15amp+(Famplt2amp( G1$5(lt1lt$51(25amp=( HIJKH(Dlt1amp(15315lt=(+2(I(C2(CH(+5gt( )11$gt($511(02+(15315lt=(+2(

$1(87(15315lt=(+2(D5$$(3(lt5$$gt(02+(gt( 6lt=(511B(

L15gt( G1$5(lt1lt$51(25amp=(Aamp+( amp+(

HIJKH(Dlt1amp(15315lt=(+2(I(C2(CH(+5gt( )11$gt($511(02+(15315lt=(+2(

$1(87(15315lt=(+2($1(87($B(amp=amp( 5$Damp(+2(

M$$B(5lt9(-5$+( NO515(G1$5(219( L2+1(15ltB5gt(Aamp+(5amp+( amp$amp+(amp+(

1amp(91D(amp5$(Pamplt5$amp4( 8gtlt$34(1$amp54(5amp+(5120lt5$( $5amp=2amp()amp+(012$3+(B29(5$05$95( $$2(5amp+(19952Q(amp12152( 1+lt2amp(

$1(87(15315lt=(+2($1(87(15315lt=(+2( $1(87(15315lt=(+2(

Table 8 Factors limiting production at major razorback sucker facilities

$amp( )amp+(-0+1((2$(0amp1ampamp(-34amp( $amp()amp+( -(01$2(34+(546(amp(0amp(01amp(541(13( -741( 803(3amp41amp4(9((+ltlt1amp4(03(amp(44amp(2=(4(

+ltlt3$4(4(2amp4amp(014(1gt13=(43=( 1amp+(amp34amp( 803(3amp41amp4(1$4+(4(541(A$4B(amp+(+$C+(

7Bamp($244amp(lt(1313$4amp(B42( D1B( E41(A$4B(01$2(3+(B(66(1amp(amp+(2ampamp(

Eamp41(420141(464(1A1($$(lt6(4((2C+(amp+1( 803(3amp41amp4(1$4+(4(541(A$4B(amp+(+$C+(7Bamp(

E$$5(36( 803(3amp41amp4F(15amp(lt6(4(amp31amp$B($11(gt( 1$4(amp(ampltlt3amp4(03(amp(44amp(lt1(amp5(lt6(

GC$+( 8221(420(3amp(4(6691A1amp(051((4(410$(+(4( 661(1amp+541(020amp(4(=0(0amp+(3$F(

20

13

$amp(

)+-amp)amp)

0$amp1

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1ampamp1

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442

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$

amp()

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lt(

lt=(gt

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[(]amp-(X81

(M1

235(6

V7X^7(444

+

A(

-ampA(amp(Samp

D8[(]amp-(X81

(M1 (

(23Qlt(6(

V7X^7(444(

+ A(

-ampA(amp(

C8(

(amp8(

[(]amp-(X81

(M1 (

235J

(P(23I(6(

_8(44lt(

S

-(

([(amp(Samp

D8(=I

(gtgt(

(5I

(gtgt((

ampD(B(

8(8

8amp

(OA(

`(A-B(8(

235K

(P(23Jlt

(6(3(

0

-- (

ampD(^

(4

4lt(

5(gtgt(

(QJ2

(gtgt(amp(=(a(5

(gtamp

1(S D(--D

(C1

(gt

gt-(amp(

ZampD

amp1(Samp

D(V1(

23=J

lt(6(

OBB

((

-(=22

Q(

L+amp-(B81(b

K5(gt

gtc((8D((KKK

(S ((

V+-D(

235J

(R(6(

V7GZ(=2

2J(

7D(d=22

(gtgt(amp(F=((Samp

D(ampD(1+8D(eQ22

(gtgt(8U(gtamp

18(-(

fampamp

(Oamp

D(V1(

23Qlt

=(6(

OBB

((

-(=22

Q(

N+-(B81(8D

((=

522(S

((

ggt(H

+(

32J

(6(

0

-- (

445(

]--(8S

Camp

D(-+-(B81(

ggt(H

+(

3lt(6(3(

0

-- (

ampD(G(=22

5(

7D(8(=5(gtgt(-+(1D

(Q22

(gtgt(9(amp

D(B(8

gtgt (

Table9Reportedandcalculatedgrowthratesfromtheliterature

Calculatedgrow

thratesbasedon

informationprovidedinliterature

aApproximationsofmaximum

grow

thpotential(basedon

average13 maximum

sizesiffishreportedatharvest

21

13

General Information on Factors that Affect Fish Growth

Growth in fish is extremely variable and is impacted by many different

physiological and environmental factors Growth rates are known to change with size and

age sex season activity level density amount13 of living space quality and quantity of food

genetics and temperature (Brett 1979) Growth experiments conducted at different times

of year can result in growth rates that are not comparable As fish become larger their

physiological13 potential to grow decreases making determination of growth rate dependent

on the size of the starting fish and the length of the experiment (Busacker et al 1990)

Genetic factors also have great potential to influence growth rate Some species have

strains13 and13 races13 that display vastly different growth potentials (Reinitz et al 1979) All of

these factors combine to make assessment of the individual factors controlling fish growth

difficult13

Water temperature is probably the most important variable affecting growth rate13

All of the basic functions that affect growth such as feeding digestion and metabolism are

temperature-shy‐dependent13 Growth13 is inseparably13 tied13 to13 bioenergetics13 and13 therefore13 also13

tightly tied to temperature When temperatures are below optimum daily temperature

fluctuations can stimulate growth Photoperiod is also commonly linked to water

temperature and can influence growth rates in fish (reviewed in Brett 1979)

Fish density13 is known to13 affect growth13 and13 can alter13 growth13 rates13 in several ways13

Fish that exhibit strong territorial behaviors13 or natural schooling tendencies13 will

experience reduced growth if densities are too high or too low (Brett 1979) Dominance

hierarchies where some fish feed more aggressively than others can also lead to high

variability13 in growth13 rates13 (Koebele13 1985) Crowded13 conditions13 also13 cause physical

interference13 between13 fish and13 poor water13 quality13 which13 reduces13 growth13 (Busacker13 et al13

1990) The effects of fish numbers space and feeding opportunity are frequently correlated13

and often13 difficult13 to distinguish (Brett13 1979)13

It is impossible to study the effects of environmental factors on growth without also

evaluating feed rations (Brett 1979) Amount of food quality of the diet particle size

number of feedings per day and time of feeding have all been shown to affect growth

(Busacker et al 1990) In controlled laboratory studies food is usually fed ad libitum13

22

13

(constantly available) and other variables are altered to assess impacts of environmental

factors13 on growth13 These studies13 are13 usually13 conducted13 in tanks13 or raceways13 because13

researchers must verify that food is constantly available to the fish which is difficult to do

in large pond environments where the fish and the bottom13 are often not visible (Busacker13

et al13 1990)

Specific Information13 o Razorback13 Sucker13 Growth

Variable13 growth

Growth in razorback suckers is naturally highly variable and may be a function of

their evolutionary history (USFWS13 2002)13 Minckley (1983) speculated that13 wide size

variation in a single cohort of razorback suckers may be adaptive with fast-shy‐growing13 fish

that13 reproduce at a young13 age surviving13 better in13 high discharge years and slow-shy‐growing13

smaller fish surviving better during drought periods This highly variable growth rate

makes rearing razorback suckers in a production setting difficult because fish from13 a single

cohort do not reach the target stocking size simultaneously One of the major tasks for

aquaculture is to maximize both individual growth and total production13 (Gerking13 1978)13

This becomes more difficult when the species being cultured exhibits highly variable

growth13 rates13 because of genetic influences as is the case with razorback13 suckers13

Razorback13 sucker growth13 is typically very13 rapid13 during13 the first13 year of life13 and then13

declines with age First year growth can be as low as 50 mm and as high as 350 mm (Valdez

et al13 1982 Minckley13 1983 Mueller13 1995) Razorback sucker13 grow rapidly13 for

approximately the first five or six years of life and then growth slows13 (McCarthy13 and13

Minckely 198713 Tyus 199813 Minckley et13 al 1991)13 Growth of older individuals in13 extant13 wild

populations is very13 low (Minckley 198313 Tyus 198813 Modde13 et al 1996)13 Wild growth13 rates

for mature adult fish in Lake Mohave based on PIT tag recaptures were often too small to

be accurately measured for both males and females over the time period of 1987-shy‐199713

(Marsh and Pacey 1998) This information suggest it will take substantially longer to rear

fish to13 increasingly13 larger13 stocking13 sizes (40013 ndash 500 mm TL) than it did to reach the target

size of 300 mm TL

Growth in ponds

23

13

One of the main strategies for maintaining genetic refugia and self-shy‐sustaining13

populations of razorback13 sucker in the lower Colorado13 River basin13 is to rear razorback13

sucker13 larvae13 in production13 ponds until they13 are13 a suitable13 size for stocking13 (USFWS13 2004)

Pond culture has proven useful to promote rapid growth of juvenile razorback suckers

(Kaeding and Osmundson 1989) Marsh (1994) reported that growth rates of razorback

suckers13 reared13 in golf-shy‐course13 ponds exceeded13 the13 best growth13 rates13 obtained13 under

intensive13 culture13 conditions13 at federal hatcheries13 especially13 during the13 first several years13

of life Growth rates in these semi-shy‐natural ponds are also comparable to estimated growth

rates13 of juvenile13 wild13 fish (McCarthy13 and13 Minckley13 1987) Modde13 and13 Haines13 (2005)

reported13 the13 greatest growth13 rates13 in the13 largest and13 deepest floodplains13 with13 the13 greatest

amount of submergent vegetation but excellent growth and survival of fish in a grow-shy‐out

pond is of little value if there is not an efficient way to collect the fish from13 the pond

(Kaeding and Osmundson 1989)

Temperature13

Bulkley and Pimentel (1983) used shuttle boxes in the laboratory to determine a

temperature preference13 for razorback suckers13 of 23-shy‐24degC13 In13 their13 studies13 razorback

suckers were found to avoid temperatures below 118 degC or above 286 degC Razorback

suckers at Bubbling Ponds Hatchery are more active in the spring and feed better as

photoperiod increases even prior to water temperatures rising (Frank Agygos personal

communication) Table 3 briefly summarizes water temperature data from13 each facility

Detailed seasonal water temperature profiles are not currently available for many

razorback grow-shy‐out sites13

Density13

Extensive studies have been conducted on commercially important species to

evaluate stocking densities and feeding rates that maximize production For these species

controlled experiments under laboratory conditions have established relationships

between temperature density and feed ration on growth (Brett 1979) but this information

is sporadic13 or non-shy‐existent for razorback suckers13 (Bays13 et al13 2005) Fish culturists13 with13

24

13

experience13 rearing13 razorback suckers13 typically13 have13 target stocking13 densities13 that13 they use

(Tables13 4 -shy‐ 5) These stocking densities have largely been determined over time by trial

and error These approximate stocking densities provide a good starting point for more

controlled13 types13 of replicated13 pond studies13

Feed ration

Razorback13 suckers are currently13 being13 fed a wide variety13 of prepared diets (Table 7)

that range from13 a slow-shy‐sinking salmon feed manufactured by Silver Cupreg to a spirulina

and krill-shy‐enhanced catfish feed made by Rangenreg Most locations are feeding 20 ndash 50

body13 weight per13 day13 Methods13 for culture13 of razorback sucker13 larvae13 in intensive13 settings13 at

fish hatcheries are well documented (Figiel 2005) and various larval fish diets have been

evaluated13 (Tyus and13 Severson 1990 Severson et al13 1992) but no standardized13 procedures

are used for feeding13 larval13 fish in13 intensive settings13

Razorback sucker larvae are also effectively reared in pond environments using

natural foods supplemented with larval fish diets and survival is high when no predators

are present13 (Mueller 2006)13 Growth rates for larval13 and early juvenile razorback13 suckers

may increase with pond fertilization Diet and physiological studies on wild razorback

suckers indicate that they feed on plankton as well as benthic organisms during their entire

life (Marsh 1987) Artificially fertilizing ponds may greatly increase production capacity

and growth rates for razorback13 sucker (Papoulias and Minckley13 1992) and warrants

further13 investigation13

Handling stress

Handling stress13 has13 been shown to13 influence growth13 rates13 Paukert13 et al (2005)

found that growth of bonytail chub was reduced by 26when compared with controls

after being13 repeatedly13 captured and handled in13 hoop13 nets13 Handling13 effects are likely13 to be

similar for razorback suckers that are repeatedly13 captured and sorted in13 a hatchery13 setting13

Razorback suckers that are handled at Willow Beach National Fish Hatchery will commonly

not eat for two weeks after handling (John Scott personal communication) This creates a

difficult situation13 for production13 facilities because13 fish13 need to be sorted to ensure13 large13

25

13

aggressive fish do not interfere with growth of smaller individuals but frequent handling

and sorting13 causes stress related reductions in13 growth13

Measuring Growth in Captive Fish

Weight is the traditional measure used to estimate growth or production in

aquaculture settings13 Groups of fish are typically13 weighed and an average individual13 weight13

is computed (Busacker et al 1990) Although this method is often logistically the easiest it

may not be the most informative for species with highly variable growth rates like

razorback suckers especially when target lengths must be reached before fish can be

stocked Weight can also be highly influenced by things like stomach fullness or

development of gonads (Busacker et al 1990) Condition factor or relative weight can also

be used to assess growth of fish but these tools may be more robust predictors of fecundity

than of growth (Anderson and Neuman 1996) For some species sexes need to be

distinguished because males and females may differ in morphology (Anderson and

Neumann 1996) Mueller (2006) analyzed growth rates based on PIT tag recaptures of 86

razorback suckers13 in High13 Levee Pond13 and13 found13 that differences13 in growth13 do not appear13

to occur until fish are over 450 mm TL at which time growth rate in males slows while

females continue to grow at a slightly higher rate This would indicate that sex may not be

an important factor to consider when examining growth rates unless the target grow-shy‐out

size is above 450 mm TL

The best measures of growth are often determined from13 the length and weight of

individuals rather than from13 groups of fish (Anderson and Nuemannn 1996) because

individual growth rates give better estimates of confidence and variance (Busacker et13 al

1990) Length frequency analysis or recapture of previously marked individuals of a known

size is likely to yield the most useful information for razorback sucker growth The success

of any of these methods depends on proper sampling procedures that are representative of

the population as a whole (Busacker et al 1990) Sampling methods that are known to be

size-shy‐biased such as trammel nets (Mueller et al 2004) or cast nets should not be used when

trying to measure growth rates13

26

13

Conclusions

For razorback sucker survival is largely associated with stocking size Additional

focused13 research13 is therefore13 needed to13 identify13 ways13 to13 increase13 growth13 rates13 of captive-shy‐

reared13 razorback sucker Growth13 rate13 in fish is controlled13 by many factors including fish

size and age temperature density and feed ration which can all be highly correlated

Growth of razorback suckers is also inherently variable which makes the task of identifying

the key factors that13 affect13 growth in13 captivity even more difficult The focus at most

razorback rearing facilities13 is production so the13 types13 of data that are13 collected13 are13 often

insufficient for detailed13 evaluations13 of individual rearing13 practices13 on growth13 Surveys of

existing13 razorback sucker13 rearing facilities indicate that culture methods vary widely and

the types of growth data13 that13 are collected are not13 standardized13 Replicated studies with

detailed information on rearing location water temperature initial stocking size stocking

density and the sizes of all fish at harvest are needed in order to compare the effects of

individual rearing practices on growth This type of research will ultimately provide both

time and cost-shy‐savings to production facilities by reducing the amount of time necessary13 for

razorback sucker to reach stocking size improving overall production efficiency

Optimum13 rearing densities for razorback sucker larvae and juveniles remain to be

determined Current stocking densities will be very useful as starting point for more

detailed studies and although optimum13 rearing densities are likely to be site-shy‐specific13

replicated studies on density will provide a valuable reference for hatchery managers

Frequency13 of sorting is another13 area that needs13 further13 research Frequent

handling13 and13 sorting13 can13 cause13 stress-shy‐related13 reductions13 in growth but not sorting can

create dominance hierarchies that further reduce growth rates of subordinate individuals

The effects13 of sorting13 on overall fish growth13 in both13 pond and13 intensive13 culture13

environments warrant further investigation Research techniques for these types of

experiments are well understood and typically utilize a matrix of replicate ponds per

variable (Bays et al 2005) In every case accurate and complete records of sampling

procedures and data collection are needed in order to interpret data and make inferences

about13 growth rates (Busacker et13 al 1990)13

27

13

Additional research is also needed to evaluate long-shy‐term13 survival of stocked fish

reared in ponds compared to fish13 reared13 in intensive13 culture13 facilities13 Exercise13

conditioning13 and predator-shy‐recognition training may also increase survival of stocked fish

and be more economically feasible than rearing fish to increasingly larger sizes prior to

stocking13 The success13 of traditional fish hatchery programs is measured largely by the

number of fish stocked but hatchery programs for endangered species must measure

success in terms of long-shy‐term13 survival and species recovery (Brannon 1993 Anders 1998)

A specific list of research recommendations follows

Specific Research13 Recommendations13

bull Use replicated studies13 to establish optimum stocking13 densities13 for ponds13 and

tanks13 that can be used as13 a starting13 point for site specific refinement

bull Determine if sortinggrading13 improves13 overall growth rates13 in both ponds13 and

intensive culture facilities13

bull Investigate the use of artificial fertilizers13 to improve growth of both juvenile

and adult razorback suckers13 in ponds13

bull Determine if the razorback sucker diet gives13 better growth rates13 than cheaper

catfish or salmon feeds

bull Evaluate growth rates13 and production potential of new intensive culture

methods13 such as13 large circular tanks13

bull Evaluate13 long-shy‐term survival of fish produced from raceways13 and circular tanks13

compared to fish reared in ponds13

bull Evaluate more effective means13 of treating13 fish diseases13

bull Evaluate factors13 other than size that may increase post-shy‐stocking13 survival such

as13 exercise conditioning13 predator recognition training or rearing13 under more

natural settings13

28

13

II The Effect of Disease Treatments on Razorback Sucker

Growth

Section13 SummaryFormalin copper sulfate potassium permanganate and13 salt are all chemicals commonly13 used13 to13 treat13 Ichthyophthirius multifiliis outbreaks in captive razorback sucker (Xyrauchen13 texanus) Weexposed 190 juvenile13 razorback suckers (127 ndash 26 mm TL) to13 5 5-shy‐day treatments with13 each13 chemical to evaluate the effects13 these chemicals13 may have on growth Fish grew an average of23513 mm TL13 during the month13 study period Fish treated with formalin grew on average13 29mm TL (03 mmday) while fish treated with copper had the lowest growth averaging 20 mmTL (021 mmday) No significant differences in13 growth were observed among fish treatedwith any of the chemicals compared to untreated fish (pgt005) Reductions in growth13 as aresult of repeated chemical treatments are not likely the cause of differences in growth ratesamong13 facilities that raise razorback suckers Repeated chemical treatments may13 have otherimpacts to overall13 fitness or long-shy‐term survival but13 these effects were not13 evident13 in our study

29

13

Introduction

Preservation13 of razorback sucker13 (Xyrauchen texanus) currently13 depends on captive13

rearing and stocking programs until permanent solutions to factors that prevent wild13

recruitment are found Low survival of stocked razorback suckers (Brooks 1986 Marsh

and Brooks 198913 Marsh and Pacey13 2005) has caused target13 sizes for stocked fish to

steadily increase in efforts to reduce predation mortality (Marsh et al 2005 Schooley and

Marsh 2007) Rearing fish to larger sizes at hatcheries comes with increased costs and

creates the need to evaluate husbandry and rearing practices that may affect fish growth

Formalin copper sulfate potassium13 permanganate and salt are all chemicals

commonly used at razorback sucker rearing facilities to treat outbreaks of the protozoan

parasite13 Ichthyophthirius multifiliis ldquoIchrdquo is one of the most pathenogenic diseases of

cultured13 freshwater13 fishes (Matthews13 2005) and causes large13 losses in captive13 populations13

of endangered razorback sucker Each of these chemicals used to treat Ich only kill the free-shy‐

swimming life stage of the parasite13 requiring13 repeated doses over several13 days depending13

on water temperature These chemicals treatments are needed to prevent loss as a result

of disease outbreaks but the cumulative effects repeated disease treatments have on

growth13 are13 unknown

Copper13 sulfate13 has13 been shown to13 significantly13 reduce13 growth13 of channel catfish13 in

production13 ponds (Rabago-shy‐Castro13 2006) but it is unknown whether13 razorback suckers13

experience similar reduced growth following copper treatment Quantifying the impacts of

disease treatments on growth will help to interpret the wide differences in growth rates

observed13 at various13 razorback sucker13 production13 facilities13 throughout the13 southwest

(Ward et al 2007) If one chemical is found to have less detrimental impacts on growth

than another then it may be preferred for use as a disease treatment We evaluated growth

rates13 of razorback suckers13 under13 replicated13 and13 controlled13 conditions13 to13 assess13 effects13 of

repeated formalin copper sulfate and potassium permanganate and salt treatments on

growth13

Methods

We captured 190 juvenile razorback suckers from13 ponds at Bubbling Ponds Fish

Hatchery AZ using hoop nets or cast nets All fish were of the same age class and

30

13

averaged 179 mm total length (TL) (range13 = 127 ndash 262 mm TL)13 These fish were13 offspring13

of captive13 razorback sucker13 broodstock held13 at Dexter13 National13 Fish Hatchery13 NM13 (2007

year class) All fish were tagged with passive integrated transponder (PIT) tags and

quarantined for one month prior to the experiment to allow fish to recover from13 tagging

and become accustomed to being held in circular tanks

At the beginning of the study all fish were weighed measured and scanned for

individual tag numbers with 19 randomly selected fish placed into each13 of 10 8-shy‐foot

diameter circular tanks (Figure 2)13 Each13 tank contained13 two13 airstones13 and13 an13 individual

biofilter with a recirculating water pump (31 litersminute) that had been operating for

at least 1 month prior to the experiment to allow bacterial colonies to become

established Two tanks were designated as a control and did not receive any chemical

treatments while the other eight tanks received formalin copper sulfate potassium13

permanganate or salt treatments at two week intervals (two tanks per chemical

treatment) Formalin copper sulfate and potassium13 permanganate were treated at 1 part

per million (ppm) and salt was applied at 30 parts per thousand (ppt) These treatment

rates are commonly used to treat13 razorback13 suckers for ich at Bubbling13 Ponds Fish13

hatchery (Frank Agygos personal communication)

Figure 213 Photo ofexperimental tankswith individualbiofilters and aeration

31

13

Each treatment consisted of a series of doses applied on Wednesday Thursday and

Friday with a 90water change between each dose Biofilters were removed from13 all

tanks and held in a separate holding facility during treatments and then replaced on the

Monday following treatments after a 90water change This schedule allowed fish to be

exposed to chemical treatments for 5 consecutive days without water quality deteriorating

This 5-shy‐day chemical treatment was repeated every two weeks from13 July to October (97

days)13 for a total of 5 5-shy‐day treatments Water temperature in the treatment tanks ranged

from13 13degC (55degF) to 32degC (91degF)

Fish were fed a fixed ration of commercial razorback diet (Silvercup 4mm13 pellet)

once daily13 (2 percent body13 weight per day13 as calculated13 by13 average initial fish weight)13

At the end of the experiment all fish were again weighed measured and scanned for

individual tag numbers Growth of fish in each treatment group was compared using

analysis of variance (ANOVA) Any mortalities13 that occurred during the13 study13 were13

replaced with previously quarantined fish of equivalent size to maintain equal densities in

each13 tank13 but growth13 data was13 only13 recorded for fish which13 survived13 the13 entire13

experiment

Results

Fish at the13 start of the experiment averaged 179 mm TL (Range13 = 127 ndash 262 mm)

with no significant differences in fish length among treatment groups (F(4189) = 00183 p

gt 0999 ANOVA) On average fish grew 235 mm TL (024 mmday) during the 3 month

study13 Fish in tanks13 treated with formalin had the highest growth averaging 29 mm TL (03

mmday) while fish in tanks treated with copper had the lowest growth averaging 20 mm

TL (021 mmday) Fish in the control tanks averaged 213 mm TL in growth (022

mmday) (Figure13 3)13 Formalin-shy‐treated fish grew13 significantly faster than13 any other

treatment group but no13 significant differences in growth13 in length13 or weight were13

observed among fish treated with any of the chemicals compared to untreated (control)

fish (pgt005 ANOVA)

32

13

Figure 313 Average growthof razorback suckersexposed to a series of 5 5-shy‐day chemical treatmentsover a 97-shy‐day13 periodError bars representstandard error

Discussion13

Growth13 rates13 observed13 in our study13 (021 ndash 03 mmday) are low compared to those

reported13 in other13 studies13 of razorback sucker13 growth13 (0213 ndash 18 mmday) (Ward et al

2007) Using recirculating water systems for our study required filters to be removed and

replaced during treatments Stress to fish caused by removing and replacing filters within

the tanks as well as repeated water changes may have led to overall higher stress and

reduced growth rates compared to those reported for unconfined fish Growth in fish is

highly variable and is affected by many different physiological and environmental factors

including fish size density temperature amount of space and food (Brett 1979) We

strived to control each of these factors but other factors may have also influenced growth

in our experimental tanks During mid-shy‐summer water temperatures in the treatment

tanks reached 32degC (91degF) At these warm13 temperatures fish are very susceptible to

bacterial13 infections13 The slightly higher growth exhibited by fish in the formalin and

potassium13 permanganate treatments may have been the result of these two chemicals

33

13

being effective at controlling bacterial infections The differences in growth we measured

among treatment groups were not statistically significant and do not appear13 biologically13

meaningful during the relatively short duration of this study (97 days) although the

cumulative effects of slightly reduced growth could be biologically meaningful over longer

time frames

Reductions in growth13 as a result13 o repeated chemical treatments are not likely the

cause of differences in growth rates among facilities that raise razorback suckers

Repeated chemical treatments may have other impacts to overall fitness or long-shy‐term13

survival but these13 effects13 were13 not evident in our study It is more likely that the parasite

outbreaks themselves are the cause of different growth rates among razorback rearing

facilities rather than the chemical treatments used to treat the parasites We recommend

that hatchery managers continue to use the chemicals that are most effective at controlling

ldquoIchrdquo13 at their individual13 facilities

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower Colorado Rive Multi-shy‐species13

Conservation Plan under Work Task C10 We thank Ty Wolters and Tom13 Burke for their

support of this research and Frank Agygos and Dave Billingsly of the Bubbling Ponds Fish

Hatchery13 for their13 technical assistance13 and13 help with13 collecting13 fish

34

13

III13 Razorback Growth Rates at Bubbling Ponds ndash 2009-shy‐2011

Section13 SummaryExperimental studies at Bubbling Ponds Fish Hatchery AZ have strived to understand

factors that affect razorback sucker growth in captivity and identify ways to improve growthrates and maximize size at release Rather than performing experimental studies that wouldrequire major13 rearrangement (and likely reduced production)13 of hatchery operations our13 studies13 used normal variation in production techniques13 and practices13 to isolate factors13 thatmay modify growth rates

Our initial work identified razorback13 growth rates in13 lined ponds at standard fishdensity as 026 to13 028mmday (789 to 843 mmmonth) No significant differences in growthrate were observed among fish that had been in the pond only during the winter13 periodcompared to fish that had been in the pond the entire year indicating that water temperatures13 at Bubbling Ponds are high enough to allow fish to incorporate feed effectively year-shy‐roundHowever these growth rates are lower than most values reported from the literature fromnatural or semi-shy‐natural pond environments No significant differences in13 growth rate wereobserved13 between large and13 small fish13 within the 150 ndash 29 mm TL13 size range Additional worksuggests13 that razorback suckers13 tagged at over 300 mm TL had reduced growth rates (024mmday 73 mmmonth) as would be expected according to a typical Von13 Bertalanfy growthcurve although growth rates13 were only slightly less13 than the average growth rate for thehatchery (027513 mmday 82513 mmmonth)

Sorting13 to13 separate small fish from large fish after the first year of growth is practicedesigned13 to allow smaller fish to ldquocatch uprdquo to larger fish We found that13 this technique doesappear to13 improve growth rates of smaller fish Growth rates of sorted small razorback suckers(029 mmday 87mmmonth)13 were equal to that13 of larger13 fish (028 mmday 8413 mmmonth)indicating that sorting may have helped to offset their original slower growth trajectory

Bubbling Ponds Fish Hatchery grows razorbacks in 6 long deep ponds lined with heavyplastic 2 long deep13 earthen13 (unlined) ponds and three wide shallow earthen ponds The wideshallow ponds13 have historically produced very large fish at low density but have been found tomaintain much lower fish numbers than deeper ponds We found13 that growth13 rates ofrazorbacks kept at high density (4-shy‐700013 fish)13 in a wide shallow pond grew extremely slowly(024 mmday 726 mmmonth) This growth rate is among the slowest of any fish over theyears of our study and demonstrates that13 though the large ponds may produce large fish at lowdensity13 they are unable to overcome high13 fish13 densities

Finally one of the major factors influencing13 fish13 growth13 in hatcheries is disease onemajor summer-shy‐time disease at13 Bubbling Ponds is the ectoparasite Ich (Ichthiopthirusmultifiliis) To investigate the impact Ich has on razorback growth we eradicated fish from thespring and water conveyance ditch that supplies13 water to the hatchery using Rotenone This13 restoration effort was fairly short-shy‐lived (Ich returned to the hatchery within four months) but

35

13

growth13 rates of fish13 reared for four months without Ich present (031 mmday 92 mmmonth)were significantly higher than the following 8 months of growth for those same fish (022mmday 65 mmmonth) This disease-shy‐free growth rate is in fact faster than any13 otherprevious growth rates observed at the hatchery in our study

We conclude that growth rates at the Bubbling Ponds Fish Hatchery are likely as highas possible given the pond densities required to13 meet production goals and the Ich-shy‐infestedwater13 that feeds the facility Sorting practices are successful in helping as many fish as possiblereach stocking length as fast as possible Unlined ponds may be able to grow large fish at lowdensities but whatever factors allow for that growth13 are not able13 to overcome13 high fish densityThus the large lower ponds at Bubbling Ponds may be better utilized via renovation to13 deepenand line them

Disease is the most important factor limiting growth as may be expected to be the caseat many13 hatcheries While the spring renovation was not13 a complete success13 the dramaticreduction of fish populations in that habitat was enough to dramatically13 reduce13 the13 occurrenceof Ich at the hatchery13 Such open spring13 systems feeding a hatchery are a misfortune that canbe expected to transmit disease so we suggest that renovating the spring again to combat13 IchImproved techniques to divert water from13 the springs and more throuough treatment ofstream-shy‐side vegetation may improve the success of chemical treatment Successful renovationwould likely both improve growth rates and reduce chemical costs associated with treating Ichoutbreaks Even13 if complete renovation13 is impossible or impractical an13 effort to reduceinvasive fish density in the springs13 which act a vector for the parasite(and thereby reduce thelikelihood of13 Ich being transmitted into ponds) may still13 show dramatic improvements

36

13

Introduction

Conservation efforts13 for razorback sucker13 (Xyrauchen texanus)13 currently13 depend on

captive rearing and stocking programs Low survival of stocked razorback suckers (Brooks

1986 Marsh13 and13 Brooks13 1989 Marsh13 and13 Pacey13 2005) has13 caused13 target sizes for stocked13

fish to steadily increase in efforts to reduce predation mortality13 (Marsh13 et al13 2005

Schooley and Marsh 2007) Rearing fish to larger sizes at hatcheries comes with increased

costs and creates the need to evaluate husbandry and rearing practices that may affect fish

growth13 We evaluated growth13 rates13 of individual razorback suckers13 in ponds13 at Bubbling

Ponds Fish Hatchery13 using Passive Integrated13 Transponder (PIT) tags13 to13 obtain13 precise

growth information for individual fish so that valid comparisons of growth rates as related

to rearing practices can be made

Due to the critical nature of the razorback sucker stocking program we did not

design experimental studies that would require major rearrangement and potentially

reduce production of hatchery operations Instead our studies used normal variation in

production techniques and practices to isolate factors that may modify growth rates

Though this methodology dramatically limits replication and may limit our ability to

directly13 attribute13 differences in growth13 rates13 to13 the13 variables13 we13 investigate13 we13 were13 able13

to accomplish research goals without altering hatchery operations or impacting

production

From13 2009 through 2011 we conducted a series of observational13 growth13 studies to

determine growth rates of individual razorbacks at Bubbling Ponds The first set of

experiments included13 identifying13 growth13 rates13 in lined13 and13 unlined13 ponds determining

growth13 rates13 of fish at different13 sizes13 in13 relation13 to sorting13 practices and monitoring

razorback growth rates after removing the source of the ectoparasite13 Ich (Ichthiopthirus

multifiliis) from13 the hatchery water source13

Razorback growth rate in lined ponds

Our first growth study documented individual growth rates at normal density in 11

million gallon lined ponds13 over two13 years13 This is the standard13 grow-shy‐out process for

razorbacks13 at Bubbling Ponds We monitored growth of fish for a variety13 of sizes and13 the13

37

13

amount of time in a pond during the growing season These13 data give a snapshot of growth13

rates13 at the13 facility13 and13 provide13 the basis for comparisons throughout our study

Growth rate13 in an unlined pond

In addition13 to 6 ponds lined with heavy plastic13 sheeting13 Bubbling Ponds Fish13

Hatchery maintains two narrow and deep (same dimensions as lined ponds13 Figure13 4)13 and13

three large13 shallow unlined ponds These earthen13 ponds typically have vegetation and

associated aquatic invertebrates that may better simulate natural environments by

providing cover and improved food diversity or quality Therefore these unlined ponds

may be expected to produce higher growth rates and potentially improved survival that is

more similar to growth rates observed in more natural grow-shy‐out facilities13 Historically13 the13

large13 shallow13 ponds have produced very large fish when13 utilized at low13 fish density13 The

narrow13 deep earthen13 ponds are13 used to grow13 fry13 at high density in their first13 year of life

The major downside to unlined ponds is the difficulty in harvesting fish where a lined

pond might take 8-shy‐1013 people13 a half13 day13 to13 harvest13 lined13 ponds13 require13 intensive13 weeding13

to allow seines to be pulled and therefore require many more personnel-shy‐hours13 In addition13

to harvest challenges the shallow earthen ponds tend to suffer from13 dissolved oxygen

crashes during the summer Unlined ponds also may maintain higher13 populations13 of non-shy‐

target species such as bluegill sunfish mosquito fish and bullfrog tadpoles We measured

growth rates of suckers in a large shallow earthen pond for comparison to growth in lined

ponds13

Figure13 4 Lined13 and13 earthen ponds13 of similar dimensions (approx 1000000 gallons first

and second panels) and a large13 shallow13 earthen13 pond (third panel)

38

13

Effect of sorting on growth

Razorback13 suckers13 are13 currently13 sorted13 after their first13 year of growth13 They are13

typically removed from13 one of the13 upper earthen13 ponds and13 split into13 two13 lined13 ponds for

subsequent grow-shy‐out13 The larger13 fish (gt approximately 140 mm) are placed into one pond

and the smaller individuals in another It is possible that the larger fish were more

aggressive or adept13 at taking food so this sorting process is intended to allow smaller fish

to improve their growth rate

Effect of Ich on razorback sucker growth rates

We13 evaluated13 growth13 rates13 of razorback sucker13 in the13 presence13 and absence of the

ectoparasite13 Ich (Ichthiopthirus multifiliis) Ich outbreaks can occur in wild populations13 but

hatcheries13 have13 proven excellent locations13 for Ich because13 of very high fish densities13 which13

facilitate13 the13 transfer13 of Ich13 between13 fish This common fish parasite causes direct mortality13

to razorback13 suckers as well13 as secondary bacterial13 infections13

The open spring and13 ditch13 which13 provides water to the Bubbling13 Ponds Hatchery

has long13 been infested with mosquitofish (Gambusia affinis) that harbor13 the13 Ich parasite13

and allow13 it13 to enter the hatchery with incoming13 water13 The solution13 to13 the13 Ich problem13

was to remove the mosquitofish host using13 Rotenone Razorback13 sucker growth13 rates were13

then tracked in13 the absence of this parasite for 4 months and compared with growth rates

after Ich returned to the pond and from13 previous years

Methods

Razorback growth rate in lined ponds

On May 14 2008 141 razorback suckers were tagged with 12 mm PIT tags (1342

kHz) and placed in Pond 3 (approximately 1100000 gallons13 Figure13 4)13 at Bubbling13 Ponds

Fish Hatchery Fifty-shy‐three of these tags were recovered two months later when a large

Ichthyophthirius multifilis (Ich) outbreak killed many fish in the pond On October 15 2008

an additional13 145 PIT tagged13 fish were13 also placed into Pond13 3 On13 May13 14 2009 Pond13 3

was harvested and a total13 of 141 PIT tagged fish were recovered13 Of the tagged fish13 26 fish

had13 been13 in the13 pond since May13 of 2008 (378 days13 o growth) and 115 had been13 in13 the

39

13 40

pond since October13 15 2008 (211 days13 of growth) Numbers of fish in Pond 3 after the Ich

outbreak and for the majority of the period of growth were between 3 000 and 4000 fish

A Hobotempreg temperature13 logger13 was13 also13 installed13 in Pond 3 one meter below the water

surface13 near13 the13 outflow and13 recorded water temperature every 3 hours to allow analysis

of the effects of water temperature on growth rate (Figure13 5) This Hobotemp data is

representative of other pond temperatures throughout this study

In a second experiment 210 adult13 razorback suckers13 were13 PIT tagged13 on13 May 14

2009 and13 placed13 into13 Pond13 3 upper to13 evaluate13 growth13 rates13 of larger13 razorback suckers13 at

Bubbling13 Ponds Hatchery13 under current13 rearing13 conditions13 Size of these fish at tagging13

was (mean = 285 mm range = 205 ndash 396 mm) These fish remained in the pond for 257

days and were harvested on Jan 25 2010 to provide information on growth rates of larger

razorback suckers13 under13 current rearing conditions

Figure 513 Temperatures (degC) inrearing pond at BubblingPonds Hatchery from July toSept 2009 (top graph)13 andfrom Nov to Dec 2009 (Lowergraph) Temperaturesrecorded with a Hobotempregremote data logger13 every 3hours

13

Growth rate13 in an unlined pond

To document razorback sucker growth in earthen ponds we introduced13 225 tagged13

razorback suckers13 into13 Pond13 1 lower13 (Figure 4) in February 3 2010 Additional tagged fish

from13 other studies were added to the pond throughout the growing season and the density

of 1 lower reached a maximum13 of nearly 7000 fish in early summer 2010 Density was

reduced to approximately 6000 fish by capturing fish with hoop nets on June 3 2010 54 of

these fish were tagged fish and returned to 1 lower after being weighed and measured The

pond was harvested on January13 2713 2011 and a total13 of 254 tagged fish out13 of 4296 fish

total were removed from13 the pond The pond was harvested on January 27 2011 (358 days13

of growth) and the tagged fish were weighed and measured Total number of razorbacks in

the pond at harvest13 was 4296

Effect of sorting practices on growth rates

On March 1113 200913 Pond13 5 upper was13 harvested13 and13 split into13 two13 separate13 groups

Two hundred of the smaller fish (average size = 122 mm TL) were PIT tagged and placed

into13 Pond13 7 upper and13 200 of the13 larger13 fish (average = 160 mm TL) were PIT tagged and

placed int Pond13 8 upper Density13 in Pond13 7 was13 4500 fish and13 in Pond13 8 there13 were13 6500

fish These ponds were then harvested after 1 year and growth rates were compared to

give information on the effects of current sorting practices Hobotempreg temperature

loggers were installed in13 Ponds 7 and13 8 during13 the13 grow-shy‐out period with13 water13

temperature recorded every 2 hours13 (Figure13 6)

Effect of Ich on razorback sucker growth rates

Bubbling Ponds spring was treated with Rotenone (CFT Legumine 5) at a

concentration of 2 ppm13 to remove all mosquitofish from13 the spring The treatment

consisted of two treatments 6 hours in duration on two consecutive days (April 12 -shy‐ 13)

using13 drip13 stations13 and13 backpack sprayers13 followed13 by13 an13 additional 6 hours13 of

detoxification using sodium13 permanganate Although 12 mosquitofish were captured in the

spring pond the week following the treatments subsequent minnow trapping (20 traps

checked13 daily13 for 3 weeks) did not capture any additional fish until August 11 2010 when

41

13

juvenile mosquitofish were again detected in the spring pond Minnow traps have

subsequently been set daily with several hundred individuals removed To evaluate if Ich

was also again present in the spring we captured 15 mosquitofish from13 the spring pond on

three separate days and placed them13 in an aquaria at 25 degC with 5 longfin dace known to be

free of Ich These fish were monitored for 2 weeks with no signs of Ich developing This

indicates that even though mosquitofish have returned to the spring pond the parasite is no

longer present13 although how13 long13 this condition13 will13 persist13 is unknown13

On May 1113 201013 200 juvenile razorback13 suckers were harvested out13 of Pond 5

upper (2009 year Class from13 Dexter National Fish Hatchery) and were PIT tagged and

placed into Pond 8 to evaluate if growth rates at bubbling ponds hatchery have improved

following the renovation of the spring and the removal of the Ich parasite Unfortunately13

on Sept13 8 2010 Ich was13 again13 detected13 in Pond 8 and the pond was immediately seined

and 74 tagged fish were measured to obtain growth information for the 4-shy‐month period

during13 which13 the13 pond13 was13 Ich-shy‐free13

Figure13 6 Temperatures (degC) in rearingponds 7 and 8 at Bubbling Ponds Hatchery13 from March 2009 ndash March 201013 pond 7(top13 graph)13 and13 pond 8 (Lower13 graph)13 Temperatures recorded with a Hobotempregremote data logger every 3 hours

42

13

Results

Growth in Lined Ponds

Razorback suckers13 that had been13 in13 Pond 8 upper for the13 entire13 year13 grew an13

average of 0263 mmday (789 mmmonth) and razorback suckers that had been in the

pond for 7 months (Oct -shy‐ May) grew13 on13 average of 028 mmday (843 mmmonth) (Figure13

7) These growth13 rates13 did not significantly13 differ Fish density13 in Pond 3 during13 the13

majority of the growth period was13 00032 ndash 00036 fishgallon13 Additionally no13 significant

differences in growth rate were observed between fish smaller than 210 mm TL and fish

larger than 210 mm TL when all recaptured fish were combined

We also measured the growth rate of very large fish in a lined pond On Jan13 2513 201013

156 adult fish with PIT tags were recovered from13 Pond 3 upper13 These fish were13 in the13

pond for 257 days and experienced an average13 growth13 rate13 of 024mmday or 73

mmmonth (Figure13 7)13 This growth13 rate13 is slightly13 lower13 than13 the13 average13 growth13 rate13

observed13 at Bubbling13 Ponds Hatchery in other studies (0275 mmday 825 mmmonth)

but may not be biologically meaningful We would expect larger13 fish to13 have13 reduced

growth rates according to a typical Von Bertalanfy growth model (Bertalanffy 1957) but it

appears that13 over the size range we evaluated (300 -shy‐ 450 mm TL) growth rates have not

slowed significantly compared to that of smaller13 fish grown at Bubbling Ponds13 Hatchery

Growth13 of razorback suckers13 is known13 to13 slow as13 fish reach13 larger13 sizes but it appears13 this13

reduced growth rate may not really start to be biologically meaningful at Bubbling Ponds

Hatchery13 until razorback suckers13 exceed 450 mm TL

Growth in unlined ponds

Growth13 rates13 for the13 fish recaptured13 during13 the Pond 1 lower13 thinning13 (120 days13 in

the pond) was 024 plusmn 003 mmday (729 plusmn 090 mmmonth) (Figure13 8)13 Fish13 that were13 in

the pond for nearly the entire year grew13 an13 average13 of 024 plusmn 001 mmday (726 plusmn 027

mmmonth) These growth rates are surprisingly the lowest measured growth rates for

any part of our study and differ significantly from13 every other measured growth rate

except very large13 fish (Figure13 9)13 Separating13 out13 large fish that13 were in13 the pond for the

entire year makes no difference fish that were added to the pond at TL lt300 mm grew

43

13

Gro

wth

Rat

e (m

md

ay)

020

026

032

0244 plusmn 001 mmday (733 plusmn 028 mmmonth) and and those with TL gt= 300 mm at the

start of the experiment grew 022 plusmn 003 mmday (651 plusmn 101 mmmonth)

Razorback Growth Rates in Lined Ponds

Figure 7 Growth ofrazorback suckers in(mmday plusmn standard error)in Pond 8 upper in 2008-shy‐2009 An ANOVA did notdetect any significantdifferences

7 Months Full Year 300+ mm fish

Effects of sorting on growth

One hundred and seventy five tagged razorback suckers were recovered from13 Pond

8 upper13 on March13 24 2010 (378 days13 of growth)13 These were13 the13 larger sorted13 fish (gt140

mm TL) that came out of Pond13 5 on March13 11 2009 One13 hundred and13 twenty13 two13 tagged13

razorback suckers were also recovered from13 Pond13 7 upper on March13 31 2010 (385 days13 of

growth)13 These were13 the13 smaller sorted13 fish (lt140 mm TL) that came out of Pond13 5 on

March 1113 200913 No significant differences in growth rate (mmday) were observed among

larger fish in Pond 8 and smaller fish in Pond 7 (pgt005 ANOVA) (Figure 10)13 indicating

that13 sorting may have helped to offset the original slower growth trajectory of the smaller

fish Temperatures of Ponds 7 and 8 upper remained similar throughout the year13 (Figure

5)

44

13

13

13

Gro

wth

Rat

e (m

md

ay)

Gro

wth

Rat

e (m

md

ay)

020

026

032

020

026

032

Razorback Growth in an Unlined Pond

Figure 8 Growth of razorbacksuckers (mmday plusmn standard error) in Pond 1 lower (an unlined pond)in 2010-shy‐2011 An ANOVA did notdetect any significant differences

6 Months 12 Months lt 300 mm Fish 300+ mm Fish Growth Growth

Lined vs Earthen Ponds 1 year of growth

Figure 9 Growth of razorbacksuckers (mmday plusmn standard error) in lined and unlined ponds A t-shy‐test13 did not detect a significantdifference

Lined Pond Unlined Pond 1 Yr Growth 1 Yr Growth

45

13

Effect of Sorting G

row

th R

ate

(mm

day

) G

row

th R

ate

(mm

day

)

032

020

026

032

020

026

Smaller Fish Larger Fish

Effect of Ich

Figure 10 Average growthof razorback suckers(mmday plusmn standard error)that were size-shy‐sorted intosmall fish (pond 7) and largefish (pond 8) populations At-shy‐test did not detect asignificant difference

Figure 11 Average growth ofrazorback suckers (mmday plusmnstandard error) after Ich wasremovd from the hatcheryrsquos springand after Ich was again detected inthe pond The growth rate withoutIch is significantly higher than boththe rate after Ich and the ourstudyrsquos average annual growth ratein lined ponds (ANOVA p =00003)

Growth without Ich Growth With Ich Average Annual 4 months 4 months Growth Rate

46

13

Effect of Ich on razorback sucker growth rates

Seventy-shy‐four13 tagged13 razorback suckers13 were13 recovered from13 Pond 8 on September

15 2010 These fish had13 been13 in the pond for 4 months and experienced a growth rate of

032 mmday or 97 mmmonth (Figure13 11)13 This growth13 rate13 is significantly higher (p =

005 two sample t-shy‐test) than the mean growth rate for the same group13 of tagged fish after

Ich detection (022 mmday or 65 mmmonth) and significantly higher than any other

individual growth13 rates13 observed13 to13 date13 at Bubbling13 Ponds Hatchery13 (Figure13 11)13 If this13

growth13 rate13 were13 extended throughout13 the entire13 year13 fish on average from13 Ich-shy‐free13 ponds13

would be 16 mm longer than fish from13 ponds infested with Ich Studies conducted at

Bubbling Ponds hatchery in 2008 (Ward 2008) did not reveal any effects of the treatment

chemicals on razorback sucker growth rates so it13 is likely that13 the parasite outbreaks

themselves are causing reducing growth rates rather than the chemicals used to treat the

parasites13

Conclusions

Our results suggest that under typical hatchery operations (maximizing number of

fish produced)13 the growth13 rate13 of razorback13 suckers13 is relatively13 consistent at Bubbling13

Ponds hatchery13 at 02-shy‐03 mmday (6-shy‐9 mmmonth)13 but is lower than growth13 rates13 at

other13 facilities (02 ndash 18 mmday Ward et al 2007)13 This growth13 rate13 has13 been13 constant in

both lined and unlined ponds and at all fish densities we were able to measure To achieve13

growth13 rates13 substantially higher than this will likely require13 significant changes in rearing

practices that may not be practical in order to reach numerical production13 goals

Temperature is a key variable in fish growth but seasonal growth patterns

described13 above13 (Figure13 5) demonstrate that water temperatures are high enough in

winter to maintain razorback growth Differences in water temperature by season

currently13 do not fluctuate more than 10degC at Bubbling Ponds because of the continuous

supply of water flowing through each pond (approx 225 gallonsmin) These high water

flows appear to keep pond temperatures within the thermal preference13 for razorback

suckers13 (1213 -shy‐ 28 degC Bulkley and Pimentel 1983) throughout the entire year with

temperatures rarely dropping13 below 16deg13 C (Figures 513 6)13

47

13

Fish density is another key variable in fish growth and though the number of fish in

a pond during our study ranged from13 3000 to 700013 fish we13 did not find any13 correlation13

between13 density and growth rate13 This might yield two conclusions First13 razorback

growth13 may be changed equally13 by13 densities13 at the13 hatchery13 (ie13 a density13 of 3000 fish in a

pond is as stressful13 for razorbacks as a density13 of 7000 fish) An alternative is that other

factors13 such as disease outbreaks have13 stronger13 control over fish growth13 than13 density13

Fish density13 would13 have13 to13 be13 experimentally manipulated to test13 this13 and hatchery

operations (producing the maximum13 number of fish) prevented our manipulating density13

in ponds for this13 work The trouble with manipulating density demonstrates the difficulties

associated with changing13 hatchery13 practices experimenting with density would have

prevented BPH from13 meeting13 production13 goals Given that the stocking of smaller

razorbacks has met with very little success perhaps BPH goals could be changed from13

producing 12000 fish at 300+ mm per year to a smaller number of very large fish each

year Growing13 fewer13 larger13 fish could potentially be accomplished in the same time frame

as more smaller fish but a better understanding of how density alters growth rate would

be required to be confident13 of this

The very slow growth13 in the13 earthen13 unlined13 Pond 1 lower13 was very surprising We13

had13 anticipated13 that the13 diversified diet13 cover and13 other13 habitat features13 provided by13

unlined ponds would yield dramatically increased growth rates However these traits were

not enough to offset high fish densities and in fact the unlined pond in our study13 suffered

mortality to bring densities down to that observed normally in lined ponds

Our data13 suggest13 that razorbacks13 sucker13 growth13 rates13 are13 higher in lined13 ponds13

However we13 think the reasons13 for the13 very slow growth we observed13 in the13 unlined13 pond13

in our study13 is instead13 linked13 to13 the13 usage13 of Pond 1 lower13 during13 the13 study13 rather13 than13

intrinsic13 slow growth13 in earthen13 ponds First the pond was at extremely high density for at

least part of the study The volume of Pond 1 lower has not been estimated but hatchery

managers suggest 1500-shy‐2000 fish is an appropriate number of individuals so this pond

was at a very high density for much of the experiment Second dissolved oxygen is often

very low in the13 large13 earthen13 ponds during the heat of summer much lower than that of

lined ponds This will both limit the number of fish that can survive in the pond and almost

certainly13 increases stress13 of these13 fish potentially13 reducing growth13 The DO crashes also13

48

13

limit the amount of feed hatchery managers can give fish in these ponds sometimes for

days or weeks at a time which further reduces growth during warm13 weather

Our data13 suggests that13 growth rates at the Bubbling13 Ponds Fish Hatchery are likely

as high as possible given13 the pond densities required to meet production goals and the Ich-shy‐

infested water that feeds the facility Sorting practices are successful in helping as many

fish as possible reach stocking length as fast as possible Unlined ponds may be able to

grow13 large13 fish at low13 densities13 but whatever factors allow13 for that13 growth are not13 able to

overcome high fish density The removal of invasive13 fis that act as13 a host for the13 parasite13

Ich fish from13 the Bubbling13 Ponds spring13 allowed the highest13 growth rate at 032 mmday13

(96 mmmonth) but that growth rate decreased again as Ich re-shy‐infested13 the13 hatchery13

Consistently13 achieving13 growth13 rates13 as high or substantially13 higher than13 this13 will likely13

require13 significant changes in rearing practices that may not be practical in order to13 reach13

numerical production13 goals

Two major changes that might result in higher growth rates are substantially

reducing fish density and modifying the way spring water is delivered to the facility (via

either repeated chemical treatments or enclosed concrete water diversions) to eliminate

Ich from13 the hatchery source water Other potential changes not address by our work

include13 flow-shy‐training razorbacks much previous literature including MSCP-shy‐funded13 work

on razorback suckers13 suggests13 that fish growing13 in flowing water will grow13 faster than fish

in still water (Jorgensen and Jobling 1994) Furthermore there are a wide variety of

potential benefits associated with growing13 fish13 in flowing13 water in addition13 to increased

growth13 rates13 (Davidson13 199713 Castro13 et al13 2011) Another option13 for increasing13 growth13

rates13 include13 changing to13 intensive13 culture13 in large circular13 tanks

Finally given that the stocking of smaller razorbacks has met with very little

success13 perhaps13 BPH13 goals13 could13 be13 changed from13 producing 12000 fish at 300+ mm per

year to a smaller number of very large fish each year Growing fewer larger fish could

potentially be accomplished in the same time frame as more smaller fish but a better

understanding13 of how density13 alters growth13 rate13 would13 be13 required to13 be13 confident of this

49

13

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower13 Colorado13 River Multi-shy‐Species13

Conservation Program13 (LCRMSCP) under Work Task C10 We13 thank Ty Wolters13 Tom13

Burke13 and Eric13 Volkman for their support of this research and Frank Agygos and Dave

Billingsly13 of the Bubbling13 Ponds Fish Hatchery13 for their willingness to participate in13 this

research13 and13 for their technical assistance We also thank the LCRMSCP fish group from13

Boulder City13 NV for their assistance with harvesting13 ponds and tagging13 fish13

50

13

Literature13 CitedAnders P J 1998 Conservation aquaculture and endangered species can objective science13

prevail13 over risk13 anxiety Fisheries 23(11) 28-shy‐31

Anderson R O and R M Nuemann 1996 Length weight and associated structural indicesPages 447 ndash 482 in B R Murphy13 and D13 W Willis13 editors13 Fisheries techniques13 2ndedtion American Fisheries13 Society13 Bethesda13 Maryland

Bain M B J T Finn and H E Brooks 1988 Streamflow regulation and fish communitystructure13 Ecology13 69382-shy‐392

Bays J H Zarbock R Whitman and T Murphy 2005 Conceptual design and managementof native13 fish refugia on the13 lower13 Colorado13 River In13 CL Spring13 and13 S Leoneditors Proceedings of two symposia Restoring native fish to the lower ColoradoRiver13 interactions13 of native and non-shy‐native13 fishes 13ndash1413 July13 1999 Las13 Vegas13 Nevada13 Restoring13 natural function within a modified riverine environment thelower Colorado River13 8ndash913 July13 1998 U S Fish and13 Wildlife13 Service Southwestern13 Region Albuquerque New Mexico Pages 167-shy‐177

Bertalanffy L Von 1957 Quantitative laws in metabolism13 and growth13 Q Rev Biology 32217 ndash 231

Bingham T B Scheer and C McAda 2003 Propagation facilities in Grand Valley (24 RoadHatchery Horsethief13 Ponds and13 grow-shy‐out ponds) for captive13 rearing13 ofendangered13 fishes for the13 upper13 Colorado13 River basin13 Colorado River RecoveryProgram FY2003 annual project report13 US Fish and13 Wildlife13 Service GrandJunction13 4pp

Birchell G J and K Christopherson 2004 Survival growth and recruitment of larval andjuvenile razorback13 sucker (Xyrauchen texanus) introduced13 into13 floodplain13 depressions13 of the13 Green River Utah13 Final report13 Upper13 Colorado13 RiverEndangered Fish Recovery Program13 Project No C-shy‐6RZ Publication Number 04-shy‐1513 Utah13 Division of Wildlife13 Resources Salt Lake13 City13 Utah13 67 pages

Brannon E L 1993 The perpetual oversight of hatchery programs Fishery Research 1819-shy‐27

Brett J R 1979 Environmental Factors and growth pages 599-shy‐67513 InW S Hoar13 D13 J13 Randall and J R Brett (eds) Fish Physiology Volume 8 Bioenergetics and GrowthAcademic Press New York

Brooks J E 1986 Annual reintroduction and monitoring report for razorback suckerXyrauchen texanus in the Gila River Basin Arizona 1985 US Fish and WildlifeService13 Offices of Endangered13 Species and Fishery13 Resources Albuquerque 23 pp

51

13

Brunson13 R E and K D13 Christopherson13 200513 Larval13 razorback13 sucker and bonytailsurvival and13 growth13 in the13 presence13 of nonnative13 fish in the13 Baeser13 floodplainwetland of the middle Green River Final report prepared for Upper13 Colorado RiverBasin Endangered Fish Recovery Program Project No C-shy‐6-shy‐rz-shy‐bt Publication13 No 05-shy‐26 Utah13 Division of Wildlife13 Resources13 Vernal13 32 pp

Bulkley R V and R Pimentel 1983 Temperature preference and avoidance by adultrazorback suckers Transactions of the American Fisheries Society 112601-shy‐607

Burke13 T13 199513 Rearing13 wild razorback13 sucker larvae in13 lake-shy‐side13 backwaters13 LakeMohave ArizonaNevada Proceedings of the Desert Fishes Council 2635

Busacker G P I R Adelman and E M Goolish13 199013 Growth13 Pages 363 ndash 387 in C BSchreck and p B Moyle editors Methods for fish biology American FisheriesSociety Bethesda Maryland

Castro V B Grisdale-shy‐Helland S J Helland T Kristensen S M Jorgensen J Helgrud13 GClaireaux A P Farrell A Krasnov and H Takle 2011 Aerobic training stimulatesgrowth and promotes disease resistance in Atlantic salmon (Salmo salar)Comparative Biochemistry and Physiology -shy‐ Part A Molecular amp IntegrativePhysiology13 160(2) 278-shy‐290

Czapla T E 2002 Facilities plan for the production of endangered fishes to meet statestocking13 plans13 as13 part of the13 Upper13 Colorado13 River Endangered13 Fish RecoveryProgram Upper Colorado River Basin Recovery Implementation Program US Fishand Wildlife Service13 Denver13 9 pp

Davidson W 1997 The effects13 of exercise13 training on teleost fish a review of recentliterature Comput Biochem Physiol 117A67ndash75

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Gerking13 S D 1978 Ecology of freshwater fish13 production13 Halstead Press13 New13 York

Gustafson W and Q Bradwisch 2000 Wahweap operation and maintenance -shy‐-shy‐ UtahColorado River Recovery Program FY 2000 annual project report Project No 29cUtah13 Division of Wildlife13 Resources Page AZ 3pp

52

13

Hamman R L 1985 Induced spawning of hatchery-shy‐reared13 razorback sucker ProgressivFish Culturist 47(3) 187-shy‐189

Hanson J N 1996 Annual report fiscal year 1996 Willow Beach National Fish HatcheryUS Fish and Wildlife Service13 Willow Beach 9pp

Irving D S Seversen and M Montagne 2004 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2004 annual project13 report Report No 29b US Fish and13 Wildlife13 Service Vernal 3pp

Jorgensen E H and13 M Jobling 1994 Feeding and13 growth13 of exercised13 and13 unexercised13 juvenile Atlantic salmon in freshwater and performance after transfer to seawaterAquaculture International 2 154-shy‐164

Kaeding L R and D B Osmundson 198913 Colorado13 Squawfish13 and13 razorback sucker grow-shy‐out pond studies as part of conservation measures for the green mountain andRuedi reservoir water sales Final report for agreement number 6-shy‐AA-shy‐60-shy‐00150

Koebele13 B P13 198513 Growth and the size hierarchy effect an experimental assessment ofthree proposed mechanisms activity differences disproportional food acquisition13 pysiological stress Environmental Biology of Fishes 12 181-shy‐188

Kretschmann A E and L L Leslie 2006 Razorback sucker (Xyrauchen texanus) status13 reproduction and recruitment in Senator Wash Reservoir CA Final Report13 to USBurea of Reclamation Cooperative Agreement No 00-shy‐FG-shy‐34-shy‐ 0009 p 32 ArizonaGame and Fish Department Phoenix

Marsh13 P13 C13 1987a13 Digestive tract13 contents13 of adult razorback suckers13 in Lake13 MohaveArizona-shy‐Nevada Transactions of the American Fisheries Society 116117-shy‐119

Marsh P C 1987b Native fishes at Buenos Aires National Wildlife Refuge and ArizonaState University Research Park Arizona opportunities for management researchand public13 education13 on13 endangered species13 Proceedings of the Desert13 FishesCouncil 1967-shy‐78

Marsh P C 1994 Rearing native Colorado River fishes in golf course ponds Arizona StateUniversity Tempe 22 + pages

Marsh13 P13 C13 200013 Fish population13 status and evaluation13 in13 the Cibola13 High Levee PondFinal report agreement number 99-shy‐FG-shy‐30-shy‐00051 US Bureau of ReclamationBoulder City13 Nevada13 20 pages

Marsh P C and C A Pacey 1998 Growth of wild adult razorback suckers13 in Lake13 Mohave13 Arizona-shy‐Nevada13 Final report13 US Bureau of Reclamation Boulder City Nevada 25pages + appendices

53

13

Marsh P C B R Kesner and C A Pacey 2005 Repatriation as s management strategy13 to13 conserve a critically13 imperiled fish species North American Journal of FisheriesManagement 25 547-shy‐556

Marsh P C and C A Pacey 2005 Immiscibility of native and non-shy‐native13 fishes Pages 59-shy‐63 inMJ13 Brouder13 CL13 Springer13 and CS13 Leon13 editors13 Proceedings of two13 symposia Restoring native fish to the lower Colorado River interactions of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 NV and13 Restoring natural13 function within a modified riverine environment the lower Colorado River13 July13 8-shy‐913 1998 Las Vegas NV US Fish and13 Wildlife13 Service Southwest Region AlbuquerqueNew Mexico

Marsh13 P13 C13 and J13 E Brooks13 198913 Predation13 by ictalurid catfishes as a deterrent13 toreestablishment of hatchery-shy‐reared13 razorback sucker The Southwestern Naturalist34188-shy‐195

Matthews R A 2005 Ichthyopthirus multifiliis Fouquet and Ichthyopthirosis infreshwater13 teleosts13 Pages13 159-shy‐218 in Advances in Parasitology volume 59 J RBaker R Muller D Rollinson (eds) Academic Press

McCarthy13 M S and W L Minckley 1987 Age estimation for razorback sucker (PiscesCatostomidae) from13 Lake Mohave Arizona and Nevada Journal of the Arizona-shy‐Nevada Academy of Science 2187-shy‐97

Minckley13 W L13 198313 Status of the razorback13 sucker13 Xyrauchen texanus (Abbot)13 in13 thelower Colorado River basin13 The Southwestern13 Naturalist13 28(2) 165-shy‐187

Minckley13 W L13 199113 Native fished of the Grand Canyon13 region an obituary13 Pages 124-shy‐177 in Colorado River ecology and dam13 management National Academy PressWashington13 DC

Minckley13 C13 O and M LaBarbara13 199913 Report13 on13 native fish grow-shy‐out facilities13 at Cibolaand Imperial National Wildlife Refuges 1993-shy‐199513 US Fish and13 Wildlife Service13 Parker Fishery Resources Office Parker Arizona

Modde13 T13 199613 Juvenile razorback sucker (Xyrauchen texanus) in a managed wetlandadjacent13 to the Green13 River13 Great13 Basin13 Naturalist13 56375-shy‐376

Modde T KP Burnham and E J Wick 1996 Population status of the razorback sucker13 inthe middle Green River (USA) Conservation13 biology 10 110-shy‐119

Modde13 T13 and G13 B Haines13 200513 Survival13 and growth of stocked razorback13 sucker andbonytail in multiple floodplain wetlands of the middle Green River under resetconditions13 Final report prepared for Upper Colorado13 River13 Basin RecoveryImplimentation Program US Fish and Wildlife Service Vernal 66 pp

54

13

Modde T Z H Bowen and D C Kitcheyan 2005 Spatial and temporal use of a spawning13 site in the middle Green River by wild hatchery-shy‐reared13 razorback suckers13 Transactions of the American Fisheries Society 134937-shy‐944

Mueller13 G13 199213 The native fish work13 group13 -shy‐ a multiagency endeavor to improve thestatus of the razorback sucker in Lake Mohave AZ-shy‐NV13 Proceedings of the DesertFishes Council 2369

Mueller G 1995 A program13 for maintaining the razorback sucker in Lake MohaveAmerican Fisheries Society Symposium 15127-shy‐135

Mueller13 G13 200613 Ecology of the bonytail13 and razorback13 sucker and the role of offchannelhabitats13 in their13 recovery Scientific13 investigations13 report 2006-shy‐5065 US GeologicalSurvey13 Denver

Mueller G and E Wick 1998 Testing of golf course ponds at Page Arizona for suitability13 as grow-shy‐out facility for razorback sucker using surplus fish from13 Ouray NationalFish Hatchery National Park Service US Fish and13 Wildlife13 Service and UtahDivision of Wildlife13 Resources 28 pages

Mueller13 G13 and T13 Burke13 200513 Survival13 of young13 razorback13 sucker (Xyrauchen texanus) inrelation to13 stocking rates13 (fishha)13 and13 in the presence13 or absence13 of predatorcommunities in Lake Mohave Arizona-shy‐Nevada13 Pages13 155-shy‐16313 in Proceedings of two13 symposia restoring native fish to the lower Colorado River interaction13 of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 Nevada US Fish and Wildlife13 Service Southwest Region Albuquerque New Mexico

Mueller13 G13 J13 Carpenter13 and P13 C13 Marsh13 200413 Cibola13 High Levee Pond annual report 2004US Geological Survey Fort Collins13 Science Center13 Colorado13 and Arizona StateUniversity Tempe 23 pages

Nesler T P K Christopherson J M Hudson C W McAda F Pfeifer and T E Czapla 2003An integrated stocking plan for razorback sucker bonytail and Colorado13 pikeminnow for the Upper Colorado River Endangered Fish Recovery ProgramAddendum13 to State Stocking Plans Upper Colorado River Basin Recovery13 Implementation Program 12 pp

Papoulias13 D and W13 L Minckley13 1992 Effects13 of foo availability13 on survival and growth13 of larval razorback suckers13 in ponds Transactions of the American Fisheries Society121340-shy‐355

Paukert13 C P D L Ward13 P J Sponholtz13 and K13 D Hilwig13 Effects13 of repeated hoopnetting13 on bonytail chub13 Journal of Freshwater13 Ecology13 20(4) 649-shy‐653

Pfeifer F M13 C Baker13 and M13 Montagne13 199913 Propagation13 facilities13 in the13 Grand Valley13 (24 Road13 Hatchery13 Horsethief13 Ponds and13 grow-shy‐out ponds) for captive rearing of

55

13

endangered13 fishes for the13 Upper Colorado13 River Basin13 Colorado13 River Recovery13 Program FY 99 annual project report Project No 29a13 US Fish and Wildlife Service13 Grand13 Junction13 5pp

Pfeifer F S Seversen and M Montagne 2003 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2003 annual reportProject No 29b13 US Fish and Wildlife13 Service Vernal13 4pp

Rabago-shy‐Castro J L Sanchez13 J G Perez-shy‐Castaneda R and13 Gonzalez-shy‐Gonzlez A 2006Effects of the prophylactic use of Romet-shy‐3013 and13 copper13 sulfate13 on growth13 condition13 and feeding13 indicies in13 channel13 catfish (Ictalurus punctatus) Aquaculture 253 343-shy‐349

Reinitz GL L E Orme and F N Hitzel 1979 Variations of body compositio and growth13 among strains of rainbow trout Transactions of the American Fisheries Society 108204-shy‐207

Ruppert13 J13 B P B Holden13 and P D Abate 1999 Age estimation and growth of razorbacksucker13 Xyrauchen texanus in Lake13 Mead Nevada Proceedings13 of the Desert FishesCouncil 3040

Schnoor K D and J Logan 2002 Operation and maintenance of JW Mumma nativeaquatic13 species restoration facility Colorado Colorado River Recovery Program FY2002 annual project report13 Project No 29d Colorado13 Division of Wildlife Alamosa3pp

Salisbury13 L13 1998 Factors13 affecting razorback13 sucker growth13 in Lake13 Mohave backwaters13 MS Thesis13 Unviersity13 of Nevada13 Las13 Vegas

Schooley J13 D13 and P C13 Marsh13 2007 Stocking of endangerdd13 razorback13 suckers13 in thelower Colorado River Basin13 over three decades 1974-shy‐2004 North American Journalof Fisheries Management 27 43-shy‐51

Severson S H H M Tyus and G B Haines 1992 An evaluation of feeds for raisingrazorback sucker Xyrauchen texanus Journal of Applied Aquaculture 155-shy‐65

Toney D P 1974 Observations13 on the13 propagation13 and13 rearing13 of two13 endangered species13 in a hatchery environment Proceedings of the Annual Conference of the Western13 Association of State Game and Fish Commissions 54 252-shy‐259

Tyus H M13 1998 Razorback sucker13 (Xyrauchen texanus) recovery plan13 University13 ofColorado Center for Limnology Boulder13 76 pages

Tyus H M13 and13 S H Severson 1990 Growth13 and13 survival of larval razorback suckers fedfive formulated diets The Progressive Fish Culturist 52197-shy‐200

56

13

Ulibarri M E 2003 Annual report fiscal year 2001 Dexter National Fish Hatchery13 andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 26 pages

Ulibarri M E 2003 Annual report fiscal year 2002 Dexter National Fish Hatchery andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 59 pages

USBR 2006 Lower13 Colorado13 River Multi-shy‐Species Conservation Program final fishaugmentation plan Boulder City 19 pp

USFWS 2002 Razorback sucker (Xyraouchen texanus) recovery goals Amendment andsupplement to the Razorback Sucker Recovery Plan13 US Fish and Wildlife Service13 Region 6 Denver13 Colorado

USFWS 1999 Annual report 1999 Ouray National Fish Hatchery Vernal 25pp

USFWS 2004 Management plan for the big-shy‐river13 fishes of the13 lower13 Colorado13 river basinamendment and supplement to the bonytail humpback chub Coloradopikeminnow and razorback sucker recovery plans

USFWS13 2005 Station13 profile13 of the13 Dexter13 National Fish Hatchery13 and Technology CenterUS Fish and Wildlife13 Service Dexter

Valdez R A P G Mangan R Smith and B Nilson 1982 Upper Colorado River fisheriesinvestigations13 inW H Miller J J Valentine D L Archer H M Tyus R A Valdezand L13 Kaeding13 editors13 Colorado River Fishery13 Project13 Part 2 Field13 investigations13 US Bureau of Reclamation Salt Lake City Utah

WBNFH 2004 Culture methods of the endangered razorback sucker Xyrauchen texanusUS Fish and Wildlife13 Service Willow Beach National Fish Hatchery13 8 pp

Ward D 2008 Effects of disease treatments on growth of razorback sucker ReportSubmitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 Inpartial fulfillment of work task C10 agreement number 06FG30039

Ward13 D13 M Childs and W Persons 2007 Factors13 affecting13 growth13 of razorback sucker13 (Xyrauchen texanus) in captivity Literature review and knowledge assessmentReport Submitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 In partial fulfillment of work task C10 agreement number 06FG30039

57

Appendices

Appendix 1 Survey Questions Survey of Razorback Sucker Culture in the

Southwestern United States

The enclosed survey is being distributed by the Arizona Game and Fish Department to razorback sucker culture facilities throughout

the Southwestern United States The purpose of this survey is to consolidate information regarding culture of this species so that

appropriate facility improvements can be considered for Bubbling Ponds Hatchery in Arizona Specifically we wish to increase

growth rate and production efficiency at the hatchery Information gathered in this survey will be summarized in a final report to US

Bureau of Reclamation in Boulder City NV and disseminated to all facilities that participate in the survey A workshop to discuss

the findings of this study as well as to share general information concerning razorback sucker culture will be organized by the

Arizona Game and Fish Department at the conclusion of this study and all participants will be invited

Thank you for taking the time to fill out this survey Please contact Mike Childs if you have questions or would like to discuss the

survey

Mike Childs

mchildssedonanet

(928) 639-1346

(928) 634-1279

Facility_____________________________________ Date___________________

Contact Phone _____________________________

ContactPerson_______________________________

Contact Email _______________________________

1 Water quality ranges at this culture facility

Season

Spring (Mar-May) Summer (Jun-Aug) Fall (Sept-Nov) Winter (Dec-Feb)

Temperature (C)

PH

DO (mgL)

PO4 (mgL)

TDS (mgL)

Hardness (mgL)

CaCO3

Pathogens

37

13

Table13 6 Rearing13 practices13 that are13 unique to13 specific rearing13 facilities13 $$amp( )$+-(amp$-(0(1-amp2034( $amp()amp+( -0$(12(33+(amp(amp134$53+(amp$amp3+(6amp+(

723(843(1$8(422(6amp+(42amp(4(423(19$43( 343( lt34$53(6amp+(6(4($03(amp4+94amp(842($1$1(63$$34(amp+(63626243( =amp+(gtamp94ampA( B3(1(1$+53+C3+(amp+(1$43(1(3D0$(1(amp443(amp+(amp443( 734231(amp( B3(1(193(44(1(34amp(amp(+49E(6amp+( -E3(F3+( G3amp(1(12(amp(H3(13$(4ampE(C(IJK($$amp( A( L43(+A3(4(6303amp4(63+4ampM(66$3D3amp4$(34amp(amp(6amp+(C((4amp3( L$$8(392(

B0$+3(

N43D(13+(4($0$(12M(amp+(639$53+($0$(12(+34( G3amp(12(amp(399$4amp(4+(938A(842($(2343+(843( N443D643+(3amp(12(amp(amp34(63amp(amp(423(O$+(G03( )amp+(3(134$53+(6(4(39364(1(1A(4(44(423D(amp((D3(amp4$(+34(

Table13 7 Types of feed used at razorback sucker13 hatcheries13 $amp ()amp+-amp0- $$)1amp23 45-amp)-$5)1amp23 $amp()amp+( -amp$amp+(amp+( -amp012$3+(amp+4(amp5215$(0+( 65ampamp7(85209(+2($1(87((15315lt=(+2(

+amp+amp(amp(55$5$2gt( 21( Aamp+(amp+( )amp+(012$3+(B29(5$05$95($$2(5amp+(

199524(amp5215$(0+( 65ampamp7(85209(+2($1(87(15315lt=(+2(amplt( 29gt(51($51(amp9(2(25=(C(DD(0+(

E15amp+(Famplt2amp( G1$5(lt1lt$51(25amp=( HIJKH(Dlt1amp(15315lt=(+2(I(C2(CH(+5gt( )11$gt($511(02+(15315lt=(+2(

$1(87(15315lt=(+2(D5$$(3(lt5$$gt(02+(gt( 6lt=(511B(

L15gt( G1$5(lt1lt$51(25amp=(Aamp+( amp+(

HIJKH(Dlt1amp(15315lt=(+2(I(C2(CH(+5gt( )11$gt($511(02+(15315lt=(+2(

$1(87(15315lt=(+2($1(87($B(amp=amp( 5$Damp(+2(

M$$B(5lt9(-5$+( NO515(G1$5(219( L2+1(15ltB5gt(Aamp+(5amp+( amp$amp+(amp+(

1amp(91D(amp5$(Pamplt5$amp4( 8gtlt$34(1$amp54(5amp+(5120lt5$( $5amp=2amp()amp+(012$3+(B29(5$05$95( $$2(5amp+(19952Q(amp12152( 1+lt2amp(

$1(87(15315lt=(+2($1(87(15315lt=(+2( $1(87(15315lt=(+2(

Table 8 Factors limiting production at major razorback sucker facilities

$amp( )amp+(-0+1((2$(0amp1ampamp(-34amp( $amp()amp+( -(01$2(34+(546(amp(0amp(01amp(541(13( -741( 803(3amp41amp4(9((+ltlt1amp4(03(amp(44amp(2=(4(

+ltlt3$4(4(2amp4amp(014(1gt13=(43=( 1amp+(amp34amp( 803(3amp41amp4(1$4+(4(541(A$4B(amp+(+$C+(

7Bamp($244amp(lt(1313$4amp(B42( D1B( E41(A$4B(01$2(3+(B(66(1amp(amp+(2ampamp(

Eamp41(420141(464(1A1($$(lt6(4((2C+(amp+1( 803(3amp41amp4(1$4+(4(541(A$4B(amp+(+$C+(7Bamp(

E$$5(36( 803(3amp41amp4F(15amp(lt6(4(amp31amp$B($11(gt( 1$4(amp(ampltlt3amp4(03(amp(44amp(lt1(amp5(lt6(

GC$+( 8221(420(3amp(4(6691A1amp(051((4(410$(+(4( 661(1amp+541(020amp(4(=0(0amp+(3$F(

20

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Table9Reportedandcalculatedgrowthratesfromtheliterature

Calculatedgrow

thratesbasedon

informationprovidedinliterature

aApproximationsofmaximum

grow

thpotential(basedon

average13 maximum

sizesiffishreportedatharvest

21

13

General Information on Factors that Affect Fish Growth

Growth in fish is extremely variable and is impacted by many different

physiological and environmental factors Growth rates are known to change with size and

age sex season activity level density amount13 of living space quality and quantity of food

genetics and temperature (Brett 1979) Growth experiments conducted at different times

of year can result in growth rates that are not comparable As fish become larger their

physiological13 potential to grow decreases making determination of growth rate dependent

on the size of the starting fish and the length of the experiment (Busacker et al 1990)

Genetic factors also have great potential to influence growth rate Some species have

strains13 and13 races13 that display vastly different growth potentials (Reinitz et al 1979) All of

these factors combine to make assessment of the individual factors controlling fish growth

difficult13

Water temperature is probably the most important variable affecting growth rate13

All of the basic functions that affect growth such as feeding digestion and metabolism are

temperature-shy‐dependent13 Growth13 is inseparably13 tied13 to13 bioenergetics13 and13 therefore13 also13

tightly tied to temperature When temperatures are below optimum daily temperature

fluctuations can stimulate growth Photoperiod is also commonly linked to water

temperature and can influence growth rates in fish (reviewed in Brett 1979)

Fish density13 is known to13 affect growth13 and13 can alter13 growth13 rates13 in several ways13

Fish that exhibit strong territorial behaviors13 or natural schooling tendencies13 will

experience reduced growth if densities are too high or too low (Brett 1979) Dominance

hierarchies where some fish feed more aggressively than others can also lead to high

variability13 in growth13 rates13 (Koebele13 1985) Crowded13 conditions13 also13 cause physical

interference13 between13 fish and13 poor water13 quality13 which13 reduces13 growth13 (Busacker13 et al13

1990) The effects of fish numbers space and feeding opportunity are frequently correlated13

and often13 difficult13 to distinguish (Brett13 1979)13

It is impossible to study the effects of environmental factors on growth without also

evaluating feed rations (Brett 1979) Amount of food quality of the diet particle size

number of feedings per day and time of feeding have all been shown to affect growth

(Busacker et al 1990) In controlled laboratory studies food is usually fed ad libitum13

22

13

(constantly available) and other variables are altered to assess impacts of environmental

factors13 on growth13 These studies13 are13 usually13 conducted13 in tanks13 or raceways13 because13

researchers must verify that food is constantly available to the fish which is difficult to do

in large pond environments where the fish and the bottom13 are often not visible (Busacker13

et al13 1990)

Specific Information13 o Razorback13 Sucker13 Growth

Variable13 growth

Growth in razorback suckers is naturally highly variable and may be a function of

their evolutionary history (USFWS13 2002)13 Minckley (1983) speculated that13 wide size

variation in a single cohort of razorback suckers may be adaptive with fast-shy‐growing13 fish

that13 reproduce at a young13 age surviving13 better in13 high discharge years and slow-shy‐growing13

smaller fish surviving better during drought periods This highly variable growth rate

makes rearing razorback suckers in a production setting difficult because fish from13 a single

cohort do not reach the target stocking size simultaneously One of the major tasks for

aquaculture is to maximize both individual growth and total production13 (Gerking13 1978)13

This becomes more difficult when the species being cultured exhibits highly variable

growth13 rates13 because of genetic influences as is the case with razorback13 suckers13

Razorback13 sucker growth13 is typically very13 rapid13 during13 the first13 year of life13 and then13

declines with age First year growth can be as low as 50 mm and as high as 350 mm (Valdez

et al13 1982 Minckley13 1983 Mueller13 1995) Razorback sucker13 grow rapidly13 for

approximately the first five or six years of life and then growth slows13 (McCarthy13 and13

Minckely 198713 Tyus 199813 Minckley et13 al 1991)13 Growth of older individuals in13 extant13 wild

populations is very13 low (Minckley 198313 Tyus 198813 Modde13 et al 1996)13 Wild growth13 rates

for mature adult fish in Lake Mohave based on PIT tag recaptures were often too small to

be accurately measured for both males and females over the time period of 1987-shy‐199713

(Marsh and Pacey 1998) This information suggest it will take substantially longer to rear

fish to13 increasingly13 larger13 stocking13 sizes (40013 ndash 500 mm TL) than it did to reach the target

size of 300 mm TL

Growth in ponds

23

13

One of the main strategies for maintaining genetic refugia and self-shy‐sustaining13

populations of razorback13 sucker in the lower Colorado13 River basin13 is to rear razorback13

sucker13 larvae13 in production13 ponds until they13 are13 a suitable13 size for stocking13 (USFWS13 2004)

Pond culture has proven useful to promote rapid growth of juvenile razorback suckers

(Kaeding and Osmundson 1989) Marsh (1994) reported that growth rates of razorback

suckers13 reared13 in golf-shy‐course13 ponds exceeded13 the13 best growth13 rates13 obtained13 under

intensive13 culture13 conditions13 at federal hatcheries13 especially13 during the13 first several years13

of life Growth rates in these semi-shy‐natural ponds are also comparable to estimated growth

rates13 of juvenile13 wild13 fish (McCarthy13 and13 Minckley13 1987) Modde13 and13 Haines13 (2005)

reported13 the13 greatest growth13 rates13 in the13 largest and13 deepest floodplains13 with13 the13 greatest

amount of submergent vegetation but excellent growth and survival of fish in a grow-shy‐out

pond is of little value if there is not an efficient way to collect the fish from13 the pond

(Kaeding and Osmundson 1989)

Temperature13

Bulkley and Pimentel (1983) used shuttle boxes in the laboratory to determine a

temperature preference13 for razorback suckers13 of 23-shy‐24degC13 In13 their13 studies13 razorback

suckers were found to avoid temperatures below 118 degC or above 286 degC Razorback

suckers at Bubbling Ponds Hatchery are more active in the spring and feed better as

photoperiod increases even prior to water temperatures rising (Frank Agygos personal

communication) Table 3 briefly summarizes water temperature data from13 each facility

Detailed seasonal water temperature profiles are not currently available for many

razorback grow-shy‐out sites13

Density13

Extensive studies have been conducted on commercially important species to

evaluate stocking densities and feeding rates that maximize production For these species

controlled experiments under laboratory conditions have established relationships

between temperature density and feed ration on growth (Brett 1979) but this information

is sporadic13 or non-shy‐existent for razorback suckers13 (Bays13 et al13 2005) Fish culturists13 with13

24

13

experience13 rearing13 razorback suckers13 typically13 have13 target stocking13 densities13 that13 they use

(Tables13 4 -shy‐ 5) These stocking densities have largely been determined over time by trial

and error These approximate stocking densities provide a good starting point for more

controlled13 types13 of replicated13 pond studies13

Feed ration

Razorback13 suckers are currently13 being13 fed a wide variety13 of prepared diets (Table 7)

that range from13 a slow-shy‐sinking salmon feed manufactured by Silver Cupreg to a spirulina

and krill-shy‐enhanced catfish feed made by Rangenreg Most locations are feeding 20 ndash 50

body13 weight per13 day13 Methods13 for culture13 of razorback sucker13 larvae13 in intensive13 settings13 at

fish hatcheries are well documented (Figiel 2005) and various larval fish diets have been

evaluated13 (Tyus and13 Severson 1990 Severson et al13 1992) but no standardized13 procedures

are used for feeding13 larval13 fish in13 intensive settings13

Razorback sucker larvae are also effectively reared in pond environments using

natural foods supplemented with larval fish diets and survival is high when no predators

are present13 (Mueller 2006)13 Growth rates for larval13 and early juvenile razorback13 suckers

may increase with pond fertilization Diet and physiological studies on wild razorback

suckers indicate that they feed on plankton as well as benthic organisms during their entire

life (Marsh 1987) Artificially fertilizing ponds may greatly increase production capacity

and growth rates for razorback13 sucker (Papoulias and Minckley13 1992) and warrants

further13 investigation13

Handling stress

Handling stress13 has13 been shown to13 influence growth13 rates13 Paukert13 et al (2005)

found that growth of bonytail chub was reduced by 26when compared with controls

after being13 repeatedly13 captured and handled in13 hoop13 nets13 Handling13 effects are likely13 to be

similar for razorback suckers that are repeatedly13 captured and sorted in13 a hatchery13 setting13

Razorback suckers that are handled at Willow Beach National Fish Hatchery will commonly

not eat for two weeks after handling (John Scott personal communication) This creates a

difficult situation13 for production13 facilities because13 fish13 need to be sorted to ensure13 large13

25

13

aggressive fish do not interfere with growth of smaller individuals but frequent handling

and sorting13 causes stress related reductions in13 growth13

Measuring Growth in Captive Fish

Weight is the traditional measure used to estimate growth or production in

aquaculture settings13 Groups of fish are typically13 weighed and an average individual13 weight13

is computed (Busacker et al 1990) Although this method is often logistically the easiest it

may not be the most informative for species with highly variable growth rates like

razorback suckers especially when target lengths must be reached before fish can be

stocked Weight can also be highly influenced by things like stomach fullness or

development of gonads (Busacker et al 1990) Condition factor or relative weight can also

be used to assess growth of fish but these tools may be more robust predictors of fecundity

than of growth (Anderson and Neuman 1996) For some species sexes need to be

distinguished because males and females may differ in morphology (Anderson and

Neumann 1996) Mueller (2006) analyzed growth rates based on PIT tag recaptures of 86

razorback suckers13 in High13 Levee Pond13 and13 found13 that differences13 in growth13 do not appear13

to occur until fish are over 450 mm TL at which time growth rate in males slows while

females continue to grow at a slightly higher rate This would indicate that sex may not be

an important factor to consider when examining growth rates unless the target grow-shy‐out

size is above 450 mm TL

The best measures of growth are often determined from13 the length and weight of

individuals rather than from13 groups of fish (Anderson and Nuemannn 1996) because

individual growth rates give better estimates of confidence and variance (Busacker et13 al

1990) Length frequency analysis or recapture of previously marked individuals of a known

size is likely to yield the most useful information for razorback sucker growth The success

of any of these methods depends on proper sampling procedures that are representative of

the population as a whole (Busacker et al 1990) Sampling methods that are known to be

size-shy‐biased such as trammel nets (Mueller et al 2004) or cast nets should not be used when

trying to measure growth rates13

26

13

Conclusions

For razorback sucker survival is largely associated with stocking size Additional

focused13 research13 is therefore13 needed to13 identify13 ways13 to13 increase13 growth13 rates13 of captive-shy‐

reared13 razorback sucker Growth13 rate13 in fish is controlled13 by many factors including fish

size and age temperature density and feed ration which can all be highly correlated

Growth of razorback suckers is also inherently variable which makes the task of identifying

the key factors that13 affect13 growth in13 captivity even more difficult The focus at most

razorback rearing facilities13 is production so the13 types13 of data that are13 collected13 are13 often

insufficient for detailed13 evaluations13 of individual rearing13 practices13 on growth13 Surveys of

existing13 razorback sucker13 rearing facilities indicate that culture methods vary widely and

the types of growth data13 that13 are collected are not13 standardized13 Replicated studies with

detailed information on rearing location water temperature initial stocking size stocking

density and the sizes of all fish at harvest are needed in order to compare the effects of

individual rearing practices on growth This type of research will ultimately provide both

time and cost-shy‐savings to production facilities by reducing the amount of time necessary13 for

razorback sucker to reach stocking size improving overall production efficiency

Optimum13 rearing densities for razorback sucker larvae and juveniles remain to be

determined Current stocking densities will be very useful as starting point for more

detailed studies and although optimum13 rearing densities are likely to be site-shy‐specific13

replicated studies on density will provide a valuable reference for hatchery managers

Frequency13 of sorting is another13 area that needs13 further13 research Frequent

handling13 and13 sorting13 can13 cause13 stress-shy‐related13 reductions13 in growth but not sorting can

create dominance hierarchies that further reduce growth rates of subordinate individuals

The effects13 of sorting13 on overall fish growth13 in both13 pond and13 intensive13 culture13

environments warrant further investigation Research techniques for these types of

experiments are well understood and typically utilize a matrix of replicate ponds per

variable (Bays et al 2005) In every case accurate and complete records of sampling

procedures and data collection are needed in order to interpret data and make inferences

about13 growth rates (Busacker et13 al 1990)13

27

13

Additional research is also needed to evaluate long-shy‐term13 survival of stocked fish

reared in ponds compared to fish13 reared13 in intensive13 culture13 facilities13 Exercise13

conditioning13 and predator-shy‐recognition training may also increase survival of stocked fish

and be more economically feasible than rearing fish to increasingly larger sizes prior to

stocking13 The success13 of traditional fish hatchery programs is measured largely by the

number of fish stocked but hatchery programs for endangered species must measure

success in terms of long-shy‐term13 survival and species recovery (Brannon 1993 Anders 1998)

A specific list of research recommendations follows

Specific Research13 Recommendations13

bull Use replicated studies13 to establish optimum stocking13 densities13 for ponds13 and

tanks13 that can be used as13 a starting13 point for site specific refinement

bull Determine if sortinggrading13 improves13 overall growth rates13 in both ponds13 and

intensive culture facilities13

bull Investigate the use of artificial fertilizers13 to improve growth of both juvenile

and adult razorback suckers13 in ponds13

bull Determine if the razorback sucker diet gives13 better growth rates13 than cheaper

catfish or salmon feeds

bull Evaluate growth rates13 and production potential of new intensive culture

methods13 such as13 large circular tanks13

bull Evaluate13 long-shy‐term survival of fish produced from raceways13 and circular tanks13

compared to fish reared in ponds13

bull Evaluate more effective means13 of treating13 fish diseases13

bull Evaluate factors13 other than size that may increase post-shy‐stocking13 survival such

as13 exercise conditioning13 predator recognition training or rearing13 under more

natural settings13

28

13

II The Effect of Disease Treatments on Razorback Sucker

Growth

Section13 SummaryFormalin copper sulfate potassium permanganate and13 salt are all chemicals commonly13 used13 to13 treat13 Ichthyophthirius multifiliis outbreaks in captive razorback sucker (Xyrauchen13 texanus) Weexposed 190 juvenile13 razorback suckers (127 ndash 26 mm TL) to13 5 5-shy‐day treatments with13 each13 chemical to evaluate the effects13 these chemicals13 may have on growth Fish grew an average of23513 mm TL13 during the month13 study period Fish treated with formalin grew on average13 29mm TL (03 mmday) while fish treated with copper had the lowest growth averaging 20 mmTL (021 mmday) No significant differences in13 growth were observed among fish treatedwith any of the chemicals compared to untreated fish (pgt005) Reductions in growth13 as aresult of repeated chemical treatments are not likely the cause of differences in growth ratesamong13 facilities that raise razorback suckers Repeated chemical treatments may13 have otherimpacts to overall13 fitness or long-shy‐term survival but13 these effects were not13 evident13 in our study

29

13

Introduction

Preservation13 of razorback sucker13 (Xyrauchen texanus) currently13 depends on captive13

rearing and stocking programs until permanent solutions to factors that prevent wild13

recruitment are found Low survival of stocked razorback suckers (Brooks 1986 Marsh

and Brooks 198913 Marsh and Pacey13 2005) has caused target13 sizes for stocked fish to

steadily increase in efforts to reduce predation mortality (Marsh et al 2005 Schooley and

Marsh 2007) Rearing fish to larger sizes at hatcheries comes with increased costs and

creates the need to evaluate husbandry and rearing practices that may affect fish growth

Formalin copper sulfate potassium13 permanganate and salt are all chemicals

commonly used at razorback sucker rearing facilities to treat outbreaks of the protozoan

parasite13 Ichthyophthirius multifiliis ldquoIchrdquo is one of the most pathenogenic diseases of

cultured13 freshwater13 fishes (Matthews13 2005) and causes large13 losses in captive13 populations13

of endangered razorback sucker Each of these chemicals used to treat Ich only kill the free-shy‐

swimming life stage of the parasite13 requiring13 repeated doses over several13 days depending13

on water temperature These chemicals treatments are needed to prevent loss as a result

of disease outbreaks but the cumulative effects repeated disease treatments have on

growth13 are13 unknown

Copper13 sulfate13 has13 been shown to13 significantly13 reduce13 growth13 of channel catfish13 in

production13 ponds (Rabago-shy‐Castro13 2006) but it is unknown whether13 razorback suckers13

experience similar reduced growth following copper treatment Quantifying the impacts of

disease treatments on growth will help to interpret the wide differences in growth rates

observed13 at various13 razorback sucker13 production13 facilities13 throughout the13 southwest

(Ward et al 2007) If one chemical is found to have less detrimental impacts on growth

than another then it may be preferred for use as a disease treatment We evaluated growth

rates13 of razorback suckers13 under13 replicated13 and13 controlled13 conditions13 to13 assess13 effects13 of

repeated formalin copper sulfate and potassium permanganate and salt treatments on

growth13

Methods

We captured 190 juvenile razorback suckers from13 ponds at Bubbling Ponds Fish

Hatchery AZ using hoop nets or cast nets All fish were of the same age class and

30

13

averaged 179 mm total length (TL) (range13 = 127 ndash 262 mm TL)13 These fish were13 offspring13

of captive13 razorback sucker13 broodstock held13 at Dexter13 National13 Fish Hatchery13 NM13 (2007

year class) All fish were tagged with passive integrated transponder (PIT) tags and

quarantined for one month prior to the experiment to allow fish to recover from13 tagging

and become accustomed to being held in circular tanks

At the beginning of the study all fish were weighed measured and scanned for

individual tag numbers with 19 randomly selected fish placed into each13 of 10 8-shy‐foot

diameter circular tanks (Figure 2)13 Each13 tank contained13 two13 airstones13 and13 an13 individual

biofilter with a recirculating water pump (31 litersminute) that had been operating for

at least 1 month prior to the experiment to allow bacterial colonies to become

established Two tanks were designated as a control and did not receive any chemical

treatments while the other eight tanks received formalin copper sulfate potassium13

permanganate or salt treatments at two week intervals (two tanks per chemical

treatment) Formalin copper sulfate and potassium13 permanganate were treated at 1 part

per million (ppm) and salt was applied at 30 parts per thousand (ppt) These treatment

rates are commonly used to treat13 razorback13 suckers for ich at Bubbling13 Ponds Fish13

hatchery (Frank Agygos personal communication)

Figure 213 Photo ofexperimental tankswith individualbiofilters and aeration

31

13

Each treatment consisted of a series of doses applied on Wednesday Thursday and

Friday with a 90water change between each dose Biofilters were removed from13 all

tanks and held in a separate holding facility during treatments and then replaced on the

Monday following treatments after a 90water change This schedule allowed fish to be

exposed to chemical treatments for 5 consecutive days without water quality deteriorating

This 5-shy‐day chemical treatment was repeated every two weeks from13 July to October (97

days)13 for a total of 5 5-shy‐day treatments Water temperature in the treatment tanks ranged

from13 13degC (55degF) to 32degC (91degF)

Fish were fed a fixed ration of commercial razorback diet (Silvercup 4mm13 pellet)

once daily13 (2 percent body13 weight per day13 as calculated13 by13 average initial fish weight)13

At the end of the experiment all fish were again weighed measured and scanned for

individual tag numbers Growth of fish in each treatment group was compared using

analysis of variance (ANOVA) Any mortalities13 that occurred during the13 study13 were13

replaced with previously quarantined fish of equivalent size to maintain equal densities in

each13 tank13 but growth13 data was13 only13 recorded for fish which13 survived13 the13 entire13

experiment

Results

Fish at the13 start of the experiment averaged 179 mm TL (Range13 = 127 ndash 262 mm)

with no significant differences in fish length among treatment groups (F(4189) = 00183 p

gt 0999 ANOVA) On average fish grew 235 mm TL (024 mmday) during the 3 month

study13 Fish in tanks13 treated with formalin had the highest growth averaging 29 mm TL (03

mmday) while fish in tanks treated with copper had the lowest growth averaging 20 mm

TL (021 mmday) Fish in the control tanks averaged 213 mm TL in growth (022

mmday) (Figure13 3)13 Formalin-shy‐treated fish grew13 significantly faster than13 any other

treatment group but no13 significant differences in growth13 in length13 or weight were13

observed among fish treated with any of the chemicals compared to untreated (control)

fish (pgt005 ANOVA)

32

13

Figure 313 Average growthof razorback suckersexposed to a series of 5 5-shy‐day chemical treatmentsover a 97-shy‐day13 periodError bars representstandard error

Discussion13

Growth13 rates13 observed13 in our study13 (021 ndash 03 mmday) are low compared to those

reported13 in other13 studies13 of razorback sucker13 growth13 (0213 ndash 18 mmday) (Ward et al

2007) Using recirculating water systems for our study required filters to be removed and

replaced during treatments Stress to fish caused by removing and replacing filters within

the tanks as well as repeated water changes may have led to overall higher stress and

reduced growth rates compared to those reported for unconfined fish Growth in fish is

highly variable and is affected by many different physiological and environmental factors

including fish size density temperature amount of space and food (Brett 1979) We

strived to control each of these factors but other factors may have also influenced growth

in our experimental tanks During mid-shy‐summer water temperatures in the treatment

tanks reached 32degC (91degF) At these warm13 temperatures fish are very susceptible to

bacterial13 infections13 The slightly higher growth exhibited by fish in the formalin and

potassium13 permanganate treatments may have been the result of these two chemicals

33

13

being effective at controlling bacterial infections The differences in growth we measured

among treatment groups were not statistically significant and do not appear13 biologically13

meaningful during the relatively short duration of this study (97 days) although the

cumulative effects of slightly reduced growth could be biologically meaningful over longer

time frames

Reductions in growth13 as a result13 o repeated chemical treatments are not likely the

cause of differences in growth rates among facilities that raise razorback suckers

Repeated chemical treatments may have other impacts to overall fitness or long-shy‐term13

survival but these13 effects13 were13 not evident in our study It is more likely that the parasite

outbreaks themselves are the cause of different growth rates among razorback rearing

facilities rather than the chemical treatments used to treat the parasites We recommend

that hatchery managers continue to use the chemicals that are most effective at controlling

ldquoIchrdquo13 at their individual13 facilities

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower Colorado Rive Multi-shy‐species13

Conservation Plan under Work Task C10 We thank Ty Wolters and Tom13 Burke for their

support of this research and Frank Agygos and Dave Billingsly of the Bubbling Ponds Fish

Hatchery13 for their13 technical assistance13 and13 help with13 collecting13 fish

34

13

III13 Razorback Growth Rates at Bubbling Ponds ndash 2009-shy‐2011

Section13 SummaryExperimental studies at Bubbling Ponds Fish Hatchery AZ have strived to understand

factors that affect razorback sucker growth in captivity and identify ways to improve growthrates and maximize size at release Rather than performing experimental studies that wouldrequire major13 rearrangement (and likely reduced production)13 of hatchery operations our13 studies13 used normal variation in production techniques13 and practices13 to isolate factors13 thatmay modify growth rates

Our initial work identified razorback13 growth rates in13 lined ponds at standard fishdensity as 026 to13 028mmday (789 to 843 mmmonth) No significant differences in growthrate were observed among fish that had been in the pond only during the winter13 periodcompared to fish that had been in the pond the entire year indicating that water temperatures13 at Bubbling Ponds are high enough to allow fish to incorporate feed effectively year-shy‐roundHowever these growth rates are lower than most values reported from the literature fromnatural or semi-shy‐natural pond environments No significant differences in13 growth rate wereobserved13 between large and13 small fish13 within the 150 ndash 29 mm TL13 size range Additional worksuggests13 that razorback suckers13 tagged at over 300 mm TL had reduced growth rates (024mmday 73 mmmonth) as would be expected according to a typical Von13 Bertalanfy growthcurve although growth rates13 were only slightly less13 than the average growth rate for thehatchery (027513 mmday 82513 mmmonth)

Sorting13 to13 separate small fish from large fish after the first year of growth is practicedesigned13 to allow smaller fish to ldquocatch uprdquo to larger fish We found that13 this technique doesappear to13 improve growth rates of smaller fish Growth rates of sorted small razorback suckers(029 mmday 87mmmonth)13 were equal to that13 of larger13 fish (028 mmday 8413 mmmonth)indicating that sorting may have helped to offset their original slower growth trajectory

Bubbling Ponds Fish Hatchery grows razorbacks in 6 long deep ponds lined with heavyplastic 2 long deep13 earthen13 (unlined) ponds and three wide shallow earthen ponds The wideshallow ponds13 have historically produced very large fish at low density but have been found tomaintain much lower fish numbers than deeper ponds We found13 that growth13 rates ofrazorbacks kept at high density (4-shy‐700013 fish)13 in a wide shallow pond grew extremely slowly(024 mmday 726 mmmonth) This growth rate is among the slowest of any fish over theyears of our study and demonstrates that13 though the large ponds may produce large fish at lowdensity13 they are unable to overcome high13 fish13 densities

Finally one of the major factors influencing13 fish13 growth13 in hatcheries is disease onemajor summer-shy‐time disease at13 Bubbling Ponds is the ectoparasite Ich (Ichthiopthirusmultifiliis) To investigate the impact Ich has on razorback growth we eradicated fish from thespring and water conveyance ditch that supplies13 water to the hatchery using Rotenone This13 restoration effort was fairly short-shy‐lived (Ich returned to the hatchery within four months) but

35

13

growth13 rates of fish13 reared for four months without Ich present (031 mmday 92 mmmonth)were significantly higher than the following 8 months of growth for those same fish (022mmday 65 mmmonth) This disease-shy‐free growth rate is in fact faster than any13 otherprevious growth rates observed at the hatchery in our study

We conclude that growth rates at the Bubbling Ponds Fish Hatchery are likely as highas possible given the pond densities required to13 meet production goals and the Ich-shy‐infestedwater13 that feeds the facility Sorting practices are successful in helping as many fish as possiblereach stocking length as fast as possible Unlined ponds may be able to grow large fish at lowdensities but whatever factors allow for that growth13 are not able13 to overcome13 high fish densityThus the large lower ponds at Bubbling Ponds may be better utilized via renovation to13 deepenand line them

Disease is the most important factor limiting growth as may be expected to be the caseat many13 hatcheries While the spring renovation was not13 a complete success13 the dramaticreduction of fish populations in that habitat was enough to dramatically13 reduce13 the13 occurrenceof Ich at the hatchery13 Such open spring13 systems feeding a hatchery are a misfortune that canbe expected to transmit disease so we suggest that renovating the spring again to combat13 IchImproved techniques to divert water from13 the springs and more throuough treatment ofstream-shy‐side vegetation may improve the success of chemical treatment Successful renovationwould likely both improve growth rates and reduce chemical costs associated with treating Ichoutbreaks Even13 if complete renovation13 is impossible or impractical an13 effort to reduceinvasive fish density in the springs13 which act a vector for the parasite(and thereby reduce thelikelihood of13 Ich being transmitted into ponds) may still13 show dramatic improvements

36

13

Introduction

Conservation efforts13 for razorback sucker13 (Xyrauchen texanus)13 currently13 depend on

captive rearing and stocking programs Low survival of stocked razorback suckers (Brooks

1986 Marsh13 and13 Brooks13 1989 Marsh13 and13 Pacey13 2005) has13 caused13 target sizes for stocked13

fish to steadily increase in efforts to reduce predation mortality13 (Marsh13 et al13 2005

Schooley and Marsh 2007) Rearing fish to larger sizes at hatcheries comes with increased

costs and creates the need to evaluate husbandry and rearing practices that may affect fish

growth13 We evaluated growth13 rates13 of individual razorback suckers13 in ponds13 at Bubbling

Ponds Fish Hatchery13 using Passive Integrated13 Transponder (PIT) tags13 to13 obtain13 precise

growth information for individual fish so that valid comparisons of growth rates as related

to rearing practices can be made

Due to the critical nature of the razorback sucker stocking program we did not

design experimental studies that would require major rearrangement and potentially

reduce production of hatchery operations Instead our studies used normal variation in

production techniques and practices to isolate factors that may modify growth rates

Though this methodology dramatically limits replication and may limit our ability to

directly13 attribute13 differences in growth13 rates13 to13 the13 variables13 we13 investigate13 we13 were13 able13

to accomplish research goals without altering hatchery operations or impacting

production

From13 2009 through 2011 we conducted a series of observational13 growth13 studies to

determine growth rates of individual razorbacks at Bubbling Ponds The first set of

experiments included13 identifying13 growth13 rates13 in lined13 and13 unlined13 ponds determining

growth13 rates13 of fish at different13 sizes13 in13 relation13 to sorting13 practices and monitoring

razorback growth rates after removing the source of the ectoparasite13 Ich (Ichthiopthirus

multifiliis) from13 the hatchery water source13

Razorback growth rate in lined ponds

Our first growth study documented individual growth rates at normal density in 11

million gallon lined ponds13 over two13 years13 This is the standard13 grow-shy‐out process for

razorbacks13 at Bubbling Ponds We monitored growth of fish for a variety13 of sizes and13 the13

37

13

amount of time in a pond during the growing season These13 data give a snapshot of growth13

rates13 at the13 facility13 and13 provide13 the basis for comparisons throughout our study

Growth rate13 in an unlined pond

In addition13 to 6 ponds lined with heavy plastic13 sheeting13 Bubbling Ponds Fish13

Hatchery maintains two narrow and deep (same dimensions as lined ponds13 Figure13 4)13 and13

three large13 shallow unlined ponds These earthen13 ponds typically have vegetation and

associated aquatic invertebrates that may better simulate natural environments by

providing cover and improved food diversity or quality Therefore these unlined ponds

may be expected to produce higher growth rates and potentially improved survival that is

more similar to growth rates observed in more natural grow-shy‐out facilities13 Historically13 the13

large13 shallow13 ponds have produced very large fish when13 utilized at low13 fish density13 The

narrow13 deep earthen13 ponds are13 used to grow13 fry13 at high density in their first13 year of life

The major downside to unlined ponds is the difficulty in harvesting fish where a lined

pond might take 8-shy‐1013 people13 a half13 day13 to13 harvest13 lined13 ponds13 require13 intensive13 weeding13

to allow seines to be pulled and therefore require many more personnel-shy‐hours13 In addition13

to harvest challenges the shallow earthen ponds tend to suffer from13 dissolved oxygen

crashes during the summer Unlined ponds also may maintain higher13 populations13 of non-shy‐

target species such as bluegill sunfish mosquito fish and bullfrog tadpoles We measured

growth rates of suckers in a large shallow earthen pond for comparison to growth in lined

ponds13

Figure13 4 Lined13 and13 earthen ponds13 of similar dimensions (approx 1000000 gallons first

and second panels) and a large13 shallow13 earthen13 pond (third panel)

38

13

Effect of sorting on growth

Razorback13 suckers13 are13 currently13 sorted13 after their first13 year of growth13 They are13

typically removed from13 one of the13 upper earthen13 ponds and13 split into13 two13 lined13 ponds for

subsequent grow-shy‐out13 The larger13 fish (gt approximately 140 mm) are placed into one pond

and the smaller individuals in another It is possible that the larger fish were more

aggressive or adept13 at taking food so this sorting process is intended to allow smaller fish

to improve their growth rate

Effect of Ich on razorback sucker growth rates

We13 evaluated13 growth13 rates13 of razorback sucker13 in the13 presence13 and absence of the

ectoparasite13 Ich (Ichthiopthirus multifiliis) Ich outbreaks can occur in wild populations13 but

hatcheries13 have13 proven excellent locations13 for Ich because13 of very high fish densities13 which13

facilitate13 the13 transfer13 of Ich13 between13 fish This common fish parasite causes direct mortality13

to razorback13 suckers as well13 as secondary bacterial13 infections13

The open spring and13 ditch13 which13 provides water to the Bubbling13 Ponds Hatchery

has long13 been infested with mosquitofish (Gambusia affinis) that harbor13 the13 Ich parasite13

and allow13 it13 to enter the hatchery with incoming13 water13 The solution13 to13 the13 Ich problem13

was to remove the mosquitofish host using13 Rotenone Razorback13 sucker growth13 rates were13

then tracked in13 the absence of this parasite for 4 months and compared with growth rates

after Ich returned to the pond and from13 previous years

Methods

Razorback growth rate in lined ponds

On May 14 2008 141 razorback suckers were tagged with 12 mm PIT tags (1342

kHz) and placed in Pond 3 (approximately 1100000 gallons13 Figure13 4)13 at Bubbling13 Ponds

Fish Hatchery Fifty-shy‐three of these tags were recovered two months later when a large

Ichthyophthirius multifilis (Ich) outbreak killed many fish in the pond On October 15 2008

an additional13 145 PIT tagged13 fish were13 also placed into Pond13 3 On13 May13 14 2009 Pond13 3

was harvested and a total13 of 141 PIT tagged fish were recovered13 Of the tagged fish13 26 fish

had13 been13 in the13 pond since May13 of 2008 (378 days13 o growth) and 115 had been13 in13 the

39

13 40

pond since October13 15 2008 (211 days13 of growth) Numbers of fish in Pond 3 after the Ich

outbreak and for the majority of the period of growth were between 3 000 and 4000 fish

A Hobotempreg temperature13 logger13 was13 also13 installed13 in Pond 3 one meter below the water

surface13 near13 the13 outflow and13 recorded water temperature every 3 hours to allow analysis

of the effects of water temperature on growth rate (Figure13 5) This Hobotemp data is

representative of other pond temperatures throughout this study

In a second experiment 210 adult13 razorback suckers13 were13 PIT tagged13 on13 May 14

2009 and13 placed13 into13 Pond13 3 upper to13 evaluate13 growth13 rates13 of larger13 razorback suckers13 at

Bubbling13 Ponds Hatchery13 under current13 rearing13 conditions13 Size of these fish at tagging13

was (mean = 285 mm range = 205 ndash 396 mm) These fish remained in the pond for 257

days and were harvested on Jan 25 2010 to provide information on growth rates of larger

razorback suckers13 under13 current rearing conditions

Figure 513 Temperatures (degC) inrearing pond at BubblingPonds Hatchery from July toSept 2009 (top graph)13 andfrom Nov to Dec 2009 (Lowergraph) Temperaturesrecorded with a Hobotempregremote data logger13 every 3hours

13

Growth rate13 in an unlined pond

To document razorback sucker growth in earthen ponds we introduced13 225 tagged13

razorback suckers13 into13 Pond13 1 lower13 (Figure 4) in February 3 2010 Additional tagged fish

from13 other studies were added to the pond throughout the growing season and the density

of 1 lower reached a maximum13 of nearly 7000 fish in early summer 2010 Density was

reduced to approximately 6000 fish by capturing fish with hoop nets on June 3 2010 54 of

these fish were tagged fish and returned to 1 lower after being weighed and measured The

pond was harvested on January13 2713 2011 and a total13 of 254 tagged fish out13 of 4296 fish

total were removed from13 the pond The pond was harvested on January 27 2011 (358 days13

of growth) and the tagged fish were weighed and measured Total number of razorbacks in

the pond at harvest13 was 4296

Effect of sorting practices on growth rates

On March 1113 200913 Pond13 5 upper was13 harvested13 and13 split into13 two13 separate13 groups

Two hundred of the smaller fish (average size = 122 mm TL) were PIT tagged and placed

into13 Pond13 7 upper and13 200 of the13 larger13 fish (average = 160 mm TL) were PIT tagged and

placed int Pond13 8 upper Density13 in Pond13 7 was13 4500 fish and13 in Pond13 8 there13 were13 6500

fish These ponds were then harvested after 1 year and growth rates were compared to

give information on the effects of current sorting practices Hobotempreg temperature

loggers were installed in13 Ponds 7 and13 8 during13 the13 grow-shy‐out period with13 water13

temperature recorded every 2 hours13 (Figure13 6)

Effect of Ich on razorback sucker growth rates

Bubbling Ponds spring was treated with Rotenone (CFT Legumine 5) at a

concentration of 2 ppm13 to remove all mosquitofish from13 the spring The treatment

consisted of two treatments 6 hours in duration on two consecutive days (April 12 -shy‐ 13)

using13 drip13 stations13 and13 backpack sprayers13 followed13 by13 an13 additional 6 hours13 of

detoxification using sodium13 permanganate Although 12 mosquitofish were captured in the

spring pond the week following the treatments subsequent minnow trapping (20 traps

checked13 daily13 for 3 weeks) did not capture any additional fish until August 11 2010 when

41

13

juvenile mosquitofish were again detected in the spring pond Minnow traps have

subsequently been set daily with several hundred individuals removed To evaluate if Ich

was also again present in the spring we captured 15 mosquitofish from13 the spring pond on

three separate days and placed them13 in an aquaria at 25 degC with 5 longfin dace known to be

free of Ich These fish were monitored for 2 weeks with no signs of Ich developing This

indicates that even though mosquitofish have returned to the spring pond the parasite is no

longer present13 although how13 long13 this condition13 will13 persist13 is unknown13

On May 1113 201013 200 juvenile razorback13 suckers were harvested out13 of Pond 5

upper (2009 year Class from13 Dexter National Fish Hatchery) and were PIT tagged and

placed into Pond 8 to evaluate if growth rates at bubbling ponds hatchery have improved

following the renovation of the spring and the removal of the Ich parasite Unfortunately13

on Sept13 8 2010 Ich was13 again13 detected13 in Pond 8 and the pond was immediately seined

and 74 tagged fish were measured to obtain growth information for the 4-shy‐month period

during13 which13 the13 pond13 was13 Ich-shy‐free13

Figure13 6 Temperatures (degC) in rearingponds 7 and 8 at Bubbling Ponds Hatchery13 from March 2009 ndash March 201013 pond 7(top13 graph)13 and13 pond 8 (Lower13 graph)13 Temperatures recorded with a Hobotempregremote data logger every 3 hours

42

13

Results

Growth in Lined Ponds

Razorback suckers13 that had been13 in13 Pond 8 upper for the13 entire13 year13 grew an13

average of 0263 mmday (789 mmmonth) and razorback suckers that had been in the

pond for 7 months (Oct -shy‐ May) grew13 on13 average of 028 mmday (843 mmmonth) (Figure13

7) These growth13 rates13 did not significantly13 differ Fish density13 in Pond 3 during13 the13

majority of the growth period was13 00032 ndash 00036 fishgallon13 Additionally no13 significant

differences in growth rate were observed between fish smaller than 210 mm TL and fish

larger than 210 mm TL when all recaptured fish were combined

We also measured the growth rate of very large fish in a lined pond On Jan13 2513 201013

156 adult fish with PIT tags were recovered from13 Pond 3 upper13 These fish were13 in the13

pond for 257 days and experienced an average13 growth13 rate13 of 024mmday or 73

mmmonth (Figure13 7)13 This growth13 rate13 is slightly13 lower13 than13 the13 average13 growth13 rate13

observed13 at Bubbling13 Ponds Hatchery in other studies (0275 mmday 825 mmmonth)

but may not be biologically meaningful We would expect larger13 fish to13 have13 reduced

growth rates according to a typical Von Bertalanfy growth model (Bertalanffy 1957) but it

appears that13 over the size range we evaluated (300 -shy‐ 450 mm TL) growth rates have not

slowed significantly compared to that of smaller13 fish grown at Bubbling Ponds13 Hatchery

Growth13 of razorback suckers13 is known13 to13 slow as13 fish reach13 larger13 sizes but it appears13 this13

reduced growth rate may not really start to be biologically meaningful at Bubbling Ponds

Hatchery13 until razorback suckers13 exceed 450 mm TL

Growth in unlined ponds

Growth13 rates13 for the13 fish recaptured13 during13 the Pond 1 lower13 thinning13 (120 days13 in

the pond) was 024 plusmn 003 mmday (729 plusmn 090 mmmonth) (Figure13 8)13 Fish13 that were13 in

the pond for nearly the entire year grew13 an13 average13 of 024 plusmn 001 mmday (726 plusmn 027

mmmonth) These growth rates are surprisingly the lowest measured growth rates for

any part of our study and differ significantly from13 every other measured growth rate

except very large13 fish (Figure13 9)13 Separating13 out13 large fish that13 were in13 the pond for the

entire year makes no difference fish that were added to the pond at TL lt300 mm grew

43

13

Gro

wth

Rat

e (m

md

ay)

020

026

032

0244 plusmn 001 mmday (733 plusmn 028 mmmonth) and and those with TL gt= 300 mm at the

start of the experiment grew 022 plusmn 003 mmday (651 plusmn 101 mmmonth)

Razorback Growth Rates in Lined Ponds

Figure 7 Growth ofrazorback suckers in(mmday plusmn standard error)in Pond 8 upper in 2008-shy‐2009 An ANOVA did notdetect any significantdifferences

7 Months Full Year 300+ mm fish

Effects of sorting on growth

One hundred and seventy five tagged razorback suckers were recovered from13 Pond

8 upper13 on March13 24 2010 (378 days13 of growth)13 These were13 the13 larger sorted13 fish (gt140

mm TL) that came out of Pond13 5 on March13 11 2009 One13 hundred and13 twenty13 two13 tagged13

razorback suckers were also recovered from13 Pond13 7 upper on March13 31 2010 (385 days13 of

growth)13 These were13 the13 smaller sorted13 fish (lt140 mm TL) that came out of Pond13 5 on

March 1113 200913 No significant differences in growth rate (mmday) were observed among

larger fish in Pond 8 and smaller fish in Pond 7 (pgt005 ANOVA) (Figure 10)13 indicating

that13 sorting may have helped to offset the original slower growth trajectory of the smaller

fish Temperatures of Ponds 7 and 8 upper remained similar throughout the year13 (Figure

5)

44

13

13

13

Gro

wth

Rat

e (m

md

ay)

Gro

wth

Rat

e (m

md

ay)

020

026

032

020

026

032

Razorback Growth in an Unlined Pond

Figure 8 Growth of razorbacksuckers (mmday plusmn standard error) in Pond 1 lower (an unlined pond)in 2010-shy‐2011 An ANOVA did notdetect any significant differences

6 Months 12 Months lt 300 mm Fish 300+ mm Fish Growth Growth

Lined vs Earthen Ponds 1 year of growth

Figure 9 Growth of razorbacksuckers (mmday plusmn standard error) in lined and unlined ponds A t-shy‐test13 did not detect a significantdifference

Lined Pond Unlined Pond 1 Yr Growth 1 Yr Growth

45

13

Effect of Sorting G

row

th R

ate

(mm

day

) G

row

th R

ate

(mm

day

)

032

020

026

032

020

026

Smaller Fish Larger Fish

Effect of Ich

Figure 10 Average growthof razorback suckers(mmday plusmn standard error)that were size-shy‐sorted intosmall fish (pond 7) and largefish (pond 8) populations At-shy‐test did not detect asignificant difference

Figure 11 Average growth ofrazorback suckers (mmday plusmnstandard error) after Ich wasremovd from the hatcheryrsquos springand after Ich was again detected inthe pond The growth rate withoutIch is significantly higher than boththe rate after Ich and the ourstudyrsquos average annual growth ratein lined ponds (ANOVA p =00003)

Growth without Ich Growth With Ich Average Annual 4 months 4 months Growth Rate

46

13

Effect of Ich on razorback sucker growth rates

Seventy-shy‐four13 tagged13 razorback suckers13 were13 recovered from13 Pond 8 on September

15 2010 These fish had13 been13 in the pond for 4 months and experienced a growth rate of

032 mmday or 97 mmmonth (Figure13 11)13 This growth13 rate13 is significantly higher (p =

005 two sample t-shy‐test) than the mean growth rate for the same group13 of tagged fish after

Ich detection (022 mmday or 65 mmmonth) and significantly higher than any other

individual growth13 rates13 observed13 to13 date13 at Bubbling13 Ponds Hatchery13 (Figure13 11)13 If this13

growth13 rate13 were13 extended throughout13 the entire13 year13 fish on average from13 Ich-shy‐free13 ponds13

would be 16 mm longer than fish from13 ponds infested with Ich Studies conducted at

Bubbling Ponds hatchery in 2008 (Ward 2008) did not reveal any effects of the treatment

chemicals on razorback sucker growth rates so it13 is likely that13 the parasite outbreaks

themselves are causing reducing growth rates rather than the chemicals used to treat the

parasites13

Conclusions

Our results suggest that under typical hatchery operations (maximizing number of

fish produced)13 the growth13 rate13 of razorback13 suckers13 is relatively13 consistent at Bubbling13

Ponds hatchery13 at 02-shy‐03 mmday (6-shy‐9 mmmonth)13 but is lower than growth13 rates13 at

other13 facilities (02 ndash 18 mmday Ward et al 2007)13 This growth13 rate13 has13 been13 constant in

both lined and unlined ponds and at all fish densities we were able to measure To achieve13

growth13 rates13 substantially higher than this will likely require13 significant changes in rearing

practices that may not be practical in order to reach numerical production13 goals

Temperature is a key variable in fish growth but seasonal growth patterns

described13 above13 (Figure13 5) demonstrate that water temperatures are high enough in

winter to maintain razorback growth Differences in water temperature by season

currently13 do not fluctuate more than 10degC at Bubbling Ponds because of the continuous

supply of water flowing through each pond (approx 225 gallonsmin) These high water

flows appear to keep pond temperatures within the thermal preference13 for razorback

suckers13 (1213 -shy‐ 28 degC Bulkley and Pimentel 1983) throughout the entire year with

temperatures rarely dropping13 below 16deg13 C (Figures 513 6)13

47

13

Fish density is another key variable in fish growth and though the number of fish in

a pond during our study ranged from13 3000 to 700013 fish we13 did not find any13 correlation13

between13 density and growth rate13 This might yield two conclusions First13 razorback

growth13 may be changed equally13 by13 densities13 at the13 hatchery13 (ie13 a density13 of 3000 fish in a

pond is as stressful13 for razorbacks as a density13 of 7000 fish) An alternative is that other

factors13 such as disease outbreaks have13 stronger13 control over fish growth13 than13 density13

Fish density13 would13 have13 to13 be13 experimentally manipulated to test13 this13 and hatchery

operations (producing the maximum13 number of fish) prevented our manipulating density13

in ponds for this13 work The trouble with manipulating density demonstrates the difficulties

associated with changing13 hatchery13 practices experimenting with density would have

prevented BPH from13 meeting13 production13 goals Given that the stocking of smaller

razorbacks has met with very little success perhaps BPH goals could be changed from13

producing 12000 fish at 300+ mm per year to a smaller number of very large fish each

year Growing13 fewer13 larger13 fish could potentially be accomplished in the same time frame

as more smaller fish but a better understanding of how density alters growth rate would

be required to be confident13 of this

The very slow growth13 in the13 earthen13 unlined13 Pond 1 lower13 was very surprising We13

had13 anticipated13 that the13 diversified diet13 cover and13 other13 habitat features13 provided by13

unlined ponds would yield dramatically increased growth rates However these traits were

not enough to offset high fish densities and in fact the unlined pond in our study13 suffered

mortality to bring densities down to that observed normally in lined ponds

Our data13 suggest13 that razorbacks13 sucker13 growth13 rates13 are13 higher in lined13 ponds13

However we13 think the reasons13 for the13 very slow growth we observed13 in the13 unlined13 pond13

in our study13 is instead13 linked13 to13 the13 usage13 of Pond 1 lower13 during13 the13 study13 rather13 than13

intrinsic13 slow growth13 in earthen13 ponds First the pond was at extremely high density for at

least part of the study The volume of Pond 1 lower has not been estimated but hatchery

managers suggest 1500-shy‐2000 fish is an appropriate number of individuals so this pond

was at a very high density for much of the experiment Second dissolved oxygen is often

very low in the13 large13 earthen13 ponds during the heat of summer much lower than that of

lined ponds This will both limit the number of fish that can survive in the pond and almost

certainly13 increases stress13 of these13 fish potentially13 reducing growth13 The DO crashes also13

48

13

limit the amount of feed hatchery managers can give fish in these ponds sometimes for

days or weeks at a time which further reduces growth during warm13 weather

Our data13 suggests that13 growth rates at the Bubbling13 Ponds Fish Hatchery are likely

as high as possible given13 the pond densities required to meet production goals and the Ich-shy‐

infested water that feeds the facility Sorting practices are successful in helping as many

fish as possible reach stocking length as fast as possible Unlined ponds may be able to

grow13 large13 fish at low13 densities13 but whatever factors allow13 for that13 growth are not13 able to

overcome high fish density The removal of invasive13 fis that act as13 a host for the13 parasite13

Ich fish from13 the Bubbling13 Ponds spring13 allowed the highest13 growth rate at 032 mmday13

(96 mmmonth) but that growth rate decreased again as Ich re-shy‐infested13 the13 hatchery13

Consistently13 achieving13 growth13 rates13 as high or substantially13 higher than13 this13 will likely13

require13 significant changes in rearing practices that may not be practical in order to13 reach13

numerical production13 goals

Two major changes that might result in higher growth rates are substantially

reducing fish density and modifying the way spring water is delivered to the facility (via

either repeated chemical treatments or enclosed concrete water diversions) to eliminate

Ich from13 the hatchery source water Other potential changes not address by our work

include13 flow-shy‐training razorbacks much previous literature including MSCP-shy‐funded13 work

on razorback suckers13 suggests13 that fish growing13 in flowing water will grow13 faster than fish

in still water (Jorgensen and Jobling 1994) Furthermore there are a wide variety of

potential benefits associated with growing13 fish13 in flowing13 water in addition13 to increased

growth13 rates13 (Davidson13 199713 Castro13 et al13 2011) Another option13 for increasing13 growth13

rates13 include13 changing to13 intensive13 culture13 in large circular13 tanks

Finally given that the stocking of smaller razorbacks has met with very little

success13 perhaps13 BPH13 goals13 could13 be13 changed from13 producing 12000 fish at 300+ mm per

year to a smaller number of very large fish each year Growing fewer larger fish could

potentially be accomplished in the same time frame as more smaller fish but a better

understanding13 of how density13 alters growth13 rate13 would13 be13 required to13 be13 confident of this

49

13

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower13 Colorado13 River Multi-shy‐Species13

Conservation Program13 (LCRMSCP) under Work Task C10 We13 thank Ty Wolters13 Tom13

Burke13 and Eric13 Volkman for their support of this research and Frank Agygos and Dave

Billingsly13 of the Bubbling13 Ponds Fish Hatchery13 for their willingness to participate in13 this

research13 and13 for their technical assistance We also thank the LCRMSCP fish group from13

Boulder City13 NV for their assistance with harvesting13 ponds and tagging13 fish13

50

13

Literature13 CitedAnders P J 1998 Conservation aquaculture and endangered species can objective science13

prevail13 over risk13 anxiety Fisheries 23(11) 28-shy‐31

Anderson R O and R M Nuemann 1996 Length weight and associated structural indicesPages 447 ndash 482 in B R Murphy13 and D13 W Willis13 editors13 Fisheries techniques13 2ndedtion American Fisheries13 Society13 Bethesda13 Maryland

Bain M B J T Finn and H E Brooks 1988 Streamflow regulation and fish communitystructure13 Ecology13 69382-shy‐392

Bays J H Zarbock R Whitman and T Murphy 2005 Conceptual design and managementof native13 fish refugia on the13 lower13 Colorado13 River In13 CL Spring13 and13 S Leoneditors Proceedings of two symposia Restoring native fish to the lower ColoradoRiver13 interactions13 of native and non-shy‐native13 fishes 13ndash1413 July13 1999 Las13 Vegas13 Nevada13 Restoring13 natural function within a modified riverine environment thelower Colorado River13 8ndash913 July13 1998 U S Fish and13 Wildlife13 Service Southwestern13 Region Albuquerque New Mexico Pages 167-shy‐177

Bertalanffy L Von 1957 Quantitative laws in metabolism13 and growth13 Q Rev Biology 32217 ndash 231

Bingham T B Scheer and C McAda 2003 Propagation facilities in Grand Valley (24 RoadHatchery Horsethief13 Ponds and13 grow-shy‐out ponds) for captive13 rearing13 ofendangered13 fishes for the13 upper13 Colorado13 River basin13 Colorado River RecoveryProgram FY2003 annual project report13 US Fish and13 Wildlife13 Service GrandJunction13 4pp

Birchell G J and K Christopherson 2004 Survival growth and recruitment of larval andjuvenile razorback13 sucker (Xyrauchen texanus) introduced13 into13 floodplain13 depressions13 of the13 Green River Utah13 Final report13 Upper13 Colorado13 RiverEndangered Fish Recovery Program13 Project No C-shy‐6RZ Publication Number 04-shy‐1513 Utah13 Division of Wildlife13 Resources Salt Lake13 City13 Utah13 67 pages

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Brett J R 1979 Environmental Factors and growth pages 599-shy‐67513 InW S Hoar13 D13 J13 Randall and J R Brett (eds) Fish Physiology Volume 8 Bioenergetics and GrowthAcademic Press New York

Brooks J E 1986 Annual reintroduction and monitoring report for razorback suckerXyrauchen texanus in the Gila River Basin Arizona 1985 US Fish and WildlifeService13 Offices of Endangered13 Species and Fishery13 Resources Albuquerque 23 pp

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Brunson13 R E and K D13 Christopherson13 200513 Larval13 razorback13 sucker and bonytailsurvival and13 growth13 in the13 presence13 of nonnative13 fish in the13 Baeser13 floodplainwetland of the middle Green River Final report prepared for Upper13 Colorado RiverBasin Endangered Fish Recovery Program Project No C-shy‐6-shy‐rz-shy‐bt Publication13 No 05-shy‐26 Utah13 Division of Wildlife13 Resources13 Vernal13 32 pp

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Burke13 T13 199513 Rearing13 wild razorback13 sucker larvae in13 lake-shy‐side13 backwaters13 LakeMohave ArizonaNevada Proceedings of the Desert Fishes Council 2635

Busacker G P I R Adelman and E M Goolish13 199013 Growth13 Pages 363 ndash 387 in C BSchreck and p B Moyle editors Methods for fish biology American FisheriesSociety Bethesda Maryland

Castro V B Grisdale-shy‐Helland S J Helland T Kristensen S M Jorgensen J Helgrud13 GClaireaux A P Farrell A Krasnov and H Takle 2011 Aerobic training stimulatesgrowth and promotes disease resistance in Atlantic salmon (Salmo salar)Comparative Biochemistry and Physiology -shy‐ Part A Molecular amp IntegrativePhysiology13 160(2) 278-shy‐290

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Koebele13 B P13 198513 Growth and the size hierarchy effect an experimental assessment ofthree proposed mechanisms activity differences disproportional food acquisition13 pysiological stress Environmental Biology of Fishes 12 181-shy‐188

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Marsh13 P13 C13 1987a13 Digestive tract13 contents13 of adult razorback suckers13 in Lake13 MohaveArizona-shy‐Nevada Transactions of the American Fisheries Society 116117-shy‐119

Marsh P C 1987b Native fishes at Buenos Aires National Wildlife Refuge and ArizonaState University Research Park Arizona opportunities for management researchand public13 education13 on13 endangered species13 Proceedings of the Desert13 FishesCouncil 1967-shy‐78

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Ulibarri M E 2003 Annual report fiscal year 2001 Dexter National Fish Hatchery13 andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 26 pages

Ulibarri M E 2003 Annual report fiscal year 2002 Dexter National Fish Hatchery andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 59 pages

USBR 2006 Lower13 Colorado13 River Multi-shy‐Species Conservation Program final fishaugmentation plan Boulder City 19 pp

USFWS 2002 Razorback sucker (Xyraouchen texanus) recovery goals Amendment andsupplement to the Razorback Sucker Recovery Plan13 US Fish and Wildlife Service13 Region 6 Denver13 Colorado

USFWS 1999 Annual report 1999 Ouray National Fish Hatchery Vernal 25pp

USFWS 2004 Management plan for the big-shy‐river13 fishes of the13 lower13 Colorado13 river basinamendment and supplement to the bonytail humpback chub Coloradopikeminnow and razorback sucker recovery plans

USFWS13 2005 Station13 profile13 of the13 Dexter13 National Fish Hatchery13 and Technology CenterUS Fish and Wildlife13 Service Dexter

Valdez R A P G Mangan R Smith and B Nilson 1982 Upper Colorado River fisheriesinvestigations13 inW H Miller J J Valentine D L Archer H M Tyus R A Valdezand L13 Kaeding13 editors13 Colorado River Fishery13 Project13 Part 2 Field13 investigations13 US Bureau of Reclamation Salt Lake City Utah

WBNFH 2004 Culture methods of the endangered razorback sucker Xyrauchen texanusUS Fish and Wildlife13 Service Willow Beach National Fish Hatchery13 8 pp

Ward D 2008 Effects of disease treatments on growth of razorback sucker ReportSubmitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 Inpartial fulfillment of work task C10 agreement number 06FG30039

Ward13 D13 M Childs and W Persons 2007 Factors13 affecting13 growth13 of razorback sucker13 (Xyrauchen texanus) in captivity Literature review and knowledge assessmentReport Submitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 In partial fulfillment of work task C10 agreement number 06FG30039

57

Appendices

Appendix 1 Survey Questions Survey of Razorback Sucker Culture in the

Southwestern United States

The enclosed survey is being distributed by the Arizona Game and Fish Department to razorback sucker culture facilities throughout

the Southwestern United States The purpose of this survey is to consolidate information regarding culture of this species so that

appropriate facility improvements can be considered for Bubbling Ponds Hatchery in Arizona Specifically we wish to increase

growth rate and production efficiency at the hatchery Information gathered in this survey will be summarized in a final report to US

Bureau of Reclamation in Boulder City NV and disseminated to all facilities that participate in the survey A workshop to discuss

the findings of this study as well as to share general information concerning razorback sucker culture will be organized by the

Arizona Game and Fish Department at the conclusion of this study and all participants will be invited

Thank you for taking the time to fill out this survey Please contact Mike Childs if you have questions or would like to discuss the

survey

Mike Childs

mchildssedonanet

(928) 639-1346

(928) 634-1279

Facility_____________________________________ Date___________________

Contact Phone _____________________________

ContactPerson_______________________________

Contact Email _______________________________

1 Water quality ranges at this culture facility

Season

Spring (Mar-May) Summer (Jun-Aug) Fall (Sept-Nov) Winter (Dec-Feb)

Temperature (C)

PH

DO (mgL)

PO4 (mgL)

TDS (mgL)

Hardness (mgL)

CaCO3

Pathogens

37

13

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Table9Reportedandcalculatedgrowthratesfromtheliterature

Calculatedgrow

thratesbasedon

informationprovidedinliterature

aApproximationsofmaximum

grow

thpotential(basedon

average13 maximum

sizesiffishreportedatharvest

21

13

General Information on Factors that Affect Fish Growth

Growth in fish is extremely variable and is impacted by many different

physiological and environmental factors Growth rates are known to change with size and

age sex season activity level density amount13 of living space quality and quantity of food

genetics and temperature (Brett 1979) Growth experiments conducted at different times

of year can result in growth rates that are not comparable As fish become larger their

physiological13 potential to grow decreases making determination of growth rate dependent

on the size of the starting fish and the length of the experiment (Busacker et al 1990)

Genetic factors also have great potential to influence growth rate Some species have

strains13 and13 races13 that display vastly different growth potentials (Reinitz et al 1979) All of

these factors combine to make assessment of the individual factors controlling fish growth

difficult13

Water temperature is probably the most important variable affecting growth rate13

All of the basic functions that affect growth such as feeding digestion and metabolism are

temperature-shy‐dependent13 Growth13 is inseparably13 tied13 to13 bioenergetics13 and13 therefore13 also13

tightly tied to temperature When temperatures are below optimum daily temperature

fluctuations can stimulate growth Photoperiod is also commonly linked to water

temperature and can influence growth rates in fish (reviewed in Brett 1979)

Fish density13 is known to13 affect growth13 and13 can alter13 growth13 rates13 in several ways13

Fish that exhibit strong territorial behaviors13 or natural schooling tendencies13 will

experience reduced growth if densities are too high or too low (Brett 1979) Dominance

hierarchies where some fish feed more aggressively than others can also lead to high

variability13 in growth13 rates13 (Koebele13 1985) Crowded13 conditions13 also13 cause physical

interference13 between13 fish and13 poor water13 quality13 which13 reduces13 growth13 (Busacker13 et al13

1990) The effects of fish numbers space and feeding opportunity are frequently correlated13

and often13 difficult13 to distinguish (Brett13 1979)13

It is impossible to study the effects of environmental factors on growth without also

evaluating feed rations (Brett 1979) Amount of food quality of the diet particle size

number of feedings per day and time of feeding have all been shown to affect growth

(Busacker et al 1990) In controlled laboratory studies food is usually fed ad libitum13

22

13

(constantly available) and other variables are altered to assess impacts of environmental

factors13 on growth13 These studies13 are13 usually13 conducted13 in tanks13 or raceways13 because13

researchers must verify that food is constantly available to the fish which is difficult to do

in large pond environments where the fish and the bottom13 are often not visible (Busacker13

et al13 1990)

Specific Information13 o Razorback13 Sucker13 Growth

Variable13 growth

Growth in razorback suckers is naturally highly variable and may be a function of

their evolutionary history (USFWS13 2002)13 Minckley (1983) speculated that13 wide size

variation in a single cohort of razorback suckers may be adaptive with fast-shy‐growing13 fish

that13 reproduce at a young13 age surviving13 better in13 high discharge years and slow-shy‐growing13

smaller fish surviving better during drought periods This highly variable growth rate

makes rearing razorback suckers in a production setting difficult because fish from13 a single

cohort do not reach the target stocking size simultaneously One of the major tasks for

aquaculture is to maximize both individual growth and total production13 (Gerking13 1978)13

This becomes more difficult when the species being cultured exhibits highly variable

growth13 rates13 because of genetic influences as is the case with razorback13 suckers13

Razorback13 sucker growth13 is typically very13 rapid13 during13 the first13 year of life13 and then13

declines with age First year growth can be as low as 50 mm and as high as 350 mm (Valdez

et al13 1982 Minckley13 1983 Mueller13 1995) Razorback sucker13 grow rapidly13 for

approximately the first five or six years of life and then growth slows13 (McCarthy13 and13

Minckely 198713 Tyus 199813 Minckley et13 al 1991)13 Growth of older individuals in13 extant13 wild

populations is very13 low (Minckley 198313 Tyus 198813 Modde13 et al 1996)13 Wild growth13 rates

for mature adult fish in Lake Mohave based on PIT tag recaptures were often too small to

be accurately measured for both males and females over the time period of 1987-shy‐199713

(Marsh and Pacey 1998) This information suggest it will take substantially longer to rear

fish to13 increasingly13 larger13 stocking13 sizes (40013 ndash 500 mm TL) than it did to reach the target

size of 300 mm TL

Growth in ponds

23

13

One of the main strategies for maintaining genetic refugia and self-shy‐sustaining13

populations of razorback13 sucker in the lower Colorado13 River basin13 is to rear razorback13

sucker13 larvae13 in production13 ponds until they13 are13 a suitable13 size for stocking13 (USFWS13 2004)

Pond culture has proven useful to promote rapid growth of juvenile razorback suckers

(Kaeding and Osmundson 1989) Marsh (1994) reported that growth rates of razorback

suckers13 reared13 in golf-shy‐course13 ponds exceeded13 the13 best growth13 rates13 obtained13 under

intensive13 culture13 conditions13 at federal hatcheries13 especially13 during the13 first several years13

of life Growth rates in these semi-shy‐natural ponds are also comparable to estimated growth

rates13 of juvenile13 wild13 fish (McCarthy13 and13 Minckley13 1987) Modde13 and13 Haines13 (2005)

reported13 the13 greatest growth13 rates13 in the13 largest and13 deepest floodplains13 with13 the13 greatest

amount of submergent vegetation but excellent growth and survival of fish in a grow-shy‐out

pond is of little value if there is not an efficient way to collect the fish from13 the pond

(Kaeding and Osmundson 1989)

Temperature13

Bulkley and Pimentel (1983) used shuttle boxes in the laboratory to determine a

temperature preference13 for razorback suckers13 of 23-shy‐24degC13 In13 their13 studies13 razorback

suckers were found to avoid temperatures below 118 degC or above 286 degC Razorback

suckers at Bubbling Ponds Hatchery are more active in the spring and feed better as

photoperiod increases even prior to water temperatures rising (Frank Agygos personal

communication) Table 3 briefly summarizes water temperature data from13 each facility

Detailed seasonal water temperature profiles are not currently available for many

razorback grow-shy‐out sites13

Density13

Extensive studies have been conducted on commercially important species to

evaluate stocking densities and feeding rates that maximize production For these species

controlled experiments under laboratory conditions have established relationships

between temperature density and feed ration on growth (Brett 1979) but this information

is sporadic13 or non-shy‐existent for razorback suckers13 (Bays13 et al13 2005) Fish culturists13 with13

24

13

experience13 rearing13 razorback suckers13 typically13 have13 target stocking13 densities13 that13 they use

(Tables13 4 -shy‐ 5) These stocking densities have largely been determined over time by trial

and error These approximate stocking densities provide a good starting point for more

controlled13 types13 of replicated13 pond studies13

Feed ration

Razorback13 suckers are currently13 being13 fed a wide variety13 of prepared diets (Table 7)

that range from13 a slow-shy‐sinking salmon feed manufactured by Silver Cupreg to a spirulina

and krill-shy‐enhanced catfish feed made by Rangenreg Most locations are feeding 20 ndash 50

body13 weight per13 day13 Methods13 for culture13 of razorback sucker13 larvae13 in intensive13 settings13 at

fish hatcheries are well documented (Figiel 2005) and various larval fish diets have been

evaluated13 (Tyus and13 Severson 1990 Severson et al13 1992) but no standardized13 procedures

are used for feeding13 larval13 fish in13 intensive settings13

Razorback sucker larvae are also effectively reared in pond environments using

natural foods supplemented with larval fish diets and survival is high when no predators

are present13 (Mueller 2006)13 Growth rates for larval13 and early juvenile razorback13 suckers

may increase with pond fertilization Diet and physiological studies on wild razorback

suckers indicate that they feed on plankton as well as benthic organisms during their entire

life (Marsh 1987) Artificially fertilizing ponds may greatly increase production capacity

and growth rates for razorback13 sucker (Papoulias and Minckley13 1992) and warrants

further13 investigation13

Handling stress

Handling stress13 has13 been shown to13 influence growth13 rates13 Paukert13 et al (2005)

found that growth of bonytail chub was reduced by 26when compared with controls

after being13 repeatedly13 captured and handled in13 hoop13 nets13 Handling13 effects are likely13 to be

similar for razorback suckers that are repeatedly13 captured and sorted in13 a hatchery13 setting13

Razorback suckers that are handled at Willow Beach National Fish Hatchery will commonly

not eat for two weeks after handling (John Scott personal communication) This creates a

difficult situation13 for production13 facilities because13 fish13 need to be sorted to ensure13 large13

25

13

aggressive fish do not interfere with growth of smaller individuals but frequent handling

and sorting13 causes stress related reductions in13 growth13

Measuring Growth in Captive Fish

Weight is the traditional measure used to estimate growth or production in

aquaculture settings13 Groups of fish are typically13 weighed and an average individual13 weight13

is computed (Busacker et al 1990) Although this method is often logistically the easiest it

may not be the most informative for species with highly variable growth rates like

razorback suckers especially when target lengths must be reached before fish can be

stocked Weight can also be highly influenced by things like stomach fullness or

development of gonads (Busacker et al 1990) Condition factor or relative weight can also

be used to assess growth of fish but these tools may be more robust predictors of fecundity

than of growth (Anderson and Neuman 1996) For some species sexes need to be

distinguished because males and females may differ in morphology (Anderson and

Neumann 1996) Mueller (2006) analyzed growth rates based on PIT tag recaptures of 86

razorback suckers13 in High13 Levee Pond13 and13 found13 that differences13 in growth13 do not appear13

to occur until fish are over 450 mm TL at which time growth rate in males slows while

females continue to grow at a slightly higher rate This would indicate that sex may not be

an important factor to consider when examining growth rates unless the target grow-shy‐out

size is above 450 mm TL

The best measures of growth are often determined from13 the length and weight of

individuals rather than from13 groups of fish (Anderson and Nuemannn 1996) because

individual growth rates give better estimates of confidence and variance (Busacker et13 al

1990) Length frequency analysis or recapture of previously marked individuals of a known

size is likely to yield the most useful information for razorback sucker growth The success

of any of these methods depends on proper sampling procedures that are representative of

the population as a whole (Busacker et al 1990) Sampling methods that are known to be

size-shy‐biased such as trammel nets (Mueller et al 2004) or cast nets should not be used when

trying to measure growth rates13

26

13

Conclusions

For razorback sucker survival is largely associated with stocking size Additional

focused13 research13 is therefore13 needed to13 identify13 ways13 to13 increase13 growth13 rates13 of captive-shy‐

reared13 razorback sucker Growth13 rate13 in fish is controlled13 by many factors including fish

size and age temperature density and feed ration which can all be highly correlated

Growth of razorback suckers is also inherently variable which makes the task of identifying

the key factors that13 affect13 growth in13 captivity even more difficult The focus at most

razorback rearing facilities13 is production so the13 types13 of data that are13 collected13 are13 often

insufficient for detailed13 evaluations13 of individual rearing13 practices13 on growth13 Surveys of

existing13 razorback sucker13 rearing facilities indicate that culture methods vary widely and

the types of growth data13 that13 are collected are not13 standardized13 Replicated studies with

detailed information on rearing location water temperature initial stocking size stocking

density and the sizes of all fish at harvest are needed in order to compare the effects of

individual rearing practices on growth This type of research will ultimately provide both

time and cost-shy‐savings to production facilities by reducing the amount of time necessary13 for

razorback sucker to reach stocking size improving overall production efficiency

Optimum13 rearing densities for razorback sucker larvae and juveniles remain to be

determined Current stocking densities will be very useful as starting point for more

detailed studies and although optimum13 rearing densities are likely to be site-shy‐specific13

replicated studies on density will provide a valuable reference for hatchery managers

Frequency13 of sorting is another13 area that needs13 further13 research Frequent

handling13 and13 sorting13 can13 cause13 stress-shy‐related13 reductions13 in growth but not sorting can

create dominance hierarchies that further reduce growth rates of subordinate individuals

The effects13 of sorting13 on overall fish growth13 in both13 pond and13 intensive13 culture13

environments warrant further investigation Research techniques for these types of

experiments are well understood and typically utilize a matrix of replicate ponds per

variable (Bays et al 2005) In every case accurate and complete records of sampling

procedures and data collection are needed in order to interpret data and make inferences

about13 growth rates (Busacker et13 al 1990)13

27

13

Additional research is also needed to evaluate long-shy‐term13 survival of stocked fish

reared in ponds compared to fish13 reared13 in intensive13 culture13 facilities13 Exercise13

conditioning13 and predator-shy‐recognition training may also increase survival of stocked fish

and be more economically feasible than rearing fish to increasingly larger sizes prior to

stocking13 The success13 of traditional fish hatchery programs is measured largely by the

number of fish stocked but hatchery programs for endangered species must measure

success in terms of long-shy‐term13 survival and species recovery (Brannon 1993 Anders 1998)

A specific list of research recommendations follows

Specific Research13 Recommendations13

bull Use replicated studies13 to establish optimum stocking13 densities13 for ponds13 and

tanks13 that can be used as13 a starting13 point for site specific refinement

bull Determine if sortinggrading13 improves13 overall growth rates13 in both ponds13 and

intensive culture facilities13

bull Investigate the use of artificial fertilizers13 to improve growth of both juvenile

and adult razorback suckers13 in ponds13

bull Determine if the razorback sucker diet gives13 better growth rates13 than cheaper

catfish or salmon feeds

bull Evaluate growth rates13 and production potential of new intensive culture

methods13 such as13 large circular tanks13

bull Evaluate13 long-shy‐term survival of fish produced from raceways13 and circular tanks13

compared to fish reared in ponds13

bull Evaluate more effective means13 of treating13 fish diseases13

bull Evaluate factors13 other than size that may increase post-shy‐stocking13 survival such

as13 exercise conditioning13 predator recognition training or rearing13 under more

natural settings13

28

13

II The Effect of Disease Treatments on Razorback Sucker

Growth

Section13 SummaryFormalin copper sulfate potassium permanganate and13 salt are all chemicals commonly13 used13 to13 treat13 Ichthyophthirius multifiliis outbreaks in captive razorback sucker (Xyrauchen13 texanus) Weexposed 190 juvenile13 razorback suckers (127 ndash 26 mm TL) to13 5 5-shy‐day treatments with13 each13 chemical to evaluate the effects13 these chemicals13 may have on growth Fish grew an average of23513 mm TL13 during the month13 study period Fish treated with formalin grew on average13 29mm TL (03 mmday) while fish treated with copper had the lowest growth averaging 20 mmTL (021 mmday) No significant differences in13 growth were observed among fish treatedwith any of the chemicals compared to untreated fish (pgt005) Reductions in growth13 as aresult of repeated chemical treatments are not likely the cause of differences in growth ratesamong13 facilities that raise razorback suckers Repeated chemical treatments may13 have otherimpacts to overall13 fitness or long-shy‐term survival but13 these effects were not13 evident13 in our study

29

13

Introduction

Preservation13 of razorback sucker13 (Xyrauchen texanus) currently13 depends on captive13

rearing and stocking programs until permanent solutions to factors that prevent wild13

recruitment are found Low survival of stocked razorback suckers (Brooks 1986 Marsh

and Brooks 198913 Marsh and Pacey13 2005) has caused target13 sizes for stocked fish to

steadily increase in efforts to reduce predation mortality (Marsh et al 2005 Schooley and

Marsh 2007) Rearing fish to larger sizes at hatcheries comes with increased costs and

creates the need to evaluate husbandry and rearing practices that may affect fish growth

Formalin copper sulfate potassium13 permanganate and salt are all chemicals

commonly used at razorback sucker rearing facilities to treat outbreaks of the protozoan

parasite13 Ichthyophthirius multifiliis ldquoIchrdquo is one of the most pathenogenic diseases of

cultured13 freshwater13 fishes (Matthews13 2005) and causes large13 losses in captive13 populations13

of endangered razorback sucker Each of these chemicals used to treat Ich only kill the free-shy‐

swimming life stage of the parasite13 requiring13 repeated doses over several13 days depending13

on water temperature These chemicals treatments are needed to prevent loss as a result

of disease outbreaks but the cumulative effects repeated disease treatments have on

growth13 are13 unknown

Copper13 sulfate13 has13 been shown to13 significantly13 reduce13 growth13 of channel catfish13 in

production13 ponds (Rabago-shy‐Castro13 2006) but it is unknown whether13 razorback suckers13

experience similar reduced growth following copper treatment Quantifying the impacts of

disease treatments on growth will help to interpret the wide differences in growth rates

observed13 at various13 razorback sucker13 production13 facilities13 throughout the13 southwest

(Ward et al 2007) If one chemical is found to have less detrimental impacts on growth

than another then it may be preferred for use as a disease treatment We evaluated growth

rates13 of razorback suckers13 under13 replicated13 and13 controlled13 conditions13 to13 assess13 effects13 of

repeated formalin copper sulfate and potassium permanganate and salt treatments on

growth13

Methods

We captured 190 juvenile razorback suckers from13 ponds at Bubbling Ponds Fish

Hatchery AZ using hoop nets or cast nets All fish were of the same age class and

30

13

averaged 179 mm total length (TL) (range13 = 127 ndash 262 mm TL)13 These fish were13 offspring13

of captive13 razorback sucker13 broodstock held13 at Dexter13 National13 Fish Hatchery13 NM13 (2007

year class) All fish were tagged with passive integrated transponder (PIT) tags and

quarantined for one month prior to the experiment to allow fish to recover from13 tagging

and become accustomed to being held in circular tanks

At the beginning of the study all fish were weighed measured and scanned for

individual tag numbers with 19 randomly selected fish placed into each13 of 10 8-shy‐foot

diameter circular tanks (Figure 2)13 Each13 tank contained13 two13 airstones13 and13 an13 individual

biofilter with a recirculating water pump (31 litersminute) that had been operating for

at least 1 month prior to the experiment to allow bacterial colonies to become

established Two tanks were designated as a control and did not receive any chemical

treatments while the other eight tanks received formalin copper sulfate potassium13

permanganate or salt treatments at two week intervals (two tanks per chemical

treatment) Formalin copper sulfate and potassium13 permanganate were treated at 1 part

per million (ppm) and salt was applied at 30 parts per thousand (ppt) These treatment

rates are commonly used to treat13 razorback13 suckers for ich at Bubbling13 Ponds Fish13

hatchery (Frank Agygos personal communication)

Figure 213 Photo ofexperimental tankswith individualbiofilters and aeration

31

13

Each treatment consisted of a series of doses applied on Wednesday Thursday and

Friday with a 90water change between each dose Biofilters were removed from13 all

tanks and held in a separate holding facility during treatments and then replaced on the

Monday following treatments after a 90water change This schedule allowed fish to be

exposed to chemical treatments for 5 consecutive days without water quality deteriorating

This 5-shy‐day chemical treatment was repeated every two weeks from13 July to October (97

days)13 for a total of 5 5-shy‐day treatments Water temperature in the treatment tanks ranged

from13 13degC (55degF) to 32degC (91degF)

Fish were fed a fixed ration of commercial razorback diet (Silvercup 4mm13 pellet)

once daily13 (2 percent body13 weight per day13 as calculated13 by13 average initial fish weight)13

At the end of the experiment all fish were again weighed measured and scanned for

individual tag numbers Growth of fish in each treatment group was compared using

analysis of variance (ANOVA) Any mortalities13 that occurred during the13 study13 were13

replaced with previously quarantined fish of equivalent size to maintain equal densities in

each13 tank13 but growth13 data was13 only13 recorded for fish which13 survived13 the13 entire13

experiment

Results

Fish at the13 start of the experiment averaged 179 mm TL (Range13 = 127 ndash 262 mm)

with no significant differences in fish length among treatment groups (F(4189) = 00183 p

gt 0999 ANOVA) On average fish grew 235 mm TL (024 mmday) during the 3 month

study13 Fish in tanks13 treated with formalin had the highest growth averaging 29 mm TL (03

mmday) while fish in tanks treated with copper had the lowest growth averaging 20 mm

TL (021 mmday) Fish in the control tanks averaged 213 mm TL in growth (022

mmday) (Figure13 3)13 Formalin-shy‐treated fish grew13 significantly faster than13 any other

treatment group but no13 significant differences in growth13 in length13 or weight were13

observed among fish treated with any of the chemicals compared to untreated (control)

fish (pgt005 ANOVA)

32

13

Figure 313 Average growthof razorback suckersexposed to a series of 5 5-shy‐day chemical treatmentsover a 97-shy‐day13 periodError bars representstandard error

Discussion13

Growth13 rates13 observed13 in our study13 (021 ndash 03 mmday) are low compared to those

reported13 in other13 studies13 of razorback sucker13 growth13 (0213 ndash 18 mmday) (Ward et al

2007) Using recirculating water systems for our study required filters to be removed and

replaced during treatments Stress to fish caused by removing and replacing filters within

the tanks as well as repeated water changes may have led to overall higher stress and

reduced growth rates compared to those reported for unconfined fish Growth in fish is

highly variable and is affected by many different physiological and environmental factors

including fish size density temperature amount of space and food (Brett 1979) We

strived to control each of these factors but other factors may have also influenced growth

in our experimental tanks During mid-shy‐summer water temperatures in the treatment

tanks reached 32degC (91degF) At these warm13 temperatures fish are very susceptible to

bacterial13 infections13 The slightly higher growth exhibited by fish in the formalin and

potassium13 permanganate treatments may have been the result of these two chemicals

33

13

being effective at controlling bacterial infections The differences in growth we measured

among treatment groups were not statistically significant and do not appear13 biologically13

meaningful during the relatively short duration of this study (97 days) although the

cumulative effects of slightly reduced growth could be biologically meaningful over longer

time frames

Reductions in growth13 as a result13 o repeated chemical treatments are not likely the

cause of differences in growth rates among facilities that raise razorback suckers

Repeated chemical treatments may have other impacts to overall fitness or long-shy‐term13

survival but these13 effects13 were13 not evident in our study It is more likely that the parasite

outbreaks themselves are the cause of different growth rates among razorback rearing

facilities rather than the chemical treatments used to treat the parasites We recommend

that hatchery managers continue to use the chemicals that are most effective at controlling

ldquoIchrdquo13 at their individual13 facilities

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower Colorado Rive Multi-shy‐species13

Conservation Plan under Work Task C10 We thank Ty Wolters and Tom13 Burke for their

support of this research and Frank Agygos and Dave Billingsly of the Bubbling Ponds Fish

Hatchery13 for their13 technical assistance13 and13 help with13 collecting13 fish

34

13

III13 Razorback Growth Rates at Bubbling Ponds ndash 2009-shy‐2011

Section13 SummaryExperimental studies at Bubbling Ponds Fish Hatchery AZ have strived to understand

factors that affect razorback sucker growth in captivity and identify ways to improve growthrates and maximize size at release Rather than performing experimental studies that wouldrequire major13 rearrangement (and likely reduced production)13 of hatchery operations our13 studies13 used normal variation in production techniques13 and practices13 to isolate factors13 thatmay modify growth rates

Our initial work identified razorback13 growth rates in13 lined ponds at standard fishdensity as 026 to13 028mmday (789 to 843 mmmonth) No significant differences in growthrate were observed among fish that had been in the pond only during the winter13 periodcompared to fish that had been in the pond the entire year indicating that water temperatures13 at Bubbling Ponds are high enough to allow fish to incorporate feed effectively year-shy‐roundHowever these growth rates are lower than most values reported from the literature fromnatural or semi-shy‐natural pond environments No significant differences in13 growth rate wereobserved13 between large and13 small fish13 within the 150 ndash 29 mm TL13 size range Additional worksuggests13 that razorback suckers13 tagged at over 300 mm TL had reduced growth rates (024mmday 73 mmmonth) as would be expected according to a typical Von13 Bertalanfy growthcurve although growth rates13 were only slightly less13 than the average growth rate for thehatchery (027513 mmday 82513 mmmonth)

Sorting13 to13 separate small fish from large fish after the first year of growth is practicedesigned13 to allow smaller fish to ldquocatch uprdquo to larger fish We found that13 this technique doesappear to13 improve growth rates of smaller fish Growth rates of sorted small razorback suckers(029 mmday 87mmmonth)13 were equal to that13 of larger13 fish (028 mmday 8413 mmmonth)indicating that sorting may have helped to offset their original slower growth trajectory

Bubbling Ponds Fish Hatchery grows razorbacks in 6 long deep ponds lined with heavyplastic 2 long deep13 earthen13 (unlined) ponds and three wide shallow earthen ponds The wideshallow ponds13 have historically produced very large fish at low density but have been found tomaintain much lower fish numbers than deeper ponds We found13 that growth13 rates ofrazorbacks kept at high density (4-shy‐700013 fish)13 in a wide shallow pond grew extremely slowly(024 mmday 726 mmmonth) This growth rate is among the slowest of any fish over theyears of our study and demonstrates that13 though the large ponds may produce large fish at lowdensity13 they are unable to overcome high13 fish13 densities

Finally one of the major factors influencing13 fish13 growth13 in hatcheries is disease onemajor summer-shy‐time disease at13 Bubbling Ponds is the ectoparasite Ich (Ichthiopthirusmultifiliis) To investigate the impact Ich has on razorback growth we eradicated fish from thespring and water conveyance ditch that supplies13 water to the hatchery using Rotenone This13 restoration effort was fairly short-shy‐lived (Ich returned to the hatchery within four months) but

35

13

growth13 rates of fish13 reared for four months without Ich present (031 mmday 92 mmmonth)were significantly higher than the following 8 months of growth for those same fish (022mmday 65 mmmonth) This disease-shy‐free growth rate is in fact faster than any13 otherprevious growth rates observed at the hatchery in our study

We conclude that growth rates at the Bubbling Ponds Fish Hatchery are likely as highas possible given the pond densities required to13 meet production goals and the Ich-shy‐infestedwater13 that feeds the facility Sorting practices are successful in helping as many fish as possiblereach stocking length as fast as possible Unlined ponds may be able to grow large fish at lowdensities but whatever factors allow for that growth13 are not able13 to overcome13 high fish densityThus the large lower ponds at Bubbling Ponds may be better utilized via renovation to13 deepenand line them

Disease is the most important factor limiting growth as may be expected to be the caseat many13 hatcheries While the spring renovation was not13 a complete success13 the dramaticreduction of fish populations in that habitat was enough to dramatically13 reduce13 the13 occurrenceof Ich at the hatchery13 Such open spring13 systems feeding a hatchery are a misfortune that canbe expected to transmit disease so we suggest that renovating the spring again to combat13 IchImproved techniques to divert water from13 the springs and more throuough treatment ofstream-shy‐side vegetation may improve the success of chemical treatment Successful renovationwould likely both improve growth rates and reduce chemical costs associated with treating Ichoutbreaks Even13 if complete renovation13 is impossible or impractical an13 effort to reduceinvasive fish density in the springs13 which act a vector for the parasite(and thereby reduce thelikelihood of13 Ich being transmitted into ponds) may still13 show dramatic improvements

36

13

Introduction

Conservation efforts13 for razorback sucker13 (Xyrauchen texanus)13 currently13 depend on

captive rearing and stocking programs Low survival of stocked razorback suckers (Brooks

1986 Marsh13 and13 Brooks13 1989 Marsh13 and13 Pacey13 2005) has13 caused13 target sizes for stocked13

fish to steadily increase in efforts to reduce predation mortality13 (Marsh13 et al13 2005

Schooley and Marsh 2007) Rearing fish to larger sizes at hatcheries comes with increased

costs and creates the need to evaluate husbandry and rearing practices that may affect fish

growth13 We evaluated growth13 rates13 of individual razorback suckers13 in ponds13 at Bubbling

Ponds Fish Hatchery13 using Passive Integrated13 Transponder (PIT) tags13 to13 obtain13 precise

growth information for individual fish so that valid comparisons of growth rates as related

to rearing practices can be made

Due to the critical nature of the razorback sucker stocking program we did not

design experimental studies that would require major rearrangement and potentially

reduce production of hatchery operations Instead our studies used normal variation in

production techniques and practices to isolate factors that may modify growth rates

Though this methodology dramatically limits replication and may limit our ability to

directly13 attribute13 differences in growth13 rates13 to13 the13 variables13 we13 investigate13 we13 were13 able13

to accomplish research goals without altering hatchery operations or impacting

production

From13 2009 through 2011 we conducted a series of observational13 growth13 studies to

determine growth rates of individual razorbacks at Bubbling Ponds The first set of

experiments included13 identifying13 growth13 rates13 in lined13 and13 unlined13 ponds determining

growth13 rates13 of fish at different13 sizes13 in13 relation13 to sorting13 practices and monitoring

razorback growth rates after removing the source of the ectoparasite13 Ich (Ichthiopthirus

multifiliis) from13 the hatchery water source13

Razorback growth rate in lined ponds

Our first growth study documented individual growth rates at normal density in 11

million gallon lined ponds13 over two13 years13 This is the standard13 grow-shy‐out process for

razorbacks13 at Bubbling Ponds We monitored growth of fish for a variety13 of sizes and13 the13

37

13

amount of time in a pond during the growing season These13 data give a snapshot of growth13

rates13 at the13 facility13 and13 provide13 the basis for comparisons throughout our study

Growth rate13 in an unlined pond

In addition13 to 6 ponds lined with heavy plastic13 sheeting13 Bubbling Ponds Fish13

Hatchery maintains two narrow and deep (same dimensions as lined ponds13 Figure13 4)13 and13

three large13 shallow unlined ponds These earthen13 ponds typically have vegetation and

associated aquatic invertebrates that may better simulate natural environments by

providing cover and improved food diversity or quality Therefore these unlined ponds

may be expected to produce higher growth rates and potentially improved survival that is

more similar to growth rates observed in more natural grow-shy‐out facilities13 Historically13 the13

large13 shallow13 ponds have produced very large fish when13 utilized at low13 fish density13 The

narrow13 deep earthen13 ponds are13 used to grow13 fry13 at high density in their first13 year of life

The major downside to unlined ponds is the difficulty in harvesting fish where a lined

pond might take 8-shy‐1013 people13 a half13 day13 to13 harvest13 lined13 ponds13 require13 intensive13 weeding13

to allow seines to be pulled and therefore require many more personnel-shy‐hours13 In addition13

to harvest challenges the shallow earthen ponds tend to suffer from13 dissolved oxygen

crashes during the summer Unlined ponds also may maintain higher13 populations13 of non-shy‐

target species such as bluegill sunfish mosquito fish and bullfrog tadpoles We measured

growth rates of suckers in a large shallow earthen pond for comparison to growth in lined

ponds13

Figure13 4 Lined13 and13 earthen ponds13 of similar dimensions (approx 1000000 gallons first

and second panels) and a large13 shallow13 earthen13 pond (third panel)

38

13

Effect of sorting on growth

Razorback13 suckers13 are13 currently13 sorted13 after their first13 year of growth13 They are13

typically removed from13 one of the13 upper earthen13 ponds and13 split into13 two13 lined13 ponds for

subsequent grow-shy‐out13 The larger13 fish (gt approximately 140 mm) are placed into one pond

and the smaller individuals in another It is possible that the larger fish were more

aggressive or adept13 at taking food so this sorting process is intended to allow smaller fish

to improve their growth rate

Effect of Ich on razorback sucker growth rates

We13 evaluated13 growth13 rates13 of razorback sucker13 in the13 presence13 and absence of the

ectoparasite13 Ich (Ichthiopthirus multifiliis) Ich outbreaks can occur in wild populations13 but

hatcheries13 have13 proven excellent locations13 for Ich because13 of very high fish densities13 which13

facilitate13 the13 transfer13 of Ich13 between13 fish This common fish parasite causes direct mortality13

to razorback13 suckers as well13 as secondary bacterial13 infections13

The open spring and13 ditch13 which13 provides water to the Bubbling13 Ponds Hatchery

has long13 been infested with mosquitofish (Gambusia affinis) that harbor13 the13 Ich parasite13

and allow13 it13 to enter the hatchery with incoming13 water13 The solution13 to13 the13 Ich problem13

was to remove the mosquitofish host using13 Rotenone Razorback13 sucker growth13 rates were13

then tracked in13 the absence of this parasite for 4 months and compared with growth rates

after Ich returned to the pond and from13 previous years

Methods

Razorback growth rate in lined ponds

On May 14 2008 141 razorback suckers were tagged with 12 mm PIT tags (1342

kHz) and placed in Pond 3 (approximately 1100000 gallons13 Figure13 4)13 at Bubbling13 Ponds

Fish Hatchery Fifty-shy‐three of these tags were recovered two months later when a large

Ichthyophthirius multifilis (Ich) outbreak killed many fish in the pond On October 15 2008

an additional13 145 PIT tagged13 fish were13 also placed into Pond13 3 On13 May13 14 2009 Pond13 3

was harvested and a total13 of 141 PIT tagged fish were recovered13 Of the tagged fish13 26 fish

had13 been13 in the13 pond since May13 of 2008 (378 days13 o growth) and 115 had been13 in13 the

39

13 40

pond since October13 15 2008 (211 days13 of growth) Numbers of fish in Pond 3 after the Ich

outbreak and for the majority of the period of growth were between 3 000 and 4000 fish

A Hobotempreg temperature13 logger13 was13 also13 installed13 in Pond 3 one meter below the water

surface13 near13 the13 outflow and13 recorded water temperature every 3 hours to allow analysis

of the effects of water temperature on growth rate (Figure13 5) This Hobotemp data is

representative of other pond temperatures throughout this study

In a second experiment 210 adult13 razorback suckers13 were13 PIT tagged13 on13 May 14

2009 and13 placed13 into13 Pond13 3 upper to13 evaluate13 growth13 rates13 of larger13 razorback suckers13 at

Bubbling13 Ponds Hatchery13 under current13 rearing13 conditions13 Size of these fish at tagging13

was (mean = 285 mm range = 205 ndash 396 mm) These fish remained in the pond for 257

days and were harvested on Jan 25 2010 to provide information on growth rates of larger

razorback suckers13 under13 current rearing conditions

Figure 513 Temperatures (degC) inrearing pond at BubblingPonds Hatchery from July toSept 2009 (top graph)13 andfrom Nov to Dec 2009 (Lowergraph) Temperaturesrecorded with a Hobotempregremote data logger13 every 3hours

13

Growth rate13 in an unlined pond

To document razorback sucker growth in earthen ponds we introduced13 225 tagged13

razorback suckers13 into13 Pond13 1 lower13 (Figure 4) in February 3 2010 Additional tagged fish

from13 other studies were added to the pond throughout the growing season and the density

of 1 lower reached a maximum13 of nearly 7000 fish in early summer 2010 Density was

reduced to approximately 6000 fish by capturing fish with hoop nets on June 3 2010 54 of

these fish were tagged fish and returned to 1 lower after being weighed and measured The

pond was harvested on January13 2713 2011 and a total13 of 254 tagged fish out13 of 4296 fish

total were removed from13 the pond The pond was harvested on January 27 2011 (358 days13

of growth) and the tagged fish were weighed and measured Total number of razorbacks in

the pond at harvest13 was 4296

Effect of sorting practices on growth rates

On March 1113 200913 Pond13 5 upper was13 harvested13 and13 split into13 two13 separate13 groups

Two hundred of the smaller fish (average size = 122 mm TL) were PIT tagged and placed

into13 Pond13 7 upper and13 200 of the13 larger13 fish (average = 160 mm TL) were PIT tagged and

placed int Pond13 8 upper Density13 in Pond13 7 was13 4500 fish and13 in Pond13 8 there13 were13 6500

fish These ponds were then harvested after 1 year and growth rates were compared to

give information on the effects of current sorting practices Hobotempreg temperature

loggers were installed in13 Ponds 7 and13 8 during13 the13 grow-shy‐out period with13 water13

temperature recorded every 2 hours13 (Figure13 6)

Effect of Ich on razorback sucker growth rates

Bubbling Ponds spring was treated with Rotenone (CFT Legumine 5) at a

concentration of 2 ppm13 to remove all mosquitofish from13 the spring The treatment

consisted of two treatments 6 hours in duration on two consecutive days (April 12 -shy‐ 13)

using13 drip13 stations13 and13 backpack sprayers13 followed13 by13 an13 additional 6 hours13 of

detoxification using sodium13 permanganate Although 12 mosquitofish were captured in the

spring pond the week following the treatments subsequent minnow trapping (20 traps

checked13 daily13 for 3 weeks) did not capture any additional fish until August 11 2010 when

41

13

juvenile mosquitofish were again detected in the spring pond Minnow traps have

subsequently been set daily with several hundred individuals removed To evaluate if Ich

was also again present in the spring we captured 15 mosquitofish from13 the spring pond on

three separate days and placed them13 in an aquaria at 25 degC with 5 longfin dace known to be

free of Ich These fish were monitored for 2 weeks with no signs of Ich developing This

indicates that even though mosquitofish have returned to the spring pond the parasite is no

longer present13 although how13 long13 this condition13 will13 persist13 is unknown13

On May 1113 201013 200 juvenile razorback13 suckers were harvested out13 of Pond 5

upper (2009 year Class from13 Dexter National Fish Hatchery) and were PIT tagged and

placed into Pond 8 to evaluate if growth rates at bubbling ponds hatchery have improved

following the renovation of the spring and the removal of the Ich parasite Unfortunately13

on Sept13 8 2010 Ich was13 again13 detected13 in Pond 8 and the pond was immediately seined

and 74 tagged fish were measured to obtain growth information for the 4-shy‐month period

during13 which13 the13 pond13 was13 Ich-shy‐free13

Figure13 6 Temperatures (degC) in rearingponds 7 and 8 at Bubbling Ponds Hatchery13 from March 2009 ndash March 201013 pond 7(top13 graph)13 and13 pond 8 (Lower13 graph)13 Temperatures recorded with a Hobotempregremote data logger every 3 hours

42

13

Results

Growth in Lined Ponds

Razorback suckers13 that had been13 in13 Pond 8 upper for the13 entire13 year13 grew an13

average of 0263 mmday (789 mmmonth) and razorback suckers that had been in the

pond for 7 months (Oct -shy‐ May) grew13 on13 average of 028 mmday (843 mmmonth) (Figure13

7) These growth13 rates13 did not significantly13 differ Fish density13 in Pond 3 during13 the13

majority of the growth period was13 00032 ndash 00036 fishgallon13 Additionally no13 significant

differences in growth rate were observed between fish smaller than 210 mm TL and fish

larger than 210 mm TL when all recaptured fish were combined

We also measured the growth rate of very large fish in a lined pond On Jan13 2513 201013

156 adult fish with PIT tags were recovered from13 Pond 3 upper13 These fish were13 in the13

pond for 257 days and experienced an average13 growth13 rate13 of 024mmday or 73

mmmonth (Figure13 7)13 This growth13 rate13 is slightly13 lower13 than13 the13 average13 growth13 rate13

observed13 at Bubbling13 Ponds Hatchery in other studies (0275 mmday 825 mmmonth)

but may not be biologically meaningful We would expect larger13 fish to13 have13 reduced

growth rates according to a typical Von Bertalanfy growth model (Bertalanffy 1957) but it

appears that13 over the size range we evaluated (300 -shy‐ 450 mm TL) growth rates have not

slowed significantly compared to that of smaller13 fish grown at Bubbling Ponds13 Hatchery

Growth13 of razorback suckers13 is known13 to13 slow as13 fish reach13 larger13 sizes but it appears13 this13

reduced growth rate may not really start to be biologically meaningful at Bubbling Ponds

Hatchery13 until razorback suckers13 exceed 450 mm TL

Growth in unlined ponds

Growth13 rates13 for the13 fish recaptured13 during13 the Pond 1 lower13 thinning13 (120 days13 in

the pond) was 024 plusmn 003 mmday (729 plusmn 090 mmmonth) (Figure13 8)13 Fish13 that were13 in

the pond for nearly the entire year grew13 an13 average13 of 024 plusmn 001 mmday (726 plusmn 027

mmmonth) These growth rates are surprisingly the lowest measured growth rates for

any part of our study and differ significantly from13 every other measured growth rate

except very large13 fish (Figure13 9)13 Separating13 out13 large fish that13 were in13 the pond for the

entire year makes no difference fish that were added to the pond at TL lt300 mm grew

43

13

Gro

wth

Rat

e (m

md

ay)

020

026

032

0244 plusmn 001 mmday (733 plusmn 028 mmmonth) and and those with TL gt= 300 mm at the

start of the experiment grew 022 plusmn 003 mmday (651 plusmn 101 mmmonth)

Razorback Growth Rates in Lined Ponds

Figure 7 Growth ofrazorback suckers in(mmday plusmn standard error)in Pond 8 upper in 2008-shy‐2009 An ANOVA did notdetect any significantdifferences

7 Months Full Year 300+ mm fish

Effects of sorting on growth

One hundred and seventy five tagged razorback suckers were recovered from13 Pond

8 upper13 on March13 24 2010 (378 days13 of growth)13 These were13 the13 larger sorted13 fish (gt140

mm TL) that came out of Pond13 5 on March13 11 2009 One13 hundred and13 twenty13 two13 tagged13

razorback suckers were also recovered from13 Pond13 7 upper on March13 31 2010 (385 days13 of

growth)13 These were13 the13 smaller sorted13 fish (lt140 mm TL) that came out of Pond13 5 on

March 1113 200913 No significant differences in growth rate (mmday) were observed among

larger fish in Pond 8 and smaller fish in Pond 7 (pgt005 ANOVA) (Figure 10)13 indicating

that13 sorting may have helped to offset the original slower growth trajectory of the smaller

fish Temperatures of Ponds 7 and 8 upper remained similar throughout the year13 (Figure

5)

44

13

13

13

Gro

wth

Rat

e (m

md

ay)

Gro

wth

Rat

e (m

md

ay)

020

026

032

020

026

032

Razorback Growth in an Unlined Pond

Figure 8 Growth of razorbacksuckers (mmday plusmn standard error) in Pond 1 lower (an unlined pond)in 2010-shy‐2011 An ANOVA did notdetect any significant differences

6 Months 12 Months lt 300 mm Fish 300+ mm Fish Growth Growth

Lined vs Earthen Ponds 1 year of growth

Figure 9 Growth of razorbacksuckers (mmday plusmn standard error) in lined and unlined ponds A t-shy‐test13 did not detect a significantdifference

Lined Pond Unlined Pond 1 Yr Growth 1 Yr Growth

45

13

Effect of Sorting G

row

th R

ate

(mm

day

) G

row

th R

ate

(mm

day

)

032

020

026

032

020

026

Smaller Fish Larger Fish

Effect of Ich

Figure 10 Average growthof razorback suckers(mmday plusmn standard error)that were size-shy‐sorted intosmall fish (pond 7) and largefish (pond 8) populations At-shy‐test did not detect asignificant difference

Figure 11 Average growth ofrazorback suckers (mmday plusmnstandard error) after Ich wasremovd from the hatcheryrsquos springand after Ich was again detected inthe pond The growth rate withoutIch is significantly higher than boththe rate after Ich and the ourstudyrsquos average annual growth ratein lined ponds (ANOVA p =00003)

Growth without Ich Growth With Ich Average Annual 4 months 4 months Growth Rate

46

13

Effect of Ich on razorback sucker growth rates

Seventy-shy‐four13 tagged13 razorback suckers13 were13 recovered from13 Pond 8 on September

15 2010 These fish had13 been13 in the pond for 4 months and experienced a growth rate of

032 mmday or 97 mmmonth (Figure13 11)13 This growth13 rate13 is significantly higher (p =

005 two sample t-shy‐test) than the mean growth rate for the same group13 of tagged fish after

Ich detection (022 mmday or 65 mmmonth) and significantly higher than any other

individual growth13 rates13 observed13 to13 date13 at Bubbling13 Ponds Hatchery13 (Figure13 11)13 If this13

growth13 rate13 were13 extended throughout13 the entire13 year13 fish on average from13 Ich-shy‐free13 ponds13

would be 16 mm longer than fish from13 ponds infested with Ich Studies conducted at

Bubbling Ponds hatchery in 2008 (Ward 2008) did not reveal any effects of the treatment

chemicals on razorback sucker growth rates so it13 is likely that13 the parasite outbreaks

themselves are causing reducing growth rates rather than the chemicals used to treat the

parasites13

Conclusions

Our results suggest that under typical hatchery operations (maximizing number of

fish produced)13 the growth13 rate13 of razorback13 suckers13 is relatively13 consistent at Bubbling13

Ponds hatchery13 at 02-shy‐03 mmday (6-shy‐9 mmmonth)13 but is lower than growth13 rates13 at

other13 facilities (02 ndash 18 mmday Ward et al 2007)13 This growth13 rate13 has13 been13 constant in

both lined and unlined ponds and at all fish densities we were able to measure To achieve13

growth13 rates13 substantially higher than this will likely require13 significant changes in rearing

practices that may not be practical in order to reach numerical production13 goals

Temperature is a key variable in fish growth but seasonal growth patterns

described13 above13 (Figure13 5) demonstrate that water temperatures are high enough in

winter to maintain razorback growth Differences in water temperature by season

currently13 do not fluctuate more than 10degC at Bubbling Ponds because of the continuous

supply of water flowing through each pond (approx 225 gallonsmin) These high water

flows appear to keep pond temperatures within the thermal preference13 for razorback

suckers13 (1213 -shy‐ 28 degC Bulkley and Pimentel 1983) throughout the entire year with

temperatures rarely dropping13 below 16deg13 C (Figures 513 6)13

47

13

Fish density is another key variable in fish growth and though the number of fish in

a pond during our study ranged from13 3000 to 700013 fish we13 did not find any13 correlation13

between13 density and growth rate13 This might yield two conclusions First13 razorback

growth13 may be changed equally13 by13 densities13 at the13 hatchery13 (ie13 a density13 of 3000 fish in a

pond is as stressful13 for razorbacks as a density13 of 7000 fish) An alternative is that other

factors13 such as disease outbreaks have13 stronger13 control over fish growth13 than13 density13

Fish density13 would13 have13 to13 be13 experimentally manipulated to test13 this13 and hatchery

operations (producing the maximum13 number of fish) prevented our manipulating density13

in ponds for this13 work The trouble with manipulating density demonstrates the difficulties

associated with changing13 hatchery13 practices experimenting with density would have

prevented BPH from13 meeting13 production13 goals Given that the stocking of smaller

razorbacks has met with very little success perhaps BPH goals could be changed from13

producing 12000 fish at 300+ mm per year to a smaller number of very large fish each

year Growing13 fewer13 larger13 fish could potentially be accomplished in the same time frame

as more smaller fish but a better understanding of how density alters growth rate would

be required to be confident13 of this

The very slow growth13 in the13 earthen13 unlined13 Pond 1 lower13 was very surprising We13

had13 anticipated13 that the13 diversified diet13 cover and13 other13 habitat features13 provided by13

unlined ponds would yield dramatically increased growth rates However these traits were

not enough to offset high fish densities and in fact the unlined pond in our study13 suffered

mortality to bring densities down to that observed normally in lined ponds

Our data13 suggest13 that razorbacks13 sucker13 growth13 rates13 are13 higher in lined13 ponds13

However we13 think the reasons13 for the13 very slow growth we observed13 in the13 unlined13 pond13

in our study13 is instead13 linked13 to13 the13 usage13 of Pond 1 lower13 during13 the13 study13 rather13 than13

intrinsic13 slow growth13 in earthen13 ponds First the pond was at extremely high density for at

least part of the study The volume of Pond 1 lower has not been estimated but hatchery

managers suggest 1500-shy‐2000 fish is an appropriate number of individuals so this pond

was at a very high density for much of the experiment Second dissolved oxygen is often

very low in the13 large13 earthen13 ponds during the heat of summer much lower than that of

lined ponds This will both limit the number of fish that can survive in the pond and almost

certainly13 increases stress13 of these13 fish potentially13 reducing growth13 The DO crashes also13

48

13

limit the amount of feed hatchery managers can give fish in these ponds sometimes for

days or weeks at a time which further reduces growth during warm13 weather

Our data13 suggests that13 growth rates at the Bubbling13 Ponds Fish Hatchery are likely

as high as possible given13 the pond densities required to meet production goals and the Ich-shy‐

infested water that feeds the facility Sorting practices are successful in helping as many

fish as possible reach stocking length as fast as possible Unlined ponds may be able to

grow13 large13 fish at low13 densities13 but whatever factors allow13 for that13 growth are not13 able to

overcome high fish density The removal of invasive13 fis that act as13 a host for the13 parasite13

Ich fish from13 the Bubbling13 Ponds spring13 allowed the highest13 growth rate at 032 mmday13

(96 mmmonth) but that growth rate decreased again as Ich re-shy‐infested13 the13 hatchery13

Consistently13 achieving13 growth13 rates13 as high or substantially13 higher than13 this13 will likely13

require13 significant changes in rearing practices that may not be practical in order to13 reach13

numerical production13 goals

Two major changes that might result in higher growth rates are substantially

reducing fish density and modifying the way spring water is delivered to the facility (via

either repeated chemical treatments or enclosed concrete water diversions) to eliminate

Ich from13 the hatchery source water Other potential changes not address by our work

include13 flow-shy‐training razorbacks much previous literature including MSCP-shy‐funded13 work

on razorback suckers13 suggests13 that fish growing13 in flowing water will grow13 faster than fish

in still water (Jorgensen and Jobling 1994) Furthermore there are a wide variety of

potential benefits associated with growing13 fish13 in flowing13 water in addition13 to increased

growth13 rates13 (Davidson13 199713 Castro13 et al13 2011) Another option13 for increasing13 growth13

rates13 include13 changing to13 intensive13 culture13 in large circular13 tanks

Finally given that the stocking of smaller razorbacks has met with very little

success13 perhaps13 BPH13 goals13 could13 be13 changed from13 producing 12000 fish at 300+ mm per

year to a smaller number of very large fish each year Growing fewer larger fish could

potentially be accomplished in the same time frame as more smaller fish but a better

understanding13 of how density13 alters growth13 rate13 would13 be13 required to13 be13 confident of this

49

13

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower13 Colorado13 River Multi-shy‐Species13

Conservation Program13 (LCRMSCP) under Work Task C10 We13 thank Ty Wolters13 Tom13

Burke13 and Eric13 Volkman for their support of this research and Frank Agygos and Dave

Billingsly13 of the Bubbling13 Ponds Fish Hatchery13 for their willingness to participate in13 this

research13 and13 for their technical assistance We also thank the LCRMSCP fish group from13

Boulder City13 NV for their assistance with harvesting13 ponds and tagging13 fish13

50

13

Literature13 CitedAnders P J 1998 Conservation aquaculture and endangered species can objective science13

prevail13 over risk13 anxiety Fisheries 23(11) 28-shy‐31

Anderson R O and R M Nuemann 1996 Length weight and associated structural indicesPages 447 ndash 482 in B R Murphy13 and D13 W Willis13 editors13 Fisheries techniques13 2ndedtion American Fisheries13 Society13 Bethesda13 Maryland

Bain M B J T Finn and H E Brooks 1988 Streamflow regulation and fish communitystructure13 Ecology13 69382-shy‐392

Bays J H Zarbock R Whitman and T Murphy 2005 Conceptual design and managementof native13 fish refugia on the13 lower13 Colorado13 River In13 CL Spring13 and13 S Leoneditors Proceedings of two symposia Restoring native fish to the lower ColoradoRiver13 interactions13 of native and non-shy‐native13 fishes 13ndash1413 July13 1999 Las13 Vegas13 Nevada13 Restoring13 natural function within a modified riverine environment thelower Colorado River13 8ndash913 July13 1998 U S Fish and13 Wildlife13 Service Southwestern13 Region Albuquerque New Mexico Pages 167-shy‐177

Bertalanffy L Von 1957 Quantitative laws in metabolism13 and growth13 Q Rev Biology 32217 ndash 231

Bingham T B Scheer and C McAda 2003 Propagation facilities in Grand Valley (24 RoadHatchery Horsethief13 Ponds and13 grow-shy‐out ponds) for captive13 rearing13 ofendangered13 fishes for the13 upper13 Colorado13 River basin13 Colorado River RecoveryProgram FY2003 annual project report13 US Fish and13 Wildlife13 Service GrandJunction13 4pp

Birchell G J and K Christopherson 2004 Survival growth and recruitment of larval andjuvenile razorback13 sucker (Xyrauchen texanus) introduced13 into13 floodplain13 depressions13 of the13 Green River Utah13 Final report13 Upper13 Colorado13 RiverEndangered Fish Recovery Program13 Project No C-shy‐6RZ Publication Number 04-shy‐1513 Utah13 Division of Wildlife13 Resources Salt Lake13 City13 Utah13 67 pages

Brannon E L 1993 The perpetual oversight of hatchery programs Fishery Research 1819-shy‐27

Brett J R 1979 Environmental Factors and growth pages 599-shy‐67513 InW S Hoar13 D13 J13 Randall and J R Brett (eds) Fish Physiology Volume 8 Bioenergetics and GrowthAcademic Press New York

Brooks J E 1986 Annual reintroduction and monitoring report for razorback suckerXyrauchen texanus in the Gila River Basin Arizona 1985 US Fish and WildlifeService13 Offices of Endangered13 Species and Fishery13 Resources Albuquerque 23 pp

51

13

Brunson13 R E and K D13 Christopherson13 200513 Larval13 razorback13 sucker and bonytailsurvival and13 growth13 in the13 presence13 of nonnative13 fish in the13 Baeser13 floodplainwetland of the middle Green River Final report prepared for Upper13 Colorado RiverBasin Endangered Fish Recovery Program Project No C-shy‐6-shy‐rz-shy‐bt Publication13 No 05-shy‐26 Utah13 Division of Wildlife13 Resources13 Vernal13 32 pp

Bulkley R V and R Pimentel 1983 Temperature preference and avoidance by adultrazorback suckers Transactions of the American Fisheries Society 112601-shy‐607

Burke13 T13 199513 Rearing13 wild razorback13 sucker larvae in13 lake-shy‐side13 backwaters13 LakeMohave ArizonaNevada Proceedings of the Desert Fishes Council 2635

Busacker G P I R Adelman and E M Goolish13 199013 Growth13 Pages 363 ndash 387 in C BSchreck and p B Moyle editors Methods for fish biology American FisheriesSociety Bethesda Maryland

Castro V B Grisdale-shy‐Helland S J Helland T Kristensen S M Jorgensen J Helgrud13 GClaireaux A P Farrell A Krasnov and H Takle 2011 Aerobic training stimulatesgrowth and promotes disease resistance in Atlantic salmon (Salmo salar)Comparative Biochemistry and Physiology -shy‐ Part A Molecular amp IntegrativePhysiology13 160(2) 278-shy‐290

Czapla T E 2002 Facilities plan for the production of endangered fishes to meet statestocking13 plans13 as13 part of the13 Upper13 Colorado13 River Endangered13 Fish RecoveryProgram Upper Colorado River Basin Recovery Implementation Program US Fishand Wildlife Service13 Denver13 9 pp

Davidson W 1997 The effects13 of exercise13 training on teleost fish a review of recentliterature Comput Biochem Physiol 117A67ndash75

Figiel Jr C R 2005 Annual report fiscal year 2004 Willow Beach National13 Fish HatcheryUS Fish and Wildlife13 Service Willow Beach 17 pp

Figiel Jr C R M E Ulibarri G Carmichael J Seals and J N Hanson 2005 Intensive13 fish13 culture of warmwater native fishes at a coldwater fish hatchery Pages 164-shy‐16613 inProceedings of two symposia restoring native fish to the lower Colorado13 River13 interaction13 of native13 and13 non-shy‐native13 fishes July13 13-shy‐1413 1999 Las Vegas Nevada USFish and Wildlife Service Southwest Region Albuquerque New Mexico

Gerking13 S D 1978 Ecology of freshwater fish13 production13 Halstead Press13 New13 York

Gustafson W and Q Bradwisch 2000 Wahweap operation and maintenance -shy‐-shy‐ UtahColorado River Recovery Program FY 2000 annual project report Project No 29cUtah13 Division of Wildlife13 Resources Page AZ 3pp

52

13

Hamman R L 1985 Induced spawning of hatchery-shy‐reared13 razorback sucker ProgressivFish Culturist 47(3) 187-shy‐189

Hanson J N 1996 Annual report fiscal year 1996 Willow Beach National Fish HatcheryUS Fish and Wildlife Service13 Willow Beach 9pp

Irving D S Seversen and M Montagne 2004 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2004 annual project13 report Report No 29b US Fish and13 Wildlife13 Service Vernal 3pp

Jorgensen E H and13 M Jobling 1994 Feeding and13 growth13 of exercised13 and13 unexercised13 juvenile Atlantic salmon in freshwater and performance after transfer to seawaterAquaculture International 2 154-shy‐164

Kaeding L R and D B Osmundson 198913 Colorado13 Squawfish13 and13 razorback sucker grow-shy‐out pond studies as part of conservation measures for the green mountain andRuedi reservoir water sales Final report for agreement number 6-shy‐AA-shy‐60-shy‐00150

Koebele13 B P13 198513 Growth and the size hierarchy effect an experimental assessment ofthree proposed mechanisms activity differences disproportional food acquisition13 pysiological stress Environmental Biology of Fishes 12 181-shy‐188

Kretschmann A E and L L Leslie 2006 Razorback sucker (Xyrauchen texanus) status13 reproduction and recruitment in Senator Wash Reservoir CA Final Report13 to USBurea of Reclamation Cooperative Agreement No 00-shy‐FG-shy‐34-shy‐ 0009 p 32 ArizonaGame and Fish Department Phoenix

Marsh13 P13 C13 1987a13 Digestive tract13 contents13 of adult razorback suckers13 in Lake13 MohaveArizona-shy‐Nevada Transactions of the American Fisheries Society 116117-shy‐119

Marsh P C 1987b Native fishes at Buenos Aires National Wildlife Refuge and ArizonaState University Research Park Arizona opportunities for management researchand public13 education13 on13 endangered species13 Proceedings of the Desert13 FishesCouncil 1967-shy‐78

Marsh P C 1994 Rearing native Colorado River fishes in golf course ponds Arizona StateUniversity Tempe 22 + pages

Marsh13 P13 C13 200013 Fish population13 status and evaluation13 in13 the Cibola13 High Levee PondFinal report agreement number 99-shy‐FG-shy‐30-shy‐00051 US Bureau of ReclamationBoulder City13 Nevada13 20 pages

Marsh P C and C A Pacey 1998 Growth of wild adult razorback suckers13 in Lake13 Mohave13 Arizona-shy‐Nevada13 Final report13 US Bureau of Reclamation Boulder City Nevada 25pages + appendices

53

13

Marsh P C B R Kesner and C A Pacey 2005 Repatriation as s management strategy13 to13 conserve a critically13 imperiled fish species North American Journal of FisheriesManagement 25 547-shy‐556

Marsh P C and C A Pacey 2005 Immiscibility of native and non-shy‐native13 fishes Pages 59-shy‐63 inMJ13 Brouder13 CL13 Springer13 and CS13 Leon13 editors13 Proceedings of two13 symposia Restoring native fish to the lower Colorado River interactions of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 NV and13 Restoring natural13 function within a modified riverine environment the lower Colorado River13 July13 8-shy‐913 1998 Las Vegas NV US Fish and13 Wildlife13 Service Southwest Region AlbuquerqueNew Mexico

Marsh13 P13 C13 and J13 E Brooks13 198913 Predation13 by ictalurid catfishes as a deterrent13 toreestablishment of hatchery-shy‐reared13 razorback sucker The Southwestern Naturalist34188-shy‐195

Matthews R A 2005 Ichthyopthirus multifiliis Fouquet and Ichthyopthirosis infreshwater13 teleosts13 Pages13 159-shy‐218 in Advances in Parasitology volume 59 J RBaker R Muller D Rollinson (eds) Academic Press

McCarthy13 M S and W L Minckley 1987 Age estimation for razorback sucker (PiscesCatostomidae) from13 Lake Mohave Arizona and Nevada Journal of the Arizona-shy‐Nevada Academy of Science 2187-shy‐97

Minckley13 W L13 198313 Status of the razorback13 sucker13 Xyrauchen texanus (Abbot)13 in13 thelower Colorado River basin13 The Southwestern13 Naturalist13 28(2) 165-shy‐187

Minckley13 W L13 199113 Native fished of the Grand Canyon13 region an obituary13 Pages 124-shy‐177 in Colorado River ecology and dam13 management National Academy PressWashington13 DC

Minckley13 C13 O and M LaBarbara13 199913 Report13 on13 native fish grow-shy‐out facilities13 at Cibolaand Imperial National Wildlife Refuges 1993-shy‐199513 US Fish and13 Wildlife Service13 Parker Fishery Resources Office Parker Arizona

Modde13 T13 199613 Juvenile razorback sucker (Xyrauchen texanus) in a managed wetlandadjacent13 to the Green13 River13 Great13 Basin13 Naturalist13 56375-shy‐376

Modde T KP Burnham and E J Wick 1996 Population status of the razorback sucker13 inthe middle Green River (USA) Conservation13 biology 10 110-shy‐119

Modde13 T13 and G13 B Haines13 200513 Survival13 and growth of stocked razorback13 sucker andbonytail in multiple floodplain wetlands of the middle Green River under resetconditions13 Final report prepared for Upper Colorado13 River13 Basin RecoveryImplimentation Program US Fish and Wildlife Service Vernal 66 pp

54

13

Modde T Z H Bowen and D C Kitcheyan 2005 Spatial and temporal use of a spawning13 site in the middle Green River by wild hatchery-shy‐reared13 razorback suckers13 Transactions of the American Fisheries Society 134937-shy‐944

Mueller13 G13 199213 The native fish work13 group13 -shy‐ a multiagency endeavor to improve thestatus of the razorback sucker in Lake Mohave AZ-shy‐NV13 Proceedings of the DesertFishes Council 2369

Mueller G 1995 A program13 for maintaining the razorback sucker in Lake MohaveAmerican Fisheries Society Symposium 15127-shy‐135

Mueller13 G13 200613 Ecology of the bonytail13 and razorback13 sucker and the role of offchannelhabitats13 in their13 recovery Scientific13 investigations13 report 2006-shy‐5065 US GeologicalSurvey13 Denver

Mueller G and E Wick 1998 Testing of golf course ponds at Page Arizona for suitability13 as grow-shy‐out facility for razorback sucker using surplus fish from13 Ouray NationalFish Hatchery National Park Service US Fish and13 Wildlife13 Service and UtahDivision of Wildlife13 Resources 28 pages

Mueller13 G13 and T13 Burke13 200513 Survival13 of young13 razorback13 sucker (Xyrauchen texanus) inrelation to13 stocking rates13 (fishha)13 and13 in the presence13 or absence13 of predatorcommunities in Lake Mohave Arizona-shy‐Nevada13 Pages13 155-shy‐16313 in Proceedings of two13 symposia restoring native fish to the lower Colorado River interaction13 of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 Nevada US Fish and Wildlife13 Service Southwest Region Albuquerque New Mexico

Mueller13 G13 J13 Carpenter13 and P13 C13 Marsh13 200413 Cibola13 High Levee Pond annual report 2004US Geological Survey Fort Collins13 Science Center13 Colorado13 and Arizona StateUniversity Tempe 23 pages

Nesler T P K Christopherson J M Hudson C W McAda F Pfeifer and T E Czapla 2003An integrated stocking plan for razorback sucker bonytail and Colorado13 pikeminnow for the Upper Colorado River Endangered Fish Recovery ProgramAddendum13 to State Stocking Plans Upper Colorado River Basin Recovery13 Implementation Program 12 pp

Papoulias13 D and W13 L Minckley13 1992 Effects13 of foo availability13 on survival and growth13 of larval razorback suckers13 in ponds Transactions of the American Fisheries Society121340-shy‐355

Paukert13 C P D L Ward13 P J Sponholtz13 and K13 D Hilwig13 Effects13 of repeated hoopnetting13 on bonytail chub13 Journal of Freshwater13 Ecology13 20(4) 649-shy‐653

Pfeifer F M13 C Baker13 and M13 Montagne13 199913 Propagation13 facilities13 in the13 Grand Valley13 (24 Road13 Hatchery13 Horsethief13 Ponds and13 grow-shy‐out ponds) for captive rearing of

55

13

endangered13 fishes for the13 Upper Colorado13 River Basin13 Colorado13 River Recovery13 Program FY 99 annual project report Project No 29a13 US Fish and Wildlife Service13 Grand13 Junction13 5pp

Pfeifer F S Seversen and M Montagne 2003 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2003 annual reportProject No 29b13 US Fish and Wildlife13 Service Vernal13 4pp

Rabago-shy‐Castro J L Sanchez13 J G Perez-shy‐Castaneda R and13 Gonzalez-shy‐Gonzlez A 2006Effects of the prophylactic use of Romet-shy‐3013 and13 copper13 sulfate13 on growth13 condition13 and feeding13 indicies in13 channel13 catfish (Ictalurus punctatus) Aquaculture 253 343-shy‐349

Reinitz GL L E Orme and F N Hitzel 1979 Variations of body compositio and growth13 among strains of rainbow trout Transactions of the American Fisheries Society 108204-shy‐207

Ruppert13 J13 B P B Holden13 and P D Abate 1999 Age estimation and growth of razorbacksucker13 Xyrauchen texanus in Lake13 Mead Nevada Proceedings13 of the Desert FishesCouncil 3040

Schnoor K D and J Logan 2002 Operation and maintenance of JW Mumma nativeaquatic13 species restoration facility Colorado Colorado River Recovery Program FY2002 annual project report13 Project No 29d Colorado13 Division of Wildlife Alamosa3pp

Salisbury13 L13 1998 Factors13 affecting razorback13 sucker growth13 in Lake13 Mohave backwaters13 MS Thesis13 Unviersity13 of Nevada13 Las13 Vegas

Schooley J13 D13 and P C13 Marsh13 2007 Stocking of endangerdd13 razorback13 suckers13 in thelower Colorado River Basin13 over three decades 1974-shy‐2004 North American Journalof Fisheries Management 27 43-shy‐51

Severson S H H M Tyus and G B Haines 1992 An evaluation of feeds for raisingrazorback sucker Xyrauchen texanus Journal of Applied Aquaculture 155-shy‐65

Toney D P 1974 Observations13 on the13 propagation13 and13 rearing13 of two13 endangered species13 in a hatchery environment Proceedings of the Annual Conference of the Western13 Association of State Game and Fish Commissions 54 252-shy‐259

Tyus H M13 1998 Razorback sucker13 (Xyrauchen texanus) recovery plan13 University13 ofColorado Center for Limnology Boulder13 76 pages

Tyus H M13 and13 S H Severson 1990 Growth13 and13 survival of larval razorback suckers fedfive formulated diets The Progressive Fish Culturist 52197-shy‐200

56

13

Ulibarri M E 2003 Annual report fiscal year 2001 Dexter National Fish Hatchery13 andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 26 pages

Ulibarri M E 2003 Annual report fiscal year 2002 Dexter National Fish Hatchery andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 59 pages

USBR 2006 Lower13 Colorado13 River Multi-shy‐Species Conservation Program final fishaugmentation plan Boulder City 19 pp

USFWS 2002 Razorback sucker (Xyraouchen texanus) recovery goals Amendment andsupplement to the Razorback Sucker Recovery Plan13 US Fish and Wildlife Service13 Region 6 Denver13 Colorado

USFWS 1999 Annual report 1999 Ouray National Fish Hatchery Vernal 25pp

USFWS 2004 Management plan for the big-shy‐river13 fishes of the13 lower13 Colorado13 river basinamendment and supplement to the bonytail humpback chub Coloradopikeminnow and razorback sucker recovery plans

USFWS13 2005 Station13 profile13 of the13 Dexter13 National Fish Hatchery13 and Technology CenterUS Fish and Wildlife13 Service Dexter

Valdez R A P G Mangan R Smith and B Nilson 1982 Upper Colorado River fisheriesinvestigations13 inW H Miller J J Valentine D L Archer H M Tyus R A Valdezand L13 Kaeding13 editors13 Colorado River Fishery13 Project13 Part 2 Field13 investigations13 US Bureau of Reclamation Salt Lake City Utah

WBNFH 2004 Culture methods of the endangered razorback sucker Xyrauchen texanusUS Fish and Wildlife13 Service Willow Beach National Fish Hatchery13 8 pp

Ward D 2008 Effects of disease treatments on growth of razorback sucker ReportSubmitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 Inpartial fulfillment of work task C10 agreement number 06FG30039

Ward13 D13 M Childs and W Persons 2007 Factors13 affecting13 growth13 of razorback sucker13 (Xyrauchen texanus) in captivity Literature review and knowledge assessmentReport Submitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 In partial fulfillment of work task C10 agreement number 06FG30039

57

Appendices

Appendix 1 Survey Questions Survey of Razorback Sucker Culture in the

Southwestern United States

The enclosed survey is being distributed by the Arizona Game and Fish Department to razorback sucker culture facilities throughout

the Southwestern United States The purpose of this survey is to consolidate information regarding culture of this species so that

appropriate facility improvements can be considered for Bubbling Ponds Hatchery in Arizona Specifically we wish to increase

growth rate and production efficiency at the hatchery Information gathered in this survey will be summarized in a final report to US

Bureau of Reclamation in Boulder City NV and disseminated to all facilities that participate in the survey A workshop to discuss

the findings of this study as well as to share general information concerning razorback sucker culture will be organized by the

Arizona Game and Fish Department at the conclusion of this study and all participants will be invited

Thank you for taking the time to fill out this survey Please contact Mike Childs if you have questions or would like to discuss the

survey

Mike Childs

mchildssedonanet

(928) 639-1346

(928) 634-1279

Facility_____________________________________ Date___________________

Contact Phone _____________________________

ContactPerson_______________________________

Contact Email _______________________________

1 Water quality ranges at this culture facility

Season

Spring (Mar-May) Summer (Jun-Aug) Fall (Sept-Nov) Winter (Dec-Feb)

Temperature (C)

PH

DO (mgL)

PO4 (mgL)

TDS (mgL)

Hardness (mgL)

CaCO3

Pathogens

37

13

General Information on Factors that Affect Fish Growth

Growth in fish is extremely variable and is impacted by many different

physiological and environmental factors Growth rates are known to change with size and

age sex season activity level density amount13 of living space quality and quantity of food

genetics and temperature (Brett 1979) Growth experiments conducted at different times

of year can result in growth rates that are not comparable As fish become larger their

physiological13 potential to grow decreases making determination of growth rate dependent

on the size of the starting fish and the length of the experiment (Busacker et al 1990)

Genetic factors also have great potential to influence growth rate Some species have

strains13 and13 races13 that display vastly different growth potentials (Reinitz et al 1979) All of

these factors combine to make assessment of the individual factors controlling fish growth

difficult13

Water temperature is probably the most important variable affecting growth rate13

All of the basic functions that affect growth such as feeding digestion and metabolism are

temperature-shy‐dependent13 Growth13 is inseparably13 tied13 to13 bioenergetics13 and13 therefore13 also13

tightly tied to temperature When temperatures are below optimum daily temperature

fluctuations can stimulate growth Photoperiod is also commonly linked to water

temperature and can influence growth rates in fish (reviewed in Brett 1979)

Fish density13 is known to13 affect growth13 and13 can alter13 growth13 rates13 in several ways13

Fish that exhibit strong territorial behaviors13 or natural schooling tendencies13 will

experience reduced growth if densities are too high or too low (Brett 1979) Dominance

hierarchies where some fish feed more aggressively than others can also lead to high

variability13 in growth13 rates13 (Koebele13 1985) Crowded13 conditions13 also13 cause physical

interference13 between13 fish and13 poor water13 quality13 which13 reduces13 growth13 (Busacker13 et al13

1990) The effects of fish numbers space and feeding opportunity are frequently correlated13

and often13 difficult13 to distinguish (Brett13 1979)13

It is impossible to study the effects of environmental factors on growth without also

evaluating feed rations (Brett 1979) Amount of food quality of the diet particle size

number of feedings per day and time of feeding have all been shown to affect growth

(Busacker et al 1990) In controlled laboratory studies food is usually fed ad libitum13

22

13

(constantly available) and other variables are altered to assess impacts of environmental

factors13 on growth13 These studies13 are13 usually13 conducted13 in tanks13 or raceways13 because13

researchers must verify that food is constantly available to the fish which is difficult to do

in large pond environments where the fish and the bottom13 are often not visible (Busacker13

et al13 1990)

Specific Information13 o Razorback13 Sucker13 Growth

Variable13 growth

Growth in razorback suckers is naturally highly variable and may be a function of

their evolutionary history (USFWS13 2002)13 Minckley (1983) speculated that13 wide size

variation in a single cohort of razorback suckers may be adaptive with fast-shy‐growing13 fish

that13 reproduce at a young13 age surviving13 better in13 high discharge years and slow-shy‐growing13

smaller fish surviving better during drought periods This highly variable growth rate

makes rearing razorback suckers in a production setting difficult because fish from13 a single

cohort do not reach the target stocking size simultaneously One of the major tasks for

aquaculture is to maximize both individual growth and total production13 (Gerking13 1978)13

This becomes more difficult when the species being cultured exhibits highly variable

growth13 rates13 because of genetic influences as is the case with razorback13 suckers13

Razorback13 sucker growth13 is typically very13 rapid13 during13 the first13 year of life13 and then13

declines with age First year growth can be as low as 50 mm and as high as 350 mm (Valdez

et al13 1982 Minckley13 1983 Mueller13 1995) Razorback sucker13 grow rapidly13 for

approximately the first five or six years of life and then growth slows13 (McCarthy13 and13

Minckely 198713 Tyus 199813 Minckley et13 al 1991)13 Growth of older individuals in13 extant13 wild

populations is very13 low (Minckley 198313 Tyus 198813 Modde13 et al 1996)13 Wild growth13 rates

for mature adult fish in Lake Mohave based on PIT tag recaptures were often too small to

be accurately measured for both males and females over the time period of 1987-shy‐199713

(Marsh and Pacey 1998) This information suggest it will take substantially longer to rear

fish to13 increasingly13 larger13 stocking13 sizes (40013 ndash 500 mm TL) than it did to reach the target

size of 300 mm TL

Growth in ponds

23

13

One of the main strategies for maintaining genetic refugia and self-shy‐sustaining13

populations of razorback13 sucker in the lower Colorado13 River basin13 is to rear razorback13

sucker13 larvae13 in production13 ponds until they13 are13 a suitable13 size for stocking13 (USFWS13 2004)

Pond culture has proven useful to promote rapid growth of juvenile razorback suckers

(Kaeding and Osmundson 1989) Marsh (1994) reported that growth rates of razorback

suckers13 reared13 in golf-shy‐course13 ponds exceeded13 the13 best growth13 rates13 obtained13 under

intensive13 culture13 conditions13 at federal hatcheries13 especially13 during the13 first several years13

of life Growth rates in these semi-shy‐natural ponds are also comparable to estimated growth

rates13 of juvenile13 wild13 fish (McCarthy13 and13 Minckley13 1987) Modde13 and13 Haines13 (2005)

reported13 the13 greatest growth13 rates13 in the13 largest and13 deepest floodplains13 with13 the13 greatest

amount of submergent vegetation but excellent growth and survival of fish in a grow-shy‐out

pond is of little value if there is not an efficient way to collect the fish from13 the pond

(Kaeding and Osmundson 1989)

Temperature13

Bulkley and Pimentel (1983) used shuttle boxes in the laboratory to determine a

temperature preference13 for razorback suckers13 of 23-shy‐24degC13 In13 their13 studies13 razorback

suckers were found to avoid temperatures below 118 degC or above 286 degC Razorback

suckers at Bubbling Ponds Hatchery are more active in the spring and feed better as

photoperiod increases even prior to water temperatures rising (Frank Agygos personal

communication) Table 3 briefly summarizes water temperature data from13 each facility

Detailed seasonal water temperature profiles are not currently available for many

razorback grow-shy‐out sites13

Density13

Extensive studies have been conducted on commercially important species to

evaluate stocking densities and feeding rates that maximize production For these species

controlled experiments under laboratory conditions have established relationships

between temperature density and feed ration on growth (Brett 1979) but this information

is sporadic13 or non-shy‐existent for razorback suckers13 (Bays13 et al13 2005) Fish culturists13 with13

24

13

experience13 rearing13 razorback suckers13 typically13 have13 target stocking13 densities13 that13 they use

(Tables13 4 -shy‐ 5) These stocking densities have largely been determined over time by trial

and error These approximate stocking densities provide a good starting point for more

controlled13 types13 of replicated13 pond studies13

Feed ration

Razorback13 suckers are currently13 being13 fed a wide variety13 of prepared diets (Table 7)

that range from13 a slow-shy‐sinking salmon feed manufactured by Silver Cupreg to a spirulina

and krill-shy‐enhanced catfish feed made by Rangenreg Most locations are feeding 20 ndash 50

body13 weight per13 day13 Methods13 for culture13 of razorback sucker13 larvae13 in intensive13 settings13 at

fish hatcheries are well documented (Figiel 2005) and various larval fish diets have been

evaluated13 (Tyus and13 Severson 1990 Severson et al13 1992) but no standardized13 procedures

are used for feeding13 larval13 fish in13 intensive settings13

Razorback sucker larvae are also effectively reared in pond environments using

natural foods supplemented with larval fish diets and survival is high when no predators

are present13 (Mueller 2006)13 Growth rates for larval13 and early juvenile razorback13 suckers

may increase with pond fertilization Diet and physiological studies on wild razorback

suckers indicate that they feed on plankton as well as benthic organisms during their entire

life (Marsh 1987) Artificially fertilizing ponds may greatly increase production capacity

and growth rates for razorback13 sucker (Papoulias and Minckley13 1992) and warrants

further13 investigation13

Handling stress

Handling stress13 has13 been shown to13 influence growth13 rates13 Paukert13 et al (2005)

found that growth of bonytail chub was reduced by 26when compared with controls

after being13 repeatedly13 captured and handled in13 hoop13 nets13 Handling13 effects are likely13 to be

similar for razorback suckers that are repeatedly13 captured and sorted in13 a hatchery13 setting13

Razorback suckers that are handled at Willow Beach National Fish Hatchery will commonly

not eat for two weeks after handling (John Scott personal communication) This creates a

difficult situation13 for production13 facilities because13 fish13 need to be sorted to ensure13 large13

25

13

aggressive fish do not interfere with growth of smaller individuals but frequent handling

and sorting13 causes stress related reductions in13 growth13

Measuring Growth in Captive Fish

Weight is the traditional measure used to estimate growth or production in

aquaculture settings13 Groups of fish are typically13 weighed and an average individual13 weight13

is computed (Busacker et al 1990) Although this method is often logistically the easiest it

may not be the most informative for species with highly variable growth rates like

razorback suckers especially when target lengths must be reached before fish can be

stocked Weight can also be highly influenced by things like stomach fullness or

development of gonads (Busacker et al 1990) Condition factor or relative weight can also

be used to assess growth of fish but these tools may be more robust predictors of fecundity

than of growth (Anderson and Neuman 1996) For some species sexes need to be

distinguished because males and females may differ in morphology (Anderson and

Neumann 1996) Mueller (2006) analyzed growth rates based on PIT tag recaptures of 86

razorback suckers13 in High13 Levee Pond13 and13 found13 that differences13 in growth13 do not appear13

to occur until fish are over 450 mm TL at which time growth rate in males slows while

females continue to grow at a slightly higher rate This would indicate that sex may not be

an important factor to consider when examining growth rates unless the target grow-shy‐out

size is above 450 mm TL

The best measures of growth are often determined from13 the length and weight of

individuals rather than from13 groups of fish (Anderson and Nuemannn 1996) because

individual growth rates give better estimates of confidence and variance (Busacker et13 al

1990) Length frequency analysis or recapture of previously marked individuals of a known

size is likely to yield the most useful information for razorback sucker growth The success

of any of these methods depends on proper sampling procedures that are representative of

the population as a whole (Busacker et al 1990) Sampling methods that are known to be

size-shy‐biased such as trammel nets (Mueller et al 2004) or cast nets should not be used when

trying to measure growth rates13

26

13

Conclusions

For razorback sucker survival is largely associated with stocking size Additional

focused13 research13 is therefore13 needed to13 identify13 ways13 to13 increase13 growth13 rates13 of captive-shy‐

reared13 razorback sucker Growth13 rate13 in fish is controlled13 by many factors including fish

size and age temperature density and feed ration which can all be highly correlated

Growth of razorback suckers is also inherently variable which makes the task of identifying

the key factors that13 affect13 growth in13 captivity even more difficult The focus at most

razorback rearing facilities13 is production so the13 types13 of data that are13 collected13 are13 often

insufficient for detailed13 evaluations13 of individual rearing13 practices13 on growth13 Surveys of

existing13 razorback sucker13 rearing facilities indicate that culture methods vary widely and

the types of growth data13 that13 are collected are not13 standardized13 Replicated studies with

detailed information on rearing location water temperature initial stocking size stocking

density and the sizes of all fish at harvest are needed in order to compare the effects of

individual rearing practices on growth This type of research will ultimately provide both

time and cost-shy‐savings to production facilities by reducing the amount of time necessary13 for

razorback sucker to reach stocking size improving overall production efficiency

Optimum13 rearing densities for razorback sucker larvae and juveniles remain to be

determined Current stocking densities will be very useful as starting point for more

detailed studies and although optimum13 rearing densities are likely to be site-shy‐specific13

replicated studies on density will provide a valuable reference for hatchery managers

Frequency13 of sorting is another13 area that needs13 further13 research Frequent

handling13 and13 sorting13 can13 cause13 stress-shy‐related13 reductions13 in growth but not sorting can

create dominance hierarchies that further reduce growth rates of subordinate individuals

The effects13 of sorting13 on overall fish growth13 in both13 pond and13 intensive13 culture13

environments warrant further investigation Research techniques for these types of

experiments are well understood and typically utilize a matrix of replicate ponds per

variable (Bays et al 2005) In every case accurate and complete records of sampling

procedures and data collection are needed in order to interpret data and make inferences

about13 growth rates (Busacker et13 al 1990)13

27

13

Additional research is also needed to evaluate long-shy‐term13 survival of stocked fish

reared in ponds compared to fish13 reared13 in intensive13 culture13 facilities13 Exercise13

conditioning13 and predator-shy‐recognition training may also increase survival of stocked fish

and be more economically feasible than rearing fish to increasingly larger sizes prior to

stocking13 The success13 of traditional fish hatchery programs is measured largely by the

number of fish stocked but hatchery programs for endangered species must measure

success in terms of long-shy‐term13 survival and species recovery (Brannon 1993 Anders 1998)

A specific list of research recommendations follows

Specific Research13 Recommendations13

bull Use replicated studies13 to establish optimum stocking13 densities13 for ponds13 and

tanks13 that can be used as13 a starting13 point for site specific refinement

bull Determine if sortinggrading13 improves13 overall growth rates13 in both ponds13 and

intensive culture facilities13

bull Investigate the use of artificial fertilizers13 to improve growth of both juvenile

and adult razorback suckers13 in ponds13

bull Determine if the razorback sucker diet gives13 better growth rates13 than cheaper

catfish or salmon feeds

bull Evaluate growth rates13 and production potential of new intensive culture

methods13 such as13 large circular tanks13

bull Evaluate13 long-shy‐term survival of fish produced from raceways13 and circular tanks13

compared to fish reared in ponds13

bull Evaluate more effective means13 of treating13 fish diseases13

bull Evaluate factors13 other than size that may increase post-shy‐stocking13 survival such

as13 exercise conditioning13 predator recognition training or rearing13 under more

natural settings13

28

13

II The Effect of Disease Treatments on Razorback Sucker

Growth

Section13 SummaryFormalin copper sulfate potassium permanganate and13 salt are all chemicals commonly13 used13 to13 treat13 Ichthyophthirius multifiliis outbreaks in captive razorback sucker (Xyrauchen13 texanus) Weexposed 190 juvenile13 razorback suckers (127 ndash 26 mm TL) to13 5 5-shy‐day treatments with13 each13 chemical to evaluate the effects13 these chemicals13 may have on growth Fish grew an average of23513 mm TL13 during the month13 study period Fish treated with formalin grew on average13 29mm TL (03 mmday) while fish treated with copper had the lowest growth averaging 20 mmTL (021 mmday) No significant differences in13 growth were observed among fish treatedwith any of the chemicals compared to untreated fish (pgt005) Reductions in growth13 as aresult of repeated chemical treatments are not likely the cause of differences in growth ratesamong13 facilities that raise razorback suckers Repeated chemical treatments may13 have otherimpacts to overall13 fitness or long-shy‐term survival but13 these effects were not13 evident13 in our study

29

13

Introduction

Preservation13 of razorback sucker13 (Xyrauchen texanus) currently13 depends on captive13

rearing and stocking programs until permanent solutions to factors that prevent wild13

recruitment are found Low survival of stocked razorback suckers (Brooks 1986 Marsh

and Brooks 198913 Marsh and Pacey13 2005) has caused target13 sizes for stocked fish to

steadily increase in efforts to reduce predation mortality (Marsh et al 2005 Schooley and

Marsh 2007) Rearing fish to larger sizes at hatcheries comes with increased costs and

creates the need to evaluate husbandry and rearing practices that may affect fish growth

Formalin copper sulfate potassium13 permanganate and salt are all chemicals

commonly used at razorback sucker rearing facilities to treat outbreaks of the protozoan

parasite13 Ichthyophthirius multifiliis ldquoIchrdquo is one of the most pathenogenic diseases of

cultured13 freshwater13 fishes (Matthews13 2005) and causes large13 losses in captive13 populations13

of endangered razorback sucker Each of these chemicals used to treat Ich only kill the free-shy‐

swimming life stage of the parasite13 requiring13 repeated doses over several13 days depending13

on water temperature These chemicals treatments are needed to prevent loss as a result

of disease outbreaks but the cumulative effects repeated disease treatments have on

growth13 are13 unknown

Copper13 sulfate13 has13 been shown to13 significantly13 reduce13 growth13 of channel catfish13 in

production13 ponds (Rabago-shy‐Castro13 2006) but it is unknown whether13 razorback suckers13

experience similar reduced growth following copper treatment Quantifying the impacts of

disease treatments on growth will help to interpret the wide differences in growth rates

observed13 at various13 razorback sucker13 production13 facilities13 throughout the13 southwest

(Ward et al 2007) If one chemical is found to have less detrimental impacts on growth

than another then it may be preferred for use as a disease treatment We evaluated growth

rates13 of razorback suckers13 under13 replicated13 and13 controlled13 conditions13 to13 assess13 effects13 of

repeated formalin copper sulfate and potassium permanganate and salt treatments on

growth13

Methods

We captured 190 juvenile razorback suckers from13 ponds at Bubbling Ponds Fish

Hatchery AZ using hoop nets or cast nets All fish were of the same age class and

30

13

averaged 179 mm total length (TL) (range13 = 127 ndash 262 mm TL)13 These fish were13 offspring13

of captive13 razorback sucker13 broodstock held13 at Dexter13 National13 Fish Hatchery13 NM13 (2007

year class) All fish were tagged with passive integrated transponder (PIT) tags and

quarantined for one month prior to the experiment to allow fish to recover from13 tagging

and become accustomed to being held in circular tanks

At the beginning of the study all fish were weighed measured and scanned for

individual tag numbers with 19 randomly selected fish placed into each13 of 10 8-shy‐foot

diameter circular tanks (Figure 2)13 Each13 tank contained13 two13 airstones13 and13 an13 individual

biofilter with a recirculating water pump (31 litersminute) that had been operating for

at least 1 month prior to the experiment to allow bacterial colonies to become

established Two tanks were designated as a control and did not receive any chemical

treatments while the other eight tanks received formalin copper sulfate potassium13

permanganate or salt treatments at two week intervals (two tanks per chemical

treatment) Formalin copper sulfate and potassium13 permanganate were treated at 1 part

per million (ppm) and salt was applied at 30 parts per thousand (ppt) These treatment

rates are commonly used to treat13 razorback13 suckers for ich at Bubbling13 Ponds Fish13

hatchery (Frank Agygos personal communication)

Figure 213 Photo ofexperimental tankswith individualbiofilters and aeration

31

13

Each treatment consisted of a series of doses applied on Wednesday Thursday and

Friday with a 90water change between each dose Biofilters were removed from13 all

tanks and held in a separate holding facility during treatments and then replaced on the

Monday following treatments after a 90water change This schedule allowed fish to be

exposed to chemical treatments for 5 consecutive days without water quality deteriorating

This 5-shy‐day chemical treatment was repeated every two weeks from13 July to October (97

days)13 for a total of 5 5-shy‐day treatments Water temperature in the treatment tanks ranged

from13 13degC (55degF) to 32degC (91degF)

Fish were fed a fixed ration of commercial razorback diet (Silvercup 4mm13 pellet)

once daily13 (2 percent body13 weight per day13 as calculated13 by13 average initial fish weight)13

At the end of the experiment all fish were again weighed measured and scanned for

individual tag numbers Growth of fish in each treatment group was compared using

analysis of variance (ANOVA) Any mortalities13 that occurred during the13 study13 were13

replaced with previously quarantined fish of equivalent size to maintain equal densities in

each13 tank13 but growth13 data was13 only13 recorded for fish which13 survived13 the13 entire13

experiment

Results

Fish at the13 start of the experiment averaged 179 mm TL (Range13 = 127 ndash 262 mm)

with no significant differences in fish length among treatment groups (F(4189) = 00183 p

gt 0999 ANOVA) On average fish grew 235 mm TL (024 mmday) during the 3 month

study13 Fish in tanks13 treated with formalin had the highest growth averaging 29 mm TL (03

mmday) while fish in tanks treated with copper had the lowest growth averaging 20 mm

TL (021 mmday) Fish in the control tanks averaged 213 mm TL in growth (022

mmday) (Figure13 3)13 Formalin-shy‐treated fish grew13 significantly faster than13 any other

treatment group but no13 significant differences in growth13 in length13 or weight were13

observed among fish treated with any of the chemicals compared to untreated (control)

fish (pgt005 ANOVA)

32

13

Figure 313 Average growthof razorback suckersexposed to a series of 5 5-shy‐day chemical treatmentsover a 97-shy‐day13 periodError bars representstandard error

Discussion13

Growth13 rates13 observed13 in our study13 (021 ndash 03 mmday) are low compared to those

reported13 in other13 studies13 of razorback sucker13 growth13 (0213 ndash 18 mmday) (Ward et al

2007) Using recirculating water systems for our study required filters to be removed and

replaced during treatments Stress to fish caused by removing and replacing filters within

the tanks as well as repeated water changes may have led to overall higher stress and

reduced growth rates compared to those reported for unconfined fish Growth in fish is

highly variable and is affected by many different physiological and environmental factors

including fish size density temperature amount of space and food (Brett 1979) We

strived to control each of these factors but other factors may have also influenced growth

in our experimental tanks During mid-shy‐summer water temperatures in the treatment

tanks reached 32degC (91degF) At these warm13 temperatures fish are very susceptible to

bacterial13 infections13 The slightly higher growth exhibited by fish in the formalin and

potassium13 permanganate treatments may have been the result of these two chemicals

33

13

being effective at controlling bacterial infections The differences in growth we measured

among treatment groups were not statistically significant and do not appear13 biologically13

meaningful during the relatively short duration of this study (97 days) although the

cumulative effects of slightly reduced growth could be biologically meaningful over longer

time frames

Reductions in growth13 as a result13 o repeated chemical treatments are not likely the

cause of differences in growth rates among facilities that raise razorback suckers

Repeated chemical treatments may have other impacts to overall fitness or long-shy‐term13

survival but these13 effects13 were13 not evident in our study It is more likely that the parasite

outbreaks themselves are the cause of different growth rates among razorback rearing

facilities rather than the chemical treatments used to treat the parasites We recommend

that hatchery managers continue to use the chemicals that are most effective at controlling

ldquoIchrdquo13 at their individual13 facilities

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower Colorado Rive Multi-shy‐species13

Conservation Plan under Work Task C10 We thank Ty Wolters and Tom13 Burke for their

support of this research and Frank Agygos and Dave Billingsly of the Bubbling Ponds Fish

Hatchery13 for their13 technical assistance13 and13 help with13 collecting13 fish

34

13

III13 Razorback Growth Rates at Bubbling Ponds ndash 2009-shy‐2011

Section13 SummaryExperimental studies at Bubbling Ponds Fish Hatchery AZ have strived to understand

factors that affect razorback sucker growth in captivity and identify ways to improve growthrates and maximize size at release Rather than performing experimental studies that wouldrequire major13 rearrangement (and likely reduced production)13 of hatchery operations our13 studies13 used normal variation in production techniques13 and practices13 to isolate factors13 thatmay modify growth rates

Our initial work identified razorback13 growth rates in13 lined ponds at standard fishdensity as 026 to13 028mmday (789 to 843 mmmonth) No significant differences in growthrate were observed among fish that had been in the pond only during the winter13 periodcompared to fish that had been in the pond the entire year indicating that water temperatures13 at Bubbling Ponds are high enough to allow fish to incorporate feed effectively year-shy‐roundHowever these growth rates are lower than most values reported from the literature fromnatural or semi-shy‐natural pond environments No significant differences in13 growth rate wereobserved13 between large and13 small fish13 within the 150 ndash 29 mm TL13 size range Additional worksuggests13 that razorback suckers13 tagged at over 300 mm TL had reduced growth rates (024mmday 73 mmmonth) as would be expected according to a typical Von13 Bertalanfy growthcurve although growth rates13 were only slightly less13 than the average growth rate for thehatchery (027513 mmday 82513 mmmonth)

Sorting13 to13 separate small fish from large fish after the first year of growth is practicedesigned13 to allow smaller fish to ldquocatch uprdquo to larger fish We found that13 this technique doesappear to13 improve growth rates of smaller fish Growth rates of sorted small razorback suckers(029 mmday 87mmmonth)13 were equal to that13 of larger13 fish (028 mmday 8413 mmmonth)indicating that sorting may have helped to offset their original slower growth trajectory

Bubbling Ponds Fish Hatchery grows razorbacks in 6 long deep ponds lined with heavyplastic 2 long deep13 earthen13 (unlined) ponds and three wide shallow earthen ponds The wideshallow ponds13 have historically produced very large fish at low density but have been found tomaintain much lower fish numbers than deeper ponds We found13 that growth13 rates ofrazorbacks kept at high density (4-shy‐700013 fish)13 in a wide shallow pond grew extremely slowly(024 mmday 726 mmmonth) This growth rate is among the slowest of any fish over theyears of our study and demonstrates that13 though the large ponds may produce large fish at lowdensity13 they are unable to overcome high13 fish13 densities

Finally one of the major factors influencing13 fish13 growth13 in hatcheries is disease onemajor summer-shy‐time disease at13 Bubbling Ponds is the ectoparasite Ich (Ichthiopthirusmultifiliis) To investigate the impact Ich has on razorback growth we eradicated fish from thespring and water conveyance ditch that supplies13 water to the hatchery using Rotenone This13 restoration effort was fairly short-shy‐lived (Ich returned to the hatchery within four months) but

35

13

growth13 rates of fish13 reared for four months without Ich present (031 mmday 92 mmmonth)were significantly higher than the following 8 months of growth for those same fish (022mmday 65 mmmonth) This disease-shy‐free growth rate is in fact faster than any13 otherprevious growth rates observed at the hatchery in our study

We conclude that growth rates at the Bubbling Ponds Fish Hatchery are likely as highas possible given the pond densities required to13 meet production goals and the Ich-shy‐infestedwater13 that feeds the facility Sorting practices are successful in helping as many fish as possiblereach stocking length as fast as possible Unlined ponds may be able to grow large fish at lowdensities but whatever factors allow for that growth13 are not able13 to overcome13 high fish densityThus the large lower ponds at Bubbling Ponds may be better utilized via renovation to13 deepenand line them

Disease is the most important factor limiting growth as may be expected to be the caseat many13 hatcheries While the spring renovation was not13 a complete success13 the dramaticreduction of fish populations in that habitat was enough to dramatically13 reduce13 the13 occurrenceof Ich at the hatchery13 Such open spring13 systems feeding a hatchery are a misfortune that canbe expected to transmit disease so we suggest that renovating the spring again to combat13 IchImproved techniques to divert water from13 the springs and more throuough treatment ofstream-shy‐side vegetation may improve the success of chemical treatment Successful renovationwould likely both improve growth rates and reduce chemical costs associated with treating Ichoutbreaks Even13 if complete renovation13 is impossible or impractical an13 effort to reduceinvasive fish density in the springs13 which act a vector for the parasite(and thereby reduce thelikelihood of13 Ich being transmitted into ponds) may still13 show dramatic improvements

36

13

Introduction

Conservation efforts13 for razorback sucker13 (Xyrauchen texanus)13 currently13 depend on

captive rearing and stocking programs Low survival of stocked razorback suckers (Brooks

1986 Marsh13 and13 Brooks13 1989 Marsh13 and13 Pacey13 2005) has13 caused13 target sizes for stocked13

fish to steadily increase in efforts to reduce predation mortality13 (Marsh13 et al13 2005

Schooley and Marsh 2007) Rearing fish to larger sizes at hatcheries comes with increased

costs and creates the need to evaluate husbandry and rearing practices that may affect fish

growth13 We evaluated growth13 rates13 of individual razorback suckers13 in ponds13 at Bubbling

Ponds Fish Hatchery13 using Passive Integrated13 Transponder (PIT) tags13 to13 obtain13 precise

growth information for individual fish so that valid comparisons of growth rates as related

to rearing practices can be made

Due to the critical nature of the razorback sucker stocking program we did not

design experimental studies that would require major rearrangement and potentially

reduce production of hatchery operations Instead our studies used normal variation in

production techniques and practices to isolate factors that may modify growth rates

Though this methodology dramatically limits replication and may limit our ability to

directly13 attribute13 differences in growth13 rates13 to13 the13 variables13 we13 investigate13 we13 were13 able13

to accomplish research goals without altering hatchery operations or impacting

production

From13 2009 through 2011 we conducted a series of observational13 growth13 studies to

determine growth rates of individual razorbacks at Bubbling Ponds The first set of

experiments included13 identifying13 growth13 rates13 in lined13 and13 unlined13 ponds determining

growth13 rates13 of fish at different13 sizes13 in13 relation13 to sorting13 practices and monitoring

razorback growth rates after removing the source of the ectoparasite13 Ich (Ichthiopthirus

multifiliis) from13 the hatchery water source13

Razorback growth rate in lined ponds

Our first growth study documented individual growth rates at normal density in 11

million gallon lined ponds13 over two13 years13 This is the standard13 grow-shy‐out process for

razorbacks13 at Bubbling Ponds We monitored growth of fish for a variety13 of sizes and13 the13

37

13

amount of time in a pond during the growing season These13 data give a snapshot of growth13

rates13 at the13 facility13 and13 provide13 the basis for comparisons throughout our study

Growth rate13 in an unlined pond

In addition13 to 6 ponds lined with heavy plastic13 sheeting13 Bubbling Ponds Fish13

Hatchery maintains two narrow and deep (same dimensions as lined ponds13 Figure13 4)13 and13

three large13 shallow unlined ponds These earthen13 ponds typically have vegetation and

associated aquatic invertebrates that may better simulate natural environments by

providing cover and improved food diversity or quality Therefore these unlined ponds

may be expected to produce higher growth rates and potentially improved survival that is

more similar to growth rates observed in more natural grow-shy‐out facilities13 Historically13 the13

large13 shallow13 ponds have produced very large fish when13 utilized at low13 fish density13 The

narrow13 deep earthen13 ponds are13 used to grow13 fry13 at high density in their first13 year of life

The major downside to unlined ponds is the difficulty in harvesting fish where a lined

pond might take 8-shy‐1013 people13 a half13 day13 to13 harvest13 lined13 ponds13 require13 intensive13 weeding13

to allow seines to be pulled and therefore require many more personnel-shy‐hours13 In addition13

to harvest challenges the shallow earthen ponds tend to suffer from13 dissolved oxygen

crashes during the summer Unlined ponds also may maintain higher13 populations13 of non-shy‐

target species such as bluegill sunfish mosquito fish and bullfrog tadpoles We measured

growth rates of suckers in a large shallow earthen pond for comparison to growth in lined

ponds13

Figure13 4 Lined13 and13 earthen ponds13 of similar dimensions (approx 1000000 gallons first

and second panels) and a large13 shallow13 earthen13 pond (third panel)

38

13

Effect of sorting on growth

Razorback13 suckers13 are13 currently13 sorted13 after their first13 year of growth13 They are13

typically removed from13 one of the13 upper earthen13 ponds and13 split into13 two13 lined13 ponds for

subsequent grow-shy‐out13 The larger13 fish (gt approximately 140 mm) are placed into one pond

and the smaller individuals in another It is possible that the larger fish were more

aggressive or adept13 at taking food so this sorting process is intended to allow smaller fish

to improve their growth rate

Effect of Ich on razorback sucker growth rates

We13 evaluated13 growth13 rates13 of razorback sucker13 in the13 presence13 and absence of the

ectoparasite13 Ich (Ichthiopthirus multifiliis) Ich outbreaks can occur in wild populations13 but

hatcheries13 have13 proven excellent locations13 for Ich because13 of very high fish densities13 which13

facilitate13 the13 transfer13 of Ich13 between13 fish This common fish parasite causes direct mortality13

to razorback13 suckers as well13 as secondary bacterial13 infections13

The open spring and13 ditch13 which13 provides water to the Bubbling13 Ponds Hatchery

has long13 been infested with mosquitofish (Gambusia affinis) that harbor13 the13 Ich parasite13

and allow13 it13 to enter the hatchery with incoming13 water13 The solution13 to13 the13 Ich problem13

was to remove the mosquitofish host using13 Rotenone Razorback13 sucker growth13 rates were13

then tracked in13 the absence of this parasite for 4 months and compared with growth rates

after Ich returned to the pond and from13 previous years

Methods

Razorback growth rate in lined ponds

On May 14 2008 141 razorback suckers were tagged with 12 mm PIT tags (1342

kHz) and placed in Pond 3 (approximately 1100000 gallons13 Figure13 4)13 at Bubbling13 Ponds

Fish Hatchery Fifty-shy‐three of these tags were recovered two months later when a large

Ichthyophthirius multifilis (Ich) outbreak killed many fish in the pond On October 15 2008

an additional13 145 PIT tagged13 fish were13 also placed into Pond13 3 On13 May13 14 2009 Pond13 3

was harvested and a total13 of 141 PIT tagged fish were recovered13 Of the tagged fish13 26 fish

had13 been13 in the13 pond since May13 of 2008 (378 days13 o growth) and 115 had been13 in13 the

39

13 40

pond since October13 15 2008 (211 days13 of growth) Numbers of fish in Pond 3 after the Ich

outbreak and for the majority of the period of growth were between 3 000 and 4000 fish

A Hobotempreg temperature13 logger13 was13 also13 installed13 in Pond 3 one meter below the water

surface13 near13 the13 outflow and13 recorded water temperature every 3 hours to allow analysis

of the effects of water temperature on growth rate (Figure13 5) This Hobotemp data is

representative of other pond temperatures throughout this study

In a second experiment 210 adult13 razorback suckers13 were13 PIT tagged13 on13 May 14

2009 and13 placed13 into13 Pond13 3 upper to13 evaluate13 growth13 rates13 of larger13 razorback suckers13 at

Bubbling13 Ponds Hatchery13 under current13 rearing13 conditions13 Size of these fish at tagging13

was (mean = 285 mm range = 205 ndash 396 mm) These fish remained in the pond for 257

days and were harvested on Jan 25 2010 to provide information on growth rates of larger

razorback suckers13 under13 current rearing conditions

Figure 513 Temperatures (degC) inrearing pond at BubblingPonds Hatchery from July toSept 2009 (top graph)13 andfrom Nov to Dec 2009 (Lowergraph) Temperaturesrecorded with a Hobotempregremote data logger13 every 3hours

13

Growth rate13 in an unlined pond

To document razorback sucker growth in earthen ponds we introduced13 225 tagged13

razorback suckers13 into13 Pond13 1 lower13 (Figure 4) in February 3 2010 Additional tagged fish

from13 other studies were added to the pond throughout the growing season and the density

of 1 lower reached a maximum13 of nearly 7000 fish in early summer 2010 Density was

reduced to approximately 6000 fish by capturing fish with hoop nets on June 3 2010 54 of

these fish were tagged fish and returned to 1 lower after being weighed and measured The

pond was harvested on January13 2713 2011 and a total13 of 254 tagged fish out13 of 4296 fish

total were removed from13 the pond The pond was harvested on January 27 2011 (358 days13

of growth) and the tagged fish were weighed and measured Total number of razorbacks in

the pond at harvest13 was 4296

Effect of sorting practices on growth rates

On March 1113 200913 Pond13 5 upper was13 harvested13 and13 split into13 two13 separate13 groups

Two hundred of the smaller fish (average size = 122 mm TL) were PIT tagged and placed

into13 Pond13 7 upper and13 200 of the13 larger13 fish (average = 160 mm TL) were PIT tagged and

placed int Pond13 8 upper Density13 in Pond13 7 was13 4500 fish and13 in Pond13 8 there13 were13 6500

fish These ponds were then harvested after 1 year and growth rates were compared to

give information on the effects of current sorting practices Hobotempreg temperature

loggers were installed in13 Ponds 7 and13 8 during13 the13 grow-shy‐out period with13 water13

temperature recorded every 2 hours13 (Figure13 6)

Effect of Ich on razorback sucker growth rates

Bubbling Ponds spring was treated with Rotenone (CFT Legumine 5) at a

concentration of 2 ppm13 to remove all mosquitofish from13 the spring The treatment

consisted of two treatments 6 hours in duration on two consecutive days (April 12 -shy‐ 13)

using13 drip13 stations13 and13 backpack sprayers13 followed13 by13 an13 additional 6 hours13 of

detoxification using sodium13 permanganate Although 12 mosquitofish were captured in the

spring pond the week following the treatments subsequent minnow trapping (20 traps

checked13 daily13 for 3 weeks) did not capture any additional fish until August 11 2010 when

41

13

juvenile mosquitofish were again detected in the spring pond Minnow traps have

subsequently been set daily with several hundred individuals removed To evaluate if Ich

was also again present in the spring we captured 15 mosquitofish from13 the spring pond on

three separate days and placed them13 in an aquaria at 25 degC with 5 longfin dace known to be

free of Ich These fish were monitored for 2 weeks with no signs of Ich developing This

indicates that even though mosquitofish have returned to the spring pond the parasite is no

longer present13 although how13 long13 this condition13 will13 persist13 is unknown13

On May 1113 201013 200 juvenile razorback13 suckers were harvested out13 of Pond 5

upper (2009 year Class from13 Dexter National Fish Hatchery) and were PIT tagged and

placed into Pond 8 to evaluate if growth rates at bubbling ponds hatchery have improved

following the renovation of the spring and the removal of the Ich parasite Unfortunately13

on Sept13 8 2010 Ich was13 again13 detected13 in Pond 8 and the pond was immediately seined

and 74 tagged fish were measured to obtain growth information for the 4-shy‐month period

during13 which13 the13 pond13 was13 Ich-shy‐free13

Figure13 6 Temperatures (degC) in rearingponds 7 and 8 at Bubbling Ponds Hatchery13 from March 2009 ndash March 201013 pond 7(top13 graph)13 and13 pond 8 (Lower13 graph)13 Temperatures recorded with a Hobotempregremote data logger every 3 hours

42

13

Results

Growth in Lined Ponds

Razorback suckers13 that had been13 in13 Pond 8 upper for the13 entire13 year13 grew an13

average of 0263 mmday (789 mmmonth) and razorback suckers that had been in the

pond for 7 months (Oct -shy‐ May) grew13 on13 average of 028 mmday (843 mmmonth) (Figure13

7) These growth13 rates13 did not significantly13 differ Fish density13 in Pond 3 during13 the13

majority of the growth period was13 00032 ndash 00036 fishgallon13 Additionally no13 significant

differences in growth rate were observed between fish smaller than 210 mm TL and fish

larger than 210 mm TL when all recaptured fish were combined

We also measured the growth rate of very large fish in a lined pond On Jan13 2513 201013

156 adult fish with PIT tags were recovered from13 Pond 3 upper13 These fish were13 in the13

pond for 257 days and experienced an average13 growth13 rate13 of 024mmday or 73

mmmonth (Figure13 7)13 This growth13 rate13 is slightly13 lower13 than13 the13 average13 growth13 rate13

observed13 at Bubbling13 Ponds Hatchery in other studies (0275 mmday 825 mmmonth)

but may not be biologically meaningful We would expect larger13 fish to13 have13 reduced

growth rates according to a typical Von Bertalanfy growth model (Bertalanffy 1957) but it

appears that13 over the size range we evaluated (300 -shy‐ 450 mm TL) growth rates have not

slowed significantly compared to that of smaller13 fish grown at Bubbling Ponds13 Hatchery

Growth13 of razorback suckers13 is known13 to13 slow as13 fish reach13 larger13 sizes but it appears13 this13

reduced growth rate may not really start to be biologically meaningful at Bubbling Ponds

Hatchery13 until razorback suckers13 exceed 450 mm TL

Growth in unlined ponds

Growth13 rates13 for the13 fish recaptured13 during13 the Pond 1 lower13 thinning13 (120 days13 in

the pond) was 024 plusmn 003 mmday (729 plusmn 090 mmmonth) (Figure13 8)13 Fish13 that were13 in

the pond for nearly the entire year grew13 an13 average13 of 024 plusmn 001 mmday (726 plusmn 027

mmmonth) These growth rates are surprisingly the lowest measured growth rates for

any part of our study and differ significantly from13 every other measured growth rate

except very large13 fish (Figure13 9)13 Separating13 out13 large fish that13 were in13 the pond for the

entire year makes no difference fish that were added to the pond at TL lt300 mm grew

43

13

Gro

wth

Rat

e (m

md

ay)

020

026

032

0244 plusmn 001 mmday (733 plusmn 028 mmmonth) and and those with TL gt= 300 mm at the

start of the experiment grew 022 plusmn 003 mmday (651 plusmn 101 mmmonth)

Razorback Growth Rates in Lined Ponds

Figure 7 Growth ofrazorback suckers in(mmday plusmn standard error)in Pond 8 upper in 2008-shy‐2009 An ANOVA did notdetect any significantdifferences

7 Months Full Year 300+ mm fish

Effects of sorting on growth

One hundred and seventy five tagged razorback suckers were recovered from13 Pond

8 upper13 on March13 24 2010 (378 days13 of growth)13 These were13 the13 larger sorted13 fish (gt140

mm TL) that came out of Pond13 5 on March13 11 2009 One13 hundred and13 twenty13 two13 tagged13

razorback suckers were also recovered from13 Pond13 7 upper on March13 31 2010 (385 days13 of

growth)13 These were13 the13 smaller sorted13 fish (lt140 mm TL) that came out of Pond13 5 on

March 1113 200913 No significant differences in growth rate (mmday) were observed among

larger fish in Pond 8 and smaller fish in Pond 7 (pgt005 ANOVA) (Figure 10)13 indicating

that13 sorting may have helped to offset the original slower growth trajectory of the smaller

fish Temperatures of Ponds 7 and 8 upper remained similar throughout the year13 (Figure

5)

44

13

13

13

Gro

wth

Rat

e (m

md

ay)

Gro

wth

Rat

e (m

md

ay)

020

026

032

020

026

032

Razorback Growth in an Unlined Pond

Figure 8 Growth of razorbacksuckers (mmday plusmn standard error) in Pond 1 lower (an unlined pond)in 2010-shy‐2011 An ANOVA did notdetect any significant differences

6 Months 12 Months lt 300 mm Fish 300+ mm Fish Growth Growth

Lined vs Earthen Ponds 1 year of growth

Figure 9 Growth of razorbacksuckers (mmday plusmn standard error) in lined and unlined ponds A t-shy‐test13 did not detect a significantdifference

Lined Pond Unlined Pond 1 Yr Growth 1 Yr Growth

45

13

Effect of Sorting G

row

th R

ate

(mm

day

) G

row

th R

ate

(mm

day

)

032

020

026

032

020

026

Smaller Fish Larger Fish

Effect of Ich

Figure 10 Average growthof razorback suckers(mmday plusmn standard error)that were size-shy‐sorted intosmall fish (pond 7) and largefish (pond 8) populations At-shy‐test did not detect asignificant difference

Figure 11 Average growth ofrazorback suckers (mmday plusmnstandard error) after Ich wasremovd from the hatcheryrsquos springand after Ich was again detected inthe pond The growth rate withoutIch is significantly higher than boththe rate after Ich and the ourstudyrsquos average annual growth ratein lined ponds (ANOVA p =00003)

Growth without Ich Growth With Ich Average Annual 4 months 4 months Growth Rate

46

13

Effect of Ich on razorback sucker growth rates

Seventy-shy‐four13 tagged13 razorback suckers13 were13 recovered from13 Pond 8 on September

15 2010 These fish had13 been13 in the pond for 4 months and experienced a growth rate of

032 mmday or 97 mmmonth (Figure13 11)13 This growth13 rate13 is significantly higher (p =

005 two sample t-shy‐test) than the mean growth rate for the same group13 of tagged fish after

Ich detection (022 mmday or 65 mmmonth) and significantly higher than any other

individual growth13 rates13 observed13 to13 date13 at Bubbling13 Ponds Hatchery13 (Figure13 11)13 If this13

growth13 rate13 were13 extended throughout13 the entire13 year13 fish on average from13 Ich-shy‐free13 ponds13

would be 16 mm longer than fish from13 ponds infested with Ich Studies conducted at

Bubbling Ponds hatchery in 2008 (Ward 2008) did not reveal any effects of the treatment

chemicals on razorback sucker growth rates so it13 is likely that13 the parasite outbreaks

themselves are causing reducing growth rates rather than the chemicals used to treat the

parasites13

Conclusions

Our results suggest that under typical hatchery operations (maximizing number of

fish produced)13 the growth13 rate13 of razorback13 suckers13 is relatively13 consistent at Bubbling13

Ponds hatchery13 at 02-shy‐03 mmday (6-shy‐9 mmmonth)13 but is lower than growth13 rates13 at

other13 facilities (02 ndash 18 mmday Ward et al 2007)13 This growth13 rate13 has13 been13 constant in

both lined and unlined ponds and at all fish densities we were able to measure To achieve13

growth13 rates13 substantially higher than this will likely require13 significant changes in rearing

practices that may not be practical in order to reach numerical production13 goals

Temperature is a key variable in fish growth but seasonal growth patterns

described13 above13 (Figure13 5) demonstrate that water temperatures are high enough in

winter to maintain razorback growth Differences in water temperature by season

currently13 do not fluctuate more than 10degC at Bubbling Ponds because of the continuous

supply of water flowing through each pond (approx 225 gallonsmin) These high water

flows appear to keep pond temperatures within the thermal preference13 for razorback

suckers13 (1213 -shy‐ 28 degC Bulkley and Pimentel 1983) throughout the entire year with

temperatures rarely dropping13 below 16deg13 C (Figures 513 6)13

47

13

Fish density is another key variable in fish growth and though the number of fish in

a pond during our study ranged from13 3000 to 700013 fish we13 did not find any13 correlation13

between13 density and growth rate13 This might yield two conclusions First13 razorback

growth13 may be changed equally13 by13 densities13 at the13 hatchery13 (ie13 a density13 of 3000 fish in a

pond is as stressful13 for razorbacks as a density13 of 7000 fish) An alternative is that other

factors13 such as disease outbreaks have13 stronger13 control over fish growth13 than13 density13

Fish density13 would13 have13 to13 be13 experimentally manipulated to test13 this13 and hatchery

operations (producing the maximum13 number of fish) prevented our manipulating density13

in ponds for this13 work The trouble with manipulating density demonstrates the difficulties

associated with changing13 hatchery13 practices experimenting with density would have

prevented BPH from13 meeting13 production13 goals Given that the stocking of smaller

razorbacks has met with very little success perhaps BPH goals could be changed from13

producing 12000 fish at 300+ mm per year to a smaller number of very large fish each

year Growing13 fewer13 larger13 fish could potentially be accomplished in the same time frame

as more smaller fish but a better understanding of how density alters growth rate would

be required to be confident13 of this

The very slow growth13 in the13 earthen13 unlined13 Pond 1 lower13 was very surprising We13

had13 anticipated13 that the13 diversified diet13 cover and13 other13 habitat features13 provided by13

unlined ponds would yield dramatically increased growth rates However these traits were

not enough to offset high fish densities and in fact the unlined pond in our study13 suffered

mortality to bring densities down to that observed normally in lined ponds

Our data13 suggest13 that razorbacks13 sucker13 growth13 rates13 are13 higher in lined13 ponds13

However we13 think the reasons13 for the13 very slow growth we observed13 in the13 unlined13 pond13

in our study13 is instead13 linked13 to13 the13 usage13 of Pond 1 lower13 during13 the13 study13 rather13 than13

intrinsic13 slow growth13 in earthen13 ponds First the pond was at extremely high density for at

least part of the study The volume of Pond 1 lower has not been estimated but hatchery

managers suggest 1500-shy‐2000 fish is an appropriate number of individuals so this pond

was at a very high density for much of the experiment Second dissolved oxygen is often

very low in the13 large13 earthen13 ponds during the heat of summer much lower than that of

lined ponds This will both limit the number of fish that can survive in the pond and almost

certainly13 increases stress13 of these13 fish potentially13 reducing growth13 The DO crashes also13

48

13

limit the amount of feed hatchery managers can give fish in these ponds sometimes for

days or weeks at a time which further reduces growth during warm13 weather

Our data13 suggests that13 growth rates at the Bubbling13 Ponds Fish Hatchery are likely

as high as possible given13 the pond densities required to meet production goals and the Ich-shy‐

infested water that feeds the facility Sorting practices are successful in helping as many

fish as possible reach stocking length as fast as possible Unlined ponds may be able to

grow13 large13 fish at low13 densities13 but whatever factors allow13 for that13 growth are not13 able to

overcome high fish density The removal of invasive13 fis that act as13 a host for the13 parasite13

Ich fish from13 the Bubbling13 Ponds spring13 allowed the highest13 growth rate at 032 mmday13

(96 mmmonth) but that growth rate decreased again as Ich re-shy‐infested13 the13 hatchery13

Consistently13 achieving13 growth13 rates13 as high or substantially13 higher than13 this13 will likely13

require13 significant changes in rearing practices that may not be practical in order to13 reach13

numerical production13 goals

Two major changes that might result in higher growth rates are substantially

reducing fish density and modifying the way spring water is delivered to the facility (via

either repeated chemical treatments or enclosed concrete water diversions) to eliminate

Ich from13 the hatchery source water Other potential changes not address by our work

include13 flow-shy‐training razorbacks much previous literature including MSCP-shy‐funded13 work

on razorback suckers13 suggests13 that fish growing13 in flowing water will grow13 faster than fish

in still water (Jorgensen and Jobling 1994) Furthermore there are a wide variety of

potential benefits associated with growing13 fish13 in flowing13 water in addition13 to increased

growth13 rates13 (Davidson13 199713 Castro13 et al13 2011) Another option13 for increasing13 growth13

rates13 include13 changing to13 intensive13 culture13 in large circular13 tanks

Finally given that the stocking of smaller razorbacks has met with very little

success13 perhaps13 BPH13 goals13 could13 be13 changed from13 producing 12000 fish at 300+ mm per

year to a smaller number of very large fish each year Growing fewer larger fish could

potentially be accomplished in the same time frame as more smaller fish but a better

understanding13 of how density13 alters growth13 rate13 would13 be13 required to13 be13 confident of this

49

13

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower13 Colorado13 River Multi-shy‐Species13

Conservation Program13 (LCRMSCP) under Work Task C10 We13 thank Ty Wolters13 Tom13

Burke13 and Eric13 Volkman for their support of this research and Frank Agygos and Dave

Billingsly13 of the Bubbling13 Ponds Fish Hatchery13 for their willingness to participate in13 this

research13 and13 for their technical assistance We also thank the LCRMSCP fish group from13

Boulder City13 NV for their assistance with harvesting13 ponds and tagging13 fish13

50

13

Literature13 CitedAnders P J 1998 Conservation aquaculture and endangered species can objective science13

prevail13 over risk13 anxiety Fisheries 23(11) 28-shy‐31

Anderson R O and R M Nuemann 1996 Length weight and associated structural indicesPages 447 ndash 482 in B R Murphy13 and D13 W Willis13 editors13 Fisheries techniques13 2ndedtion American Fisheries13 Society13 Bethesda13 Maryland

Bain M B J T Finn and H E Brooks 1988 Streamflow regulation and fish communitystructure13 Ecology13 69382-shy‐392

Bays J H Zarbock R Whitman and T Murphy 2005 Conceptual design and managementof native13 fish refugia on the13 lower13 Colorado13 River In13 CL Spring13 and13 S Leoneditors Proceedings of two symposia Restoring native fish to the lower ColoradoRiver13 interactions13 of native and non-shy‐native13 fishes 13ndash1413 July13 1999 Las13 Vegas13 Nevada13 Restoring13 natural function within a modified riverine environment thelower Colorado River13 8ndash913 July13 1998 U S Fish and13 Wildlife13 Service Southwestern13 Region Albuquerque New Mexico Pages 167-shy‐177

Bertalanffy L Von 1957 Quantitative laws in metabolism13 and growth13 Q Rev Biology 32217 ndash 231

Bingham T B Scheer and C McAda 2003 Propagation facilities in Grand Valley (24 RoadHatchery Horsethief13 Ponds and13 grow-shy‐out ponds) for captive13 rearing13 ofendangered13 fishes for the13 upper13 Colorado13 River basin13 Colorado River RecoveryProgram FY2003 annual project report13 US Fish and13 Wildlife13 Service GrandJunction13 4pp

Birchell G J and K Christopherson 2004 Survival growth and recruitment of larval andjuvenile razorback13 sucker (Xyrauchen texanus) introduced13 into13 floodplain13 depressions13 of the13 Green River Utah13 Final report13 Upper13 Colorado13 RiverEndangered Fish Recovery Program13 Project No C-shy‐6RZ Publication Number 04-shy‐1513 Utah13 Division of Wildlife13 Resources Salt Lake13 City13 Utah13 67 pages

Brannon E L 1993 The perpetual oversight of hatchery programs Fishery Research 1819-shy‐27

Brett J R 1979 Environmental Factors and growth pages 599-shy‐67513 InW S Hoar13 D13 J13 Randall and J R Brett (eds) Fish Physiology Volume 8 Bioenergetics and GrowthAcademic Press New York

Brooks J E 1986 Annual reintroduction and monitoring report for razorback suckerXyrauchen texanus in the Gila River Basin Arizona 1985 US Fish and WildlifeService13 Offices of Endangered13 Species and Fishery13 Resources Albuquerque 23 pp

51

13

Brunson13 R E and K D13 Christopherson13 200513 Larval13 razorback13 sucker and bonytailsurvival and13 growth13 in the13 presence13 of nonnative13 fish in the13 Baeser13 floodplainwetland of the middle Green River Final report prepared for Upper13 Colorado RiverBasin Endangered Fish Recovery Program Project No C-shy‐6-shy‐rz-shy‐bt Publication13 No 05-shy‐26 Utah13 Division of Wildlife13 Resources13 Vernal13 32 pp

Bulkley R V and R Pimentel 1983 Temperature preference and avoidance by adultrazorback suckers Transactions of the American Fisheries Society 112601-shy‐607

Burke13 T13 199513 Rearing13 wild razorback13 sucker larvae in13 lake-shy‐side13 backwaters13 LakeMohave ArizonaNevada Proceedings of the Desert Fishes Council 2635

Busacker G P I R Adelman and E M Goolish13 199013 Growth13 Pages 363 ndash 387 in C BSchreck and p B Moyle editors Methods for fish biology American FisheriesSociety Bethesda Maryland

Castro V B Grisdale-shy‐Helland S J Helland T Kristensen S M Jorgensen J Helgrud13 GClaireaux A P Farrell A Krasnov and H Takle 2011 Aerobic training stimulatesgrowth and promotes disease resistance in Atlantic salmon (Salmo salar)Comparative Biochemistry and Physiology -shy‐ Part A Molecular amp IntegrativePhysiology13 160(2) 278-shy‐290

Czapla T E 2002 Facilities plan for the production of endangered fishes to meet statestocking13 plans13 as13 part of the13 Upper13 Colorado13 River Endangered13 Fish RecoveryProgram Upper Colorado River Basin Recovery Implementation Program US Fishand Wildlife Service13 Denver13 9 pp

Davidson W 1997 The effects13 of exercise13 training on teleost fish a review of recentliterature Comput Biochem Physiol 117A67ndash75

Figiel Jr C R 2005 Annual report fiscal year 2004 Willow Beach National13 Fish HatcheryUS Fish and Wildlife13 Service Willow Beach 17 pp

Figiel Jr C R M E Ulibarri G Carmichael J Seals and J N Hanson 2005 Intensive13 fish13 culture of warmwater native fishes at a coldwater fish hatchery Pages 164-shy‐16613 inProceedings of two symposia restoring native fish to the lower Colorado13 River13 interaction13 of native13 and13 non-shy‐native13 fishes July13 13-shy‐1413 1999 Las Vegas Nevada USFish and Wildlife Service Southwest Region Albuquerque New Mexico

Gerking13 S D 1978 Ecology of freshwater fish13 production13 Halstead Press13 New13 York

Gustafson W and Q Bradwisch 2000 Wahweap operation and maintenance -shy‐-shy‐ UtahColorado River Recovery Program FY 2000 annual project report Project No 29cUtah13 Division of Wildlife13 Resources Page AZ 3pp

52

13

Hamman R L 1985 Induced spawning of hatchery-shy‐reared13 razorback sucker ProgressivFish Culturist 47(3) 187-shy‐189

Hanson J N 1996 Annual report fiscal year 1996 Willow Beach National Fish HatcheryUS Fish and Wildlife Service13 Willow Beach 9pp

Irving D S Seversen and M Montagne 2004 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2004 annual project13 report Report No 29b US Fish and13 Wildlife13 Service Vernal 3pp

Jorgensen E H and13 M Jobling 1994 Feeding and13 growth13 of exercised13 and13 unexercised13 juvenile Atlantic salmon in freshwater and performance after transfer to seawaterAquaculture International 2 154-shy‐164

Kaeding L R and D B Osmundson 198913 Colorado13 Squawfish13 and13 razorback sucker grow-shy‐out pond studies as part of conservation measures for the green mountain andRuedi reservoir water sales Final report for agreement number 6-shy‐AA-shy‐60-shy‐00150

Koebele13 B P13 198513 Growth and the size hierarchy effect an experimental assessment ofthree proposed mechanisms activity differences disproportional food acquisition13 pysiological stress Environmental Biology of Fishes 12 181-shy‐188

Kretschmann A E and L L Leslie 2006 Razorback sucker (Xyrauchen texanus) status13 reproduction and recruitment in Senator Wash Reservoir CA Final Report13 to USBurea of Reclamation Cooperative Agreement No 00-shy‐FG-shy‐34-shy‐ 0009 p 32 ArizonaGame and Fish Department Phoenix

Marsh13 P13 C13 1987a13 Digestive tract13 contents13 of adult razorback suckers13 in Lake13 MohaveArizona-shy‐Nevada Transactions of the American Fisheries Society 116117-shy‐119

Marsh P C 1987b Native fishes at Buenos Aires National Wildlife Refuge and ArizonaState University Research Park Arizona opportunities for management researchand public13 education13 on13 endangered species13 Proceedings of the Desert13 FishesCouncil 1967-shy‐78

Marsh P C 1994 Rearing native Colorado River fishes in golf course ponds Arizona StateUniversity Tempe 22 + pages

Marsh13 P13 C13 200013 Fish population13 status and evaluation13 in13 the Cibola13 High Levee PondFinal report agreement number 99-shy‐FG-shy‐30-shy‐00051 US Bureau of ReclamationBoulder City13 Nevada13 20 pages

Marsh P C and C A Pacey 1998 Growth of wild adult razorback suckers13 in Lake13 Mohave13 Arizona-shy‐Nevada13 Final report13 US Bureau of Reclamation Boulder City Nevada 25pages + appendices

53

13

Marsh P C B R Kesner and C A Pacey 2005 Repatriation as s management strategy13 to13 conserve a critically13 imperiled fish species North American Journal of FisheriesManagement 25 547-shy‐556

Marsh P C and C A Pacey 2005 Immiscibility of native and non-shy‐native13 fishes Pages 59-shy‐63 inMJ13 Brouder13 CL13 Springer13 and CS13 Leon13 editors13 Proceedings of two13 symposia Restoring native fish to the lower Colorado River interactions of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 NV and13 Restoring natural13 function within a modified riverine environment the lower Colorado River13 July13 8-shy‐913 1998 Las Vegas NV US Fish and13 Wildlife13 Service Southwest Region AlbuquerqueNew Mexico

Marsh13 P13 C13 and J13 E Brooks13 198913 Predation13 by ictalurid catfishes as a deterrent13 toreestablishment of hatchery-shy‐reared13 razorback sucker The Southwestern Naturalist34188-shy‐195

Matthews R A 2005 Ichthyopthirus multifiliis Fouquet and Ichthyopthirosis infreshwater13 teleosts13 Pages13 159-shy‐218 in Advances in Parasitology volume 59 J RBaker R Muller D Rollinson (eds) Academic Press

McCarthy13 M S and W L Minckley 1987 Age estimation for razorback sucker (PiscesCatostomidae) from13 Lake Mohave Arizona and Nevada Journal of the Arizona-shy‐Nevada Academy of Science 2187-shy‐97

Minckley13 W L13 198313 Status of the razorback13 sucker13 Xyrauchen texanus (Abbot)13 in13 thelower Colorado River basin13 The Southwestern13 Naturalist13 28(2) 165-shy‐187

Minckley13 W L13 199113 Native fished of the Grand Canyon13 region an obituary13 Pages 124-shy‐177 in Colorado River ecology and dam13 management National Academy PressWashington13 DC

Minckley13 C13 O and M LaBarbara13 199913 Report13 on13 native fish grow-shy‐out facilities13 at Cibolaand Imperial National Wildlife Refuges 1993-shy‐199513 US Fish and13 Wildlife Service13 Parker Fishery Resources Office Parker Arizona

Modde13 T13 199613 Juvenile razorback sucker (Xyrauchen texanus) in a managed wetlandadjacent13 to the Green13 River13 Great13 Basin13 Naturalist13 56375-shy‐376

Modde T KP Burnham and E J Wick 1996 Population status of the razorback sucker13 inthe middle Green River (USA) Conservation13 biology 10 110-shy‐119

Modde13 T13 and G13 B Haines13 200513 Survival13 and growth of stocked razorback13 sucker andbonytail in multiple floodplain wetlands of the middle Green River under resetconditions13 Final report prepared for Upper Colorado13 River13 Basin RecoveryImplimentation Program US Fish and Wildlife Service Vernal 66 pp

54

13

Modde T Z H Bowen and D C Kitcheyan 2005 Spatial and temporal use of a spawning13 site in the middle Green River by wild hatchery-shy‐reared13 razorback suckers13 Transactions of the American Fisheries Society 134937-shy‐944

Mueller13 G13 199213 The native fish work13 group13 -shy‐ a multiagency endeavor to improve thestatus of the razorback sucker in Lake Mohave AZ-shy‐NV13 Proceedings of the DesertFishes Council 2369

Mueller G 1995 A program13 for maintaining the razorback sucker in Lake MohaveAmerican Fisheries Society Symposium 15127-shy‐135

Mueller13 G13 200613 Ecology of the bonytail13 and razorback13 sucker and the role of offchannelhabitats13 in their13 recovery Scientific13 investigations13 report 2006-shy‐5065 US GeologicalSurvey13 Denver

Mueller G and E Wick 1998 Testing of golf course ponds at Page Arizona for suitability13 as grow-shy‐out facility for razorback sucker using surplus fish from13 Ouray NationalFish Hatchery National Park Service US Fish and13 Wildlife13 Service and UtahDivision of Wildlife13 Resources 28 pages

Mueller13 G13 and T13 Burke13 200513 Survival13 of young13 razorback13 sucker (Xyrauchen texanus) inrelation to13 stocking rates13 (fishha)13 and13 in the presence13 or absence13 of predatorcommunities in Lake Mohave Arizona-shy‐Nevada13 Pages13 155-shy‐16313 in Proceedings of two13 symposia restoring native fish to the lower Colorado River interaction13 of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 Nevada US Fish and Wildlife13 Service Southwest Region Albuquerque New Mexico

Mueller13 G13 J13 Carpenter13 and P13 C13 Marsh13 200413 Cibola13 High Levee Pond annual report 2004US Geological Survey Fort Collins13 Science Center13 Colorado13 and Arizona StateUniversity Tempe 23 pages

Nesler T P K Christopherson J M Hudson C W McAda F Pfeifer and T E Czapla 2003An integrated stocking plan for razorback sucker bonytail and Colorado13 pikeminnow for the Upper Colorado River Endangered Fish Recovery ProgramAddendum13 to State Stocking Plans Upper Colorado River Basin Recovery13 Implementation Program 12 pp

Papoulias13 D and W13 L Minckley13 1992 Effects13 of foo availability13 on survival and growth13 of larval razorback suckers13 in ponds Transactions of the American Fisheries Society121340-shy‐355

Paukert13 C P D L Ward13 P J Sponholtz13 and K13 D Hilwig13 Effects13 of repeated hoopnetting13 on bonytail chub13 Journal of Freshwater13 Ecology13 20(4) 649-shy‐653

Pfeifer F M13 C Baker13 and M13 Montagne13 199913 Propagation13 facilities13 in the13 Grand Valley13 (24 Road13 Hatchery13 Horsethief13 Ponds and13 grow-shy‐out ponds) for captive rearing of

55

13

endangered13 fishes for the13 Upper Colorado13 River Basin13 Colorado13 River Recovery13 Program FY 99 annual project report Project No 29a13 US Fish and Wildlife Service13 Grand13 Junction13 5pp

Pfeifer F S Seversen and M Montagne 2003 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2003 annual reportProject No 29b13 US Fish and Wildlife13 Service Vernal13 4pp

Rabago-shy‐Castro J L Sanchez13 J G Perez-shy‐Castaneda R and13 Gonzalez-shy‐Gonzlez A 2006Effects of the prophylactic use of Romet-shy‐3013 and13 copper13 sulfate13 on growth13 condition13 and feeding13 indicies in13 channel13 catfish (Ictalurus punctatus) Aquaculture 253 343-shy‐349

Reinitz GL L E Orme and F N Hitzel 1979 Variations of body compositio and growth13 among strains of rainbow trout Transactions of the American Fisheries Society 108204-shy‐207

Ruppert13 J13 B P B Holden13 and P D Abate 1999 Age estimation and growth of razorbacksucker13 Xyrauchen texanus in Lake13 Mead Nevada Proceedings13 of the Desert FishesCouncil 3040

Schnoor K D and J Logan 2002 Operation and maintenance of JW Mumma nativeaquatic13 species restoration facility Colorado Colorado River Recovery Program FY2002 annual project report13 Project No 29d Colorado13 Division of Wildlife Alamosa3pp

Salisbury13 L13 1998 Factors13 affecting razorback13 sucker growth13 in Lake13 Mohave backwaters13 MS Thesis13 Unviersity13 of Nevada13 Las13 Vegas

Schooley J13 D13 and P C13 Marsh13 2007 Stocking of endangerdd13 razorback13 suckers13 in thelower Colorado River Basin13 over three decades 1974-shy‐2004 North American Journalof Fisheries Management 27 43-shy‐51

Severson S H H M Tyus and G B Haines 1992 An evaluation of feeds for raisingrazorback sucker Xyrauchen texanus Journal of Applied Aquaculture 155-shy‐65

Toney D P 1974 Observations13 on the13 propagation13 and13 rearing13 of two13 endangered species13 in a hatchery environment Proceedings of the Annual Conference of the Western13 Association of State Game and Fish Commissions 54 252-shy‐259

Tyus H M13 1998 Razorback sucker13 (Xyrauchen texanus) recovery plan13 University13 ofColorado Center for Limnology Boulder13 76 pages

Tyus H M13 and13 S H Severson 1990 Growth13 and13 survival of larval razorback suckers fedfive formulated diets The Progressive Fish Culturist 52197-shy‐200

56

13

Ulibarri M E 2003 Annual report fiscal year 2001 Dexter National Fish Hatchery13 andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 26 pages

Ulibarri M E 2003 Annual report fiscal year 2002 Dexter National Fish Hatchery andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 59 pages

USBR 2006 Lower13 Colorado13 River Multi-shy‐Species Conservation Program final fishaugmentation plan Boulder City 19 pp

USFWS 2002 Razorback sucker (Xyraouchen texanus) recovery goals Amendment andsupplement to the Razorback Sucker Recovery Plan13 US Fish and Wildlife Service13 Region 6 Denver13 Colorado

USFWS 1999 Annual report 1999 Ouray National Fish Hatchery Vernal 25pp

USFWS 2004 Management plan for the big-shy‐river13 fishes of the13 lower13 Colorado13 river basinamendment and supplement to the bonytail humpback chub Coloradopikeminnow and razorback sucker recovery plans

USFWS13 2005 Station13 profile13 of the13 Dexter13 National Fish Hatchery13 and Technology CenterUS Fish and Wildlife13 Service Dexter

Valdez R A P G Mangan R Smith and B Nilson 1982 Upper Colorado River fisheriesinvestigations13 inW H Miller J J Valentine D L Archer H M Tyus R A Valdezand L13 Kaeding13 editors13 Colorado River Fishery13 Project13 Part 2 Field13 investigations13 US Bureau of Reclamation Salt Lake City Utah

WBNFH 2004 Culture methods of the endangered razorback sucker Xyrauchen texanusUS Fish and Wildlife13 Service Willow Beach National Fish Hatchery13 8 pp

Ward D 2008 Effects of disease treatments on growth of razorback sucker ReportSubmitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 Inpartial fulfillment of work task C10 agreement number 06FG30039

Ward13 D13 M Childs and W Persons 2007 Factors13 affecting13 growth13 of razorback sucker13 (Xyrauchen texanus) in captivity Literature review and knowledge assessmentReport Submitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 In partial fulfillment of work task C10 agreement number 06FG30039

57

Appendices

Appendix 1 Survey Questions Survey of Razorback Sucker Culture in the

Southwestern United States

The enclosed survey is being distributed by the Arizona Game and Fish Department to razorback sucker culture facilities throughout

the Southwestern United States The purpose of this survey is to consolidate information regarding culture of this species so that

appropriate facility improvements can be considered for Bubbling Ponds Hatchery in Arizona Specifically we wish to increase

growth rate and production efficiency at the hatchery Information gathered in this survey will be summarized in a final report to US

Bureau of Reclamation in Boulder City NV and disseminated to all facilities that participate in the survey A workshop to discuss

the findings of this study as well as to share general information concerning razorback sucker culture will be organized by the

Arizona Game and Fish Department at the conclusion of this study and all participants will be invited

Thank you for taking the time to fill out this survey Please contact Mike Childs if you have questions or would like to discuss the

survey

Mike Childs

mchildssedonanet

(928) 639-1346

(928) 634-1279

Facility_____________________________________ Date___________________

Contact Phone _____________________________

ContactPerson_______________________________

Contact Email _______________________________

1 Water quality ranges at this culture facility

Season

Spring (Mar-May) Summer (Jun-Aug) Fall (Sept-Nov) Winter (Dec-Feb)

Temperature (C)

PH

DO (mgL)

PO4 (mgL)

TDS (mgL)

Hardness (mgL)

CaCO3

Pathogens

37

13

(constantly available) and other variables are altered to assess impacts of environmental

factors13 on growth13 These studies13 are13 usually13 conducted13 in tanks13 or raceways13 because13

researchers must verify that food is constantly available to the fish which is difficult to do

in large pond environments where the fish and the bottom13 are often not visible (Busacker13

et al13 1990)

Specific Information13 o Razorback13 Sucker13 Growth

Variable13 growth

Growth in razorback suckers is naturally highly variable and may be a function of

their evolutionary history (USFWS13 2002)13 Minckley (1983) speculated that13 wide size

variation in a single cohort of razorback suckers may be adaptive with fast-shy‐growing13 fish

that13 reproduce at a young13 age surviving13 better in13 high discharge years and slow-shy‐growing13

smaller fish surviving better during drought periods This highly variable growth rate

makes rearing razorback suckers in a production setting difficult because fish from13 a single

cohort do not reach the target stocking size simultaneously One of the major tasks for

aquaculture is to maximize both individual growth and total production13 (Gerking13 1978)13

This becomes more difficult when the species being cultured exhibits highly variable

growth13 rates13 because of genetic influences as is the case with razorback13 suckers13

Razorback13 sucker growth13 is typically very13 rapid13 during13 the first13 year of life13 and then13

declines with age First year growth can be as low as 50 mm and as high as 350 mm (Valdez

et al13 1982 Minckley13 1983 Mueller13 1995) Razorback sucker13 grow rapidly13 for

approximately the first five or six years of life and then growth slows13 (McCarthy13 and13

Minckely 198713 Tyus 199813 Minckley et13 al 1991)13 Growth of older individuals in13 extant13 wild

populations is very13 low (Minckley 198313 Tyus 198813 Modde13 et al 1996)13 Wild growth13 rates

for mature adult fish in Lake Mohave based on PIT tag recaptures were often too small to

be accurately measured for both males and females over the time period of 1987-shy‐199713

(Marsh and Pacey 1998) This information suggest it will take substantially longer to rear

fish to13 increasingly13 larger13 stocking13 sizes (40013 ndash 500 mm TL) than it did to reach the target

size of 300 mm TL

Growth in ponds

23

13

One of the main strategies for maintaining genetic refugia and self-shy‐sustaining13

populations of razorback13 sucker in the lower Colorado13 River basin13 is to rear razorback13

sucker13 larvae13 in production13 ponds until they13 are13 a suitable13 size for stocking13 (USFWS13 2004)

Pond culture has proven useful to promote rapid growth of juvenile razorback suckers

(Kaeding and Osmundson 1989) Marsh (1994) reported that growth rates of razorback

suckers13 reared13 in golf-shy‐course13 ponds exceeded13 the13 best growth13 rates13 obtained13 under

intensive13 culture13 conditions13 at federal hatcheries13 especially13 during the13 first several years13

of life Growth rates in these semi-shy‐natural ponds are also comparable to estimated growth

rates13 of juvenile13 wild13 fish (McCarthy13 and13 Minckley13 1987) Modde13 and13 Haines13 (2005)

reported13 the13 greatest growth13 rates13 in the13 largest and13 deepest floodplains13 with13 the13 greatest

amount of submergent vegetation but excellent growth and survival of fish in a grow-shy‐out

pond is of little value if there is not an efficient way to collect the fish from13 the pond

(Kaeding and Osmundson 1989)

Temperature13

Bulkley and Pimentel (1983) used shuttle boxes in the laboratory to determine a

temperature preference13 for razorback suckers13 of 23-shy‐24degC13 In13 their13 studies13 razorback

suckers were found to avoid temperatures below 118 degC or above 286 degC Razorback

suckers at Bubbling Ponds Hatchery are more active in the spring and feed better as

photoperiod increases even prior to water temperatures rising (Frank Agygos personal

communication) Table 3 briefly summarizes water temperature data from13 each facility

Detailed seasonal water temperature profiles are not currently available for many

razorback grow-shy‐out sites13

Density13

Extensive studies have been conducted on commercially important species to

evaluate stocking densities and feeding rates that maximize production For these species

controlled experiments under laboratory conditions have established relationships

between temperature density and feed ration on growth (Brett 1979) but this information

is sporadic13 or non-shy‐existent for razorback suckers13 (Bays13 et al13 2005) Fish culturists13 with13

24

13

experience13 rearing13 razorback suckers13 typically13 have13 target stocking13 densities13 that13 they use

(Tables13 4 -shy‐ 5) These stocking densities have largely been determined over time by trial

and error These approximate stocking densities provide a good starting point for more

controlled13 types13 of replicated13 pond studies13

Feed ration

Razorback13 suckers are currently13 being13 fed a wide variety13 of prepared diets (Table 7)

that range from13 a slow-shy‐sinking salmon feed manufactured by Silver Cupreg to a spirulina

and krill-shy‐enhanced catfish feed made by Rangenreg Most locations are feeding 20 ndash 50

body13 weight per13 day13 Methods13 for culture13 of razorback sucker13 larvae13 in intensive13 settings13 at

fish hatcheries are well documented (Figiel 2005) and various larval fish diets have been

evaluated13 (Tyus and13 Severson 1990 Severson et al13 1992) but no standardized13 procedures

are used for feeding13 larval13 fish in13 intensive settings13

Razorback sucker larvae are also effectively reared in pond environments using

natural foods supplemented with larval fish diets and survival is high when no predators

are present13 (Mueller 2006)13 Growth rates for larval13 and early juvenile razorback13 suckers

may increase with pond fertilization Diet and physiological studies on wild razorback

suckers indicate that they feed on plankton as well as benthic organisms during their entire

life (Marsh 1987) Artificially fertilizing ponds may greatly increase production capacity

and growth rates for razorback13 sucker (Papoulias and Minckley13 1992) and warrants

further13 investigation13

Handling stress

Handling stress13 has13 been shown to13 influence growth13 rates13 Paukert13 et al (2005)

found that growth of bonytail chub was reduced by 26when compared with controls

after being13 repeatedly13 captured and handled in13 hoop13 nets13 Handling13 effects are likely13 to be

similar for razorback suckers that are repeatedly13 captured and sorted in13 a hatchery13 setting13

Razorback suckers that are handled at Willow Beach National Fish Hatchery will commonly

not eat for two weeks after handling (John Scott personal communication) This creates a

difficult situation13 for production13 facilities because13 fish13 need to be sorted to ensure13 large13

25

13

aggressive fish do not interfere with growth of smaller individuals but frequent handling

and sorting13 causes stress related reductions in13 growth13

Measuring Growth in Captive Fish

Weight is the traditional measure used to estimate growth or production in

aquaculture settings13 Groups of fish are typically13 weighed and an average individual13 weight13

is computed (Busacker et al 1990) Although this method is often logistically the easiest it

may not be the most informative for species with highly variable growth rates like

razorback suckers especially when target lengths must be reached before fish can be

stocked Weight can also be highly influenced by things like stomach fullness or

development of gonads (Busacker et al 1990) Condition factor or relative weight can also

be used to assess growth of fish but these tools may be more robust predictors of fecundity

than of growth (Anderson and Neuman 1996) For some species sexes need to be

distinguished because males and females may differ in morphology (Anderson and

Neumann 1996) Mueller (2006) analyzed growth rates based on PIT tag recaptures of 86

razorback suckers13 in High13 Levee Pond13 and13 found13 that differences13 in growth13 do not appear13

to occur until fish are over 450 mm TL at which time growth rate in males slows while

females continue to grow at a slightly higher rate This would indicate that sex may not be

an important factor to consider when examining growth rates unless the target grow-shy‐out

size is above 450 mm TL

The best measures of growth are often determined from13 the length and weight of

individuals rather than from13 groups of fish (Anderson and Nuemannn 1996) because

individual growth rates give better estimates of confidence and variance (Busacker et13 al

1990) Length frequency analysis or recapture of previously marked individuals of a known

size is likely to yield the most useful information for razorback sucker growth The success

of any of these methods depends on proper sampling procedures that are representative of

the population as a whole (Busacker et al 1990) Sampling methods that are known to be

size-shy‐biased such as trammel nets (Mueller et al 2004) or cast nets should not be used when

trying to measure growth rates13

26

13

Conclusions

For razorback sucker survival is largely associated with stocking size Additional

focused13 research13 is therefore13 needed to13 identify13 ways13 to13 increase13 growth13 rates13 of captive-shy‐

reared13 razorback sucker Growth13 rate13 in fish is controlled13 by many factors including fish

size and age temperature density and feed ration which can all be highly correlated

Growth of razorback suckers is also inherently variable which makes the task of identifying

the key factors that13 affect13 growth in13 captivity even more difficult The focus at most

razorback rearing facilities13 is production so the13 types13 of data that are13 collected13 are13 often

insufficient for detailed13 evaluations13 of individual rearing13 practices13 on growth13 Surveys of

existing13 razorback sucker13 rearing facilities indicate that culture methods vary widely and

the types of growth data13 that13 are collected are not13 standardized13 Replicated studies with

detailed information on rearing location water temperature initial stocking size stocking

density and the sizes of all fish at harvest are needed in order to compare the effects of

individual rearing practices on growth This type of research will ultimately provide both

time and cost-shy‐savings to production facilities by reducing the amount of time necessary13 for

razorback sucker to reach stocking size improving overall production efficiency

Optimum13 rearing densities for razorback sucker larvae and juveniles remain to be

determined Current stocking densities will be very useful as starting point for more

detailed studies and although optimum13 rearing densities are likely to be site-shy‐specific13

replicated studies on density will provide a valuable reference for hatchery managers

Frequency13 of sorting is another13 area that needs13 further13 research Frequent

handling13 and13 sorting13 can13 cause13 stress-shy‐related13 reductions13 in growth but not sorting can

create dominance hierarchies that further reduce growth rates of subordinate individuals

The effects13 of sorting13 on overall fish growth13 in both13 pond and13 intensive13 culture13

environments warrant further investigation Research techniques for these types of

experiments are well understood and typically utilize a matrix of replicate ponds per

variable (Bays et al 2005) In every case accurate and complete records of sampling

procedures and data collection are needed in order to interpret data and make inferences

about13 growth rates (Busacker et13 al 1990)13

27

13

Additional research is also needed to evaluate long-shy‐term13 survival of stocked fish

reared in ponds compared to fish13 reared13 in intensive13 culture13 facilities13 Exercise13

conditioning13 and predator-shy‐recognition training may also increase survival of stocked fish

and be more economically feasible than rearing fish to increasingly larger sizes prior to

stocking13 The success13 of traditional fish hatchery programs is measured largely by the

number of fish stocked but hatchery programs for endangered species must measure

success in terms of long-shy‐term13 survival and species recovery (Brannon 1993 Anders 1998)

A specific list of research recommendations follows

Specific Research13 Recommendations13

bull Use replicated studies13 to establish optimum stocking13 densities13 for ponds13 and

tanks13 that can be used as13 a starting13 point for site specific refinement

bull Determine if sortinggrading13 improves13 overall growth rates13 in both ponds13 and

intensive culture facilities13

bull Investigate the use of artificial fertilizers13 to improve growth of both juvenile

and adult razorback suckers13 in ponds13

bull Determine if the razorback sucker diet gives13 better growth rates13 than cheaper

catfish or salmon feeds

bull Evaluate growth rates13 and production potential of new intensive culture

methods13 such as13 large circular tanks13

bull Evaluate13 long-shy‐term survival of fish produced from raceways13 and circular tanks13

compared to fish reared in ponds13

bull Evaluate more effective means13 of treating13 fish diseases13

bull Evaluate factors13 other than size that may increase post-shy‐stocking13 survival such

as13 exercise conditioning13 predator recognition training or rearing13 under more

natural settings13

28

13

II The Effect of Disease Treatments on Razorback Sucker

Growth

Section13 SummaryFormalin copper sulfate potassium permanganate and13 salt are all chemicals commonly13 used13 to13 treat13 Ichthyophthirius multifiliis outbreaks in captive razorback sucker (Xyrauchen13 texanus) Weexposed 190 juvenile13 razorback suckers (127 ndash 26 mm TL) to13 5 5-shy‐day treatments with13 each13 chemical to evaluate the effects13 these chemicals13 may have on growth Fish grew an average of23513 mm TL13 during the month13 study period Fish treated with formalin grew on average13 29mm TL (03 mmday) while fish treated with copper had the lowest growth averaging 20 mmTL (021 mmday) No significant differences in13 growth were observed among fish treatedwith any of the chemicals compared to untreated fish (pgt005) Reductions in growth13 as aresult of repeated chemical treatments are not likely the cause of differences in growth ratesamong13 facilities that raise razorback suckers Repeated chemical treatments may13 have otherimpacts to overall13 fitness or long-shy‐term survival but13 these effects were not13 evident13 in our study

29

13

Introduction

Preservation13 of razorback sucker13 (Xyrauchen texanus) currently13 depends on captive13

rearing and stocking programs until permanent solutions to factors that prevent wild13

recruitment are found Low survival of stocked razorback suckers (Brooks 1986 Marsh

and Brooks 198913 Marsh and Pacey13 2005) has caused target13 sizes for stocked fish to

steadily increase in efforts to reduce predation mortality (Marsh et al 2005 Schooley and

Marsh 2007) Rearing fish to larger sizes at hatcheries comes with increased costs and

creates the need to evaluate husbandry and rearing practices that may affect fish growth

Formalin copper sulfate potassium13 permanganate and salt are all chemicals

commonly used at razorback sucker rearing facilities to treat outbreaks of the protozoan

parasite13 Ichthyophthirius multifiliis ldquoIchrdquo is one of the most pathenogenic diseases of

cultured13 freshwater13 fishes (Matthews13 2005) and causes large13 losses in captive13 populations13

of endangered razorback sucker Each of these chemicals used to treat Ich only kill the free-shy‐

swimming life stage of the parasite13 requiring13 repeated doses over several13 days depending13

on water temperature These chemicals treatments are needed to prevent loss as a result

of disease outbreaks but the cumulative effects repeated disease treatments have on

growth13 are13 unknown

Copper13 sulfate13 has13 been shown to13 significantly13 reduce13 growth13 of channel catfish13 in

production13 ponds (Rabago-shy‐Castro13 2006) but it is unknown whether13 razorback suckers13

experience similar reduced growth following copper treatment Quantifying the impacts of

disease treatments on growth will help to interpret the wide differences in growth rates

observed13 at various13 razorback sucker13 production13 facilities13 throughout the13 southwest

(Ward et al 2007) If one chemical is found to have less detrimental impacts on growth

than another then it may be preferred for use as a disease treatment We evaluated growth

rates13 of razorback suckers13 under13 replicated13 and13 controlled13 conditions13 to13 assess13 effects13 of

repeated formalin copper sulfate and potassium permanganate and salt treatments on

growth13

Methods

We captured 190 juvenile razorback suckers from13 ponds at Bubbling Ponds Fish

Hatchery AZ using hoop nets or cast nets All fish were of the same age class and

30

13

averaged 179 mm total length (TL) (range13 = 127 ndash 262 mm TL)13 These fish were13 offspring13

of captive13 razorback sucker13 broodstock held13 at Dexter13 National13 Fish Hatchery13 NM13 (2007

year class) All fish were tagged with passive integrated transponder (PIT) tags and

quarantined for one month prior to the experiment to allow fish to recover from13 tagging

and become accustomed to being held in circular tanks

At the beginning of the study all fish were weighed measured and scanned for

individual tag numbers with 19 randomly selected fish placed into each13 of 10 8-shy‐foot

diameter circular tanks (Figure 2)13 Each13 tank contained13 two13 airstones13 and13 an13 individual

biofilter with a recirculating water pump (31 litersminute) that had been operating for

at least 1 month prior to the experiment to allow bacterial colonies to become

established Two tanks were designated as a control and did not receive any chemical

treatments while the other eight tanks received formalin copper sulfate potassium13

permanganate or salt treatments at two week intervals (two tanks per chemical

treatment) Formalin copper sulfate and potassium13 permanganate were treated at 1 part

per million (ppm) and salt was applied at 30 parts per thousand (ppt) These treatment

rates are commonly used to treat13 razorback13 suckers for ich at Bubbling13 Ponds Fish13

hatchery (Frank Agygos personal communication)

Figure 213 Photo ofexperimental tankswith individualbiofilters and aeration

31

13

Each treatment consisted of a series of doses applied on Wednesday Thursday and

Friday with a 90water change between each dose Biofilters were removed from13 all

tanks and held in a separate holding facility during treatments and then replaced on the

Monday following treatments after a 90water change This schedule allowed fish to be

exposed to chemical treatments for 5 consecutive days without water quality deteriorating

This 5-shy‐day chemical treatment was repeated every two weeks from13 July to October (97

days)13 for a total of 5 5-shy‐day treatments Water temperature in the treatment tanks ranged

from13 13degC (55degF) to 32degC (91degF)

Fish were fed a fixed ration of commercial razorback diet (Silvercup 4mm13 pellet)

once daily13 (2 percent body13 weight per day13 as calculated13 by13 average initial fish weight)13

At the end of the experiment all fish were again weighed measured and scanned for

individual tag numbers Growth of fish in each treatment group was compared using

analysis of variance (ANOVA) Any mortalities13 that occurred during the13 study13 were13

replaced with previously quarantined fish of equivalent size to maintain equal densities in

each13 tank13 but growth13 data was13 only13 recorded for fish which13 survived13 the13 entire13

experiment

Results

Fish at the13 start of the experiment averaged 179 mm TL (Range13 = 127 ndash 262 mm)

with no significant differences in fish length among treatment groups (F(4189) = 00183 p

gt 0999 ANOVA) On average fish grew 235 mm TL (024 mmday) during the 3 month

study13 Fish in tanks13 treated with formalin had the highest growth averaging 29 mm TL (03

mmday) while fish in tanks treated with copper had the lowest growth averaging 20 mm

TL (021 mmday) Fish in the control tanks averaged 213 mm TL in growth (022

mmday) (Figure13 3)13 Formalin-shy‐treated fish grew13 significantly faster than13 any other

treatment group but no13 significant differences in growth13 in length13 or weight were13

observed among fish treated with any of the chemicals compared to untreated (control)

fish (pgt005 ANOVA)

32

13

Figure 313 Average growthof razorback suckersexposed to a series of 5 5-shy‐day chemical treatmentsover a 97-shy‐day13 periodError bars representstandard error

Discussion13

Growth13 rates13 observed13 in our study13 (021 ndash 03 mmday) are low compared to those

reported13 in other13 studies13 of razorback sucker13 growth13 (0213 ndash 18 mmday) (Ward et al

2007) Using recirculating water systems for our study required filters to be removed and

replaced during treatments Stress to fish caused by removing and replacing filters within

the tanks as well as repeated water changes may have led to overall higher stress and

reduced growth rates compared to those reported for unconfined fish Growth in fish is

highly variable and is affected by many different physiological and environmental factors

including fish size density temperature amount of space and food (Brett 1979) We

strived to control each of these factors but other factors may have also influenced growth

in our experimental tanks During mid-shy‐summer water temperatures in the treatment

tanks reached 32degC (91degF) At these warm13 temperatures fish are very susceptible to

bacterial13 infections13 The slightly higher growth exhibited by fish in the formalin and

potassium13 permanganate treatments may have been the result of these two chemicals

33

13

being effective at controlling bacterial infections The differences in growth we measured

among treatment groups were not statistically significant and do not appear13 biologically13

meaningful during the relatively short duration of this study (97 days) although the

cumulative effects of slightly reduced growth could be biologically meaningful over longer

time frames

Reductions in growth13 as a result13 o repeated chemical treatments are not likely the

cause of differences in growth rates among facilities that raise razorback suckers

Repeated chemical treatments may have other impacts to overall fitness or long-shy‐term13

survival but these13 effects13 were13 not evident in our study It is more likely that the parasite

outbreaks themselves are the cause of different growth rates among razorback rearing

facilities rather than the chemical treatments used to treat the parasites We recommend

that hatchery managers continue to use the chemicals that are most effective at controlling

ldquoIchrdquo13 at their individual13 facilities

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower Colorado Rive Multi-shy‐species13

Conservation Plan under Work Task C10 We thank Ty Wolters and Tom13 Burke for their

support of this research and Frank Agygos and Dave Billingsly of the Bubbling Ponds Fish

Hatchery13 for their13 technical assistance13 and13 help with13 collecting13 fish

34

13

III13 Razorback Growth Rates at Bubbling Ponds ndash 2009-shy‐2011

Section13 SummaryExperimental studies at Bubbling Ponds Fish Hatchery AZ have strived to understand

factors that affect razorback sucker growth in captivity and identify ways to improve growthrates and maximize size at release Rather than performing experimental studies that wouldrequire major13 rearrangement (and likely reduced production)13 of hatchery operations our13 studies13 used normal variation in production techniques13 and practices13 to isolate factors13 thatmay modify growth rates

Our initial work identified razorback13 growth rates in13 lined ponds at standard fishdensity as 026 to13 028mmday (789 to 843 mmmonth) No significant differences in growthrate were observed among fish that had been in the pond only during the winter13 periodcompared to fish that had been in the pond the entire year indicating that water temperatures13 at Bubbling Ponds are high enough to allow fish to incorporate feed effectively year-shy‐roundHowever these growth rates are lower than most values reported from the literature fromnatural or semi-shy‐natural pond environments No significant differences in13 growth rate wereobserved13 between large and13 small fish13 within the 150 ndash 29 mm TL13 size range Additional worksuggests13 that razorback suckers13 tagged at over 300 mm TL had reduced growth rates (024mmday 73 mmmonth) as would be expected according to a typical Von13 Bertalanfy growthcurve although growth rates13 were only slightly less13 than the average growth rate for thehatchery (027513 mmday 82513 mmmonth)

Sorting13 to13 separate small fish from large fish after the first year of growth is practicedesigned13 to allow smaller fish to ldquocatch uprdquo to larger fish We found that13 this technique doesappear to13 improve growth rates of smaller fish Growth rates of sorted small razorback suckers(029 mmday 87mmmonth)13 were equal to that13 of larger13 fish (028 mmday 8413 mmmonth)indicating that sorting may have helped to offset their original slower growth trajectory

Bubbling Ponds Fish Hatchery grows razorbacks in 6 long deep ponds lined with heavyplastic 2 long deep13 earthen13 (unlined) ponds and three wide shallow earthen ponds The wideshallow ponds13 have historically produced very large fish at low density but have been found tomaintain much lower fish numbers than deeper ponds We found13 that growth13 rates ofrazorbacks kept at high density (4-shy‐700013 fish)13 in a wide shallow pond grew extremely slowly(024 mmday 726 mmmonth) This growth rate is among the slowest of any fish over theyears of our study and demonstrates that13 though the large ponds may produce large fish at lowdensity13 they are unable to overcome high13 fish13 densities

Finally one of the major factors influencing13 fish13 growth13 in hatcheries is disease onemajor summer-shy‐time disease at13 Bubbling Ponds is the ectoparasite Ich (Ichthiopthirusmultifiliis) To investigate the impact Ich has on razorback growth we eradicated fish from thespring and water conveyance ditch that supplies13 water to the hatchery using Rotenone This13 restoration effort was fairly short-shy‐lived (Ich returned to the hatchery within four months) but

35

13

growth13 rates of fish13 reared for four months without Ich present (031 mmday 92 mmmonth)were significantly higher than the following 8 months of growth for those same fish (022mmday 65 mmmonth) This disease-shy‐free growth rate is in fact faster than any13 otherprevious growth rates observed at the hatchery in our study

We conclude that growth rates at the Bubbling Ponds Fish Hatchery are likely as highas possible given the pond densities required to13 meet production goals and the Ich-shy‐infestedwater13 that feeds the facility Sorting practices are successful in helping as many fish as possiblereach stocking length as fast as possible Unlined ponds may be able to grow large fish at lowdensities but whatever factors allow for that growth13 are not able13 to overcome13 high fish densityThus the large lower ponds at Bubbling Ponds may be better utilized via renovation to13 deepenand line them

Disease is the most important factor limiting growth as may be expected to be the caseat many13 hatcheries While the spring renovation was not13 a complete success13 the dramaticreduction of fish populations in that habitat was enough to dramatically13 reduce13 the13 occurrenceof Ich at the hatchery13 Such open spring13 systems feeding a hatchery are a misfortune that canbe expected to transmit disease so we suggest that renovating the spring again to combat13 IchImproved techniques to divert water from13 the springs and more throuough treatment ofstream-shy‐side vegetation may improve the success of chemical treatment Successful renovationwould likely both improve growth rates and reduce chemical costs associated with treating Ichoutbreaks Even13 if complete renovation13 is impossible or impractical an13 effort to reduceinvasive fish density in the springs13 which act a vector for the parasite(and thereby reduce thelikelihood of13 Ich being transmitted into ponds) may still13 show dramatic improvements

36

13

Introduction

Conservation efforts13 for razorback sucker13 (Xyrauchen texanus)13 currently13 depend on

captive rearing and stocking programs Low survival of stocked razorback suckers (Brooks

1986 Marsh13 and13 Brooks13 1989 Marsh13 and13 Pacey13 2005) has13 caused13 target sizes for stocked13

fish to steadily increase in efforts to reduce predation mortality13 (Marsh13 et al13 2005

Schooley and Marsh 2007) Rearing fish to larger sizes at hatcheries comes with increased

costs and creates the need to evaluate husbandry and rearing practices that may affect fish

growth13 We evaluated growth13 rates13 of individual razorback suckers13 in ponds13 at Bubbling

Ponds Fish Hatchery13 using Passive Integrated13 Transponder (PIT) tags13 to13 obtain13 precise

growth information for individual fish so that valid comparisons of growth rates as related

to rearing practices can be made

Due to the critical nature of the razorback sucker stocking program we did not

design experimental studies that would require major rearrangement and potentially

reduce production of hatchery operations Instead our studies used normal variation in

production techniques and practices to isolate factors that may modify growth rates

Though this methodology dramatically limits replication and may limit our ability to

directly13 attribute13 differences in growth13 rates13 to13 the13 variables13 we13 investigate13 we13 were13 able13

to accomplish research goals without altering hatchery operations or impacting

production

From13 2009 through 2011 we conducted a series of observational13 growth13 studies to

determine growth rates of individual razorbacks at Bubbling Ponds The first set of

experiments included13 identifying13 growth13 rates13 in lined13 and13 unlined13 ponds determining

growth13 rates13 of fish at different13 sizes13 in13 relation13 to sorting13 practices and monitoring

razorback growth rates after removing the source of the ectoparasite13 Ich (Ichthiopthirus

multifiliis) from13 the hatchery water source13

Razorback growth rate in lined ponds

Our first growth study documented individual growth rates at normal density in 11

million gallon lined ponds13 over two13 years13 This is the standard13 grow-shy‐out process for

razorbacks13 at Bubbling Ponds We monitored growth of fish for a variety13 of sizes and13 the13

37

13

amount of time in a pond during the growing season These13 data give a snapshot of growth13

rates13 at the13 facility13 and13 provide13 the basis for comparisons throughout our study

Growth rate13 in an unlined pond

In addition13 to 6 ponds lined with heavy plastic13 sheeting13 Bubbling Ponds Fish13

Hatchery maintains two narrow and deep (same dimensions as lined ponds13 Figure13 4)13 and13

three large13 shallow unlined ponds These earthen13 ponds typically have vegetation and

associated aquatic invertebrates that may better simulate natural environments by

providing cover and improved food diversity or quality Therefore these unlined ponds

may be expected to produce higher growth rates and potentially improved survival that is

more similar to growth rates observed in more natural grow-shy‐out facilities13 Historically13 the13

large13 shallow13 ponds have produced very large fish when13 utilized at low13 fish density13 The

narrow13 deep earthen13 ponds are13 used to grow13 fry13 at high density in their first13 year of life

The major downside to unlined ponds is the difficulty in harvesting fish where a lined

pond might take 8-shy‐1013 people13 a half13 day13 to13 harvest13 lined13 ponds13 require13 intensive13 weeding13

to allow seines to be pulled and therefore require many more personnel-shy‐hours13 In addition13

to harvest challenges the shallow earthen ponds tend to suffer from13 dissolved oxygen

crashes during the summer Unlined ponds also may maintain higher13 populations13 of non-shy‐

target species such as bluegill sunfish mosquito fish and bullfrog tadpoles We measured

growth rates of suckers in a large shallow earthen pond for comparison to growth in lined

ponds13

Figure13 4 Lined13 and13 earthen ponds13 of similar dimensions (approx 1000000 gallons first

and second panels) and a large13 shallow13 earthen13 pond (third panel)

38

13

Effect of sorting on growth

Razorback13 suckers13 are13 currently13 sorted13 after their first13 year of growth13 They are13

typically removed from13 one of the13 upper earthen13 ponds and13 split into13 two13 lined13 ponds for

subsequent grow-shy‐out13 The larger13 fish (gt approximately 140 mm) are placed into one pond

and the smaller individuals in another It is possible that the larger fish were more

aggressive or adept13 at taking food so this sorting process is intended to allow smaller fish

to improve their growth rate

Effect of Ich on razorback sucker growth rates

We13 evaluated13 growth13 rates13 of razorback sucker13 in the13 presence13 and absence of the

ectoparasite13 Ich (Ichthiopthirus multifiliis) Ich outbreaks can occur in wild populations13 but

hatcheries13 have13 proven excellent locations13 for Ich because13 of very high fish densities13 which13

facilitate13 the13 transfer13 of Ich13 between13 fish This common fish parasite causes direct mortality13

to razorback13 suckers as well13 as secondary bacterial13 infections13

The open spring and13 ditch13 which13 provides water to the Bubbling13 Ponds Hatchery

has long13 been infested with mosquitofish (Gambusia affinis) that harbor13 the13 Ich parasite13

and allow13 it13 to enter the hatchery with incoming13 water13 The solution13 to13 the13 Ich problem13

was to remove the mosquitofish host using13 Rotenone Razorback13 sucker growth13 rates were13

then tracked in13 the absence of this parasite for 4 months and compared with growth rates

after Ich returned to the pond and from13 previous years

Methods

Razorback growth rate in lined ponds

On May 14 2008 141 razorback suckers were tagged with 12 mm PIT tags (1342

kHz) and placed in Pond 3 (approximately 1100000 gallons13 Figure13 4)13 at Bubbling13 Ponds

Fish Hatchery Fifty-shy‐three of these tags were recovered two months later when a large

Ichthyophthirius multifilis (Ich) outbreak killed many fish in the pond On October 15 2008

an additional13 145 PIT tagged13 fish were13 also placed into Pond13 3 On13 May13 14 2009 Pond13 3

was harvested and a total13 of 141 PIT tagged fish were recovered13 Of the tagged fish13 26 fish

had13 been13 in the13 pond since May13 of 2008 (378 days13 o growth) and 115 had been13 in13 the

39

13 40

pond since October13 15 2008 (211 days13 of growth) Numbers of fish in Pond 3 after the Ich

outbreak and for the majority of the period of growth were between 3 000 and 4000 fish

A Hobotempreg temperature13 logger13 was13 also13 installed13 in Pond 3 one meter below the water

surface13 near13 the13 outflow and13 recorded water temperature every 3 hours to allow analysis

of the effects of water temperature on growth rate (Figure13 5) This Hobotemp data is

representative of other pond temperatures throughout this study

In a second experiment 210 adult13 razorback suckers13 were13 PIT tagged13 on13 May 14

2009 and13 placed13 into13 Pond13 3 upper to13 evaluate13 growth13 rates13 of larger13 razorback suckers13 at

Bubbling13 Ponds Hatchery13 under current13 rearing13 conditions13 Size of these fish at tagging13

was (mean = 285 mm range = 205 ndash 396 mm) These fish remained in the pond for 257

days and were harvested on Jan 25 2010 to provide information on growth rates of larger

razorback suckers13 under13 current rearing conditions

Figure 513 Temperatures (degC) inrearing pond at BubblingPonds Hatchery from July toSept 2009 (top graph)13 andfrom Nov to Dec 2009 (Lowergraph) Temperaturesrecorded with a Hobotempregremote data logger13 every 3hours

13

Growth rate13 in an unlined pond

To document razorback sucker growth in earthen ponds we introduced13 225 tagged13

razorback suckers13 into13 Pond13 1 lower13 (Figure 4) in February 3 2010 Additional tagged fish

from13 other studies were added to the pond throughout the growing season and the density

of 1 lower reached a maximum13 of nearly 7000 fish in early summer 2010 Density was

reduced to approximately 6000 fish by capturing fish with hoop nets on June 3 2010 54 of

these fish were tagged fish and returned to 1 lower after being weighed and measured The

pond was harvested on January13 2713 2011 and a total13 of 254 tagged fish out13 of 4296 fish

total were removed from13 the pond The pond was harvested on January 27 2011 (358 days13

of growth) and the tagged fish were weighed and measured Total number of razorbacks in

the pond at harvest13 was 4296

Effect of sorting practices on growth rates

On March 1113 200913 Pond13 5 upper was13 harvested13 and13 split into13 two13 separate13 groups

Two hundred of the smaller fish (average size = 122 mm TL) were PIT tagged and placed

into13 Pond13 7 upper and13 200 of the13 larger13 fish (average = 160 mm TL) were PIT tagged and

placed int Pond13 8 upper Density13 in Pond13 7 was13 4500 fish and13 in Pond13 8 there13 were13 6500

fish These ponds were then harvested after 1 year and growth rates were compared to

give information on the effects of current sorting practices Hobotempreg temperature

loggers were installed in13 Ponds 7 and13 8 during13 the13 grow-shy‐out period with13 water13

temperature recorded every 2 hours13 (Figure13 6)

Effect of Ich on razorback sucker growth rates

Bubbling Ponds spring was treated with Rotenone (CFT Legumine 5) at a

concentration of 2 ppm13 to remove all mosquitofish from13 the spring The treatment

consisted of two treatments 6 hours in duration on two consecutive days (April 12 -shy‐ 13)

using13 drip13 stations13 and13 backpack sprayers13 followed13 by13 an13 additional 6 hours13 of

detoxification using sodium13 permanganate Although 12 mosquitofish were captured in the

spring pond the week following the treatments subsequent minnow trapping (20 traps

checked13 daily13 for 3 weeks) did not capture any additional fish until August 11 2010 when

41

13

juvenile mosquitofish were again detected in the spring pond Minnow traps have

subsequently been set daily with several hundred individuals removed To evaluate if Ich

was also again present in the spring we captured 15 mosquitofish from13 the spring pond on

three separate days and placed them13 in an aquaria at 25 degC with 5 longfin dace known to be

free of Ich These fish were monitored for 2 weeks with no signs of Ich developing This

indicates that even though mosquitofish have returned to the spring pond the parasite is no

longer present13 although how13 long13 this condition13 will13 persist13 is unknown13

On May 1113 201013 200 juvenile razorback13 suckers were harvested out13 of Pond 5

upper (2009 year Class from13 Dexter National Fish Hatchery) and were PIT tagged and

placed into Pond 8 to evaluate if growth rates at bubbling ponds hatchery have improved

following the renovation of the spring and the removal of the Ich parasite Unfortunately13

on Sept13 8 2010 Ich was13 again13 detected13 in Pond 8 and the pond was immediately seined

and 74 tagged fish were measured to obtain growth information for the 4-shy‐month period

during13 which13 the13 pond13 was13 Ich-shy‐free13

Figure13 6 Temperatures (degC) in rearingponds 7 and 8 at Bubbling Ponds Hatchery13 from March 2009 ndash March 201013 pond 7(top13 graph)13 and13 pond 8 (Lower13 graph)13 Temperatures recorded with a Hobotempregremote data logger every 3 hours

42

13

Results

Growth in Lined Ponds

Razorback suckers13 that had been13 in13 Pond 8 upper for the13 entire13 year13 grew an13

average of 0263 mmday (789 mmmonth) and razorback suckers that had been in the

pond for 7 months (Oct -shy‐ May) grew13 on13 average of 028 mmday (843 mmmonth) (Figure13

7) These growth13 rates13 did not significantly13 differ Fish density13 in Pond 3 during13 the13

majority of the growth period was13 00032 ndash 00036 fishgallon13 Additionally no13 significant

differences in growth rate were observed between fish smaller than 210 mm TL and fish

larger than 210 mm TL when all recaptured fish were combined

We also measured the growth rate of very large fish in a lined pond On Jan13 2513 201013

156 adult fish with PIT tags were recovered from13 Pond 3 upper13 These fish were13 in the13

pond for 257 days and experienced an average13 growth13 rate13 of 024mmday or 73

mmmonth (Figure13 7)13 This growth13 rate13 is slightly13 lower13 than13 the13 average13 growth13 rate13

observed13 at Bubbling13 Ponds Hatchery in other studies (0275 mmday 825 mmmonth)

but may not be biologically meaningful We would expect larger13 fish to13 have13 reduced

growth rates according to a typical Von Bertalanfy growth model (Bertalanffy 1957) but it

appears that13 over the size range we evaluated (300 -shy‐ 450 mm TL) growth rates have not

slowed significantly compared to that of smaller13 fish grown at Bubbling Ponds13 Hatchery

Growth13 of razorback suckers13 is known13 to13 slow as13 fish reach13 larger13 sizes but it appears13 this13

reduced growth rate may not really start to be biologically meaningful at Bubbling Ponds

Hatchery13 until razorback suckers13 exceed 450 mm TL

Growth in unlined ponds

Growth13 rates13 for the13 fish recaptured13 during13 the Pond 1 lower13 thinning13 (120 days13 in

the pond) was 024 plusmn 003 mmday (729 plusmn 090 mmmonth) (Figure13 8)13 Fish13 that were13 in

the pond for nearly the entire year grew13 an13 average13 of 024 plusmn 001 mmday (726 plusmn 027

mmmonth) These growth rates are surprisingly the lowest measured growth rates for

any part of our study and differ significantly from13 every other measured growth rate

except very large13 fish (Figure13 9)13 Separating13 out13 large fish that13 were in13 the pond for the

entire year makes no difference fish that were added to the pond at TL lt300 mm grew

43

13

Gro

wth

Rat

e (m

md

ay)

020

026

032

0244 plusmn 001 mmday (733 plusmn 028 mmmonth) and and those with TL gt= 300 mm at the

start of the experiment grew 022 plusmn 003 mmday (651 plusmn 101 mmmonth)

Razorback Growth Rates in Lined Ponds

Figure 7 Growth ofrazorback suckers in(mmday plusmn standard error)in Pond 8 upper in 2008-shy‐2009 An ANOVA did notdetect any significantdifferences

7 Months Full Year 300+ mm fish

Effects of sorting on growth

One hundred and seventy five tagged razorback suckers were recovered from13 Pond

8 upper13 on March13 24 2010 (378 days13 of growth)13 These were13 the13 larger sorted13 fish (gt140

mm TL) that came out of Pond13 5 on March13 11 2009 One13 hundred and13 twenty13 two13 tagged13

razorback suckers were also recovered from13 Pond13 7 upper on March13 31 2010 (385 days13 of

growth)13 These were13 the13 smaller sorted13 fish (lt140 mm TL) that came out of Pond13 5 on

March 1113 200913 No significant differences in growth rate (mmday) were observed among

larger fish in Pond 8 and smaller fish in Pond 7 (pgt005 ANOVA) (Figure 10)13 indicating

that13 sorting may have helped to offset the original slower growth trajectory of the smaller

fish Temperatures of Ponds 7 and 8 upper remained similar throughout the year13 (Figure

5)

44

13

13

13

Gro

wth

Rat

e (m

md

ay)

Gro

wth

Rat

e (m

md

ay)

020

026

032

020

026

032

Razorback Growth in an Unlined Pond

Figure 8 Growth of razorbacksuckers (mmday plusmn standard error) in Pond 1 lower (an unlined pond)in 2010-shy‐2011 An ANOVA did notdetect any significant differences

6 Months 12 Months lt 300 mm Fish 300+ mm Fish Growth Growth

Lined vs Earthen Ponds 1 year of growth

Figure 9 Growth of razorbacksuckers (mmday plusmn standard error) in lined and unlined ponds A t-shy‐test13 did not detect a significantdifference

Lined Pond Unlined Pond 1 Yr Growth 1 Yr Growth

45

13

Effect of Sorting G

row

th R

ate

(mm

day

) G

row

th R

ate

(mm

day

)

032

020

026

032

020

026

Smaller Fish Larger Fish

Effect of Ich

Figure 10 Average growthof razorback suckers(mmday plusmn standard error)that were size-shy‐sorted intosmall fish (pond 7) and largefish (pond 8) populations At-shy‐test did not detect asignificant difference

Figure 11 Average growth ofrazorback suckers (mmday plusmnstandard error) after Ich wasremovd from the hatcheryrsquos springand after Ich was again detected inthe pond The growth rate withoutIch is significantly higher than boththe rate after Ich and the ourstudyrsquos average annual growth ratein lined ponds (ANOVA p =00003)

Growth without Ich Growth With Ich Average Annual 4 months 4 months Growth Rate

46

13

Effect of Ich on razorback sucker growth rates

Seventy-shy‐four13 tagged13 razorback suckers13 were13 recovered from13 Pond 8 on September

15 2010 These fish had13 been13 in the pond for 4 months and experienced a growth rate of

032 mmday or 97 mmmonth (Figure13 11)13 This growth13 rate13 is significantly higher (p =

005 two sample t-shy‐test) than the mean growth rate for the same group13 of tagged fish after

Ich detection (022 mmday or 65 mmmonth) and significantly higher than any other

individual growth13 rates13 observed13 to13 date13 at Bubbling13 Ponds Hatchery13 (Figure13 11)13 If this13

growth13 rate13 were13 extended throughout13 the entire13 year13 fish on average from13 Ich-shy‐free13 ponds13

would be 16 mm longer than fish from13 ponds infested with Ich Studies conducted at

Bubbling Ponds hatchery in 2008 (Ward 2008) did not reveal any effects of the treatment

chemicals on razorback sucker growth rates so it13 is likely that13 the parasite outbreaks

themselves are causing reducing growth rates rather than the chemicals used to treat the

parasites13

Conclusions

Our results suggest that under typical hatchery operations (maximizing number of

fish produced)13 the growth13 rate13 of razorback13 suckers13 is relatively13 consistent at Bubbling13

Ponds hatchery13 at 02-shy‐03 mmday (6-shy‐9 mmmonth)13 but is lower than growth13 rates13 at

other13 facilities (02 ndash 18 mmday Ward et al 2007)13 This growth13 rate13 has13 been13 constant in

both lined and unlined ponds and at all fish densities we were able to measure To achieve13

growth13 rates13 substantially higher than this will likely require13 significant changes in rearing

practices that may not be practical in order to reach numerical production13 goals

Temperature is a key variable in fish growth but seasonal growth patterns

described13 above13 (Figure13 5) demonstrate that water temperatures are high enough in

winter to maintain razorback growth Differences in water temperature by season

currently13 do not fluctuate more than 10degC at Bubbling Ponds because of the continuous

supply of water flowing through each pond (approx 225 gallonsmin) These high water

flows appear to keep pond temperatures within the thermal preference13 for razorback

suckers13 (1213 -shy‐ 28 degC Bulkley and Pimentel 1983) throughout the entire year with

temperatures rarely dropping13 below 16deg13 C (Figures 513 6)13

47

13

Fish density is another key variable in fish growth and though the number of fish in

a pond during our study ranged from13 3000 to 700013 fish we13 did not find any13 correlation13

between13 density and growth rate13 This might yield two conclusions First13 razorback

growth13 may be changed equally13 by13 densities13 at the13 hatchery13 (ie13 a density13 of 3000 fish in a

pond is as stressful13 for razorbacks as a density13 of 7000 fish) An alternative is that other

factors13 such as disease outbreaks have13 stronger13 control over fish growth13 than13 density13

Fish density13 would13 have13 to13 be13 experimentally manipulated to test13 this13 and hatchery

operations (producing the maximum13 number of fish) prevented our manipulating density13

in ponds for this13 work The trouble with manipulating density demonstrates the difficulties

associated with changing13 hatchery13 practices experimenting with density would have

prevented BPH from13 meeting13 production13 goals Given that the stocking of smaller

razorbacks has met with very little success perhaps BPH goals could be changed from13

producing 12000 fish at 300+ mm per year to a smaller number of very large fish each

year Growing13 fewer13 larger13 fish could potentially be accomplished in the same time frame

as more smaller fish but a better understanding of how density alters growth rate would

be required to be confident13 of this

The very slow growth13 in the13 earthen13 unlined13 Pond 1 lower13 was very surprising We13

had13 anticipated13 that the13 diversified diet13 cover and13 other13 habitat features13 provided by13

unlined ponds would yield dramatically increased growth rates However these traits were

not enough to offset high fish densities and in fact the unlined pond in our study13 suffered

mortality to bring densities down to that observed normally in lined ponds

Our data13 suggest13 that razorbacks13 sucker13 growth13 rates13 are13 higher in lined13 ponds13

However we13 think the reasons13 for the13 very slow growth we observed13 in the13 unlined13 pond13

in our study13 is instead13 linked13 to13 the13 usage13 of Pond 1 lower13 during13 the13 study13 rather13 than13

intrinsic13 slow growth13 in earthen13 ponds First the pond was at extremely high density for at

least part of the study The volume of Pond 1 lower has not been estimated but hatchery

managers suggest 1500-shy‐2000 fish is an appropriate number of individuals so this pond

was at a very high density for much of the experiment Second dissolved oxygen is often

very low in the13 large13 earthen13 ponds during the heat of summer much lower than that of

lined ponds This will both limit the number of fish that can survive in the pond and almost

certainly13 increases stress13 of these13 fish potentially13 reducing growth13 The DO crashes also13

48

13

limit the amount of feed hatchery managers can give fish in these ponds sometimes for

days or weeks at a time which further reduces growth during warm13 weather

Our data13 suggests that13 growth rates at the Bubbling13 Ponds Fish Hatchery are likely

as high as possible given13 the pond densities required to meet production goals and the Ich-shy‐

infested water that feeds the facility Sorting practices are successful in helping as many

fish as possible reach stocking length as fast as possible Unlined ponds may be able to

grow13 large13 fish at low13 densities13 but whatever factors allow13 for that13 growth are not13 able to

overcome high fish density The removal of invasive13 fis that act as13 a host for the13 parasite13

Ich fish from13 the Bubbling13 Ponds spring13 allowed the highest13 growth rate at 032 mmday13

(96 mmmonth) but that growth rate decreased again as Ich re-shy‐infested13 the13 hatchery13

Consistently13 achieving13 growth13 rates13 as high or substantially13 higher than13 this13 will likely13

require13 significant changes in rearing practices that may not be practical in order to13 reach13

numerical production13 goals

Two major changes that might result in higher growth rates are substantially

reducing fish density and modifying the way spring water is delivered to the facility (via

either repeated chemical treatments or enclosed concrete water diversions) to eliminate

Ich from13 the hatchery source water Other potential changes not address by our work

include13 flow-shy‐training razorbacks much previous literature including MSCP-shy‐funded13 work

on razorback suckers13 suggests13 that fish growing13 in flowing water will grow13 faster than fish

in still water (Jorgensen and Jobling 1994) Furthermore there are a wide variety of

potential benefits associated with growing13 fish13 in flowing13 water in addition13 to increased

growth13 rates13 (Davidson13 199713 Castro13 et al13 2011) Another option13 for increasing13 growth13

rates13 include13 changing to13 intensive13 culture13 in large circular13 tanks

Finally given that the stocking of smaller razorbacks has met with very little

success13 perhaps13 BPH13 goals13 could13 be13 changed from13 producing 12000 fish at 300+ mm per

year to a smaller number of very large fish each year Growing fewer larger fish could

potentially be accomplished in the same time frame as more smaller fish but a better

understanding13 of how density13 alters growth13 rate13 would13 be13 required to13 be13 confident of this

49

13

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower13 Colorado13 River Multi-shy‐Species13

Conservation Program13 (LCRMSCP) under Work Task C10 We13 thank Ty Wolters13 Tom13

Burke13 and Eric13 Volkman for their support of this research and Frank Agygos and Dave

Billingsly13 of the Bubbling13 Ponds Fish Hatchery13 for their willingness to participate in13 this

research13 and13 for their technical assistance We also thank the LCRMSCP fish group from13

Boulder City13 NV for their assistance with harvesting13 ponds and tagging13 fish13

50

13

Literature13 CitedAnders P J 1998 Conservation aquaculture and endangered species can objective science13

prevail13 over risk13 anxiety Fisheries 23(11) 28-shy‐31

Anderson R O and R M Nuemann 1996 Length weight and associated structural indicesPages 447 ndash 482 in B R Murphy13 and D13 W Willis13 editors13 Fisheries techniques13 2ndedtion American Fisheries13 Society13 Bethesda13 Maryland

Bain M B J T Finn and H E Brooks 1988 Streamflow regulation and fish communitystructure13 Ecology13 69382-shy‐392

Bays J H Zarbock R Whitman and T Murphy 2005 Conceptual design and managementof native13 fish refugia on the13 lower13 Colorado13 River In13 CL Spring13 and13 S Leoneditors Proceedings of two symposia Restoring native fish to the lower ColoradoRiver13 interactions13 of native and non-shy‐native13 fishes 13ndash1413 July13 1999 Las13 Vegas13 Nevada13 Restoring13 natural function within a modified riverine environment thelower Colorado River13 8ndash913 July13 1998 U S Fish and13 Wildlife13 Service Southwestern13 Region Albuquerque New Mexico Pages 167-shy‐177

Bertalanffy L Von 1957 Quantitative laws in metabolism13 and growth13 Q Rev Biology 32217 ndash 231

Bingham T B Scheer and C McAda 2003 Propagation facilities in Grand Valley (24 RoadHatchery Horsethief13 Ponds and13 grow-shy‐out ponds) for captive13 rearing13 ofendangered13 fishes for the13 upper13 Colorado13 River basin13 Colorado River RecoveryProgram FY2003 annual project report13 US Fish and13 Wildlife13 Service GrandJunction13 4pp

Birchell G J and K Christopherson 2004 Survival growth and recruitment of larval andjuvenile razorback13 sucker (Xyrauchen texanus) introduced13 into13 floodplain13 depressions13 of the13 Green River Utah13 Final report13 Upper13 Colorado13 RiverEndangered Fish Recovery Program13 Project No C-shy‐6RZ Publication Number 04-shy‐1513 Utah13 Division of Wildlife13 Resources Salt Lake13 City13 Utah13 67 pages

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Brett J R 1979 Environmental Factors and growth pages 599-shy‐67513 InW S Hoar13 D13 J13 Randall and J R Brett (eds) Fish Physiology Volume 8 Bioenergetics and GrowthAcademic Press New York

Brooks J E 1986 Annual reintroduction and monitoring report for razorback suckerXyrauchen texanus in the Gila River Basin Arizona 1985 US Fish and WildlifeService13 Offices of Endangered13 Species and Fishery13 Resources Albuquerque 23 pp

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Brunson13 R E and K D13 Christopherson13 200513 Larval13 razorback13 sucker and bonytailsurvival and13 growth13 in the13 presence13 of nonnative13 fish in the13 Baeser13 floodplainwetland of the middle Green River Final report prepared for Upper13 Colorado RiverBasin Endangered Fish Recovery Program Project No C-shy‐6-shy‐rz-shy‐bt Publication13 No 05-shy‐26 Utah13 Division of Wildlife13 Resources13 Vernal13 32 pp

Bulkley R V and R Pimentel 1983 Temperature preference and avoidance by adultrazorback suckers Transactions of the American Fisheries Society 112601-shy‐607

Burke13 T13 199513 Rearing13 wild razorback13 sucker larvae in13 lake-shy‐side13 backwaters13 LakeMohave ArizonaNevada Proceedings of the Desert Fishes Council 2635

Busacker G P I R Adelman and E M Goolish13 199013 Growth13 Pages 363 ndash 387 in C BSchreck and p B Moyle editors Methods for fish biology American FisheriesSociety Bethesda Maryland

Castro V B Grisdale-shy‐Helland S J Helland T Kristensen S M Jorgensen J Helgrud13 GClaireaux A P Farrell A Krasnov and H Takle 2011 Aerobic training stimulatesgrowth and promotes disease resistance in Atlantic salmon (Salmo salar)Comparative Biochemistry and Physiology -shy‐ Part A Molecular amp IntegrativePhysiology13 160(2) 278-shy‐290

Czapla T E 2002 Facilities plan for the production of endangered fishes to meet statestocking13 plans13 as13 part of the13 Upper13 Colorado13 River Endangered13 Fish RecoveryProgram Upper Colorado River Basin Recovery Implementation Program US Fishand Wildlife Service13 Denver13 9 pp

Davidson W 1997 The effects13 of exercise13 training on teleost fish a review of recentliterature Comput Biochem Physiol 117A67ndash75

Figiel Jr C R 2005 Annual report fiscal year 2004 Willow Beach National13 Fish HatcheryUS Fish and Wildlife13 Service Willow Beach 17 pp

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Kaeding L R and D B Osmundson 198913 Colorado13 Squawfish13 and13 razorback sucker grow-shy‐out pond studies as part of conservation measures for the green mountain andRuedi reservoir water sales Final report for agreement number 6-shy‐AA-shy‐60-shy‐00150

Koebele13 B P13 198513 Growth and the size hierarchy effect an experimental assessment ofthree proposed mechanisms activity differences disproportional food acquisition13 pysiological stress Environmental Biology of Fishes 12 181-shy‐188

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Marsh13 P13 C13 1987a13 Digestive tract13 contents13 of adult razorback suckers13 in Lake13 MohaveArizona-shy‐Nevada Transactions of the American Fisheries Society 116117-shy‐119

Marsh P C 1987b Native fishes at Buenos Aires National Wildlife Refuge and ArizonaState University Research Park Arizona opportunities for management researchand public13 education13 on13 endangered species13 Proceedings of the Desert13 FishesCouncil 1967-shy‐78

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Nesler T P K Christopherson J M Hudson C W McAda F Pfeifer and T E Czapla 2003An integrated stocking plan for razorback sucker bonytail and Colorado13 pikeminnow for the Upper Colorado River Endangered Fish Recovery ProgramAddendum13 to State Stocking Plans Upper Colorado River Basin Recovery13 Implementation Program 12 pp

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13

endangered13 fishes for the13 Upper Colorado13 River Basin13 Colorado13 River Recovery13 Program FY 99 annual project report Project No 29a13 US Fish and Wildlife Service13 Grand13 Junction13 5pp

Pfeifer F S Seversen and M Montagne 2003 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2003 annual reportProject No 29b13 US Fish and Wildlife13 Service Vernal13 4pp

Rabago-shy‐Castro J L Sanchez13 J G Perez-shy‐Castaneda R and13 Gonzalez-shy‐Gonzlez A 2006Effects of the prophylactic use of Romet-shy‐3013 and13 copper13 sulfate13 on growth13 condition13 and feeding13 indicies in13 channel13 catfish (Ictalurus punctatus) Aquaculture 253 343-shy‐349

Reinitz GL L E Orme and F N Hitzel 1979 Variations of body compositio and growth13 among strains of rainbow trout Transactions of the American Fisheries Society 108204-shy‐207

Ruppert13 J13 B P B Holden13 and P D Abate 1999 Age estimation and growth of razorbacksucker13 Xyrauchen texanus in Lake13 Mead Nevada Proceedings13 of the Desert FishesCouncil 3040

Schnoor K D and J Logan 2002 Operation and maintenance of JW Mumma nativeaquatic13 species restoration facility Colorado Colorado River Recovery Program FY2002 annual project report13 Project No 29d Colorado13 Division of Wildlife Alamosa3pp

Salisbury13 L13 1998 Factors13 affecting razorback13 sucker growth13 in Lake13 Mohave backwaters13 MS Thesis13 Unviersity13 of Nevada13 Las13 Vegas

Schooley J13 D13 and P C13 Marsh13 2007 Stocking of endangerdd13 razorback13 suckers13 in thelower Colorado River Basin13 over three decades 1974-shy‐2004 North American Journalof Fisheries Management 27 43-shy‐51

Severson S H H M Tyus and G B Haines 1992 An evaluation of feeds for raisingrazorback sucker Xyrauchen texanus Journal of Applied Aquaculture 155-shy‐65

Toney D P 1974 Observations13 on the13 propagation13 and13 rearing13 of two13 endangered species13 in a hatchery environment Proceedings of the Annual Conference of the Western13 Association of State Game and Fish Commissions 54 252-shy‐259

Tyus H M13 1998 Razorback sucker13 (Xyrauchen texanus) recovery plan13 University13 ofColorado Center for Limnology Boulder13 76 pages

Tyus H M13 and13 S H Severson 1990 Growth13 and13 survival of larval razorback suckers fedfive formulated diets The Progressive Fish Culturist 52197-shy‐200

56

13

Ulibarri M E 2003 Annual report fiscal year 2001 Dexter National Fish Hatchery13 andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 26 pages

Ulibarri M E 2003 Annual report fiscal year 2002 Dexter National Fish Hatchery andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 59 pages

USBR 2006 Lower13 Colorado13 River Multi-shy‐Species Conservation Program final fishaugmentation plan Boulder City 19 pp

USFWS 2002 Razorback sucker (Xyraouchen texanus) recovery goals Amendment andsupplement to the Razorback Sucker Recovery Plan13 US Fish and Wildlife Service13 Region 6 Denver13 Colorado

USFWS 1999 Annual report 1999 Ouray National Fish Hatchery Vernal 25pp

USFWS 2004 Management plan for the big-shy‐river13 fishes of the13 lower13 Colorado13 river basinamendment and supplement to the bonytail humpback chub Coloradopikeminnow and razorback sucker recovery plans

USFWS13 2005 Station13 profile13 of the13 Dexter13 National Fish Hatchery13 and Technology CenterUS Fish and Wildlife13 Service Dexter

Valdez R A P G Mangan R Smith and B Nilson 1982 Upper Colorado River fisheriesinvestigations13 inW H Miller J J Valentine D L Archer H M Tyus R A Valdezand L13 Kaeding13 editors13 Colorado River Fishery13 Project13 Part 2 Field13 investigations13 US Bureau of Reclamation Salt Lake City Utah

WBNFH 2004 Culture methods of the endangered razorback sucker Xyrauchen texanusUS Fish and Wildlife13 Service Willow Beach National Fish Hatchery13 8 pp

Ward D 2008 Effects of disease treatments on growth of razorback sucker ReportSubmitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 Inpartial fulfillment of work task C10 agreement number 06FG30039

Ward13 D13 M Childs and W Persons 2007 Factors13 affecting13 growth13 of razorback sucker13 (Xyrauchen texanus) in captivity Literature review and knowledge assessmentReport Submitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 In partial fulfillment of work task C10 agreement number 06FG30039

57

Appendices

Appendix 1 Survey Questions Survey of Razorback Sucker Culture in the

Southwestern United States

The enclosed survey is being distributed by the Arizona Game and Fish Department to razorback sucker culture facilities throughout

the Southwestern United States The purpose of this survey is to consolidate information regarding culture of this species so that

appropriate facility improvements can be considered for Bubbling Ponds Hatchery in Arizona Specifically we wish to increase

growth rate and production efficiency at the hatchery Information gathered in this survey will be summarized in a final report to US

Bureau of Reclamation in Boulder City NV and disseminated to all facilities that participate in the survey A workshop to discuss

the findings of this study as well as to share general information concerning razorback sucker culture will be organized by the

Arizona Game and Fish Department at the conclusion of this study and all participants will be invited

Thank you for taking the time to fill out this survey Please contact Mike Childs if you have questions or would like to discuss the

survey

Mike Childs

mchildssedonanet

(928) 639-1346

(928) 634-1279

Facility_____________________________________ Date___________________

Contact Phone _____________________________

ContactPerson_______________________________

Contact Email _______________________________

1 Water quality ranges at this culture facility

Season

Spring (Mar-May) Summer (Jun-Aug) Fall (Sept-Nov) Winter (Dec-Feb)

Temperature (C)

PH

DO (mgL)

PO4 (mgL)

TDS (mgL)

Hardness (mgL)

CaCO3

Pathogens

37

13

One of the main strategies for maintaining genetic refugia and self-shy‐sustaining13

populations of razorback13 sucker in the lower Colorado13 River basin13 is to rear razorback13

sucker13 larvae13 in production13 ponds until they13 are13 a suitable13 size for stocking13 (USFWS13 2004)

Pond culture has proven useful to promote rapid growth of juvenile razorback suckers

(Kaeding and Osmundson 1989) Marsh (1994) reported that growth rates of razorback

suckers13 reared13 in golf-shy‐course13 ponds exceeded13 the13 best growth13 rates13 obtained13 under

intensive13 culture13 conditions13 at federal hatcheries13 especially13 during the13 first several years13

of life Growth rates in these semi-shy‐natural ponds are also comparable to estimated growth

rates13 of juvenile13 wild13 fish (McCarthy13 and13 Minckley13 1987) Modde13 and13 Haines13 (2005)

reported13 the13 greatest growth13 rates13 in the13 largest and13 deepest floodplains13 with13 the13 greatest

amount of submergent vegetation but excellent growth and survival of fish in a grow-shy‐out

pond is of little value if there is not an efficient way to collect the fish from13 the pond

(Kaeding and Osmundson 1989)

Temperature13

Bulkley and Pimentel (1983) used shuttle boxes in the laboratory to determine a

temperature preference13 for razorback suckers13 of 23-shy‐24degC13 In13 their13 studies13 razorback

suckers were found to avoid temperatures below 118 degC or above 286 degC Razorback

suckers at Bubbling Ponds Hatchery are more active in the spring and feed better as

photoperiod increases even prior to water temperatures rising (Frank Agygos personal

communication) Table 3 briefly summarizes water temperature data from13 each facility

Detailed seasonal water temperature profiles are not currently available for many

razorback grow-shy‐out sites13

Density13

Extensive studies have been conducted on commercially important species to

evaluate stocking densities and feeding rates that maximize production For these species

controlled experiments under laboratory conditions have established relationships

between temperature density and feed ration on growth (Brett 1979) but this information

is sporadic13 or non-shy‐existent for razorback suckers13 (Bays13 et al13 2005) Fish culturists13 with13

24

13

experience13 rearing13 razorback suckers13 typically13 have13 target stocking13 densities13 that13 they use

(Tables13 4 -shy‐ 5) These stocking densities have largely been determined over time by trial

and error These approximate stocking densities provide a good starting point for more

controlled13 types13 of replicated13 pond studies13

Feed ration

Razorback13 suckers are currently13 being13 fed a wide variety13 of prepared diets (Table 7)

that range from13 a slow-shy‐sinking salmon feed manufactured by Silver Cupreg to a spirulina

and krill-shy‐enhanced catfish feed made by Rangenreg Most locations are feeding 20 ndash 50

body13 weight per13 day13 Methods13 for culture13 of razorback sucker13 larvae13 in intensive13 settings13 at

fish hatcheries are well documented (Figiel 2005) and various larval fish diets have been

evaluated13 (Tyus and13 Severson 1990 Severson et al13 1992) but no standardized13 procedures

are used for feeding13 larval13 fish in13 intensive settings13

Razorback sucker larvae are also effectively reared in pond environments using

natural foods supplemented with larval fish diets and survival is high when no predators

are present13 (Mueller 2006)13 Growth rates for larval13 and early juvenile razorback13 suckers

may increase with pond fertilization Diet and physiological studies on wild razorback

suckers indicate that they feed on plankton as well as benthic organisms during their entire

life (Marsh 1987) Artificially fertilizing ponds may greatly increase production capacity

and growth rates for razorback13 sucker (Papoulias and Minckley13 1992) and warrants

further13 investigation13

Handling stress

Handling stress13 has13 been shown to13 influence growth13 rates13 Paukert13 et al (2005)

found that growth of bonytail chub was reduced by 26when compared with controls

after being13 repeatedly13 captured and handled in13 hoop13 nets13 Handling13 effects are likely13 to be

similar for razorback suckers that are repeatedly13 captured and sorted in13 a hatchery13 setting13

Razorback suckers that are handled at Willow Beach National Fish Hatchery will commonly

not eat for two weeks after handling (John Scott personal communication) This creates a

difficult situation13 for production13 facilities because13 fish13 need to be sorted to ensure13 large13

25

13

aggressive fish do not interfere with growth of smaller individuals but frequent handling

and sorting13 causes stress related reductions in13 growth13

Measuring Growth in Captive Fish

Weight is the traditional measure used to estimate growth or production in

aquaculture settings13 Groups of fish are typically13 weighed and an average individual13 weight13

is computed (Busacker et al 1990) Although this method is often logistically the easiest it

may not be the most informative for species with highly variable growth rates like

razorback suckers especially when target lengths must be reached before fish can be

stocked Weight can also be highly influenced by things like stomach fullness or

development of gonads (Busacker et al 1990) Condition factor or relative weight can also

be used to assess growth of fish but these tools may be more robust predictors of fecundity

than of growth (Anderson and Neuman 1996) For some species sexes need to be

distinguished because males and females may differ in morphology (Anderson and

Neumann 1996) Mueller (2006) analyzed growth rates based on PIT tag recaptures of 86

razorback suckers13 in High13 Levee Pond13 and13 found13 that differences13 in growth13 do not appear13

to occur until fish are over 450 mm TL at which time growth rate in males slows while

females continue to grow at a slightly higher rate This would indicate that sex may not be

an important factor to consider when examining growth rates unless the target grow-shy‐out

size is above 450 mm TL

The best measures of growth are often determined from13 the length and weight of

individuals rather than from13 groups of fish (Anderson and Nuemannn 1996) because

individual growth rates give better estimates of confidence and variance (Busacker et13 al

1990) Length frequency analysis or recapture of previously marked individuals of a known

size is likely to yield the most useful information for razorback sucker growth The success

of any of these methods depends on proper sampling procedures that are representative of

the population as a whole (Busacker et al 1990) Sampling methods that are known to be

size-shy‐biased such as trammel nets (Mueller et al 2004) or cast nets should not be used when

trying to measure growth rates13

26

13

Conclusions

For razorback sucker survival is largely associated with stocking size Additional

focused13 research13 is therefore13 needed to13 identify13 ways13 to13 increase13 growth13 rates13 of captive-shy‐

reared13 razorback sucker Growth13 rate13 in fish is controlled13 by many factors including fish

size and age temperature density and feed ration which can all be highly correlated

Growth of razorback suckers is also inherently variable which makes the task of identifying

the key factors that13 affect13 growth in13 captivity even more difficult The focus at most

razorback rearing facilities13 is production so the13 types13 of data that are13 collected13 are13 often

insufficient for detailed13 evaluations13 of individual rearing13 practices13 on growth13 Surveys of

existing13 razorback sucker13 rearing facilities indicate that culture methods vary widely and

the types of growth data13 that13 are collected are not13 standardized13 Replicated studies with

detailed information on rearing location water temperature initial stocking size stocking

density and the sizes of all fish at harvest are needed in order to compare the effects of

individual rearing practices on growth This type of research will ultimately provide both

time and cost-shy‐savings to production facilities by reducing the amount of time necessary13 for

razorback sucker to reach stocking size improving overall production efficiency

Optimum13 rearing densities for razorback sucker larvae and juveniles remain to be

determined Current stocking densities will be very useful as starting point for more

detailed studies and although optimum13 rearing densities are likely to be site-shy‐specific13

replicated studies on density will provide a valuable reference for hatchery managers

Frequency13 of sorting is another13 area that needs13 further13 research Frequent

handling13 and13 sorting13 can13 cause13 stress-shy‐related13 reductions13 in growth but not sorting can

create dominance hierarchies that further reduce growth rates of subordinate individuals

The effects13 of sorting13 on overall fish growth13 in both13 pond and13 intensive13 culture13

environments warrant further investigation Research techniques for these types of

experiments are well understood and typically utilize a matrix of replicate ponds per

variable (Bays et al 2005) In every case accurate and complete records of sampling

procedures and data collection are needed in order to interpret data and make inferences

about13 growth rates (Busacker et13 al 1990)13

27

13

Additional research is also needed to evaluate long-shy‐term13 survival of stocked fish

reared in ponds compared to fish13 reared13 in intensive13 culture13 facilities13 Exercise13

conditioning13 and predator-shy‐recognition training may also increase survival of stocked fish

and be more economically feasible than rearing fish to increasingly larger sizes prior to

stocking13 The success13 of traditional fish hatchery programs is measured largely by the

number of fish stocked but hatchery programs for endangered species must measure

success in terms of long-shy‐term13 survival and species recovery (Brannon 1993 Anders 1998)

A specific list of research recommendations follows

Specific Research13 Recommendations13

bull Use replicated studies13 to establish optimum stocking13 densities13 for ponds13 and

tanks13 that can be used as13 a starting13 point for site specific refinement

bull Determine if sortinggrading13 improves13 overall growth rates13 in both ponds13 and

intensive culture facilities13

bull Investigate the use of artificial fertilizers13 to improve growth of both juvenile

and adult razorback suckers13 in ponds13

bull Determine if the razorback sucker diet gives13 better growth rates13 than cheaper

catfish or salmon feeds

bull Evaluate growth rates13 and production potential of new intensive culture

methods13 such as13 large circular tanks13

bull Evaluate13 long-shy‐term survival of fish produced from raceways13 and circular tanks13

compared to fish reared in ponds13

bull Evaluate more effective means13 of treating13 fish diseases13

bull Evaluate factors13 other than size that may increase post-shy‐stocking13 survival such

as13 exercise conditioning13 predator recognition training or rearing13 under more

natural settings13

28

13

II The Effect of Disease Treatments on Razorback Sucker

Growth

Section13 SummaryFormalin copper sulfate potassium permanganate and13 salt are all chemicals commonly13 used13 to13 treat13 Ichthyophthirius multifiliis outbreaks in captive razorback sucker (Xyrauchen13 texanus) Weexposed 190 juvenile13 razorback suckers (127 ndash 26 mm TL) to13 5 5-shy‐day treatments with13 each13 chemical to evaluate the effects13 these chemicals13 may have on growth Fish grew an average of23513 mm TL13 during the month13 study period Fish treated with formalin grew on average13 29mm TL (03 mmday) while fish treated with copper had the lowest growth averaging 20 mmTL (021 mmday) No significant differences in13 growth were observed among fish treatedwith any of the chemicals compared to untreated fish (pgt005) Reductions in growth13 as aresult of repeated chemical treatments are not likely the cause of differences in growth ratesamong13 facilities that raise razorback suckers Repeated chemical treatments may13 have otherimpacts to overall13 fitness or long-shy‐term survival but13 these effects were not13 evident13 in our study

29

13

Introduction

Preservation13 of razorback sucker13 (Xyrauchen texanus) currently13 depends on captive13

rearing and stocking programs until permanent solutions to factors that prevent wild13

recruitment are found Low survival of stocked razorback suckers (Brooks 1986 Marsh

and Brooks 198913 Marsh and Pacey13 2005) has caused target13 sizes for stocked fish to

steadily increase in efforts to reduce predation mortality (Marsh et al 2005 Schooley and

Marsh 2007) Rearing fish to larger sizes at hatcheries comes with increased costs and

creates the need to evaluate husbandry and rearing practices that may affect fish growth

Formalin copper sulfate potassium13 permanganate and salt are all chemicals

commonly used at razorback sucker rearing facilities to treat outbreaks of the protozoan

parasite13 Ichthyophthirius multifiliis ldquoIchrdquo is one of the most pathenogenic diseases of

cultured13 freshwater13 fishes (Matthews13 2005) and causes large13 losses in captive13 populations13

of endangered razorback sucker Each of these chemicals used to treat Ich only kill the free-shy‐

swimming life stage of the parasite13 requiring13 repeated doses over several13 days depending13

on water temperature These chemicals treatments are needed to prevent loss as a result

of disease outbreaks but the cumulative effects repeated disease treatments have on

growth13 are13 unknown

Copper13 sulfate13 has13 been shown to13 significantly13 reduce13 growth13 of channel catfish13 in

production13 ponds (Rabago-shy‐Castro13 2006) but it is unknown whether13 razorback suckers13

experience similar reduced growth following copper treatment Quantifying the impacts of

disease treatments on growth will help to interpret the wide differences in growth rates

observed13 at various13 razorback sucker13 production13 facilities13 throughout the13 southwest

(Ward et al 2007) If one chemical is found to have less detrimental impacts on growth

than another then it may be preferred for use as a disease treatment We evaluated growth

rates13 of razorback suckers13 under13 replicated13 and13 controlled13 conditions13 to13 assess13 effects13 of

repeated formalin copper sulfate and potassium permanganate and salt treatments on

growth13

Methods

We captured 190 juvenile razorback suckers from13 ponds at Bubbling Ponds Fish

Hatchery AZ using hoop nets or cast nets All fish were of the same age class and

30

13

averaged 179 mm total length (TL) (range13 = 127 ndash 262 mm TL)13 These fish were13 offspring13

of captive13 razorback sucker13 broodstock held13 at Dexter13 National13 Fish Hatchery13 NM13 (2007

year class) All fish were tagged with passive integrated transponder (PIT) tags and

quarantined for one month prior to the experiment to allow fish to recover from13 tagging

and become accustomed to being held in circular tanks

At the beginning of the study all fish were weighed measured and scanned for

individual tag numbers with 19 randomly selected fish placed into each13 of 10 8-shy‐foot

diameter circular tanks (Figure 2)13 Each13 tank contained13 two13 airstones13 and13 an13 individual

biofilter with a recirculating water pump (31 litersminute) that had been operating for

at least 1 month prior to the experiment to allow bacterial colonies to become

established Two tanks were designated as a control and did not receive any chemical

treatments while the other eight tanks received formalin copper sulfate potassium13

permanganate or salt treatments at two week intervals (two tanks per chemical

treatment) Formalin copper sulfate and potassium13 permanganate were treated at 1 part

per million (ppm) and salt was applied at 30 parts per thousand (ppt) These treatment

rates are commonly used to treat13 razorback13 suckers for ich at Bubbling13 Ponds Fish13

hatchery (Frank Agygos personal communication)

Figure 213 Photo ofexperimental tankswith individualbiofilters and aeration

31

13

Each treatment consisted of a series of doses applied on Wednesday Thursday and

Friday with a 90water change between each dose Biofilters were removed from13 all

tanks and held in a separate holding facility during treatments and then replaced on the

Monday following treatments after a 90water change This schedule allowed fish to be

exposed to chemical treatments for 5 consecutive days without water quality deteriorating

This 5-shy‐day chemical treatment was repeated every two weeks from13 July to October (97

days)13 for a total of 5 5-shy‐day treatments Water temperature in the treatment tanks ranged

from13 13degC (55degF) to 32degC (91degF)

Fish were fed a fixed ration of commercial razorback diet (Silvercup 4mm13 pellet)

once daily13 (2 percent body13 weight per day13 as calculated13 by13 average initial fish weight)13

At the end of the experiment all fish were again weighed measured and scanned for

individual tag numbers Growth of fish in each treatment group was compared using

analysis of variance (ANOVA) Any mortalities13 that occurred during the13 study13 were13

replaced with previously quarantined fish of equivalent size to maintain equal densities in

each13 tank13 but growth13 data was13 only13 recorded for fish which13 survived13 the13 entire13

experiment

Results

Fish at the13 start of the experiment averaged 179 mm TL (Range13 = 127 ndash 262 mm)

with no significant differences in fish length among treatment groups (F(4189) = 00183 p

gt 0999 ANOVA) On average fish grew 235 mm TL (024 mmday) during the 3 month

study13 Fish in tanks13 treated with formalin had the highest growth averaging 29 mm TL (03

mmday) while fish in tanks treated with copper had the lowest growth averaging 20 mm

TL (021 mmday) Fish in the control tanks averaged 213 mm TL in growth (022

mmday) (Figure13 3)13 Formalin-shy‐treated fish grew13 significantly faster than13 any other

treatment group but no13 significant differences in growth13 in length13 or weight were13

observed among fish treated with any of the chemicals compared to untreated (control)

fish (pgt005 ANOVA)

32

13

Figure 313 Average growthof razorback suckersexposed to a series of 5 5-shy‐day chemical treatmentsover a 97-shy‐day13 periodError bars representstandard error

Discussion13

Growth13 rates13 observed13 in our study13 (021 ndash 03 mmday) are low compared to those

reported13 in other13 studies13 of razorback sucker13 growth13 (0213 ndash 18 mmday) (Ward et al

2007) Using recirculating water systems for our study required filters to be removed and

replaced during treatments Stress to fish caused by removing and replacing filters within

the tanks as well as repeated water changes may have led to overall higher stress and

reduced growth rates compared to those reported for unconfined fish Growth in fish is

highly variable and is affected by many different physiological and environmental factors

including fish size density temperature amount of space and food (Brett 1979) We

strived to control each of these factors but other factors may have also influenced growth

in our experimental tanks During mid-shy‐summer water temperatures in the treatment

tanks reached 32degC (91degF) At these warm13 temperatures fish are very susceptible to

bacterial13 infections13 The slightly higher growth exhibited by fish in the formalin and

potassium13 permanganate treatments may have been the result of these two chemicals

33

13

being effective at controlling bacterial infections The differences in growth we measured

among treatment groups were not statistically significant and do not appear13 biologically13

meaningful during the relatively short duration of this study (97 days) although the

cumulative effects of slightly reduced growth could be biologically meaningful over longer

time frames

Reductions in growth13 as a result13 o repeated chemical treatments are not likely the

cause of differences in growth rates among facilities that raise razorback suckers

Repeated chemical treatments may have other impacts to overall fitness or long-shy‐term13

survival but these13 effects13 were13 not evident in our study It is more likely that the parasite

outbreaks themselves are the cause of different growth rates among razorback rearing

facilities rather than the chemical treatments used to treat the parasites We recommend

that hatchery managers continue to use the chemicals that are most effective at controlling

ldquoIchrdquo13 at their individual13 facilities

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower Colorado Rive Multi-shy‐species13

Conservation Plan under Work Task C10 We thank Ty Wolters and Tom13 Burke for their

support of this research and Frank Agygos and Dave Billingsly of the Bubbling Ponds Fish

Hatchery13 for their13 technical assistance13 and13 help with13 collecting13 fish

34

13

III13 Razorback Growth Rates at Bubbling Ponds ndash 2009-shy‐2011

Section13 SummaryExperimental studies at Bubbling Ponds Fish Hatchery AZ have strived to understand

factors that affect razorback sucker growth in captivity and identify ways to improve growthrates and maximize size at release Rather than performing experimental studies that wouldrequire major13 rearrangement (and likely reduced production)13 of hatchery operations our13 studies13 used normal variation in production techniques13 and practices13 to isolate factors13 thatmay modify growth rates

Our initial work identified razorback13 growth rates in13 lined ponds at standard fishdensity as 026 to13 028mmday (789 to 843 mmmonth) No significant differences in growthrate were observed among fish that had been in the pond only during the winter13 periodcompared to fish that had been in the pond the entire year indicating that water temperatures13 at Bubbling Ponds are high enough to allow fish to incorporate feed effectively year-shy‐roundHowever these growth rates are lower than most values reported from the literature fromnatural or semi-shy‐natural pond environments No significant differences in13 growth rate wereobserved13 between large and13 small fish13 within the 150 ndash 29 mm TL13 size range Additional worksuggests13 that razorback suckers13 tagged at over 300 mm TL had reduced growth rates (024mmday 73 mmmonth) as would be expected according to a typical Von13 Bertalanfy growthcurve although growth rates13 were only slightly less13 than the average growth rate for thehatchery (027513 mmday 82513 mmmonth)

Sorting13 to13 separate small fish from large fish after the first year of growth is practicedesigned13 to allow smaller fish to ldquocatch uprdquo to larger fish We found that13 this technique doesappear to13 improve growth rates of smaller fish Growth rates of sorted small razorback suckers(029 mmday 87mmmonth)13 were equal to that13 of larger13 fish (028 mmday 8413 mmmonth)indicating that sorting may have helped to offset their original slower growth trajectory

Bubbling Ponds Fish Hatchery grows razorbacks in 6 long deep ponds lined with heavyplastic 2 long deep13 earthen13 (unlined) ponds and three wide shallow earthen ponds The wideshallow ponds13 have historically produced very large fish at low density but have been found tomaintain much lower fish numbers than deeper ponds We found13 that growth13 rates ofrazorbacks kept at high density (4-shy‐700013 fish)13 in a wide shallow pond grew extremely slowly(024 mmday 726 mmmonth) This growth rate is among the slowest of any fish over theyears of our study and demonstrates that13 though the large ponds may produce large fish at lowdensity13 they are unable to overcome high13 fish13 densities

Finally one of the major factors influencing13 fish13 growth13 in hatcheries is disease onemajor summer-shy‐time disease at13 Bubbling Ponds is the ectoparasite Ich (Ichthiopthirusmultifiliis) To investigate the impact Ich has on razorback growth we eradicated fish from thespring and water conveyance ditch that supplies13 water to the hatchery using Rotenone This13 restoration effort was fairly short-shy‐lived (Ich returned to the hatchery within four months) but

35

13

growth13 rates of fish13 reared for four months without Ich present (031 mmday 92 mmmonth)were significantly higher than the following 8 months of growth for those same fish (022mmday 65 mmmonth) This disease-shy‐free growth rate is in fact faster than any13 otherprevious growth rates observed at the hatchery in our study

We conclude that growth rates at the Bubbling Ponds Fish Hatchery are likely as highas possible given the pond densities required to13 meet production goals and the Ich-shy‐infestedwater13 that feeds the facility Sorting practices are successful in helping as many fish as possiblereach stocking length as fast as possible Unlined ponds may be able to grow large fish at lowdensities but whatever factors allow for that growth13 are not able13 to overcome13 high fish densityThus the large lower ponds at Bubbling Ponds may be better utilized via renovation to13 deepenand line them

Disease is the most important factor limiting growth as may be expected to be the caseat many13 hatcheries While the spring renovation was not13 a complete success13 the dramaticreduction of fish populations in that habitat was enough to dramatically13 reduce13 the13 occurrenceof Ich at the hatchery13 Such open spring13 systems feeding a hatchery are a misfortune that canbe expected to transmit disease so we suggest that renovating the spring again to combat13 IchImproved techniques to divert water from13 the springs and more throuough treatment ofstream-shy‐side vegetation may improve the success of chemical treatment Successful renovationwould likely both improve growth rates and reduce chemical costs associated with treating Ichoutbreaks Even13 if complete renovation13 is impossible or impractical an13 effort to reduceinvasive fish density in the springs13 which act a vector for the parasite(and thereby reduce thelikelihood of13 Ich being transmitted into ponds) may still13 show dramatic improvements

36

13

Introduction

Conservation efforts13 for razorback sucker13 (Xyrauchen texanus)13 currently13 depend on

captive rearing and stocking programs Low survival of stocked razorback suckers (Brooks

1986 Marsh13 and13 Brooks13 1989 Marsh13 and13 Pacey13 2005) has13 caused13 target sizes for stocked13

fish to steadily increase in efforts to reduce predation mortality13 (Marsh13 et al13 2005

Schooley and Marsh 2007) Rearing fish to larger sizes at hatcheries comes with increased

costs and creates the need to evaluate husbandry and rearing practices that may affect fish

growth13 We evaluated growth13 rates13 of individual razorback suckers13 in ponds13 at Bubbling

Ponds Fish Hatchery13 using Passive Integrated13 Transponder (PIT) tags13 to13 obtain13 precise

growth information for individual fish so that valid comparisons of growth rates as related

to rearing practices can be made

Due to the critical nature of the razorback sucker stocking program we did not

design experimental studies that would require major rearrangement and potentially

reduce production of hatchery operations Instead our studies used normal variation in

production techniques and practices to isolate factors that may modify growth rates

Though this methodology dramatically limits replication and may limit our ability to

directly13 attribute13 differences in growth13 rates13 to13 the13 variables13 we13 investigate13 we13 were13 able13

to accomplish research goals without altering hatchery operations or impacting

production

From13 2009 through 2011 we conducted a series of observational13 growth13 studies to

determine growth rates of individual razorbacks at Bubbling Ponds The first set of

experiments included13 identifying13 growth13 rates13 in lined13 and13 unlined13 ponds determining

growth13 rates13 of fish at different13 sizes13 in13 relation13 to sorting13 practices and monitoring

razorback growth rates after removing the source of the ectoparasite13 Ich (Ichthiopthirus

multifiliis) from13 the hatchery water source13

Razorback growth rate in lined ponds

Our first growth study documented individual growth rates at normal density in 11

million gallon lined ponds13 over two13 years13 This is the standard13 grow-shy‐out process for

razorbacks13 at Bubbling Ponds We monitored growth of fish for a variety13 of sizes and13 the13

37

13

amount of time in a pond during the growing season These13 data give a snapshot of growth13

rates13 at the13 facility13 and13 provide13 the basis for comparisons throughout our study

Growth rate13 in an unlined pond

In addition13 to 6 ponds lined with heavy plastic13 sheeting13 Bubbling Ponds Fish13

Hatchery maintains two narrow and deep (same dimensions as lined ponds13 Figure13 4)13 and13

three large13 shallow unlined ponds These earthen13 ponds typically have vegetation and

associated aquatic invertebrates that may better simulate natural environments by

providing cover and improved food diversity or quality Therefore these unlined ponds

may be expected to produce higher growth rates and potentially improved survival that is

more similar to growth rates observed in more natural grow-shy‐out facilities13 Historically13 the13

large13 shallow13 ponds have produced very large fish when13 utilized at low13 fish density13 The

narrow13 deep earthen13 ponds are13 used to grow13 fry13 at high density in their first13 year of life

The major downside to unlined ponds is the difficulty in harvesting fish where a lined

pond might take 8-shy‐1013 people13 a half13 day13 to13 harvest13 lined13 ponds13 require13 intensive13 weeding13

to allow seines to be pulled and therefore require many more personnel-shy‐hours13 In addition13

to harvest challenges the shallow earthen ponds tend to suffer from13 dissolved oxygen

crashes during the summer Unlined ponds also may maintain higher13 populations13 of non-shy‐

target species such as bluegill sunfish mosquito fish and bullfrog tadpoles We measured

growth rates of suckers in a large shallow earthen pond for comparison to growth in lined

ponds13

Figure13 4 Lined13 and13 earthen ponds13 of similar dimensions (approx 1000000 gallons first

and second panels) and a large13 shallow13 earthen13 pond (third panel)

38

13

Effect of sorting on growth

Razorback13 suckers13 are13 currently13 sorted13 after their first13 year of growth13 They are13

typically removed from13 one of the13 upper earthen13 ponds and13 split into13 two13 lined13 ponds for

subsequent grow-shy‐out13 The larger13 fish (gt approximately 140 mm) are placed into one pond

and the smaller individuals in another It is possible that the larger fish were more

aggressive or adept13 at taking food so this sorting process is intended to allow smaller fish

to improve their growth rate

Effect of Ich on razorback sucker growth rates

We13 evaluated13 growth13 rates13 of razorback sucker13 in the13 presence13 and absence of the

ectoparasite13 Ich (Ichthiopthirus multifiliis) Ich outbreaks can occur in wild populations13 but

hatcheries13 have13 proven excellent locations13 for Ich because13 of very high fish densities13 which13

facilitate13 the13 transfer13 of Ich13 between13 fish This common fish parasite causes direct mortality13

to razorback13 suckers as well13 as secondary bacterial13 infections13

The open spring and13 ditch13 which13 provides water to the Bubbling13 Ponds Hatchery

has long13 been infested with mosquitofish (Gambusia affinis) that harbor13 the13 Ich parasite13

and allow13 it13 to enter the hatchery with incoming13 water13 The solution13 to13 the13 Ich problem13

was to remove the mosquitofish host using13 Rotenone Razorback13 sucker growth13 rates were13

then tracked in13 the absence of this parasite for 4 months and compared with growth rates

after Ich returned to the pond and from13 previous years

Methods

Razorback growth rate in lined ponds

On May 14 2008 141 razorback suckers were tagged with 12 mm PIT tags (1342

kHz) and placed in Pond 3 (approximately 1100000 gallons13 Figure13 4)13 at Bubbling13 Ponds

Fish Hatchery Fifty-shy‐three of these tags were recovered two months later when a large

Ichthyophthirius multifilis (Ich) outbreak killed many fish in the pond On October 15 2008

an additional13 145 PIT tagged13 fish were13 also placed into Pond13 3 On13 May13 14 2009 Pond13 3

was harvested and a total13 of 141 PIT tagged fish were recovered13 Of the tagged fish13 26 fish

had13 been13 in the13 pond since May13 of 2008 (378 days13 o growth) and 115 had been13 in13 the

39

13 40

pond since October13 15 2008 (211 days13 of growth) Numbers of fish in Pond 3 after the Ich

outbreak and for the majority of the period of growth were between 3 000 and 4000 fish

A Hobotempreg temperature13 logger13 was13 also13 installed13 in Pond 3 one meter below the water

surface13 near13 the13 outflow and13 recorded water temperature every 3 hours to allow analysis

of the effects of water temperature on growth rate (Figure13 5) This Hobotemp data is

representative of other pond temperatures throughout this study

In a second experiment 210 adult13 razorback suckers13 were13 PIT tagged13 on13 May 14

2009 and13 placed13 into13 Pond13 3 upper to13 evaluate13 growth13 rates13 of larger13 razorback suckers13 at

Bubbling13 Ponds Hatchery13 under current13 rearing13 conditions13 Size of these fish at tagging13

was (mean = 285 mm range = 205 ndash 396 mm) These fish remained in the pond for 257

days and were harvested on Jan 25 2010 to provide information on growth rates of larger

razorback suckers13 under13 current rearing conditions

Figure 513 Temperatures (degC) inrearing pond at BubblingPonds Hatchery from July toSept 2009 (top graph)13 andfrom Nov to Dec 2009 (Lowergraph) Temperaturesrecorded with a Hobotempregremote data logger13 every 3hours

13

Growth rate13 in an unlined pond

To document razorback sucker growth in earthen ponds we introduced13 225 tagged13

razorback suckers13 into13 Pond13 1 lower13 (Figure 4) in February 3 2010 Additional tagged fish

from13 other studies were added to the pond throughout the growing season and the density

of 1 lower reached a maximum13 of nearly 7000 fish in early summer 2010 Density was

reduced to approximately 6000 fish by capturing fish with hoop nets on June 3 2010 54 of

these fish were tagged fish and returned to 1 lower after being weighed and measured The

pond was harvested on January13 2713 2011 and a total13 of 254 tagged fish out13 of 4296 fish

total were removed from13 the pond The pond was harvested on January 27 2011 (358 days13

of growth) and the tagged fish were weighed and measured Total number of razorbacks in

the pond at harvest13 was 4296

Effect of sorting practices on growth rates

On March 1113 200913 Pond13 5 upper was13 harvested13 and13 split into13 two13 separate13 groups

Two hundred of the smaller fish (average size = 122 mm TL) were PIT tagged and placed

into13 Pond13 7 upper and13 200 of the13 larger13 fish (average = 160 mm TL) were PIT tagged and

placed int Pond13 8 upper Density13 in Pond13 7 was13 4500 fish and13 in Pond13 8 there13 were13 6500

fish These ponds were then harvested after 1 year and growth rates were compared to

give information on the effects of current sorting practices Hobotempreg temperature

loggers were installed in13 Ponds 7 and13 8 during13 the13 grow-shy‐out period with13 water13

temperature recorded every 2 hours13 (Figure13 6)

Effect of Ich on razorback sucker growth rates

Bubbling Ponds spring was treated with Rotenone (CFT Legumine 5) at a

concentration of 2 ppm13 to remove all mosquitofish from13 the spring The treatment

consisted of two treatments 6 hours in duration on two consecutive days (April 12 -shy‐ 13)

using13 drip13 stations13 and13 backpack sprayers13 followed13 by13 an13 additional 6 hours13 of

detoxification using sodium13 permanganate Although 12 mosquitofish were captured in the

spring pond the week following the treatments subsequent minnow trapping (20 traps

checked13 daily13 for 3 weeks) did not capture any additional fish until August 11 2010 when

41

13

juvenile mosquitofish were again detected in the spring pond Minnow traps have

subsequently been set daily with several hundred individuals removed To evaluate if Ich

was also again present in the spring we captured 15 mosquitofish from13 the spring pond on

three separate days and placed them13 in an aquaria at 25 degC with 5 longfin dace known to be

free of Ich These fish were monitored for 2 weeks with no signs of Ich developing This

indicates that even though mosquitofish have returned to the spring pond the parasite is no

longer present13 although how13 long13 this condition13 will13 persist13 is unknown13

On May 1113 201013 200 juvenile razorback13 suckers were harvested out13 of Pond 5

upper (2009 year Class from13 Dexter National Fish Hatchery) and were PIT tagged and

placed into Pond 8 to evaluate if growth rates at bubbling ponds hatchery have improved

following the renovation of the spring and the removal of the Ich parasite Unfortunately13

on Sept13 8 2010 Ich was13 again13 detected13 in Pond 8 and the pond was immediately seined

and 74 tagged fish were measured to obtain growth information for the 4-shy‐month period

during13 which13 the13 pond13 was13 Ich-shy‐free13

Figure13 6 Temperatures (degC) in rearingponds 7 and 8 at Bubbling Ponds Hatchery13 from March 2009 ndash March 201013 pond 7(top13 graph)13 and13 pond 8 (Lower13 graph)13 Temperatures recorded with a Hobotempregremote data logger every 3 hours

42

13

Results

Growth in Lined Ponds

Razorback suckers13 that had been13 in13 Pond 8 upper for the13 entire13 year13 grew an13

average of 0263 mmday (789 mmmonth) and razorback suckers that had been in the

pond for 7 months (Oct -shy‐ May) grew13 on13 average of 028 mmday (843 mmmonth) (Figure13

7) These growth13 rates13 did not significantly13 differ Fish density13 in Pond 3 during13 the13

majority of the growth period was13 00032 ndash 00036 fishgallon13 Additionally no13 significant

differences in growth rate were observed between fish smaller than 210 mm TL and fish

larger than 210 mm TL when all recaptured fish were combined

We also measured the growth rate of very large fish in a lined pond On Jan13 2513 201013

156 adult fish with PIT tags were recovered from13 Pond 3 upper13 These fish were13 in the13

pond for 257 days and experienced an average13 growth13 rate13 of 024mmday or 73

mmmonth (Figure13 7)13 This growth13 rate13 is slightly13 lower13 than13 the13 average13 growth13 rate13

observed13 at Bubbling13 Ponds Hatchery in other studies (0275 mmday 825 mmmonth)

but may not be biologically meaningful We would expect larger13 fish to13 have13 reduced

growth rates according to a typical Von Bertalanfy growth model (Bertalanffy 1957) but it

appears that13 over the size range we evaluated (300 -shy‐ 450 mm TL) growth rates have not

slowed significantly compared to that of smaller13 fish grown at Bubbling Ponds13 Hatchery

Growth13 of razorback suckers13 is known13 to13 slow as13 fish reach13 larger13 sizes but it appears13 this13

reduced growth rate may not really start to be biologically meaningful at Bubbling Ponds

Hatchery13 until razorback suckers13 exceed 450 mm TL

Growth in unlined ponds

Growth13 rates13 for the13 fish recaptured13 during13 the Pond 1 lower13 thinning13 (120 days13 in

the pond) was 024 plusmn 003 mmday (729 plusmn 090 mmmonth) (Figure13 8)13 Fish13 that were13 in

the pond for nearly the entire year grew13 an13 average13 of 024 plusmn 001 mmday (726 plusmn 027

mmmonth) These growth rates are surprisingly the lowest measured growth rates for

any part of our study and differ significantly from13 every other measured growth rate

except very large13 fish (Figure13 9)13 Separating13 out13 large fish that13 were in13 the pond for the

entire year makes no difference fish that were added to the pond at TL lt300 mm grew

43

13

Gro

wth

Rat

e (m

md

ay)

020

026

032

0244 plusmn 001 mmday (733 plusmn 028 mmmonth) and and those with TL gt= 300 mm at the

start of the experiment grew 022 plusmn 003 mmday (651 plusmn 101 mmmonth)

Razorback Growth Rates in Lined Ponds

Figure 7 Growth ofrazorback suckers in(mmday plusmn standard error)in Pond 8 upper in 2008-shy‐2009 An ANOVA did notdetect any significantdifferences

7 Months Full Year 300+ mm fish

Effects of sorting on growth

One hundred and seventy five tagged razorback suckers were recovered from13 Pond

8 upper13 on March13 24 2010 (378 days13 of growth)13 These were13 the13 larger sorted13 fish (gt140

mm TL) that came out of Pond13 5 on March13 11 2009 One13 hundred and13 twenty13 two13 tagged13

razorback suckers were also recovered from13 Pond13 7 upper on March13 31 2010 (385 days13 of

growth)13 These were13 the13 smaller sorted13 fish (lt140 mm TL) that came out of Pond13 5 on

March 1113 200913 No significant differences in growth rate (mmday) were observed among

larger fish in Pond 8 and smaller fish in Pond 7 (pgt005 ANOVA) (Figure 10)13 indicating

that13 sorting may have helped to offset the original slower growth trajectory of the smaller

fish Temperatures of Ponds 7 and 8 upper remained similar throughout the year13 (Figure

5)

44

13

13

13

Gro

wth

Rat

e (m

md

ay)

Gro

wth

Rat

e (m

md

ay)

020

026

032

020

026

032

Razorback Growth in an Unlined Pond

Figure 8 Growth of razorbacksuckers (mmday plusmn standard error) in Pond 1 lower (an unlined pond)in 2010-shy‐2011 An ANOVA did notdetect any significant differences

6 Months 12 Months lt 300 mm Fish 300+ mm Fish Growth Growth

Lined vs Earthen Ponds 1 year of growth

Figure 9 Growth of razorbacksuckers (mmday plusmn standard error) in lined and unlined ponds A t-shy‐test13 did not detect a significantdifference

Lined Pond Unlined Pond 1 Yr Growth 1 Yr Growth

45

13

Effect of Sorting G

row

th R

ate

(mm

day

) G

row

th R

ate

(mm

day

)

032

020

026

032

020

026

Smaller Fish Larger Fish

Effect of Ich

Figure 10 Average growthof razorback suckers(mmday plusmn standard error)that were size-shy‐sorted intosmall fish (pond 7) and largefish (pond 8) populations At-shy‐test did not detect asignificant difference

Figure 11 Average growth ofrazorback suckers (mmday plusmnstandard error) after Ich wasremovd from the hatcheryrsquos springand after Ich was again detected inthe pond The growth rate withoutIch is significantly higher than boththe rate after Ich and the ourstudyrsquos average annual growth ratein lined ponds (ANOVA p =00003)

Growth without Ich Growth With Ich Average Annual 4 months 4 months Growth Rate

46

13

Effect of Ich on razorback sucker growth rates

Seventy-shy‐four13 tagged13 razorback suckers13 were13 recovered from13 Pond 8 on September

15 2010 These fish had13 been13 in the pond for 4 months and experienced a growth rate of

032 mmday or 97 mmmonth (Figure13 11)13 This growth13 rate13 is significantly higher (p =

005 two sample t-shy‐test) than the mean growth rate for the same group13 of tagged fish after

Ich detection (022 mmday or 65 mmmonth) and significantly higher than any other

individual growth13 rates13 observed13 to13 date13 at Bubbling13 Ponds Hatchery13 (Figure13 11)13 If this13

growth13 rate13 were13 extended throughout13 the entire13 year13 fish on average from13 Ich-shy‐free13 ponds13

would be 16 mm longer than fish from13 ponds infested with Ich Studies conducted at

Bubbling Ponds hatchery in 2008 (Ward 2008) did not reveal any effects of the treatment

chemicals on razorback sucker growth rates so it13 is likely that13 the parasite outbreaks

themselves are causing reducing growth rates rather than the chemicals used to treat the

parasites13

Conclusions

Our results suggest that under typical hatchery operations (maximizing number of

fish produced)13 the growth13 rate13 of razorback13 suckers13 is relatively13 consistent at Bubbling13

Ponds hatchery13 at 02-shy‐03 mmday (6-shy‐9 mmmonth)13 but is lower than growth13 rates13 at

other13 facilities (02 ndash 18 mmday Ward et al 2007)13 This growth13 rate13 has13 been13 constant in

both lined and unlined ponds and at all fish densities we were able to measure To achieve13

growth13 rates13 substantially higher than this will likely require13 significant changes in rearing

practices that may not be practical in order to reach numerical production13 goals

Temperature is a key variable in fish growth but seasonal growth patterns

described13 above13 (Figure13 5) demonstrate that water temperatures are high enough in

winter to maintain razorback growth Differences in water temperature by season

currently13 do not fluctuate more than 10degC at Bubbling Ponds because of the continuous

supply of water flowing through each pond (approx 225 gallonsmin) These high water

flows appear to keep pond temperatures within the thermal preference13 for razorback

suckers13 (1213 -shy‐ 28 degC Bulkley and Pimentel 1983) throughout the entire year with

temperatures rarely dropping13 below 16deg13 C (Figures 513 6)13

47

13

Fish density is another key variable in fish growth and though the number of fish in

a pond during our study ranged from13 3000 to 700013 fish we13 did not find any13 correlation13

between13 density and growth rate13 This might yield two conclusions First13 razorback

growth13 may be changed equally13 by13 densities13 at the13 hatchery13 (ie13 a density13 of 3000 fish in a

pond is as stressful13 for razorbacks as a density13 of 7000 fish) An alternative is that other

factors13 such as disease outbreaks have13 stronger13 control over fish growth13 than13 density13

Fish density13 would13 have13 to13 be13 experimentally manipulated to test13 this13 and hatchery

operations (producing the maximum13 number of fish) prevented our manipulating density13

in ponds for this13 work The trouble with manipulating density demonstrates the difficulties

associated with changing13 hatchery13 practices experimenting with density would have

prevented BPH from13 meeting13 production13 goals Given that the stocking of smaller

razorbacks has met with very little success perhaps BPH goals could be changed from13

producing 12000 fish at 300+ mm per year to a smaller number of very large fish each

year Growing13 fewer13 larger13 fish could potentially be accomplished in the same time frame

as more smaller fish but a better understanding of how density alters growth rate would

be required to be confident13 of this

The very slow growth13 in the13 earthen13 unlined13 Pond 1 lower13 was very surprising We13

had13 anticipated13 that the13 diversified diet13 cover and13 other13 habitat features13 provided by13

unlined ponds would yield dramatically increased growth rates However these traits were

not enough to offset high fish densities and in fact the unlined pond in our study13 suffered

mortality to bring densities down to that observed normally in lined ponds

Our data13 suggest13 that razorbacks13 sucker13 growth13 rates13 are13 higher in lined13 ponds13

However we13 think the reasons13 for the13 very slow growth we observed13 in the13 unlined13 pond13

in our study13 is instead13 linked13 to13 the13 usage13 of Pond 1 lower13 during13 the13 study13 rather13 than13

intrinsic13 slow growth13 in earthen13 ponds First the pond was at extremely high density for at

least part of the study The volume of Pond 1 lower has not been estimated but hatchery

managers suggest 1500-shy‐2000 fish is an appropriate number of individuals so this pond

was at a very high density for much of the experiment Second dissolved oxygen is often

very low in the13 large13 earthen13 ponds during the heat of summer much lower than that of

lined ponds This will both limit the number of fish that can survive in the pond and almost

certainly13 increases stress13 of these13 fish potentially13 reducing growth13 The DO crashes also13

48

13

limit the amount of feed hatchery managers can give fish in these ponds sometimes for

days or weeks at a time which further reduces growth during warm13 weather

Our data13 suggests that13 growth rates at the Bubbling13 Ponds Fish Hatchery are likely

as high as possible given13 the pond densities required to meet production goals and the Ich-shy‐

infested water that feeds the facility Sorting practices are successful in helping as many

fish as possible reach stocking length as fast as possible Unlined ponds may be able to

grow13 large13 fish at low13 densities13 but whatever factors allow13 for that13 growth are not13 able to

overcome high fish density The removal of invasive13 fis that act as13 a host for the13 parasite13

Ich fish from13 the Bubbling13 Ponds spring13 allowed the highest13 growth rate at 032 mmday13

(96 mmmonth) but that growth rate decreased again as Ich re-shy‐infested13 the13 hatchery13

Consistently13 achieving13 growth13 rates13 as high or substantially13 higher than13 this13 will likely13

require13 significant changes in rearing practices that may not be practical in order to13 reach13

numerical production13 goals

Two major changes that might result in higher growth rates are substantially

reducing fish density and modifying the way spring water is delivered to the facility (via

either repeated chemical treatments or enclosed concrete water diversions) to eliminate

Ich from13 the hatchery source water Other potential changes not address by our work

include13 flow-shy‐training razorbacks much previous literature including MSCP-shy‐funded13 work

on razorback suckers13 suggests13 that fish growing13 in flowing water will grow13 faster than fish

in still water (Jorgensen and Jobling 1994) Furthermore there are a wide variety of

potential benefits associated with growing13 fish13 in flowing13 water in addition13 to increased

growth13 rates13 (Davidson13 199713 Castro13 et al13 2011) Another option13 for increasing13 growth13

rates13 include13 changing to13 intensive13 culture13 in large circular13 tanks

Finally given that the stocking of smaller razorbacks has met with very little

success13 perhaps13 BPH13 goals13 could13 be13 changed from13 producing 12000 fish at 300+ mm per

year to a smaller number of very large fish each year Growing fewer larger fish could

potentially be accomplished in the same time frame as more smaller fish but a better

understanding13 of how density13 alters growth13 rate13 would13 be13 required to13 be13 confident of this

49

13

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower13 Colorado13 River Multi-shy‐Species13

Conservation Program13 (LCRMSCP) under Work Task C10 We13 thank Ty Wolters13 Tom13

Burke13 and Eric13 Volkman for their support of this research and Frank Agygos and Dave

Billingsly13 of the Bubbling13 Ponds Fish Hatchery13 for their willingness to participate in13 this

research13 and13 for their technical assistance We also thank the LCRMSCP fish group from13

Boulder City13 NV for their assistance with harvesting13 ponds and tagging13 fish13

50

13

Literature13 CitedAnders P J 1998 Conservation aquaculture and endangered species can objective science13

prevail13 over risk13 anxiety Fisheries 23(11) 28-shy‐31

Anderson R O and R M Nuemann 1996 Length weight and associated structural indicesPages 447 ndash 482 in B R Murphy13 and D13 W Willis13 editors13 Fisheries techniques13 2ndedtion American Fisheries13 Society13 Bethesda13 Maryland

Bain M B J T Finn and H E Brooks 1988 Streamflow regulation and fish communitystructure13 Ecology13 69382-shy‐392

Bays J H Zarbock R Whitman and T Murphy 2005 Conceptual design and managementof native13 fish refugia on the13 lower13 Colorado13 River In13 CL Spring13 and13 S Leoneditors Proceedings of two symposia Restoring native fish to the lower ColoradoRiver13 interactions13 of native and non-shy‐native13 fishes 13ndash1413 July13 1999 Las13 Vegas13 Nevada13 Restoring13 natural function within a modified riverine environment thelower Colorado River13 8ndash913 July13 1998 U S Fish and13 Wildlife13 Service Southwestern13 Region Albuquerque New Mexico Pages 167-shy‐177

Bertalanffy L Von 1957 Quantitative laws in metabolism13 and growth13 Q Rev Biology 32217 ndash 231

Bingham T B Scheer and C McAda 2003 Propagation facilities in Grand Valley (24 RoadHatchery Horsethief13 Ponds and13 grow-shy‐out ponds) for captive13 rearing13 ofendangered13 fishes for the13 upper13 Colorado13 River basin13 Colorado River RecoveryProgram FY2003 annual project report13 US Fish and13 Wildlife13 Service GrandJunction13 4pp

Birchell G J and K Christopherson 2004 Survival growth and recruitment of larval andjuvenile razorback13 sucker (Xyrauchen texanus) introduced13 into13 floodplain13 depressions13 of the13 Green River Utah13 Final report13 Upper13 Colorado13 RiverEndangered Fish Recovery Program13 Project No C-shy‐6RZ Publication Number 04-shy‐1513 Utah13 Division of Wildlife13 Resources Salt Lake13 City13 Utah13 67 pages

Brannon E L 1993 The perpetual oversight of hatchery programs Fishery Research 1819-shy‐27

Brett J R 1979 Environmental Factors and growth pages 599-shy‐67513 InW S Hoar13 D13 J13 Randall and J R Brett (eds) Fish Physiology Volume 8 Bioenergetics and GrowthAcademic Press New York

Brooks J E 1986 Annual reintroduction and monitoring report for razorback suckerXyrauchen texanus in the Gila River Basin Arizona 1985 US Fish and WildlifeService13 Offices of Endangered13 Species and Fishery13 Resources Albuquerque 23 pp

51

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Brunson13 R E and K D13 Christopherson13 200513 Larval13 razorback13 sucker and bonytailsurvival and13 growth13 in the13 presence13 of nonnative13 fish in the13 Baeser13 floodplainwetland of the middle Green River Final report prepared for Upper13 Colorado RiverBasin Endangered Fish Recovery Program Project No C-shy‐6-shy‐rz-shy‐bt Publication13 No 05-shy‐26 Utah13 Division of Wildlife13 Resources13 Vernal13 32 pp

Bulkley R V and R Pimentel 1983 Temperature preference and avoidance by adultrazorback suckers Transactions of the American Fisheries Society 112601-shy‐607

Burke13 T13 199513 Rearing13 wild razorback13 sucker larvae in13 lake-shy‐side13 backwaters13 LakeMohave ArizonaNevada Proceedings of the Desert Fishes Council 2635

Busacker G P I R Adelman and E M Goolish13 199013 Growth13 Pages 363 ndash 387 in C BSchreck and p B Moyle editors Methods for fish biology American FisheriesSociety Bethesda Maryland

Castro V B Grisdale-shy‐Helland S J Helland T Kristensen S M Jorgensen J Helgrud13 GClaireaux A P Farrell A Krasnov and H Takle 2011 Aerobic training stimulatesgrowth and promotes disease resistance in Atlantic salmon (Salmo salar)Comparative Biochemistry and Physiology -shy‐ Part A Molecular amp IntegrativePhysiology13 160(2) 278-shy‐290

Czapla T E 2002 Facilities plan for the production of endangered fishes to meet statestocking13 plans13 as13 part of the13 Upper13 Colorado13 River Endangered13 Fish RecoveryProgram Upper Colorado River Basin Recovery Implementation Program US Fishand Wildlife Service13 Denver13 9 pp

Davidson W 1997 The effects13 of exercise13 training on teleost fish a review of recentliterature Comput Biochem Physiol 117A67ndash75

Figiel Jr C R 2005 Annual report fiscal year 2004 Willow Beach National13 Fish HatcheryUS Fish and Wildlife13 Service Willow Beach 17 pp

Figiel Jr C R M E Ulibarri G Carmichael J Seals and J N Hanson 2005 Intensive13 fish13 culture of warmwater native fishes at a coldwater fish hatchery Pages 164-shy‐16613 inProceedings of two symposia restoring native fish to the lower Colorado13 River13 interaction13 of native13 and13 non-shy‐native13 fishes July13 13-shy‐1413 1999 Las Vegas Nevada USFish and Wildlife Service Southwest Region Albuquerque New Mexico

Gerking13 S D 1978 Ecology of freshwater fish13 production13 Halstead Press13 New13 York

Gustafson W and Q Bradwisch 2000 Wahweap operation and maintenance -shy‐-shy‐ UtahColorado River Recovery Program FY 2000 annual project report Project No 29cUtah13 Division of Wildlife13 Resources Page AZ 3pp

52

13

Hamman R L 1985 Induced spawning of hatchery-shy‐reared13 razorback sucker ProgressivFish Culturist 47(3) 187-shy‐189

Hanson J N 1996 Annual report fiscal year 1996 Willow Beach National Fish HatcheryUS Fish and Wildlife Service13 Willow Beach 9pp

Irving D S Seversen and M Montagne 2004 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2004 annual project13 report Report No 29b US Fish and13 Wildlife13 Service Vernal 3pp

Jorgensen E H and13 M Jobling 1994 Feeding and13 growth13 of exercised13 and13 unexercised13 juvenile Atlantic salmon in freshwater and performance after transfer to seawaterAquaculture International 2 154-shy‐164

Kaeding L R and D B Osmundson 198913 Colorado13 Squawfish13 and13 razorback sucker grow-shy‐out pond studies as part of conservation measures for the green mountain andRuedi reservoir water sales Final report for agreement number 6-shy‐AA-shy‐60-shy‐00150

Koebele13 B P13 198513 Growth and the size hierarchy effect an experimental assessment ofthree proposed mechanisms activity differences disproportional food acquisition13 pysiological stress Environmental Biology of Fishes 12 181-shy‐188

Kretschmann A E and L L Leslie 2006 Razorback sucker (Xyrauchen texanus) status13 reproduction and recruitment in Senator Wash Reservoir CA Final Report13 to USBurea of Reclamation Cooperative Agreement No 00-shy‐FG-shy‐34-shy‐ 0009 p 32 ArizonaGame and Fish Department Phoenix

Marsh13 P13 C13 1987a13 Digestive tract13 contents13 of adult razorback suckers13 in Lake13 MohaveArizona-shy‐Nevada Transactions of the American Fisheries Society 116117-shy‐119

Marsh P C 1987b Native fishes at Buenos Aires National Wildlife Refuge and ArizonaState University Research Park Arizona opportunities for management researchand public13 education13 on13 endangered species13 Proceedings of the Desert13 FishesCouncil 1967-shy‐78

Marsh P C 1994 Rearing native Colorado River fishes in golf course ponds Arizona StateUniversity Tempe 22 + pages

Marsh13 P13 C13 200013 Fish population13 status and evaluation13 in13 the Cibola13 High Levee PondFinal report agreement number 99-shy‐FG-shy‐30-shy‐00051 US Bureau of ReclamationBoulder City13 Nevada13 20 pages

Marsh P C and C A Pacey 1998 Growth of wild adult razorback suckers13 in Lake13 Mohave13 Arizona-shy‐Nevada13 Final report13 US Bureau of Reclamation Boulder City Nevada 25pages + appendices

53

13

Marsh P C B R Kesner and C A Pacey 2005 Repatriation as s management strategy13 to13 conserve a critically13 imperiled fish species North American Journal of FisheriesManagement 25 547-shy‐556

Marsh P C and C A Pacey 2005 Immiscibility of native and non-shy‐native13 fishes Pages 59-shy‐63 inMJ13 Brouder13 CL13 Springer13 and CS13 Leon13 editors13 Proceedings of two13 symposia Restoring native fish to the lower Colorado River interactions of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 NV and13 Restoring natural13 function within a modified riverine environment the lower Colorado River13 July13 8-shy‐913 1998 Las Vegas NV US Fish and13 Wildlife13 Service Southwest Region AlbuquerqueNew Mexico

Marsh13 P13 C13 and J13 E Brooks13 198913 Predation13 by ictalurid catfishes as a deterrent13 toreestablishment of hatchery-shy‐reared13 razorback sucker The Southwestern Naturalist34188-shy‐195

Matthews R A 2005 Ichthyopthirus multifiliis Fouquet and Ichthyopthirosis infreshwater13 teleosts13 Pages13 159-shy‐218 in Advances in Parasitology volume 59 J RBaker R Muller D Rollinson (eds) Academic Press

McCarthy13 M S and W L Minckley 1987 Age estimation for razorback sucker (PiscesCatostomidae) from13 Lake Mohave Arizona and Nevada Journal of the Arizona-shy‐Nevada Academy of Science 2187-shy‐97

Minckley13 W L13 198313 Status of the razorback13 sucker13 Xyrauchen texanus (Abbot)13 in13 thelower Colorado River basin13 The Southwestern13 Naturalist13 28(2) 165-shy‐187

Minckley13 W L13 199113 Native fished of the Grand Canyon13 region an obituary13 Pages 124-shy‐177 in Colorado River ecology and dam13 management National Academy PressWashington13 DC

Minckley13 C13 O and M LaBarbara13 199913 Report13 on13 native fish grow-shy‐out facilities13 at Cibolaand Imperial National Wildlife Refuges 1993-shy‐199513 US Fish and13 Wildlife Service13 Parker Fishery Resources Office Parker Arizona

Modde13 T13 199613 Juvenile razorback sucker (Xyrauchen texanus) in a managed wetlandadjacent13 to the Green13 River13 Great13 Basin13 Naturalist13 56375-shy‐376

Modde T KP Burnham and E J Wick 1996 Population status of the razorback sucker13 inthe middle Green River (USA) Conservation13 biology 10 110-shy‐119

Modde13 T13 and G13 B Haines13 200513 Survival13 and growth of stocked razorback13 sucker andbonytail in multiple floodplain wetlands of the middle Green River under resetconditions13 Final report prepared for Upper Colorado13 River13 Basin RecoveryImplimentation Program US Fish and Wildlife Service Vernal 66 pp

54

13

Modde T Z H Bowen and D C Kitcheyan 2005 Spatial and temporal use of a spawning13 site in the middle Green River by wild hatchery-shy‐reared13 razorback suckers13 Transactions of the American Fisheries Society 134937-shy‐944

Mueller13 G13 199213 The native fish work13 group13 -shy‐ a multiagency endeavor to improve thestatus of the razorback sucker in Lake Mohave AZ-shy‐NV13 Proceedings of the DesertFishes Council 2369

Mueller G 1995 A program13 for maintaining the razorback sucker in Lake MohaveAmerican Fisheries Society Symposium 15127-shy‐135

Mueller13 G13 200613 Ecology of the bonytail13 and razorback13 sucker and the role of offchannelhabitats13 in their13 recovery Scientific13 investigations13 report 2006-shy‐5065 US GeologicalSurvey13 Denver

Mueller G and E Wick 1998 Testing of golf course ponds at Page Arizona for suitability13 as grow-shy‐out facility for razorback sucker using surplus fish from13 Ouray NationalFish Hatchery National Park Service US Fish and13 Wildlife13 Service and UtahDivision of Wildlife13 Resources 28 pages

Mueller13 G13 and T13 Burke13 200513 Survival13 of young13 razorback13 sucker (Xyrauchen texanus) inrelation to13 stocking rates13 (fishha)13 and13 in the presence13 or absence13 of predatorcommunities in Lake Mohave Arizona-shy‐Nevada13 Pages13 155-shy‐16313 in Proceedings of two13 symposia restoring native fish to the lower Colorado River interaction13 of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 Nevada US Fish and Wildlife13 Service Southwest Region Albuquerque New Mexico

Mueller13 G13 J13 Carpenter13 and P13 C13 Marsh13 200413 Cibola13 High Levee Pond annual report 2004US Geological Survey Fort Collins13 Science Center13 Colorado13 and Arizona StateUniversity Tempe 23 pages

Nesler T P K Christopherson J M Hudson C W McAda F Pfeifer and T E Czapla 2003An integrated stocking plan for razorback sucker bonytail and Colorado13 pikeminnow for the Upper Colorado River Endangered Fish Recovery ProgramAddendum13 to State Stocking Plans Upper Colorado River Basin Recovery13 Implementation Program 12 pp

Papoulias13 D and W13 L Minckley13 1992 Effects13 of foo availability13 on survival and growth13 of larval razorback suckers13 in ponds Transactions of the American Fisheries Society121340-shy‐355

Paukert13 C P D L Ward13 P J Sponholtz13 and K13 D Hilwig13 Effects13 of repeated hoopnetting13 on bonytail chub13 Journal of Freshwater13 Ecology13 20(4) 649-shy‐653

Pfeifer F M13 C Baker13 and M13 Montagne13 199913 Propagation13 facilities13 in the13 Grand Valley13 (24 Road13 Hatchery13 Horsethief13 Ponds and13 grow-shy‐out ponds) for captive rearing of

55

13

endangered13 fishes for the13 Upper Colorado13 River Basin13 Colorado13 River Recovery13 Program FY 99 annual project report Project No 29a13 US Fish and Wildlife Service13 Grand13 Junction13 5pp

Pfeifer F S Seversen and M Montagne 2003 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2003 annual reportProject No 29b13 US Fish and Wildlife13 Service Vernal13 4pp

Rabago-shy‐Castro J L Sanchez13 J G Perez-shy‐Castaneda R and13 Gonzalez-shy‐Gonzlez A 2006Effects of the prophylactic use of Romet-shy‐3013 and13 copper13 sulfate13 on growth13 condition13 and feeding13 indicies in13 channel13 catfish (Ictalurus punctatus) Aquaculture 253 343-shy‐349

Reinitz GL L E Orme and F N Hitzel 1979 Variations of body compositio and growth13 among strains of rainbow trout Transactions of the American Fisheries Society 108204-shy‐207

Ruppert13 J13 B P B Holden13 and P D Abate 1999 Age estimation and growth of razorbacksucker13 Xyrauchen texanus in Lake13 Mead Nevada Proceedings13 of the Desert FishesCouncil 3040

Schnoor K D and J Logan 2002 Operation and maintenance of JW Mumma nativeaquatic13 species restoration facility Colorado Colorado River Recovery Program FY2002 annual project report13 Project No 29d Colorado13 Division of Wildlife Alamosa3pp

Salisbury13 L13 1998 Factors13 affecting razorback13 sucker growth13 in Lake13 Mohave backwaters13 MS Thesis13 Unviersity13 of Nevada13 Las13 Vegas

Schooley J13 D13 and P C13 Marsh13 2007 Stocking of endangerdd13 razorback13 suckers13 in thelower Colorado River Basin13 over three decades 1974-shy‐2004 North American Journalof Fisheries Management 27 43-shy‐51

Severson S H H M Tyus and G B Haines 1992 An evaluation of feeds for raisingrazorback sucker Xyrauchen texanus Journal of Applied Aquaculture 155-shy‐65

Toney D P 1974 Observations13 on the13 propagation13 and13 rearing13 of two13 endangered species13 in a hatchery environment Proceedings of the Annual Conference of the Western13 Association of State Game and Fish Commissions 54 252-shy‐259

Tyus H M13 1998 Razorback sucker13 (Xyrauchen texanus) recovery plan13 University13 ofColorado Center for Limnology Boulder13 76 pages

Tyus H M13 and13 S H Severson 1990 Growth13 and13 survival of larval razorback suckers fedfive formulated diets The Progressive Fish Culturist 52197-shy‐200

56

13

Ulibarri M E 2003 Annual report fiscal year 2001 Dexter National Fish Hatchery13 andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 26 pages

Ulibarri M E 2003 Annual report fiscal year 2002 Dexter National Fish Hatchery andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 59 pages

USBR 2006 Lower13 Colorado13 River Multi-shy‐Species Conservation Program final fishaugmentation plan Boulder City 19 pp

USFWS 2002 Razorback sucker (Xyraouchen texanus) recovery goals Amendment andsupplement to the Razorback Sucker Recovery Plan13 US Fish and Wildlife Service13 Region 6 Denver13 Colorado

USFWS 1999 Annual report 1999 Ouray National Fish Hatchery Vernal 25pp

USFWS 2004 Management plan for the big-shy‐river13 fishes of the13 lower13 Colorado13 river basinamendment and supplement to the bonytail humpback chub Coloradopikeminnow and razorback sucker recovery plans

USFWS13 2005 Station13 profile13 of the13 Dexter13 National Fish Hatchery13 and Technology CenterUS Fish and Wildlife13 Service Dexter

Valdez R A P G Mangan R Smith and B Nilson 1982 Upper Colorado River fisheriesinvestigations13 inW H Miller J J Valentine D L Archer H M Tyus R A Valdezand L13 Kaeding13 editors13 Colorado River Fishery13 Project13 Part 2 Field13 investigations13 US Bureau of Reclamation Salt Lake City Utah

WBNFH 2004 Culture methods of the endangered razorback sucker Xyrauchen texanusUS Fish and Wildlife13 Service Willow Beach National Fish Hatchery13 8 pp

Ward D 2008 Effects of disease treatments on growth of razorback sucker ReportSubmitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 Inpartial fulfillment of work task C10 agreement number 06FG30039

Ward13 D13 M Childs and W Persons 2007 Factors13 affecting13 growth13 of razorback sucker13 (Xyrauchen texanus) in captivity Literature review and knowledge assessmentReport Submitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 In partial fulfillment of work task C10 agreement number 06FG30039

57

Appendices

Appendix 1 Survey Questions Survey of Razorback Sucker Culture in the

Southwestern United States

The enclosed survey is being distributed by the Arizona Game and Fish Department to razorback sucker culture facilities throughout

the Southwestern United States The purpose of this survey is to consolidate information regarding culture of this species so that

appropriate facility improvements can be considered for Bubbling Ponds Hatchery in Arizona Specifically we wish to increase

growth rate and production efficiency at the hatchery Information gathered in this survey will be summarized in a final report to US

Bureau of Reclamation in Boulder City NV and disseminated to all facilities that participate in the survey A workshop to discuss

the findings of this study as well as to share general information concerning razorback sucker culture will be organized by the

Arizona Game and Fish Department at the conclusion of this study and all participants will be invited

Thank you for taking the time to fill out this survey Please contact Mike Childs if you have questions or would like to discuss the

survey

Mike Childs

mchildssedonanet

(928) 639-1346

(928) 634-1279

Facility_____________________________________ Date___________________

Contact Phone _____________________________

ContactPerson_______________________________

Contact Email _______________________________

1 Water quality ranges at this culture facility

Season

Spring (Mar-May) Summer (Jun-Aug) Fall (Sept-Nov) Winter (Dec-Feb)

Temperature (C)

PH

DO (mgL)

PO4 (mgL)

TDS (mgL)

Hardness (mgL)

CaCO3

Pathogens

37

13

experience13 rearing13 razorback suckers13 typically13 have13 target stocking13 densities13 that13 they use

(Tables13 4 -shy‐ 5) These stocking densities have largely been determined over time by trial

and error These approximate stocking densities provide a good starting point for more

controlled13 types13 of replicated13 pond studies13

Feed ration

Razorback13 suckers are currently13 being13 fed a wide variety13 of prepared diets (Table 7)

that range from13 a slow-shy‐sinking salmon feed manufactured by Silver Cupreg to a spirulina

and krill-shy‐enhanced catfish feed made by Rangenreg Most locations are feeding 20 ndash 50

body13 weight per13 day13 Methods13 for culture13 of razorback sucker13 larvae13 in intensive13 settings13 at

fish hatcheries are well documented (Figiel 2005) and various larval fish diets have been

evaluated13 (Tyus and13 Severson 1990 Severson et al13 1992) but no standardized13 procedures

are used for feeding13 larval13 fish in13 intensive settings13

Razorback sucker larvae are also effectively reared in pond environments using

natural foods supplemented with larval fish diets and survival is high when no predators

are present13 (Mueller 2006)13 Growth rates for larval13 and early juvenile razorback13 suckers

may increase with pond fertilization Diet and physiological studies on wild razorback

suckers indicate that they feed on plankton as well as benthic organisms during their entire

life (Marsh 1987) Artificially fertilizing ponds may greatly increase production capacity

and growth rates for razorback13 sucker (Papoulias and Minckley13 1992) and warrants

further13 investigation13

Handling stress

Handling stress13 has13 been shown to13 influence growth13 rates13 Paukert13 et al (2005)

found that growth of bonytail chub was reduced by 26when compared with controls

after being13 repeatedly13 captured and handled in13 hoop13 nets13 Handling13 effects are likely13 to be

similar for razorback suckers that are repeatedly13 captured and sorted in13 a hatchery13 setting13

Razorback suckers that are handled at Willow Beach National Fish Hatchery will commonly

not eat for two weeks after handling (John Scott personal communication) This creates a

difficult situation13 for production13 facilities because13 fish13 need to be sorted to ensure13 large13

25

13

aggressive fish do not interfere with growth of smaller individuals but frequent handling

and sorting13 causes stress related reductions in13 growth13

Measuring Growth in Captive Fish

Weight is the traditional measure used to estimate growth or production in

aquaculture settings13 Groups of fish are typically13 weighed and an average individual13 weight13

is computed (Busacker et al 1990) Although this method is often logistically the easiest it

may not be the most informative for species with highly variable growth rates like

razorback suckers especially when target lengths must be reached before fish can be

stocked Weight can also be highly influenced by things like stomach fullness or

development of gonads (Busacker et al 1990) Condition factor or relative weight can also

be used to assess growth of fish but these tools may be more robust predictors of fecundity

than of growth (Anderson and Neuman 1996) For some species sexes need to be

distinguished because males and females may differ in morphology (Anderson and

Neumann 1996) Mueller (2006) analyzed growth rates based on PIT tag recaptures of 86

razorback suckers13 in High13 Levee Pond13 and13 found13 that differences13 in growth13 do not appear13

to occur until fish are over 450 mm TL at which time growth rate in males slows while

females continue to grow at a slightly higher rate This would indicate that sex may not be

an important factor to consider when examining growth rates unless the target grow-shy‐out

size is above 450 mm TL

The best measures of growth are often determined from13 the length and weight of

individuals rather than from13 groups of fish (Anderson and Nuemannn 1996) because

individual growth rates give better estimates of confidence and variance (Busacker et13 al

1990) Length frequency analysis or recapture of previously marked individuals of a known

size is likely to yield the most useful information for razorback sucker growth The success

of any of these methods depends on proper sampling procedures that are representative of

the population as a whole (Busacker et al 1990) Sampling methods that are known to be

size-shy‐biased such as trammel nets (Mueller et al 2004) or cast nets should not be used when

trying to measure growth rates13

26

13

Conclusions

For razorback sucker survival is largely associated with stocking size Additional

focused13 research13 is therefore13 needed to13 identify13 ways13 to13 increase13 growth13 rates13 of captive-shy‐

reared13 razorback sucker Growth13 rate13 in fish is controlled13 by many factors including fish

size and age temperature density and feed ration which can all be highly correlated

Growth of razorback suckers is also inherently variable which makes the task of identifying

the key factors that13 affect13 growth in13 captivity even more difficult The focus at most

razorback rearing facilities13 is production so the13 types13 of data that are13 collected13 are13 often

insufficient for detailed13 evaluations13 of individual rearing13 practices13 on growth13 Surveys of

existing13 razorback sucker13 rearing facilities indicate that culture methods vary widely and

the types of growth data13 that13 are collected are not13 standardized13 Replicated studies with

detailed information on rearing location water temperature initial stocking size stocking

density and the sizes of all fish at harvest are needed in order to compare the effects of

individual rearing practices on growth This type of research will ultimately provide both

time and cost-shy‐savings to production facilities by reducing the amount of time necessary13 for

razorback sucker to reach stocking size improving overall production efficiency

Optimum13 rearing densities for razorback sucker larvae and juveniles remain to be

determined Current stocking densities will be very useful as starting point for more

detailed studies and although optimum13 rearing densities are likely to be site-shy‐specific13

replicated studies on density will provide a valuable reference for hatchery managers

Frequency13 of sorting is another13 area that needs13 further13 research Frequent

handling13 and13 sorting13 can13 cause13 stress-shy‐related13 reductions13 in growth but not sorting can

create dominance hierarchies that further reduce growth rates of subordinate individuals

The effects13 of sorting13 on overall fish growth13 in both13 pond and13 intensive13 culture13

environments warrant further investigation Research techniques for these types of

experiments are well understood and typically utilize a matrix of replicate ponds per

variable (Bays et al 2005) In every case accurate and complete records of sampling

procedures and data collection are needed in order to interpret data and make inferences

about13 growth rates (Busacker et13 al 1990)13

27

13

Additional research is also needed to evaluate long-shy‐term13 survival of stocked fish

reared in ponds compared to fish13 reared13 in intensive13 culture13 facilities13 Exercise13

conditioning13 and predator-shy‐recognition training may also increase survival of stocked fish

and be more economically feasible than rearing fish to increasingly larger sizes prior to

stocking13 The success13 of traditional fish hatchery programs is measured largely by the

number of fish stocked but hatchery programs for endangered species must measure

success in terms of long-shy‐term13 survival and species recovery (Brannon 1993 Anders 1998)

A specific list of research recommendations follows

Specific Research13 Recommendations13

bull Use replicated studies13 to establish optimum stocking13 densities13 for ponds13 and

tanks13 that can be used as13 a starting13 point for site specific refinement

bull Determine if sortinggrading13 improves13 overall growth rates13 in both ponds13 and

intensive culture facilities13

bull Investigate the use of artificial fertilizers13 to improve growth of both juvenile

and adult razorback suckers13 in ponds13

bull Determine if the razorback sucker diet gives13 better growth rates13 than cheaper

catfish or salmon feeds

bull Evaluate growth rates13 and production potential of new intensive culture

methods13 such as13 large circular tanks13

bull Evaluate13 long-shy‐term survival of fish produced from raceways13 and circular tanks13

compared to fish reared in ponds13

bull Evaluate more effective means13 of treating13 fish diseases13

bull Evaluate factors13 other than size that may increase post-shy‐stocking13 survival such

as13 exercise conditioning13 predator recognition training or rearing13 under more

natural settings13

28

13

II The Effect of Disease Treatments on Razorback Sucker

Growth

Section13 SummaryFormalin copper sulfate potassium permanganate and13 salt are all chemicals commonly13 used13 to13 treat13 Ichthyophthirius multifiliis outbreaks in captive razorback sucker (Xyrauchen13 texanus) Weexposed 190 juvenile13 razorback suckers (127 ndash 26 mm TL) to13 5 5-shy‐day treatments with13 each13 chemical to evaluate the effects13 these chemicals13 may have on growth Fish grew an average of23513 mm TL13 during the month13 study period Fish treated with formalin grew on average13 29mm TL (03 mmday) while fish treated with copper had the lowest growth averaging 20 mmTL (021 mmday) No significant differences in13 growth were observed among fish treatedwith any of the chemicals compared to untreated fish (pgt005) Reductions in growth13 as aresult of repeated chemical treatments are not likely the cause of differences in growth ratesamong13 facilities that raise razorback suckers Repeated chemical treatments may13 have otherimpacts to overall13 fitness or long-shy‐term survival but13 these effects were not13 evident13 in our study

29

13

Introduction

Preservation13 of razorback sucker13 (Xyrauchen texanus) currently13 depends on captive13

rearing and stocking programs until permanent solutions to factors that prevent wild13

recruitment are found Low survival of stocked razorback suckers (Brooks 1986 Marsh

and Brooks 198913 Marsh and Pacey13 2005) has caused target13 sizes for stocked fish to

steadily increase in efforts to reduce predation mortality (Marsh et al 2005 Schooley and

Marsh 2007) Rearing fish to larger sizes at hatcheries comes with increased costs and

creates the need to evaluate husbandry and rearing practices that may affect fish growth

Formalin copper sulfate potassium13 permanganate and salt are all chemicals

commonly used at razorback sucker rearing facilities to treat outbreaks of the protozoan

parasite13 Ichthyophthirius multifiliis ldquoIchrdquo is one of the most pathenogenic diseases of

cultured13 freshwater13 fishes (Matthews13 2005) and causes large13 losses in captive13 populations13

of endangered razorback sucker Each of these chemicals used to treat Ich only kill the free-shy‐

swimming life stage of the parasite13 requiring13 repeated doses over several13 days depending13

on water temperature These chemicals treatments are needed to prevent loss as a result

of disease outbreaks but the cumulative effects repeated disease treatments have on

growth13 are13 unknown

Copper13 sulfate13 has13 been shown to13 significantly13 reduce13 growth13 of channel catfish13 in

production13 ponds (Rabago-shy‐Castro13 2006) but it is unknown whether13 razorback suckers13

experience similar reduced growth following copper treatment Quantifying the impacts of

disease treatments on growth will help to interpret the wide differences in growth rates

observed13 at various13 razorback sucker13 production13 facilities13 throughout the13 southwest

(Ward et al 2007) If one chemical is found to have less detrimental impacts on growth

than another then it may be preferred for use as a disease treatment We evaluated growth

rates13 of razorback suckers13 under13 replicated13 and13 controlled13 conditions13 to13 assess13 effects13 of

repeated formalin copper sulfate and potassium permanganate and salt treatments on

growth13

Methods

We captured 190 juvenile razorback suckers from13 ponds at Bubbling Ponds Fish

Hatchery AZ using hoop nets or cast nets All fish were of the same age class and

30

13

averaged 179 mm total length (TL) (range13 = 127 ndash 262 mm TL)13 These fish were13 offspring13

of captive13 razorback sucker13 broodstock held13 at Dexter13 National13 Fish Hatchery13 NM13 (2007

year class) All fish were tagged with passive integrated transponder (PIT) tags and

quarantined for one month prior to the experiment to allow fish to recover from13 tagging

and become accustomed to being held in circular tanks

At the beginning of the study all fish were weighed measured and scanned for

individual tag numbers with 19 randomly selected fish placed into each13 of 10 8-shy‐foot

diameter circular tanks (Figure 2)13 Each13 tank contained13 two13 airstones13 and13 an13 individual

biofilter with a recirculating water pump (31 litersminute) that had been operating for

at least 1 month prior to the experiment to allow bacterial colonies to become

established Two tanks were designated as a control and did not receive any chemical

treatments while the other eight tanks received formalin copper sulfate potassium13

permanganate or salt treatments at two week intervals (two tanks per chemical

treatment) Formalin copper sulfate and potassium13 permanganate were treated at 1 part

per million (ppm) and salt was applied at 30 parts per thousand (ppt) These treatment

rates are commonly used to treat13 razorback13 suckers for ich at Bubbling13 Ponds Fish13

hatchery (Frank Agygos personal communication)

Figure 213 Photo ofexperimental tankswith individualbiofilters and aeration

31

13

Each treatment consisted of a series of doses applied on Wednesday Thursday and

Friday with a 90water change between each dose Biofilters were removed from13 all

tanks and held in a separate holding facility during treatments and then replaced on the

Monday following treatments after a 90water change This schedule allowed fish to be

exposed to chemical treatments for 5 consecutive days without water quality deteriorating

This 5-shy‐day chemical treatment was repeated every two weeks from13 July to October (97

days)13 for a total of 5 5-shy‐day treatments Water temperature in the treatment tanks ranged

from13 13degC (55degF) to 32degC (91degF)

Fish were fed a fixed ration of commercial razorback diet (Silvercup 4mm13 pellet)

once daily13 (2 percent body13 weight per day13 as calculated13 by13 average initial fish weight)13

At the end of the experiment all fish were again weighed measured and scanned for

individual tag numbers Growth of fish in each treatment group was compared using

analysis of variance (ANOVA) Any mortalities13 that occurred during the13 study13 were13

replaced with previously quarantined fish of equivalent size to maintain equal densities in

each13 tank13 but growth13 data was13 only13 recorded for fish which13 survived13 the13 entire13

experiment

Results

Fish at the13 start of the experiment averaged 179 mm TL (Range13 = 127 ndash 262 mm)

with no significant differences in fish length among treatment groups (F(4189) = 00183 p

gt 0999 ANOVA) On average fish grew 235 mm TL (024 mmday) during the 3 month

study13 Fish in tanks13 treated with formalin had the highest growth averaging 29 mm TL (03

mmday) while fish in tanks treated with copper had the lowest growth averaging 20 mm

TL (021 mmday) Fish in the control tanks averaged 213 mm TL in growth (022

mmday) (Figure13 3)13 Formalin-shy‐treated fish grew13 significantly faster than13 any other

treatment group but no13 significant differences in growth13 in length13 or weight were13

observed among fish treated with any of the chemicals compared to untreated (control)

fish (pgt005 ANOVA)

32

13

Figure 313 Average growthof razorback suckersexposed to a series of 5 5-shy‐day chemical treatmentsover a 97-shy‐day13 periodError bars representstandard error

Discussion13

Growth13 rates13 observed13 in our study13 (021 ndash 03 mmday) are low compared to those

reported13 in other13 studies13 of razorback sucker13 growth13 (0213 ndash 18 mmday) (Ward et al

2007) Using recirculating water systems for our study required filters to be removed and

replaced during treatments Stress to fish caused by removing and replacing filters within

the tanks as well as repeated water changes may have led to overall higher stress and

reduced growth rates compared to those reported for unconfined fish Growth in fish is

highly variable and is affected by many different physiological and environmental factors

including fish size density temperature amount of space and food (Brett 1979) We

strived to control each of these factors but other factors may have also influenced growth

in our experimental tanks During mid-shy‐summer water temperatures in the treatment

tanks reached 32degC (91degF) At these warm13 temperatures fish are very susceptible to

bacterial13 infections13 The slightly higher growth exhibited by fish in the formalin and

potassium13 permanganate treatments may have been the result of these two chemicals

33

13

being effective at controlling bacterial infections The differences in growth we measured

among treatment groups were not statistically significant and do not appear13 biologically13

meaningful during the relatively short duration of this study (97 days) although the

cumulative effects of slightly reduced growth could be biologically meaningful over longer

time frames

Reductions in growth13 as a result13 o repeated chemical treatments are not likely the

cause of differences in growth rates among facilities that raise razorback suckers

Repeated chemical treatments may have other impacts to overall fitness or long-shy‐term13

survival but these13 effects13 were13 not evident in our study It is more likely that the parasite

outbreaks themselves are the cause of different growth rates among razorback rearing

facilities rather than the chemical treatments used to treat the parasites We recommend

that hatchery managers continue to use the chemicals that are most effective at controlling

ldquoIchrdquo13 at their individual13 facilities

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower Colorado Rive Multi-shy‐species13

Conservation Plan under Work Task C10 We thank Ty Wolters and Tom13 Burke for their

support of this research and Frank Agygos and Dave Billingsly of the Bubbling Ponds Fish

Hatchery13 for their13 technical assistance13 and13 help with13 collecting13 fish

34

13

III13 Razorback Growth Rates at Bubbling Ponds ndash 2009-shy‐2011

Section13 SummaryExperimental studies at Bubbling Ponds Fish Hatchery AZ have strived to understand

factors that affect razorback sucker growth in captivity and identify ways to improve growthrates and maximize size at release Rather than performing experimental studies that wouldrequire major13 rearrangement (and likely reduced production)13 of hatchery operations our13 studies13 used normal variation in production techniques13 and practices13 to isolate factors13 thatmay modify growth rates

Our initial work identified razorback13 growth rates in13 lined ponds at standard fishdensity as 026 to13 028mmday (789 to 843 mmmonth) No significant differences in growthrate were observed among fish that had been in the pond only during the winter13 periodcompared to fish that had been in the pond the entire year indicating that water temperatures13 at Bubbling Ponds are high enough to allow fish to incorporate feed effectively year-shy‐roundHowever these growth rates are lower than most values reported from the literature fromnatural or semi-shy‐natural pond environments No significant differences in13 growth rate wereobserved13 between large and13 small fish13 within the 150 ndash 29 mm TL13 size range Additional worksuggests13 that razorback suckers13 tagged at over 300 mm TL had reduced growth rates (024mmday 73 mmmonth) as would be expected according to a typical Von13 Bertalanfy growthcurve although growth rates13 were only slightly less13 than the average growth rate for thehatchery (027513 mmday 82513 mmmonth)

Sorting13 to13 separate small fish from large fish after the first year of growth is practicedesigned13 to allow smaller fish to ldquocatch uprdquo to larger fish We found that13 this technique doesappear to13 improve growth rates of smaller fish Growth rates of sorted small razorback suckers(029 mmday 87mmmonth)13 were equal to that13 of larger13 fish (028 mmday 8413 mmmonth)indicating that sorting may have helped to offset their original slower growth trajectory

Bubbling Ponds Fish Hatchery grows razorbacks in 6 long deep ponds lined with heavyplastic 2 long deep13 earthen13 (unlined) ponds and three wide shallow earthen ponds The wideshallow ponds13 have historically produced very large fish at low density but have been found tomaintain much lower fish numbers than deeper ponds We found13 that growth13 rates ofrazorbacks kept at high density (4-shy‐700013 fish)13 in a wide shallow pond grew extremely slowly(024 mmday 726 mmmonth) This growth rate is among the slowest of any fish over theyears of our study and demonstrates that13 though the large ponds may produce large fish at lowdensity13 they are unable to overcome high13 fish13 densities

Finally one of the major factors influencing13 fish13 growth13 in hatcheries is disease onemajor summer-shy‐time disease at13 Bubbling Ponds is the ectoparasite Ich (Ichthiopthirusmultifiliis) To investigate the impact Ich has on razorback growth we eradicated fish from thespring and water conveyance ditch that supplies13 water to the hatchery using Rotenone This13 restoration effort was fairly short-shy‐lived (Ich returned to the hatchery within four months) but

35

13

growth13 rates of fish13 reared for four months without Ich present (031 mmday 92 mmmonth)were significantly higher than the following 8 months of growth for those same fish (022mmday 65 mmmonth) This disease-shy‐free growth rate is in fact faster than any13 otherprevious growth rates observed at the hatchery in our study

We conclude that growth rates at the Bubbling Ponds Fish Hatchery are likely as highas possible given the pond densities required to13 meet production goals and the Ich-shy‐infestedwater13 that feeds the facility Sorting practices are successful in helping as many fish as possiblereach stocking length as fast as possible Unlined ponds may be able to grow large fish at lowdensities but whatever factors allow for that growth13 are not able13 to overcome13 high fish densityThus the large lower ponds at Bubbling Ponds may be better utilized via renovation to13 deepenand line them

Disease is the most important factor limiting growth as may be expected to be the caseat many13 hatcheries While the spring renovation was not13 a complete success13 the dramaticreduction of fish populations in that habitat was enough to dramatically13 reduce13 the13 occurrenceof Ich at the hatchery13 Such open spring13 systems feeding a hatchery are a misfortune that canbe expected to transmit disease so we suggest that renovating the spring again to combat13 IchImproved techniques to divert water from13 the springs and more throuough treatment ofstream-shy‐side vegetation may improve the success of chemical treatment Successful renovationwould likely both improve growth rates and reduce chemical costs associated with treating Ichoutbreaks Even13 if complete renovation13 is impossible or impractical an13 effort to reduceinvasive fish density in the springs13 which act a vector for the parasite(and thereby reduce thelikelihood of13 Ich being transmitted into ponds) may still13 show dramatic improvements

36

13

Introduction

Conservation efforts13 for razorback sucker13 (Xyrauchen texanus)13 currently13 depend on

captive rearing and stocking programs Low survival of stocked razorback suckers (Brooks

1986 Marsh13 and13 Brooks13 1989 Marsh13 and13 Pacey13 2005) has13 caused13 target sizes for stocked13

fish to steadily increase in efforts to reduce predation mortality13 (Marsh13 et al13 2005

Schooley and Marsh 2007) Rearing fish to larger sizes at hatcheries comes with increased

costs and creates the need to evaluate husbandry and rearing practices that may affect fish

growth13 We evaluated growth13 rates13 of individual razorback suckers13 in ponds13 at Bubbling

Ponds Fish Hatchery13 using Passive Integrated13 Transponder (PIT) tags13 to13 obtain13 precise

growth information for individual fish so that valid comparisons of growth rates as related

to rearing practices can be made

Due to the critical nature of the razorback sucker stocking program we did not

design experimental studies that would require major rearrangement and potentially

reduce production of hatchery operations Instead our studies used normal variation in

production techniques and practices to isolate factors that may modify growth rates

Though this methodology dramatically limits replication and may limit our ability to

directly13 attribute13 differences in growth13 rates13 to13 the13 variables13 we13 investigate13 we13 were13 able13

to accomplish research goals without altering hatchery operations or impacting

production

From13 2009 through 2011 we conducted a series of observational13 growth13 studies to

determine growth rates of individual razorbacks at Bubbling Ponds The first set of

experiments included13 identifying13 growth13 rates13 in lined13 and13 unlined13 ponds determining

growth13 rates13 of fish at different13 sizes13 in13 relation13 to sorting13 practices and monitoring

razorback growth rates after removing the source of the ectoparasite13 Ich (Ichthiopthirus

multifiliis) from13 the hatchery water source13

Razorback growth rate in lined ponds

Our first growth study documented individual growth rates at normal density in 11

million gallon lined ponds13 over two13 years13 This is the standard13 grow-shy‐out process for

razorbacks13 at Bubbling Ponds We monitored growth of fish for a variety13 of sizes and13 the13

37

13

amount of time in a pond during the growing season These13 data give a snapshot of growth13

rates13 at the13 facility13 and13 provide13 the basis for comparisons throughout our study

Growth rate13 in an unlined pond

In addition13 to 6 ponds lined with heavy plastic13 sheeting13 Bubbling Ponds Fish13

Hatchery maintains two narrow and deep (same dimensions as lined ponds13 Figure13 4)13 and13

three large13 shallow unlined ponds These earthen13 ponds typically have vegetation and

associated aquatic invertebrates that may better simulate natural environments by

providing cover and improved food diversity or quality Therefore these unlined ponds

may be expected to produce higher growth rates and potentially improved survival that is

more similar to growth rates observed in more natural grow-shy‐out facilities13 Historically13 the13

large13 shallow13 ponds have produced very large fish when13 utilized at low13 fish density13 The

narrow13 deep earthen13 ponds are13 used to grow13 fry13 at high density in their first13 year of life

The major downside to unlined ponds is the difficulty in harvesting fish where a lined

pond might take 8-shy‐1013 people13 a half13 day13 to13 harvest13 lined13 ponds13 require13 intensive13 weeding13

to allow seines to be pulled and therefore require many more personnel-shy‐hours13 In addition13

to harvest challenges the shallow earthen ponds tend to suffer from13 dissolved oxygen

crashes during the summer Unlined ponds also may maintain higher13 populations13 of non-shy‐

target species such as bluegill sunfish mosquito fish and bullfrog tadpoles We measured

growth rates of suckers in a large shallow earthen pond for comparison to growth in lined

ponds13

Figure13 4 Lined13 and13 earthen ponds13 of similar dimensions (approx 1000000 gallons first

and second panels) and a large13 shallow13 earthen13 pond (third panel)

38

13

Effect of sorting on growth

Razorback13 suckers13 are13 currently13 sorted13 after their first13 year of growth13 They are13

typically removed from13 one of the13 upper earthen13 ponds and13 split into13 two13 lined13 ponds for

subsequent grow-shy‐out13 The larger13 fish (gt approximately 140 mm) are placed into one pond

and the smaller individuals in another It is possible that the larger fish were more

aggressive or adept13 at taking food so this sorting process is intended to allow smaller fish

to improve their growth rate

Effect of Ich on razorback sucker growth rates

We13 evaluated13 growth13 rates13 of razorback sucker13 in the13 presence13 and absence of the

ectoparasite13 Ich (Ichthiopthirus multifiliis) Ich outbreaks can occur in wild populations13 but

hatcheries13 have13 proven excellent locations13 for Ich because13 of very high fish densities13 which13

facilitate13 the13 transfer13 of Ich13 between13 fish This common fish parasite causes direct mortality13

to razorback13 suckers as well13 as secondary bacterial13 infections13

The open spring and13 ditch13 which13 provides water to the Bubbling13 Ponds Hatchery

has long13 been infested with mosquitofish (Gambusia affinis) that harbor13 the13 Ich parasite13

and allow13 it13 to enter the hatchery with incoming13 water13 The solution13 to13 the13 Ich problem13

was to remove the mosquitofish host using13 Rotenone Razorback13 sucker growth13 rates were13

then tracked in13 the absence of this parasite for 4 months and compared with growth rates

after Ich returned to the pond and from13 previous years

Methods

Razorback growth rate in lined ponds

On May 14 2008 141 razorback suckers were tagged with 12 mm PIT tags (1342

kHz) and placed in Pond 3 (approximately 1100000 gallons13 Figure13 4)13 at Bubbling13 Ponds

Fish Hatchery Fifty-shy‐three of these tags were recovered two months later when a large

Ichthyophthirius multifilis (Ich) outbreak killed many fish in the pond On October 15 2008

an additional13 145 PIT tagged13 fish were13 also placed into Pond13 3 On13 May13 14 2009 Pond13 3

was harvested and a total13 of 141 PIT tagged fish were recovered13 Of the tagged fish13 26 fish

had13 been13 in the13 pond since May13 of 2008 (378 days13 o growth) and 115 had been13 in13 the

39

13 40

pond since October13 15 2008 (211 days13 of growth) Numbers of fish in Pond 3 after the Ich

outbreak and for the majority of the period of growth were between 3 000 and 4000 fish

A Hobotempreg temperature13 logger13 was13 also13 installed13 in Pond 3 one meter below the water

surface13 near13 the13 outflow and13 recorded water temperature every 3 hours to allow analysis

of the effects of water temperature on growth rate (Figure13 5) This Hobotemp data is

representative of other pond temperatures throughout this study

In a second experiment 210 adult13 razorback suckers13 were13 PIT tagged13 on13 May 14

2009 and13 placed13 into13 Pond13 3 upper to13 evaluate13 growth13 rates13 of larger13 razorback suckers13 at

Bubbling13 Ponds Hatchery13 under current13 rearing13 conditions13 Size of these fish at tagging13

was (mean = 285 mm range = 205 ndash 396 mm) These fish remained in the pond for 257

days and were harvested on Jan 25 2010 to provide information on growth rates of larger

razorback suckers13 under13 current rearing conditions

Figure 513 Temperatures (degC) inrearing pond at BubblingPonds Hatchery from July toSept 2009 (top graph)13 andfrom Nov to Dec 2009 (Lowergraph) Temperaturesrecorded with a Hobotempregremote data logger13 every 3hours

13

Growth rate13 in an unlined pond

To document razorback sucker growth in earthen ponds we introduced13 225 tagged13

razorback suckers13 into13 Pond13 1 lower13 (Figure 4) in February 3 2010 Additional tagged fish

from13 other studies were added to the pond throughout the growing season and the density

of 1 lower reached a maximum13 of nearly 7000 fish in early summer 2010 Density was

reduced to approximately 6000 fish by capturing fish with hoop nets on June 3 2010 54 of

these fish were tagged fish and returned to 1 lower after being weighed and measured The

pond was harvested on January13 2713 2011 and a total13 of 254 tagged fish out13 of 4296 fish

total were removed from13 the pond The pond was harvested on January 27 2011 (358 days13

of growth) and the tagged fish were weighed and measured Total number of razorbacks in

the pond at harvest13 was 4296

Effect of sorting practices on growth rates

On March 1113 200913 Pond13 5 upper was13 harvested13 and13 split into13 two13 separate13 groups

Two hundred of the smaller fish (average size = 122 mm TL) were PIT tagged and placed

into13 Pond13 7 upper and13 200 of the13 larger13 fish (average = 160 mm TL) were PIT tagged and

placed int Pond13 8 upper Density13 in Pond13 7 was13 4500 fish and13 in Pond13 8 there13 were13 6500

fish These ponds were then harvested after 1 year and growth rates were compared to

give information on the effects of current sorting practices Hobotempreg temperature

loggers were installed in13 Ponds 7 and13 8 during13 the13 grow-shy‐out period with13 water13

temperature recorded every 2 hours13 (Figure13 6)

Effect of Ich on razorback sucker growth rates

Bubbling Ponds spring was treated with Rotenone (CFT Legumine 5) at a

concentration of 2 ppm13 to remove all mosquitofish from13 the spring The treatment

consisted of two treatments 6 hours in duration on two consecutive days (April 12 -shy‐ 13)

using13 drip13 stations13 and13 backpack sprayers13 followed13 by13 an13 additional 6 hours13 of

detoxification using sodium13 permanganate Although 12 mosquitofish were captured in the

spring pond the week following the treatments subsequent minnow trapping (20 traps

checked13 daily13 for 3 weeks) did not capture any additional fish until August 11 2010 when

41

13

juvenile mosquitofish were again detected in the spring pond Minnow traps have

subsequently been set daily with several hundred individuals removed To evaluate if Ich

was also again present in the spring we captured 15 mosquitofish from13 the spring pond on

three separate days and placed them13 in an aquaria at 25 degC with 5 longfin dace known to be

free of Ich These fish were monitored for 2 weeks with no signs of Ich developing This

indicates that even though mosquitofish have returned to the spring pond the parasite is no

longer present13 although how13 long13 this condition13 will13 persist13 is unknown13

On May 1113 201013 200 juvenile razorback13 suckers were harvested out13 of Pond 5

upper (2009 year Class from13 Dexter National Fish Hatchery) and were PIT tagged and

placed into Pond 8 to evaluate if growth rates at bubbling ponds hatchery have improved

following the renovation of the spring and the removal of the Ich parasite Unfortunately13

on Sept13 8 2010 Ich was13 again13 detected13 in Pond 8 and the pond was immediately seined

and 74 tagged fish were measured to obtain growth information for the 4-shy‐month period

during13 which13 the13 pond13 was13 Ich-shy‐free13

Figure13 6 Temperatures (degC) in rearingponds 7 and 8 at Bubbling Ponds Hatchery13 from March 2009 ndash March 201013 pond 7(top13 graph)13 and13 pond 8 (Lower13 graph)13 Temperatures recorded with a Hobotempregremote data logger every 3 hours

42

13

Results

Growth in Lined Ponds

Razorback suckers13 that had been13 in13 Pond 8 upper for the13 entire13 year13 grew an13

average of 0263 mmday (789 mmmonth) and razorback suckers that had been in the

pond for 7 months (Oct -shy‐ May) grew13 on13 average of 028 mmday (843 mmmonth) (Figure13

7) These growth13 rates13 did not significantly13 differ Fish density13 in Pond 3 during13 the13

majority of the growth period was13 00032 ndash 00036 fishgallon13 Additionally no13 significant

differences in growth rate were observed between fish smaller than 210 mm TL and fish

larger than 210 mm TL when all recaptured fish were combined

We also measured the growth rate of very large fish in a lined pond On Jan13 2513 201013

156 adult fish with PIT tags were recovered from13 Pond 3 upper13 These fish were13 in the13

pond for 257 days and experienced an average13 growth13 rate13 of 024mmday or 73

mmmonth (Figure13 7)13 This growth13 rate13 is slightly13 lower13 than13 the13 average13 growth13 rate13

observed13 at Bubbling13 Ponds Hatchery in other studies (0275 mmday 825 mmmonth)

but may not be biologically meaningful We would expect larger13 fish to13 have13 reduced

growth rates according to a typical Von Bertalanfy growth model (Bertalanffy 1957) but it

appears that13 over the size range we evaluated (300 -shy‐ 450 mm TL) growth rates have not

slowed significantly compared to that of smaller13 fish grown at Bubbling Ponds13 Hatchery

Growth13 of razorback suckers13 is known13 to13 slow as13 fish reach13 larger13 sizes but it appears13 this13

reduced growth rate may not really start to be biologically meaningful at Bubbling Ponds

Hatchery13 until razorback suckers13 exceed 450 mm TL

Growth in unlined ponds

Growth13 rates13 for the13 fish recaptured13 during13 the Pond 1 lower13 thinning13 (120 days13 in

the pond) was 024 plusmn 003 mmday (729 plusmn 090 mmmonth) (Figure13 8)13 Fish13 that were13 in

the pond for nearly the entire year grew13 an13 average13 of 024 plusmn 001 mmday (726 plusmn 027

mmmonth) These growth rates are surprisingly the lowest measured growth rates for

any part of our study and differ significantly from13 every other measured growth rate

except very large13 fish (Figure13 9)13 Separating13 out13 large fish that13 were in13 the pond for the

entire year makes no difference fish that were added to the pond at TL lt300 mm grew

43

13

Gro

wth

Rat

e (m

md

ay)

020

026

032

0244 plusmn 001 mmday (733 plusmn 028 mmmonth) and and those with TL gt= 300 mm at the

start of the experiment grew 022 plusmn 003 mmday (651 plusmn 101 mmmonth)

Razorback Growth Rates in Lined Ponds

Figure 7 Growth ofrazorback suckers in(mmday plusmn standard error)in Pond 8 upper in 2008-shy‐2009 An ANOVA did notdetect any significantdifferences

7 Months Full Year 300+ mm fish

Effects of sorting on growth

One hundred and seventy five tagged razorback suckers were recovered from13 Pond

8 upper13 on March13 24 2010 (378 days13 of growth)13 These were13 the13 larger sorted13 fish (gt140

mm TL) that came out of Pond13 5 on March13 11 2009 One13 hundred and13 twenty13 two13 tagged13

razorback suckers were also recovered from13 Pond13 7 upper on March13 31 2010 (385 days13 of

growth)13 These were13 the13 smaller sorted13 fish (lt140 mm TL) that came out of Pond13 5 on

March 1113 200913 No significant differences in growth rate (mmday) were observed among

larger fish in Pond 8 and smaller fish in Pond 7 (pgt005 ANOVA) (Figure 10)13 indicating

that13 sorting may have helped to offset the original slower growth trajectory of the smaller

fish Temperatures of Ponds 7 and 8 upper remained similar throughout the year13 (Figure

5)

44

13

13

13

Gro

wth

Rat

e (m

md

ay)

Gro

wth

Rat

e (m

md

ay)

020

026

032

020

026

032

Razorback Growth in an Unlined Pond

Figure 8 Growth of razorbacksuckers (mmday plusmn standard error) in Pond 1 lower (an unlined pond)in 2010-shy‐2011 An ANOVA did notdetect any significant differences

6 Months 12 Months lt 300 mm Fish 300+ mm Fish Growth Growth

Lined vs Earthen Ponds 1 year of growth

Figure 9 Growth of razorbacksuckers (mmday plusmn standard error) in lined and unlined ponds A t-shy‐test13 did not detect a significantdifference

Lined Pond Unlined Pond 1 Yr Growth 1 Yr Growth

45

13

Effect of Sorting G

row

th R

ate

(mm

day

) G

row

th R

ate

(mm

day

)

032

020

026

032

020

026

Smaller Fish Larger Fish

Effect of Ich

Figure 10 Average growthof razorback suckers(mmday plusmn standard error)that were size-shy‐sorted intosmall fish (pond 7) and largefish (pond 8) populations At-shy‐test did not detect asignificant difference

Figure 11 Average growth ofrazorback suckers (mmday plusmnstandard error) after Ich wasremovd from the hatcheryrsquos springand after Ich was again detected inthe pond The growth rate withoutIch is significantly higher than boththe rate after Ich and the ourstudyrsquos average annual growth ratein lined ponds (ANOVA p =00003)

Growth without Ich Growth With Ich Average Annual 4 months 4 months Growth Rate

46

13

Effect of Ich on razorback sucker growth rates

Seventy-shy‐four13 tagged13 razorback suckers13 were13 recovered from13 Pond 8 on September

15 2010 These fish had13 been13 in the pond for 4 months and experienced a growth rate of

032 mmday or 97 mmmonth (Figure13 11)13 This growth13 rate13 is significantly higher (p =

005 two sample t-shy‐test) than the mean growth rate for the same group13 of tagged fish after

Ich detection (022 mmday or 65 mmmonth) and significantly higher than any other

individual growth13 rates13 observed13 to13 date13 at Bubbling13 Ponds Hatchery13 (Figure13 11)13 If this13

growth13 rate13 were13 extended throughout13 the entire13 year13 fish on average from13 Ich-shy‐free13 ponds13

would be 16 mm longer than fish from13 ponds infested with Ich Studies conducted at

Bubbling Ponds hatchery in 2008 (Ward 2008) did not reveal any effects of the treatment

chemicals on razorback sucker growth rates so it13 is likely that13 the parasite outbreaks

themselves are causing reducing growth rates rather than the chemicals used to treat the

parasites13

Conclusions

Our results suggest that under typical hatchery operations (maximizing number of

fish produced)13 the growth13 rate13 of razorback13 suckers13 is relatively13 consistent at Bubbling13

Ponds hatchery13 at 02-shy‐03 mmday (6-shy‐9 mmmonth)13 but is lower than growth13 rates13 at

other13 facilities (02 ndash 18 mmday Ward et al 2007)13 This growth13 rate13 has13 been13 constant in

both lined and unlined ponds and at all fish densities we were able to measure To achieve13

growth13 rates13 substantially higher than this will likely require13 significant changes in rearing

practices that may not be practical in order to reach numerical production13 goals

Temperature is a key variable in fish growth but seasonal growth patterns

described13 above13 (Figure13 5) demonstrate that water temperatures are high enough in

winter to maintain razorback growth Differences in water temperature by season

currently13 do not fluctuate more than 10degC at Bubbling Ponds because of the continuous

supply of water flowing through each pond (approx 225 gallonsmin) These high water

flows appear to keep pond temperatures within the thermal preference13 for razorback

suckers13 (1213 -shy‐ 28 degC Bulkley and Pimentel 1983) throughout the entire year with

temperatures rarely dropping13 below 16deg13 C (Figures 513 6)13

47

13

Fish density is another key variable in fish growth and though the number of fish in

a pond during our study ranged from13 3000 to 700013 fish we13 did not find any13 correlation13

between13 density and growth rate13 This might yield two conclusions First13 razorback

growth13 may be changed equally13 by13 densities13 at the13 hatchery13 (ie13 a density13 of 3000 fish in a

pond is as stressful13 for razorbacks as a density13 of 7000 fish) An alternative is that other

factors13 such as disease outbreaks have13 stronger13 control over fish growth13 than13 density13

Fish density13 would13 have13 to13 be13 experimentally manipulated to test13 this13 and hatchery

operations (producing the maximum13 number of fish) prevented our manipulating density13

in ponds for this13 work The trouble with manipulating density demonstrates the difficulties

associated with changing13 hatchery13 practices experimenting with density would have

prevented BPH from13 meeting13 production13 goals Given that the stocking of smaller

razorbacks has met with very little success perhaps BPH goals could be changed from13

producing 12000 fish at 300+ mm per year to a smaller number of very large fish each

year Growing13 fewer13 larger13 fish could potentially be accomplished in the same time frame

as more smaller fish but a better understanding of how density alters growth rate would

be required to be confident13 of this

The very slow growth13 in the13 earthen13 unlined13 Pond 1 lower13 was very surprising We13

had13 anticipated13 that the13 diversified diet13 cover and13 other13 habitat features13 provided by13

unlined ponds would yield dramatically increased growth rates However these traits were

not enough to offset high fish densities and in fact the unlined pond in our study13 suffered

mortality to bring densities down to that observed normally in lined ponds

Our data13 suggest13 that razorbacks13 sucker13 growth13 rates13 are13 higher in lined13 ponds13

However we13 think the reasons13 for the13 very slow growth we observed13 in the13 unlined13 pond13

in our study13 is instead13 linked13 to13 the13 usage13 of Pond 1 lower13 during13 the13 study13 rather13 than13

intrinsic13 slow growth13 in earthen13 ponds First the pond was at extremely high density for at

least part of the study The volume of Pond 1 lower has not been estimated but hatchery

managers suggest 1500-shy‐2000 fish is an appropriate number of individuals so this pond

was at a very high density for much of the experiment Second dissolved oxygen is often

very low in the13 large13 earthen13 ponds during the heat of summer much lower than that of

lined ponds This will both limit the number of fish that can survive in the pond and almost

certainly13 increases stress13 of these13 fish potentially13 reducing growth13 The DO crashes also13

48

13

limit the amount of feed hatchery managers can give fish in these ponds sometimes for

days or weeks at a time which further reduces growth during warm13 weather

Our data13 suggests that13 growth rates at the Bubbling13 Ponds Fish Hatchery are likely

as high as possible given13 the pond densities required to meet production goals and the Ich-shy‐

infested water that feeds the facility Sorting practices are successful in helping as many

fish as possible reach stocking length as fast as possible Unlined ponds may be able to

grow13 large13 fish at low13 densities13 but whatever factors allow13 for that13 growth are not13 able to

overcome high fish density The removal of invasive13 fis that act as13 a host for the13 parasite13

Ich fish from13 the Bubbling13 Ponds spring13 allowed the highest13 growth rate at 032 mmday13

(96 mmmonth) but that growth rate decreased again as Ich re-shy‐infested13 the13 hatchery13

Consistently13 achieving13 growth13 rates13 as high or substantially13 higher than13 this13 will likely13

require13 significant changes in rearing practices that may not be practical in order to13 reach13

numerical production13 goals

Two major changes that might result in higher growth rates are substantially

reducing fish density and modifying the way spring water is delivered to the facility (via

either repeated chemical treatments or enclosed concrete water diversions) to eliminate

Ich from13 the hatchery source water Other potential changes not address by our work

include13 flow-shy‐training razorbacks much previous literature including MSCP-shy‐funded13 work

on razorback suckers13 suggests13 that fish growing13 in flowing water will grow13 faster than fish

in still water (Jorgensen and Jobling 1994) Furthermore there are a wide variety of

potential benefits associated with growing13 fish13 in flowing13 water in addition13 to increased

growth13 rates13 (Davidson13 199713 Castro13 et al13 2011) Another option13 for increasing13 growth13

rates13 include13 changing to13 intensive13 culture13 in large circular13 tanks

Finally given that the stocking of smaller razorbacks has met with very little

success13 perhaps13 BPH13 goals13 could13 be13 changed from13 producing 12000 fish at 300+ mm per

year to a smaller number of very large fish each year Growing fewer larger fish could

potentially be accomplished in the same time frame as more smaller fish but a better

understanding13 of how density13 alters growth13 rate13 would13 be13 required to13 be13 confident of this

49

13

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower13 Colorado13 River Multi-shy‐Species13

Conservation Program13 (LCRMSCP) under Work Task C10 We13 thank Ty Wolters13 Tom13

Burke13 and Eric13 Volkman for their support of this research and Frank Agygos and Dave

Billingsly13 of the Bubbling13 Ponds Fish Hatchery13 for their willingness to participate in13 this

research13 and13 for their technical assistance We also thank the LCRMSCP fish group from13

Boulder City13 NV for their assistance with harvesting13 ponds and tagging13 fish13

50

13

Literature13 CitedAnders P J 1998 Conservation aquaculture and endangered species can objective science13

prevail13 over risk13 anxiety Fisheries 23(11) 28-shy‐31

Anderson R O and R M Nuemann 1996 Length weight and associated structural indicesPages 447 ndash 482 in B R Murphy13 and D13 W Willis13 editors13 Fisheries techniques13 2ndedtion American Fisheries13 Society13 Bethesda13 Maryland

Bain M B J T Finn and H E Brooks 1988 Streamflow regulation and fish communitystructure13 Ecology13 69382-shy‐392

Bays J H Zarbock R Whitman and T Murphy 2005 Conceptual design and managementof native13 fish refugia on the13 lower13 Colorado13 River In13 CL Spring13 and13 S Leoneditors Proceedings of two symposia Restoring native fish to the lower ColoradoRiver13 interactions13 of native and non-shy‐native13 fishes 13ndash1413 July13 1999 Las13 Vegas13 Nevada13 Restoring13 natural function within a modified riverine environment thelower Colorado River13 8ndash913 July13 1998 U S Fish and13 Wildlife13 Service Southwestern13 Region Albuquerque New Mexico Pages 167-shy‐177

Bertalanffy L Von 1957 Quantitative laws in metabolism13 and growth13 Q Rev Biology 32217 ndash 231

Bingham T B Scheer and C McAda 2003 Propagation facilities in Grand Valley (24 RoadHatchery Horsethief13 Ponds and13 grow-shy‐out ponds) for captive13 rearing13 ofendangered13 fishes for the13 upper13 Colorado13 River basin13 Colorado River RecoveryProgram FY2003 annual project report13 US Fish and13 Wildlife13 Service GrandJunction13 4pp

Birchell G J and K Christopherson 2004 Survival growth and recruitment of larval andjuvenile razorback13 sucker (Xyrauchen texanus) introduced13 into13 floodplain13 depressions13 of the13 Green River Utah13 Final report13 Upper13 Colorado13 RiverEndangered Fish Recovery Program13 Project No C-shy‐6RZ Publication Number 04-shy‐1513 Utah13 Division of Wildlife13 Resources Salt Lake13 City13 Utah13 67 pages

Brannon E L 1993 The perpetual oversight of hatchery programs Fishery Research 1819-shy‐27

Brett J R 1979 Environmental Factors and growth pages 599-shy‐67513 InW S Hoar13 D13 J13 Randall and J R Brett (eds) Fish Physiology Volume 8 Bioenergetics and GrowthAcademic Press New York

Brooks J E 1986 Annual reintroduction and monitoring report for razorback suckerXyrauchen texanus in the Gila River Basin Arizona 1985 US Fish and WildlifeService13 Offices of Endangered13 Species and Fishery13 Resources Albuquerque 23 pp

51

13

Brunson13 R E and K D13 Christopherson13 200513 Larval13 razorback13 sucker and bonytailsurvival and13 growth13 in the13 presence13 of nonnative13 fish in the13 Baeser13 floodplainwetland of the middle Green River Final report prepared for Upper13 Colorado RiverBasin Endangered Fish Recovery Program Project No C-shy‐6-shy‐rz-shy‐bt Publication13 No 05-shy‐26 Utah13 Division of Wildlife13 Resources13 Vernal13 32 pp

Bulkley R V and R Pimentel 1983 Temperature preference and avoidance by adultrazorback suckers Transactions of the American Fisheries Society 112601-shy‐607

Burke13 T13 199513 Rearing13 wild razorback13 sucker larvae in13 lake-shy‐side13 backwaters13 LakeMohave ArizonaNevada Proceedings of the Desert Fishes Council 2635

Busacker G P I R Adelman and E M Goolish13 199013 Growth13 Pages 363 ndash 387 in C BSchreck and p B Moyle editors Methods for fish biology American FisheriesSociety Bethesda Maryland

Castro V B Grisdale-shy‐Helland S J Helland T Kristensen S M Jorgensen J Helgrud13 GClaireaux A P Farrell A Krasnov and H Takle 2011 Aerobic training stimulatesgrowth and promotes disease resistance in Atlantic salmon (Salmo salar)Comparative Biochemistry and Physiology -shy‐ Part A Molecular amp IntegrativePhysiology13 160(2) 278-shy‐290

Czapla T E 2002 Facilities plan for the production of endangered fishes to meet statestocking13 plans13 as13 part of the13 Upper13 Colorado13 River Endangered13 Fish RecoveryProgram Upper Colorado River Basin Recovery Implementation Program US Fishand Wildlife Service13 Denver13 9 pp

Davidson W 1997 The effects13 of exercise13 training on teleost fish a review of recentliterature Comput Biochem Physiol 117A67ndash75

Figiel Jr C R 2005 Annual report fiscal year 2004 Willow Beach National13 Fish HatcheryUS Fish and Wildlife13 Service Willow Beach 17 pp

Figiel Jr C R M E Ulibarri G Carmichael J Seals and J N Hanson 2005 Intensive13 fish13 culture of warmwater native fishes at a coldwater fish hatchery Pages 164-shy‐16613 inProceedings of two symposia restoring native fish to the lower Colorado13 River13 interaction13 of native13 and13 non-shy‐native13 fishes July13 13-shy‐1413 1999 Las Vegas Nevada USFish and Wildlife Service Southwest Region Albuquerque New Mexico

Gerking13 S D 1978 Ecology of freshwater fish13 production13 Halstead Press13 New13 York

Gustafson W and Q Bradwisch 2000 Wahweap operation and maintenance -shy‐-shy‐ UtahColorado River Recovery Program FY 2000 annual project report Project No 29cUtah13 Division of Wildlife13 Resources Page AZ 3pp

52

13

Hamman R L 1985 Induced spawning of hatchery-shy‐reared13 razorback sucker ProgressivFish Culturist 47(3) 187-shy‐189

Hanson J N 1996 Annual report fiscal year 1996 Willow Beach National Fish HatcheryUS Fish and Wildlife Service13 Willow Beach 9pp

Irving D S Seversen and M Montagne 2004 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2004 annual project13 report Report No 29b US Fish and13 Wildlife13 Service Vernal 3pp

Jorgensen E H and13 M Jobling 1994 Feeding and13 growth13 of exercised13 and13 unexercised13 juvenile Atlantic salmon in freshwater and performance after transfer to seawaterAquaculture International 2 154-shy‐164

Kaeding L R and D B Osmundson 198913 Colorado13 Squawfish13 and13 razorback sucker grow-shy‐out pond studies as part of conservation measures for the green mountain andRuedi reservoir water sales Final report for agreement number 6-shy‐AA-shy‐60-shy‐00150

Koebele13 B P13 198513 Growth and the size hierarchy effect an experimental assessment ofthree proposed mechanisms activity differences disproportional food acquisition13 pysiological stress Environmental Biology of Fishes 12 181-shy‐188

Kretschmann A E and L L Leslie 2006 Razorback sucker (Xyrauchen texanus) status13 reproduction and recruitment in Senator Wash Reservoir CA Final Report13 to USBurea of Reclamation Cooperative Agreement No 00-shy‐FG-shy‐34-shy‐ 0009 p 32 ArizonaGame and Fish Department Phoenix

Marsh13 P13 C13 1987a13 Digestive tract13 contents13 of adult razorback suckers13 in Lake13 MohaveArizona-shy‐Nevada Transactions of the American Fisheries Society 116117-shy‐119

Marsh P C 1987b Native fishes at Buenos Aires National Wildlife Refuge and ArizonaState University Research Park Arizona opportunities for management researchand public13 education13 on13 endangered species13 Proceedings of the Desert13 FishesCouncil 1967-shy‐78

Marsh P C 1994 Rearing native Colorado River fishes in golf course ponds Arizona StateUniversity Tempe 22 + pages

Marsh13 P13 C13 200013 Fish population13 status and evaluation13 in13 the Cibola13 High Levee PondFinal report agreement number 99-shy‐FG-shy‐30-shy‐00051 US Bureau of ReclamationBoulder City13 Nevada13 20 pages

Marsh P C and C A Pacey 1998 Growth of wild adult razorback suckers13 in Lake13 Mohave13 Arizona-shy‐Nevada13 Final report13 US Bureau of Reclamation Boulder City Nevada 25pages + appendices

53

13

Marsh P C B R Kesner and C A Pacey 2005 Repatriation as s management strategy13 to13 conserve a critically13 imperiled fish species North American Journal of FisheriesManagement 25 547-shy‐556

Marsh P C and C A Pacey 2005 Immiscibility of native and non-shy‐native13 fishes Pages 59-shy‐63 inMJ13 Brouder13 CL13 Springer13 and CS13 Leon13 editors13 Proceedings of two13 symposia Restoring native fish to the lower Colorado River interactions of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 NV and13 Restoring natural13 function within a modified riverine environment the lower Colorado River13 July13 8-shy‐913 1998 Las Vegas NV US Fish and13 Wildlife13 Service Southwest Region AlbuquerqueNew Mexico

Marsh13 P13 C13 and J13 E Brooks13 198913 Predation13 by ictalurid catfishes as a deterrent13 toreestablishment of hatchery-shy‐reared13 razorback sucker The Southwestern Naturalist34188-shy‐195

Matthews R A 2005 Ichthyopthirus multifiliis Fouquet and Ichthyopthirosis infreshwater13 teleosts13 Pages13 159-shy‐218 in Advances in Parasitology volume 59 J RBaker R Muller D Rollinson (eds) Academic Press

McCarthy13 M S and W L Minckley 1987 Age estimation for razorback sucker (PiscesCatostomidae) from13 Lake Mohave Arizona and Nevada Journal of the Arizona-shy‐Nevada Academy of Science 2187-shy‐97

Minckley13 W L13 198313 Status of the razorback13 sucker13 Xyrauchen texanus (Abbot)13 in13 thelower Colorado River basin13 The Southwestern13 Naturalist13 28(2) 165-shy‐187

Minckley13 W L13 199113 Native fished of the Grand Canyon13 region an obituary13 Pages 124-shy‐177 in Colorado River ecology and dam13 management National Academy PressWashington13 DC

Minckley13 C13 O and M LaBarbara13 199913 Report13 on13 native fish grow-shy‐out facilities13 at Cibolaand Imperial National Wildlife Refuges 1993-shy‐199513 US Fish and13 Wildlife Service13 Parker Fishery Resources Office Parker Arizona

Modde13 T13 199613 Juvenile razorback sucker (Xyrauchen texanus) in a managed wetlandadjacent13 to the Green13 River13 Great13 Basin13 Naturalist13 56375-shy‐376

Modde T KP Burnham and E J Wick 1996 Population status of the razorback sucker13 inthe middle Green River (USA) Conservation13 biology 10 110-shy‐119

Modde13 T13 and G13 B Haines13 200513 Survival13 and growth of stocked razorback13 sucker andbonytail in multiple floodplain wetlands of the middle Green River under resetconditions13 Final report prepared for Upper Colorado13 River13 Basin RecoveryImplimentation Program US Fish and Wildlife Service Vernal 66 pp

54

13

Modde T Z H Bowen and D C Kitcheyan 2005 Spatial and temporal use of a spawning13 site in the middle Green River by wild hatchery-shy‐reared13 razorback suckers13 Transactions of the American Fisheries Society 134937-shy‐944

Mueller13 G13 199213 The native fish work13 group13 -shy‐ a multiagency endeavor to improve thestatus of the razorback sucker in Lake Mohave AZ-shy‐NV13 Proceedings of the DesertFishes Council 2369

Mueller G 1995 A program13 for maintaining the razorback sucker in Lake MohaveAmerican Fisheries Society Symposium 15127-shy‐135

Mueller13 G13 200613 Ecology of the bonytail13 and razorback13 sucker and the role of offchannelhabitats13 in their13 recovery Scientific13 investigations13 report 2006-shy‐5065 US GeologicalSurvey13 Denver

Mueller G and E Wick 1998 Testing of golf course ponds at Page Arizona for suitability13 as grow-shy‐out facility for razorback sucker using surplus fish from13 Ouray NationalFish Hatchery National Park Service US Fish and13 Wildlife13 Service and UtahDivision of Wildlife13 Resources 28 pages

Mueller13 G13 and T13 Burke13 200513 Survival13 of young13 razorback13 sucker (Xyrauchen texanus) inrelation to13 stocking rates13 (fishha)13 and13 in the presence13 or absence13 of predatorcommunities in Lake Mohave Arizona-shy‐Nevada13 Pages13 155-shy‐16313 in Proceedings of two13 symposia restoring native fish to the lower Colorado River interaction13 of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 Nevada US Fish and Wildlife13 Service Southwest Region Albuquerque New Mexico

Mueller13 G13 J13 Carpenter13 and P13 C13 Marsh13 200413 Cibola13 High Levee Pond annual report 2004US Geological Survey Fort Collins13 Science Center13 Colorado13 and Arizona StateUniversity Tempe 23 pages

Nesler T P K Christopherson J M Hudson C W McAda F Pfeifer and T E Czapla 2003An integrated stocking plan for razorback sucker bonytail and Colorado13 pikeminnow for the Upper Colorado River Endangered Fish Recovery ProgramAddendum13 to State Stocking Plans Upper Colorado River Basin Recovery13 Implementation Program 12 pp

Papoulias13 D and W13 L Minckley13 1992 Effects13 of foo availability13 on survival and growth13 of larval razorback suckers13 in ponds Transactions of the American Fisheries Society121340-shy‐355

Paukert13 C P D L Ward13 P J Sponholtz13 and K13 D Hilwig13 Effects13 of repeated hoopnetting13 on bonytail chub13 Journal of Freshwater13 Ecology13 20(4) 649-shy‐653

Pfeifer F M13 C Baker13 and M13 Montagne13 199913 Propagation13 facilities13 in the13 Grand Valley13 (24 Road13 Hatchery13 Horsethief13 Ponds and13 grow-shy‐out ponds) for captive rearing of

55

13

endangered13 fishes for the13 Upper Colorado13 River Basin13 Colorado13 River Recovery13 Program FY 99 annual project report Project No 29a13 US Fish and Wildlife Service13 Grand13 Junction13 5pp

Pfeifer F S Seversen and M Montagne 2003 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2003 annual reportProject No 29b13 US Fish and Wildlife13 Service Vernal13 4pp

Rabago-shy‐Castro J L Sanchez13 J G Perez-shy‐Castaneda R and13 Gonzalez-shy‐Gonzlez A 2006Effects of the prophylactic use of Romet-shy‐3013 and13 copper13 sulfate13 on growth13 condition13 and feeding13 indicies in13 channel13 catfish (Ictalurus punctatus) Aquaculture 253 343-shy‐349

Reinitz GL L E Orme and F N Hitzel 1979 Variations of body compositio and growth13 among strains of rainbow trout Transactions of the American Fisheries Society 108204-shy‐207

Ruppert13 J13 B P B Holden13 and P D Abate 1999 Age estimation and growth of razorbacksucker13 Xyrauchen texanus in Lake13 Mead Nevada Proceedings13 of the Desert FishesCouncil 3040

Schnoor K D and J Logan 2002 Operation and maintenance of JW Mumma nativeaquatic13 species restoration facility Colorado Colorado River Recovery Program FY2002 annual project report13 Project No 29d Colorado13 Division of Wildlife Alamosa3pp

Salisbury13 L13 1998 Factors13 affecting razorback13 sucker growth13 in Lake13 Mohave backwaters13 MS Thesis13 Unviersity13 of Nevada13 Las13 Vegas

Schooley J13 D13 and P C13 Marsh13 2007 Stocking of endangerdd13 razorback13 suckers13 in thelower Colorado River Basin13 over three decades 1974-shy‐2004 North American Journalof Fisheries Management 27 43-shy‐51

Severson S H H M Tyus and G B Haines 1992 An evaluation of feeds for raisingrazorback sucker Xyrauchen texanus Journal of Applied Aquaculture 155-shy‐65

Toney D P 1974 Observations13 on the13 propagation13 and13 rearing13 of two13 endangered species13 in a hatchery environment Proceedings of the Annual Conference of the Western13 Association of State Game and Fish Commissions 54 252-shy‐259

Tyus H M13 1998 Razorback sucker13 (Xyrauchen texanus) recovery plan13 University13 ofColorado Center for Limnology Boulder13 76 pages

Tyus H M13 and13 S H Severson 1990 Growth13 and13 survival of larval razorback suckers fedfive formulated diets The Progressive Fish Culturist 52197-shy‐200

56

13

Ulibarri M E 2003 Annual report fiscal year 2001 Dexter National Fish Hatchery13 andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 26 pages

Ulibarri M E 2003 Annual report fiscal year 2002 Dexter National Fish Hatchery andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 59 pages

USBR 2006 Lower13 Colorado13 River Multi-shy‐Species Conservation Program final fishaugmentation plan Boulder City 19 pp

USFWS 2002 Razorback sucker (Xyraouchen texanus) recovery goals Amendment andsupplement to the Razorback Sucker Recovery Plan13 US Fish and Wildlife Service13 Region 6 Denver13 Colorado

USFWS 1999 Annual report 1999 Ouray National Fish Hatchery Vernal 25pp

USFWS 2004 Management plan for the big-shy‐river13 fishes of the13 lower13 Colorado13 river basinamendment and supplement to the bonytail humpback chub Coloradopikeminnow and razorback sucker recovery plans

USFWS13 2005 Station13 profile13 of the13 Dexter13 National Fish Hatchery13 and Technology CenterUS Fish and Wildlife13 Service Dexter

Valdez R A P G Mangan R Smith and B Nilson 1982 Upper Colorado River fisheriesinvestigations13 inW H Miller J J Valentine D L Archer H M Tyus R A Valdezand L13 Kaeding13 editors13 Colorado River Fishery13 Project13 Part 2 Field13 investigations13 US Bureau of Reclamation Salt Lake City Utah

WBNFH 2004 Culture methods of the endangered razorback sucker Xyrauchen texanusUS Fish and Wildlife13 Service Willow Beach National Fish Hatchery13 8 pp

Ward D 2008 Effects of disease treatments on growth of razorback sucker ReportSubmitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 Inpartial fulfillment of work task C10 agreement number 06FG30039

Ward13 D13 M Childs and W Persons 2007 Factors13 affecting13 growth13 of razorback sucker13 (Xyrauchen texanus) in captivity Literature review and knowledge assessmentReport Submitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 In partial fulfillment of work task C10 agreement number 06FG30039

57

Appendices

Appendix 1 Survey Questions Survey of Razorback Sucker Culture in the

Southwestern United States

The enclosed survey is being distributed by the Arizona Game and Fish Department to razorback sucker culture facilities throughout

the Southwestern United States The purpose of this survey is to consolidate information regarding culture of this species so that

appropriate facility improvements can be considered for Bubbling Ponds Hatchery in Arizona Specifically we wish to increase

growth rate and production efficiency at the hatchery Information gathered in this survey will be summarized in a final report to US

Bureau of Reclamation in Boulder City NV and disseminated to all facilities that participate in the survey A workshop to discuss

the findings of this study as well as to share general information concerning razorback sucker culture will be organized by the

Arizona Game and Fish Department at the conclusion of this study and all participants will be invited

Thank you for taking the time to fill out this survey Please contact Mike Childs if you have questions or would like to discuss the

survey

Mike Childs

mchildssedonanet

(928) 639-1346

(928) 634-1279

Facility_____________________________________ Date___________________

Contact Phone _____________________________

ContactPerson_______________________________

Contact Email _______________________________

1 Water quality ranges at this culture facility

Season

Spring (Mar-May) Summer (Jun-Aug) Fall (Sept-Nov) Winter (Dec-Feb)

Temperature (C)

PH

DO (mgL)

PO4 (mgL)

TDS (mgL)

Hardness (mgL)

CaCO3

Pathogens

37

13

aggressive fish do not interfere with growth of smaller individuals but frequent handling

and sorting13 causes stress related reductions in13 growth13

Measuring Growth in Captive Fish

Weight is the traditional measure used to estimate growth or production in

aquaculture settings13 Groups of fish are typically13 weighed and an average individual13 weight13

is computed (Busacker et al 1990) Although this method is often logistically the easiest it

may not be the most informative for species with highly variable growth rates like

razorback suckers especially when target lengths must be reached before fish can be

stocked Weight can also be highly influenced by things like stomach fullness or

development of gonads (Busacker et al 1990) Condition factor or relative weight can also

be used to assess growth of fish but these tools may be more robust predictors of fecundity

than of growth (Anderson and Neuman 1996) For some species sexes need to be

distinguished because males and females may differ in morphology (Anderson and

Neumann 1996) Mueller (2006) analyzed growth rates based on PIT tag recaptures of 86

razorback suckers13 in High13 Levee Pond13 and13 found13 that differences13 in growth13 do not appear13

to occur until fish are over 450 mm TL at which time growth rate in males slows while

females continue to grow at a slightly higher rate This would indicate that sex may not be

an important factor to consider when examining growth rates unless the target grow-shy‐out

size is above 450 mm TL

The best measures of growth are often determined from13 the length and weight of

individuals rather than from13 groups of fish (Anderson and Nuemannn 1996) because

individual growth rates give better estimates of confidence and variance (Busacker et13 al

1990) Length frequency analysis or recapture of previously marked individuals of a known

size is likely to yield the most useful information for razorback sucker growth The success

of any of these methods depends on proper sampling procedures that are representative of

the population as a whole (Busacker et al 1990) Sampling methods that are known to be

size-shy‐biased such as trammel nets (Mueller et al 2004) or cast nets should not be used when

trying to measure growth rates13

26

13

Conclusions

For razorback sucker survival is largely associated with stocking size Additional

focused13 research13 is therefore13 needed to13 identify13 ways13 to13 increase13 growth13 rates13 of captive-shy‐

reared13 razorback sucker Growth13 rate13 in fish is controlled13 by many factors including fish

size and age temperature density and feed ration which can all be highly correlated

Growth of razorback suckers is also inherently variable which makes the task of identifying

the key factors that13 affect13 growth in13 captivity even more difficult The focus at most

razorback rearing facilities13 is production so the13 types13 of data that are13 collected13 are13 often

insufficient for detailed13 evaluations13 of individual rearing13 practices13 on growth13 Surveys of

existing13 razorback sucker13 rearing facilities indicate that culture methods vary widely and

the types of growth data13 that13 are collected are not13 standardized13 Replicated studies with

detailed information on rearing location water temperature initial stocking size stocking

density and the sizes of all fish at harvest are needed in order to compare the effects of

individual rearing practices on growth This type of research will ultimately provide both

time and cost-shy‐savings to production facilities by reducing the amount of time necessary13 for

razorback sucker to reach stocking size improving overall production efficiency

Optimum13 rearing densities for razorback sucker larvae and juveniles remain to be

determined Current stocking densities will be very useful as starting point for more

detailed studies and although optimum13 rearing densities are likely to be site-shy‐specific13

replicated studies on density will provide a valuable reference for hatchery managers

Frequency13 of sorting is another13 area that needs13 further13 research Frequent

handling13 and13 sorting13 can13 cause13 stress-shy‐related13 reductions13 in growth but not sorting can

create dominance hierarchies that further reduce growth rates of subordinate individuals

The effects13 of sorting13 on overall fish growth13 in both13 pond and13 intensive13 culture13

environments warrant further investigation Research techniques for these types of

experiments are well understood and typically utilize a matrix of replicate ponds per

variable (Bays et al 2005) In every case accurate and complete records of sampling

procedures and data collection are needed in order to interpret data and make inferences

about13 growth rates (Busacker et13 al 1990)13

27

13

Additional research is also needed to evaluate long-shy‐term13 survival of stocked fish

reared in ponds compared to fish13 reared13 in intensive13 culture13 facilities13 Exercise13

conditioning13 and predator-shy‐recognition training may also increase survival of stocked fish

and be more economically feasible than rearing fish to increasingly larger sizes prior to

stocking13 The success13 of traditional fish hatchery programs is measured largely by the

number of fish stocked but hatchery programs for endangered species must measure

success in terms of long-shy‐term13 survival and species recovery (Brannon 1993 Anders 1998)

A specific list of research recommendations follows

Specific Research13 Recommendations13

bull Use replicated studies13 to establish optimum stocking13 densities13 for ponds13 and

tanks13 that can be used as13 a starting13 point for site specific refinement

bull Determine if sortinggrading13 improves13 overall growth rates13 in both ponds13 and

intensive culture facilities13

bull Investigate the use of artificial fertilizers13 to improve growth of both juvenile

and adult razorback suckers13 in ponds13

bull Determine if the razorback sucker diet gives13 better growth rates13 than cheaper

catfish or salmon feeds

bull Evaluate growth rates13 and production potential of new intensive culture

methods13 such as13 large circular tanks13

bull Evaluate13 long-shy‐term survival of fish produced from raceways13 and circular tanks13

compared to fish reared in ponds13

bull Evaluate more effective means13 of treating13 fish diseases13

bull Evaluate factors13 other than size that may increase post-shy‐stocking13 survival such

as13 exercise conditioning13 predator recognition training or rearing13 under more

natural settings13

28

13

II The Effect of Disease Treatments on Razorback Sucker

Growth

Section13 SummaryFormalin copper sulfate potassium permanganate and13 salt are all chemicals commonly13 used13 to13 treat13 Ichthyophthirius multifiliis outbreaks in captive razorback sucker (Xyrauchen13 texanus) Weexposed 190 juvenile13 razorback suckers (127 ndash 26 mm TL) to13 5 5-shy‐day treatments with13 each13 chemical to evaluate the effects13 these chemicals13 may have on growth Fish grew an average of23513 mm TL13 during the month13 study period Fish treated with formalin grew on average13 29mm TL (03 mmday) while fish treated with copper had the lowest growth averaging 20 mmTL (021 mmday) No significant differences in13 growth were observed among fish treatedwith any of the chemicals compared to untreated fish (pgt005) Reductions in growth13 as aresult of repeated chemical treatments are not likely the cause of differences in growth ratesamong13 facilities that raise razorback suckers Repeated chemical treatments may13 have otherimpacts to overall13 fitness or long-shy‐term survival but13 these effects were not13 evident13 in our study

29

13

Introduction

Preservation13 of razorback sucker13 (Xyrauchen texanus) currently13 depends on captive13

rearing and stocking programs until permanent solutions to factors that prevent wild13

recruitment are found Low survival of stocked razorback suckers (Brooks 1986 Marsh

and Brooks 198913 Marsh and Pacey13 2005) has caused target13 sizes for stocked fish to

steadily increase in efforts to reduce predation mortality (Marsh et al 2005 Schooley and

Marsh 2007) Rearing fish to larger sizes at hatcheries comes with increased costs and

creates the need to evaluate husbandry and rearing practices that may affect fish growth

Formalin copper sulfate potassium13 permanganate and salt are all chemicals

commonly used at razorback sucker rearing facilities to treat outbreaks of the protozoan

parasite13 Ichthyophthirius multifiliis ldquoIchrdquo is one of the most pathenogenic diseases of

cultured13 freshwater13 fishes (Matthews13 2005) and causes large13 losses in captive13 populations13

of endangered razorback sucker Each of these chemicals used to treat Ich only kill the free-shy‐

swimming life stage of the parasite13 requiring13 repeated doses over several13 days depending13

on water temperature These chemicals treatments are needed to prevent loss as a result

of disease outbreaks but the cumulative effects repeated disease treatments have on

growth13 are13 unknown

Copper13 sulfate13 has13 been shown to13 significantly13 reduce13 growth13 of channel catfish13 in

production13 ponds (Rabago-shy‐Castro13 2006) but it is unknown whether13 razorback suckers13

experience similar reduced growth following copper treatment Quantifying the impacts of

disease treatments on growth will help to interpret the wide differences in growth rates

observed13 at various13 razorback sucker13 production13 facilities13 throughout the13 southwest

(Ward et al 2007) If one chemical is found to have less detrimental impacts on growth

than another then it may be preferred for use as a disease treatment We evaluated growth

rates13 of razorback suckers13 under13 replicated13 and13 controlled13 conditions13 to13 assess13 effects13 of

repeated formalin copper sulfate and potassium permanganate and salt treatments on

growth13

Methods

We captured 190 juvenile razorback suckers from13 ponds at Bubbling Ponds Fish

Hatchery AZ using hoop nets or cast nets All fish were of the same age class and

30

13

averaged 179 mm total length (TL) (range13 = 127 ndash 262 mm TL)13 These fish were13 offspring13

of captive13 razorback sucker13 broodstock held13 at Dexter13 National13 Fish Hatchery13 NM13 (2007

year class) All fish were tagged with passive integrated transponder (PIT) tags and

quarantined for one month prior to the experiment to allow fish to recover from13 tagging

and become accustomed to being held in circular tanks

At the beginning of the study all fish were weighed measured and scanned for

individual tag numbers with 19 randomly selected fish placed into each13 of 10 8-shy‐foot

diameter circular tanks (Figure 2)13 Each13 tank contained13 two13 airstones13 and13 an13 individual

biofilter with a recirculating water pump (31 litersminute) that had been operating for

at least 1 month prior to the experiment to allow bacterial colonies to become

established Two tanks were designated as a control and did not receive any chemical

treatments while the other eight tanks received formalin copper sulfate potassium13

permanganate or salt treatments at two week intervals (two tanks per chemical

treatment) Formalin copper sulfate and potassium13 permanganate were treated at 1 part

per million (ppm) and salt was applied at 30 parts per thousand (ppt) These treatment

rates are commonly used to treat13 razorback13 suckers for ich at Bubbling13 Ponds Fish13

hatchery (Frank Agygos personal communication)

Figure 213 Photo ofexperimental tankswith individualbiofilters and aeration

31

13

Each treatment consisted of a series of doses applied on Wednesday Thursday and

Friday with a 90water change between each dose Biofilters were removed from13 all

tanks and held in a separate holding facility during treatments and then replaced on the

Monday following treatments after a 90water change This schedule allowed fish to be

exposed to chemical treatments for 5 consecutive days without water quality deteriorating

This 5-shy‐day chemical treatment was repeated every two weeks from13 July to October (97

days)13 for a total of 5 5-shy‐day treatments Water temperature in the treatment tanks ranged

from13 13degC (55degF) to 32degC (91degF)

Fish were fed a fixed ration of commercial razorback diet (Silvercup 4mm13 pellet)

once daily13 (2 percent body13 weight per day13 as calculated13 by13 average initial fish weight)13

At the end of the experiment all fish were again weighed measured and scanned for

individual tag numbers Growth of fish in each treatment group was compared using

analysis of variance (ANOVA) Any mortalities13 that occurred during the13 study13 were13

replaced with previously quarantined fish of equivalent size to maintain equal densities in

each13 tank13 but growth13 data was13 only13 recorded for fish which13 survived13 the13 entire13

experiment

Results

Fish at the13 start of the experiment averaged 179 mm TL (Range13 = 127 ndash 262 mm)

with no significant differences in fish length among treatment groups (F(4189) = 00183 p

gt 0999 ANOVA) On average fish grew 235 mm TL (024 mmday) during the 3 month

study13 Fish in tanks13 treated with formalin had the highest growth averaging 29 mm TL (03

mmday) while fish in tanks treated with copper had the lowest growth averaging 20 mm

TL (021 mmday) Fish in the control tanks averaged 213 mm TL in growth (022

mmday) (Figure13 3)13 Formalin-shy‐treated fish grew13 significantly faster than13 any other

treatment group but no13 significant differences in growth13 in length13 or weight were13

observed among fish treated with any of the chemicals compared to untreated (control)

fish (pgt005 ANOVA)

32

13

Figure 313 Average growthof razorback suckersexposed to a series of 5 5-shy‐day chemical treatmentsover a 97-shy‐day13 periodError bars representstandard error

Discussion13

Growth13 rates13 observed13 in our study13 (021 ndash 03 mmday) are low compared to those

reported13 in other13 studies13 of razorback sucker13 growth13 (0213 ndash 18 mmday) (Ward et al

2007) Using recirculating water systems for our study required filters to be removed and

replaced during treatments Stress to fish caused by removing and replacing filters within

the tanks as well as repeated water changes may have led to overall higher stress and

reduced growth rates compared to those reported for unconfined fish Growth in fish is

highly variable and is affected by many different physiological and environmental factors

including fish size density temperature amount of space and food (Brett 1979) We

strived to control each of these factors but other factors may have also influenced growth

in our experimental tanks During mid-shy‐summer water temperatures in the treatment

tanks reached 32degC (91degF) At these warm13 temperatures fish are very susceptible to

bacterial13 infections13 The slightly higher growth exhibited by fish in the formalin and

potassium13 permanganate treatments may have been the result of these two chemicals

33

13

being effective at controlling bacterial infections The differences in growth we measured

among treatment groups were not statistically significant and do not appear13 biologically13

meaningful during the relatively short duration of this study (97 days) although the

cumulative effects of slightly reduced growth could be biologically meaningful over longer

time frames

Reductions in growth13 as a result13 o repeated chemical treatments are not likely the

cause of differences in growth rates among facilities that raise razorback suckers

Repeated chemical treatments may have other impacts to overall fitness or long-shy‐term13

survival but these13 effects13 were13 not evident in our study It is more likely that the parasite

outbreaks themselves are the cause of different growth rates among razorback rearing

facilities rather than the chemical treatments used to treat the parasites We recommend

that hatchery managers continue to use the chemicals that are most effective at controlling

ldquoIchrdquo13 at their individual13 facilities

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower Colorado Rive Multi-shy‐species13

Conservation Plan under Work Task C10 We thank Ty Wolters and Tom13 Burke for their

support of this research and Frank Agygos and Dave Billingsly of the Bubbling Ponds Fish

Hatchery13 for their13 technical assistance13 and13 help with13 collecting13 fish

34

13

III13 Razorback Growth Rates at Bubbling Ponds ndash 2009-shy‐2011

Section13 SummaryExperimental studies at Bubbling Ponds Fish Hatchery AZ have strived to understand

factors that affect razorback sucker growth in captivity and identify ways to improve growthrates and maximize size at release Rather than performing experimental studies that wouldrequire major13 rearrangement (and likely reduced production)13 of hatchery operations our13 studies13 used normal variation in production techniques13 and practices13 to isolate factors13 thatmay modify growth rates

Our initial work identified razorback13 growth rates in13 lined ponds at standard fishdensity as 026 to13 028mmday (789 to 843 mmmonth) No significant differences in growthrate were observed among fish that had been in the pond only during the winter13 periodcompared to fish that had been in the pond the entire year indicating that water temperatures13 at Bubbling Ponds are high enough to allow fish to incorporate feed effectively year-shy‐roundHowever these growth rates are lower than most values reported from the literature fromnatural or semi-shy‐natural pond environments No significant differences in13 growth rate wereobserved13 between large and13 small fish13 within the 150 ndash 29 mm TL13 size range Additional worksuggests13 that razorback suckers13 tagged at over 300 mm TL had reduced growth rates (024mmday 73 mmmonth) as would be expected according to a typical Von13 Bertalanfy growthcurve although growth rates13 were only slightly less13 than the average growth rate for thehatchery (027513 mmday 82513 mmmonth)

Sorting13 to13 separate small fish from large fish after the first year of growth is practicedesigned13 to allow smaller fish to ldquocatch uprdquo to larger fish We found that13 this technique doesappear to13 improve growth rates of smaller fish Growth rates of sorted small razorback suckers(029 mmday 87mmmonth)13 were equal to that13 of larger13 fish (028 mmday 8413 mmmonth)indicating that sorting may have helped to offset their original slower growth trajectory

Bubbling Ponds Fish Hatchery grows razorbacks in 6 long deep ponds lined with heavyplastic 2 long deep13 earthen13 (unlined) ponds and three wide shallow earthen ponds The wideshallow ponds13 have historically produced very large fish at low density but have been found tomaintain much lower fish numbers than deeper ponds We found13 that growth13 rates ofrazorbacks kept at high density (4-shy‐700013 fish)13 in a wide shallow pond grew extremely slowly(024 mmday 726 mmmonth) This growth rate is among the slowest of any fish over theyears of our study and demonstrates that13 though the large ponds may produce large fish at lowdensity13 they are unable to overcome high13 fish13 densities

Finally one of the major factors influencing13 fish13 growth13 in hatcheries is disease onemajor summer-shy‐time disease at13 Bubbling Ponds is the ectoparasite Ich (Ichthiopthirusmultifiliis) To investigate the impact Ich has on razorback growth we eradicated fish from thespring and water conveyance ditch that supplies13 water to the hatchery using Rotenone This13 restoration effort was fairly short-shy‐lived (Ich returned to the hatchery within four months) but

35

13

growth13 rates of fish13 reared for four months without Ich present (031 mmday 92 mmmonth)were significantly higher than the following 8 months of growth for those same fish (022mmday 65 mmmonth) This disease-shy‐free growth rate is in fact faster than any13 otherprevious growth rates observed at the hatchery in our study

We conclude that growth rates at the Bubbling Ponds Fish Hatchery are likely as highas possible given the pond densities required to13 meet production goals and the Ich-shy‐infestedwater13 that feeds the facility Sorting practices are successful in helping as many fish as possiblereach stocking length as fast as possible Unlined ponds may be able to grow large fish at lowdensities but whatever factors allow for that growth13 are not able13 to overcome13 high fish densityThus the large lower ponds at Bubbling Ponds may be better utilized via renovation to13 deepenand line them

Disease is the most important factor limiting growth as may be expected to be the caseat many13 hatcheries While the spring renovation was not13 a complete success13 the dramaticreduction of fish populations in that habitat was enough to dramatically13 reduce13 the13 occurrenceof Ich at the hatchery13 Such open spring13 systems feeding a hatchery are a misfortune that canbe expected to transmit disease so we suggest that renovating the spring again to combat13 IchImproved techniques to divert water from13 the springs and more throuough treatment ofstream-shy‐side vegetation may improve the success of chemical treatment Successful renovationwould likely both improve growth rates and reduce chemical costs associated with treating Ichoutbreaks Even13 if complete renovation13 is impossible or impractical an13 effort to reduceinvasive fish density in the springs13 which act a vector for the parasite(and thereby reduce thelikelihood of13 Ich being transmitted into ponds) may still13 show dramatic improvements

36

13

Introduction

Conservation efforts13 for razorback sucker13 (Xyrauchen texanus)13 currently13 depend on

captive rearing and stocking programs Low survival of stocked razorback suckers (Brooks

1986 Marsh13 and13 Brooks13 1989 Marsh13 and13 Pacey13 2005) has13 caused13 target sizes for stocked13

fish to steadily increase in efforts to reduce predation mortality13 (Marsh13 et al13 2005

Schooley and Marsh 2007) Rearing fish to larger sizes at hatcheries comes with increased

costs and creates the need to evaluate husbandry and rearing practices that may affect fish

growth13 We evaluated growth13 rates13 of individual razorback suckers13 in ponds13 at Bubbling

Ponds Fish Hatchery13 using Passive Integrated13 Transponder (PIT) tags13 to13 obtain13 precise

growth information for individual fish so that valid comparisons of growth rates as related

to rearing practices can be made

Due to the critical nature of the razorback sucker stocking program we did not

design experimental studies that would require major rearrangement and potentially

reduce production of hatchery operations Instead our studies used normal variation in

production techniques and practices to isolate factors that may modify growth rates

Though this methodology dramatically limits replication and may limit our ability to

directly13 attribute13 differences in growth13 rates13 to13 the13 variables13 we13 investigate13 we13 were13 able13

to accomplish research goals without altering hatchery operations or impacting

production

From13 2009 through 2011 we conducted a series of observational13 growth13 studies to

determine growth rates of individual razorbacks at Bubbling Ponds The first set of

experiments included13 identifying13 growth13 rates13 in lined13 and13 unlined13 ponds determining

growth13 rates13 of fish at different13 sizes13 in13 relation13 to sorting13 practices and monitoring

razorback growth rates after removing the source of the ectoparasite13 Ich (Ichthiopthirus

multifiliis) from13 the hatchery water source13

Razorback growth rate in lined ponds

Our first growth study documented individual growth rates at normal density in 11

million gallon lined ponds13 over two13 years13 This is the standard13 grow-shy‐out process for

razorbacks13 at Bubbling Ponds We monitored growth of fish for a variety13 of sizes and13 the13

37

13

amount of time in a pond during the growing season These13 data give a snapshot of growth13

rates13 at the13 facility13 and13 provide13 the basis for comparisons throughout our study

Growth rate13 in an unlined pond

In addition13 to 6 ponds lined with heavy plastic13 sheeting13 Bubbling Ponds Fish13

Hatchery maintains two narrow and deep (same dimensions as lined ponds13 Figure13 4)13 and13

three large13 shallow unlined ponds These earthen13 ponds typically have vegetation and

associated aquatic invertebrates that may better simulate natural environments by

providing cover and improved food diversity or quality Therefore these unlined ponds

may be expected to produce higher growth rates and potentially improved survival that is

more similar to growth rates observed in more natural grow-shy‐out facilities13 Historically13 the13

large13 shallow13 ponds have produced very large fish when13 utilized at low13 fish density13 The

narrow13 deep earthen13 ponds are13 used to grow13 fry13 at high density in their first13 year of life

The major downside to unlined ponds is the difficulty in harvesting fish where a lined

pond might take 8-shy‐1013 people13 a half13 day13 to13 harvest13 lined13 ponds13 require13 intensive13 weeding13

to allow seines to be pulled and therefore require many more personnel-shy‐hours13 In addition13

to harvest challenges the shallow earthen ponds tend to suffer from13 dissolved oxygen

crashes during the summer Unlined ponds also may maintain higher13 populations13 of non-shy‐

target species such as bluegill sunfish mosquito fish and bullfrog tadpoles We measured

growth rates of suckers in a large shallow earthen pond for comparison to growth in lined

ponds13

Figure13 4 Lined13 and13 earthen ponds13 of similar dimensions (approx 1000000 gallons first

and second panels) and a large13 shallow13 earthen13 pond (third panel)

38

13

Effect of sorting on growth

Razorback13 suckers13 are13 currently13 sorted13 after their first13 year of growth13 They are13

typically removed from13 one of the13 upper earthen13 ponds and13 split into13 two13 lined13 ponds for

subsequent grow-shy‐out13 The larger13 fish (gt approximately 140 mm) are placed into one pond

and the smaller individuals in another It is possible that the larger fish were more

aggressive or adept13 at taking food so this sorting process is intended to allow smaller fish

to improve their growth rate

Effect of Ich on razorback sucker growth rates

We13 evaluated13 growth13 rates13 of razorback sucker13 in the13 presence13 and absence of the

ectoparasite13 Ich (Ichthiopthirus multifiliis) Ich outbreaks can occur in wild populations13 but

hatcheries13 have13 proven excellent locations13 for Ich because13 of very high fish densities13 which13

facilitate13 the13 transfer13 of Ich13 between13 fish This common fish parasite causes direct mortality13

to razorback13 suckers as well13 as secondary bacterial13 infections13

The open spring and13 ditch13 which13 provides water to the Bubbling13 Ponds Hatchery

has long13 been infested with mosquitofish (Gambusia affinis) that harbor13 the13 Ich parasite13

and allow13 it13 to enter the hatchery with incoming13 water13 The solution13 to13 the13 Ich problem13

was to remove the mosquitofish host using13 Rotenone Razorback13 sucker growth13 rates were13

then tracked in13 the absence of this parasite for 4 months and compared with growth rates

after Ich returned to the pond and from13 previous years

Methods

Razorback growth rate in lined ponds

On May 14 2008 141 razorback suckers were tagged with 12 mm PIT tags (1342

kHz) and placed in Pond 3 (approximately 1100000 gallons13 Figure13 4)13 at Bubbling13 Ponds

Fish Hatchery Fifty-shy‐three of these tags were recovered two months later when a large

Ichthyophthirius multifilis (Ich) outbreak killed many fish in the pond On October 15 2008

an additional13 145 PIT tagged13 fish were13 also placed into Pond13 3 On13 May13 14 2009 Pond13 3

was harvested and a total13 of 141 PIT tagged fish were recovered13 Of the tagged fish13 26 fish

had13 been13 in the13 pond since May13 of 2008 (378 days13 o growth) and 115 had been13 in13 the

39

13 40

pond since October13 15 2008 (211 days13 of growth) Numbers of fish in Pond 3 after the Ich

outbreak and for the majority of the period of growth were between 3 000 and 4000 fish

A Hobotempreg temperature13 logger13 was13 also13 installed13 in Pond 3 one meter below the water

surface13 near13 the13 outflow and13 recorded water temperature every 3 hours to allow analysis

of the effects of water temperature on growth rate (Figure13 5) This Hobotemp data is

representative of other pond temperatures throughout this study

In a second experiment 210 adult13 razorback suckers13 were13 PIT tagged13 on13 May 14

2009 and13 placed13 into13 Pond13 3 upper to13 evaluate13 growth13 rates13 of larger13 razorback suckers13 at

Bubbling13 Ponds Hatchery13 under current13 rearing13 conditions13 Size of these fish at tagging13

was (mean = 285 mm range = 205 ndash 396 mm) These fish remained in the pond for 257

days and were harvested on Jan 25 2010 to provide information on growth rates of larger

razorback suckers13 under13 current rearing conditions

Figure 513 Temperatures (degC) inrearing pond at BubblingPonds Hatchery from July toSept 2009 (top graph)13 andfrom Nov to Dec 2009 (Lowergraph) Temperaturesrecorded with a Hobotempregremote data logger13 every 3hours

13

Growth rate13 in an unlined pond

To document razorback sucker growth in earthen ponds we introduced13 225 tagged13

razorback suckers13 into13 Pond13 1 lower13 (Figure 4) in February 3 2010 Additional tagged fish

from13 other studies were added to the pond throughout the growing season and the density

of 1 lower reached a maximum13 of nearly 7000 fish in early summer 2010 Density was

reduced to approximately 6000 fish by capturing fish with hoop nets on June 3 2010 54 of

these fish were tagged fish and returned to 1 lower after being weighed and measured The

pond was harvested on January13 2713 2011 and a total13 of 254 tagged fish out13 of 4296 fish

total were removed from13 the pond The pond was harvested on January 27 2011 (358 days13

of growth) and the tagged fish were weighed and measured Total number of razorbacks in

the pond at harvest13 was 4296

Effect of sorting practices on growth rates

On March 1113 200913 Pond13 5 upper was13 harvested13 and13 split into13 two13 separate13 groups

Two hundred of the smaller fish (average size = 122 mm TL) were PIT tagged and placed

into13 Pond13 7 upper and13 200 of the13 larger13 fish (average = 160 mm TL) were PIT tagged and

placed int Pond13 8 upper Density13 in Pond13 7 was13 4500 fish and13 in Pond13 8 there13 were13 6500

fish These ponds were then harvested after 1 year and growth rates were compared to

give information on the effects of current sorting practices Hobotempreg temperature

loggers were installed in13 Ponds 7 and13 8 during13 the13 grow-shy‐out period with13 water13

temperature recorded every 2 hours13 (Figure13 6)

Effect of Ich on razorback sucker growth rates

Bubbling Ponds spring was treated with Rotenone (CFT Legumine 5) at a

concentration of 2 ppm13 to remove all mosquitofish from13 the spring The treatment

consisted of two treatments 6 hours in duration on two consecutive days (April 12 -shy‐ 13)

using13 drip13 stations13 and13 backpack sprayers13 followed13 by13 an13 additional 6 hours13 of

detoxification using sodium13 permanganate Although 12 mosquitofish were captured in the

spring pond the week following the treatments subsequent minnow trapping (20 traps

checked13 daily13 for 3 weeks) did not capture any additional fish until August 11 2010 when

41

13

juvenile mosquitofish were again detected in the spring pond Minnow traps have

subsequently been set daily with several hundred individuals removed To evaluate if Ich

was also again present in the spring we captured 15 mosquitofish from13 the spring pond on

three separate days and placed them13 in an aquaria at 25 degC with 5 longfin dace known to be

free of Ich These fish were monitored for 2 weeks with no signs of Ich developing This

indicates that even though mosquitofish have returned to the spring pond the parasite is no

longer present13 although how13 long13 this condition13 will13 persist13 is unknown13

On May 1113 201013 200 juvenile razorback13 suckers were harvested out13 of Pond 5

upper (2009 year Class from13 Dexter National Fish Hatchery) and were PIT tagged and

placed into Pond 8 to evaluate if growth rates at bubbling ponds hatchery have improved

following the renovation of the spring and the removal of the Ich parasite Unfortunately13

on Sept13 8 2010 Ich was13 again13 detected13 in Pond 8 and the pond was immediately seined

and 74 tagged fish were measured to obtain growth information for the 4-shy‐month period

during13 which13 the13 pond13 was13 Ich-shy‐free13

Figure13 6 Temperatures (degC) in rearingponds 7 and 8 at Bubbling Ponds Hatchery13 from March 2009 ndash March 201013 pond 7(top13 graph)13 and13 pond 8 (Lower13 graph)13 Temperatures recorded with a Hobotempregremote data logger every 3 hours

42

13

Results

Growth in Lined Ponds

Razorback suckers13 that had been13 in13 Pond 8 upper for the13 entire13 year13 grew an13

average of 0263 mmday (789 mmmonth) and razorback suckers that had been in the

pond for 7 months (Oct -shy‐ May) grew13 on13 average of 028 mmday (843 mmmonth) (Figure13

7) These growth13 rates13 did not significantly13 differ Fish density13 in Pond 3 during13 the13

majority of the growth period was13 00032 ndash 00036 fishgallon13 Additionally no13 significant

differences in growth rate were observed between fish smaller than 210 mm TL and fish

larger than 210 mm TL when all recaptured fish were combined

We also measured the growth rate of very large fish in a lined pond On Jan13 2513 201013

156 adult fish with PIT tags were recovered from13 Pond 3 upper13 These fish were13 in the13

pond for 257 days and experienced an average13 growth13 rate13 of 024mmday or 73

mmmonth (Figure13 7)13 This growth13 rate13 is slightly13 lower13 than13 the13 average13 growth13 rate13

observed13 at Bubbling13 Ponds Hatchery in other studies (0275 mmday 825 mmmonth)

but may not be biologically meaningful We would expect larger13 fish to13 have13 reduced

growth rates according to a typical Von Bertalanfy growth model (Bertalanffy 1957) but it

appears that13 over the size range we evaluated (300 -shy‐ 450 mm TL) growth rates have not

slowed significantly compared to that of smaller13 fish grown at Bubbling Ponds13 Hatchery

Growth13 of razorback suckers13 is known13 to13 slow as13 fish reach13 larger13 sizes but it appears13 this13

reduced growth rate may not really start to be biologically meaningful at Bubbling Ponds

Hatchery13 until razorback suckers13 exceed 450 mm TL

Growth in unlined ponds

Growth13 rates13 for the13 fish recaptured13 during13 the Pond 1 lower13 thinning13 (120 days13 in

the pond) was 024 plusmn 003 mmday (729 plusmn 090 mmmonth) (Figure13 8)13 Fish13 that were13 in

the pond for nearly the entire year grew13 an13 average13 of 024 plusmn 001 mmday (726 plusmn 027

mmmonth) These growth rates are surprisingly the lowest measured growth rates for

any part of our study and differ significantly from13 every other measured growth rate

except very large13 fish (Figure13 9)13 Separating13 out13 large fish that13 were in13 the pond for the

entire year makes no difference fish that were added to the pond at TL lt300 mm grew

43

13

Gro

wth

Rat

e (m

md

ay)

020

026

032

0244 plusmn 001 mmday (733 plusmn 028 mmmonth) and and those with TL gt= 300 mm at the

start of the experiment grew 022 plusmn 003 mmday (651 plusmn 101 mmmonth)

Razorback Growth Rates in Lined Ponds

Figure 7 Growth ofrazorback suckers in(mmday plusmn standard error)in Pond 8 upper in 2008-shy‐2009 An ANOVA did notdetect any significantdifferences

7 Months Full Year 300+ mm fish

Effects of sorting on growth

One hundred and seventy five tagged razorback suckers were recovered from13 Pond

8 upper13 on March13 24 2010 (378 days13 of growth)13 These were13 the13 larger sorted13 fish (gt140

mm TL) that came out of Pond13 5 on March13 11 2009 One13 hundred and13 twenty13 two13 tagged13

razorback suckers were also recovered from13 Pond13 7 upper on March13 31 2010 (385 days13 of

growth)13 These were13 the13 smaller sorted13 fish (lt140 mm TL) that came out of Pond13 5 on

March 1113 200913 No significant differences in growth rate (mmday) were observed among

larger fish in Pond 8 and smaller fish in Pond 7 (pgt005 ANOVA) (Figure 10)13 indicating

that13 sorting may have helped to offset the original slower growth trajectory of the smaller

fish Temperatures of Ponds 7 and 8 upper remained similar throughout the year13 (Figure

5)

44

13

13

13

Gro

wth

Rat

e (m

md

ay)

Gro

wth

Rat

e (m

md

ay)

020

026

032

020

026

032

Razorback Growth in an Unlined Pond

Figure 8 Growth of razorbacksuckers (mmday plusmn standard error) in Pond 1 lower (an unlined pond)in 2010-shy‐2011 An ANOVA did notdetect any significant differences

6 Months 12 Months lt 300 mm Fish 300+ mm Fish Growth Growth

Lined vs Earthen Ponds 1 year of growth

Figure 9 Growth of razorbacksuckers (mmday plusmn standard error) in lined and unlined ponds A t-shy‐test13 did not detect a significantdifference

Lined Pond Unlined Pond 1 Yr Growth 1 Yr Growth

45

13

Effect of Sorting G

row

th R

ate

(mm

day

) G

row

th R

ate

(mm

day

)

032

020

026

032

020

026

Smaller Fish Larger Fish

Effect of Ich

Figure 10 Average growthof razorback suckers(mmday plusmn standard error)that were size-shy‐sorted intosmall fish (pond 7) and largefish (pond 8) populations At-shy‐test did not detect asignificant difference

Figure 11 Average growth ofrazorback suckers (mmday plusmnstandard error) after Ich wasremovd from the hatcheryrsquos springand after Ich was again detected inthe pond The growth rate withoutIch is significantly higher than boththe rate after Ich and the ourstudyrsquos average annual growth ratein lined ponds (ANOVA p =00003)

Growth without Ich Growth With Ich Average Annual 4 months 4 months Growth Rate

46

13

Effect of Ich on razorback sucker growth rates

Seventy-shy‐four13 tagged13 razorback suckers13 were13 recovered from13 Pond 8 on September

15 2010 These fish had13 been13 in the pond for 4 months and experienced a growth rate of

032 mmday or 97 mmmonth (Figure13 11)13 This growth13 rate13 is significantly higher (p =

005 two sample t-shy‐test) than the mean growth rate for the same group13 of tagged fish after

Ich detection (022 mmday or 65 mmmonth) and significantly higher than any other

individual growth13 rates13 observed13 to13 date13 at Bubbling13 Ponds Hatchery13 (Figure13 11)13 If this13

growth13 rate13 were13 extended throughout13 the entire13 year13 fish on average from13 Ich-shy‐free13 ponds13

would be 16 mm longer than fish from13 ponds infested with Ich Studies conducted at

Bubbling Ponds hatchery in 2008 (Ward 2008) did not reveal any effects of the treatment

chemicals on razorback sucker growth rates so it13 is likely that13 the parasite outbreaks

themselves are causing reducing growth rates rather than the chemicals used to treat the

parasites13

Conclusions

Our results suggest that under typical hatchery operations (maximizing number of

fish produced)13 the growth13 rate13 of razorback13 suckers13 is relatively13 consistent at Bubbling13

Ponds hatchery13 at 02-shy‐03 mmday (6-shy‐9 mmmonth)13 but is lower than growth13 rates13 at

other13 facilities (02 ndash 18 mmday Ward et al 2007)13 This growth13 rate13 has13 been13 constant in

both lined and unlined ponds and at all fish densities we were able to measure To achieve13

growth13 rates13 substantially higher than this will likely require13 significant changes in rearing

practices that may not be practical in order to reach numerical production13 goals

Temperature is a key variable in fish growth but seasonal growth patterns

described13 above13 (Figure13 5) demonstrate that water temperatures are high enough in

winter to maintain razorback growth Differences in water temperature by season

currently13 do not fluctuate more than 10degC at Bubbling Ponds because of the continuous

supply of water flowing through each pond (approx 225 gallonsmin) These high water

flows appear to keep pond temperatures within the thermal preference13 for razorback

suckers13 (1213 -shy‐ 28 degC Bulkley and Pimentel 1983) throughout the entire year with

temperatures rarely dropping13 below 16deg13 C (Figures 513 6)13

47

13

Fish density is another key variable in fish growth and though the number of fish in

a pond during our study ranged from13 3000 to 700013 fish we13 did not find any13 correlation13

between13 density and growth rate13 This might yield two conclusions First13 razorback

growth13 may be changed equally13 by13 densities13 at the13 hatchery13 (ie13 a density13 of 3000 fish in a

pond is as stressful13 for razorbacks as a density13 of 7000 fish) An alternative is that other

factors13 such as disease outbreaks have13 stronger13 control over fish growth13 than13 density13

Fish density13 would13 have13 to13 be13 experimentally manipulated to test13 this13 and hatchery

operations (producing the maximum13 number of fish) prevented our manipulating density13

in ponds for this13 work The trouble with manipulating density demonstrates the difficulties

associated with changing13 hatchery13 practices experimenting with density would have

prevented BPH from13 meeting13 production13 goals Given that the stocking of smaller

razorbacks has met with very little success perhaps BPH goals could be changed from13

producing 12000 fish at 300+ mm per year to a smaller number of very large fish each

year Growing13 fewer13 larger13 fish could potentially be accomplished in the same time frame

as more smaller fish but a better understanding of how density alters growth rate would

be required to be confident13 of this

The very slow growth13 in the13 earthen13 unlined13 Pond 1 lower13 was very surprising We13

had13 anticipated13 that the13 diversified diet13 cover and13 other13 habitat features13 provided by13

unlined ponds would yield dramatically increased growth rates However these traits were

not enough to offset high fish densities and in fact the unlined pond in our study13 suffered

mortality to bring densities down to that observed normally in lined ponds

Our data13 suggest13 that razorbacks13 sucker13 growth13 rates13 are13 higher in lined13 ponds13

However we13 think the reasons13 for the13 very slow growth we observed13 in the13 unlined13 pond13

in our study13 is instead13 linked13 to13 the13 usage13 of Pond 1 lower13 during13 the13 study13 rather13 than13

intrinsic13 slow growth13 in earthen13 ponds First the pond was at extremely high density for at

least part of the study The volume of Pond 1 lower has not been estimated but hatchery

managers suggest 1500-shy‐2000 fish is an appropriate number of individuals so this pond

was at a very high density for much of the experiment Second dissolved oxygen is often

very low in the13 large13 earthen13 ponds during the heat of summer much lower than that of

lined ponds This will both limit the number of fish that can survive in the pond and almost

certainly13 increases stress13 of these13 fish potentially13 reducing growth13 The DO crashes also13

48

13

limit the amount of feed hatchery managers can give fish in these ponds sometimes for

days or weeks at a time which further reduces growth during warm13 weather

Our data13 suggests that13 growth rates at the Bubbling13 Ponds Fish Hatchery are likely

as high as possible given13 the pond densities required to meet production goals and the Ich-shy‐

infested water that feeds the facility Sorting practices are successful in helping as many

fish as possible reach stocking length as fast as possible Unlined ponds may be able to

grow13 large13 fish at low13 densities13 but whatever factors allow13 for that13 growth are not13 able to

overcome high fish density The removal of invasive13 fis that act as13 a host for the13 parasite13

Ich fish from13 the Bubbling13 Ponds spring13 allowed the highest13 growth rate at 032 mmday13

(96 mmmonth) but that growth rate decreased again as Ich re-shy‐infested13 the13 hatchery13

Consistently13 achieving13 growth13 rates13 as high or substantially13 higher than13 this13 will likely13

require13 significant changes in rearing practices that may not be practical in order to13 reach13

numerical production13 goals

Two major changes that might result in higher growth rates are substantially

reducing fish density and modifying the way spring water is delivered to the facility (via

either repeated chemical treatments or enclosed concrete water diversions) to eliminate

Ich from13 the hatchery source water Other potential changes not address by our work

include13 flow-shy‐training razorbacks much previous literature including MSCP-shy‐funded13 work

on razorback suckers13 suggests13 that fish growing13 in flowing water will grow13 faster than fish

in still water (Jorgensen and Jobling 1994) Furthermore there are a wide variety of

potential benefits associated with growing13 fish13 in flowing13 water in addition13 to increased

growth13 rates13 (Davidson13 199713 Castro13 et al13 2011) Another option13 for increasing13 growth13

rates13 include13 changing to13 intensive13 culture13 in large circular13 tanks

Finally given that the stocking of smaller razorbacks has met with very little

success13 perhaps13 BPH13 goals13 could13 be13 changed from13 producing 12000 fish at 300+ mm per

year to a smaller number of very large fish each year Growing fewer larger fish could

potentially be accomplished in the same time frame as more smaller fish but a better

understanding13 of how density13 alters growth13 rate13 would13 be13 required to13 be13 confident of this

49

13

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower13 Colorado13 River Multi-shy‐Species13

Conservation Program13 (LCRMSCP) under Work Task C10 We13 thank Ty Wolters13 Tom13

Burke13 and Eric13 Volkman for their support of this research and Frank Agygos and Dave

Billingsly13 of the Bubbling13 Ponds Fish Hatchery13 for their willingness to participate in13 this

research13 and13 for their technical assistance We also thank the LCRMSCP fish group from13

Boulder City13 NV for their assistance with harvesting13 ponds and tagging13 fish13

50

13

Literature13 CitedAnders P J 1998 Conservation aquaculture and endangered species can objective science13

prevail13 over risk13 anxiety Fisheries 23(11) 28-shy‐31

Anderson R O and R M Nuemann 1996 Length weight and associated structural indicesPages 447 ndash 482 in B R Murphy13 and D13 W Willis13 editors13 Fisheries techniques13 2ndedtion American Fisheries13 Society13 Bethesda13 Maryland

Bain M B J T Finn and H E Brooks 1988 Streamflow regulation and fish communitystructure13 Ecology13 69382-shy‐392

Bays J H Zarbock R Whitman and T Murphy 2005 Conceptual design and managementof native13 fish refugia on the13 lower13 Colorado13 River In13 CL Spring13 and13 S Leoneditors Proceedings of two symposia Restoring native fish to the lower ColoradoRiver13 interactions13 of native and non-shy‐native13 fishes 13ndash1413 July13 1999 Las13 Vegas13 Nevada13 Restoring13 natural function within a modified riverine environment thelower Colorado River13 8ndash913 July13 1998 U S Fish and13 Wildlife13 Service Southwestern13 Region Albuquerque New Mexico Pages 167-shy‐177

Bertalanffy L Von 1957 Quantitative laws in metabolism13 and growth13 Q Rev Biology 32217 ndash 231

Bingham T B Scheer and C McAda 2003 Propagation facilities in Grand Valley (24 RoadHatchery Horsethief13 Ponds and13 grow-shy‐out ponds) for captive13 rearing13 ofendangered13 fishes for the13 upper13 Colorado13 River basin13 Colorado River RecoveryProgram FY2003 annual project report13 US Fish and13 Wildlife13 Service GrandJunction13 4pp

Birchell G J and K Christopherson 2004 Survival growth and recruitment of larval andjuvenile razorback13 sucker (Xyrauchen texanus) introduced13 into13 floodplain13 depressions13 of the13 Green River Utah13 Final report13 Upper13 Colorado13 RiverEndangered Fish Recovery Program13 Project No C-shy‐6RZ Publication Number 04-shy‐1513 Utah13 Division of Wildlife13 Resources Salt Lake13 City13 Utah13 67 pages

Brannon E L 1993 The perpetual oversight of hatchery programs Fishery Research 1819-shy‐27

Brett J R 1979 Environmental Factors and growth pages 599-shy‐67513 InW S Hoar13 D13 J13 Randall and J R Brett (eds) Fish Physiology Volume 8 Bioenergetics and GrowthAcademic Press New York

Brooks J E 1986 Annual reintroduction and monitoring report for razorback suckerXyrauchen texanus in the Gila River Basin Arizona 1985 US Fish and WildlifeService13 Offices of Endangered13 Species and Fishery13 Resources Albuquerque 23 pp

51

13

Brunson13 R E and K D13 Christopherson13 200513 Larval13 razorback13 sucker and bonytailsurvival and13 growth13 in the13 presence13 of nonnative13 fish in the13 Baeser13 floodplainwetland of the middle Green River Final report prepared for Upper13 Colorado RiverBasin Endangered Fish Recovery Program Project No C-shy‐6-shy‐rz-shy‐bt Publication13 No 05-shy‐26 Utah13 Division of Wildlife13 Resources13 Vernal13 32 pp

Bulkley R V and R Pimentel 1983 Temperature preference and avoidance by adultrazorback suckers Transactions of the American Fisheries Society 112601-shy‐607

Burke13 T13 199513 Rearing13 wild razorback13 sucker larvae in13 lake-shy‐side13 backwaters13 LakeMohave ArizonaNevada Proceedings of the Desert Fishes Council 2635

Busacker G P I R Adelman and E M Goolish13 199013 Growth13 Pages 363 ndash 387 in C BSchreck and p B Moyle editors Methods for fish biology American FisheriesSociety Bethesda Maryland

Castro V B Grisdale-shy‐Helland S J Helland T Kristensen S M Jorgensen J Helgrud13 GClaireaux A P Farrell A Krasnov and H Takle 2011 Aerobic training stimulatesgrowth and promotes disease resistance in Atlantic salmon (Salmo salar)Comparative Biochemistry and Physiology -shy‐ Part A Molecular amp IntegrativePhysiology13 160(2) 278-shy‐290

Czapla T E 2002 Facilities plan for the production of endangered fishes to meet statestocking13 plans13 as13 part of the13 Upper13 Colorado13 River Endangered13 Fish RecoveryProgram Upper Colorado River Basin Recovery Implementation Program US Fishand Wildlife Service13 Denver13 9 pp

Davidson W 1997 The effects13 of exercise13 training on teleost fish a review of recentliterature Comput Biochem Physiol 117A67ndash75

Figiel Jr C R 2005 Annual report fiscal year 2004 Willow Beach National13 Fish HatcheryUS Fish and Wildlife13 Service Willow Beach 17 pp

Figiel Jr C R M E Ulibarri G Carmichael J Seals and J N Hanson 2005 Intensive13 fish13 culture of warmwater native fishes at a coldwater fish hatchery Pages 164-shy‐16613 inProceedings of two symposia restoring native fish to the lower Colorado13 River13 interaction13 of native13 and13 non-shy‐native13 fishes July13 13-shy‐1413 1999 Las Vegas Nevada USFish and Wildlife Service Southwest Region Albuquerque New Mexico

Gerking13 S D 1978 Ecology of freshwater fish13 production13 Halstead Press13 New13 York

Gustafson W and Q Bradwisch 2000 Wahweap operation and maintenance -shy‐-shy‐ UtahColorado River Recovery Program FY 2000 annual project report Project No 29cUtah13 Division of Wildlife13 Resources Page AZ 3pp

52

13

Hamman R L 1985 Induced spawning of hatchery-shy‐reared13 razorback sucker ProgressivFish Culturist 47(3) 187-shy‐189

Hanson J N 1996 Annual report fiscal year 1996 Willow Beach National Fish HatcheryUS Fish and Wildlife Service13 Willow Beach 9pp

Irving D S Seversen and M Montagne 2004 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2004 annual project13 report Report No 29b US Fish and13 Wildlife13 Service Vernal 3pp

Jorgensen E H and13 M Jobling 1994 Feeding and13 growth13 of exercised13 and13 unexercised13 juvenile Atlantic salmon in freshwater and performance after transfer to seawaterAquaculture International 2 154-shy‐164

Kaeding L R and D B Osmundson 198913 Colorado13 Squawfish13 and13 razorback sucker grow-shy‐out pond studies as part of conservation measures for the green mountain andRuedi reservoir water sales Final report for agreement number 6-shy‐AA-shy‐60-shy‐00150

Koebele13 B P13 198513 Growth and the size hierarchy effect an experimental assessment ofthree proposed mechanisms activity differences disproportional food acquisition13 pysiological stress Environmental Biology of Fishes 12 181-shy‐188

Kretschmann A E and L L Leslie 2006 Razorback sucker (Xyrauchen texanus) status13 reproduction and recruitment in Senator Wash Reservoir CA Final Report13 to USBurea of Reclamation Cooperative Agreement No 00-shy‐FG-shy‐34-shy‐ 0009 p 32 ArizonaGame and Fish Department Phoenix

Marsh13 P13 C13 1987a13 Digestive tract13 contents13 of adult razorback suckers13 in Lake13 MohaveArizona-shy‐Nevada Transactions of the American Fisheries Society 116117-shy‐119

Marsh P C 1987b Native fishes at Buenos Aires National Wildlife Refuge and ArizonaState University Research Park Arizona opportunities for management researchand public13 education13 on13 endangered species13 Proceedings of the Desert13 FishesCouncil 1967-shy‐78

Marsh P C 1994 Rearing native Colorado River fishes in golf course ponds Arizona StateUniversity Tempe 22 + pages

Marsh13 P13 C13 200013 Fish population13 status and evaluation13 in13 the Cibola13 High Levee PondFinal report agreement number 99-shy‐FG-shy‐30-shy‐00051 US Bureau of ReclamationBoulder City13 Nevada13 20 pages

Marsh P C and C A Pacey 1998 Growth of wild adult razorback suckers13 in Lake13 Mohave13 Arizona-shy‐Nevada13 Final report13 US Bureau of Reclamation Boulder City Nevada 25pages + appendices

53

13

Marsh P C B R Kesner and C A Pacey 2005 Repatriation as s management strategy13 to13 conserve a critically13 imperiled fish species North American Journal of FisheriesManagement 25 547-shy‐556

Marsh P C and C A Pacey 2005 Immiscibility of native and non-shy‐native13 fishes Pages 59-shy‐63 inMJ13 Brouder13 CL13 Springer13 and CS13 Leon13 editors13 Proceedings of two13 symposia Restoring native fish to the lower Colorado River interactions of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 NV and13 Restoring natural13 function within a modified riverine environment the lower Colorado River13 July13 8-shy‐913 1998 Las Vegas NV US Fish and13 Wildlife13 Service Southwest Region AlbuquerqueNew Mexico

Marsh13 P13 C13 and J13 E Brooks13 198913 Predation13 by ictalurid catfishes as a deterrent13 toreestablishment of hatchery-shy‐reared13 razorback sucker The Southwestern Naturalist34188-shy‐195

Matthews R A 2005 Ichthyopthirus multifiliis Fouquet and Ichthyopthirosis infreshwater13 teleosts13 Pages13 159-shy‐218 in Advances in Parasitology volume 59 J RBaker R Muller D Rollinson (eds) Academic Press

McCarthy13 M S and W L Minckley 1987 Age estimation for razorback sucker (PiscesCatostomidae) from13 Lake Mohave Arizona and Nevada Journal of the Arizona-shy‐Nevada Academy of Science 2187-shy‐97

Minckley13 W L13 198313 Status of the razorback13 sucker13 Xyrauchen texanus (Abbot)13 in13 thelower Colorado River basin13 The Southwestern13 Naturalist13 28(2) 165-shy‐187

Minckley13 W L13 199113 Native fished of the Grand Canyon13 region an obituary13 Pages 124-shy‐177 in Colorado River ecology and dam13 management National Academy PressWashington13 DC

Minckley13 C13 O and M LaBarbara13 199913 Report13 on13 native fish grow-shy‐out facilities13 at Cibolaand Imperial National Wildlife Refuges 1993-shy‐199513 US Fish and13 Wildlife Service13 Parker Fishery Resources Office Parker Arizona

Modde13 T13 199613 Juvenile razorback sucker (Xyrauchen texanus) in a managed wetlandadjacent13 to the Green13 River13 Great13 Basin13 Naturalist13 56375-shy‐376

Modde T KP Burnham and E J Wick 1996 Population status of the razorback sucker13 inthe middle Green River (USA) Conservation13 biology 10 110-shy‐119

Modde13 T13 and G13 B Haines13 200513 Survival13 and growth of stocked razorback13 sucker andbonytail in multiple floodplain wetlands of the middle Green River under resetconditions13 Final report prepared for Upper Colorado13 River13 Basin RecoveryImplimentation Program US Fish and Wildlife Service Vernal 66 pp

54

13

Modde T Z H Bowen and D C Kitcheyan 2005 Spatial and temporal use of a spawning13 site in the middle Green River by wild hatchery-shy‐reared13 razorback suckers13 Transactions of the American Fisheries Society 134937-shy‐944

Mueller13 G13 199213 The native fish work13 group13 -shy‐ a multiagency endeavor to improve thestatus of the razorback sucker in Lake Mohave AZ-shy‐NV13 Proceedings of the DesertFishes Council 2369

Mueller G 1995 A program13 for maintaining the razorback sucker in Lake MohaveAmerican Fisheries Society Symposium 15127-shy‐135

Mueller13 G13 200613 Ecology of the bonytail13 and razorback13 sucker and the role of offchannelhabitats13 in their13 recovery Scientific13 investigations13 report 2006-shy‐5065 US GeologicalSurvey13 Denver

Mueller G and E Wick 1998 Testing of golf course ponds at Page Arizona for suitability13 as grow-shy‐out facility for razorback sucker using surplus fish from13 Ouray NationalFish Hatchery National Park Service US Fish and13 Wildlife13 Service and UtahDivision of Wildlife13 Resources 28 pages

Mueller13 G13 and T13 Burke13 200513 Survival13 of young13 razorback13 sucker (Xyrauchen texanus) inrelation to13 stocking rates13 (fishha)13 and13 in the presence13 or absence13 of predatorcommunities in Lake Mohave Arizona-shy‐Nevada13 Pages13 155-shy‐16313 in Proceedings of two13 symposia restoring native fish to the lower Colorado River interaction13 of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 Nevada US Fish and Wildlife13 Service Southwest Region Albuquerque New Mexico

Mueller13 G13 J13 Carpenter13 and P13 C13 Marsh13 200413 Cibola13 High Levee Pond annual report 2004US Geological Survey Fort Collins13 Science Center13 Colorado13 and Arizona StateUniversity Tempe 23 pages

Nesler T P K Christopherson J M Hudson C W McAda F Pfeifer and T E Czapla 2003An integrated stocking plan for razorback sucker bonytail and Colorado13 pikeminnow for the Upper Colorado River Endangered Fish Recovery ProgramAddendum13 to State Stocking Plans Upper Colorado River Basin Recovery13 Implementation Program 12 pp

Papoulias13 D and W13 L Minckley13 1992 Effects13 of foo availability13 on survival and growth13 of larval razorback suckers13 in ponds Transactions of the American Fisheries Society121340-shy‐355

Paukert13 C P D L Ward13 P J Sponholtz13 and K13 D Hilwig13 Effects13 of repeated hoopnetting13 on bonytail chub13 Journal of Freshwater13 Ecology13 20(4) 649-shy‐653

Pfeifer F M13 C Baker13 and M13 Montagne13 199913 Propagation13 facilities13 in the13 Grand Valley13 (24 Road13 Hatchery13 Horsethief13 Ponds and13 grow-shy‐out ponds) for captive rearing of

55

13

endangered13 fishes for the13 Upper Colorado13 River Basin13 Colorado13 River Recovery13 Program FY 99 annual project report Project No 29a13 US Fish and Wildlife Service13 Grand13 Junction13 5pp

Pfeifer F S Seversen and M Montagne 2003 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2003 annual reportProject No 29b13 US Fish and Wildlife13 Service Vernal13 4pp

Rabago-shy‐Castro J L Sanchez13 J G Perez-shy‐Castaneda R and13 Gonzalez-shy‐Gonzlez A 2006Effects of the prophylactic use of Romet-shy‐3013 and13 copper13 sulfate13 on growth13 condition13 and feeding13 indicies in13 channel13 catfish (Ictalurus punctatus) Aquaculture 253 343-shy‐349

Reinitz GL L E Orme and F N Hitzel 1979 Variations of body compositio and growth13 among strains of rainbow trout Transactions of the American Fisheries Society 108204-shy‐207

Ruppert13 J13 B P B Holden13 and P D Abate 1999 Age estimation and growth of razorbacksucker13 Xyrauchen texanus in Lake13 Mead Nevada Proceedings13 of the Desert FishesCouncil 3040

Schnoor K D and J Logan 2002 Operation and maintenance of JW Mumma nativeaquatic13 species restoration facility Colorado Colorado River Recovery Program FY2002 annual project report13 Project No 29d Colorado13 Division of Wildlife Alamosa3pp

Salisbury13 L13 1998 Factors13 affecting razorback13 sucker growth13 in Lake13 Mohave backwaters13 MS Thesis13 Unviersity13 of Nevada13 Las13 Vegas

Schooley J13 D13 and P C13 Marsh13 2007 Stocking of endangerdd13 razorback13 suckers13 in thelower Colorado River Basin13 over three decades 1974-shy‐2004 North American Journalof Fisheries Management 27 43-shy‐51

Severson S H H M Tyus and G B Haines 1992 An evaluation of feeds for raisingrazorback sucker Xyrauchen texanus Journal of Applied Aquaculture 155-shy‐65

Toney D P 1974 Observations13 on the13 propagation13 and13 rearing13 of two13 endangered species13 in a hatchery environment Proceedings of the Annual Conference of the Western13 Association of State Game and Fish Commissions 54 252-shy‐259

Tyus H M13 1998 Razorback sucker13 (Xyrauchen texanus) recovery plan13 University13 ofColorado Center for Limnology Boulder13 76 pages

Tyus H M13 and13 S H Severson 1990 Growth13 and13 survival of larval razorback suckers fedfive formulated diets The Progressive Fish Culturist 52197-shy‐200

56

13

Ulibarri M E 2003 Annual report fiscal year 2001 Dexter National Fish Hatchery13 andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 26 pages

Ulibarri M E 2003 Annual report fiscal year 2002 Dexter National Fish Hatchery andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 59 pages

USBR 2006 Lower13 Colorado13 River Multi-shy‐Species Conservation Program final fishaugmentation plan Boulder City 19 pp

USFWS 2002 Razorback sucker (Xyraouchen texanus) recovery goals Amendment andsupplement to the Razorback Sucker Recovery Plan13 US Fish and Wildlife Service13 Region 6 Denver13 Colorado

USFWS 1999 Annual report 1999 Ouray National Fish Hatchery Vernal 25pp

USFWS 2004 Management plan for the big-shy‐river13 fishes of the13 lower13 Colorado13 river basinamendment and supplement to the bonytail humpback chub Coloradopikeminnow and razorback sucker recovery plans

USFWS13 2005 Station13 profile13 of the13 Dexter13 National Fish Hatchery13 and Technology CenterUS Fish and Wildlife13 Service Dexter

Valdez R A P G Mangan R Smith and B Nilson 1982 Upper Colorado River fisheriesinvestigations13 inW H Miller J J Valentine D L Archer H M Tyus R A Valdezand L13 Kaeding13 editors13 Colorado River Fishery13 Project13 Part 2 Field13 investigations13 US Bureau of Reclamation Salt Lake City Utah

WBNFH 2004 Culture methods of the endangered razorback sucker Xyrauchen texanusUS Fish and Wildlife13 Service Willow Beach National Fish Hatchery13 8 pp

Ward D 2008 Effects of disease treatments on growth of razorback sucker ReportSubmitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 Inpartial fulfillment of work task C10 agreement number 06FG30039

Ward13 D13 M Childs and W Persons 2007 Factors13 affecting13 growth13 of razorback sucker13 (Xyrauchen texanus) in captivity Literature review and knowledge assessmentReport Submitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 In partial fulfillment of work task C10 agreement number 06FG30039

57

Appendices

Appendix 1 Survey Questions Survey of Razorback Sucker Culture in the

Southwestern United States

The enclosed survey is being distributed by the Arizona Game and Fish Department to razorback sucker culture facilities throughout

the Southwestern United States The purpose of this survey is to consolidate information regarding culture of this species so that

appropriate facility improvements can be considered for Bubbling Ponds Hatchery in Arizona Specifically we wish to increase

growth rate and production efficiency at the hatchery Information gathered in this survey will be summarized in a final report to US

Bureau of Reclamation in Boulder City NV and disseminated to all facilities that participate in the survey A workshop to discuss

the findings of this study as well as to share general information concerning razorback sucker culture will be organized by the

Arizona Game and Fish Department at the conclusion of this study and all participants will be invited

Thank you for taking the time to fill out this survey Please contact Mike Childs if you have questions or would like to discuss the

survey

Mike Childs

mchildssedonanet

(928) 639-1346

(928) 634-1279

Facility_____________________________________ Date___________________

Contact Phone _____________________________

ContactPerson_______________________________

Contact Email _______________________________

1 Water quality ranges at this culture facility

Season

Spring (Mar-May) Summer (Jun-Aug) Fall (Sept-Nov) Winter (Dec-Feb)

Temperature (C)

PH

DO (mgL)

PO4 (mgL)

TDS (mgL)

Hardness (mgL)

CaCO3

Pathogens

37

13

Conclusions

For razorback sucker survival is largely associated with stocking size Additional

focused13 research13 is therefore13 needed to13 identify13 ways13 to13 increase13 growth13 rates13 of captive-shy‐

reared13 razorback sucker Growth13 rate13 in fish is controlled13 by many factors including fish

size and age temperature density and feed ration which can all be highly correlated

Growth of razorback suckers is also inherently variable which makes the task of identifying

the key factors that13 affect13 growth in13 captivity even more difficult The focus at most

razorback rearing facilities13 is production so the13 types13 of data that are13 collected13 are13 often

insufficient for detailed13 evaluations13 of individual rearing13 practices13 on growth13 Surveys of

existing13 razorback sucker13 rearing facilities indicate that culture methods vary widely and

the types of growth data13 that13 are collected are not13 standardized13 Replicated studies with

detailed information on rearing location water temperature initial stocking size stocking

density and the sizes of all fish at harvest are needed in order to compare the effects of

individual rearing practices on growth This type of research will ultimately provide both

time and cost-shy‐savings to production facilities by reducing the amount of time necessary13 for

razorback sucker to reach stocking size improving overall production efficiency

Optimum13 rearing densities for razorback sucker larvae and juveniles remain to be

determined Current stocking densities will be very useful as starting point for more

detailed studies and although optimum13 rearing densities are likely to be site-shy‐specific13

replicated studies on density will provide a valuable reference for hatchery managers

Frequency13 of sorting is another13 area that needs13 further13 research Frequent

handling13 and13 sorting13 can13 cause13 stress-shy‐related13 reductions13 in growth but not sorting can

create dominance hierarchies that further reduce growth rates of subordinate individuals

The effects13 of sorting13 on overall fish growth13 in both13 pond and13 intensive13 culture13

environments warrant further investigation Research techniques for these types of

experiments are well understood and typically utilize a matrix of replicate ponds per

variable (Bays et al 2005) In every case accurate and complete records of sampling

procedures and data collection are needed in order to interpret data and make inferences

about13 growth rates (Busacker et13 al 1990)13

27

13

Additional research is also needed to evaluate long-shy‐term13 survival of stocked fish

reared in ponds compared to fish13 reared13 in intensive13 culture13 facilities13 Exercise13

conditioning13 and predator-shy‐recognition training may also increase survival of stocked fish

and be more economically feasible than rearing fish to increasingly larger sizes prior to

stocking13 The success13 of traditional fish hatchery programs is measured largely by the

number of fish stocked but hatchery programs for endangered species must measure

success in terms of long-shy‐term13 survival and species recovery (Brannon 1993 Anders 1998)

A specific list of research recommendations follows

Specific Research13 Recommendations13

bull Use replicated studies13 to establish optimum stocking13 densities13 for ponds13 and

tanks13 that can be used as13 a starting13 point for site specific refinement

bull Determine if sortinggrading13 improves13 overall growth rates13 in both ponds13 and

intensive culture facilities13

bull Investigate the use of artificial fertilizers13 to improve growth of both juvenile

and adult razorback suckers13 in ponds13

bull Determine if the razorback sucker diet gives13 better growth rates13 than cheaper

catfish or salmon feeds

bull Evaluate growth rates13 and production potential of new intensive culture

methods13 such as13 large circular tanks13

bull Evaluate13 long-shy‐term survival of fish produced from raceways13 and circular tanks13

compared to fish reared in ponds13

bull Evaluate more effective means13 of treating13 fish diseases13

bull Evaluate factors13 other than size that may increase post-shy‐stocking13 survival such

as13 exercise conditioning13 predator recognition training or rearing13 under more

natural settings13

28

13

II The Effect of Disease Treatments on Razorback Sucker

Growth

Section13 SummaryFormalin copper sulfate potassium permanganate and13 salt are all chemicals commonly13 used13 to13 treat13 Ichthyophthirius multifiliis outbreaks in captive razorback sucker (Xyrauchen13 texanus) Weexposed 190 juvenile13 razorback suckers (127 ndash 26 mm TL) to13 5 5-shy‐day treatments with13 each13 chemical to evaluate the effects13 these chemicals13 may have on growth Fish grew an average of23513 mm TL13 during the month13 study period Fish treated with formalin grew on average13 29mm TL (03 mmday) while fish treated with copper had the lowest growth averaging 20 mmTL (021 mmday) No significant differences in13 growth were observed among fish treatedwith any of the chemicals compared to untreated fish (pgt005) Reductions in growth13 as aresult of repeated chemical treatments are not likely the cause of differences in growth ratesamong13 facilities that raise razorback suckers Repeated chemical treatments may13 have otherimpacts to overall13 fitness or long-shy‐term survival but13 these effects were not13 evident13 in our study

29

13

Introduction

Preservation13 of razorback sucker13 (Xyrauchen texanus) currently13 depends on captive13

rearing and stocking programs until permanent solutions to factors that prevent wild13

recruitment are found Low survival of stocked razorback suckers (Brooks 1986 Marsh

and Brooks 198913 Marsh and Pacey13 2005) has caused target13 sizes for stocked fish to

steadily increase in efforts to reduce predation mortality (Marsh et al 2005 Schooley and

Marsh 2007) Rearing fish to larger sizes at hatcheries comes with increased costs and

creates the need to evaluate husbandry and rearing practices that may affect fish growth

Formalin copper sulfate potassium13 permanganate and salt are all chemicals

commonly used at razorback sucker rearing facilities to treat outbreaks of the protozoan

parasite13 Ichthyophthirius multifiliis ldquoIchrdquo is one of the most pathenogenic diseases of

cultured13 freshwater13 fishes (Matthews13 2005) and causes large13 losses in captive13 populations13

of endangered razorback sucker Each of these chemicals used to treat Ich only kill the free-shy‐

swimming life stage of the parasite13 requiring13 repeated doses over several13 days depending13

on water temperature These chemicals treatments are needed to prevent loss as a result

of disease outbreaks but the cumulative effects repeated disease treatments have on

growth13 are13 unknown

Copper13 sulfate13 has13 been shown to13 significantly13 reduce13 growth13 of channel catfish13 in

production13 ponds (Rabago-shy‐Castro13 2006) but it is unknown whether13 razorback suckers13

experience similar reduced growth following copper treatment Quantifying the impacts of

disease treatments on growth will help to interpret the wide differences in growth rates

observed13 at various13 razorback sucker13 production13 facilities13 throughout the13 southwest

(Ward et al 2007) If one chemical is found to have less detrimental impacts on growth

than another then it may be preferred for use as a disease treatment We evaluated growth

rates13 of razorback suckers13 under13 replicated13 and13 controlled13 conditions13 to13 assess13 effects13 of

repeated formalin copper sulfate and potassium permanganate and salt treatments on

growth13

Methods

We captured 190 juvenile razorback suckers from13 ponds at Bubbling Ponds Fish

Hatchery AZ using hoop nets or cast nets All fish were of the same age class and

30

13

averaged 179 mm total length (TL) (range13 = 127 ndash 262 mm TL)13 These fish were13 offspring13

of captive13 razorback sucker13 broodstock held13 at Dexter13 National13 Fish Hatchery13 NM13 (2007

year class) All fish were tagged with passive integrated transponder (PIT) tags and

quarantined for one month prior to the experiment to allow fish to recover from13 tagging

and become accustomed to being held in circular tanks

At the beginning of the study all fish were weighed measured and scanned for

individual tag numbers with 19 randomly selected fish placed into each13 of 10 8-shy‐foot

diameter circular tanks (Figure 2)13 Each13 tank contained13 two13 airstones13 and13 an13 individual

biofilter with a recirculating water pump (31 litersminute) that had been operating for

at least 1 month prior to the experiment to allow bacterial colonies to become

established Two tanks were designated as a control and did not receive any chemical

treatments while the other eight tanks received formalin copper sulfate potassium13

permanganate or salt treatments at two week intervals (two tanks per chemical

treatment) Formalin copper sulfate and potassium13 permanganate were treated at 1 part

per million (ppm) and salt was applied at 30 parts per thousand (ppt) These treatment

rates are commonly used to treat13 razorback13 suckers for ich at Bubbling13 Ponds Fish13

hatchery (Frank Agygos personal communication)

Figure 213 Photo ofexperimental tankswith individualbiofilters and aeration

31

13

Each treatment consisted of a series of doses applied on Wednesday Thursday and

Friday with a 90water change between each dose Biofilters were removed from13 all

tanks and held in a separate holding facility during treatments and then replaced on the

Monday following treatments after a 90water change This schedule allowed fish to be

exposed to chemical treatments for 5 consecutive days without water quality deteriorating

This 5-shy‐day chemical treatment was repeated every two weeks from13 July to October (97

days)13 for a total of 5 5-shy‐day treatments Water temperature in the treatment tanks ranged

from13 13degC (55degF) to 32degC (91degF)

Fish were fed a fixed ration of commercial razorback diet (Silvercup 4mm13 pellet)

once daily13 (2 percent body13 weight per day13 as calculated13 by13 average initial fish weight)13

At the end of the experiment all fish were again weighed measured and scanned for

individual tag numbers Growth of fish in each treatment group was compared using

analysis of variance (ANOVA) Any mortalities13 that occurred during the13 study13 were13

replaced with previously quarantined fish of equivalent size to maintain equal densities in

each13 tank13 but growth13 data was13 only13 recorded for fish which13 survived13 the13 entire13

experiment

Results

Fish at the13 start of the experiment averaged 179 mm TL (Range13 = 127 ndash 262 mm)

with no significant differences in fish length among treatment groups (F(4189) = 00183 p

gt 0999 ANOVA) On average fish grew 235 mm TL (024 mmday) during the 3 month

study13 Fish in tanks13 treated with formalin had the highest growth averaging 29 mm TL (03

mmday) while fish in tanks treated with copper had the lowest growth averaging 20 mm

TL (021 mmday) Fish in the control tanks averaged 213 mm TL in growth (022

mmday) (Figure13 3)13 Formalin-shy‐treated fish grew13 significantly faster than13 any other

treatment group but no13 significant differences in growth13 in length13 or weight were13

observed among fish treated with any of the chemicals compared to untreated (control)

fish (pgt005 ANOVA)

32

13

Figure 313 Average growthof razorback suckersexposed to a series of 5 5-shy‐day chemical treatmentsover a 97-shy‐day13 periodError bars representstandard error

Discussion13

Growth13 rates13 observed13 in our study13 (021 ndash 03 mmday) are low compared to those

reported13 in other13 studies13 of razorback sucker13 growth13 (0213 ndash 18 mmday) (Ward et al

2007) Using recirculating water systems for our study required filters to be removed and

replaced during treatments Stress to fish caused by removing and replacing filters within

the tanks as well as repeated water changes may have led to overall higher stress and

reduced growth rates compared to those reported for unconfined fish Growth in fish is

highly variable and is affected by many different physiological and environmental factors

including fish size density temperature amount of space and food (Brett 1979) We

strived to control each of these factors but other factors may have also influenced growth

in our experimental tanks During mid-shy‐summer water temperatures in the treatment

tanks reached 32degC (91degF) At these warm13 temperatures fish are very susceptible to

bacterial13 infections13 The slightly higher growth exhibited by fish in the formalin and

potassium13 permanganate treatments may have been the result of these two chemicals

33

13

being effective at controlling bacterial infections The differences in growth we measured

among treatment groups were not statistically significant and do not appear13 biologically13

meaningful during the relatively short duration of this study (97 days) although the

cumulative effects of slightly reduced growth could be biologically meaningful over longer

time frames

Reductions in growth13 as a result13 o repeated chemical treatments are not likely the

cause of differences in growth rates among facilities that raise razorback suckers

Repeated chemical treatments may have other impacts to overall fitness or long-shy‐term13

survival but these13 effects13 were13 not evident in our study It is more likely that the parasite

outbreaks themselves are the cause of different growth rates among razorback rearing

facilities rather than the chemical treatments used to treat the parasites We recommend

that hatchery managers continue to use the chemicals that are most effective at controlling

ldquoIchrdquo13 at their individual13 facilities

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower Colorado Rive Multi-shy‐species13

Conservation Plan under Work Task C10 We thank Ty Wolters and Tom13 Burke for their

support of this research and Frank Agygos and Dave Billingsly of the Bubbling Ponds Fish

Hatchery13 for their13 technical assistance13 and13 help with13 collecting13 fish

34

13

III13 Razorback Growth Rates at Bubbling Ponds ndash 2009-shy‐2011

Section13 SummaryExperimental studies at Bubbling Ponds Fish Hatchery AZ have strived to understand

factors that affect razorback sucker growth in captivity and identify ways to improve growthrates and maximize size at release Rather than performing experimental studies that wouldrequire major13 rearrangement (and likely reduced production)13 of hatchery operations our13 studies13 used normal variation in production techniques13 and practices13 to isolate factors13 thatmay modify growth rates

Our initial work identified razorback13 growth rates in13 lined ponds at standard fishdensity as 026 to13 028mmday (789 to 843 mmmonth) No significant differences in growthrate were observed among fish that had been in the pond only during the winter13 periodcompared to fish that had been in the pond the entire year indicating that water temperatures13 at Bubbling Ponds are high enough to allow fish to incorporate feed effectively year-shy‐roundHowever these growth rates are lower than most values reported from the literature fromnatural or semi-shy‐natural pond environments No significant differences in13 growth rate wereobserved13 between large and13 small fish13 within the 150 ndash 29 mm TL13 size range Additional worksuggests13 that razorback suckers13 tagged at over 300 mm TL had reduced growth rates (024mmday 73 mmmonth) as would be expected according to a typical Von13 Bertalanfy growthcurve although growth rates13 were only slightly less13 than the average growth rate for thehatchery (027513 mmday 82513 mmmonth)

Sorting13 to13 separate small fish from large fish after the first year of growth is practicedesigned13 to allow smaller fish to ldquocatch uprdquo to larger fish We found that13 this technique doesappear to13 improve growth rates of smaller fish Growth rates of sorted small razorback suckers(029 mmday 87mmmonth)13 were equal to that13 of larger13 fish (028 mmday 8413 mmmonth)indicating that sorting may have helped to offset their original slower growth trajectory

Bubbling Ponds Fish Hatchery grows razorbacks in 6 long deep ponds lined with heavyplastic 2 long deep13 earthen13 (unlined) ponds and three wide shallow earthen ponds The wideshallow ponds13 have historically produced very large fish at low density but have been found tomaintain much lower fish numbers than deeper ponds We found13 that growth13 rates ofrazorbacks kept at high density (4-shy‐700013 fish)13 in a wide shallow pond grew extremely slowly(024 mmday 726 mmmonth) This growth rate is among the slowest of any fish over theyears of our study and demonstrates that13 though the large ponds may produce large fish at lowdensity13 they are unable to overcome high13 fish13 densities

Finally one of the major factors influencing13 fish13 growth13 in hatcheries is disease onemajor summer-shy‐time disease at13 Bubbling Ponds is the ectoparasite Ich (Ichthiopthirusmultifiliis) To investigate the impact Ich has on razorback growth we eradicated fish from thespring and water conveyance ditch that supplies13 water to the hatchery using Rotenone This13 restoration effort was fairly short-shy‐lived (Ich returned to the hatchery within four months) but

35

13

growth13 rates of fish13 reared for four months without Ich present (031 mmday 92 mmmonth)were significantly higher than the following 8 months of growth for those same fish (022mmday 65 mmmonth) This disease-shy‐free growth rate is in fact faster than any13 otherprevious growth rates observed at the hatchery in our study

We conclude that growth rates at the Bubbling Ponds Fish Hatchery are likely as highas possible given the pond densities required to13 meet production goals and the Ich-shy‐infestedwater13 that feeds the facility Sorting practices are successful in helping as many fish as possiblereach stocking length as fast as possible Unlined ponds may be able to grow large fish at lowdensities but whatever factors allow for that growth13 are not able13 to overcome13 high fish densityThus the large lower ponds at Bubbling Ponds may be better utilized via renovation to13 deepenand line them

Disease is the most important factor limiting growth as may be expected to be the caseat many13 hatcheries While the spring renovation was not13 a complete success13 the dramaticreduction of fish populations in that habitat was enough to dramatically13 reduce13 the13 occurrenceof Ich at the hatchery13 Such open spring13 systems feeding a hatchery are a misfortune that canbe expected to transmit disease so we suggest that renovating the spring again to combat13 IchImproved techniques to divert water from13 the springs and more throuough treatment ofstream-shy‐side vegetation may improve the success of chemical treatment Successful renovationwould likely both improve growth rates and reduce chemical costs associated with treating Ichoutbreaks Even13 if complete renovation13 is impossible or impractical an13 effort to reduceinvasive fish density in the springs13 which act a vector for the parasite(and thereby reduce thelikelihood of13 Ich being transmitted into ponds) may still13 show dramatic improvements

36

13

Introduction

Conservation efforts13 for razorback sucker13 (Xyrauchen texanus)13 currently13 depend on

captive rearing and stocking programs Low survival of stocked razorback suckers (Brooks

1986 Marsh13 and13 Brooks13 1989 Marsh13 and13 Pacey13 2005) has13 caused13 target sizes for stocked13

fish to steadily increase in efforts to reduce predation mortality13 (Marsh13 et al13 2005

Schooley and Marsh 2007) Rearing fish to larger sizes at hatcheries comes with increased

costs and creates the need to evaluate husbandry and rearing practices that may affect fish

growth13 We evaluated growth13 rates13 of individual razorback suckers13 in ponds13 at Bubbling

Ponds Fish Hatchery13 using Passive Integrated13 Transponder (PIT) tags13 to13 obtain13 precise

growth information for individual fish so that valid comparisons of growth rates as related

to rearing practices can be made

Due to the critical nature of the razorback sucker stocking program we did not

design experimental studies that would require major rearrangement and potentially

reduce production of hatchery operations Instead our studies used normal variation in

production techniques and practices to isolate factors that may modify growth rates

Though this methodology dramatically limits replication and may limit our ability to

directly13 attribute13 differences in growth13 rates13 to13 the13 variables13 we13 investigate13 we13 were13 able13

to accomplish research goals without altering hatchery operations or impacting

production

From13 2009 through 2011 we conducted a series of observational13 growth13 studies to

determine growth rates of individual razorbacks at Bubbling Ponds The first set of

experiments included13 identifying13 growth13 rates13 in lined13 and13 unlined13 ponds determining

growth13 rates13 of fish at different13 sizes13 in13 relation13 to sorting13 practices and monitoring

razorback growth rates after removing the source of the ectoparasite13 Ich (Ichthiopthirus

multifiliis) from13 the hatchery water source13

Razorback growth rate in lined ponds

Our first growth study documented individual growth rates at normal density in 11

million gallon lined ponds13 over two13 years13 This is the standard13 grow-shy‐out process for

razorbacks13 at Bubbling Ponds We monitored growth of fish for a variety13 of sizes and13 the13

37

13

amount of time in a pond during the growing season These13 data give a snapshot of growth13

rates13 at the13 facility13 and13 provide13 the basis for comparisons throughout our study

Growth rate13 in an unlined pond

In addition13 to 6 ponds lined with heavy plastic13 sheeting13 Bubbling Ponds Fish13

Hatchery maintains two narrow and deep (same dimensions as lined ponds13 Figure13 4)13 and13

three large13 shallow unlined ponds These earthen13 ponds typically have vegetation and

associated aquatic invertebrates that may better simulate natural environments by

providing cover and improved food diversity or quality Therefore these unlined ponds

may be expected to produce higher growth rates and potentially improved survival that is

more similar to growth rates observed in more natural grow-shy‐out facilities13 Historically13 the13

large13 shallow13 ponds have produced very large fish when13 utilized at low13 fish density13 The

narrow13 deep earthen13 ponds are13 used to grow13 fry13 at high density in their first13 year of life

The major downside to unlined ponds is the difficulty in harvesting fish where a lined

pond might take 8-shy‐1013 people13 a half13 day13 to13 harvest13 lined13 ponds13 require13 intensive13 weeding13

to allow seines to be pulled and therefore require many more personnel-shy‐hours13 In addition13

to harvest challenges the shallow earthen ponds tend to suffer from13 dissolved oxygen

crashes during the summer Unlined ponds also may maintain higher13 populations13 of non-shy‐

target species such as bluegill sunfish mosquito fish and bullfrog tadpoles We measured

growth rates of suckers in a large shallow earthen pond for comparison to growth in lined

ponds13

Figure13 4 Lined13 and13 earthen ponds13 of similar dimensions (approx 1000000 gallons first

and second panels) and a large13 shallow13 earthen13 pond (third panel)

38

13

Effect of sorting on growth

Razorback13 suckers13 are13 currently13 sorted13 after their first13 year of growth13 They are13

typically removed from13 one of the13 upper earthen13 ponds and13 split into13 two13 lined13 ponds for

subsequent grow-shy‐out13 The larger13 fish (gt approximately 140 mm) are placed into one pond

and the smaller individuals in another It is possible that the larger fish were more

aggressive or adept13 at taking food so this sorting process is intended to allow smaller fish

to improve their growth rate

Effect of Ich on razorback sucker growth rates

We13 evaluated13 growth13 rates13 of razorback sucker13 in the13 presence13 and absence of the

ectoparasite13 Ich (Ichthiopthirus multifiliis) Ich outbreaks can occur in wild populations13 but

hatcheries13 have13 proven excellent locations13 for Ich because13 of very high fish densities13 which13

facilitate13 the13 transfer13 of Ich13 between13 fish This common fish parasite causes direct mortality13

to razorback13 suckers as well13 as secondary bacterial13 infections13

The open spring and13 ditch13 which13 provides water to the Bubbling13 Ponds Hatchery

has long13 been infested with mosquitofish (Gambusia affinis) that harbor13 the13 Ich parasite13

and allow13 it13 to enter the hatchery with incoming13 water13 The solution13 to13 the13 Ich problem13

was to remove the mosquitofish host using13 Rotenone Razorback13 sucker growth13 rates were13

then tracked in13 the absence of this parasite for 4 months and compared with growth rates

after Ich returned to the pond and from13 previous years

Methods

Razorback growth rate in lined ponds

On May 14 2008 141 razorback suckers were tagged with 12 mm PIT tags (1342

kHz) and placed in Pond 3 (approximately 1100000 gallons13 Figure13 4)13 at Bubbling13 Ponds

Fish Hatchery Fifty-shy‐three of these tags were recovered two months later when a large

Ichthyophthirius multifilis (Ich) outbreak killed many fish in the pond On October 15 2008

an additional13 145 PIT tagged13 fish were13 also placed into Pond13 3 On13 May13 14 2009 Pond13 3

was harvested and a total13 of 141 PIT tagged fish were recovered13 Of the tagged fish13 26 fish

had13 been13 in the13 pond since May13 of 2008 (378 days13 o growth) and 115 had been13 in13 the

39

13 40

pond since October13 15 2008 (211 days13 of growth) Numbers of fish in Pond 3 after the Ich

outbreak and for the majority of the period of growth were between 3 000 and 4000 fish

A Hobotempreg temperature13 logger13 was13 also13 installed13 in Pond 3 one meter below the water

surface13 near13 the13 outflow and13 recorded water temperature every 3 hours to allow analysis

of the effects of water temperature on growth rate (Figure13 5) This Hobotemp data is

representative of other pond temperatures throughout this study

In a second experiment 210 adult13 razorback suckers13 were13 PIT tagged13 on13 May 14

2009 and13 placed13 into13 Pond13 3 upper to13 evaluate13 growth13 rates13 of larger13 razorback suckers13 at

Bubbling13 Ponds Hatchery13 under current13 rearing13 conditions13 Size of these fish at tagging13

was (mean = 285 mm range = 205 ndash 396 mm) These fish remained in the pond for 257

days and were harvested on Jan 25 2010 to provide information on growth rates of larger

razorback suckers13 under13 current rearing conditions

Figure 513 Temperatures (degC) inrearing pond at BubblingPonds Hatchery from July toSept 2009 (top graph)13 andfrom Nov to Dec 2009 (Lowergraph) Temperaturesrecorded with a Hobotempregremote data logger13 every 3hours

13

Growth rate13 in an unlined pond

To document razorback sucker growth in earthen ponds we introduced13 225 tagged13

razorback suckers13 into13 Pond13 1 lower13 (Figure 4) in February 3 2010 Additional tagged fish

from13 other studies were added to the pond throughout the growing season and the density

of 1 lower reached a maximum13 of nearly 7000 fish in early summer 2010 Density was

reduced to approximately 6000 fish by capturing fish with hoop nets on June 3 2010 54 of

these fish were tagged fish and returned to 1 lower after being weighed and measured The

pond was harvested on January13 2713 2011 and a total13 of 254 tagged fish out13 of 4296 fish

total were removed from13 the pond The pond was harvested on January 27 2011 (358 days13

of growth) and the tagged fish were weighed and measured Total number of razorbacks in

the pond at harvest13 was 4296

Effect of sorting practices on growth rates

On March 1113 200913 Pond13 5 upper was13 harvested13 and13 split into13 two13 separate13 groups

Two hundred of the smaller fish (average size = 122 mm TL) were PIT tagged and placed

into13 Pond13 7 upper and13 200 of the13 larger13 fish (average = 160 mm TL) were PIT tagged and

placed int Pond13 8 upper Density13 in Pond13 7 was13 4500 fish and13 in Pond13 8 there13 were13 6500

fish These ponds were then harvested after 1 year and growth rates were compared to

give information on the effects of current sorting practices Hobotempreg temperature

loggers were installed in13 Ponds 7 and13 8 during13 the13 grow-shy‐out period with13 water13

temperature recorded every 2 hours13 (Figure13 6)

Effect of Ich on razorback sucker growth rates

Bubbling Ponds spring was treated with Rotenone (CFT Legumine 5) at a

concentration of 2 ppm13 to remove all mosquitofish from13 the spring The treatment

consisted of two treatments 6 hours in duration on two consecutive days (April 12 -shy‐ 13)

using13 drip13 stations13 and13 backpack sprayers13 followed13 by13 an13 additional 6 hours13 of

detoxification using sodium13 permanganate Although 12 mosquitofish were captured in the

spring pond the week following the treatments subsequent minnow trapping (20 traps

checked13 daily13 for 3 weeks) did not capture any additional fish until August 11 2010 when

41

13

juvenile mosquitofish were again detected in the spring pond Minnow traps have

subsequently been set daily with several hundred individuals removed To evaluate if Ich

was also again present in the spring we captured 15 mosquitofish from13 the spring pond on

three separate days and placed them13 in an aquaria at 25 degC with 5 longfin dace known to be

free of Ich These fish were monitored for 2 weeks with no signs of Ich developing This

indicates that even though mosquitofish have returned to the spring pond the parasite is no

longer present13 although how13 long13 this condition13 will13 persist13 is unknown13

On May 1113 201013 200 juvenile razorback13 suckers were harvested out13 of Pond 5

upper (2009 year Class from13 Dexter National Fish Hatchery) and were PIT tagged and

placed into Pond 8 to evaluate if growth rates at bubbling ponds hatchery have improved

following the renovation of the spring and the removal of the Ich parasite Unfortunately13

on Sept13 8 2010 Ich was13 again13 detected13 in Pond 8 and the pond was immediately seined

and 74 tagged fish were measured to obtain growth information for the 4-shy‐month period

during13 which13 the13 pond13 was13 Ich-shy‐free13

Figure13 6 Temperatures (degC) in rearingponds 7 and 8 at Bubbling Ponds Hatchery13 from March 2009 ndash March 201013 pond 7(top13 graph)13 and13 pond 8 (Lower13 graph)13 Temperatures recorded with a Hobotempregremote data logger every 3 hours

42

13

Results

Growth in Lined Ponds

Razorback suckers13 that had been13 in13 Pond 8 upper for the13 entire13 year13 grew an13

average of 0263 mmday (789 mmmonth) and razorback suckers that had been in the

pond for 7 months (Oct -shy‐ May) grew13 on13 average of 028 mmday (843 mmmonth) (Figure13

7) These growth13 rates13 did not significantly13 differ Fish density13 in Pond 3 during13 the13

majority of the growth period was13 00032 ndash 00036 fishgallon13 Additionally no13 significant

differences in growth rate were observed between fish smaller than 210 mm TL and fish

larger than 210 mm TL when all recaptured fish were combined

We also measured the growth rate of very large fish in a lined pond On Jan13 2513 201013

156 adult fish with PIT tags were recovered from13 Pond 3 upper13 These fish were13 in the13

pond for 257 days and experienced an average13 growth13 rate13 of 024mmday or 73

mmmonth (Figure13 7)13 This growth13 rate13 is slightly13 lower13 than13 the13 average13 growth13 rate13

observed13 at Bubbling13 Ponds Hatchery in other studies (0275 mmday 825 mmmonth)

but may not be biologically meaningful We would expect larger13 fish to13 have13 reduced

growth rates according to a typical Von Bertalanfy growth model (Bertalanffy 1957) but it

appears that13 over the size range we evaluated (300 -shy‐ 450 mm TL) growth rates have not

slowed significantly compared to that of smaller13 fish grown at Bubbling Ponds13 Hatchery

Growth13 of razorback suckers13 is known13 to13 slow as13 fish reach13 larger13 sizes but it appears13 this13

reduced growth rate may not really start to be biologically meaningful at Bubbling Ponds

Hatchery13 until razorback suckers13 exceed 450 mm TL

Growth in unlined ponds

Growth13 rates13 for the13 fish recaptured13 during13 the Pond 1 lower13 thinning13 (120 days13 in

the pond) was 024 plusmn 003 mmday (729 plusmn 090 mmmonth) (Figure13 8)13 Fish13 that were13 in

the pond for nearly the entire year grew13 an13 average13 of 024 plusmn 001 mmday (726 plusmn 027

mmmonth) These growth rates are surprisingly the lowest measured growth rates for

any part of our study and differ significantly from13 every other measured growth rate

except very large13 fish (Figure13 9)13 Separating13 out13 large fish that13 were in13 the pond for the

entire year makes no difference fish that were added to the pond at TL lt300 mm grew

43

13

Gro

wth

Rat

e (m

md

ay)

020

026

032

0244 plusmn 001 mmday (733 plusmn 028 mmmonth) and and those with TL gt= 300 mm at the

start of the experiment grew 022 plusmn 003 mmday (651 plusmn 101 mmmonth)

Razorback Growth Rates in Lined Ponds

Figure 7 Growth ofrazorback suckers in(mmday plusmn standard error)in Pond 8 upper in 2008-shy‐2009 An ANOVA did notdetect any significantdifferences

7 Months Full Year 300+ mm fish

Effects of sorting on growth

One hundred and seventy five tagged razorback suckers were recovered from13 Pond

8 upper13 on March13 24 2010 (378 days13 of growth)13 These were13 the13 larger sorted13 fish (gt140

mm TL) that came out of Pond13 5 on March13 11 2009 One13 hundred and13 twenty13 two13 tagged13

razorback suckers were also recovered from13 Pond13 7 upper on March13 31 2010 (385 days13 of

growth)13 These were13 the13 smaller sorted13 fish (lt140 mm TL) that came out of Pond13 5 on

March 1113 200913 No significant differences in growth rate (mmday) were observed among

larger fish in Pond 8 and smaller fish in Pond 7 (pgt005 ANOVA) (Figure 10)13 indicating

that13 sorting may have helped to offset the original slower growth trajectory of the smaller

fish Temperatures of Ponds 7 and 8 upper remained similar throughout the year13 (Figure

5)

44

13

13

13

Gro

wth

Rat

e (m

md

ay)

Gro

wth

Rat

e (m

md

ay)

020

026

032

020

026

032

Razorback Growth in an Unlined Pond

Figure 8 Growth of razorbacksuckers (mmday plusmn standard error) in Pond 1 lower (an unlined pond)in 2010-shy‐2011 An ANOVA did notdetect any significant differences

6 Months 12 Months lt 300 mm Fish 300+ mm Fish Growth Growth

Lined vs Earthen Ponds 1 year of growth

Figure 9 Growth of razorbacksuckers (mmday plusmn standard error) in lined and unlined ponds A t-shy‐test13 did not detect a significantdifference

Lined Pond Unlined Pond 1 Yr Growth 1 Yr Growth

45

13

Effect of Sorting G

row

th R

ate

(mm

day

) G

row

th R

ate

(mm

day

)

032

020

026

032

020

026

Smaller Fish Larger Fish

Effect of Ich

Figure 10 Average growthof razorback suckers(mmday plusmn standard error)that were size-shy‐sorted intosmall fish (pond 7) and largefish (pond 8) populations At-shy‐test did not detect asignificant difference

Figure 11 Average growth ofrazorback suckers (mmday plusmnstandard error) after Ich wasremovd from the hatcheryrsquos springand after Ich was again detected inthe pond The growth rate withoutIch is significantly higher than boththe rate after Ich and the ourstudyrsquos average annual growth ratein lined ponds (ANOVA p =00003)

Growth without Ich Growth With Ich Average Annual 4 months 4 months Growth Rate

46

13

Effect of Ich on razorback sucker growth rates

Seventy-shy‐four13 tagged13 razorback suckers13 were13 recovered from13 Pond 8 on September

15 2010 These fish had13 been13 in the pond for 4 months and experienced a growth rate of

032 mmday or 97 mmmonth (Figure13 11)13 This growth13 rate13 is significantly higher (p =

005 two sample t-shy‐test) than the mean growth rate for the same group13 of tagged fish after

Ich detection (022 mmday or 65 mmmonth) and significantly higher than any other

individual growth13 rates13 observed13 to13 date13 at Bubbling13 Ponds Hatchery13 (Figure13 11)13 If this13

growth13 rate13 were13 extended throughout13 the entire13 year13 fish on average from13 Ich-shy‐free13 ponds13

would be 16 mm longer than fish from13 ponds infested with Ich Studies conducted at

Bubbling Ponds hatchery in 2008 (Ward 2008) did not reveal any effects of the treatment

chemicals on razorback sucker growth rates so it13 is likely that13 the parasite outbreaks

themselves are causing reducing growth rates rather than the chemicals used to treat the

parasites13

Conclusions

Our results suggest that under typical hatchery operations (maximizing number of

fish produced)13 the growth13 rate13 of razorback13 suckers13 is relatively13 consistent at Bubbling13

Ponds hatchery13 at 02-shy‐03 mmday (6-shy‐9 mmmonth)13 but is lower than growth13 rates13 at

other13 facilities (02 ndash 18 mmday Ward et al 2007)13 This growth13 rate13 has13 been13 constant in

both lined and unlined ponds and at all fish densities we were able to measure To achieve13

growth13 rates13 substantially higher than this will likely require13 significant changes in rearing

practices that may not be practical in order to reach numerical production13 goals

Temperature is a key variable in fish growth but seasonal growth patterns

described13 above13 (Figure13 5) demonstrate that water temperatures are high enough in

winter to maintain razorback growth Differences in water temperature by season

currently13 do not fluctuate more than 10degC at Bubbling Ponds because of the continuous

supply of water flowing through each pond (approx 225 gallonsmin) These high water

flows appear to keep pond temperatures within the thermal preference13 for razorback

suckers13 (1213 -shy‐ 28 degC Bulkley and Pimentel 1983) throughout the entire year with

temperatures rarely dropping13 below 16deg13 C (Figures 513 6)13

47

13

Fish density is another key variable in fish growth and though the number of fish in

a pond during our study ranged from13 3000 to 700013 fish we13 did not find any13 correlation13

between13 density and growth rate13 This might yield two conclusions First13 razorback

growth13 may be changed equally13 by13 densities13 at the13 hatchery13 (ie13 a density13 of 3000 fish in a

pond is as stressful13 for razorbacks as a density13 of 7000 fish) An alternative is that other

factors13 such as disease outbreaks have13 stronger13 control over fish growth13 than13 density13

Fish density13 would13 have13 to13 be13 experimentally manipulated to test13 this13 and hatchery

operations (producing the maximum13 number of fish) prevented our manipulating density13

in ponds for this13 work The trouble with manipulating density demonstrates the difficulties

associated with changing13 hatchery13 practices experimenting with density would have

prevented BPH from13 meeting13 production13 goals Given that the stocking of smaller

razorbacks has met with very little success perhaps BPH goals could be changed from13

producing 12000 fish at 300+ mm per year to a smaller number of very large fish each

year Growing13 fewer13 larger13 fish could potentially be accomplished in the same time frame

as more smaller fish but a better understanding of how density alters growth rate would

be required to be confident13 of this

The very slow growth13 in the13 earthen13 unlined13 Pond 1 lower13 was very surprising We13

had13 anticipated13 that the13 diversified diet13 cover and13 other13 habitat features13 provided by13

unlined ponds would yield dramatically increased growth rates However these traits were

not enough to offset high fish densities and in fact the unlined pond in our study13 suffered

mortality to bring densities down to that observed normally in lined ponds

Our data13 suggest13 that razorbacks13 sucker13 growth13 rates13 are13 higher in lined13 ponds13

However we13 think the reasons13 for the13 very slow growth we observed13 in the13 unlined13 pond13

in our study13 is instead13 linked13 to13 the13 usage13 of Pond 1 lower13 during13 the13 study13 rather13 than13

intrinsic13 slow growth13 in earthen13 ponds First the pond was at extremely high density for at

least part of the study The volume of Pond 1 lower has not been estimated but hatchery

managers suggest 1500-shy‐2000 fish is an appropriate number of individuals so this pond

was at a very high density for much of the experiment Second dissolved oxygen is often

very low in the13 large13 earthen13 ponds during the heat of summer much lower than that of

lined ponds This will both limit the number of fish that can survive in the pond and almost

certainly13 increases stress13 of these13 fish potentially13 reducing growth13 The DO crashes also13

48

13

limit the amount of feed hatchery managers can give fish in these ponds sometimes for

days or weeks at a time which further reduces growth during warm13 weather

Our data13 suggests that13 growth rates at the Bubbling13 Ponds Fish Hatchery are likely

as high as possible given13 the pond densities required to meet production goals and the Ich-shy‐

infested water that feeds the facility Sorting practices are successful in helping as many

fish as possible reach stocking length as fast as possible Unlined ponds may be able to

grow13 large13 fish at low13 densities13 but whatever factors allow13 for that13 growth are not13 able to

overcome high fish density The removal of invasive13 fis that act as13 a host for the13 parasite13

Ich fish from13 the Bubbling13 Ponds spring13 allowed the highest13 growth rate at 032 mmday13

(96 mmmonth) but that growth rate decreased again as Ich re-shy‐infested13 the13 hatchery13

Consistently13 achieving13 growth13 rates13 as high or substantially13 higher than13 this13 will likely13

require13 significant changes in rearing practices that may not be practical in order to13 reach13

numerical production13 goals

Two major changes that might result in higher growth rates are substantially

reducing fish density and modifying the way spring water is delivered to the facility (via

either repeated chemical treatments or enclosed concrete water diversions) to eliminate

Ich from13 the hatchery source water Other potential changes not address by our work

include13 flow-shy‐training razorbacks much previous literature including MSCP-shy‐funded13 work

on razorback suckers13 suggests13 that fish growing13 in flowing water will grow13 faster than fish

in still water (Jorgensen and Jobling 1994) Furthermore there are a wide variety of

potential benefits associated with growing13 fish13 in flowing13 water in addition13 to increased

growth13 rates13 (Davidson13 199713 Castro13 et al13 2011) Another option13 for increasing13 growth13

rates13 include13 changing to13 intensive13 culture13 in large circular13 tanks

Finally given that the stocking of smaller razorbacks has met with very little

success13 perhaps13 BPH13 goals13 could13 be13 changed from13 producing 12000 fish at 300+ mm per

year to a smaller number of very large fish each year Growing fewer larger fish could

potentially be accomplished in the same time frame as more smaller fish but a better

understanding13 of how density13 alters growth13 rate13 would13 be13 required to13 be13 confident of this

49

13

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower13 Colorado13 River Multi-shy‐Species13

Conservation Program13 (LCRMSCP) under Work Task C10 We13 thank Ty Wolters13 Tom13

Burke13 and Eric13 Volkman for their support of this research and Frank Agygos and Dave

Billingsly13 of the Bubbling13 Ponds Fish Hatchery13 for their willingness to participate in13 this

research13 and13 for their technical assistance We also thank the LCRMSCP fish group from13

Boulder City13 NV for their assistance with harvesting13 ponds and tagging13 fish13

50

13

Literature13 CitedAnders P J 1998 Conservation aquaculture and endangered species can objective science13

prevail13 over risk13 anxiety Fisheries 23(11) 28-shy‐31

Anderson R O and R M Nuemann 1996 Length weight and associated structural indicesPages 447 ndash 482 in B R Murphy13 and D13 W Willis13 editors13 Fisheries techniques13 2ndedtion American Fisheries13 Society13 Bethesda13 Maryland

Bain M B J T Finn and H E Brooks 1988 Streamflow regulation and fish communitystructure13 Ecology13 69382-shy‐392

Bays J H Zarbock R Whitman and T Murphy 2005 Conceptual design and managementof native13 fish refugia on the13 lower13 Colorado13 River In13 CL Spring13 and13 S Leoneditors Proceedings of two symposia Restoring native fish to the lower ColoradoRiver13 interactions13 of native and non-shy‐native13 fishes 13ndash1413 July13 1999 Las13 Vegas13 Nevada13 Restoring13 natural function within a modified riverine environment thelower Colorado River13 8ndash913 July13 1998 U S Fish and13 Wildlife13 Service Southwestern13 Region Albuquerque New Mexico Pages 167-shy‐177

Bertalanffy L Von 1957 Quantitative laws in metabolism13 and growth13 Q Rev Biology 32217 ndash 231

Bingham T B Scheer and C McAda 2003 Propagation facilities in Grand Valley (24 RoadHatchery Horsethief13 Ponds and13 grow-shy‐out ponds) for captive13 rearing13 ofendangered13 fishes for the13 upper13 Colorado13 River basin13 Colorado River RecoveryProgram FY2003 annual project report13 US Fish and13 Wildlife13 Service GrandJunction13 4pp

Birchell G J and K Christopherson 2004 Survival growth and recruitment of larval andjuvenile razorback13 sucker (Xyrauchen texanus) introduced13 into13 floodplain13 depressions13 of the13 Green River Utah13 Final report13 Upper13 Colorado13 RiverEndangered Fish Recovery Program13 Project No C-shy‐6RZ Publication Number 04-shy‐1513 Utah13 Division of Wildlife13 Resources Salt Lake13 City13 Utah13 67 pages

Brannon E L 1993 The perpetual oversight of hatchery programs Fishery Research 1819-shy‐27

Brett J R 1979 Environmental Factors and growth pages 599-shy‐67513 InW S Hoar13 D13 J13 Randall and J R Brett (eds) Fish Physiology Volume 8 Bioenergetics and GrowthAcademic Press New York

Brooks J E 1986 Annual reintroduction and monitoring report for razorback suckerXyrauchen texanus in the Gila River Basin Arizona 1985 US Fish and WildlifeService13 Offices of Endangered13 Species and Fishery13 Resources Albuquerque 23 pp

51

13

Brunson13 R E and K D13 Christopherson13 200513 Larval13 razorback13 sucker and bonytailsurvival and13 growth13 in the13 presence13 of nonnative13 fish in the13 Baeser13 floodplainwetland of the middle Green River Final report prepared for Upper13 Colorado RiverBasin Endangered Fish Recovery Program Project No C-shy‐6-shy‐rz-shy‐bt Publication13 No 05-shy‐26 Utah13 Division of Wildlife13 Resources13 Vernal13 32 pp

Bulkley R V and R Pimentel 1983 Temperature preference and avoidance by adultrazorback suckers Transactions of the American Fisheries Society 112601-shy‐607

Burke13 T13 199513 Rearing13 wild razorback13 sucker larvae in13 lake-shy‐side13 backwaters13 LakeMohave ArizonaNevada Proceedings of the Desert Fishes Council 2635

Busacker G P I R Adelman and E M Goolish13 199013 Growth13 Pages 363 ndash 387 in C BSchreck and p B Moyle editors Methods for fish biology American FisheriesSociety Bethesda Maryland

Castro V B Grisdale-shy‐Helland S J Helland T Kristensen S M Jorgensen J Helgrud13 GClaireaux A P Farrell A Krasnov and H Takle 2011 Aerobic training stimulatesgrowth and promotes disease resistance in Atlantic salmon (Salmo salar)Comparative Biochemistry and Physiology -shy‐ Part A Molecular amp IntegrativePhysiology13 160(2) 278-shy‐290

Czapla T E 2002 Facilities plan for the production of endangered fishes to meet statestocking13 plans13 as13 part of the13 Upper13 Colorado13 River Endangered13 Fish RecoveryProgram Upper Colorado River Basin Recovery Implementation Program US Fishand Wildlife Service13 Denver13 9 pp

Davidson W 1997 The effects13 of exercise13 training on teleost fish a review of recentliterature Comput Biochem Physiol 117A67ndash75

Figiel Jr C R 2005 Annual report fiscal year 2004 Willow Beach National13 Fish HatcheryUS Fish and Wildlife13 Service Willow Beach 17 pp

Figiel Jr C R M E Ulibarri G Carmichael J Seals and J N Hanson 2005 Intensive13 fish13 culture of warmwater native fishes at a coldwater fish hatchery Pages 164-shy‐16613 inProceedings of two symposia restoring native fish to the lower Colorado13 River13 interaction13 of native13 and13 non-shy‐native13 fishes July13 13-shy‐1413 1999 Las Vegas Nevada USFish and Wildlife Service Southwest Region Albuquerque New Mexico

Gerking13 S D 1978 Ecology of freshwater fish13 production13 Halstead Press13 New13 York

Gustafson W and Q Bradwisch 2000 Wahweap operation and maintenance -shy‐-shy‐ UtahColorado River Recovery Program FY 2000 annual project report Project No 29cUtah13 Division of Wildlife13 Resources Page AZ 3pp

52

13

Hamman R L 1985 Induced spawning of hatchery-shy‐reared13 razorback sucker ProgressivFish Culturist 47(3) 187-shy‐189

Hanson J N 1996 Annual report fiscal year 1996 Willow Beach National Fish HatcheryUS Fish and Wildlife Service13 Willow Beach 9pp

Irving D S Seversen and M Montagne 2004 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2004 annual project13 report Report No 29b US Fish and13 Wildlife13 Service Vernal 3pp

Jorgensen E H and13 M Jobling 1994 Feeding and13 growth13 of exercised13 and13 unexercised13 juvenile Atlantic salmon in freshwater and performance after transfer to seawaterAquaculture International 2 154-shy‐164

Kaeding L R and D B Osmundson 198913 Colorado13 Squawfish13 and13 razorback sucker grow-shy‐out pond studies as part of conservation measures for the green mountain andRuedi reservoir water sales Final report for agreement number 6-shy‐AA-shy‐60-shy‐00150

Koebele13 B P13 198513 Growth and the size hierarchy effect an experimental assessment ofthree proposed mechanisms activity differences disproportional food acquisition13 pysiological stress Environmental Biology of Fishes 12 181-shy‐188

Kretschmann A E and L L Leslie 2006 Razorback sucker (Xyrauchen texanus) status13 reproduction and recruitment in Senator Wash Reservoir CA Final Report13 to USBurea of Reclamation Cooperative Agreement No 00-shy‐FG-shy‐34-shy‐ 0009 p 32 ArizonaGame and Fish Department Phoenix

Marsh13 P13 C13 1987a13 Digestive tract13 contents13 of adult razorback suckers13 in Lake13 MohaveArizona-shy‐Nevada Transactions of the American Fisheries Society 116117-shy‐119

Marsh P C 1987b Native fishes at Buenos Aires National Wildlife Refuge and ArizonaState University Research Park Arizona opportunities for management researchand public13 education13 on13 endangered species13 Proceedings of the Desert13 FishesCouncil 1967-shy‐78

Marsh P C 1994 Rearing native Colorado River fishes in golf course ponds Arizona StateUniversity Tempe 22 + pages

Marsh13 P13 C13 200013 Fish population13 status and evaluation13 in13 the Cibola13 High Levee PondFinal report agreement number 99-shy‐FG-shy‐30-shy‐00051 US Bureau of ReclamationBoulder City13 Nevada13 20 pages

Marsh P C and C A Pacey 1998 Growth of wild adult razorback suckers13 in Lake13 Mohave13 Arizona-shy‐Nevada13 Final report13 US Bureau of Reclamation Boulder City Nevada 25pages + appendices

53

13

Marsh P C B R Kesner and C A Pacey 2005 Repatriation as s management strategy13 to13 conserve a critically13 imperiled fish species North American Journal of FisheriesManagement 25 547-shy‐556

Marsh P C and C A Pacey 2005 Immiscibility of native and non-shy‐native13 fishes Pages 59-shy‐63 inMJ13 Brouder13 CL13 Springer13 and CS13 Leon13 editors13 Proceedings of two13 symposia Restoring native fish to the lower Colorado River interactions of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 NV and13 Restoring natural13 function within a modified riverine environment the lower Colorado River13 July13 8-shy‐913 1998 Las Vegas NV US Fish and13 Wildlife13 Service Southwest Region AlbuquerqueNew Mexico

Marsh13 P13 C13 and J13 E Brooks13 198913 Predation13 by ictalurid catfishes as a deterrent13 toreestablishment of hatchery-shy‐reared13 razorback sucker The Southwestern Naturalist34188-shy‐195

Matthews R A 2005 Ichthyopthirus multifiliis Fouquet and Ichthyopthirosis infreshwater13 teleosts13 Pages13 159-shy‐218 in Advances in Parasitology volume 59 J RBaker R Muller D Rollinson (eds) Academic Press

McCarthy13 M S and W L Minckley 1987 Age estimation for razorback sucker (PiscesCatostomidae) from13 Lake Mohave Arizona and Nevada Journal of the Arizona-shy‐Nevada Academy of Science 2187-shy‐97

Minckley13 W L13 198313 Status of the razorback13 sucker13 Xyrauchen texanus (Abbot)13 in13 thelower Colorado River basin13 The Southwestern13 Naturalist13 28(2) 165-shy‐187

Minckley13 W L13 199113 Native fished of the Grand Canyon13 region an obituary13 Pages 124-shy‐177 in Colorado River ecology and dam13 management National Academy PressWashington13 DC

Minckley13 C13 O and M LaBarbara13 199913 Report13 on13 native fish grow-shy‐out facilities13 at Cibolaand Imperial National Wildlife Refuges 1993-shy‐199513 US Fish and13 Wildlife Service13 Parker Fishery Resources Office Parker Arizona

Modde13 T13 199613 Juvenile razorback sucker (Xyrauchen texanus) in a managed wetlandadjacent13 to the Green13 River13 Great13 Basin13 Naturalist13 56375-shy‐376

Modde T KP Burnham and E J Wick 1996 Population status of the razorback sucker13 inthe middle Green River (USA) Conservation13 biology 10 110-shy‐119

Modde13 T13 and G13 B Haines13 200513 Survival13 and growth of stocked razorback13 sucker andbonytail in multiple floodplain wetlands of the middle Green River under resetconditions13 Final report prepared for Upper Colorado13 River13 Basin RecoveryImplimentation Program US Fish and Wildlife Service Vernal 66 pp

54

13

Modde T Z H Bowen and D C Kitcheyan 2005 Spatial and temporal use of a spawning13 site in the middle Green River by wild hatchery-shy‐reared13 razorback suckers13 Transactions of the American Fisheries Society 134937-shy‐944

Mueller13 G13 199213 The native fish work13 group13 -shy‐ a multiagency endeavor to improve thestatus of the razorback sucker in Lake Mohave AZ-shy‐NV13 Proceedings of the DesertFishes Council 2369

Mueller G 1995 A program13 for maintaining the razorback sucker in Lake MohaveAmerican Fisheries Society Symposium 15127-shy‐135

Mueller13 G13 200613 Ecology of the bonytail13 and razorback13 sucker and the role of offchannelhabitats13 in their13 recovery Scientific13 investigations13 report 2006-shy‐5065 US GeologicalSurvey13 Denver

Mueller G and E Wick 1998 Testing of golf course ponds at Page Arizona for suitability13 as grow-shy‐out facility for razorback sucker using surplus fish from13 Ouray NationalFish Hatchery National Park Service US Fish and13 Wildlife13 Service and UtahDivision of Wildlife13 Resources 28 pages

Mueller13 G13 and T13 Burke13 200513 Survival13 of young13 razorback13 sucker (Xyrauchen texanus) inrelation to13 stocking rates13 (fishha)13 and13 in the presence13 or absence13 of predatorcommunities in Lake Mohave Arizona-shy‐Nevada13 Pages13 155-shy‐16313 in Proceedings of two13 symposia restoring native fish to the lower Colorado River interaction13 of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 Nevada US Fish and Wildlife13 Service Southwest Region Albuquerque New Mexico

Mueller13 G13 J13 Carpenter13 and P13 C13 Marsh13 200413 Cibola13 High Levee Pond annual report 2004US Geological Survey Fort Collins13 Science Center13 Colorado13 and Arizona StateUniversity Tempe 23 pages

Nesler T P K Christopherson J M Hudson C W McAda F Pfeifer and T E Czapla 2003An integrated stocking plan for razorback sucker bonytail and Colorado13 pikeminnow for the Upper Colorado River Endangered Fish Recovery ProgramAddendum13 to State Stocking Plans Upper Colorado River Basin Recovery13 Implementation Program 12 pp

Papoulias13 D and W13 L Minckley13 1992 Effects13 of foo availability13 on survival and growth13 of larval razorback suckers13 in ponds Transactions of the American Fisheries Society121340-shy‐355

Paukert13 C P D L Ward13 P J Sponholtz13 and K13 D Hilwig13 Effects13 of repeated hoopnetting13 on bonytail chub13 Journal of Freshwater13 Ecology13 20(4) 649-shy‐653

Pfeifer F M13 C Baker13 and M13 Montagne13 199913 Propagation13 facilities13 in the13 Grand Valley13 (24 Road13 Hatchery13 Horsethief13 Ponds and13 grow-shy‐out ponds) for captive rearing of

55

13

endangered13 fishes for the13 Upper Colorado13 River Basin13 Colorado13 River Recovery13 Program FY 99 annual project report Project No 29a13 US Fish and Wildlife Service13 Grand13 Junction13 5pp

Pfeifer F S Seversen and M Montagne 2003 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2003 annual reportProject No 29b13 US Fish and Wildlife13 Service Vernal13 4pp

Rabago-shy‐Castro J L Sanchez13 J G Perez-shy‐Castaneda R and13 Gonzalez-shy‐Gonzlez A 2006Effects of the prophylactic use of Romet-shy‐3013 and13 copper13 sulfate13 on growth13 condition13 and feeding13 indicies in13 channel13 catfish (Ictalurus punctatus) Aquaculture 253 343-shy‐349

Reinitz GL L E Orme and F N Hitzel 1979 Variations of body compositio and growth13 among strains of rainbow trout Transactions of the American Fisheries Society 108204-shy‐207

Ruppert13 J13 B P B Holden13 and P D Abate 1999 Age estimation and growth of razorbacksucker13 Xyrauchen texanus in Lake13 Mead Nevada Proceedings13 of the Desert FishesCouncil 3040

Schnoor K D and J Logan 2002 Operation and maintenance of JW Mumma nativeaquatic13 species restoration facility Colorado Colorado River Recovery Program FY2002 annual project report13 Project No 29d Colorado13 Division of Wildlife Alamosa3pp

Salisbury13 L13 1998 Factors13 affecting razorback13 sucker growth13 in Lake13 Mohave backwaters13 MS Thesis13 Unviersity13 of Nevada13 Las13 Vegas

Schooley J13 D13 and P C13 Marsh13 2007 Stocking of endangerdd13 razorback13 suckers13 in thelower Colorado River Basin13 over three decades 1974-shy‐2004 North American Journalof Fisheries Management 27 43-shy‐51

Severson S H H M Tyus and G B Haines 1992 An evaluation of feeds for raisingrazorback sucker Xyrauchen texanus Journal of Applied Aquaculture 155-shy‐65

Toney D P 1974 Observations13 on the13 propagation13 and13 rearing13 of two13 endangered species13 in a hatchery environment Proceedings of the Annual Conference of the Western13 Association of State Game and Fish Commissions 54 252-shy‐259

Tyus H M13 1998 Razorback sucker13 (Xyrauchen texanus) recovery plan13 University13 ofColorado Center for Limnology Boulder13 76 pages

Tyus H M13 and13 S H Severson 1990 Growth13 and13 survival of larval razorback suckers fedfive formulated diets The Progressive Fish Culturist 52197-shy‐200

56

13

Ulibarri M E 2003 Annual report fiscal year 2001 Dexter National Fish Hatchery13 andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 26 pages

Ulibarri M E 2003 Annual report fiscal year 2002 Dexter National Fish Hatchery andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 59 pages

USBR 2006 Lower13 Colorado13 River Multi-shy‐Species Conservation Program final fishaugmentation plan Boulder City 19 pp

USFWS 2002 Razorback sucker (Xyraouchen texanus) recovery goals Amendment andsupplement to the Razorback Sucker Recovery Plan13 US Fish and Wildlife Service13 Region 6 Denver13 Colorado

USFWS 1999 Annual report 1999 Ouray National Fish Hatchery Vernal 25pp

USFWS 2004 Management plan for the big-shy‐river13 fishes of the13 lower13 Colorado13 river basinamendment and supplement to the bonytail humpback chub Coloradopikeminnow and razorback sucker recovery plans

USFWS13 2005 Station13 profile13 of the13 Dexter13 National Fish Hatchery13 and Technology CenterUS Fish and Wildlife13 Service Dexter

Valdez R A P G Mangan R Smith and B Nilson 1982 Upper Colorado River fisheriesinvestigations13 inW H Miller J J Valentine D L Archer H M Tyus R A Valdezand L13 Kaeding13 editors13 Colorado River Fishery13 Project13 Part 2 Field13 investigations13 US Bureau of Reclamation Salt Lake City Utah

WBNFH 2004 Culture methods of the endangered razorback sucker Xyrauchen texanusUS Fish and Wildlife13 Service Willow Beach National Fish Hatchery13 8 pp

Ward D 2008 Effects of disease treatments on growth of razorback sucker ReportSubmitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 Inpartial fulfillment of work task C10 agreement number 06FG30039

Ward13 D13 M Childs and W Persons 2007 Factors13 affecting13 growth13 of razorback sucker13 (Xyrauchen texanus) in captivity Literature review and knowledge assessmentReport Submitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 In partial fulfillment of work task C10 agreement number 06FG30039

57

Appendices

Appendix 1 Survey Questions Survey of Razorback Sucker Culture in the

Southwestern United States

The enclosed survey is being distributed by the Arizona Game and Fish Department to razorback sucker culture facilities throughout

the Southwestern United States The purpose of this survey is to consolidate information regarding culture of this species so that

appropriate facility improvements can be considered for Bubbling Ponds Hatchery in Arizona Specifically we wish to increase

growth rate and production efficiency at the hatchery Information gathered in this survey will be summarized in a final report to US

Bureau of Reclamation in Boulder City NV and disseminated to all facilities that participate in the survey A workshop to discuss

the findings of this study as well as to share general information concerning razorback sucker culture will be organized by the

Arizona Game and Fish Department at the conclusion of this study and all participants will be invited

Thank you for taking the time to fill out this survey Please contact Mike Childs if you have questions or would like to discuss the

survey

Mike Childs

mchildssedonanet

(928) 639-1346

(928) 634-1279

Facility_____________________________________ Date___________________

Contact Phone _____________________________

ContactPerson_______________________________

Contact Email _______________________________

1 Water quality ranges at this culture facility

Season

Spring (Mar-May) Summer (Jun-Aug) Fall (Sept-Nov) Winter (Dec-Feb)

Temperature (C)

PH

DO (mgL)

PO4 (mgL)

TDS (mgL)

Hardness (mgL)

CaCO3

Pathogens

37

13

Additional research is also needed to evaluate long-shy‐term13 survival of stocked fish

reared in ponds compared to fish13 reared13 in intensive13 culture13 facilities13 Exercise13

conditioning13 and predator-shy‐recognition training may also increase survival of stocked fish

and be more economically feasible than rearing fish to increasingly larger sizes prior to

stocking13 The success13 of traditional fish hatchery programs is measured largely by the

number of fish stocked but hatchery programs for endangered species must measure

success in terms of long-shy‐term13 survival and species recovery (Brannon 1993 Anders 1998)

A specific list of research recommendations follows

Specific Research13 Recommendations13

bull Use replicated studies13 to establish optimum stocking13 densities13 for ponds13 and

tanks13 that can be used as13 a starting13 point for site specific refinement

bull Determine if sortinggrading13 improves13 overall growth rates13 in both ponds13 and

intensive culture facilities13

bull Investigate the use of artificial fertilizers13 to improve growth of both juvenile

and adult razorback suckers13 in ponds13

bull Determine if the razorback sucker diet gives13 better growth rates13 than cheaper

catfish or salmon feeds

bull Evaluate growth rates13 and production potential of new intensive culture

methods13 such as13 large circular tanks13

bull Evaluate13 long-shy‐term survival of fish produced from raceways13 and circular tanks13

compared to fish reared in ponds13

bull Evaluate more effective means13 of treating13 fish diseases13

bull Evaluate factors13 other than size that may increase post-shy‐stocking13 survival such

as13 exercise conditioning13 predator recognition training or rearing13 under more

natural settings13

28

13

II The Effect of Disease Treatments on Razorback Sucker

Growth

Section13 SummaryFormalin copper sulfate potassium permanganate and13 salt are all chemicals commonly13 used13 to13 treat13 Ichthyophthirius multifiliis outbreaks in captive razorback sucker (Xyrauchen13 texanus) Weexposed 190 juvenile13 razorback suckers (127 ndash 26 mm TL) to13 5 5-shy‐day treatments with13 each13 chemical to evaluate the effects13 these chemicals13 may have on growth Fish grew an average of23513 mm TL13 during the month13 study period Fish treated with formalin grew on average13 29mm TL (03 mmday) while fish treated with copper had the lowest growth averaging 20 mmTL (021 mmday) No significant differences in13 growth were observed among fish treatedwith any of the chemicals compared to untreated fish (pgt005) Reductions in growth13 as aresult of repeated chemical treatments are not likely the cause of differences in growth ratesamong13 facilities that raise razorback suckers Repeated chemical treatments may13 have otherimpacts to overall13 fitness or long-shy‐term survival but13 these effects were not13 evident13 in our study

29

13

Introduction

Preservation13 of razorback sucker13 (Xyrauchen texanus) currently13 depends on captive13

rearing and stocking programs until permanent solutions to factors that prevent wild13

recruitment are found Low survival of stocked razorback suckers (Brooks 1986 Marsh

and Brooks 198913 Marsh and Pacey13 2005) has caused target13 sizes for stocked fish to

steadily increase in efforts to reduce predation mortality (Marsh et al 2005 Schooley and

Marsh 2007) Rearing fish to larger sizes at hatcheries comes with increased costs and

creates the need to evaluate husbandry and rearing practices that may affect fish growth

Formalin copper sulfate potassium13 permanganate and salt are all chemicals

commonly used at razorback sucker rearing facilities to treat outbreaks of the protozoan

parasite13 Ichthyophthirius multifiliis ldquoIchrdquo is one of the most pathenogenic diseases of

cultured13 freshwater13 fishes (Matthews13 2005) and causes large13 losses in captive13 populations13

of endangered razorback sucker Each of these chemicals used to treat Ich only kill the free-shy‐

swimming life stage of the parasite13 requiring13 repeated doses over several13 days depending13

on water temperature These chemicals treatments are needed to prevent loss as a result

of disease outbreaks but the cumulative effects repeated disease treatments have on

growth13 are13 unknown

Copper13 sulfate13 has13 been shown to13 significantly13 reduce13 growth13 of channel catfish13 in

production13 ponds (Rabago-shy‐Castro13 2006) but it is unknown whether13 razorback suckers13

experience similar reduced growth following copper treatment Quantifying the impacts of

disease treatments on growth will help to interpret the wide differences in growth rates

observed13 at various13 razorback sucker13 production13 facilities13 throughout the13 southwest

(Ward et al 2007) If one chemical is found to have less detrimental impacts on growth

than another then it may be preferred for use as a disease treatment We evaluated growth

rates13 of razorback suckers13 under13 replicated13 and13 controlled13 conditions13 to13 assess13 effects13 of

repeated formalin copper sulfate and potassium permanganate and salt treatments on

growth13

Methods

We captured 190 juvenile razorback suckers from13 ponds at Bubbling Ponds Fish

Hatchery AZ using hoop nets or cast nets All fish were of the same age class and

30

13

averaged 179 mm total length (TL) (range13 = 127 ndash 262 mm TL)13 These fish were13 offspring13

of captive13 razorback sucker13 broodstock held13 at Dexter13 National13 Fish Hatchery13 NM13 (2007

year class) All fish were tagged with passive integrated transponder (PIT) tags and

quarantined for one month prior to the experiment to allow fish to recover from13 tagging

and become accustomed to being held in circular tanks

At the beginning of the study all fish were weighed measured and scanned for

individual tag numbers with 19 randomly selected fish placed into each13 of 10 8-shy‐foot

diameter circular tanks (Figure 2)13 Each13 tank contained13 two13 airstones13 and13 an13 individual

biofilter with a recirculating water pump (31 litersminute) that had been operating for

at least 1 month prior to the experiment to allow bacterial colonies to become

established Two tanks were designated as a control and did not receive any chemical

treatments while the other eight tanks received formalin copper sulfate potassium13

permanganate or salt treatments at two week intervals (two tanks per chemical

treatment) Formalin copper sulfate and potassium13 permanganate were treated at 1 part

per million (ppm) and salt was applied at 30 parts per thousand (ppt) These treatment

rates are commonly used to treat13 razorback13 suckers for ich at Bubbling13 Ponds Fish13

hatchery (Frank Agygos personal communication)

Figure 213 Photo ofexperimental tankswith individualbiofilters and aeration

31

13

Each treatment consisted of a series of doses applied on Wednesday Thursday and

Friday with a 90water change between each dose Biofilters were removed from13 all

tanks and held in a separate holding facility during treatments and then replaced on the

Monday following treatments after a 90water change This schedule allowed fish to be

exposed to chemical treatments for 5 consecutive days without water quality deteriorating

This 5-shy‐day chemical treatment was repeated every two weeks from13 July to October (97

days)13 for a total of 5 5-shy‐day treatments Water temperature in the treatment tanks ranged

from13 13degC (55degF) to 32degC (91degF)

Fish were fed a fixed ration of commercial razorback diet (Silvercup 4mm13 pellet)

once daily13 (2 percent body13 weight per day13 as calculated13 by13 average initial fish weight)13

At the end of the experiment all fish were again weighed measured and scanned for

individual tag numbers Growth of fish in each treatment group was compared using

analysis of variance (ANOVA) Any mortalities13 that occurred during the13 study13 were13

replaced with previously quarantined fish of equivalent size to maintain equal densities in

each13 tank13 but growth13 data was13 only13 recorded for fish which13 survived13 the13 entire13

experiment

Results

Fish at the13 start of the experiment averaged 179 mm TL (Range13 = 127 ndash 262 mm)

with no significant differences in fish length among treatment groups (F(4189) = 00183 p

gt 0999 ANOVA) On average fish grew 235 mm TL (024 mmday) during the 3 month

study13 Fish in tanks13 treated with formalin had the highest growth averaging 29 mm TL (03

mmday) while fish in tanks treated with copper had the lowest growth averaging 20 mm

TL (021 mmday) Fish in the control tanks averaged 213 mm TL in growth (022

mmday) (Figure13 3)13 Formalin-shy‐treated fish grew13 significantly faster than13 any other

treatment group but no13 significant differences in growth13 in length13 or weight were13

observed among fish treated with any of the chemicals compared to untreated (control)

fish (pgt005 ANOVA)

32

13

Figure 313 Average growthof razorback suckersexposed to a series of 5 5-shy‐day chemical treatmentsover a 97-shy‐day13 periodError bars representstandard error

Discussion13

Growth13 rates13 observed13 in our study13 (021 ndash 03 mmday) are low compared to those

reported13 in other13 studies13 of razorback sucker13 growth13 (0213 ndash 18 mmday) (Ward et al

2007) Using recirculating water systems for our study required filters to be removed and

replaced during treatments Stress to fish caused by removing and replacing filters within

the tanks as well as repeated water changes may have led to overall higher stress and

reduced growth rates compared to those reported for unconfined fish Growth in fish is

highly variable and is affected by many different physiological and environmental factors

including fish size density temperature amount of space and food (Brett 1979) We

strived to control each of these factors but other factors may have also influenced growth

in our experimental tanks During mid-shy‐summer water temperatures in the treatment

tanks reached 32degC (91degF) At these warm13 temperatures fish are very susceptible to

bacterial13 infections13 The slightly higher growth exhibited by fish in the formalin and

potassium13 permanganate treatments may have been the result of these two chemicals

33

13

being effective at controlling bacterial infections The differences in growth we measured

among treatment groups were not statistically significant and do not appear13 biologically13

meaningful during the relatively short duration of this study (97 days) although the

cumulative effects of slightly reduced growth could be biologically meaningful over longer

time frames

Reductions in growth13 as a result13 o repeated chemical treatments are not likely the

cause of differences in growth rates among facilities that raise razorback suckers

Repeated chemical treatments may have other impacts to overall fitness or long-shy‐term13

survival but these13 effects13 were13 not evident in our study It is more likely that the parasite

outbreaks themselves are the cause of different growth rates among razorback rearing

facilities rather than the chemical treatments used to treat the parasites We recommend

that hatchery managers continue to use the chemicals that are most effective at controlling

ldquoIchrdquo13 at their individual13 facilities

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower Colorado Rive Multi-shy‐species13

Conservation Plan under Work Task C10 We thank Ty Wolters and Tom13 Burke for their

support of this research and Frank Agygos and Dave Billingsly of the Bubbling Ponds Fish

Hatchery13 for their13 technical assistance13 and13 help with13 collecting13 fish

34

13

III13 Razorback Growth Rates at Bubbling Ponds ndash 2009-shy‐2011

Section13 SummaryExperimental studies at Bubbling Ponds Fish Hatchery AZ have strived to understand

factors that affect razorback sucker growth in captivity and identify ways to improve growthrates and maximize size at release Rather than performing experimental studies that wouldrequire major13 rearrangement (and likely reduced production)13 of hatchery operations our13 studies13 used normal variation in production techniques13 and practices13 to isolate factors13 thatmay modify growth rates

Our initial work identified razorback13 growth rates in13 lined ponds at standard fishdensity as 026 to13 028mmday (789 to 843 mmmonth) No significant differences in growthrate were observed among fish that had been in the pond only during the winter13 periodcompared to fish that had been in the pond the entire year indicating that water temperatures13 at Bubbling Ponds are high enough to allow fish to incorporate feed effectively year-shy‐roundHowever these growth rates are lower than most values reported from the literature fromnatural or semi-shy‐natural pond environments No significant differences in13 growth rate wereobserved13 between large and13 small fish13 within the 150 ndash 29 mm TL13 size range Additional worksuggests13 that razorback suckers13 tagged at over 300 mm TL had reduced growth rates (024mmday 73 mmmonth) as would be expected according to a typical Von13 Bertalanfy growthcurve although growth rates13 were only slightly less13 than the average growth rate for thehatchery (027513 mmday 82513 mmmonth)

Sorting13 to13 separate small fish from large fish after the first year of growth is practicedesigned13 to allow smaller fish to ldquocatch uprdquo to larger fish We found that13 this technique doesappear to13 improve growth rates of smaller fish Growth rates of sorted small razorback suckers(029 mmday 87mmmonth)13 were equal to that13 of larger13 fish (028 mmday 8413 mmmonth)indicating that sorting may have helped to offset their original slower growth trajectory

Bubbling Ponds Fish Hatchery grows razorbacks in 6 long deep ponds lined with heavyplastic 2 long deep13 earthen13 (unlined) ponds and three wide shallow earthen ponds The wideshallow ponds13 have historically produced very large fish at low density but have been found tomaintain much lower fish numbers than deeper ponds We found13 that growth13 rates ofrazorbacks kept at high density (4-shy‐700013 fish)13 in a wide shallow pond grew extremely slowly(024 mmday 726 mmmonth) This growth rate is among the slowest of any fish over theyears of our study and demonstrates that13 though the large ponds may produce large fish at lowdensity13 they are unable to overcome high13 fish13 densities

Finally one of the major factors influencing13 fish13 growth13 in hatcheries is disease onemajor summer-shy‐time disease at13 Bubbling Ponds is the ectoparasite Ich (Ichthiopthirusmultifiliis) To investigate the impact Ich has on razorback growth we eradicated fish from thespring and water conveyance ditch that supplies13 water to the hatchery using Rotenone This13 restoration effort was fairly short-shy‐lived (Ich returned to the hatchery within four months) but

35

13

growth13 rates of fish13 reared for four months without Ich present (031 mmday 92 mmmonth)were significantly higher than the following 8 months of growth for those same fish (022mmday 65 mmmonth) This disease-shy‐free growth rate is in fact faster than any13 otherprevious growth rates observed at the hatchery in our study

We conclude that growth rates at the Bubbling Ponds Fish Hatchery are likely as highas possible given the pond densities required to13 meet production goals and the Ich-shy‐infestedwater13 that feeds the facility Sorting practices are successful in helping as many fish as possiblereach stocking length as fast as possible Unlined ponds may be able to grow large fish at lowdensities but whatever factors allow for that growth13 are not able13 to overcome13 high fish densityThus the large lower ponds at Bubbling Ponds may be better utilized via renovation to13 deepenand line them

Disease is the most important factor limiting growth as may be expected to be the caseat many13 hatcheries While the spring renovation was not13 a complete success13 the dramaticreduction of fish populations in that habitat was enough to dramatically13 reduce13 the13 occurrenceof Ich at the hatchery13 Such open spring13 systems feeding a hatchery are a misfortune that canbe expected to transmit disease so we suggest that renovating the spring again to combat13 IchImproved techniques to divert water from13 the springs and more throuough treatment ofstream-shy‐side vegetation may improve the success of chemical treatment Successful renovationwould likely both improve growth rates and reduce chemical costs associated with treating Ichoutbreaks Even13 if complete renovation13 is impossible or impractical an13 effort to reduceinvasive fish density in the springs13 which act a vector for the parasite(and thereby reduce thelikelihood of13 Ich being transmitted into ponds) may still13 show dramatic improvements

36

13

Introduction

Conservation efforts13 for razorback sucker13 (Xyrauchen texanus)13 currently13 depend on

captive rearing and stocking programs Low survival of stocked razorback suckers (Brooks

1986 Marsh13 and13 Brooks13 1989 Marsh13 and13 Pacey13 2005) has13 caused13 target sizes for stocked13

fish to steadily increase in efforts to reduce predation mortality13 (Marsh13 et al13 2005

Schooley and Marsh 2007) Rearing fish to larger sizes at hatcheries comes with increased

costs and creates the need to evaluate husbandry and rearing practices that may affect fish

growth13 We evaluated growth13 rates13 of individual razorback suckers13 in ponds13 at Bubbling

Ponds Fish Hatchery13 using Passive Integrated13 Transponder (PIT) tags13 to13 obtain13 precise

growth information for individual fish so that valid comparisons of growth rates as related

to rearing practices can be made

Due to the critical nature of the razorback sucker stocking program we did not

design experimental studies that would require major rearrangement and potentially

reduce production of hatchery operations Instead our studies used normal variation in

production techniques and practices to isolate factors that may modify growth rates

Though this methodology dramatically limits replication and may limit our ability to

directly13 attribute13 differences in growth13 rates13 to13 the13 variables13 we13 investigate13 we13 were13 able13

to accomplish research goals without altering hatchery operations or impacting

production

From13 2009 through 2011 we conducted a series of observational13 growth13 studies to

determine growth rates of individual razorbacks at Bubbling Ponds The first set of

experiments included13 identifying13 growth13 rates13 in lined13 and13 unlined13 ponds determining

growth13 rates13 of fish at different13 sizes13 in13 relation13 to sorting13 practices and monitoring

razorback growth rates after removing the source of the ectoparasite13 Ich (Ichthiopthirus

multifiliis) from13 the hatchery water source13

Razorback growth rate in lined ponds

Our first growth study documented individual growth rates at normal density in 11

million gallon lined ponds13 over two13 years13 This is the standard13 grow-shy‐out process for

razorbacks13 at Bubbling Ponds We monitored growth of fish for a variety13 of sizes and13 the13

37

13

amount of time in a pond during the growing season These13 data give a snapshot of growth13

rates13 at the13 facility13 and13 provide13 the basis for comparisons throughout our study

Growth rate13 in an unlined pond

In addition13 to 6 ponds lined with heavy plastic13 sheeting13 Bubbling Ponds Fish13

Hatchery maintains two narrow and deep (same dimensions as lined ponds13 Figure13 4)13 and13

three large13 shallow unlined ponds These earthen13 ponds typically have vegetation and

associated aquatic invertebrates that may better simulate natural environments by

providing cover and improved food diversity or quality Therefore these unlined ponds

may be expected to produce higher growth rates and potentially improved survival that is

more similar to growth rates observed in more natural grow-shy‐out facilities13 Historically13 the13

large13 shallow13 ponds have produced very large fish when13 utilized at low13 fish density13 The

narrow13 deep earthen13 ponds are13 used to grow13 fry13 at high density in their first13 year of life

The major downside to unlined ponds is the difficulty in harvesting fish where a lined

pond might take 8-shy‐1013 people13 a half13 day13 to13 harvest13 lined13 ponds13 require13 intensive13 weeding13

to allow seines to be pulled and therefore require many more personnel-shy‐hours13 In addition13

to harvest challenges the shallow earthen ponds tend to suffer from13 dissolved oxygen

crashes during the summer Unlined ponds also may maintain higher13 populations13 of non-shy‐

target species such as bluegill sunfish mosquito fish and bullfrog tadpoles We measured

growth rates of suckers in a large shallow earthen pond for comparison to growth in lined

ponds13

Figure13 4 Lined13 and13 earthen ponds13 of similar dimensions (approx 1000000 gallons first

and second panels) and a large13 shallow13 earthen13 pond (third panel)

38

13

Effect of sorting on growth

Razorback13 suckers13 are13 currently13 sorted13 after their first13 year of growth13 They are13

typically removed from13 one of the13 upper earthen13 ponds and13 split into13 two13 lined13 ponds for

subsequent grow-shy‐out13 The larger13 fish (gt approximately 140 mm) are placed into one pond

and the smaller individuals in another It is possible that the larger fish were more

aggressive or adept13 at taking food so this sorting process is intended to allow smaller fish

to improve their growth rate

Effect of Ich on razorback sucker growth rates

We13 evaluated13 growth13 rates13 of razorback sucker13 in the13 presence13 and absence of the

ectoparasite13 Ich (Ichthiopthirus multifiliis) Ich outbreaks can occur in wild populations13 but

hatcheries13 have13 proven excellent locations13 for Ich because13 of very high fish densities13 which13

facilitate13 the13 transfer13 of Ich13 between13 fish This common fish parasite causes direct mortality13

to razorback13 suckers as well13 as secondary bacterial13 infections13

The open spring and13 ditch13 which13 provides water to the Bubbling13 Ponds Hatchery

has long13 been infested with mosquitofish (Gambusia affinis) that harbor13 the13 Ich parasite13

and allow13 it13 to enter the hatchery with incoming13 water13 The solution13 to13 the13 Ich problem13

was to remove the mosquitofish host using13 Rotenone Razorback13 sucker growth13 rates were13

then tracked in13 the absence of this parasite for 4 months and compared with growth rates

after Ich returned to the pond and from13 previous years

Methods

Razorback growth rate in lined ponds

On May 14 2008 141 razorback suckers were tagged with 12 mm PIT tags (1342

kHz) and placed in Pond 3 (approximately 1100000 gallons13 Figure13 4)13 at Bubbling13 Ponds

Fish Hatchery Fifty-shy‐three of these tags were recovered two months later when a large

Ichthyophthirius multifilis (Ich) outbreak killed many fish in the pond On October 15 2008

an additional13 145 PIT tagged13 fish were13 also placed into Pond13 3 On13 May13 14 2009 Pond13 3

was harvested and a total13 of 141 PIT tagged fish were recovered13 Of the tagged fish13 26 fish

had13 been13 in the13 pond since May13 of 2008 (378 days13 o growth) and 115 had been13 in13 the

39

13 40

pond since October13 15 2008 (211 days13 of growth) Numbers of fish in Pond 3 after the Ich

outbreak and for the majority of the period of growth were between 3 000 and 4000 fish

A Hobotempreg temperature13 logger13 was13 also13 installed13 in Pond 3 one meter below the water

surface13 near13 the13 outflow and13 recorded water temperature every 3 hours to allow analysis

of the effects of water temperature on growth rate (Figure13 5) This Hobotemp data is

representative of other pond temperatures throughout this study

In a second experiment 210 adult13 razorback suckers13 were13 PIT tagged13 on13 May 14

2009 and13 placed13 into13 Pond13 3 upper to13 evaluate13 growth13 rates13 of larger13 razorback suckers13 at

Bubbling13 Ponds Hatchery13 under current13 rearing13 conditions13 Size of these fish at tagging13

was (mean = 285 mm range = 205 ndash 396 mm) These fish remained in the pond for 257

days and were harvested on Jan 25 2010 to provide information on growth rates of larger

razorback suckers13 under13 current rearing conditions

Figure 513 Temperatures (degC) inrearing pond at BubblingPonds Hatchery from July toSept 2009 (top graph)13 andfrom Nov to Dec 2009 (Lowergraph) Temperaturesrecorded with a Hobotempregremote data logger13 every 3hours

13

Growth rate13 in an unlined pond

To document razorback sucker growth in earthen ponds we introduced13 225 tagged13

razorback suckers13 into13 Pond13 1 lower13 (Figure 4) in February 3 2010 Additional tagged fish

from13 other studies were added to the pond throughout the growing season and the density

of 1 lower reached a maximum13 of nearly 7000 fish in early summer 2010 Density was

reduced to approximately 6000 fish by capturing fish with hoop nets on June 3 2010 54 of

these fish were tagged fish and returned to 1 lower after being weighed and measured The

pond was harvested on January13 2713 2011 and a total13 of 254 tagged fish out13 of 4296 fish

total were removed from13 the pond The pond was harvested on January 27 2011 (358 days13

of growth) and the tagged fish were weighed and measured Total number of razorbacks in

the pond at harvest13 was 4296

Effect of sorting practices on growth rates

On March 1113 200913 Pond13 5 upper was13 harvested13 and13 split into13 two13 separate13 groups

Two hundred of the smaller fish (average size = 122 mm TL) were PIT tagged and placed

into13 Pond13 7 upper and13 200 of the13 larger13 fish (average = 160 mm TL) were PIT tagged and

placed int Pond13 8 upper Density13 in Pond13 7 was13 4500 fish and13 in Pond13 8 there13 were13 6500

fish These ponds were then harvested after 1 year and growth rates were compared to

give information on the effects of current sorting practices Hobotempreg temperature

loggers were installed in13 Ponds 7 and13 8 during13 the13 grow-shy‐out period with13 water13

temperature recorded every 2 hours13 (Figure13 6)

Effect of Ich on razorback sucker growth rates

Bubbling Ponds spring was treated with Rotenone (CFT Legumine 5) at a

concentration of 2 ppm13 to remove all mosquitofish from13 the spring The treatment

consisted of two treatments 6 hours in duration on two consecutive days (April 12 -shy‐ 13)

using13 drip13 stations13 and13 backpack sprayers13 followed13 by13 an13 additional 6 hours13 of

detoxification using sodium13 permanganate Although 12 mosquitofish were captured in the

spring pond the week following the treatments subsequent minnow trapping (20 traps

checked13 daily13 for 3 weeks) did not capture any additional fish until August 11 2010 when

41

13

juvenile mosquitofish were again detected in the spring pond Minnow traps have

subsequently been set daily with several hundred individuals removed To evaluate if Ich

was also again present in the spring we captured 15 mosquitofish from13 the spring pond on

three separate days and placed them13 in an aquaria at 25 degC with 5 longfin dace known to be

free of Ich These fish were monitored for 2 weeks with no signs of Ich developing This

indicates that even though mosquitofish have returned to the spring pond the parasite is no

longer present13 although how13 long13 this condition13 will13 persist13 is unknown13

On May 1113 201013 200 juvenile razorback13 suckers were harvested out13 of Pond 5

upper (2009 year Class from13 Dexter National Fish Hatchery) and were PIT tagged and

placed into Pond 8 to evaluate if growth rates at bubbling ponds hatchery have improved

following the renovation of the spring and the removal of the Ich parasite Unfortunately13

on Sept13 8 2010 Ich was13 again13 detected13 in Pond 8 and the pond was immediately seined

and 74 tagged fish were measured to obtain growth information for the 4-shy‐month period

during13 which13 the13 pond13 was13 Ich-shy‐free13

Figure13 6 Temperatures (degC) in rearingponds 7 and 8 at Bubbling Ponds Hatchery13 from March 2009 ndash March 201013 pond 7(top13 graph)13 and13 pond 8 (Lower13 graph)13 Temperatures recorded with a Hobotempregremote data logger every 3 hours

42

13

Results

Growth in Lined Ponds

Razorback suckers13 that had been13 in13 Pond 8 upper for the13 entire13 year13 grew an13

average of 0263 mmday (789 mmmonth) and razorback suckers that had been in the

pond for 7 months (Oct -shy‐ May) grew13 on13 average of 028 mmday (843 mmmonth) (Figure13

7) These growth13 rates13 did not significantly13 differ Fish density13 in Pond 3 during13 the13

majority of the growth period was13 00032 ndash 00036 fishgallon13 Additionally no13 significant

differences in growth rate were observed between fish smaller than 210 mm TL and fish

larger than 210 mm TL when all recaptured fish were combined

We also measured the growth rate of very large fish in a lined pond On Jan13 2513 201013

156 adult fish with PIT tags were recovered from13 Pond 3 upper13 These fish were13 in the13

pond for 257 days and experienced an average13 growth13 rate13 of 024mmday or 73

mmmonth (Figure13 7)13 This growth13 rate13 is slightly13 lower13 than13 the13 average13 growth13 rate13

observed13 at Bubbling13 Ponds Hatchery in other studies (0275 mmday 825 mmmonth)

but may not be biologically meaningful We would expect larger13 fish to13 have13 reduced

growth rates according to a typical Von Bertalanfy growth model (Bertalanffy 1957) but it

appears that13 over the size range we evaluated (300 -shy‐ 450 mm TL) growth rates have not

slowed significantly compared to that of smaller13 fish grown at Bubbling Ponds13 Hatchery

Growth13 of razorback suckers13 is known13 to13 slow as13 fish reach13 larger13 sizes but it appears13 this13

reduced growth rate may not really start to be biologically meaningful at Bubbling Ponds

Hatchery13 until razorback suckers13 exceed 450 mm TL

Growth in unlined ponds

Growth13 rates13 for the13 fish recaptured13 during13 the Pond 1 lower13 thinning13 (120 days13 in

the pond) was 024 plusmn 003 mmday (729 plusmn 090 mmmonth) (Figure13 8)13 Fish13 that were13 in

the pond for nearly the entire year grew13 an13 average13 of 024 plusmn 001 mmday (726 plusmn 027

mmmonth) These growth rates are surprisingly the lowest measured growth rates for

any part of our study and differ significantly from13 every other measured growth rate

except very large13 fish (Figure13 9)13 Separating13 out13 large fish that13 were in13 the pond for the

entire year makes no difference fish that were added to the pond at TL lt300 mm grew

43

13

Gro

wth

Rat

e (m

md

ay)

020

026

032

0244 plusmn 001 mmday (733 plusmn 028 mmmonth) and and those with TL gt= 300 mm at the

start of the experiment grew 022 plusmn 003 mmday (651 plusmn 101 mmmonth)

Razorback Growth Rates in Lined Ponds

Figure 7 Growth ofrazorback suckers in(mmday plusmn standard error)in Pond 8 upper in 2008-shy‐2009 An ANOVA did notdetect any significantdifferences

7 Months Full Year 300+ mm fish

Effects of sorting on growth

One hundred and seventy five tagged razorback suckers were recovered from13 Pond

8 upper13 on March13 24 2010 (378 days13 of growth)13 These were13 the13 larger sorted13 fish (gt140

mm TL) that came out of Pond13 5 on March13 11 2009 One13 hundred and13 twenty13 two13 tagged13

razorback suckers were also recovered from13 Pond13 7 upper on March13 31 2010 (385 days13 of

growth)13 These were13 the13 smaller sorted13 fish (lt140 mm TL) that came out of Pond13 5 on

March 1113 200913 No significant differences in growth rate (mmday) were observed among

larger fish in Pond 8 and smaller fish in Pond 7 (pgt005 ANOVA) (Figure 10)13 indicating

that13 sorting may have helped to offset the original slower growth trajectory of the smaller

fish Temperatures of Ponds 7 and 8 upper remained similar throughout the year13 (Figure

5)

44

13

13

13

Gro

wth

Rat

e (m

md

ay)

Gro

wth

Rat

e (m

md

ay)

020

026

032

020

026

032

Razorback Growth in an Unlined Pond

Figure 8 Growth of razorbacksuckers (mmday plusmn standard error) in Pond 1 lower (an unlined pond)in 2010-shy‐2011 An ANOVA did notdetect any significant differences

6 Months 12 Months lt 300 mm Fish 300+ mm Fish Growth Growth

Lined vs Earthen Ponds 1 year of growth

Figure 9 Growth of razorbacksuckers (mmday plusmn standard error) in lined and unlined ponds A t-shy‐test13 did not detect a significantdifference

Lined Pond Unlined Pond 1 Yr Growth 1 Yr Growth

45

13

Effect of Sorting G

row

th R

ate

(mm

day

) G

row

th R

ate

(mm

day

)

032

020

026

032

020

026

Smaller Fish Larger Fish

Effect of Ich

Figure 10 Average growthof razorback suckers(mmday plusmn standard error)that were size-shy‐sorted intosmall fish (pond 7) and largefish (pond 8) populations At-shy‐test did not detect asignificant difference

Figure 11 Average growth ofrazorback suckers (mmday plusmnstandard error) after Ich wasremovd from the hatcheryrsquos springand after Ich was again detected inthe pond The growth rate withoutIch is significantly higher than boththe rate after Ich and the ourstudyrsquos average annual growth ratein lined ponds (ANOVA p =00003)

Growth without Ich Growth With Ich Average Annual 4 months 4 months Growth Rate

46

13

Effect of Ich on razorback sucker growth rates

Seventy-shy‐four13 tagged13 razorback suckers13 were13 recovered from13 Pond 8 on September

15 2010 These fish had13 been13 in the pond for 4 months and experienced a growth rate of

032 mmday or 97 mmmonth (Figure13 11)13 This growth13 rate13 is significantly higher (p =

005 two sample t-shy‐test) than the mean growth rate for the same group13 of tagged fish after

Ich detection (022 mmday or 65 mmmonth) and significantly higher than any other

individual growth13 rates13 observed13 to13 date13 at Bubbling13 Ponds Hatchery13 (Figure13 11)13 If this13

growth13 rate13 were13 extended throughout13 the entire13 year13 fish on average from13 Ich-shy‐free13 ponds13

would be 16 mm longer than fish from13 ponds infested with Ich Studies conducted at

Bubbling Ponds hatchery in 2008 (Ward 2008) did not reveal any effects of the treatment

chemicals on razorback sucker growth rates so it13 is likely that13 the parasite outbreaks

themselves are causing reducing growth rates rather than the chemicals used to treat the

parasites13

Conclusions

Our results suggest that under typical hatchery operations (maximizing number of

fish produced)13 the growth13 rate13 of razorback13 suckers13 is relatively13 consistent at Bubbling13

Ponds hatchery13 at 02-shy‐03 mmday (6-shy‐9 mmmonth)13 but is lower than growth13 rates13 at

other13 facilities (02 ndash 18 mmday Ward et al 2007)13 This growth13 rate13 has13 been13 constant in

both lined and unlined ponds and at all fish densities we were able to measure To achieve13

growth13 rates13 substantially higher than this will likely require13 significant changes in rearing

practices that may not be practical in order to reach numerical production13 goals

Temperature is a key variable in fish growth but seasonal growth patterns

described13 above13 (Figure13 5) demonstrate that water temperatures are high enough in

winter to maintain razorback growth Differences in water temperature by season

currently13 do not fluctuate more than 10degC at Bubbling Ponds because of the continuous

supply of water flowing through each pond (approx 225 gallonsmin) These high water

flows appear to keep pond temperatures within the thermal preference13 for razorback

suckers13 (1213 -shy‐ 28 degC Bulkley and Pimentel 1983) throughout the entire year with

temperatures rarely dropping13 below 16deg13 C (Figures 513 6)13

47

13

Fish density is another key variable in fish growth and though the number of fish in

a pond during our study ranged from13 3000 to 700013 fish we13 did not find any13 correlation13

between13 density and growth rate13 This might yield two conclusions First13 razorback

growth13 may be changed equally13 by13 densities13 at the13 hatchery13 (ie13 a density13 of 3000 fish in a

pond is as stressful13 for razorbacks as a density13 of 7000 fish) An alternative is that other

factors13 such as disease outbreaks have13 stronger13 control over fish growth13 than13 density13

Fish density13 would13 have13 to13 be13 experimentally manipulated to test13 this13 and hatchery

operations (producing the maximum13 number of fish) prevented our manipulating density13

in ponds for this13 work The trouble with manipulating density demonstrates the difficulties

associated with changing13 hatchery13 practices experimenting with density would have

prevented BPH from13 meeting13 production13 goals Given that the stocking of smaller

razorbacks has met with very little success perhaps BPH goals could be changed from13

producing 12000 fish at 300+ mm per year to a smaller number of very large fish each

year Growing13 fewer13 larger13 fish could potentially be accomplished in the same time frame

as more smaller fish but a better understanding of how density alters growth rate would

be required to be confident13 of this

The very slow growth13 in the13 earthen13 unlined13 Pond 1 lower13 was very surprising We13

had13 anticipated13 that the13 diversified diet13 cover and13 other13 habitat features13 provided by13

unlined ponds would yield dramatically increased growth rates However these traits were

not enough to offset high fish densities and in fact the unlined pond in our study13 suffered

mortality to bring densities down to that observed normally in lined ponds

Our data13 suggest13 that razorbacks13 sucker13 growth13 rates13 are13 higher in lined13 ponds13

However we13 think the reasons13 for the13 very slow growth we observed13 in the13 unlined13 pond13

in our study13 is instead13 linked13 to13 the13 usage13 of Pond 1 lower13 during13 the13 study13 rather13 than13

intrinsic13 slow growth13 in earthen13 ponds First the pond was at extremely high density for at

least part of the study The volume of Pond 1 lower has not been estimated but hatchery

managers suggest 1500-shy‐2000 fish is an appropriate number of individuals so this pond

was at a very high density for much of the experiment Second dissolved oxygen is often

very low in the13 large13 earthen13 ponds during the heat of summer much lower than that of

lined ponds This will both limit the number of fish that can survive in the pond and almost

certainly13 increases stress13 of these13 fish potentially13 reducing growth13 The DO crashes also13

48

13

limit the amount of feed hatchery managers can give fish in these ponds sometimes for

days or weeks at a time which further reduces growth during warm13 weather

Our data13 suggests that13 growth rates at the Bubbling13 Ponds Fish Hatchery are likely

as high as possible given13 the pond densities required to meet production goals and the Ich-shy‐

infested water that feeds the facility Sorting practices are successful in helping as many

fish as possible reach stocking length as fast as possible Unlined ponds may be able to

grow13 large13 fish at low13 densities13 but whatever factors allow13 for that13 growth are not13 able to

overcome high fish density The removal of invasive13 fis that act as13 a host for the13 parasite13

Ich fish from13 the Bubbling13 Ponds spring13 allowed the highest13 growth rate at 032 mmday13

(96 mmmonth) but that growth rate decreased again as Ich re-shy‐infested13 the13 hatchery13

Consistently13 achieving13 growth13 rates13 as high or substantially13 higher than13 this13 will likely13

require13 significant changes in rearing practices that may not be practical in order to13 reach13

numerical production13 goals

Two major changes that might result in higher growth rates are substantially

reducing fish density and modifying the way spring water is delivered to the facility (via

either repeated chemical treatments or enclosed concrete water diversions) to eliminate

Ich from13 the hatchery source water Other potential changes not address by our work

include13 flow-shy‐training razorbacks much previous literature including MSCP-shy‐funded13 work

on razorback suckers13 suggests13 that fish growing13 in flowing water will grow13 faster than fish

in still water (Jorgensen and Jobling 1994) Furthermore there are a wide variety of

potential benefits associated with growing13 fish13 in flowing13 water in addition13 to increased

growth13 rates13 (Davidson13 199713 Castro13 et al13 2011) Another option13 for increasing13 growth13

rates13 include13 changing to13 intensive13 culture13 in large circular13 tanks

Finally given that the stocking of smaller razorbacks has met with very little

success13 perhaps13 BPH13 goals13 could13 be13 changed from13 producing 12000 fish at 300+ mm per

year to a smaller number of very large fish each year Growing fewer larger fish could

potentially be accomplished in the same time frame as more smaller fish but a better

understanding13 of how density13 alters growth13 rate13 would13 be13 required to13 be13 confident of this

49

13

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower13 Colorado13 River Multi-shy‐Species13

Conservation Program13 (LCRMSCP) under Work Task C10 We13 thank Ty Wolters13 Tom13

Burke13 and Eric13 Volkman for their support of this research and Frank Agygos and Dave

Billingsly13 of the Bubbling13 Ponds Fish Hatchery13 for their willingness to participate in13 this

research13 and13 for their technical assistance We also thank the LCRMSCP fish group from13

Boulder City13 NV for their assistance with harvesting13 ponds and tagging13 fish13

50

13

Literature13 CitedAnders P J 1998 Conservation aquaculture and endangered species can objective science13

prevail13 over risk13 anxiety Fisheries 23(11) 28-shy‐31

Anderson R O and R M Nuemann 1996 Length weight and associated structural indicesPages 447 ndash 482 in B R Murphy13 and D13 W Willis13 editors13 Fisheries techniques13 2ndedtion American Fisheries13 Society13 Bethesda13 Maryland

Bain M B J T Finn and H E Brooks 1988 Streamflow regulation and fish communitystructure13 Ecology13 69382-shy‐392

Bays J H Zarbock R Whitman and T Murphy 2005 Conceptual design and managementof native13 fish refugia on the13 lower13 Colorado13 River In13 CL Spring13 and13 S Leoneditors Proceedings of two symposia Restoring native fish to the lower ColoradoRiver13 interactions13 of native and non-shy‐native13 fishes 13ndash1413 July13 1999 Las13 Vegas13 Nevada13 Restoring13 natural function within a modified riverine environment thelower Colorado River13 8ndash913 July13 1998 U S Fish and13 Wildlife13 Service Southwestern13 Region Albuquerque New Mexico Pages 167-shy‐177

Bertalanffy L Von 1957 Quantitative laws in metabolism13 and growth13 Q Rev Biology 32217 ndash 231

Bingham T B Scheer and C McAda 2003 Propagation facilities in Grand Valley (24 RoadHatchery Horsethief13 Ponds and13 grow-shy‐out ponds) for captive13 rearing13 ofendangered13 fishes for the13 upper13 Colorado13 River basin13 Colorado River RecoveryProgram FY2003 annual project report13 US Fish and13 Wildlife13 Service GrandJunction13 4pp

Birchell G J and K Christopherson 2004 Survival growth and recruitment of larval andjuvenile razorback13 sucker (Xyrauchen texanus) introduced13 into13 floodplain13 depressions13 of the13 Green River Utah13 Final report13 Upper13 Colorado13 RiverEndangered Fish Recovery Program13 Project No C-shy‐6RZ Publication Number 04-shy‐1513 Utah13 Division of Wildlife13 Resources Salt Lake13 City13 Utah13 67 pages

Brannon E L 1993 The perpetual oversight of hatchery programs Fishery Research 1819-shy‐27

Brett J R 1979 Environmental Factors and growth pages 599-shy‐67513 InW S Hoar13 D13 J13 Randall and J R Brett (eds) Fish Physiology Volume 8 Bioenergetics and GrowthAcademic Press New York

Brooks J E 1986 Annual reintroduction and monitoring report for razorback suckerXyrauchen texanus in the Gila River Basin Arizona 1985 US Fish and WildlifeService13 Offices of Endangered13 Species and Fishery13 Resources Albuquerque 23 pp

51

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Brunson13 R E and K D13 Christopherson13 200513 Larval13 razorback13 sucker and bonytailsurvival and13 growth13 in the13 presence13 of nonnative13 fish in the13 Baeser13 floodplainwetland of the middle Green River Final report prepared for Upper13 Colorado RiverBasin Endangered Fish Recovery Program Project No C-shy‐6-shy‐rz-shy‐bt Publication13 No 05-shy‐26 Utah13 Division of Wildlife13 Resources13 Vernal13 32 pp

Bulkley R V and R Pimentel 1983 Temperature preference and avoidance by adultrazorback suckers Transactions of the American Fisheries Society 112601-shy‐607

Burke13 T13 199513 Rearing13 wild razorback13 sucker larvae in13 lake-shy‐side13 backwaters13 LakeMohave ArizonaNevada Proceedings of the Desert Fishes Council 2635

Busacker G P I R Adelman and E M Goolish13 199013 Growth13 Pages 363 ndash 387 in C BSchreck and p B Moyle editors Methods for fish biology American FisheriesSociety Bethesda Maryland

Castro V B Grisdale-shy‐Helland S J Helland T Kristensen S M Jorgensen J Helgrud13 GClaireaux A P Farrell A Krasnov and H Takle 2011 Aerobic training stimulatesgrowth and promotes disease resistance in Atlantic salmon (Salmo salar)Comparative Biochemistry and Physiology -shy‐ Part A Molecular amp IntegrativePhysiology13 160(2) 278-shy‐290

Czapla T E 2002 Facilities plan for the production of endangered fishes to meet statestocking13 plans13 as13 part of the13 Upper13 Colorado13 River Endangered13 Fish RecoveryProgram Upper Colorado River Basin Recovery Implementation Program US Fishand Wildlife Service13 Denver13 9 pp

Davidson W 1997 The effects13 of exercise13 training on teleost fish a review of recentliterature Comput Biochem Physiol 117A67ndash75

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Hamman R L 1985 Induced spawning of hatchery-shy‐reared13 razorback sucker ProgressivFish Culturist 47(3) 187-shy‐189

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Kaeding L R and D B Osmundson 198913 Colorado13 Squawfish13 and13 razorback sucker grow-shy‐out pond studies as part of conservation measures for the green mountain andRuedi reservoir water sales Final report for agreement number 6-shy‐AA-shy‐60-shy‐00150

Koebele13 B P13 198513 Growth and the size hierarchy effect an experimental assessment ofthree proposed mechanisms activity differences disproportional food acquisition13 pysiological stress Environmental Biology of Fishes 12 181-shy‐188

Kretschmann A E and L L Leslie 2006 Razorback sucker (Xyrauchen texanus) status13 reproduction and recruitment in Senator Wash Reservoir CA Final Report13 to USBurea of Reclamation Cooperative Agreement No 00-shy‐FG-shy‐34-shy‐ 0009 p 32 ArizonaGame and Fish Department Phoenix

Marsh13 P13 C13 1987a13 Digestive tract13 contents13 of adult razorback suckers13 in Lake13 MohaveArizona-shy‐Nevada Transactions of the American Fisheries Society 116117-shy‐119

Marsh P C 1987b Native fishes at Buenos Aires National Wildlife Refuge and ArizonaState University Research Park Arizona opportunities for management researchand public13 education13 on13 endangered species13 Proceedings of the Desert13 FishesCouncil 1967-shy‐78

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Marsh P C B R Kesner and C A Pacey 2005 Repatriation as s management strategy13 to13 conserve a critically13 imperiled fish species North American Journal of FisheriesManagement 25 547-shy‐556

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Marsh13 P13 C13 and J13 E Brooks13 198913 Predation13 by ictalurid catfishes as a deterrent13 toreestablishment of hatchery-shy‐reared13 razorback sucker The Southwestern Naturalist34188-shy‐195

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Minckley13 W L13 199113 Native fished of the Grand Canyon13 region an obituary13 Pages 124-shy‐177 in Colorado River ecology and dam13 management National Academy PressWashington13 DC

Minckley13 C13 O and M LaBarbara13 199913 Report13 on13 native fish grow-shy‐out facilities13 at Cibolaand Imperial National Wildlife Refuges 1993-shy‐199513 US Fish and13 Wildlife Service13 Parker Fishery Resources Office Parker Arizona

Modde13 T13 199613 Juvenile razorback sucker (Xyrauchen texanus) in a managed wetlandadjacent13 to the Green13 River13 Great13 Basin13 Naturalist13 56375-shy‐376

Modde T KP Burnham and E J Wick 1996 Population status of the razorback sucker13 inthe middle Green River (USA) Conservation13 biology 10 110-shy‐119

Modde13 T13 and G13 B Haines13 200513 Survival13 and growth of stocked razorback13 sucker andbonytail in multiple floodplain wetlands of the middle Green River under resetconditions13 Final report prepared for Upper Colorado13 River13 Basin RecoveryImplimentation Program US Fish and Wildlife Service Vernal 66 pp

54

13

Modde T Z H Bowen and D C Kitcheyan 2005 Spatial and temporal use of a spawning13 site in the middle Green River by wild hatchery-shy‐reared13 razorback suckers13 Transactions of the American Fisheries Society 134937-shy‐944

Mueller13 G13 199213 The native fish work13 group13 -shy‐ a multiagency endeavor to improve thestatus of the razorback sucker in Lake Mohave AZ-shy‐NV13 Proceedings of the DesertFishes Council 2369

Mueller G 1995 A program13 for maintaining the razorback sucker in Lake MohaveAmerican Fisheries Society Symposium 15127-shy‐135

Mueller13 G13 200613 Ecology of the bonytail13 and razorback13 sucker and the role of offchannelhabitats13 in their13 recovery Scientific13 investigations13 report 2006-shy‐5065 US GeologicalSurvey13 Denver

Mueller G and E Wick 1998 Testing of golf course ponds at Page Arizona for suitability13 as grow-shy‐out facility for razorback sucker using surplus fish from13 Ouray NationalFish Hatchery National Park Service US Fish and13 Wildlife13 Service and UtahDivision of Wildlife13 Resources 28 pages

Mueller13 G13 and T13 Burke13 200513 Survival13 of young13 razorback13 sucker (Xyrauchen texanus) inrelation to13 stocking rates13 (fishha)13 and13 in the presence13 or absence13 of predatorcommunities in Lake Mohave Arizona-shy‐Nevada13 Pages13 155-shy‐16313 in Proceedings of two13 symposia restoring native fish to the lower Colorado River interaction13 of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 Nevada US Fish and Wildlife13 Service Southwest Region Albuquerque New Mexico

Mueller13 G13 J13 Carpenter13 and P13 C13 Marsh13 200413 Cibola13 High Levee Pond annual report 2004US Geological Survey Fort Collins13 Science Center13 Colorado13 and Arizona StateUniversity Tempe 23 pages

Nesler T P K Christopherson J M Hudson C W McAda F Pfeifer and T E Czapla 2003An integrated stocking plan for razorback sucker bonytail and Colorado13 pikeminnow for the Upper Colorado River Endangered Fish Recovery ProgramAddendum13 to State Stocking Plans Upper Colorado River Basin Recovery13 Implementation Program 12 pp

Papoulias13 D and W13 L Minckley13 1992 Effects13 of foo availability13 on survival and growth13 of larval razorback suckers13 in ponds Transactions of the American Fisheries Society121340-shy‐355

Paukert13 C P D L Ward13 P J Sponholtz13 and K13 D Hilwig13 Effects13 of repeated hoopnetting13 on bonytail chub13 Journal of Freshwater13 Ecology13 20(4) 649-shy‐653

Pfeifer F M13 C Baker13 and M13 Montagne13 199913 Propagation13 facilities13 in the13 Grand Valley13 (24 Road13 Hatchery13 Horsethief13 Ponds and13 grow-shy‐out ponds) for captive rearing of

55

13

endangered13 fishes for the13 Upper Colorado13 River Basin13 Colorado13 River Recovery13 Program FY 99 annual project report Project No 29a13 US Fish and Wildlife Service13 Grand13 Junction13 5pp

Pfeifer F S Seversen and M Montagne 2003 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2003 annual reportProject No 29b13 US Fish and Wildlife13 Service Vernal13 4pp

Rabago-shy‐Castro J L Sanchez13 J G Perez-shy‐Castaneda R and13 Gonzalez-shy‐Gonzlez A 2006Effects of the prophylactic use of Romet-shy‐3013 and13 copper13 sulfate13 on growth13 condition13 and feeding13 indicies in13 channel13 catfish (Ictalurus punctatus) Aquaculture 253 343-shy‐349

Reinitz GL L E Orme and F N Hitzel 1979 Variations of body compositio and growth13 among strains of rainbow trout Transactions of the American Fisheries Society 108204-shy‐207

Ruppert13 J13 B P B Holden13 and P D Abate 1999 Age estimation and growth of razorbacksucker13 Xyrauchen texanus in Lake13 Mead Nevada Proceedings13 of the Desert FishesCouncil 3040

Schnoor K D and J Logan 2002 Operation and maintenance of JW Mumma nativeaquatic13 species restoration facility Colorado Colorado River Recovery Program FY2002 annual project report13 Project No 29d Colorado13 Division of Wildlife Alamosa3pp

Salisbury13 L13 1998 Factors13 affecting razorback13 sucker growth13 in Lake13 Mohave backwaters13 MS Thesis13 Unviersity13 of Nevada13 Las13 Vegas

Schooley J13 D13 and P C13 Marsh13 2007 Stocking of endangerdd13 razorback13 suckers13 in thelower Colorado River Basin13 over three decades 1974-shy‐2004 North American Journalof Fisheries Management 27 43-shy‐51

Severson S H H M Tyus and G B Haines 1992 An evaluation of feeds for raisingrazorback sucker Xyrauchen texanus Journal of Applied Aquaculture 155-shy‐65

Toney D P 1974 Observations13 on the13 propagation13 and13 rearing13 of two13 endangered species13 in a hatchery environment Proceedings of the Annual Conference of the Western13 Association of State Game and Fish Commissions 54 252-shy‐259

Tyus H M13 1998 Razorback sucker13 (Xyrauchen texanus) recovery plan13 University13 ofColorado Center for Limnology Boulder13 76 pages

Tyus H M13 and13 S H Severson 1990 Growth13 and13 survival of larval razorback suckers fedfive formulated diets The Progressive Fish Culturist 52197-shy‐200

56

13

Ulibarri M E 2003 Annual report fiscal year 2001 Dexter National Fish Hatchery13 andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 26 pages

Ulibarri M E 2003 Annual report fiscal year 2002 Dexter National Fish Hatchery andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 59 pages

USBR 2006 Lower13 Colorado13 River Multi-shy‐Species Conservation Program final fishaugmentation plan Boulder City 19 pp

USFWS 2002 Razorback sucker (Xyraouchen texanus) recovery goals Amendment andsupplement to the Razorback Sucker Recovery Plan13 US Fish and Wildlife Service13 Region 6 Denver13 Colorado

USFWS 1999 Annual report 1999 Ouray National Fish Hatchery Vernal 25pp

USFWS 2004 Management plan for the big-shy‐river13 fishes of the13 lower13 Colorado13 river basinamendment and supplement to the bonytail humpback chub Coloradopikeminnow and razorback sucker recovery plans

USFWS13 2005 Station13 profile13 of the13 Dexter13 National Fish Hatchery13 and Technology CenterUS Fish and Wildlife13 Service Dexter

Valdez R A P G Mangan R Smith and B Nilson 1982 Upper Colorado River fisheriesinvestigations13 inW H Miller J J Valentine D L Archer H M Tyus R A Valdezand L13 Kaeding13 editors13 Colorado River Fishery13 Project13 Part 2 Field13 investigations13 US Bureau of Reclamation Salt Lake City Utah

WBNFH 2004 Culture methods of the endangered razorback sucker Xyrauchen texanusUS Fish and Wildlife13 Service Willow Beach National Fish Hatchery13 8 pp

Ward D 2008 Effects of disease treatments on growth of razorback sucker ReportSubmitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 Inpartial fulfillment of work task C10 agreement number 06FG30039

Ward13 D13 M Childs and W Persons 2007 Factors13 affecting13 growth13 of razorback sucker13 (Xyrauchen texanus) in captivity Literature review and knowledge assessmentReport Submitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 In partial fulfillment of work task C10 agreement number 06FG30039

57

Appendices

Appendix 1 Survey Questions Survey of Razorback Sucker Culture in the

Southwestern United States

The enclosed survey is being distributed by the Arizona Game and Fish Department to razorback sucker culture facilities throughout

the Southwestern United States The purpose of this survey is to consolidate information regarding culture of this species so that

appropriate facility improvements can be considered for Bubbling Ponds Hatchery in Arizona Specifically we wish to increase

growth rate and production efficiency at the hatchery Information gathered in this survey will be summarized in a final report to US

Bureau of Reclamation in Boulder City NV and disseminated to all facilities that participate in the survey A workshop to discuss

the findings of this study as well as to share general information concerning razorback sucker culture will be organized by the

Arizona Game and Fish Department at the conclusion of this study and all participants will be invited

Thank you for taking the time to fill out this survey Please contact Mike Childs if you have questions or would like to discuss the

survey

Mike Childs

mchildssedonanet

(928) 639-1346

(928) 634-1279

Facility_____________________________________ Date___________________

Contact Phone _____________________________

ContactPerson_______________________________

Contact Email _______________________________

1 Water quality ranges at this culture facility

Season

Spring (Mar-May) Summer (Jun-Aug) Fall (Sept-Nov) Winter (Dec-Feb)

Temperature (C)

PH

DO (mgL)

PO4 (mgL)

TDS (mgL)

Hardness (mgL)

CaCO3

Pathogens

37

13

II The Effect of Disease Treatments on Razorback Sucker

Growth

Section13 SummaryFormalin copper sulfate potassium permanganate and13 salt are all chemicals commonly13 used13 to13 treat13 Ichthyophthirius multifiliis outbreaks in captive razorback sucker (Xyrauchen13 texanus) Weexposed 190 juvenile13 razorback suckers (127 ndash 26 mm TL) to13 5 5-shy‐day treatments with13 each13 chemical to evaluate the effects13 these chemicals13 may have on growth Fish grew an average of23513 mm TL13 during the month13 study period Fish treated with formalin grew on average13 29mm TL (03 mmday) while fish treated with copper had the lowest growth averaging 20 mmTL (021 mmday) No significant differences in13 growth were observed among fish treatedwith any of the chemicals compared to untreated fish (pgt005) Reductions in growth13 as aresult of repeated chemical treatments are not likely the cause of differences in growth ratesamong13 facilities that raise razorback suckers Repeated chemical treatments may13 have otherimpacts to overall13 fitness or long-shy‐term survival but13 these effects were not13 evident13 in our study

29

13

Introduction

Preservation13 of razorback sucker13 (Xyrauchen texanus) currently13 depends on captive13

rearing and stocking programs until permanent solutions to factors that prevent wild13

recruitment are found Low survival of stocked razorback suckers (Brooks 1986 Marsh

and Brooks 198913 Marsh and Pacey13 2005) has caused target13 sizes for stocked fish to

steadily increase in efforts to reduce predation mortality (Marsh et al 2005 Schooley and

Marsh 2007) Rearing fish to larger sizes at hatcheries comes with increased costs and

creates the need to evaluate husbandry and rearing practices that may affect fish growth

Formalin copper sulfate potassium13 permanganate and salt are all chemicals

commonly used at razorback sucker rearing facilities to treat outbreaks of the protozoan

parasite13 Ichthyophthirius multifiliis ldquoIchrdquo is one of the most pathenogenic diseases of

cultured13 freshwater13 fishes (Matthews13 2005) and causes large13 losses in captive13 populations13

of endangered razorback sucker Each of these chemicals used to treat Ich only kill the free-shy‐

swimming life stage of the parasite13 requiring13 repeated doses over several13 days depending13

on water temperature These chemicals treatments are needed to prevent loss as a result

of disease outbreaks but the cumulative effects repeated disease treatments have on

growth13 are13 unknown

Copper13 sulfate13 has13 been shown to13 significantly13 reduce13 growth13 of channel catfish13 in

production13 ponds (Rabago-shy‐Castro13 2006) but it is unknown whether13 razorback suckers13

experience similar reduced growth following copper treatment Quantifying the impacts of

disease treatments on growth will help to interpret the wide differences in growth rates

observed13 at various13 razorback sucker13 production13 facilities13 throughout the13 southwest

(Ward et al 2007) If one chemical is found to have less detrimental impacts on growth

than another then it may be preferred for use as a disease treatment We evaluated growth

rates13 of razorback suckers13 under13 replicated13 and13 controlled13 conditions13 to13 assess13 effects13 of

repeated formalin copper sulfate and potassium permanganate and salt treatments on

growth13

Methods

We captured 190 juvenile razorback suckers from13 ponds at Bubbling Ponds Fish

Hatchery AZ using hoop nets or cast nets All fish were of the same age class and

30

13

averaged 179 mm total length (TL) (range13 = 127 ndash 262 mm TL)13 These fish were13 offspring13

of captive13 razorback sucker13 broodstock held13 at Dexter13 National13 Fish Hatchery13 NM13 (2007

year class) All fish were tagged with passive integrated transponder (PIT) tags and

quarantined for one month prior to the experiment to allow fish to recover from13 tagging

and become accustomed to being held in circular tanks

At the beginning of the study all fish were weighed measured and scanned for

individual tag numbers with 19 randomly selected fish placed into each13 of 10 8-shy‐foot

diameter circular tanks (Figure 2)13 Each13 tank contained13 two13 airstones13 and13 an13 individual

biofilter with a recirculating water pump (31 litersminute) that had been operating for

at least 1 month prior to the experiment to allow bacterial colonies to become

established Two tanks were designated as a control and did not receive any chemical

treatments while the other eight tanks received formalin copper sulfate potassium13

permanganate or salt treatments at two week intervals (two tanks per chemical

treatment) Formalin copper sulfate and potassium13 permanganate were treated at 1 part

per million (ppm) and salt was applied at 30 parts per thousand (ppt) These treatment

rates are commonly used to treat13 razorback13 suckers for ich at Bubbling13 Ponds Fish13

hatchery (Frank Agygos personal communication)

Figure 213 Photo ofexperimental tankswith individualbiofilters and aeration

31

13

Each treatment consisted of a series of doses applied on Wednesday Thursday and

Friday with a 90water change between each dose Biofilters were removed from13 all

tanks and held in a separate holding facility during treatments and then replaced on the

Monday following treatments after a 90water change This schedule allowed fish to be

exposed to chemical treatments for 5 consecutive days without water quality deteriorating

This 5-shy‐day chemical treatment was repeated every two weeks from13 July to October (97

days)13 for a total of 5 5-shy‐day treatments Water temperature in the treatment tanks ranged

from13 13degC (55degF) to 32degC (91degF)

Fish were fed a fixed ration of commercial razorback diet (Silvercup 4mm13 pellet)

once daily13 (2 percent body13 weight per day13 as calculated13 by13 average initial fish weight)13

At the end of the experiment all fish were again weighed measured and scanned for

individual tag numbers Growth of fish in each treatment group was compared using

analysis of variance (ANOVA) Any mortalities13 that occurred during the13 study13 were13

replaced with previously quarantined fish of equivalent size to maintain equal densities in

each13 tank13 but growth13 data was13 only13 recorded for fish which13 survived13 the13 entire13

experiment

Results

Fish at the13 start of the experiment averaged 179 mm TL (Range13 = 127 ndash 262 mm)

with no significant differences in fish length among treatment groups (F(4189) = 00183 p

gt 0999 ANOVA) On average fish grew 235 mm TL (024 mmday) during the 3 month

study13 Fish in tanks13 treated with formalin had the highest growth averaging 29 mm TL (03

mmday) while fish in tanks treated with copper had the lowest growth averaging 20 mm

TL (021 mmday) Fish in the control tanks averaged 213 mm TL in growth (022

mmday) (Figure13 3)13 Formalin-shy‐treated fish grew13 significantly faster than13 any other

treatment group but no13 significant differences in growth13 in length13 or weight were13

observed among fish treated with any of the chemicals compared to untreated (control)

fish (pgt005 ANOVA)

32

13

Figure 313 Average growthof razorback suckersexposed to a series of 5 5-shy‐day chemical treatmentsover a 97-shy‐day13 periodError bars representstandard error

Discussion13

Growth13 rates13 observed13 in our study13 (021 ndash 03 mmday) are low compared to those

reported13 in other13 studies13 of razorback sucker13 growth13 (0213 ndash 18 mmday) (Ward et al

2007) Using recirculating water systems for our study required filters to be removed and

replaced during treatments Stress to fish caused by removing and replacing filters within

the tanks as well as repeated water changes may have led to overall higher stress and

reduced growth rates compared to those reported for unconfined fish Growth in fish is

highly variable and is affected by many different physiological and environmental factors

including fish size density temperature amount of space and food (Brett 1979) We

strived to control each of these factors but other factors may have also influenced growth

in our experimental tanks During mid-shy‐summer water temperatures in the treatment

tanks reached 32degC (91degF) At these warm13 temperatures fish are very susceptible to

bacterial13 infections13 The slightly higher growth exhibited by fish in the formalin and

potassium13 permanganate treatments may have been the result of these two chemicals

33

13

being effective at controlling bacterial infections The differences in growth we measured

among treatment groups were not statistically significant and do not appear13 biologically13

meaningful during the relatively short duration of this study (97 days) although the

cumulative effects of slightly reduced growth could be biologically meaningful over longer

time frames

Reductions in growth13 as a result13 o repeated chemical treatments are not likely the

cause of differences in growth rates among facilities that raise razorback suckers

Repeated chemical treatments may have other impacts to overall fitness or long-shy‐term13

survival but these13 effects13 were13 not evident in our study It is more likely that the parasite

outbreaks themselves are the cause of different growth rates among razorback rearing

facilities rather than the chemical treatments used to treat the parasites We recommend

that hatchery managers continue to use the chemicals that are most effective at controlling

ldquoIchrdquo13 at their individual13 facilities

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower Colorado Rive Multi-shy‐species13

Conservation Plan under Work Task C10 We thank Ty Wolters and Tom13 Burke for their

support of this research and Frank Agygos and Dave Billingsly of the Bubbling Ponds Fish

Hatchery13 for their13 technical assistance13 and13 help with13 collecting13 fish

34

13

III13 Razorback Growth Rates at Bubbling Ponds ndash 2009-shy‐2011

Section13 SummaryExperimental studies at Bubbling Ponds Fish Hatchery AZ have strived to understand

factors that affect razorback sucker growth in captivity and identify ways to improve growthrates and maximize size at release Rather than performing experimental studies that wouldrequire major13 rearrangement (and likely reduced production)13 of hatchery operations our13 studies13 used normal variation in production techniques13 and practices13 to isolate factors13 thatmay modify growth rates

Our initial work identified razorback13 growth rates in13 lined ponds at standard fishdensity as 026 to13 028mmday (789 to 843 mmmonth) No significant differences in growthrate were observed among fish that had been in the pond only during the winter13 periodcompared to fish that had been in the pond the entire year indicating that water temperatures13 at Bubbling Ponds are high enough to allow fish to incorporate feed effectively year-shy‐roundHowever these growth rates are lower than most values reported from the literature fromnatural or semi-shy‐natural pond environments No significant differences in13 growth rate wereobserved13 between large and13 small fish13 within the 150 ndash 29 mm TL13 size range Additional worksuggests13 that razorback suckers13 tagged at over 300 mm TL had reduced growth rates (024mmday 73 mmmonth) as would be expected according to a typical Von13 Bertalanfy growthcurve although growth rates13 were only slightly less13 than the average growth rate for thehatchery (027513 mmday 82513 mmmonth)

Sorting13 to13 separate small fish from large fish after the first year of growth is practicedesigned13 to allow smaller fish to ldquocatch uprdquo to larger fish We found that13 this technique doesappear to13 improve growth rates of smaller fish Growth rates of sorted small razorback suckers(029 mmday 87mmmonth)13 were equal to that13 of larger13 fish (028 mmday 8413 mmmonth)indicating that sorting may have helped to offset their original slower growth trajectory

Bubbling Ponds Fish Hatchery grows razorbacks in 6 long deep ponds lined with heavyplastic 2 long deep13 earthen13 (unlined) ponds and three wide shallow earthen ponds The wideshallow ponds13 have historically produced very large fish at low density but have been found tomaintain much lower fish numbers than deeper ponds We found13 that growth13 rates ofrazorbacks kept at high density (4-shy‐700013 fish)13 in a wide shallow pond grew extremely slowly(024 mmday 726 mmmonth) This growth rate is among the slowest of any fish over theyears of our study and demonstrates that13 though the large ponds may produce large fish at lowdensity13 they are unable to overcome high13 fish13 densities

Finally one of the major factors influencing13 fish13 growth13 in hatcheries is disease onemajor summer-shy‐time disease at13 Bubbling Ponds is the ectoparasite Ich (Ichthiopthirusmultifiliis) To investigate the impact Ich has on razorback growth we eradicated fish from thespring and water conveyance ditch that supplies13 water to the hatchery using Rotenone This13 restoration effort was fairly short-shy‐lived (Ich returned to the hatchery within four months) but

35

13

growth13 rates of fish13 reared for four months without Ich present (031 mmday 92 mmmonth)were significantly higher than the following 8 months of growth for those same fish (022mmday 65 mmmonth) This disease-shy‐free growth rate is in fact faster than any13 otherprevious growth rates observed at the hatchery in our study

We conclude that growth rates at the Bubbling Ponds Fish Hatchery are likely as highas possible given the pond densities required to13 meet production goals and the Ich-shy‐infestedwater13 that feeds the facility Sorting practices are successful in helping as many fish as possiblereach stocking length as fast as possible Unlined ponds may be able to grow large fish at lowdensities but whatever factors allow for that growth13 are not able13 to overcome13 high fish densityThus the large lower ponds at Bubbling Ponds may be better utilized via renovation to13 deepenand line them

Disease is the most important factor limiting growth as may be expected to be the caseat many13 hatcheries While the spring renovation was not13 a complete success13 the dramaticreduction of fish populations in that habitat was enough to dramatically13 reduce13 the13 occurrenceof Ich at the hatchery13 Such open spring13 systems feeding a hatchery are a misfortune that canbe expected to transmit disease so we suggest that renovating the spring again to combat13 IchImproved techniques to divert water from13 the springs and more throuough treatment ofstream-shy‐side vegetation may improve the success of chemical treatment Successful renovationwould likely both improve growth rates and reduce chemical costs associated with treating Ichoutbreaks Even13 if complete renovation13 is impossible or impractical an13 effort to reduceinvasive fish density in the springs13 which act a vector for the parasite(and thereby reduce thelikelihood of13 Ich being transmitted into ponds) may still13 show dramatic improvements

36

13

Introduction

Conservation efforts13 for razorback sucker13 (Xyrauchen texanus)13 currently13 depend on

captive rearing and stocking programs Low survival of stocked razorback suckers (Brooks

1986 Marsh13 and13 Brooks13 1989 Marsh13 and13 Pacey13 2005) has13 caused13 target sizes for stocked13

fish to steadily increase in efforts to reduce predation mortality13 (Marsh13 et al13 2005

Schooley and Marsh 2007) Rearing fish to larger sizes at hatcheries comes with increased

costs and creates the need to evaluate husbandry and rearing practices that may affect fish

growth13 We evaluated growth13 rates13 of individual razorback suckers13 in ponds13 at Bubbling

Ponds Fish Hatchery13 using Passive Integrated13 Transponder (PIT) tags13 to13 obtain13 precise

growth information for individual fish so that valid comparisons of growth rates as related

to rearing practices can be made

Due to the critical nature of the razorback sucker stocking program we did not

design experimental studies that would require major rearrangement and potentially

reduce production of hatchery operations Instead our studies used normal variation in

production techniques and practices to isolate factors that may modify growth rates

Though this methodology dramatically limits replication and may limit our ability to

directly13 attribute13 differences in growth13 rates13 to13 the13 variables13 we13 investigate13 we13 were13 able13

to accomplish research goals without altering hatchery operations or impacting

production

From13 2009 through 2011 we conducted a series of observational13 growth13 studies to

determine growth rates of individual razorbacks at Bubbling Ponds The first set of

experiments included13 identifying13 growth13 rates13 in lined13 and13 unlined13 ponds determining

growth13 rates13 of fish at different13 sizes13 in13 relation13 to sorting13 practices and monitoring

razorback growth rates after removing the source of the ectoparasite13 Ich (Ichthiopthirus

multifiliis) from13 the hatchery water source13

Razorback growth rate in lined ponds

Our first growth study documented individual growth rates at normal density in 11

million gallon lined ponds13 over two13 years13 This is the standard13 grow-shy‐out process for

razorbacks13 at Bubbling Ponds We monitored growth of fish for a variety13 of sizes and13 the13

37

13

amount of time in a pond during the growing season These13 data give a snapshot of growth13

rates13 at the13 facility13 and13 provide13 the basis for comparisons throughout our study

Growth rate13 in an unlined pond

In addition13 to 6 ponds lined with heavy plastic13 sheeting13 Bubbling Ponds Fish13

Hatchery maintains two narrow and deep (same dimensions as lined ponds13 Figure13 4)13 and13

three large13 shallow unlined ponds These earthen13 ponds typically have vegetation and

associated aquatic invertebrates that may better simulate natural environments by

providing cover and improved food diversity or quality Therefore these unlined ponds

may be expected to produce higher growth rates and potentially improved survival that is

more similar to growth rates observed in more natural grow-shy‐out facilities13 Historically13 the13

large13 shallow13 ponds have produced very large fish when13 utilized at low13 fish density13 The

narrow13 deep earthen13 ponds are13 used to grow13 fry13 at high density in their first13 year of life

The major downside to unlined ponds is the difficulty in harvesting fish where a lined

pond might take 8-shy‐1013 people13 a half13 day13 to13 harvest13 lined13 ponds13 require13 intensive13 weeding13

to allow seines to be pulled and therefore require many more personnel-shy‐hours13 In addition13

to harvest challenges the shallow earthen ponds tend to suffer from13 dissolved oxygen

crashes during the summer Unlined ponds also may maintain higher13 populations13 of non-shy‐

target species such as bluegill sunfish mosquito fish and bullfrog tadpoles We measured

growth rates of suckers in a large shallow earthen pond for comparison to growth in lined

ponds13

Figure13 4 Lined13 and13 earthen ponds13 of similar dimensions (approx 1000000 gallons first

and second panels) and a large13 shallow13 earthen13 pond (third panel)

38

13

Effect of sorting on growth

Razorback13 suckers13 are13 currently13 sorted13 after their first13 year of growth13 They are13

typically removed from13 one of the13 upper earthen13 ponds and13 split into13 two13 lined13 ponds for

subsequent grow-shy‐out13 The larger13 fish (gt approximately 140 mm) are placed into one pond

and the smaller individuals in another It is possible that the larger fish were more

aggressive or adept13 at taking food so this sorting process is intended to allow smaller fish

to improve their growth rate

Effect of Ich on razorback sucker growth rates

We13 evaluated13 growth13 rates13 of razorback sucker13 in the13 presence13 and absence of the

ectoparasite13 Ich (Ichthiopthirus multifiliis) Ich outbreaks can occur in wild populations13 but

hatcheries13 have13 proven excellent locations13 for Ich because13 of very high fish densities13 which13

facilitate13 the13 transfer13 of Ich13 between13 fish This common fish parasite causes direct mortality13

to razorback13 suckers as well13 as secondary bacterial13 infections13

The open spring and13 ditch13 which13 provides water to the Bubbling13 Ponds Hatchery

has long13 been infested with mosquitofish (Gambusia affinis) that harbor13 the13 Ich parasite13

and allow13 it13 to enter the hatchery with incoming13 water13 The solution13 to13 the13 Ich problem13

was to remove the mosquitofish host using13 Rotenone Razorback13 sucker growth13 rates were13

then tracked in13 the absence of this parasite for 4 months and compared with growth rates

after Ich returned to the pond and from13 previous years

Methods

Razorback growth rate in lined ponds

On May 14 2008 141 razorback suckers were tagged with 12 mm PIT tags (1342

kHz) and placed in Pond 3 (approximately 1100000 gallons13 Figure13 4)13 at Bubbling13 Ponds

Fish Hatchery Fifty-shy‐three of these tags were recovered two months later when a large

Ichthyophthirius multifilis (Ich) outbreak killed many fish in the pond On October 15 2008

an additional13 145 PIT tagged13 fish were13 also placed into Pond13 3 On13 May13 14 2009 Pond13 3

was harvested and a total13 of 141 PIT tagged fish were recovered13 Of the tagged fish13 26 fish

had13 been13 in the13 pond since May13 of 2008 (378 days13 o growth) and 115 had been13 in13 the

39

13 40

pond since October13 15 2008 (211 days13 of growth) Numbers of fish in Pond 3 after the Ich

outbreak and for the majority of the period of growth were between 3 000 and 4000 fish

A Hobotempreg temperature13 logger13 was13 also13 installed13 in Pond 3 one meter below the water

surface13 near13 the13 outflow and13 recorded water temperature every 3 hours to allow analysis

of the effects of water temperature on growth rate (Figure13 5) This Hobotemp data is

representative of other pond temperatures throughout this study

In a second experiment 210 adult13 razorback suckers13 were13 PIT tagged13 on13 May 14

2009 and13 placed13 into13 Pond13 3 upper to13 evaluate13 growth13 rates13 of larger13 razorback suckers13 at

Bubbling13 Ponds Hatchery13 under current13 rearing13 conditions13 Size of these fish at tagging13

was (mean = 285 mm range = 205 ndash 396 mm) These fish remained in the pond for 257

days and were harvested on Jan 25 2010 to provide information on growth rates of larger

razorback suckers13 under13 current rearing conditions

Figure 513 Temperatures (degC) inrearing pond at BubblingPonds Hatchery from July toSept 2009 (top graph)13 andfrom Nov to Dec 2009 (Lowergraph) Temperaturesrecorded with a Hobotempregremote data logger13 every 3hours

13

Growth rate13 in an unlined pond

To document razorback sucker growth in earthen ponds we introduced13 225 tagged13

razorback suckers13 into13 Pond13 1 lower13 (Figure 4) in February 3 2010 Additional tagged fish

from13 other studies were added to the pond throughout the growing season and the density

of 1 lower reached a maximum13 of nearly 7000 fish in early summer 2010 Density was

reduced to approximately 6000 fish by capturing fish with hoop nets on June 3 2010 54 of

these fish were tagged fish and returned to 1 lower after being weighed and measured The

pond was harvested on January13 2713 2011 and a total13 of 254 tagged fish out13 of 4296 fish

total were removed from13 the pond The pond was harvested on January 27 2011 (358 days13

of growth) and the tagged fish were weighed and measured Total number of razorbacks in

the pond at harvest13 was 4296

Effect of sorting practices on growth rates

On March 1113 200913 Pond13 5 upper was13 harvested13 and13 split into13 two13 separate13 groups

Two hundred of the smaller fish (average size = 122 mm TL) were PIT tagged and placed

into13 Pond13 7 upper and13 200 of the13 larger13 fish (average = 160 mm TL) were PIT tagged and

placed int Pond13 8 upper Density13 in Pond13 7 was13 4500 fish and13 in Pond13 8 there13 were13 6500

fish These ponds were then harvested after 1 year and growth rates were compared to

give information on the effects of current sorting practices Hobotempreg temperature

loggers were installed in13 Ponds 7 and13 8 during13 the13 grow-shy‐out period with13 water13

temperature recorded every 2 hours13 (Figure13 6)

Effect of Ich on razorback sucker growth rates

Bubbling Ponds spring was treated with Rotenone (CFT Legumine 5) at a

concentration of 2 ppm13 to remove all mosquitofish from13 the spring The treatment

consisted of two treatments 6 hours in duration on two consecutive days (April 12 -shy‐ 13)

using13 drip13 stations13 and13 backpack sprayers13 followed13 by13 an13 additional 6 hours13 of

detoxification using sodium13 permanganate Although 12 mosquitofish were captured in the

spring pond the week following the treatments subsequent minnow trapping (20 traps

checked13 daily13 for 3 weeks) did not capture any additional fish until August 11 2010 when

41

13

juvenile mosquitofish were again detected in the spring pond Minnow traps have

subsequently been set daily with several hundred individuals removed To evaluate if Ich

was also again present in the spring we captured 15 mosquitofish from13 the spring pond on

three separate days and placed them13 in an aquaria at 25 degC with 5 longfin dace known to be

free of Ich These fish were monitored for 2 weeks with no signs of Ich developing This

indicates that even though mosquitofish have returned to the spring pond the parasite is no

longer present13 although how13 long13 this condition13 will13 persist13 is unknown13

On May 1113 201013 200 juvenile razorback13 suckers were harvested out13 of Pond 5

upper (2009 year Class from13 Dexter National Fish Hatchery) and were PIT tagged and

placed into Pond 8 to evaluate if growth rates at bubbling ponds hatchery have improved

following the renovation of the spring and the removal of the Ich parasite Unfortunately13

on Sept13 8 2010 Ich was13 again13 detected13 in Pond 8 and the pond was immediately seined

and 74 tagged fish were measured to obtain growth information for the 4-shy‐month period

during13 which13 the13 pond13 was13 Ich-shy‐free13

Figure13 6 Temperatures (degC) in rearingponds 7 and 8 at Bubbling Ponds Hatchery13 from March 2009 ndash March 201013 pond 7(top13 graph)13 and13 pond 8 (Lower13 graph)13 Temperatures recorded with a Hobotempregremote data logger every 3 hours

42

13

Results

Growth in Lined Ponds

Razorback suckers13 that had been13 in13 Pond 8 upper for the13 entire13 year13 grew an13

average of 0263 mmday (789 mmmonth) and razorback suckers that had been in the

pond for 7 months (Oct -shy‐ May) grew13 on13 average of 028 mmday (843 mmmonth) (Figure13

7) These growth13 rates13 did not significantly13 differ Fish density13 in Pond 3 during13 the13

majority of the growth period was13 00032 ndash 00036 fishgallon13 Additionally no13 significant

differences in growth rate were observed between fish smaller than 210 mm TL and fish

larger than 210 mm TL when all recaptured fish were combined

We also measured the growth rate of very large fish in a lined pond On Jan13 2513 201013

156 adult fish with PIT tags were recovered from13 Pond 3 upper13 These fish were13 in the13

pond for 257 days and experienced an average13 growth13 rate13 of 024mmday or 73

mmmonth (Figure13 7)13 This growth13 rate13 is slightly13 lower13 than13 the13 average13 growth13 rate13

observed13 at Bubbling13 Ponds Hatchery in other studies (0275 mmday 825 mmmonth)

but may not be biologically meaningful We would expect larger13 fish to13 have13 reduced

growth rates according to a typical Von Bertalanfy growth model (Bertalanffy 1957) but it

appears that13 over the size range we evaluated (300 -shy‐ 450 mm TL) growth rates have not

slowed significantly compared to that of smaller13 fish grown at Bubbling Ponds13 Hatchery

Growth13 of razorback suckers13 is known13 to13 slow as13 fish reach13 larger13 sizes but it appears13 this13

reduced growth rate may not really start to be biologically meaningful at Bubbling Ponds

Hatchery13 until razorback suckers13 exceed 450 mm TL

Growth in unlined ponds

Growth13 rates13 for the13 fish recaptured13 during13 the Pond 1 lower13 thinning13 (120 days13 in

the pond) was 024 plusmn 003 mmday (729 plusmn 090 mmmonth) (Figure13 8)13 Fish13 that were13 in

the pond for nearly the entire year grew13 an13 average13 of 024 plusmn 001 mmday (726 plusmn 027

mmmonth) These growth rates are surprisingly the lowest measured growth rates for

any part of our study and differ significantly from13 every other measured growth rate

except very large13 fish (Figure13 9)13 Separating13 out13 large fish that13 were in13 the pond for the

entire year makes no difference fish that were added to the pond at TL lt300 mm grew

43

13

Gro

wth

Rat

e (m

md

ay)

020

026

032

0244 plusmn 001 mmday (733 plusmn 028 mmmonth) and and those with TL gt= 300 mm at the

start of the experiment grew 022 plusmn 003 mmday (651 plusmn 101 mmmonth)

Razorback Growth Rates in Lined Ponds

Figure 7 Growth ofrazorback suckers in(mmday plusmn standard error)in Pond 8 upper in 2008-shy‐2009 An ANOVA did notdetect any significantdifferences

7 Months Full Year 300+ mm fish

Effects of sorting on growth

One hundred and seventy five tagged razorback suckers were recovered from13 Pond

8 upper13 on March13 24 2010 (378 days13 of growth)13 These were13 the13 larger sorted13 fish (gt140

mm TL) that came out of Pond13 5 on March13 11 2009 One13 hundred and13 twenty13 two13 tagged13

razorback suckers were also recovered from13 Pond13 7 upper on March13 31 2010 (385 days13 of

growth)13 These were13 the13 smaller sorted13 fish (lt140 mm TL) that came out of Pond13 5 on

March 1113 200913 No significant differences in growth rate (mmday) were observed among

larger fish in Pond 8 and smaller fish in Pond 7 (pgt005 ANOVA) (Figure 10)13 indicating

that13 sorting may have helped to offset the original slower growth trajectory of the smaller

fish Temperatures of Ponds 7 and 8 upper remained similar throughout the year13 (Figure

5)

44

13

13

13

Gro

wth

Rat

e (m

md

ay)

Gro

wth

Rat

e (m

md

ay)

020

026

032

020

026

032

Razorback Growth in an Unlined Pond

Figure 8 Growth of razorbacksuckers (mmday plusmn standard error) in Pond 1 lower (an unlined pond)in 2010-shy‐2011 An ANOVA did notdetect any significant differences

6 Months 12 Months lt 300 mm Fish 300+ mm Fish Growth Growth

Lined vs Earthen Ponds 1 year of growth

Figure 9 Growth of razorbacksuckers (mmday plusmn standard error) in lined and unlined ponds A t-shy‐test13 did not detect a significantdifference

Lined Pond Unlined Pond 1 Yr Growth 1 Yr Growth

45

13

Effect of Sorting G

row

th R

ate

(mm

day

) G

row

th R

ate

(mm

day

)

032

020

026

032

020

026

Smaller Fish Larger Fish

Effect of Ich

Figure 10 Average growthof razorback suckers(mmday plusmn standard error)that were size-shy‐sorted intosmall fish (pond 7) and largefish (pond 8) populations At-shy‐test did not detect asignificant difference

Figure 11 Average growth ofrazorback suckers (mmday plusmnstandard error) after Ich wasremovd from the hatcheryrsquos springand after Ich was again detected inthe pond The growth rate withoutIch is significantly higher than boththe rate after Ich and the ourstudyrsquos average annual growth ratein lined ponds (ANOVA p =00003)

Growth without Ich Growth With Ich Average Annual 4 months 4 months Growth Rate

46

13

Effect of Ich on razorback sucker growth rates

Seventy-shy‐four13 tagged13 razorback suckers13 were13 recovered from13 Pond 8 on September

15 2010 These fish had13 been13 in the pond for 4 months and experienced a growth rate of

032 mmday or 97 mmmonth (Figure13 11)13 This growth13 rate13 is significantly higher (p =

005 two sample t-shy‐test) than the mean growth rate for the same group13 of tagged fish after

Ich detection (022 mmday or 65 mmmonth) and significantly higher than any other

individual growth13 rates13 observed13 to13 date13 at Bubbling13 Ponds Hatchery13 (Figure13 11)13 If this13

growth13 rate13 were13 extended throughout13 the entire13 year13 fish on average from13 Ich-shy‐free13 ponds13

would be 16 mm longer than fish from13 ponds infested with Ich Studies conducted at

Bubbling Ponds hatchery in 2008 (Ward 2008) did not reveal any effects of the treatment

chemicals on razorback sucker growth rates so it13 is likely that13 the parasite outbreaks

themselves are causing reducing growth rates rather than the chemicals used to treat the

parasites13

Conclusions

Our results suggest that under typical hatchery operations (maximizing number of

fish produced)13 the growth13 rate13 of razorback13 suckers13 is relatively13 consistent at Bubbling13

Ponds hatchery13 at 02-shy‐03 mmday (6-shy‐9 mmmonth)13 but is lower than growth13 rates13 at

other13 facilities (02 ndash 18 mmday Ward et al 2007)13 This growth13 rate13 has13 been13 constant in

both lined and unlined ponds and at all fish densities we were able to measure To achieve13

growth13 rates13 substantially higher than this will likely require13 significant changes in rearing

practices that may not be practical in order to reach numerical production13 goals

Temperature is a key variable in fish growth but seasonal growth patterns

described13 above13 (Figure13 5) demonstrate that water temperatures are high enough in

winter to maintain razorback growth Differences in water temperature by season

currently13 do not fluctuate more than 10degC at Bubbling Ponds because of the continuous

supply of water flowing through each pond (approx 225 gallonsmin) These high water

flows appear to keep pond temperatures within the thermal preference13 for razorback

suckers13 (1213 -shy‐ 28 degC Bulkley and Pimentel 1983) throughout the entire year with

temperatures rarely dropping13 below 16deg13 C (Figures 513 6)13

47

13

Fish density is another key variable in fish growth and though the number of fish in

a pond during our study ranged from13 3000 to 700013 fish we13 did not find any13 correlation13

between13 density and growth rate13 This might yield two conclusions First13 razorback

growth13 may be changed equally13 by13 densities13 at the13 hatchery13 (ie13 a density13 of 3000 fish in a

pond is as stressful13 for razorbacks as a density13 of 7000 fish) An alternative is that other

factors13 such as disease outbreaks have13 stronger13 control over fish growth13 than13 density13

Fish density13 would13 have13 to13 be13 experimentally manipulated to test13 this13 and hatchery

operations (producing the maximum13 number of fish) prevented our manipulating density13

in ponds for this13 work The trouble with manipulating density demonstrates the difficulties

associated with changing13 hatchery13 practices experimenting with density would have

prevented BPH from13 meeting13 production13 goals Given that the stocking of smaller

razorbacks has met with very little success perhaps BPH goals could be changed from13

producing 12000 fish at 300+ mm per year to a smaller number of very large fish each

year Growing13 fewer13 larger13 fish could potentially be accomplished in the same time frame

as more smaller fish but a better understanding of how density alters growth rate would

be required to be confident13 of this

The very slow growth13 in the13 earthen13 unlined13 Pond 1 lower13 was very surprising We13

had13 anticipated13 that the13 diversified diet13 cover and13 other13 habitat features13 provided by13

unlined ponds would yield dramatically increased growth rates However these traits were

not enough to offset high fish densities and in fact the unlined pond in our study13 suffered

mortality to bring densities down to that observed normally in lined ponds

Our data13 suggest13 that razorbacks13 sucker13 growth13 rates13 are13 higher in lined13 ponds13

However we13 think the reasons13 for the13 very slow growth we observed13 in the13 unlined13 pond13

in our study13 is instead13 linked13 to13 the13 usage13 of Pond 1 lower13 during13 the13 study13 rather13 than13

intrinsic13 slow growth13 in earthen13 ponds First the pond was at extremely high density for at

least part of the study The volume of Pond 1 lower has not been estimated but hatchery

managers suggest 1500-shy‐2000 fish is an appropriate number of individuals so this pond

was at a very high density for much of the experiment Second dissolved oxygen is often

very low in the13 large13 earthen13 ponds during the heat of summer much lower than that of

lined ponds This will both limit the number of fish that can survive in the pond and almost

certainly13 increases stress13 of these13 fish potentially13 reducing growth13 The DO crashes also13

48

13

limit the amount of feed hatchery managers can give fish in these ponds sometimes for

days or weeks at a time which further reduces growth during warm13 weather

Our data13 suggests that13 growth rates at the Bubbling13 Ponds Fish Hatchery are likely

as high as possible given13 the pond densities required to meet production goals and the Ich-shy‐

infested water that feeds the facility Sorting practices are successful in helping as many

fish as possible reach stocking length as fast as possible Unlined ponds may be able to

grow13 large13 fish at low13 densities13 but whatever factors allow13 for that13 growth are not13 able to

overcome high fish density The removal of invasive13 fis that act as13 a host for the13 parasite13

Ich fish from13 the Bubbling13 Ponds spring13 allowed the highest13 growth rate at 032 mmday13

(96 mmmonth) but that growth rate decreased again as Ich re-shy‐infested13 the13 hatchery13

Consistently13 achieving13 growth13 rates13 as high or substantially13 higher than13 this13 will likely13

require13 significant changes in rearing practices that may not be practical in order to13 reach13

numerical production13 goals

Two major changes that might result in higher growth rates are substantially

reducing fish density and modifying the way spring water is delivered to the facility (via

either repeated chemical treatments or enclosed concrete water diversions) to eliminate

Ich from13 the hatchery source water Other potential changes not address by our work

include13 flow-shy‐training razorbacks much previous literature including MSCP-shy‐funded13 work

on razorback suckers13 suggests13 that fish growing13 in flowing water will grow13 faster than fish

in still water (Jorgensen and Jobling 1994) Furthermore there are a wide variety of

potential benefits associated with growing13 fish13 in flowing13 water in addition13 to increased

growth13 rates13 (Davidson13 199713 Castro13 et al13 2011) Another option13 for increasing13 growth13

rates13 include13 changing to13 intensive13 culture13 in large circular13 tanks

Finally given that the stocking of smaller razorbacks has met with very little

success13 perhaps13 BPH13 goals13 could13 be13 changed from13 producing 12000 fish at 300+ mm per

year to a smaller number of very large fish each year Growing fewer larger fish could

potentially be accomplished in the same time frame as more smaller fish but a better

understanding13 of how density13 alters growth13 rate13 would13 be13 required to13 be13 confident of this

49

13

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower13 Colorado13 River Multi-shy‐Species13

Conservation Program13 (LCRMSCP) under Work Task C10 We13 thank Ty Wolters13 Tom13

Burke13 and Eric13 Volkman for their support of this research and Frank Agygos and Dave

Billingsly13 of the Bubbling13 Ponds Fish Hatchery13 for their willingness to participate in13 this

research13 and13 for their technical assistance We also thank the LCRMSCP fish group from13

Boulder City13 NV for their assistance with harvesting13 ponds and tagging13 fish13

50

13

Literature13 CitedAnders P J 1998 Conservation aquaculture and endangered species can objective science13

prevail13 over risk13 anxiety Fisheries 23(11) 28-shy‐31

Anderson R O and R M Nuemann 1996 Length weight and associated structural indicesPages 447 ndash 482 in B R Murphy13 and D13 W Willis13 editors13 Fisheries techniques13 2ndedtion American Fisheries13 Society13 Bethesda13 Maryland

Bain M B J T Finn and H E Brooks 1988 Streamflow regulation and fish communitystructure13 Ecology13 69382-shy‐392

Bays J H Zarbock R Whitman and T Murphy 2005 Conceptual design and managementof native13 fish refugia on the13 lower13 Colorado13 River In13 CL Spring13 and13 S Leoneditors Proceedings of two symposia Restoring native fish to the lower ColoradoRiver13 interactions13 of native and non-shy‐native13 fishes 13ndash1413 July13 1999 Las13 Vegas13 Nevada13 Restoring13 natural function within a modified riverine environment thelower Colorado River13 8ndash913 July13 1998 U S Fish and13 Wildlife13 Service Southwestern13 Region Albuquerque New Mexico Pages 167-shy‐177

Bertalanffy L Von 1957 Quantitative laws in metabolism13 and growth13 Q Rev Biology 32217 ndash 231

Bingham T B Scheer and C McAda 2003 Propagation facilities in Grand Valley (24 RoadHatchery Horsethief13 Ponds and13 grow-shy‐out ponds) for captive13 rearing13 ofendangered13 fishes for the13 upper13 Colorado13 River basin13 Colorado River RecoveryProgram FY2003 annual project report13 US Fish and13 Wildlife13 Service GrandJunction13 4pp

Birchell G J and K Christopherson 2004 Survival growth and recruitment of larval andjuvenile razorback13 sucker (Xyrauchen texanus) introduced13 into13 floodplain13 depressions13 of the13 Green River Utah13 Final report13 Upper13 Colorado13 RiverEndangered Fish Recovery Program13 Project No C-shy‐6RZ Publication Number 04-shy‐1513 Utah13 Division of Wildlife13 Resources Salt Lake13 City13 Utah13 67 pages

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Brett J R 1979 Environmental Factors and growth pages 599-shy‐67513 InW S Hoar13 D13 J13 Randall and J R Brett (eds) Fish Physiology Volume 8 Bioenergetics and GrowthAcademic Press New York

Brooks J E 1986 Annual reintroduction and monitoring report for razorback suckerXyrauchen texanus in the Gila River Basin Arizona 1985 US Fish and WildlifeService13 Offices of Endangered13 Species and Fishery13 Resources Albuquerque 23 pp

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Brunson13 R E and K D13 Christopherson13 200513 Larval13 razorback13 sucker and bonytailsurvival and13 growth13 in the13 presence13 of nonnative13 fish in the13 Baeser13 floodplainwetland of the middle Green River Final report prepared for Upper13 Colorado RiverBasin Endangered Fish Recovery Program Project No C-shy‐6-shy‐rz-shy‐bt Publication13 No 05-shy‐26 Utah13 Division of Wildlife13 Resources13 Vernal13 32 pp

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Burke13 T13 199513 Rearing13 wild razorback13 sucker larvae in13 lake-shy‐side13 backwaters13 LakeMohave ArizonaNevada Proceedings of the Desert Fishes Council 2635

Busacker G P I R Adelman and E M Goolish13 199013 Growth13 Pages 363 ndash 387 in C BSchreck and p B Moyle editors Methods for fish biology American FisheriesSociety Bethesda Maryland

Castro V B Grisdale-shy‐Helland S J Helland T Kristensen S M Jorgensen J Helgrud13 GClaireaux A P Farrell A Krasnov and H Takle 2011 Aerobic training stimulatesgrowth and promotes disease resistance in Atlantic salmon (Salmo salar)Comparative Biochemistry and Physiology -shy‐ Part A Molecular amp IntegrativePhysiology13 160(2) 278-shy‐290

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Koebele13 B P13 198513 Growth and the size hierarchy effect an experimental assessment ofthree proposed mechanisms activity differences disproportional food acquisition13 pysiological stress Environmental Biology of Fishes 12 181-shy‐188

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Marsh13 P13 C13 1987a13 Digestive tract13 contents13 of adult razorback suckers13 in Lake13 MohaveArizona-shy‐Nevada Transactions of the American Fisheries Society 116117-shy‐119

Marsh P C 1987b Native fishes at Buenos Aires National Wildlife Refuge and ArizonaState University Research Park Arizona opportunities for management researchand public13 education13 on13 endangered species13 Proceedings of the Desert13 FishesCouncil 1967-shy‐78

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Ulibarri M E 2003 Annual report fiscal year 2001 Dexter National Fish Hatchery13 andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 26 pages

Ulibarri M E 2003 Annual report fiscal year 2002 Dexter National Fish Hatchery andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 59 pages

USBR 2006 Lower13 Colorado13 River Multi-shy‐Species Conservation Program final fishaugmentation plan Boulder City 19 pp

USFWS 2002 Razorback sucker (Xyraouchen texanus) recovery goals Amendment andsupplement to the Razorback Sucker Recovery Plan13 US Fish and Wildlife Service13 Region 6 Denver13 Colorado

USFWS 1999 Annual report 1999 Ouray National Fish Hatchery Vernal 25pp

USFWS 2004 Management plan for the big-shy‐river13 fishes of the13 lower13 Colorado13 river basinamendment and supplement to the bonytail humpback chub Coloradopikeminnow and razorback sucker recovery plans

USFWS13 2005 Station13 profile13 of the13 Dexter13 National Fish Hatchery13 and Technology CenterUS Fish and Wildlife13 Service Dexter

Valdez R A P G Mangan R Smith and B Nilson 1982 Upper Colorado River fisheriesinvestigations13 inW H Miller J J Valentine D L Archer H M Tyus R A Valdezand L13 Kaeding13 editors13 Colorado River Fishery13 Project13 Part 2 Field13 investigations13 US Bureau of Reclamation Salt Lake City Utah

WBNFH 2004 Culture methods of the endangered razorback sucker Xyrauchen texanusUS Fish and Wildlife13 Service Willow Beach National Fish Hatchery13 8 pp

Ward D 2008 Effects of disease treatments on growth of razorback sucker ReportSubmitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 Inpartial fulfillment of work task C10 agreement number 06FG30039

Ward13 D13 M Childs and W Persons 2007 Factors13 affecting13 growth13 of razorback sucker13 (Xyrauchen texanus) in captivity Literature review and knowledge assessmentReport Submitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 In partial fulfillment of work task C10 agreement number 06FG30039

57

Appendices

Appendix 1 Survey Questions Survey of Razorback Sucker Culture in the

Southwestern United States

The enclosed survey is being distributed by the Arizona Game and Fish Department to razorback sucker culture facilities throughout

the Southwestern United States The purpose of this survey is to consolidate information regarding culture of this species so that

appropriate facility improvements can be considered for Bubbling Ponds Hatchery in Arizona Specifically we wish to increase

growth rate and production efficiency at the hatchery Information gathered in this survey will be summarized in a final report to US

Bureau of Reclamation in Boulder City NV and disseminated to all facilities that participate in the survey A workshop to discuss

the findings of this study as well as to share general information concerning razorback sucker culture will be organized by the

Arizona Game and Fish Department at the conclusion of this study and all participants will be invited

Thank you for taking the time to fill out this survey Please contact Mike Childs if you have questions or would like to discuss the

survey

Mike Childs

mchildssedonanet

(928) 639-1346

(928) 634-1279

Facility_____________________________________ Date___________________

Contact Phone _____________________________

ContactPerson_______________________________

Contact Email _______________________________

1 Water quality ranges at this culture facility

Season

Spring (Mar-May) Summer (Jun-Aug) Fall (Sept-Nov) Winter (Dec-Feb)

Temperature (C)

PH

DO (mgL)

PO4 (mgL)

TDS (mgL)

Hardness (mgL)

CaCO3

Pathogens

37

13

Introduction

Preservation13 of razorback sucker13 (Xyrauchen texanus) currently13 depends on captive13

rearing and stocking programs until permanent solutions to factors that prevent wild13

recruitment are found Low survival of stocked razorback suckers (Brooks 1986 Marsh

and Brooks 198913 Marsh and Pacey13 2005) has caused target13 sizes for stocked fish to

steadily increase in efforts to reduce predation mortality (Marsh et al 2005 Schooley and

Marsh 2007) Rearing fish to larger sizes at hatcheries comes with increased costs and

creates the need to evaluate husbandry and rearing practices that may affect fish growth

Formalin copper sulfate potassium13 permanganate and salt are all chemicals

commonly used at razorback sucker rearing facilities to treat outbreaks of the protozoan

parasite13 Ichthyophthirius multifiliis ldquoIchrdquo is one of the most pathenogenic diseases of

cultured13 freshwater13 fishes (Matthews13 2005) and causes large13 losses in captive13 populations13

of endangered razorback sucker Each of these chemicals used to treat Ich only kill the free-shy‐

swimming life stage of the parasite13 requiring13 repeated doses over several13 days depending13

on water temperature These chemicals treatments are needed to prevent loss as a result

of disease outbreaks but the cumulative effects repeated disease treatments have on

growth13 are13 unknown

Copper13 sulfate13 has13 been shown to13 significantly13 reduce13 growth13 of channel catfish13 in

production13 ponds (Rabago-shy‐Castro13 2006) but it is unknown whether13 razorback suckers13

experience similar reduced growth following copper treatment Quantifying the impacts of

disease treatments on growth will help to interpret the wide differences in growth rates

observed13 at various13 razorback sucker13 production13 facilities13 throughout the13 southwest

(Ward et al 2007) If one chemical is found to have less detrimental impacts on growth

than another then it may be preferred for use as a disease treatment We evaluated growth

rates13 of razorback suckers13 under13 replicated13 and13 controlled13 conditions13 to13 assess13 effects13 of

repeated formalin copper sulfate and potassium permanganate and salt treatments on

growth13

Methods

We captured 190 juvenile razorback suckers from13 ponds at Bubbling Ponds Fish

Hatchery AZ using hoop nets or cast nets All fish were of the same age class and

30

13

averaged 179 mm total length (TL) (range13 = 127 ndash 262 mm TL)13 These fish were13 offspring13

of captive13 razorback sucker13 broodstock held13 at Dexter13 National13 Fish Hatchery13 NM13 (2007

year class) All fish were tagged with passive integrated transponder (PIT) tags and

quarantined for one month prior to the experiment to allow fish to recover from13 tagging

and become accustomed to being held in circular tanks

At the beginning of the study all fish were weighed measured and scanned for

individual tag numbers with 19 randomly selected fish placed into each13 of 10 8-shy‐foot

diameter circular tanks (Figure 2)13 Each13 tank contained13 two13 airstones13 and13 an13 individual

biofilter with a recirculating water pump (31 litersminute) that had been operating for

at least 1 month prior to the experiment to allow bacterial colonies to become

established Two tanks were designated as a control and did not receive any chemical

treatments while the other eight tanks received formalin copper sulfate potassium13

permanganate or salt treatments at two week intervals (two tanks per chemical

treatment) Formalin copper sulfate and potassium13 permanganate were treated at 1 part

per million (ppm) and salt was applied at 30 parts per thousand (ppt) These treatment

rates are commonly used to treat13 razorback13 suckers for ich at Bubbling13 Ponds Fish13

hatchery (Frank Agygos personal communication)

Figure 213 Photo ofexperimental tankswith individualbiofilters and aeration

31

13

Each treatment consisted of a series of doses applied on Wednesday Thursday and

Friday with a 90water change between each dose Biofilters were removed from13 all

tanks and held in a separate holding facility during treatments and then replaced on the

Monday following treatments after a 90water change This schedule allowed fish to be

exposed to chemical treatments for 5 consecutive days without water quality deteriorating

This 5-shy‐day chemical treatment was repeated every two weeks from13 July to October (97

days)13 for a total of 5 5-shy‐day treatments Water temperature in the treatment tanks ranged

from13 13degC (55degF) to 32degC (91degF)

Fish were fed a fixed ration of commercial razorback diet (Silvercup 4mm13 pellet)

once daily13 (2 percent body13 weight per day13 as calculated13 by13 average initial fish weight)13

At the end of the experiment all fish were again weighed measured and scanned for

individual tag numbers Growth of fish in each treatment group was compared using

analysis of variance (ANOVA) Any mortalities13 that occurred during the13 study13 were13

replaced with previously quarantined fish of equivalent size to maintain equal densities in

each13 tank13 but growth13 data was13 only13 recorded for fish which13 survived13 the13 entire13

experiment

Results

Fish at the13 start of the experiment averaged 179 mm TL (Range13 = 127 ndash 262 mm)

with no significant differences in fish length among treatment groups (F(4189) = 00183 p

gt 0999 ANOVA) On average fish grew 235 mm TL (024 mmday) during the 3 month

study13 Fish in tanks13 treated with formalin had the highest growth averaging 29 mm TL (03

mmday) while fish in tanks treated with copper had the lowest growth averaging 20 mm

TL (021 mmday) Fish in the control tanks averaged 213 mm TL in growth (022

mmday) (Figure13 3)13 Formalin-shy‐treated fish grew13 significantly faster than13 any other

treatment group but no13 significant differences in growth13 in length13 or weight were13

observed among fish treated with any of the chemicals compared to untreated (control)

fish (pgt005 ANOVA)

32

13

Figure 313 Average growthof razorback suckersexposed to a series of 5 5-shy‐day chemical treatmentsover a 97-shy‐day13 periodError bars representstandard error

Discussion13

Growth13 rates13 observed13 in our study13 (021 ndash 03 mmday) are low compared to those

reported13 in other13 studies13 of razorback sucker13 growth13 (0213 ndash 18 mmday) (Ward et al

2007) Using recirculating water systems for our study required filters to be removed and

replaced during treatments Stress to fish caused by removing and replacing filters within

the tanks as well as repeated water changes may have led to overall higher stress and

reduced growth rates compared to those reported for unconfined fish Growth in fish is

highly variable and is affected by many different physiological and environmental factors

including fish size density temperature amount of space and food (Brett 1979) We

strived to control each of these factors but other factors may have also influenced growth

in our experimental tanks During mid-shy‐summer water temperatures in the treatment

tanks reached 32degC (91degF) At these warm13 temperatures fish are very susceptible to

bacterial13 infections13 The slightly higher growth exhibited by fish in the formalin and

potassium13 permanganate treatments may have been the result of these two chemicals

33

13

being effective at controlling bacterial infections The differences in growth we measured

among treatment groups were not statistically significant and do not appear13 biologically13

meaningful during the relatively short duration of this study (97 days) although the

cumulative effects of slightly reduced growth could be biologically meaningful over longer

time frames

Reductions in growth13 as a result13 o repeated chemical treatments are not likely the

cause of differences in growth rates among facilities that raise razorback suckers

Repeated chemical treatments may have other impacts to overall fitness or long-shy‐term13

survival but these13 effects13 were13 not evident in our study It is more likely that the parasite

outbreaks themselves are the cause of different growth rates among razorback rearing

facilities rather than the chemical treatments used to treat the parasites We recommend

that hatchery managers continue to use the chemicals that are most effective at controlling

ldquoIchrdquo13 at their individual13 facilities

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower Colorado Rive Multi-shy‐species13

Conservation Plan under Work Task C10 We thank Ty Wolters and Tom13 Burke for their

support of this research and Frank Agygos and Dave Billingsly of the Bubbling Ponds Fish

Hatchery13 for their13 technical assistance13 and13 help with13 collecting13 fish

34

13

III13 Razorback Growth Rates at Bubbling Ponds ndash 2009-shy‐2011

Section13 SummaryExperimental studies at Bubbling Ponds Fish Hatchery AZ have strived to understand

factors that affect razorback sucker growth in captivity and identify ways to improve growthrates and maximize size at release Rather than performing experimental studies that wouldrequire major13 rearrangement (and likely reduced production)13 of hatchery operations our13 studies13 used normal variation in production techniques13 and practices13 to isolate factors13 thatmay modify growth rates

Our initial work identified razorback13 growth rates in13 lined ponds at standard fishdensity as 026 to13 028mmday (789 to 843 mmmonth) No significant differences in growthrate were observed among fish that had been in the pond only during the winter13 periodcompared to fish that had been in the pond the entire year indicating that water temperatures13 at Bubbling Ponds are high enough to allow fish to incorporate feed effectively year-shy‐roundHowever these growth rates are lower than most values reported from the literature fromnatural or semi-shy‐natural pond environments No significant differences in13 growth rate wereobserved13 between large and13 small fish13 within the 150 ndash 29 mm TL13 size range Additional worksuggests13 that razorback suckers13 tagged at over 300 mm TL had reduced growth rates (024mmday 73 mmmonth) as would be expected according to a typical Von13 Bertalanfy growthcurve although growth rates13 were only slightly less13 than the average growth rate for thehatchery (027513 mmday 82513 mmmonth)

Sorting13 to13 separate small fish from large fish after the first year of growth is practicedesigned13 to allow smaller fish to ldquocatch uprdquo to larger fish We found that13 this technique doesappear to13 improve growth rates of smaller fish Growth rates of sorted small razorback suckers(029 mmday 87mmmonth)13 were equal to that13 of larger13 fish (028 mmday 8413 mmmonth)indicating that sorting may have helped to offset their original slower growth trajectory

Bubbling Ponds Fish Hatchery grows razorbacks in 6 long deep ponds lined with heavyplastic 2 long deep13 earthen13 (unlined) ponds and three wide shallow earthen ponds The wideshallow ponds13 have historically produced very large fish at low density but have been found tomaintain much lower fish numbers than deeper ponds We found13 that growth13 rates ofrazorbacks kept at high density (4-shy‐700013 fish)13 in a wide shallow pond grew extremely slowly(024 mmday 726 mmmonth) This growth rate is among the slowest of any fish over theyears of our study and demonstrates that13 though the large ponds may produce large fish at lowdensity13 they are unable to overcome high13 fish13 densities

Finally one of the major factors influencing13 fish13 growth13 in hatcheries is disease onemajor summer-shy‐time disease at13 Bubbling Ponds is the ectoparasite Ich (Ichthiopthirusmultifiliis) To investigate the impact Ich has on razorback growth we eradicated fish from thespring and water conveyance ditch that supplies13 water to the hatchery using Rotenone This13 restoration effort was fairly short-shy‐lived (Ich returned to the hatchery within four months) but

35

13

growth13 rates of fish13 reared for four months without Ich present (031 mmday 92 mmmonth)were significantly higher than the following 8 months of growth for those same fish (022mmday 65 mmmonth) This disease-shy‐free growth rate is in fact faster than any13 otherprevious growth rates observed at the hatchery in our study

We conclude that growth rates at the Bubbling Ponds Fish Hatchery are likely as highas possible given the pond densities required to13 meet production goals and the Ich-shy‐infestedwater13 that feeds the facility Sorting practices are successful in helping as many fish as possiblereach stocking length as fast as possible Unlined ponds may be able to grow large fish at lowdensities but whatever factors allow for that growth13 are not able13 to overcome13 high fish densityThus the large lower ponds at Bubbling Ponds may be better utilized via renovation to13 deepenand line them

Disease is the most important factor limiting growth as may be expected to be the caseat many13 hatcheries While the spring renovation was not13 a complete success13 the dramaticreduction of fish populations in that habitat was enough to dramatically13 reduce13 the13 occurrenceof Ich at the hatchery13 Such open spring13 systems feeding a hatchery are a misfortune that canbe expected to transmit disease so we suggest that renovating the spring again to combat13 IchImproved techniques to divert water from13 the springs and more throuough treatment ofstream-shy‐side vegetation may improve the success of chemical treatment Successful renovationwould likely both improve growth rates and reduce chemical costs associated with treating Ichoutbreaks Even13 if complete renovation13 is impossible or impractical an13 effort to reduceinvasive fish density in the springs13 which act a vector for the parasite(and thereby reduce thelikelihood of13 Ich being transmitted into ponds) may still13 show dramatic improvements

36

13

Introduction

Conservation efforts13 for razorback sucker13 (Xyrauchen texanus)13 currently13 depend on

captive rearing and stocking programs Low survival of stocked razorback suckers (Brooks

1986 Marsh13 and13 Brooks13 1989 Marsh13 and13 Pacey13 2005) has13 caused13 target sizes for stocked13

fish to steadily increase in efforts to reduce predation mortality13 (Marsh13 et al13 2005

Schooley and Marsh 2007) Rearing fish to larger sizes at hatcheries comes with increased

costs and creates the need to evaluate husbandry and rearing practices that may affect fish

growth13 We evaluated growth13 rates13 of individual razorback suckers13 in ponds13 at Bubbling

Ponds Fish Hatchery13 using Passive Integrated13 Transponder (PIT) tags13 to13 obtain13 precise

growth information for individual fish so that valid comparisons of growth rates as related

to rearing practices can be made

Due to the critical nature of the razorback sucker stocking program we did not

design experimental studies that would require major rearrangement and potentially

reduce production of hatchery operations Instead our studies used normal variation in

production techniques and practices to isolate factors that may modify growth rates

Though this methodology dramatically limits replication and may limit our ability to

directly13 attribute13 differences in growth13 rates13 to13 the13 variables13 we13 investigate13 we13 were13 able13

to accomplish research goals without altering hatchery operations or impacting

production

From13 2009 through 2011 we conducted a series of observational13 growth13 studies to

determine growth rates of individual razorbacks at Bubbling Ponds The first set of

experiments included13 identifying13 growth13 rates13 in lined13 and13 unlined13 ponds determining

growth13 rates13 of fish at different13 sizes13 in13 relation13 to sorting13 practices and monitoring

razorback growth rates after removing the source of the ectoparasite13 Ich (Ichthiopthirus

multifiliis) from13 the hatchery water source13

Razorback growth rate in lined ponds

Our first growth study documented individual growth rates at normal density in 11

million gallon lined ponds13 over two13 years13 This is the standard13 grow-shy‐out process for

razorbacks13 at Bubbling Ponds We monitored growth of fish for a variety13 of sizes and13 the13

37

13

amount of time in a pond during the growing season These13 data give a snapshot of growth13

rates13 at the13 facility13 and13 provide13 the basis for comparisons throughout our study

Growth rate13 in an unlined pond

In addition13 to 6 ponds lined with heavy plastic13 sheeting13 Bubbling Ponds Fish13

Hatchery maintains two narrow and deep (same dimensions as lined ponds13 Figure13 4)13 and13

three large13 shallow unlined ponds These earthen13 ponds typically have vegetation and

associated aquatic invertebrates that may better simulate natural environments by

providing cover and improved food diversity or quality Therefore these unlined ponds

may be expected to produce higher growth rates and potentially improved survival that is

more similar to growth rates observed in more natural grow-shy‐out facilities13 Historically13 the13

large13 shallow13 ponds have produced very large fish when13 utilized at low13 fish density13 The

narrow13 deep earthen13 ponds are13 used to grow13 fry13 at high density in their first13 year of life

The major downside to unlined ponds is the difficulty in harvesting fish where a lined

pond might take 8-shy‐1013 people13 a half13 day13 to13 harvest13 lined13 ponds13 require13 intensive13 weeding13

to allow seines to be pulled and therefore require many more personnel-shy‐hours13 In addition13

to harvest challenges the shallow earthen ponds tend to suffer from13 dissolved oxygen

crashes during the summer Unlined ponds also may maintain higher13 populations13 of non-shy‐

target species such as bluegill sunfish mosquito fish and bullfrog tadpoles We measured

growth rates of suckers in a large shallow earthen pond for comparison to growth in lined

ponds13

Figure13 4 Lined13 and13 earthen ponds13 of similar dimensions (approx 1000000 gallons first

and second panels) and a large13 shallow13 earthen13 pond (third panel)

38

13

Effect of sorting on growth

Razorback13 suckers13 are13 currently13 sorted13 after their first13 year of growth13 They are13

typically removed from13 one of the13 upper earthen13 ponds and13 split into13 two13 lined13 ponds for

subsequent grow-shy‐out13 The larger13 fish (gt approximately 140 mm) are placed into one pond

and the smaller individuals in another It is possible that the larger fish were more

aggressive or adept13 at taking food so this sorting process is intended to allow smaller fish

to improve their growth rate

Effect of Ich on razorback sucker growth rates

We13 evaluated13 growth13 rates13 of razorback sucker13 in the13 presence13 and absence of the

ectoparasite13 Ich (Ichthiopthirus multifiliis) Ich outbreaks can occur in wild populations13 but

hatcheries13 have13 proven excellent locations13 for Ich because13 of very high fish densities13 which13

facilitate13 the13 transfer13 of Ich13 between13 fish This common fish parasite causes direct mortality13

to razorback13 suckers as well13 as secondary bacterial13 infections13

The open spring and13 ditch13 which13 provides water to the Bubbling13 Ponds Hatchery

has long13 been infested with mosquitofish (Gambusia affinis) that harbor13 the13 Ich parasite13

and allow13 it13 to enter the hatchery with incoming13 water13 The solution13 to13 the13 Ich problem13

was to remove the mosquitofish host using13 Rotenone Razorback13 sucker growth13 rates were13

then tracked in13 the absence of this parasite for 4 months and compared with growth rates

after Ich returned to the pond and from13 previous years

Methods

Razorback growth rate in lined ponds

On May 14 2008 141 razorback suckers were tagged with 12 mm PIT tags (1342

kHz) and placed in Pond 3 (approximately 1100000 gallons13 Figure13 4)13 at Bubbling13 Ponds

Fish Hatchery Fifty-shy‐three of these tags were recovered two months later when a large

Ichthyophthirius multifilis (Ich) outbreak killed many fish in the pond On October 15 2008

an additional13 145 PIT tagged13 fish were13 also placed into Pond13 3 On13 May13 14 2009 Pond13 3

was harvested and a total13 of 141 PIT tagged fish were recovered13 Of the tagged fish13 26 fish

had13 been13 in the13 pond since May13 of 2008 (378 days13 o growth) and 115 had been13 in13 the

39

13 40

pond since October13 15 2008 (211 days13 of growth) Numbers of fish in Pond 3 after the Ich

outbreak and for the majority of the period of growth were between 3 000 and 4000 fish

A Hobotempreg temperature13 logger13 was13 also13 installed13 in Pond 3 one meter below the water

surface13 near13 the13 outflow and13 recorded water temperature every 3 hours to allow analysis

of the effects of water temperature on growth rate (Figure13 5) This Hobotemp data is

representative of other pond temperatures throughout this study

In a second experiment 210 adult13 razorback suckers13 were13 PIT tagged13 on13 May 14

2009 and13 placed13 into13 Pond13 3 upper to13 evaluate13 growth13 rates13 of larger13 razorback suckers13 at

Bubbling13 Ponds Hatchery13 under current13 rearing13 conditions13 Size of these fish at tagging13

was (mean = 285 mm range = 205 ndash 396 mm) These fish remained in the pond for 257

days and were harvested on Jan 25 2010 to provide information on growth rates of larger

razorback suckers13 under13 current rearing conditions

Figure 513 Temperatures (degC) inrearing pond at BubblingPonds Hatchery from July toSept 2009 (top graph)13 andfrom Nov to Dec 2009 (Lowergraph) Temperaturesrecorded with a Hobotempregremote data logger13 every 3hours

13

Growth rate13 in an unlined pond

To document razorback sucker growth in earthen ponds we introduced13 225 tagged13

razorback suckers13 into13 Pond13 1 lower13 (Figure 4) in February 3 2010 Additional tagged fish

from13 other studies were added to the pond throughout the growing season and the density

of 1 lower reached a maximum13 of nearly 7000 fish in early summer 2010 Density was

reduced to approximately 6000 fish by capturing fish with hoop nets on June 3 2010 54 of

these fish were tagged fish and returned to 1 lower after being weighed and measured The

pond was harvested on January13 2713 2011 and a total13 of 254 tagged fish out13 of 4296 fish

total were removed from13 the pond The pond was harvested on January 27 2011 (358 days13

of growth) and the tagged fish were weighed and measured Total number of razorbacks in

the pond at harvest13 was 4296

Effect of sorting practices on growth rates

On March 1113 200913 Pond13 5 upper was13 harvested13 and13 split into13 two13 separate13 groups

Two hundred of the smaller fish (average size = 122 mm TL) were PIT tagged and placed

into13 Pond13 7 upper and13 200 of the13 larger13 fish (average = 160 mm TL) were PIT tagged and

placed int Pond13 8 upper Density13 in Pond13 7 was13 4500 fish and13 in Pond13 8 there13 were13 6500

fish These ponds were then harvested after 1 year and growth rates were compared to

give information on the effects of current sorting practices Hobotempreg temperature

loggers were installed in13 Ponds 7 and13 8 during13 the13 grow-shy‐out period with13 water13

temperature recorded every 2 hours13 (Figure13 6)

Effect of Ich on razorback sucker growth rates

Bubbling Ponds spring was treated with Rotenone (CFT Legumine 5) at a

concentration of 2 ppm13 to remove all mosquitofish from13 the spring The treatment

consisted of two treatments 6 hours in duration on two consecutive days (April 12 -shy‐ 13)

using13 drip13 stations13 and13 backpack sprayers13 followed13 by13 an13 additional 6 hours13 of

detoxification using sodium13 permanganate Although 12 mosquitofish were captured in the

spring pond the week following the treatments subsequent minnow trapping (20 traps

checked13 daily13 for 3 weeks) did not capture any additional fish until August 11 2010 when

41

13

juvenile mosquitofish were again detected in the spring pond Minnow traps have

subsequently been set daily with several hundred individuals removed To evaluate if Ich

was also again present in the spring we captured 15 mosquitofish from13 the spring pond on

three separate days and placed them13 in an aquaria at 25 degC with 5 longfin dace known to be

free of Ich These fish were monitored for 2 weeks with no signs of Ich developing This

indicates that even though mosquitofish have returned to the spring pond the parasite is no

longer present13 although how13 long13 this condition13 will13 persist13 is unknown13

On May 1113 201013 200 juvenile razorback13 suckers were harvested out13 of Pond 5

upper (2009 year Class from13 Dexter National Fish Hatchery) and were PIT tagged and

placed into Pond 8 to evaluate if growth rates at bubbling ponds hatchery have improved

following the renovation of the spring and the removal of the Ich parasite Unfortunately13

on Sept13 8 2010 Ich was13 again13 detected13 in Pond 8 and the pond was immediately seined

and 74 tagged fish were measured to obtain growth information for the 4-shy‐month period

during13 which13 the13 pond13 was13 Ich-shy‐free13

Figure13 6 Temperatures (degC) in rearingponds 7 and 8 at Bubbling Ponds Hatchery13 from March 2009 ndash March 201013 pond 7(top13 graph)13 and13 pond 8 (Lower13 graph)13 Temperatures recorded with a Hobotempregremote data logger every 3 hours

42

13

Results

Growth in Lined Ponds

Razorback suckers13 that had been13 in13 Pond 8 upper for the13 entire13 year13 grew an13

average of 0263 mmday (789 mmmonth) and razorback suckers that had been in the

pond for 7 months (Oct -shy‐ May) grew13 on13 average of 028 mmday (843 mmmonth) (Figure13

7) These growth13 rates13 did not significantly13 differ Fish density13 in Pond 3 during13 the13

majority of the growth period was13 00032 ndash 00036 fishgallon13 Additionally no13 significant

differences in growth rate were observed between fish smaller than 210 mm TL and fish

larger than 210 mm TL when all recaptured fish were combined

We also measured the growth rate of very large fish in a lined pond On Jan13 2513 201013

156 adult fish with PIT tags were recovered from13 Pond 3 upper13 These fish were13 in the13

pond for 257 days and experienced an average13 growth13 rate13 of 024mmday or 73

mmmonth (Figure13 7)13 This growth13 rate13 is slightly13 lower13 than13 the13 average13 growth13 rate13

observed13 at Bubbling13 Ponds Hatchery in other studies (0275 mmday 825 mmmonth)

but may not be biologically meaningful We would expect larger13 fish to13 have13 reduced

growth rates according to a typical Von Bertalanfy growth model (Bertalanffy 1957) but it

appears that13 over the size range we evaluated (300 -shy‐ 450 mm TL) growth rates have not

slowed significantly compared to that of smaller13 fish grown at Bubbling Ponds13 Hatchery

Growth13 of razorback suckers13 is known13 to13 slow as13 fish reach13 larger13 sizes but it appears13 this13

reduced growth rate may not really start to be biologically meaningful at Bubbling Ponds

Hatchery13 until razorback suckers13 exceed 450 mm TL

Growth in unlined ponds

Growth13 rates13 for the13 fish recaptured13 during13 the Pond 1 lower13 thinning13 (120 days13 in

the pond) was 024 plusmn 003 mmday (729 plusmn 090 mmmonth) (Figure13 8)13 Fish13 that were13 in

the pond for nearly the entire year grew13 an13 average13 of 024 plusmn 001 mmday (726 plusmn 027

mmmonth) These growth rates are surprisingly the lowest measured growth rates for

any part of our study and differ significantly from13 every other measured growth rate

except very large13 fish (Figure13 9)13 Separating13 out13 large fish that13 were in13 the pond for the

entire year makes no difference fish that were added to the pond at TL lt300 mm grew

43

13

Gro

wth

Rat

e (m

md

ay)

020

026

032

0244 plusmn 001 mmday (733 plusmn 028 mmmonth) and and those with TL gt= 300 mm at the

start of the experiment grew 022 plusmn 003 mmday (651 plusmn 101 mmmonth)

Razorback Growth Rates in Lined Ponds

Figure 7 Growth ofrazorback suckers in(mmday plusmn standard error)in Pond 8 upper in 2008-shy‐2009 An ANOVA did notdetect any significantdifferences

7 Months Full Year 300+ mm fish

Effects of sorting on growth

One hundred and seventy five tagged razorback suckers were recovered from13 Pond

8 upper13 on March13 24 2010 (378 days13 of growth)13 These were13 the13 larger sorted13 fish (gt140

mm TL) that came out of Pond13 5 on March13 11 2009 One13 hundred and13 twenty13 two13 tagged13

razorback suckers were also recovered from13 Pond13 7 upper on March13 31 2010 (385 days13 of

growth)13 These were13 the13 smaller sorted13 fish (lt140 mm TL) that came out of Pond13 5 on

March 1113 200913 No significant differences in growth rate (mmday) were observed among

larger fish in Pond 8 and smaller fish in Pond 7 (pgt005 ANOVA) (Figure 10)13 indicating

that13 sorting may have helped to offset the original slower growth trajectory of the smaller

fish Temperatures of Ponds 7 and 8 upper remained similar throughout the year13 (Figure

5)

44

13

13

13

Gro

wth

Rat

e (m

md

ay)

Gro

wth

Rat

e (m

md

ay)

020

026

032

020

026

032

Razorback Growth in an Unlined Pond

Figure 8 Growth of razorbacksuckers (mmday plusmn standard error) in Pond 1 lower (an unlined pond)in 2010-shy‐2011 An ANOVA did notdetect any significant differences

6 Months 12 Months lt 300 mm Fish 300+ mm Fish Growth Growth

Lined vs Earthen Ponds 1 year of growth

Figure 9 Growth of razorbacksuckers (mmday plusmn standard error) in lined and unlined ponds A t-shy‐test13 did not detect a significantdifference

Lined Pond Unlined Pond 1 Yr Growth 1 Yr Growth

45

13

Effect of Sorting G

row

th R

ate

(mm

day

) G

row

th R

ate

(mm

day

)

032

020

026

032

020

026

Smaller Fish Larger Fish

Effect of Ich

Figure 10 Average growthof razorback suckers(mmday plusmn standard error)that were size-shy‐sorted intosmall fish (pond 7) and largefish (pond 8) populations At-shy‐test did not detect asignificant difference

Figure 11 Average growth ofrazorback suckers (mmday plusmnstandard error) after Ich wasremovd from the hatcheryrsquos springand after Ich was again detected inthe pond The growth rate withoutIch is significantly higher than boththe rate after Ich and the ourstudyrsquos average annual growth ratein lined ponds (ANOVA p =00003)

Growth without Ich Growth With Ich Average Annual 4 months 4 months Growth Rate

46

13

Effect of Ich on razorback sucker growth rates

Seventy-shy‐four13 tagged13 razorback suckers13 were13 recovered from13 Pond 8 on September

15 2010 These fish had13 been13 in the pond for 4 months and experienced a growth rate of

032 mmday or 97 mmmonth (Figure13 11)13 This growth13 rate13 is significantly higher (p =

005 two sample t-shy‐test) than the mean growth rate for the same group13 of tagged fish after

Ich detection (022 mmday or 65 mmmonth) and significantly higher than any other

individual growth13 rates13 observed13 to13 date13 at Bubbling13 Ponds Hatchery13 (Figure13 11)13 If this13

growth13 rate13 were13 extended throughout13 the entire13 year13 fish on average from13 Ich-shy‐free13 ponds13

would be 16 mm longer than fish from13 ponds infested with Ich Studies conducted at

Bubbling Ponds hatchery in 2008 (Ward 2008) did not reveal any effects of the treatment

chemicals on razorback sucker growth rates so it13 is likely that13 the parasite outbreaks

themselves are causing reducing growth rates rather than the chemicals used to treat the

parasites13

Conclusions

Our results suggest that under typical hatchery operations (maximizing number of

fish produced)13 the growth13 rate13 of razorback13 suckers13 is relatively13 consistent at Bubbling13

Ponds hatchery13 at 02-shy‐03 mmday (6-shy‐9 mmmonth)13 but is lower than growth13 rates13 at

other13 facilities (02 ndash 18 mmday Ward et al 2007)13 This growth13 rate13 has13 been13 constant in

both lined and unlined ponds and at all fish densities we were able to measure To achieve13

growth13 rates13 substantially higher than this will likely require13 significant changes in rearing

practices that may not be practical in order to reach numerical production13 goals

Temperature is a key variable in fish growth but seasonal growth patterns

described13 above13 (Figure13 5) demonstrate that water temperatures are high enough in

winter to maintain razorback growth Differences in water temperature by season

currently13 do not fluctuate more than 10degC at Bubbling Ponds because of the continuous

supply of water flowing through each pond (approx 225 gallonsmin) These high water

flows appear to keep pond temperatures within the thermal preference13 for razorback

suckers13 (1213 -shy‐ 28 degC Bulkley and Pimentel 1983) throughout the entire year with

temperatures rarely dropping13 below 16deg13 C (Figures 513 6)13

47

13

Fish density is another key variable in fish growth and though the number of fish in

a pond during our study ranged from13 3000 to 700013 fish we13 did not find any13 correlation13

between13 density and growth rate13 This might yield two conclusions First13 razorback

growth13 may be changed equally13 by13 densities13 at the13 hatchery13 (ie13 a density13 of 3000 fish in a

pond is as stressful13 for razorbacks as a density13 of 7000 fish) An alternative is that other

factors13 such as disease outbreaks have13 stronger13 control over fish growth13 than13 density13

Fish density13 would13 have13 to13 be13 experimentally manipulated to test13 this13 and hatchery

operations (producing the maximum13 number of fish) prevented our manipulating density13

in ponds for this13 work The trouble with manipulating density demonstrates the difficulties

associated with changing13 hatchery13 practices experimenting with density would have

prevented BPH from13 meeting13 production13 goals Given that the stocking of smaller

razorbacks has met with very little success perhaps BPH goals could be changed from13

producing 12000 fish at 300+ mm per year to a smaller number of very large fish each

year Growing13 fewer13 larger13 fish could potentially be accomplished in the same time frame

as more smaller fish but a better understanding of how density alters growth rate would

be required to be confident13 of this

The very slow growth13 in the13 earthen13 unlined13 Pond 1 lower13 was very surprising We13

had13 anticipated13 that the13 diversified diet13 cover and13 other13 habitat features13 provided by13

unlined ponds would yield dramatically increased growth rates However these traits were

not enough to offset high fish densities and in fact the unlined pond in our study13 suffered

mortality to bring densities down to that observed normally in lined ponds

Our data13 suggest13 that razorbacks13 sucker13 growth13 rates13 are13 higher in lined13 ponds13

However we13 think the reasons13 for the13 very slow growth we observed13 in the13 unlined13 pond13

in our study13 is instead13 linked13 to13 the13 usage13 of Pond 1 lower13 during13 the13 study13 rather13 than13

intrinsic13 slow growth13 in earthen13 ponds First the pond was at extremely high density for at

least part of the study The volume of Pond 1 lower has not been estimated but hatchery

managers suggest 1500-shy‐2000 fish is an appropriate number of individuals so this pond

was at a very high density for much of the experiment Second dissolved oxygen is often

very low in the13 large13 earthen13 ponds during the heat of summer much lower than that of

lined ponds This will both limit the number of fish that can survive in the pond and almost

certainly13 increases stress13 of these13 fish potentially13 reducing growth13 The DO crashes also13

48

13

limit the amount of feed hatchery managers can give fish in these ponds sometimes for

days or weeks at a time which further reduces growth during warm13 weather

Our data13 suggests that13 growth rates at the Bubbling13 Ponds Fish Hatchery are likely

as high as possible given13 the pond densities required to meet production goals and the Ich-shy‐

infested water that feeds the facility Sorting practices are successful in helping as many

fish as possible reach stocking length as fast as possible Unlined ponds may be able to

grow13 large13 fish at low13 densities13 but whatever factors allow13 for that13 growth are not13 able to

overcome high fish density The removal of invasive13 fis that act as13 a host for the13 parasite13

Ich fish from13 the Bubbling13 Ponds spring13 allowed the highest13 growth rate at 032 mmday13

(96 mmmonth) but that growth rate decreased again as Ich re-shy‐infested13 the13 hatchery13

Consistently13 achieving13 growth13 rates13 as high or substantially13 higher than13 this13 will likely13

require13 significant changes in rearing practices that may not be practical in order to13 reach13

numerical production13 goals

Two major changes that might result in higher growth rates are substantially

reducing fish density and modifying the way spring water is delivered to the facility (via

either repeated chemical treatments or enclosed concrete water diversions) to eliminate

Ich from13 the hatchery source water Other potential changes not address by our work

include13 flow-shy‐training razorbacks much previous literature including MSCP-shy‐funded13 work

on razorback suckers13 suggests13 that fish growing13 in flowing water will grow13 faster than fish

in still water (Jorgensen and Jobling 1994) Furthermore there are a wide variety of

potential benefits associated with growing13 fish13 in flowing13 water in addition13 to increased

growth13 rates13 (Davidson13 199713 Castro13 et al13 2011) Another option13 for increasing13 growth13

rates13 include13 changing to13 intensive13 culture13 in large circular13 tanks

Finally given that the stocking of smaller razorbacks has met with very little

success13 perhaps13 BPH13 goals13 could13 be13 changed from13 producing 12000 fish at 300+ mm per

year to a smaller number of very large fish each year Growing fewer larger fish could

potentially be accomplished in the same time frame as more smaller fish but a better

understanding13 of how density13 alters growth13 rate13 would13 be13 required to13 be13 confident of this

49

13

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower13 Colorado13 River Multi-shy‐Species13

Conservation Program13 (LCRMSCP) under Work Task C10 We13 thank Ty Wolters13 Tom13

Burke13 and Eric13 Volkman for their support of this research and Frank Agygos and Dave

Billingsly13 of the Bubbling13 Ponds Fish Hatchery13 for their willingness to participate in13 this

research13 and13 for their technical assistance We also thank the LCRMSCP fish group from13

Boulder City13 NV for their assistance with harvesting13 ponds and tagging13 fish13

50

13

Literature13 CitedAnders P J 1998 Conservation aquaculture and endangered species can objective science13

prevail13 over risk13 anxiety Fisheries 23(11) 28-shy‐31

Anderson R O and R M Nuemann 1996 Length weight and associated structural indicesPages 447 ndash 482 in B R Murphy13 and D13 W Willis13 editors13 Fisheries techniques13 2ndedtion American Fisheries13 Society13 Bethesda13 Maryland

Bain M B J T Finn and H E Brooks 1988 Streamflow regulation and fish communitystructure13 Ecology13 69382-shy‐392

Bays J H Zarbock R Whitman and T Murphy 2005 Conceptual design and managementof native13 fish refugia on the13 lower13 Colorado13 River In13 CL Spring13 and13 S Leoneditors Proceedings of two symposia Restoring native fish to the lower ColoradoRiver13 interactions13 of native and non-shy‐native13 fishes 13ndash1413 July13 1999 Las13 Vegas13 Nevada13 Restoring13 natural function within a modified riverine environment thelower Colorado River13 8ndash913 July13 1998 U S Fish and13 Wildlife13 Service Southwestern13 Region Albuquerque New Mexico Pages 167-shy‐177

Bertalanffy L Von 1957 Quantitative laws in metabolism13 and growth13 Q Rev Biology 32217 ndash 231

Bingham T B Scheer and C McAda 2003 Propagation facilities in Grand Valley (24 RoadHatchery Horsethief13 Ponds and13 grow-shy‐out ponds) for captive13 rearing13 ofendangered13 fishes for the13 upper13 Colorado13 River basin13 Colorado River RecoveryProgram FY2003 annual project report13 US Fish and13 Wildlife13 Service GrandJunction13 4pp

Birchell G J and K Christopherson 2004 Survival growth and recruitment of larval andjuvenile razorback13 sucker (Xyrauchen texanus) introduced13 into13 floodplain13 depressions13 of the13 Green River Utah13 Final report13 Upper13 Colorado13 RiverEndangered Fish Recovery Program13 Project No C-shy‐6RZ Publication Number 04-shy‐1513 Utah13 Division of Wildlife13 Resources Salt Lake13 City13 Utah13 67 pages

Brannon E L 1993 The perpetual oversight of hatchery programs Fishery Research 1819-shy‐27

Brett J R 1979 Environmental Factors and growth pages 599-shy‐67513 InW S Hoar13 D13 J13 Randall and J R Brett (eds) Fish Physiology Volume 8 Bioenergetics and GrowthAcademic Press New York

Brooks J E 1986 Annual reintroduction and monitoring report for razorback suckerXyrauchen texanus in the Gila River Basin Arizona 1985 US Fish and WildlifeService13 Offices of Endangered13 Species and Fishery13 Resources Albuquerque 23 pp

51

13

Brunson13 R E and K D13 Christopherson13 200513 Larval13 razorback13 sucker and bonytailsurvival and13 growth13 in the13 presence13 of nonnative13 fish in the13 Baeser13 floodplainwetland of the middle Green River Final report prepared for Upper13 Colorado RiverBasin Endangered Fish Recovery Program Project No C-shy‐6-shy‐rz-shy‐bt Publication13 No 05-shy‐26 Utah13 Division of Wildlife13 Resources13 Vernal13 32 pp

Bulkley R V and R Pimentel 1983 Temperature preference and avoidance by adultrazorback suckers Transactions of the American Fisheries Society 112601-shy‐607

Burke13 T13 199513 Rearing13 wild razorback13 sucker larvae in13 lake-shy‐side13 backwaters13 LakeMohave ArizonaNevada Proceedings of the Desert Fishes Council 2635

Busacker G P I R Adelman and E M Goolish13 199013 Growth13 Pages 363 ndash 387 in C BSchreck and p B Moyle editors Methods for fish biology American FisheriesSociety Bethesda Maryland

Castro V B Grisdale-shy‐Helland S J Helland T Kristensen S M Jorgensen J Helgrud13 GClaireaux A P Farrell A Krasnov and H Takle 2011 Aerobic training stimulatesgrowth and promotes disease resistance in Atlantic salmon (Salmo salar)Comparative Biochemistry and Physiology -shy‐ Part A Molecular amp IntegrativePhysiology13 160(2) 278-shy‐290

Czapla T E 2002 Facilities plan for the production of endangered fishes to meet statestocking13 plans13 as13 part of the13 Upper13 Colorado13 River Endangered13 Fish RecoveryProgram Upper Colorado River Basin Recovery Implementation Program US Fishand Wildlife Service13 Denver13 9 pp

Davidson W 1997 The effects13 of exercise13 training on teleost fish a review of recentliterature Comput Biochem Physiol 117A67ndash75

Figiel Jr C R 2005 Annual report fiscal year 2004 Willow Beach National13 Fish HatcheryUS Fish and Wildlife13 Service Willow Beach 17 pp

Figiel Jr C R M E Ulibarri G Carmichael J Seals and J N Hanson 2005 Intensive13 fish13 culture of warmwater native fishes at a coldwater fish hatchery Pages 164-shy‐16613 inProceedings of two symposia restoring native fish to the lower Colorado13 River13 interaction13 of native13 and13 non-shy‐native13 fishes July13 13-shy‐1413 1999 Las Vegas Nevada USFish and Wildlife Service Southwest Region Albuquerque New Mexico

Gerking13 S D 1978 Ecology of freshwater fish13 production13 Halstead Press13 New13 York

Gustafson W and Q Bradwisch 2000 Wahweap operation and maintenance -shy‐-shy‐ UtahColorado River Recovery Program FY 2000 annual project report Project No 29cUtah13 Division of Wildlife13 Resources Page AZ 3pp

52

13

Hamman R L 1985 Induced spawning of hatchery-shy‐reared13 razorback sucker ProgressivFish Culturist 47(3) 187-shy‐189

Hanson J N 1996 Annual report fiscal year 1996 Willow Beach National Fish HatcheryUS Fish and Wildlife Service13 Willow Beach 9pp

Irving D S Seversen and M Montagne 2004 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2004 annual project13 report Report No 29b US Fish and13 Wildlife13 Service Vernal 3pp

Jorgensen E H and13 M Jobling 1994 Feeding and13 growth13 of exercised13 and13 unexercised13 juvenile Atlantic salmon in freshwater and performance after transfer to seawaterAquaculture International 2 154-shy‐164

Kaeding L R and D B Osmundson 198913 Colorado13 Squawfish13 and13 razorback sucker grow-shy‐out pond studies as part of conservation measures for the green mountain andRuedi reservoir water sales Final report for agreement number 6-shy‐AA-shy‐60-shy‐00150

Koebele13 B P13 198513 Growth and the size hierarchy effect an experimental assessment ofthree proposed mechanisms activity differences disproportional food acquisition13 pysiological stress Environmental Biology of Fishes 12 181-shy‐188

Kretschmann A E and L L Leslie 2006 Razorback sucker (Xyrauchen texanus) status13 reproduction and recruitment in Senator Wash Reservoir CA Final Report13 to USBurea of Reclamation Cooperative Agreement No 00-shy‐FG-shy‐34-shy‐ 0009 p 32 ArizonaGame and Fish Department Phoenix

Marsh13 P13 C13 1987a13 Digestive tract13 contents13 of adult razorback suckers13 in Lake13 MohaveArizona-shy‐Nevada Transactions of the American Fisheries Society 116117-shy‐119

Marsh P C 1987b Native fishes at Buenos Aires National Wildlife Refuge and ArizonaState University Research Park Arizona opportunities for management researchand public13 education13 on13 endangered species13 Proceedings of the Desert13 FishesCouncil 1967-shy‐78

Marsh P C 1994 Rearing native Colorado River fishes in golf course ponds Arizona StateUniversity Tempe 22 + pages

Marsh13 P13 C13 200013 Fish population13 status and evaluation13 in13 the Cibola13 High Levee PondFinal report agreement number 99-shy‐FG-shy‐30-shy‐00051 US Bureau of ReclamationBoulder City13 Nevada13 20 pages

Marsh P C and C A Pacey 1998 Growth of wild adult razorback suckers13 in Lake13 Mohave13 Arizona-shy‐Nevada13 Final report13 US Bureau of Reclamation Boulder City Nevada 25pages + appendices

53

13

Marsh P C B R Kesner and C A Pacey 2005 Repatriation as s management strategy13 to13 conserve a critically13 imperiled fish species North American Journal of FisheriesManagement 25 547-shy‐556

Marsh P C and C A Pacey 2005 Immiscibility of native and non-shy‐native13 fishes Pages 59-shy‐63 inMJ13 Brouder13 CL13 Springer13 and CS13 Leon13 editors13 Proceedings of two13 symposia Restoring native fish to the lower Colorado River interactions of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 NV and13 Restoring natural13 function within a modified riverine environment the lower Colorado River13 July13 8-shy‐913 1998 Las Vegas NV US Fish and13 Wildlife13 Service Southwest Region AlbuquerqueNew Mexico

Marsh13 P13 C13 and J13 E Brooks13 198913 Predation13 by ictalurid catfishes as a deterrent13 toreestablishment of hatchery-shy‐reared13 razorback sucker The Southwestern Naturalist34188-shy‐195

Matthews R A 2005 Ichthyopthirus multifiliis Fouquet and Ichthyopthirosis infreshwater13 teleosts13 Pages13 159-shy‐218 in Advances in Parasitology volume 59 J RBaker R Muller D Rollinson (eds) Academic Press

McCarthy13 M S and W L Minckley 1987 Age estimation for razorback sucker (PiscesCatostomidae) from13 Lake Mohave Arizona and Nevada Journal of the Arizona-shy‐Nevada Academy of Science 2187-shy‐97

Minckley13 W L13 198313 Status of the razorback13 sucker13 Xyrauchen texanus (Abbot)13 in13 thelower Colorado River basin13 The Southwestern13 Naturalist13 28(2) 165-shy‐187

Minckley13 W L13 199113 Native fished of the Grand Canyon13 region an obituary13 Pages 124-shy‐177 in Colorado River ecology and dam13 management National Academy PressWashington13 DC

Minckley13 C13 O and M LaBarbara13 199913 Report13 on13 native fish grow-shy‐out facilities13 at Cibolaand Imperial National Wildlife Refuges 1993-shy‐199513 US Fish and13 Wildlife Service13 Parker Fishery Resources Office Parker Arizona

Modde13 T13 199613 Juvenile razorback sucker (Xyrauchen texanus) in a managed wetlandadjacent13 to the Green13 River13 Great13 Basin13 Naturalist13 56375-shy‐376

Modde T KP Burnham and E J Wick 1996 Population status of the razorback sucker13 inthe middle Green River (USA) Conservation13 biology 10 110-shy‐119

Modde13 T13 and G13 B Haines13 200513 Survival13 and growth of stocked razorback13 sucker andbonytail in multiple floodplain wetlands of the middle Green River under resetconditions13 Final report prepared for Upper Colorado13 River13 Basin RecoveryImplimentation Program US Fish and Wildlife Service Vernal 66 pp

54

13

Modde T Z H Bowen and D C Kitcheyan 2005 Spatial and temporal use of a spawning13 site in the middle Green River by wild hatchery-shy‐reared13 razorback suckers13 Transactions of the American Fisheries Society 134937-shy‐944

Mueller13 G13 199213 The native fish work13 group13 -shy‐ a multiagency endeavor to improve thestatus of the razorback sucker in Lake Mohave AZ-shy‐NV13 Proceedings of the DesertFishes Council 2369

Mueller G 1995 A program13 for maintaining the razorback sucker in Lake MohaveAmerican Fisheries Society Symposium 15127-shy‐135

Mueller13 G13 200613 Ecology of the bonytail13 and razorback13 sucker and the role of offchannelhabitats13 in their13 recovery Scientific13 investigations13 report 2006-shy‐5065 US GeologicalSurvey13 Denver

Mueller G and E Wick 1998 Testing of golf course ponds at Page Arizona for suitability13 as grow-shy‐out facility for razorback sucker using surplus fish from13 Ouray NationalFish Hatchery National Park Service US Fish and13 Wildlife13 Service and UtahDivision of Wildlife13 Resources 28 pages

Mueller13 G13 and T13 Burke13 200513 Survival13 of young13 razorback13 sucker (Xyrauchen texanus) inrelation to13 stocking rates13 (fishha)13 and13 in the presence13 or absence13 of predatorcommunities in Lake Mohave Arizona-shy‐Nevada13 Pages13 155-shy‐16313 in Proceedings of two13 symposia restoring native fish to the lower Colorado River interaction13 of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 Nevada US Fish and Wildlife13 Service Southwest Region Albuquerque New Mexico

Mueller13 G13 J13 Carpenter13 and P13 C13 Marsh13 200413 Cibola13 High Levee Pond annual report 2004US Geological Survey Fort Collins13 Science Center13 Colorado13 and Arizona StateUniversity Tempe 23 pages

Nesler T P K Christopherson J M Hudson C W McAda F Pfeifer and T E Czapla 2003An integrated stocking plan for razorback sucker bonytail and Colorado13 pikeminnow for the Upper Colorado River Endangered Fish Recovery ProgramAddendum13 to State Stocking Plans Upper Colorado River Basin Recovery13 Implementation Program 12 pp

Papoulias13 D and W13 L Minckley13 1992 Effects13 of foo availability13 on survival and growth13 of larval razorback suckers13 in ponds Transactions of the American Fisheries Society121340-shy‐355

Paukert13 C P D L Ward13 P J Sponholtz13 and K13 D Hilwig13 Effects13 of repeated hoopnetting13 on bonytail chub13 Journal of Freshwater13 Ecology13 20(4) 649-shy‐653

Pfeifer F M13 C Baker13 and M13 Montagne13 199913 Propagation13 facilities13 in the13 Grand Valley13 (24 Road13 Hatchery13 Horsethief13 Ponds and13 grow-shy‐out ponds) for captive rearing of

55

13

endangered13 fishes for the13 Upper Colorado13 River Basin13 Colorado13 River Recovery13 Program FY 99 annual project report Project No 29a13 US Fish and Wildlife Service13 Grand13 Junction13 5pp

Pfeifer F S Seversen and M Montagne 2003 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2003 annual reportProject No 29b13 US Fish and Wildlife13 Service Vernal13 4pp

Rabago-shy‐Castro J L Sanchez13 J G Perez-shy‐Castaneda R and13 Gonzalez-shy‐Gonzlez A 2006Effects of the prophylactic use of Romet-shy‐3013 and13 copper13 sulfate13 on growth13 condition13 and feeding13 indicies in13 channel13 catfish (Ictalurus punctatus) Aquaculture 253 343-shy‐349

Reinitz GL L E Orme and F N Hitzel 1979 Variations of body compositio and growth13 among strains of rainbow trout Transactions of the American Fisheries Society 108204-shy‐207

Ruppert13 J13 B P B Holden13 and P D Abate 1999 Age estimation and growth of razorbacksucker13 Xyrauchen texanus in Lake13 Mead Nevada Proceedings13 of the Desert FishesCouncil 3040

Schnoor K D and J Logan 2002 Operation and maintenance of JW Mumma nativeaquatic13 species restoration facility Colorado Colorado River Recovery Program FY2002 annual project report13 Project No 29d Colorado13 Division of Wildlife Alamosa3pp

Salisbury13 L13 1998 Factors13 affecting razorback13 sucker growth13 in Lake13 Mohave backwaters13 MS Thesis13 Unviersity13 of Nevada13 Las13 Vegas

Schooley J13 D13 and P C13 Marsh13 2007 Stocking of endangerdd13 razorback13 suckers13 in thelower Colorado River Basin13 over three decades 1974-shy‐2004 North American Journalof Fisheries Management 27 43-shy‐51

Severson S H H M Tyus and G B Haines 1992 An evaluation of feeds for raisingrazorback sucker Xyrauchen texanus Journal of Applied Aquaculture 155-shy‐65

Toney D P 1974 Observations13 on the13 propagation13 and13 rearing13 of two13 endangered species13 in a hatchery environment Proceedings of the Annual Conference of the Western13 Association of State Game and Fish Commissions 54 252-shy‐259

Tyus H M13 1998 Razorback sucker13 (Xyrauchen texanus) recovery plan13 University13 ofColorado Center for Limnology Boulder13 76 pages

Tyus H M13 and13 S H Severson 1990 Growth13 and13 survival of larval razorback suckers fedfive formulated diets The Progressive Fish Culturist 52197-shy‐200

56

13

Ulibarri M E 2003 Annual report fiscal year 2001 Dexter National Fish Hatchery13 andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 26 pages

Ulibarri M E 2003 Annual report fiscal year 2002 Dexter National Fish Hatchery andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 59 pages

USBR 2006 Lower13 Colorado13 River Multi-shy‐Species Conservation Program final fishaugmentation plan Boulder City 19 pp

USFWS 2002 Razorback sucker (Xyraouchen texanus) recovery goals Amendment andsupplement to the Razorback Sucker Recovery Plan13 US Fish and Wildlife Service13 Region 6 Denver13 Colorado

USFWS 1999 Annual report 1999 Ouray National Fish Hatchery Vernal 25pp

USFWS 2004 Management plan for the big-shy‐river13 fishes of the13 lower13 Colorado13 river basinamendment and supplement to the bonytail humpback chub Coloradopikeminnow and razorback sucker recovery plans

USFWS13 2005 Station13 profile13 of the13 Dexter13 National Fish Hatchery13 and Technology CenterUS Fish and Wildlife13 Service Dexter

Valdez R A P G Mangan R Smith and B Nilson 1982 Upper Colorado River fisheriesinvestigations13 inW H Miller J J Valentine D L Archer H M Tyus R A Valdezand L13 Kaeding13 editors13 Colorado River Fishery13 Project13 Part 2 Field13 investigations13 US Bureau of Reclamation Salt Lake City Utah

WBNFH 2004 Culture methods of the endangered razorback sucker Xyrauchen texanusUS Fish and Wildlife13 Service Willow Beach National Fish Hatchery13 8 pp

Ward D 2008 Effects of disease treatments on growth of razorback sucker ReportSubmitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 Inpartial fulfillment of work task C10 agreement number 06FG30039

Ward13 D13 M Childs and W Persons 2007 Factors13 affecting13 growth13 of razorback sucker13 (Xyrauchen texanus) in captivity Literature review and knowledge assessmentReport Submitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 In partial fulfillment of work task C10 agreement number 06FG30039

57

Appendices

Appendix 1 Survey Questions Survey of Razorback Sucker Culture in the

Southwestern United States

The enclosed survey is being distributed by the Arizona Game and Fish Department to razorback sucker culture facilities throughout

the Southwestern United States The purpose of this survey is to consolidate information regarding culture of this species so that

appropriate facility improvements can be considered for Bubbling Ponds Hatchery in Arizona Specifically we wish to increase

growth rate and production efficiency at the hatchery Information gathered in this survey will be summarized in a final report to US

Bureau of Reclamation in Boulder City NV and disseminated to all facilities that participate in the survey A workshop to discuss

the findings of this study as well as to share general information concerning razorback sucker culture will be organized by the

Arizona Game and Fish Department at the conclusion of this study and all participants will be invited

Thank you for taking the time to fill out this survey Please contact Mike Childs if you have questions or would like to discuss the

survey

Mike Childs

mchildssedonanet

(928) 639-1346

(928) 634-1279

Facility_____________________________________ Date___________________

Contact Phone _____________________________

ContactPerson_______________________________

Contact Email _______________________________

1 Water quality ranges at this culture facility

Season

Spring (Mar-May) Summer (Jun-Aug) Fall (Sept-Nov) Winter (Dec-Feb)

Temperature (C)

PH

DO (mgL)

PO4 (mgL)

TDS (mgL)

Hardness (mgL)

CaCO3

Pathogens

37

13

averaged 179 mm total length (TL) (range13 = 127 ndash 262 mm TL)13 These fish were13 offspring13

of captive13 razorback sucker13 broodstock held13 at Dexter13 National13 Fish Hatchery13 NM13 (2007

year class) All fish were tagged with passive integrated transponder (PIT) tags and

quarantined for one month prior to the experiment to allow fish to recover from13 tagging

and become accustomed to being held in circular tanks

At the beginning of the study all fish were weighed measured and scanned for

individual tag numbers with 19 randomly selected fish placed into each13 of 10 8-shy‐foot

diameter circular tanks (Figure 2)13 Each13 tank contained13 two13 airstones13 and13 an13 individual

biofilter with a recirculating water pump (31 litersminute) that had been operating for

at least 1 month prior to the experiment to allow bacterial colonies to become

established Two tanks were designated as a control and did not receive any chemical

treatments while the other eight tanks received formalin copper sulfate potassium13

permanganate or salt treatments at two week intervals (two tanks per chemical

treatment) Formalin copper sulfate and potassium13 permanganate were treated at 1 part

per million (ppm) and salt was applied at 30 parts per thousand (ppt) These treatment

rates are commonly used to treat13 razorback13 suckers for ich at Bubbling13 Ponds Fish13

hatchery (Frank Agygos personal communication)

Figure 213 Photo ofexperimental tankswith individualbiofilters and aeration

31

13

Each treatment consisted of a series of doses applied on Wednesday Thursday and

Friday with a 90water change between each dose Biofilters were removed from13 all

tanks and held in a separate holding facility during treatments and then replaced on the

Monday following treatments after a 90water change This schedule allowed fish to be

exposed to chemical treatments for 5 consecutive days without water quality deteriorating

This 5-shy‐day chemical treatment was repeated every two weeks from13 July to October (97

days)13 for a total of 5 5-shy‐day treatments Water temperature in the treatment tanks ranged

from13 13degC (55degF) to 32degC (91degF)

Fish were fed a fixed ration of commercial razorback diet (Silvercup 4mm13 pellet)

once daily13 (2 percent body13 weight per day13 as calculated13 by13 average initial fish weight)13

At the end of the experiment all fish were again weighed measured and scanned for

individual tag numbers Growth of fish in each treatment group was compared using

analysis of variance (ANOVA) Any mortalities13 that occurred during the13 study13 were13

replaced with previously quarantined fish of equivalent size to maintain equal densities in

each13 tank13 but growth13 data was13 only13 recorded for fish which13 survived13 the13 entire13

experiment

Results

Fish at the13 start of the experiment averaged 179 mm TL (Range13 = 127 ndash 262 mm)

with no significant differences in fish length among treatment groups (F(4189) = 00183 p

gt 0999 ANOVA) On average fish grew 235 mm TL (024 mmday) during the 3 month

study13 Fish in tanks13 treated with formalin had the highest growth averaging 29 mm TL (03

mmday) while fish in tanks treated with copper had the lowest growth averaging 20 mm

TL (021 mmday) Fish in the control tanks averaged 213 mm TL in growth (022

mmday) (Figure13 3)13 Formalin-shy‐treated fish grew13 significantly faster than13 any other

treatment group but no13 significant differences in growth13 in length13 or weight were13

observed among fish treated with any of the chemicals compared to untreated (control)

fish (pgt005 ANOVA)

32

13

Figure 313 Average growthof razorback suckersexposed to a series of 5 5-shy‐day chemical treatmentsover a 97-shy‐day13 periodError bars representstandard error

Discussion13

Growth13 rates13 observed13 in our study13 (021 ndash 03 mmday) are low compared to those

reported13 in other13 studies13 of razorback sucker13 growth13 (0213 ndash 18 mmday) (Ward et al

2007) Using recirculating water systems for our study required filters to be removed and

replaced during treatments Stress to fish caused by removing and replacing filters within

the tanks as well as repeated water changes may have led to overall higher stress and

reduced growth rates compared to those reported for unconfined fish Growth in fish is

highly variable and is affected by many different physiological and environmental factors

including fish size density temperature amount of space and food (Brett 1979) We

strived to control each of these factors but other factors may have also influenced growth

in our experimental tanks During mid-shy‐summer water temperatures in the treatment

tanks reached 32degC (91degF) At these warm13 temperatures fish are very susceptible to

bacterial13 infections13 The slightly higher growth exhibited by fish in the formalin and

potassium13 permanganate treatments may have been the result of these two chemicals

33

13

being effective at controlling bacterial infections The differences in growth we measured

among treatment groups were not statistically significant and do not appear13 biologically13

meaningful during the relatively short duration of this study (97 days) although the

cumulative effects of slightly reduced growth could be biologically meaningful over longer

time frames

Reductions in growth13 as a result13 o repeated chemical treatments are not likely the

cause of differences in growth rates among facilities that raise razorback suckers

Repeated chemical treatments may have other impacts to overall fitness or long-shy‐term13

survival but these13 effects13 were13 not evident in our study It is more likely that the parasite

outbreaks themselves are the cause of different growth rates among razorback rearing

facilities rather than the chemical treatments used to treat the parasites We recommend

that hatchery managers continue to use the chemicals that are most effective at controlling

ldquoIchrdquo13 at their individual13 facilities

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower Colorado Rive Multi-shy‐species13

Conservation Plan under Work Task C10 We thank Ty Wolters and Tom13 Burke for their

support of this research and Frank Agygos and Dave Billingsly of the Bubbling Ponds Fish

Hatchery13 for their13 technical assistance13 and13 help with13 collecting13 fish

34

13

III13 Razorback Growth Rates at Bubbling Ponds ndash 2009-shy‐2011

Section13 SummaryExperimental studies at Bubbling Ponds Fish Hatchery AZ have strived to understand

factors that affect razorback sucker growth in captivity and identify ways to improve growthrates and maximize size at release Rather than performing experimental studies that wouldrequire major13 rearrangement (and likely reduced production)13 of hatchery operations our13 studies13 used normal variation in production techniques13 and practices13 to isolate factors13 thatmay modify growth rates

Our initial work identified razorback13 growth rates in13 lined ponds at standard fishdensity as 026 to13 028mmday (789 to 843 mmmonth) No significant differences in growthrate were observed among fish that had been in the pond only during the winter13 periodcompared to fish that had been in the pond the entire year indicating that water temperatures13 at Bubbling Ponds are high enough to allow fish to incorporate feed effectively year-shy‐roundHowever these growth rates are lower than most values reported from the literature fromnatural or semi-shy‐natural pond environments No significant differences in13 growth rate wereobserved13 between large and13 small fish13 within the 150 ndash 29 mm TL13 size range Additional worksuggests13 that razorback suckers13 tagged at over 300 mm TL had reduced growth rates (024mmday 73 mmmonth) as would be expected according to a typical Von13 Bertalanfy growthcurve although growth rates13 were only slightly less13 than the average growth rate for thehatchery (027513 mmday 82513 mmmonth)

Sorting13 to13 separate small fish from large fish after the first year of growth is practicedesigned13 to allow smaller fish to ldquocatch uprdquo to larger fish We found that13 this technique doesappear to13 improve growth rates of smaller fish Growth rates of sorted small razorback suckers(029 mmday 87mmmonth)13 were equal to that13 of larger13 fish (028 mmday 8413 mmmonth)indicating that sorting may have helped to offset their original slower growth trajectory

Bubbling Ponds Fish Hatchery grows razorbacks in 6 long deep ponds lined with heavyplastic 2 long deep13 earthen13 (unlined) ponds and three wide shallow earthen ponds The wideshallow ponds13 have historically produced very large fish at low density but have been found tomaintain much lower fish numbers than deeper ponds We found13 that growth13 rates ofrazorbacks kept at high density (4-shy‐700013 fish)13 in a wide shallow pond grew extremely slowly(024 mmday 726 mmmonth) This growth rate is among the slowest of any fish over theyears of our study and demonstrates that13 though the large ponds may produce large fish at lowdensity13 they are unable to overcome high13 fish13 densities

Finally one of the major factors influencing13 fish13 growth13 in hatcheries is disease onemajor summer-shy‐time disease at13 Bubbling Ponds is the ectoparasite Ich (Ichthiopthirusmultifiliis) To investigate the impact Ich has on razorback growth we eradicated fish from thespring and water conveyance ditch that supplies13 water to the hatchery using Rotenone This13 restoration effort was fairly short-shy‐lived (Ich returned to the hatchery within four months) but

35

13

growth13 rates of fish13 reared for four months without Ich present (031 mmday 92 mmmonth)were significantly higher than the following 8 months of growth for those same fish (022mmday 65 mmmonth) This disease-shy‐free growth rate is in fact faster than any13 otherprevious growth rates observed at the hatchery in our study

We conclude that growth rates at the Bubbling Ponds Fish Hatchery are likely as highas possible given the pond densities required to13 meet production goals and the Ich-shy‐infestedwater13 that feeds the facility Sorting practices are successful in helping as many fish as possiblereach stocking length as fast as possible Unlined ponds may be able to grow large fish at lowdensities but whatever factors allow for that growth13 are not able13 to overcome13 high fish densityThus the large lower ponds at Bubbling Ponds may be better utilized via renovation to13 deepenand line them

Disease is the most important factor limiting growth as may be expected to be the caseat many13 hatcheries While the spring renovation was not13 a complete success13 the dramaticreduction of fish populations in that habitat was enough to dramatically13 reduce13 the13 occurrenceof Ich at the hatchery13 Such open spring13 systems feeding a hatchery are a misfortune that canbe expected to transmit disease so we suggest that renovating the spring again to combat13 IchImproved techniques to divert water from13 the springs and more throuough treatment ofstream-shy‐side vegetation may improve the success of chemical treatment Successful renovationwould likely both improve growth rates and reduce chemical costs associated with treating Ichoutbreaks Even13 if complete renovation13 is impossible or impractical an13 effort to reduceinvasive fish density in the springs13 which act a vector for the parasite(and thereby reduce thelikelihood of13 Ich being transmitted into ponds) may still13 show dramatic improvements

36

13

Introduction

Conservation efforts13 for razorback sucker13 (Xyrauchen texanus)13 currently13 depend on

captive rearing and stocking programs Low survival of stocked razorback suckers (Brooks

1986 Marsh13 and13 Brooks13 1989 Marsh13 and13 Pacey13 2005) has13 caused13 target sizes for stocked13

fish to steadily increase in efforts to reduce predation mortality13 (Marsh13 et al13 2005

Schooley and Marsh 2007) Rearing fish to larger sizes at hatcheries comes with increased

costs and creates the need to evaluate husbandry and rearing practices that may affect fish

growth13 We evaluated growth13 rates13 of individual razorback suckers13 in ponds13 at Bubbling

Ponds Fish Hatchery13 using Passive Integrated13 Transponder (PIT) tags13 to13 obtain13 precise

growth information for individual fish so that valid comparisons of growth rates as related

to rearing practices can be made

Due to the critical nature of the razorback sucker stocking program we did not

design experimental studies that would require major rearrangement and potentially

reduce production of hatchery operations Instead our studies used normal variation in

production techniques and practices to isolate factors that may modify growth rates

Though this methodology dramatically limits replication and may limit our ability to

directly13 attribute13 differences in growth13 rates13 to13 the13 variables13 we13 investigate13 we13 were13 able13

to accomplish research goals without altering hatchery operations or impacting

production

From13 2009 through 2011 we conducted a series of observational13 growth13 studies to

determine growth rates of individual razorbacks at Bubbling Ponds The first set of

experiments included13 identifying13 growth13 rates13 in lined13 and13 unlined13 ponds determining

growth13 rates13 of fish at different13 sizes13 in13 relation13 to sorting13 practices and monitoring

razorback growth rates after removing the source of the ectoparasite13 Ich (Ichthiopthirus

multifiliis) from13 the hatchery water source13

Razorback growth rate in lined ponds

Our first growth study documented individual growth rates at normal density in 11

million gallon lined ponds13 over two13 years13 This is the standard13 grow-shy‐out process for

razorbacks13 at Bubbling Ponds We monitored growth of fish for a variety13 of sizes and13 the13

37

13

amount of time in a pond during the growing season These13 data give a snapshot of growth13

rates13 at the13 facility13 and13 provide13 the basis for comparisons throughout our study

Growth rate13 in an unlined pond

In addition13 to 6 ponds lined with heavy plastic13 sheeting13 Bubbling Ponds Fish13

Hatchery maintains two narrow and deep (same dimensions as lined ponds13 Figure13 4)13 and13

three large13 shallow unlined ponds These earthen13 ponds typically have vegetation and

associated aquatic invertebrates that may better simulate natural environments by

providing cover and improved food diversity or quality Therefore these unlined ponds

may be expected to produce higher growth rates and potentially improved survival that is

more similar to growth rates observed in more natural grow-shy‐out facilities13 Historically13 the13

large13 shallow13 ponds have produced very large fish when13 utilized at low13 fish density13 The

narrow13 deep earthen13 ponds are13 used to grow13 fry13 at high density in their first13 year of life

The major downside to unlined ponds is the difficulty in harvesting fish where a lined

pond might take 8-shy‐1013 people13 a half13 day13 to13 harvest13 lined13 ponds13 require13 intensive13 weeding13

to allow seines to be pulled and therefore require many more personnel-shy‐hours13 In addition13

to harvest challenges the shallow earthen ponds tend to suffer from13 dissolved oxygen

crashes during the summer Unlined ponds also may maintain higher13 populations13 of non-shy‐

target species such as bluegill sunfish mosquito fish and bullfrog tadpoles We measured

growth rates of suckers in a large shallow earthen pond for comparison to growth in lined

ponds13

Figure13 4 Lined13 and13 earthen ponds13 of similar dimensions (approx 1000000 gallons first

and second panels) and a large13 shallow13 earthen13 pond (third panel)

38

13

Effect of sorting on growth

Razorback13 suckers13 are13 currently13 sorted13 after their first13 year of growth13 They are13

typically removed from13 one of the13 upper earthen13 ponds and13 split into13 two13 lined13 ponds for

subsequent grow-shy‐out13 The larger13 fish (gt approximately 140 mm) are placed into one pond

and the smaller individuals in another It is possible that the larger fish were more

aggressive or adept13 at taking food so this sorting process is intended to allow smaller fish

to improve their growth rate

Effect of Ich on razorback sucker growth rates

We13 evaluated13 growth13 rates13 of razorback sucker13 in the13 presence13 and absence of the

ectoparasite13 Ich (Ichthiopthirus multifiliis) Ich outbreaks can occur in wild populations13 but

hatcheries13 have13 proven excellent locations13 for Ich because13 of very high fish densities13 which13

facilitate13 the13 transfer13 of Ich13 between13 fish This common fish parasite causes direct mortality13

to razorback13 suckers as well13 as secondary bacterial13 infections13

The open spring and13 ditch13 which13 provides water to the Bubbling13 Ponds Hatchery

has long13 been infested with mosquitofish (Gambusia affinis) that harbor13 the13 Ich parasite13

and allow13 it13 to enter the hatchery with incoming13 water13 The solution13 to13 the13 Ich problem13

was to remove the mosquitofish host using13 Rotenone Razorback13 sucker growth13 rates were13

then tracked in13 the absence of this parasite for 4 months and compared with growth rates

after Ich returned to the pond and from13 previous years

Methods

Razorback growth rate in lined ponds

On May 14 2008 141 razorback suckers were tagged with 12 mm PIT tags (1342

kHz) and placed in Pond 3 (approximately 1100000 gallons13 Figure13 4)13 at Bubbling13 Ponds

Fish Hatchery Fifty-shy‐three of these tags were recovered two months later when a large

Ichthyophthirius multifilis (Ich) outbreak killed many fish in the pond On October 15 2008

an additional13 145 PIT tagged13 fish were13 also placed into Pond13 3 On13 May13 14 2009 Pond13 3

was harvested and a total13 of 141 PIT tagged fish were recovered13 Of the tagged fish13 26 fish

had13 been13 in the13 pond since May13 of 2008 (378 days13 o growth) and 115 had been13 in13 the

39

13 40

pond since October13 15 2008 (211 days13 of growth) Numbers of fish in Pond 3 after the Ich

outbreak and for the majority of the period of growth were between 3 000 and 4000 fish

A Hobotempreg temperature13 logger13 was13 also13 installed13 in Pond 3 one meter below the water

surface13 near13 the13 outflow and13 recorded water temperature every 3 hours to allow analysis

of the effects of water temperature on growth rate (Figure13 5) This Hobotemp data is

representative of other pond temperatures throughout this study

In a second experiment 210 adult13 razorback suckers13 were13 PIT tagged13 on13 May 14

2009 and13 placed13 into13 Pond13 3 upper to13 evaluate13 growth13 rates13 of larger13 razorback suckers13 at

Bubbling13 Ponds Hatchery13 under current13 rearing13 conditions13 Size of these fish at tagging13

was (mean = 285 mm range = 205 ndash 396 mm) These fish remained in the pond for 257

days and were harvested on Jan 25 2010 to provide information on growth rates of larger

razorback suckers13 under13 current rearing conditions

Figure 513 Temperatures (degC) inrearing pond at BubblingPonds Hatchery from July toSept 2009 (top graph)13 andfrom Nov to Dec 2009 (Lowergraph) Temperaturesrecorded with a Hobotempregremote data logger13 every 3hours

13

Growth rate13 in an unlined pond

To document razorback sucker growth in earthen ponds we introduced13 225 tagged13

razorback suckers13 into13 Pond13 1 lower13 (Figure 4) in February 3 2010 Additional tagged fish

from13 other studies were added to the pond throughout the growing season and the density

of 1 lower reached a maximum13 of nearly 7000 fish in early summer 2010 Density was

reduced to approximately 6000 fish by capturing fish with hoop nets on June 3 2010 54 of

these fish were tagged fish and returned to 1 lower after being weighed and measured The

pond was harvested on January13 2713 2011 and a total13 of 254 tagged fish out13 of 4296 fish

total were removed from13 the pond The pond was harvested on January 27 2011 (358 days13

of growth) and the tagged fish were weighed and measured Total number of razorbacks in

the pond at harvest13 was 4296

Effect of sorting practices on growth rates

On March 1113 200913 Pond13 5 upper was13 harvested13 and13 split into13 two13 separate13 groups

Two hundred of the smaller fish (average size = 122 mm TL) were PIT tagged and placed

into13 Pond13 7 upper and13 200 of the13 larger13 fish (average = 160 mm TL) were PIT tagged and

placed int Pond13 8 upper Density13 in Pond13 7 was13 4500 fish and13 in Pond13 8 there13 were13 6500

fish These ponds were then harvested after 1 year and growth rates were compared to

give information on the effects of current sorting practices Hobotempreg temperature

loggers were installed in13 Ponds 7 and13 8 during13 the13 grow-shy‐out period with13 water13

temperature recorded every 2 hours13 (Figure13 6)

Effect of Ich on razorback sucker growth rates

Bubbling Ponds spring was treated with Rotenone (CFT Legumine 5) at a

concentration of 2 ppm13 to remove all mosquitofish from13 the spring The treatment

consisted of two treatments 6 hours in duration on two consecutive days (April 12 -shy‐ 13)

using13 drip13 stations13 and13 backpack sprayers13 followed13 by13 an13 additional 6 hours13 of

detoxification using sodium13 permanganate Although 12 mosquitofish were captured in the

spring pond the week following the treatments subsequent minnow trapping (20 traps

checked13 daily13 for 3 weeks) did not capture any additional fish until August 11 2010 when

41

13

juvenile mosquitofish were again detected in the spring pond Minnow traps have

subsequently been set daily with several hundred individuals removed To evaluate if Ich

was also again present in the spring we captured 15 mosquitofish from13 the spring pond on

three separate days and placed them13 in an aquaria at 25 degC with 5 longfin dace known to be

free of Ich These fish were monitored for 2 weeks with no signs of Ich developing This

indicates that even though mosquitofish have returned to the spring pond the parasite is no

longer present13 although how13 long13 this condition13 will13 persist13 is unknown13

On May 1113 201013 200 juvenile razorback13 suckers were harvested out13 of Pond 5

upper (2009 year Class from13 Dexter National Fish Hatchery) and were PIT tagged and

placed into Pond 8 to evaluate if growth rates at bubbling ponds hatchery have improved

following the renovation of the spring and the removal of the Ich parasite Unfortunately13

on Sept13 8 2010 Ich was13 again13 detected13 in Pond 8 and the pond was immediately seined

and 74 tagged fish were measured to obtain growth information for the 4-shy‐month period

during13 which13 the13 pond13 was13 Ich-shy‐free13

Figure13 6 Temperatures (degC) in rearingponds 7 and 8 at Bubbling Ponds Hatchery13 from March 2009 ndash March 201013 pond 7(top13 graph)13 and13 pond 8 (Lower13 graph)13 Temperatures recorded with a Hobotempregremote data logger every 3 hours

42

13

Results

Growth in Lined Ponds

Razorback suckers13 that had been13 in13 Pond 8 upper for the13 entire13 year13 grew an13

average of 0263 mmday (789 mmmonth) and razorback suckers that had been in the

pond for 7 months (Oct -shy‐ May) grew13 on13 average of 028 mmday (843 mmmonth) (Figure13

7) These growth13 rates13 did not significantly13 differ Fish density13 in Pond 3 during13 the13

majority of the growth period was13 00032 ndash 00036 fishgallon13 Additionally no13 significant

differences in growth rate were observed between fish smaller than 210 mm TL and fish

larger than 210 mm TL when all recaptured fish were combined

We also measured the growth rate of very large fish in a lined pond On Jan13 2513 201013

156 adult fish with PIT tags were recovered from13 Pond 3 upper13 These fish were13 in the13

pond for 257 days and experienced an average13 growth13 rate13 of 024mmday or 73

mmmonth (Figure13 7)13 This growth13 rate13 is slightly13 lower13 than13 the13 average13 growth13 rate13

observed13 at Bubbling13 Ponds Hatchery in other studies (0275 mmday 825 mmmonth)

but may not be biologically meaningful We would expect larger13 fish to13 have13 reduced

growth rates according to a typical Von Bertalanfy growth model (Bertalanffy 1957) but it

appears that13 over the size range we evaluated (300 -shy‐ 450 mm TL) growth rates have not

slowed significantly compared to that of smaller13 fish grown at Bubbling Ponds13 Hatchery

Growth13 of razorback suckers13 is known13 to13 slow as13 fish reach13 larger13 sizes but it appears13 this13

reduced growth rate may not really start to be biologically meaningful at Bubbling Ponds

Hatchery13 until razorback suckers13 exceed 450 mm TL

Growth in unlined ponds

Growth13 rates13 for the13 fish recaptured13 during13 the Pond 1 lower13 thinning13 (120 days13 in

the pond) was 024 plusmn 003 mmday (729 plusmn 090 mmmonth) (Figure13 8)13 Fish13 that were13 in

the pond for nearly the entire year grew13 an13 average13 of 024 plusmn 001 mmday (726 plusmn 027

mmmonth) These growth rates are surprisingly the lowest measured growth rates for

any part of our study and differ significantly from13 every other measured growth rate

except very large13 fish (Figure13 9)13 Separating13 out13 large fish that13 were in13 the pond for the

entire year makes no difference fish that were added to the pond at TL lt300 mm grew

43

13

Gro

wth

Rat

e (m

md

ay)

020

026

032

0244 plusmn 001 mmday (733 plusmn 028 mmmonth) and and those with TL gt= 300 mm at the

start of the experiment grew 022 plusmn 003 mmday (651 plusmn 101 mmmonth)

Razorback Growth Rates in Lined Ponds

Figure 7 Growth ofrazorback suckers in(mmday plusmn standard error)in Pond 8 upper in 2008-shy‐2009 An ANOVA did notdetect any significantdifferences

7 Months Full Year 300+ mm fish

Effects of sorting on growth

One hundred and seventy five tagged razorback suckers were recovered from13 Pond

8 upper13 on March13 24 2010 (378 days13 of growth)13 These were13 the13 larger sorted13 fish (gt140

mm TL) that came out of Pond13 5 on March13 11 2009 One13 hundred and13 twenty13 two13 tagged13

razorback suckers were also recovered from13 Pond13 7 upper on March13 31 2010 (385 days13 of

growth)13 These were13 the13 smaller sorted13 fish (lt140 mm TL) that came out of Pond13 5 on

March 1113 200913 No significant differences in growth rate (mmday) were observed among

larger fish in Pond 8 and smaller fish in Pond 7 (pgt005 ANOVA) (Figure 10)13 indicating

that13 sorting may have helped to offset the original slower growth trajectory of the smaller

fish Temperatures of Ponds 7 and 8 upper remained similar throughout the year13 (Figure

5)

44

13

13

13

Gro

wth

Rat

e (m

md

ay)

Gro

wth

Rat

e (m

md

ay)

020

026

032

020

026

032

Razorback Growth in an Unlined Pond

Figure 8 Growth of razorbacksuckers (mmday plusmn standard error) in Pond 1 lower (an unlined pond)in 2010-shy‐2011 An ANOVA did notdetect any significant differences

6 Months 12 Months lt 300 mm Fish 300+ mm Fish Growth Growth

Lined vs Earthen Ponds 1 year of growth

Figure 9 Growth of razorbacksuckers (mmday plusmn standard error) in lined and unlined ponds A t-shy‐test13 did not detect a significantdifference

Lined Pond Unlined Pond 1 Yr Growth 1 Yr Growth

45

13

Effect of Sorting G

row

th R

ate

(mm

day

) G

row

th R

ate

(mm

day

)

032

020

026

032

020

026

Smaller Fish Larger Fish

Effect of Ich

Figure 10 Average growthof razorback suckers(mmday plusmn standard error)that were size-shy‐sorted intosmall fish (pond 7) and largefish (pond 8) populations At-shy‐test did not detect asignificant difference

Figure 11 Average growth ofrazorback suckers (mmday plusmnstandard error) after Ich wasremovd from the hatcheryrsquos springand after Ich was again detected inthe pond The growth rate withoutIch is significantly higher than boththe rate after Ich and the ourstudyrsquos average annual growth ratein lined ponds (ANOVA p =00003)

Growth without Ich Growth With Ich Average Annual 4 months 4 months Growth Rate

46

13

Effect of Ich on razorback sucker growth rates

Seventy-shy‐four13 tagged13 razorback suckers13 were13 recovered from13 Pond 8 on September

15 2010 These fish had13 been13 in the pond for 4 months and experienced a growth rate of

032 mmday or 97 mmmonth (Figure13 11)13 This growth13 rate13 is significantly higher (p =

005 two sample t-shy‐test) than the mean growth rate for the same group13 of tagged fish after

Ich detection (022 mmday or 65 mmmonth) and significantly higher than any other

individual growth13 rates13 observed13 to13 date13 at Bubbling13 Ponds Hatchery13 (Figure13 11)13 If this13

growth13 rate13 were13 extended throughout13 the entire13 year13 fish on average from13 Ich-shy‐free13 ponds13

would be 16 mm longer than fish from13 ponds infested with Ich Studies conducted at

Bubbling Ponds hatchery in 2008 (Ward 2008) did not reveal any effects of the treatment

chemicals on razorback sucker growth rates so it13 is likely that13 the parasite outbreaks

themselves are causing reducing growth rates rather than the chemicals used to treat the

parasites13

Conclusions

Our results suggest that under typical hatchery operations (maximizing number of

fish produced)13 the growth13 rate13 of razorback13 suckers13 is relatively13 consistent at Bubbling13

Ponds hatchery13 at 02-shy‐03 mmday (6-shy‐9 mmmonth)13 but is lower than growth13 rates13 at

other13 facilities (02 ndash 18 mmday Ward et al 2007)13 This growth13 rate13 has13 been13 constant in

both lined and unlined ponds and at all fish densities we were able to measure To achieve13

growth13 rates13 substantially higher than this will likely require13 significant changes in rearing

practices that may not be practical in order to reach numerical production13 goals

Temperature is a key variable in fish growth but seasonal growth patterns

described13 above13 (Figure13 5) demonstrate that water temperatures are high enough in

winter to maintain razorback growth Differences in water temperature by season

currently13 do not fluctuate more than 10degC at Bubbling Ponds because of the continuous

supply of water flowing through each pond (approx 225 gallonsmin) These high water

flows appear to keep pond temperatures within the thermal preference13 for razorback

suckers13 (1213 -shy‐ 28 degC Bulkley and Pimentel 1983) throughout the entire year with

temperatures rarely dropping13 below 16deg13 C (Figures 513 6)13

47

13

Fish density is another key variable in fish growth and though the number of fish in

a pond during our study ranged from13 3000 to 700013 fish we13 did not find any13 correlation13

between13 density and growth rate13 This might yield two conclusions First13 razorback

growth13 may be changed equally13 by13 densities13 at the13 hatchery13 (ie13 a density13 of 3000 fish in a

pond is as stressful13 for razorbacks as a density13 of 7000 fish) An alternative is that other

factors13 such as disease outbreaks have13 stronger13 control over fish growth13 than13 density13

Fish density13 would13 have13 to13 be13 experimentally manipulated to test13 this13 and hatchery

operations (producing the maximum13 number of fish) prevented our manipulating density13

in ponds for this13 work The trouble with manipulating density demonstrates the difficulties

associated with changing13 hatchery13 practices experimenting with density would have

prevented BPH from13 meeting13 production13 goals Given that the stocking of smaller

razorbacks has met with very little success perhaps BPH goals could be changed from13

producing 12000 fish at 300+ mm per year to a smaller number of very large fish each

year Growing13 fewer13 larger13 fish could potentially be accomplished in the same time frame

as more smaller fish but a better understanding of how density alters growth rate would

be required to be confident13 of this

The very slow growth13 in the13 earthen13 unlined13 Pond 1 lower13 was very surprising We13

had13 anticipated13 that the13 diversified diet13 cover and13 other13 habitat features13 provided by13

unlined ponds would yield dramatically increased growth rates However these traits were

not enough to offset high fish densities and in fact the unlined pond in our study13 suffered

mortality to bring densities down to that observed normally in lined ponds

Our data13 suggest13 that razorbacks13 sucker13 growth13 rates13 are13 higher in lined13 ponds13

However we13 think the reasons13 for the13 very slow growth we observed13 in the13 unlined13 pond13

in our study13 is instead13 linked13 to13 the13 usage13 of Pond 1 lower13 during13 the13 study13 rather13 than13

intrinsic13 slow growth13 in earthen13 ponds First the pond was at extremely high density for at

least part of the study The volume of Pond 1 lower has not been estimated but hatchery

managers suggest 1500-shy‐2000 fish is an appropriate number of individuals so this pond

was at a very high density for much of the experiment Second dissolved oxygen is often

very low in the13 large13 earthen13 ponds during the heat of summer much lower than that of

lined ponds This will both limit the number of fish that can survive in the pond and almost

certainly13 increases stress13 of these13 fish potentially13 reducing growth13 The DO crashes also13

48

13

limit the amount of feed hatchery managers can give fish in these ponds sometimes for

days or weeks at a time which further reduces growth during warm13 weather

Our data13 suggests that13 growth rates at the Bubbling13 Ponds Fish Hatchery are likely

as high as possible given13 the pond densities required to meet production goals and the Ich-shy‐

infested water that feeds the facility Sorting practices are successful in helping as many

fish as possible reach stocking length as fast as possible Unlined ponds may be able to

grow13 large13 fish at low13 densities13 but whatever factors allow13 for that13 growth are not13 able to

overcome high fish density The removal of invasive13 fis that act as13 a host for the13 parasite13

Ich fish from13 the Bubbling13 Ponds spring13 allowed the highest13 growth rate at 032 mmday13

(96 mmmonth) but that growth rate decreased again as Ich re-shy‐infested13 the13 hatchery13

Consistently13 achieving13 growth13 rates13 as high or substantially13 higher than13 this13 will likely13

require13 significant changes in rearing practices that may not be practical in order to13 reach13

numerical production13 goals

Two major changes that might result in higher growth rates are substantially

reducing fish density and modifying the way spring water is delivered to the facility (via

either repeated chemical treatments or enclosed concrete water diversions) to eliminate

Ich from13 the hatchery source water Other potential changes not address by our work

include13 flow-shy‐training razorbacks much previous literature including MSCP-shy‐funded13 work

on razorback suckers13 suggests13 that fish growing13 in flowing water will grow13 faster than fish

in still water (Jorgensen and Jobling 1994) Furthermore there are a wide variety of

potential benefits associated with growing13 fish13 in flowing13 water in addition13 to increased

growth13 rates13 (Davidson13 199713 Castro13 et al13 2011) Another option13 for increasing13 growth13

rates13 include13 changing to13 intensive13 culture13 in large circular13 tanks

Finally given that the stocking of smaller razorbacks has met with very little

success13 perhaps13 BPH13 goals13 could13 be13 changed from13 producing 12000 fish at 300+ mm per

year to a smaller number of very large fish each year Growing fewer larger fish could

potentially be accomplished in the same time frame as more smaller fish but a better

understanding13 of how density13 alters growth13 rate13 would13 be13 required to13 be13 confident of this

49

13

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower13 Colorado13 River Multi-shy‐Species13

Conservation Program13 (LCRMSCP) under Work Task C10 We13 thank Ty Wolters13 Tom13

Burke13 and Eric13 Volkman for their support of this research and Frank Agygos and Dave

Billingsly13 of the Bubbling13 Ponds Fish Hatchery13 for their willingness to participate in13 this

research13 and13 for their technical assistance We also thank the LCRMSCP fish group from13

Boulder City13 NV for their assistance with harvesting13 ponds and tagging13 fish13

50

13

Literature13 CitedAnders P J 1998 Conservation aquaculture and endangered species can objective science13

prevail13 over risk13 anxiety Fisheries 23(11) 28-shy‐31

Anderson R O and R M Nuemann 1996 Length weight and associated structural indicesPages 447 ndash 482 in B R Murphy13 and D13 W Willis13 editors13 Fisheries techniques13 2ndedtion American Fisheries13 Society13 Bethesda13 Maryland

Bain M B J T Finn and H E Brooks 1988 Streamflow regulation and fish communitystructure13 Ecology13 69382-shy‐392

Bays J H Zarbock R Whitman and T Murphy 2005 Conceptual design and managementof native13 fish refugia on the13 lower13 Colorado13 River In13 CL Spring13 and13 S Leoneditors Proceedings of two symposia Restoring native fish to the lower ColoradoRiver13 interactions13 of native and non-shy‐native13 fishes 13ndash1413 July13 1999 Las13 Vegas13 Nevada13 Restoring13 natural function within a modified riverine environment thelower Colorado River13 8ndash913 July13 1998 U S Fish and13 Wildlife13 Service Southwestern13 Region Albuquerque New Mexico Pages 167-shy‐177

Bertalanffy L Von 1957 Quantitative laws in metabolism13 and growth13 Q Rev Biology 32217 ndash 231

Bingham T B Scheer and C McAda 2003 Propagation facilities in Grand Valley (24 RoadHatchery Horsethief13 Ponds and13 grow-shy‐out ponds) for captive13 rearing13 ofendangered13 fishes for the13 upper13 Colorado13 River basin13 Colorado River RecoveryProgram FY2003 annual project report13 US Fish and13 Wildlife13 Service GrandJunction13 4pp

Birchell G J and K Christopherson 2004 Survival growth and recruitment of larval andjuvenile razorback13 sucker (Xyrauchen texanus) introduced13 into13 floodplain13 depressions13 of the13 Green River Utah13 Final report13 Upper13 Colorado13 RiverEndangered Fish Recovery Program13 Project No C-shy‐6RZ Publication Number 04-shy‐1513 Utah13 Division of Wildlife13 Resources Salt Lake13 City13 Utah13 67 pages

Brannon E L 1993 The perpetual oversight of hatchery programs Fishery Research 1819-shy‐27

Brett J R 1979 Environmental Factors and growth pages 599-shy‐67513 InW S Hoar13 D13 J13 Randall and J R Brett (eds) Fish Physiology Volume 8 Bioenergetics and GrowthAcademic Press New York

Brooks J E 1986 Annual reintroduction and monitoring report for razorback suckerXyrauchen texanus in the Gila River Basin Arizona 1985 US Fish and WildlifeService13 Offices of Endangered13 Species and Fishery13 Resources Albuquerque 23 pp

51

13

Brunson13 R E and K D13 Christopherson13 200513 Larval13 razorback13 sucker and bonytailsurvival and13 growth13 in the13 presence13 of nonnative13 fish in the13 Baeser13 floodplainwetland of the middle Green River Final report prepared for Upper13 Colorado RiverBasin Endangered Fish Recovery Program Project No C-shy‐6-shy‐rz-shy‐bt Publication13 No 05-shy‐26 Utah13 Division of Wildlife13 Resources13 Vernal13 32 pp

Bulkley R V and R Pimentel 1983 Temperature preference and avoidance by adultrazorback suckers Transactions of the American Fisheries Society 112601-shy‐607

Burke13 T13 199513 Rearing13 wild razorback13 sucker larvae in13 lake-shy‐side13 backwaters13 LakeMohave ArizonaNevada Proceedings of the Desert Fishes Council 2635

Busacker G P I R Adelman and E M Goolish13 199013 Growth13 Pages 363 ndash 387 in C BSchreck and p B Moyle editors Methods for fish biology American FisheriesSociety Bethesda Maryland

Castro V B Grisdale-shy‐Helland S J Helland T Kristensen S M Jorgensen J Helgrud13 GClaireaux A P Farrell A Krasnov and H Takle 2011 Aerobic training stimulatesgrowth and promotes disease resistance in Atlantic salmon (Salmo salar)Comparative Biochemistry and Physiology -shy‐ Part A Molecular amp IntegrativePhysiology13 160(2) 278-shy‐290

Czapla T E 2002 Facilities plan for the production of endangered fishes to meet statestocking13 plans13 as13 part of the13 Upper13 Colorado13 River Endangered13 Fish RecoveryProgram Upper Colorado River Basin Recovery Implementation Program US Fishand Wildlife Service13 Denver13 9 pp

Davidson W 1997 The effects13 of exercise13 training on teleost fish a review of recentliterature Comput Biochem Physiol 117A67ndash75

Figiel Jr C R 2005 Annual report fiscal year 2004 Willow Beach National13 Fish HatcheryUS Fish and Wildlife13 Service Willow Beach 17 pp

Figiel Jr C R M E Ulibarri G Carmichael J Seals and J N Hanson 2005 Intensive13 fish13 culture of warmwater native fishes at a coldwater fish hatchery Pages 164-shy‐16613 inProceedings of two symposia restoring native fish to the lower Colorado13 River13 interaction13 of native13 and13 non-shy‐native13 fishes July13 13-shy‐1413 1999 Las Vegas Nevada USFish and Wildlife Service Southwest Region Albuquerque New Mexico

Gerking13 S D 1978 Ecology of freshwater fish13 production13 Halstead Press13 New13 York

Gustafson W and Q Bradwisch 2000 Wahweap operation and maintenance -shy‐-shy‐ UtahColorado River Recovery Program FY 2000 annual project report Project No 29cUtah13 Division of Wildlife13 Resources Page AZ 3pp

52

13

Hamman R L 1985 Induced spawning of hatchery-shy‐reared13 razorback sucker ProgressivFish Culturist 47(3) 187-shy‐189

Hanson J N 1996 Annual report fiscal year 1996 Willow Beach National Fish HatcheryUS Fish and Wildlife Service13 Willow Beach 9pp

Irving D S Seversen and M Montagne 2004 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2004 annual project13 report Report No 29b US Fish and13 Wildlife13 Service Vernal 3pp

Jorgensen E H and13 M Jobling 1994 Feeding and13 growth13 of exercised13 and13 unexercised13 juvenile Atlantic salmon in freshwater and performance after transfer to seawaterAquaculture International 2 154-shy‐164

Kaeding L R and D B Osmundson 198913 Colorado13 Squawfish13 and13 razorback sucker grow-shy‐out pond studies as part of conservation measures for the green mountain andRuedi reservoir water sales Final report for agreement number 6-shy‐AA-shy‐60-shy‐00150

Koebele13 B P13 198513 Growth and the size hierarchy effect an experimental assessment ofthree proposed mechanisms activity differences disproportional food acquisition13 pysiological stress Environmental Biology of Fishes 12 181-shy‐188

Kretschmann A E and L L Leslie 2006 Razorback sucker (Xyrauchen texanus) status13 reproduction and recruitment in Senator Wash Reservoir CA Final Report13 to USBurea of Reclamation Cooperative Agreement No 00-shy‐FG-shy‐34-shy‐ 0009 p 32 ArizonaGame and Fish Department Phoenix

Marsh13 P13 C13 1987a13 Digestive tract13 contents13 of adult razorback suckers13 in Lake13 MohaveArizona-shy‐Nevada Transactions of the American Fisheries Society 116117-shy‐119

Marsh P C 1987b Native fishes at Buenos Aires National Wildlife Refuge and ArizonaState University Research Park Arizona opportunities for management researchand public13 education13 on13 endangered species13 Proceedings of the Desert13 FishesCouncil 1967-shy‐78

Marsh P C 1994 Rearing native Colorado River fishes in golf course ponds Arizona StateUniversity Tempe 22 + pages

Marsh13 P13 C13 200013 Fish population13 status and evaluation13 in13 the Cibola13 High Levee PondFinal report agreement number 99-shy‐FG-shy‐30-shy‐00051 US Bureau of ReclamationBoulder City13 Nevada13 20 pages

Marsh P C and C A Pacey 1998 Growth of wild adult razorback suckers13 in Lake13 Mohave13 Arizona-shy‐Nevada13 Final report13 US Bureau of Reclamation Boulder City Nevada 25pages + appendices

53

13

Marsh P C B R Kesner and C A Pacey 2005 Repatriation as s management strategy13 to13 conserve a critically13 imperiled fish species North American Journal of FisheriesManagement 25 547-shy‐556

Marsh P C and C A Pacey 2005 Immiscibility of native and non-shy‐native13 fishes Pages 59-shy‐63 inMJ13 Brouder13 CL13 Springer13 and CS13 Leon13 editors13 Proceedings of two13 symposia Restoring native fish to the lower Colorado River interactions of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 NV and13 Restoring natural13 function within a modified riverine environment the lower Colorado River13 July13 8-shy‐913 1998 Las Vegas NV US Fish and13 Wildlife13 Service Southwest Region AlbuquerqueNew Mexico

Marsh13 P13 C13 and J13 E Brooks13 198913 Predation13 by ictalurid catfishes as a deterrent13 toreestablishment of hatchery-shy‐reared13 razorback sucker The Southwestern Naturalist34188-shy‐195

Matthews R A 2005 Ichthyopthirus multifiliis Fouquet and Ichthyopthirosis infreshwater13 teleosts13 Pages13 159-shy‐218 in Advances in Parasitology volume 59 J RBaker R Muller D Rollinson (eds) Academic Press

McCarthy13 M S and W L Minckley 1987 Age estimation for razorback sucker (PiscesCatostomidae) from13 Lake Mohave Arizona and Nevada Journal of the Arizona-shy‐Nevada Academy of Science 2187-shy‐97

Minckley13 W L13 198313 Status of the razorback13 sucker13 Xyrauchen texanus (Abbot)13 in13 thelower Colorado River basin13 The Southwestern13 Naturalist13 28(2) 165-shy‐187

Minckley13 W L13 199113 Native fished of the Grand Canyon13 region an obituary13 Pages 124-shy‐177 in Colorado River ecology and dam13 management National Academy PressWashington13 DC

Minckley13 C13 O and M LaBarbara13 199913 Report13 on13 native fish grow-shy‐out facilities13 at Cibolaand Imperial National Wildlife Refuges 1993-shy‐199513 US Fish and13 Wildlife Service13 Parker Fishery Resources Office Parker Arizona

Modde13 T13 199613 Juvenile razorback sucker (Xyrauchen texanus) in a managed wetlandadjacent13 to the Green13 River13 Great13 Basin13 Naturalist13 56375-shy‐376

Modde T KP Burnham and E J Wick 1996 Population status of the razorback sucker13 inthe middle Green River (USA) Conservation13 biology 10 110-shy‐119

Modde13 T13 and G13 B Haines13 200513 Survival13 and growth of stocked razorback13 sucker andbonytail in multiple floodplain wetlands of the middle Green River under resetconditions13 Final report prepared for Upper Colorado13 River13 Basin RecoveryImplimentation Program US Fish and Wildlife Service Vernal 66 pp

54

13

Modde T Z H Bowen and D C Kitcheyan 2005 Spatial and temporal use of a spawning13 site in the middle Green River by wild hatchery-shy‐reared13 razorback suckers13 Transactions of the American Fisheries Society 134937-shy‐944

Mueller13 G13 199213 The native fish work13 group13 -shy‐ a multiagency endeavor to improve thestatus of the razorback sucker in Lake Mohave AZ-shy‐NV13 Proceedings of the DesertFishes Council 2369

Mueller G 1995 A program13 for maintaining the razorback sucker in Lake MohaveAmerican Fisheries Society Symposium 15127-shy‐135

Mueller13 G13 200613 Ecology of the bonytail13 and razorback13 sucker and the role of offchannelhabitats13 in their13 recovery Scientific13 investigations13 report 2006-shy‐5065 US GeologicalSurvey13 Denver

Mueller G and E Wick 1998 Testing of golf course ponds at Page Arizona for suitability13 as grow-shy‐out facility for razorback sucker using surplus fish from13 Ouray NationalFish Hatchery National Park Service US Fish and13 Wildlife13 Service and UtahDivision of Wildlife13 Resources 28 pages

Mueller13 G13 and T13 Burke13 200513 Survival13 of young13 razorback13 sucker (Xyrauchen texanus) inrelation to13 stocking rates13 (fishha)13 and13 in the presence13 or absence13 of predatorcommunities in Lake Mohave Arizona-shy‐Nevada13 Pages13 155-shy‐16313 in Proceedings of two13 symposia restoring native fish to the lower Colorado River interaction13 of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 Nevada US Fish and Wildlife13 Service Southwest Region Albuquerque New Mexico

Mueller13 G13 J13 Carpenter13 and P13 C13 Marsh13 200413 Cibola13 High Levee Pond annual report 2004US Geological Survey Fort Collins13 Science Center13 Colorado13 and Arizona StateUniversity Tempe 23 pages

Nesler T P K Christopherson J M Hudson C W McAda F Pfeifer and T E Czapla 2003An integrated stocking plan for razorback sucker bonytail and Colorado13 pikeminnow for the Upper Colorado River Endangered Fish Recovery ProgramAddendum13 to State Stocking Plans Upper Colorado River Basin Recovery13 Implementation Program 12 pp

Papoulias13 D and W13 L Minckley13 1992 Effects13 of foo availability13 on survival and growth13 of larval razorback suckers13 in ponds Transactions of the American Fisheries Society121340-shy‐355

Paukert13 C P D L Ward13 P J Sponholtz13 and K13 D Hilwig13 Effects13 of repeated hoopnetting13 on bonytail chub13 Journal of Freshwater13 Ecology13 20(4) 649-shy‐653

Pfeifer F M13 C Baker13 and M13 Montagne13 199913 Propagation13 facilities13 in the13 Grand Valley13 (24 Road13 Hatchery13 Horsethief13 Ponds and13 grow-shy‐out ponds) for captive rearing of

55

13

endangered13 fishes for the13 Upper Colorado13 River Basin13 Colorado13 River Recovery13 Program FY 99 annual project report Project No 29a13 US Fish and Wildlife Service13 Grand13 Junction13 5pp

Pfeifer F S Seversen and M Montagne 2003 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2003 annual reportProject No 29b13 US Fish and Wildlife13 Service Vernal13 4pp

Rabago-shy‐Castro J L Sanchez13 J G Perez-shy‐Castaneda R and13 Gonzalez-shy‐Gonzlez A 2006Effects of the prophylactic use of Romet-shy‐3013 and13 copper13 sulfate13 on growth13 condition13 and feeding13 indicies in13 channel13 catfish (Ictalurus punctatus) Aquaculture 253 343-shy‐349

Reinitz GL L E Orme and F N Hitzel 1979 Variations of body compositio and growth13 among strains of rainbow trout Transactions of the American Fisheries Society 108204-shy‐207

Ruppert13 J13 B P B Holden13 and P D Abate 1999 Age estimation and growth of razorbacksucker13 Xyrauchen texanus in Lake13 Mead Nevada Proceedings13 of the Desert FishesCouncil 3040

Schnoor K D and J Logan 2002 Operation and maintenance of JW Mumma nativeaquatic13 species restoration facility Colorado Colorado River Recovery Program FY2002 annual project report13 Project No 29d Colorado13 Division of Wildlife Alamosa3pp

Salisbury13 L13 1998 Factors13 affecting razorback13 sucker growth13 in Lake13 Mohave backwaters13 MS Thesis13 Unviersity13 of Nevada13 Las13 Vegas

Schooley J13 D13 and P C13 Marsh13 2007 Stocking of endangerdd13 razorback13 suckers13 in thelower Colorado River Basin13 over three decades 1974-shy‐2004 North American Journalof Fisheries Management 27 43-shy‐51

Severson S H H M Tyus and G B Haines 1992 An evaluation of feeds for raisingrazorback sucker Xyrauchen texanus Journal of Applied Aquaculture 155-shy‐65

Toney D P 1974 Observations13 on the13 propagation13 and13 rearing13 of two13 endangered species13 in a hatchery environment Proceedings of the Annual Conference of the Western13 Association of State Game and Fish Commissions 54 252-shy‐259

Tyus H M13 1998 Razorback sucker13 (Xyrauchen texanus) recovery plan13 University13 ofColorado Center for Limnology Boulder13 76 pages

Tyus H M13 and13 S H Severson 1990 Growth13 and13 survival of larval razorback suckers fedfive formulated diets The Progressive Fish Culturist 52197-shy‐200

56

13

Ulibarri M E 2003 Annual report fiscal year 2001 Dexter National Fish Hatchery13 andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 26 pages

Ulibarri M E 2003 Annual report fiscal year 2002 Dexter National Fish Hatchery andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 59 pages

USBR 2006 Lower13 Colorado13 River Multi-shy‐Species Conservation Program final fishaugmentation plan Boulder City 19 pp

USFWS 2002 Razorback sucker (Xyraouchen texanus) recovery goals Amendment andsupplement to the Razorback Sucker Recovery Plan13 US Fish and Wildlife Service13 Region 6 Denver13 Colorado

USFWS 1999 Annual report 1999 Ouray National Fish Hatchery Vernal 25pp

USFWS 2004 Management plan for the big-shy‐river13 fishes of the13 lower13 Colorado13 river basinamendment and supplement to the bonytail humpback chub Coloradopikeminnow and razorback sucker recovery plans

USFWS13 2005 Station13 profile13 of the13 Dexter13 National Fish Hatchery13 and Technology CenterUS Fish and Wildlife13 Service Dexter

Valdez R A P G Mangan R Smith and B Nilson 1982 Upper Colorado River fisheriesinvestigations13 inW H Miller J J Valentine D L Archer H M Tyus R A Valdezand L13 Kaeding13 editors13 Colorado River Fishery13 Project13 Part 2 Field13 investigations13 US Bureau of Reclamation Salt Lake City Utah

WBNFH 2004 Culture methods of the endangered razorback sucker Xyrauchen texanusUS Fish and Wildlife13 Service Willow Beach National Fish Hatchery13 8 pp

Ward D 2008 Effects of disease treatments on growth of razorback sucker ReportSubmitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 Inpartial fulfillment of work task C10 agreement number 06FG30039

Ward13 D13 M Childs and W Persons 2007 Factors13 affecting13 growth13 of razorback sucker13 (Xyrauchen texanus) in captivity Literature review and knowledge assessmentReport Submitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 In partial fulfillment of work task C10 agreement number 06FG30039

57

Appendices

Appendix 1 Survey Questions Survey of Razorback Sucker Culture in the

Southwestern United States

The enclosed survey is being distributed by the Arizona Game and Fish Department to razorback sucker culture facilities throughout

the Southwestern United States The purpose of this survey is to consolidate information regarding culture of this species so that

appropriate facility improvements can be considered for Bubbling Ponds Hatchery in Arizona Specifically we wish to increase

growth rate and production efficiency at the hatchery Information gathered in this survey will be summarized in a final report to US

Bureau of Reclamation in Boulder City NV and disseminated to all facilities that participate in the survey A workshop to discuss

the findings of this study as well as to share general information concerning razorback sucker culture will be organized by the

Arizona Game and Fish Department at the conclusion of this study and all participants will be invited

Thank you for taking the time to fill out this survey Please contact Mike Childs if you have questions or would like to discuss the

survey

Mike Childs

mchildssedonanet

(928) 639-1346

(928) 634-1279

Facility_____________________________________ Date___________________

Contact Phone _____________________________

ContactPerson_______________________________

Contact Email _______________________________

1 Water quality ranges at this culture facility

Season

Spring (Mar-May) Summer (Jun-Aug) Fall (Sept-Nov) Winter (Dec-Feb)

Temperature (C)

PH

DO (mgL)

PO4 (mgL)

TDS (mgL)

Hardness (mgL)

CaCO3

Pathogens

37

13

Each treatment consisted of a series of doses applied on Wednesday Thursday and

Friday with a 90water change between each dose Biofilters were removed from13 all

tanks and held in a separate holding facility during treatments and then replaced on the

Monday following treatments after a 90water change This schedule allowed fish to be

exposed to chemical treatments for 5 consecutive days without water quality deteriorating

This 5-shy‐day chemical treatment was repeated every two weeks from13 July to October (97

days)13 for a total of 5 5-shy‐day treatments Water temperature in the treatment tanks ranged

from13 13degC (55degF) to 32degC (91degF)

Fish were fed a fixed ration of commercial razorback diet (Silvercup 4mm13 pellet)

once daily13 (2 percent body13 weight per day13 as calculated13 by13 average initial fish weight)13

At the end of the experiment all fish were again weighed measured and scanned for

individual tag numbers Growth of fish in each treatment group was compared using

analysis of variance (ANOVA) Any mortalities13 that occurred during the13 study13 were13

replaced with previously quarantined fish of equivalent size to maintain equal densities in

each13 tank13 but growth13 data was13 only13 recorded for fish which13 survived13 the13 entire13

experiment

Results

Fish at the13 start of the experiment averaged 179 mm TL (Range13 = 127 ndash 262 mm)

with no significant differences in fish length among treatment groups (F(4189) = 00183 p

gt 0999 ANOVA) On average fish grew 235 mm TL (024 mmday) during the 3 month

study13 Fish in tanks13 treated with formalin had the highest growth averaging 29 mm TL (03

mmday) while fish in tanks treated with copper had the lowest growth averaging 20 mm

TL (021 mmday) Fish in the control tanks averaged 213 mm TL in growth (022

mmday) (Figure13 3)13 Formalin-shy‐treated fish grew13 significantly faster than13 any other

treatment group but no13 significant differences in growth13 in length13 or weight were13

observed among fish treated with any of the chemicals compared to untreated (control)

fish (pgt005 ANOVA)

32

13

Figure 313 Average growthof razorback suckersexposed to a series of 5 5-shy‐day chemical treatmentsover a 97-shy‐day13 periodError bars representstandard error

Discussion13

Growth13 rates13 observed13 in our study13 (021 ndash 03 mmday) are low compared to those

reported13 in other13 studies13 of razorback sucker13 growth13 (0213 ndash 18 mmday) (Ward et al

2007) Using recirculating water systems for our study required filters to be removed and

replaced during treatments Stress to fish caused by removing and replacing filters within

the tanks as well as repeated water changes may have led to overall higher stress and

reduced growth rates compared to those reported for unconfined fish Growth in fish is

highly variable and is affected by many different physiological and environmental factors

including fish size density temperature amount of space and food (Brett 1979) We

strived to control each of these factors but other factors may have also influenced growth

in our experimental tanks During mid-shy‐summer water temperatures in the treatment

tanks reached 32degC (91degF) At these warm13 temperatures fish are very susceptible to

bacterial13 infections13 The slightly higher growth exhibited by fish in the formalin and

potassium13 permanganate treatments may have been the result of these two chemicals

33

13

being effective at controlling bacterial infections The differences in growth we measured

among treatment groups were not statistically significant and do not appear13 biologically13

meaningful during the relatively short duration of this study (97 days) although the

cumulative effects of slightly reduced growth could be biologically meaningful over longer

time frames

Reductions in growth13 as a result13 o repeated chemical treatments are not likely the

cause of differences in growth rates among facilities that raise razorback suckers

Repeated chemical treatments may have other impacts to overall fitness or long-shy‐term13

survival but these13 effects13 were13 not evident in our study It is more likely that the parasite

outbreaks themselves are the cause of different growth rates among razorback rearing

facilities rather than the chemical treatments used to treat the parasites We recommend

that hatchery managers continue to use the chemicals that are most effective at controlling

ldquoIchrdquo13 at their individual13 facilities

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower Colorado Rive Multi-shy‐species13

Conservation Plan under Work Task C10 We thank Ty Wolters and Tom13 Burke for their

support of this research and Frank Agygos and Dave Billingsly of the Bubbling Ponds Fish

Hatchery13 for their13 technical assistance13 and13 help with13 collecting13 fish

34

13

III13 Razorback Growth Rates at Bubbling Ponds ndash 2009-shy‐2011

Section13 SummaryExperimental studies at Bubbling Ponds Fish Hatchery AZ have strived to understand

factors that affect razorback sucker growth in captivity and identify ways to improve growthrates and maximize size at release Rather than performing experimental studies that wouldrequire major13 rearrangement (and likely reduced production)13 of hatchery operations our13 studies13 used normal variation in production techniques13 and practices13 to isolate factors13 thatmay modify growth rates

Our initial work identified razorback13 growth rates in13 lined ponds at standard fishdensity as 026 to13 028mmday (789 to 843 mmmonth) No significant differences in growthrate were observed among fish that had been in the pond only during the winter13 periodcompared to fish that had been in the pond the entire year indicating that water temperatures13 at Bubbling Ponds are high enough to allow fish to incorporate feed effectively year-shy‐roundHowever these growth rates are lower than most values reported from the literature fromnatural or semi-shy‐natural pond environments No significant differences in13 growth rate wereobserved13 between large and13 small fish13 within the 150 ndash 29 mm TL13 size range Additional worksuggests13 that razorback suckers13 tagged at over 300 mm TL had reduced growth rates (024mmday 73 mmmonth) as would be expected according to a typical Von13 Bertalanfy growthcurve although growth rates13 were only slightly less13 than the average growth rate for thehatchery (027513 mmday 82513 mmmonth)

Sorting13 to13 separate small fish from large fish after the first year of growth is practicedesigned13 to allow smaller fish to ldquocatch uprdquo to larger fish We found that13 this technique doesappear to13 improve growth rates of smaller fish Growth rates of sorted small razorback suckers(029 mmday 87mmmonth)13 were equal to that13 of larger13 fish (028 mmday 8413 mmmonth)indicating that sorting may have helped to offset their original slower growth trajectory

Bubbling Ponds Fish Hatchery grows razorbacks in 6 long deep ponds lined with heavyplastic 2 long deep13 earthen13 (unlined) ponds and three wide shallow earthen ponds The wideshallow ponds13 have historically produced very large fish at low density but have been found tomaintain much lower fish numbers than deeper ponds We found13 that growth13 rates ofrazorbacks kept at high density (4-shy‐700013 fish)13 in a wide shallow pond grew extremely slowly(024 mmday 726 mmmonth) This growth rate is among the slowest of any fish over theyears of our study and demonstrates that13 though the large ponds may produce large fish at lowdensity13 they are unable to overcome high13 fish13 densities

Finally one of the major factors influencing13 fish13 growth13 in hatcheries is disease onemajor summer-shy‐time disease at13 Bubbling Ponds is the ectoparasite Ich (Ichthiopthirusmultifiliis) To investigate the impact Ich has on razorback growth we eradicated fish from thespring and water conveyance ditch that supplies13 water to the hatchery using Rotenone This13 restoration effort was fairly short-shy‐lived (Ich returned to the hatchery within four months) but

35

13

growth13 rates of fish13 reared for four months without Ich present (031 mmday 92 mmmonth)were significantly higher than the following 8 months of growth for those same fish (022mmday 65 mmmonth) This disease-shy‐free growth rate is in fact faster than any13 otherprevious growth rates observed at the hatchery in our study

We conclude that growth rates at the Bubbling Ponds Fish Hatchery are likely as highas possible given the pond densities required to13 meet production goals and the Ich-shy‐infestedwater13 that feeds the facility Sorting practices are successful in helping as many fish as possiblereach stocking length as fast as possible Unlined ponds may be able to grow large fish at lowdensities but whatever factors allow for that growth13 are not able13 to overcome13 high fish densityThus the large lower ponds at Bubbling Ponds may be better utilized via renovation to13 deepenand line them

Disease is the most important factor limiting growth as may be expected to be the caseat many13 hatcheries While the spring renovation was not13 a complete success13 the dramaticreduction of fish populations in that habitat was enough to dramatically13 reduce13 the13 occurrenceof Ich at the hatchery13 Such open spring13 systems feeding a hatchery are a misfortune that canbe expected to transmit disease so we suggest that renovating the spring again to combat13 IchImproved techniques to divert water from13 the springs and more throuough treatment ofstream-shy‐side vegetation may improve the success of chemical treatment Successful renovationwould likely both improve growth rates and reduce chemical costs associated with treating Ichoutbreaks Even13 if complete renovation13 is impossible or impractical an13 effort to reduceinvasive fish density in the springs13 which act a vector for the parasite(and thereby reduce thelikelihood of13 Ich being transmitted into ponds) may still13 show dramatic improvements

36

13

Introduction

Conservation efforts13 for razorback sucker13 (Xyrauchen texanus)13 currently13 depend on

captive rearing and stocking programs Low survival of stocked razorback suckers (Brooks

1986 Marsh13 and13 Brooks13 1989 Marsh13 and13 Pacey13 2005) has13 caused13 target sizes for stocked13

fish to steadily increase in efforts to reduce predation mortality13 (Marsh13 et al13 2005

Schooley and Marsh 2007) Rearing fish to larger sizes at hatcheries comes with increased

costs and creates the need to evaluate husbandry and rearing practices that may affect fish

growth13 We evaluated growth13 rates13 of individual razorback suckers13 in ponds13 at Bubbling

Ponds Fish Hatchery13 using Passive Integrated13 Transponder (PIT) tags13 to13 obtain13 precise

growth information for individual fish so that valid comparisons of growth rates as related

to rearing practices can be made

Due to the critical nature of the razorback sucker stocking program we did not

design experimental studies that would require major rearrangement and potentially

reduce production of hatchery operations Instead our studies used normal variation in

production techniques and practices to isolate factors that may modify growth rates

Though this methodology dramatically limits replication and may limit our ability to

directly13 attribute13 differences in growth13 rates13 to13 the13 variables13 we13 investigate13 we13 were13 able13

to accomplish research goals without altering hatchery operations or impacting

production

From13 2009 through 2011 we conducted a series of observational13 growth13 studies to

determine growth rates of individual razorbacks at Bubbling Ponds The first set of

experiments included13 identifying13 growth13 rates13 in lined13 and13 unlined13 ponds determining

growth13 rates13 of fish at different13 sizes13 in13 relation13 to sorting13 practices and monitoring

razorback growth rates after removing the source of the ectoparasite13 Ich (Ichthiopthirus

multifiliis) from13 the hatchery water source13

Razorback growth rate in lined ponds

Our first growth study documented individual growth rates at normal density in 11

million gallon lined ponds13 over two13 years13 This is the standard13 grow-shy‐out process for

razorbacks13 at Bubbling Ponds We monitored growth of fish for a variety13 of sizes and13 the13

37

13

amount of time in a pond during the growing season These13 data give a snapshot of growth13

rates13 at the13 facility13 and13 provide13 the basis for comparisons throughout our study

Growth rate13 in an unlined pond

In addition13 to 6 ponds lined with heavy plastic13 sheeting13 Bubbling Ponds Fish13

Hatchery maintains two narrow and deep (same dimensions as lined ponds13 Figure13 4)13 and13

three large13 shallow unlined ponds These earthen13 ponds typically have vegetation and

associated aquatic invertebrates that may better simulate natural environments by

providing cover and improved food diversity or quality Therefore these unlined ponds

may be expected to produce higher growth rates and potentially improved survival that is

more similar to growth rates observed in more natural grow-shy‐out facilities13 Historically13 the13

large13 shallow13 ponds have produced very large fish when13 utilized at low13 fish density13 The

narrow13 deep earthen13 ponds are13 used to grow13 fry13 at high density in their first13 year of life

The major downside to unlined ponds is the difficulty in harvesting fish where a lined

pond might take 8-shy‐1013 people13 a half13 day13 to13 harvest13 lined13 ponds13 require13 intensive13 weeding13

to allow seines to be pulled and therefore require many more personnel-shy‐hours13 In addition13

to harvest challenges the shallow earthen ponds tend to suffer from13 dissolved oxygen

crashes during the summer Unlined ponds also may maintain higher13 populations13 of non-shy‐

target species such as bluegill sunfish mosquito fish and bullfrog tadpoles We measured

growth rates of suckers in a large shallow earthen pond for comparison to growth in lined

ponds13

Figure13 4 Lined13 and13 earthen ponds13 of similar dimensions (approx 1000000 gallons first

and second panels) and a large13 shallow13 earthen13 pond (third panel)

38

13

Effect of sorting on growth

Razorback13 suckers13 are13 currently13 sorted13 after their first13 year of growth13 They are13

typically removed from13 one of the13 upper earthen13 ponds and13 split into13 two13 lined13 ponds for

subsequent grow-shy‐out13 The larger13 fish (gt approximately 140 mm) are placed into one pond

and the smaller individuals in another It is possible that the larger fish were more

aggressive or adept13 at taking food so this sorting process is intended to allow smaller fish

to improve their growth rate

Effect of Ich on razorback sucker growth rates

We13 evaluated13 growth13 rates13 of razorback sucker13 in the13 presence13 and absence of the

ectoparasite13 Ich (Ichthiopthirus multifiliis) Ich outbreaks can occur in wild populations13 but

hatcheries13 have13 proven excellent locations13 for Ich because13 of very high fish densities13 which13

facilitate13 the13 transfer13 of Ich13 between13 fish This common fish parasite causes direct mortality13

to razorback13 suckers as well13 as secondary bacterial13 infections13

The open spring and13 ditch13 which13 provides water to the Bubbling13 Ponds Hatchery

has long13 been infested with mosquitofish (Gambusia affinis) that harbor13 the13 Ich parasite13

and allow13 it13 to enter the hatchery with incoming13 water13 The solution13 to13 the13 Ich problem13

was to remove the mosquitofish host using13 Rotenone Razorback13 sucker growth13 rates were13

then tracked in13 the absence of this parasite for 4 months and compared with growth rates

after Ich returned to the pond and from13 previous years

Methods

Razorback growth rate in lined ponds

On May 14 2008 141 razorback suckers were tagged with 12 mm PIT tags (1342

kHz) and placed in Pond 3 (approximately 1100000 gallons13 Figure13 4)13 at Bubbling13 Ponds

Fish Hatchery Fifty-shy‐three of these tags were recovered two months later when a large

Ichthyophthirius multifilis (Ich) outbreak killed many fish in the pond On October 15 2008

an additional13 145 PIT tagged13 fish were13 also placed into Pond13 3 On13 May13 14 2009 Pond13 3

was harvested and a total13 of 141 PIT tagged fish were recovered13 Of the tagged fish13 26 fish

had13 been13 in the13 pond since May13 of 2008 (378 days13 o growth) and 115 had been13 in13 the

39

13 40

pond since October13 15 2008 (211 days13 of growth) Numbers of fish in Pond 3 after the Ich

outbreak and for the majority of the period of growth were between 3 000 and 4000 fish

A Hobotempreg temperature13 logger13 was13 also13 installed13 in Pond 3 one meter below the water

surface13 near13 the13 outflow and13 recorded water temperature every 3 hours to allow analysis

of the effects of water temperature on growth rate (Figure13 5) This Hobotemp data is

representative of other pond temperatures throughout this study

In a second experiment 210 adult13 razorback suckers13 were13 PIT tagged13 on13 May 14

2009 and13 placed13 into13 Pond13 3 upper to13 evaluate13 growth13 rates13 of larger13 razorback suckers13 at

Bubbling13 Ponds Hatchery13 under current13 rearing13 conditions13 Size of these fish at tagging13

was (mean = 285 mm range = 205 ndash 396 mm) These fish remained in the pond for 257

days and were harvested on Jan 25 2010 to provide information on growth rates of larger

razorback suckers13 under13 current rearing conditions

Figure 513 Temperatures (degC) inrearing pond at BubblingPonds Hatchery from July toSept 2009 (top graph)13 andfrom Nov to Dec 2009 (Lowergraph) Temperaturesrecorded with a Hobotempregremote data logger13 every 3hours

13

Growth rate13 in an unlined pond

To document razorback sucker growth in earthen ponds we introduced13 225 tagged13

razorback suckers13 into13 Pond13 1 lower13 (Figure 4) in February 3 2010 Additional tagged fish

from13 other studies were added to the pond throughout the growing season and the density

of 1 lower reached a maximum13 of nearly 7000 fish in early summer 2010 Density was

reduced to approximately 6000 fish by capturing fish with hoop nets on June 3 2010 54 of

these fish were tagged fish and returned to 1 lower after being weighed and measured The

pond was harvested on January13 2713 2011 and a total13 of 254 tagged fish out13 of 4296 fish

total were removed from13 the pond The pond was harvested on January 27 2011 (358 days13

of growth) and the tagged fish were weighed and measured Total number of razorbacks in

the pond at harvest13 was 4296

Effect of sorting practices on growth rates

On March 1113 200913 Pond13 5 upper was13 harvested13 and13 split into13 two13 separate13 groups

Two hundred of the smaller fish (average size = 122 mm TL) were PIT tagged and placed

into13 Pond13 7 upper and13 200 of the13 larger13 fish (average = 160 mm TL) were PIT tagged and

placed int Pond13 8 upper Density13 in Pond13 7 was13 4500 fish and13 in Pond13 8 there13 were13 6500

fish These ponds were then harvested after 1 year and growth rates were compared to

give information on the effects of current sorting practices Hobotempreg temperature

loggers were installed in13 Ponds 7 and13 8 during13 the13 grow-shy‐out period with13 water13

temperature recorded every 2 hours13 (Figure13 6)

Effect of Ich on razorback sucker growth rates

Bubbling Ponds spring was treated with Rotenone (CFT Legumine 5) at a

concentration of 2 ppm13 to remove all mosquitofish from13 the spring The treatment

consisted of two treatments 6 hours in duration on two consecutive days (April 12 -shy‐ 13)

using13 drip13 stations13 and13 backpack sprayers13 followed13 by13 an13 additional 6 hours13 of

detoxification using sodium13 permanganate Although 12 mosquitofish were captured in the

spring pond the week following the treatments subsequent minnow trapping (20 traps

checked13 daily13 for 3 weeks) did not capture any additional fish until August 11 2010 when

41

13

juvenile mosquitofish were again detected in the spring pond Minnow traps have

subsequently been set daily with several hundred individuals removed To evaluate if Ich

was also again present in the spring we captured 15 mosquitofish from13 the spring pond on

three separate days and placed them13 in an aquaria at 25 degC with 5 longfin dace known to be

free of Ich These fish were monitored for 2 weeks with no signs of Ich developing This

indicates that even though mosquitofish have returned to the spring pond the parasite is no

longer present13 although how13 long13 this condition13 will13 persist13 is unknown13

On May 1113 201013 200 juvenile razorback13 suckers were harvested out13 of Pond 5

upper (2009 year Class from13 Dexter National Fish Hatchery) and were PIT tagged and

placed into Pond 8 to evaluate if growth rates at bubbling ponds hatchery have improved

following the renovation of the spring and the removal of the Ich parasite Unfortunately13

on Sept13 8 2010 Ich was13 again13 detected13 in Pond 8 and the pond was immediately seined

and 74 tagged fish were measured to obtain growth information for the 4-shy‐month period

during13 which13 the13 pond13 was13 Ich-shy‐free13

Figure13 6 Temperatures (degC) in rearingponds 7 and 8 at Bubbling Ponds Hatchery13 from March 2009 ndash March 201013 pond 7(top13 graph)13 and13 pond 8 (Lower13 graph)13 Temperatures recorded with a Hobotempregremote data logger every 3 hours

42

13

Results

Growth in Lined Ponds

Razorback suckers13 that had been13 in13 Pond 8 upper for the13 entire13 year13 grew an13

average of 0263 mmday (789 mmmonth) and razorback suckers that had been in the

pond for 7 months (Oct -shy‐ May) grew13 on13 average of 028 mmday (843 mmmonth) (Figure13

7) These growth13 rates13 did not significantly13 differ Fish density13 in Pond 3 during13 the13

majority of the growth period was13 00032 ndash 00036 fishgallon13 Additionally no13 significant

differences in growth rate were observed between fish smaller than 210 mm TL and fish

larger than 210 mm TL when all recaptured fish were combined

We also measured the growth rate of very large fish in a lined pond On Jan13 2513 201013

156 adult fish with PIT tags were recovered from13 Pond 3 upper13 These fish were13 in the13

pond for 257 days and experienced an average13 growth13 rate13 of 024mmday or 73

mmmonth (Figure13 7)13 This growth13 rate13 is slightly13 lower13 than13 the13 average13 growth13 rate13

observed13 at Bubbling13 Ponds Hatchery in other studies (0275 mmday 825 mmmonth)

but may not be biologically meaningful We would expect larger13 fish to13 have13 reduced

growth rates according to a typical Von Bertalanfy growth model (Bertalanffy 1957) but it

appears that13 over the size range we evaluated (300 -shy‐ 450 mm TL) growth rates have not

slowed significantly compared to that of smaller13 fish grown at Bubbling Ponds13 Hatchery

Growth13 of razorback suckers13 is known13 to13 slow as13 fish reach13 larger13 sizes but it appears13 this13

reduced growth rate may not really start to be biologically meaningful at Bubbling Ponds

Hatchery13 until razorback suckers13 exceed 450 mm TL

Growth in unlined ponds

Growth13 rates13 for the13 fish recaptured13 during13 the Pond 1 lower13 thinning13 (120 days13 in

the pond) was 024 plusmn 003 mmday (729 plusmn 090 mmmonth) (Figure13 8)13 Fish13 that were13 in

the pond for nearly the entire year grew13 an13 average13 of 024 plusmn 001 mmday (726 plusmn 027

mmmonth) These growth rates are surprisingly the lowest measured growth rates for

any part of our study and differ significantly from13 every other measured growth rate

except very large13 fish (Figure13 9)13 Separating13 out13 large fish that13 were in13 the pond for the

entire year makes no difference fish that were added to the pond at TL lt300 mm grew

43

13

Gro

wth

Rat

e (m

md

ay)

020

026

032

0244 plusmn 001 mmday (733 plusmn 028 mmmonth) and and those with TL gt= 300 mm at the

start of the experiment grew 022 plusmn 003 mmday (651 plusmn 101 mmmonth)

Razorback Growth Rates in Lined Ponds

Figure 7 Growth ofrazorback suckers in(mmday plusmn standard error)in Pond 8 upper in 2008-shy‐2009 An ANOVA did notdetect any significantdifferences

7 Months Full Year 300+ mm fish

Effects of sorting on growth

One hundred and seventy five tagged razorback suckers were recovered from13 Pond

8 upper13 on March13 24 2010 (378 days13 of growth)13 These were13 the13 larger sorted13 fish (gt140

mm TL) that came out of Pond13 5 on March13 11 2009 One13 hundred and13 twenty13 two13 tagged13

razorback suckers were also recovered from13 Pond13 7 upper on March13 31 2010 (385 days13 of

growth)13 These were13 the13 smaller sorted13 fish (lt140 mm TL) that came out of Pond13 5 on

March 1113 200913 No significant differences in growth rate (mmday) were observed among

larger fish in Pond 8 and smaller fish in Pond 7 (pgt005 ANOVA) (Figure 10)13 indicating

that13 sorting may have helped to offset the original slower growth trajectory of the smaller

fish Temperatures of Ponds 7 and 8 upper remained similar throughout the year13 (Figure

5)

44

13

13

13

Gro

wth

Rat

e (m

md

ay)

Gro

wth

Rat

e (m

md

ay)

020

026

032

020

026

032

Razorback Growth in an Unlined Pond

Figure 8 Growth of razorbacksuckers (mmday plusmn standard error) in Pond 1 lower (an unlined pond)in 2010-shy‐2011 An ANOVA did notdetect any significant differences

6 Months 12 Months lt 300 mm Fish 300+ mm Fish Growth Growth

Lined vs Earthen Ponds 1 year of growth

Figure 9 Growth of razorbacksuckers (mmday plusmn standard error) in lined and unlined ponds A t-shy‐test13 did not detect a significantdifference

Lined Pond Unlined Pond 1 Yr Growth 1 Yr Growth

45

13

Effect of Sorting G

row

th R

ate

(mm

day

) G

row

th R

ate

(mm

day

)

032

020

026

032

020

026

Smaller Fish Larger Fish

Effect of Ich

Figure 10 Average growthof razorback suckers(mmday plusmn standard error)that were size-shy‐sorted intosmall fish (pond 7) and largefish (pond 8) populations At-shy‐test did not detect asignificant difference

Figure 11 Average growth ofrazorback suckers (mmday plusmnstandard error) after Ich wasremovd from the hatcheryrsquos springand after Ich was again detected inthe pond The growth rate withoutIch is significantly higher than boththe rate after Ich and the ourstudyrsquos average annual growth ratein lined ponds (ANOVA p =00003)

Growth without Ich Growth With Ich Average Annual 4 months 4 months Growth Rate

46

13

Effect of Ich on razorback sucker growth rates

Seventy-shy‐four13 tagged13 razorback suckers13 were13 recovered from13 Pond 8 on September

15 2010 These fish had13 been13 in the pond for 4 months and experienced a growth rate of

032 mmday or 97 mmmonth (Figure13 11)13 This growth13 rate13 is significantly higher (p =

005 two sample t-shy‐test) than the mean growth rate for the same group13 of tagged fish after

Ich detection (022 mmday or 65 mmmonth) and significantly higher than any other

individual growth13 rates13 observed13 to13 date13 at Bubbling13 Ponds Hatchery13 (Figure13 11)13 If this13

growth13 rate13 were13 extended throughout13 the entire13 year13 fish on average from13 Ich-shy‐free13 ponds13

would be 16 mm longer than fish from13 ponds infested with Ich Studies conducted at

Bubbling Ponds hatchery in 2008 (Ward 2008) did not reveal any effects of the treatment

chemicals on razorback sucker growth rates so it13 is likely that13 the parasite outbreaks

themselves are causing reducing growth rates rather than the chemicals used to treat the

parasites13

Conclusions

Our results suggest that under typical hatchery operations (maximizing number of

fish produced)13 the growth13 rate13 of razorback13 suckers13 is relatively13 consistent at Bubbling13

Ponds hatchery13 at 02-shy‐03 mmday (6-shy‐9 mmmonth)13 but is lower than growth13 rates13 at

other13 facilities (02 ndash 18 mmday Ward et al 2007)13 This growth13 rate13 has13 been13 constant in

both lined and unlined ponds and at all fish densities we were able to measure To achieve13

growth13 rates13 substantially higher than this will likely require13 significant changes in rearing

practices that may not be practical in order to reach numerical production13 goals

Temperature is a key variable in fish growth but seasonal growth patterns

described13 above13 (Figure13 5) demonstrate that water temperatures are high enough in

winter to maintain razorback growth Differences in water temperature by season

currently13 do not fluctuate more than 10degC at Bubbling Ponds because of the continuous

supply of water flowing through each pond (approx 225 gallonsmin) These high water

flows appear to keep pond temperatures within the thermal preference13 for razorback

suckers13 (1213 -shy‐ 28 degC Bulkley and Pimentel 1983) throughout the entire year with

temperatures rarely dropping13 below 16deg13 C (Figures 513 6)13

47

13

Fish density is another key variable in fish growth and though the number of fish in

a pond during our study ranged from13 3000 to 700013 fish we13 did not find any13 correlation13

between13 density and growth rate13 This might yield two conclusions First13 razorback

growth13 may be changed equally13 by13 densities13 at the13 hatchery13 (ie13 a density13 of 3000 fish in a

pond is as stressful13 for razorbacks as a density13 of 7000 fish) An alternative is that other

factors13 such as disease outbreaks have13 stronger13 control over fish growth13 than13 density13

Fish density13 would13 have13 to13 be13 experimentally manipulated to test13 this13 and hatchery

operations (producing the maximum13 number of fish) prevented our manipulating density13

in ponds for this13 work The trouble with manipulating density demonstrates the difficulties

associated with changing13 hatchery13 practices experimenting with density would have

prevented BPH from13 meeting13 production13 goals Given that the stocking of smaller

razorbacks has met with very little success perhaps BPH goals could be changed from13

producing 12000 fish at 300+ mm per year to a smaller number of very large fish each

year Growing13 fewer13 larger13 fish could potentially be accomplished in the same time frame

as more smaller fish but a better understanding of how density alters growth rate would

be required to be confident13 of this

The very slow growth13 in the13 earthen13 unlined13 Pond 1 lower13 was very surprising We13

had13 anticipated13 that the13 diversified diet13 cover and13 other13 habitat features13 provided by13

unlined ponds would yield dramatically increased growth rates However these traits were

not enough to offset high fish densities and in fact the unlined pond in our study13 suffered

mortality to bring densities down to that observed normally in lined ponds

Our data13 suggest13 that razorbacks13 sucker13 growth13 rates13 are13 higher in lined13 ponds13

However we13 think the reasons13 for the13 very slow growth we observed13 in the13 unlined13 pond13

in our study13 is instead13 linked13 to13 the13 usage13 of Pond 1 lower13 during13 the13 study13 rather13 than13

intrinsic13 slow growth13 in earthen13 ponds First the pond was at extremely high density for at

least part of the study The volume of Pond 1 lower has not been estimated but hatchery

managers suggest 1500-shy‐2000 fish is an appropriate number of individuals so this pond

was at a very high density for much of the experiment Second dissolved oxygen is often

very low in the13 large13 earthen13 ponds during the heat of summer much lower than that of

lined ponds This will both limit the number of fish that can survive in the pond and almost

certainly13 increases stress13 of these13 fish potentially13 reducing growth13 The DO crashes also13

48

13

limit the amount of feed hatchery managers can give fish in these ponds sometimes for

days or weeks at a time which further reduces growth during warm13 weather

Our data13 suggests that13 growth rates at the Bubbling13 Ponds Fish Hatchery are likely

as high as possible given13 the pond densities required to meet production goals and the Ich-shy‐

infested water that feeds the facility Sorting practices are successful in helping as many

fish as possible reach stocking length as fast as possible Unlined ponds may be able to

grow13 large13 fish at low13 densities13 but whatever factors allow13 for that13 growth are not13 able to

overcome high fish density The removal of invasive13 fis that act as13 a host for the13 parasite13

Ich fish from13 the Bubbling13 Ponds spring13 allowed the highest13 growth rate at 032 mmday13

(96 mmmonth) but that growth rate decreased again as Ich re-shy‐infested13 the13 hatchery13

Consistently13 achieving13 growth13 rates13 as high or substantially13 higher than13 this13 will likely13

require13 significant changes in rearing practices that may not be practical in order to13 reach13

numerical production13 goals

Two major changes that might result in higher growth rates are substantially

reducing fish density and modifying the way spring water is delivered to the facility (via

either repeated chemical treatments or enclosed concrete water diversions) to eliminate

Ich from13 the hatchery source water Other potential changes not address by our work

include13 flow-shy‐training razorbacks much previous literature including MSCP-shy‐funded13 work

on razorback suckers13 suggests13 that fish growing13 in flowing water will grow13 faster than fish

in still water (Jorgensen and Jobling 1994) Furthermore there are a wide variety of

potential benefits associated with growing13 fish13 in flowing13 water in addition13 to increased

growth13 rates13 (Davidson13 199713 Castro13 et al13 2011) Another option13 for increasing13 growth13

rates13 include13 changing to13 intensive13 culture13 in large circular13 tanks

Finally given that the stocking of smaller razorbacks has met with very little

success13 perhaps13 BPH13 goals13 could13 be13 changed from13 producing 12000 fish at 300+ mm per

year to a smaller number of very large fish each year Growing fewer larger fish could

potentially be accomplished in the same time frame as more smaller fish but a better

understanding13 of how density13 alters growth13 rate13 would13 be13 required to13 be13 confident of this

49

13

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower13 Colorado13 River Multi-shy‐Species13

Conservation Program13 (LCRMSCP) under Work Task C10 We13 thank Ty Wolters13 Tom13

Burke13 and Eric13 Volkman for their support of this research and Frank Agygos and Dave

Billingsly13 of the Bubbling13 Ponds Fish Hatchery13 for their willingness to participate in13 this

research13 and13 for their technical assistance We also thank the LCRMSCP fish group from13

Boulder City13 NV for their assistance with harvesting13 ponds and tagging13 fish13

50

13

Literature13 CitedAnders P J 1998 Conservation aquaculture and endangered species can objective science13

prevail13 over risk13 anxiety Fisheries 23(11) 28-shy‐31

Anderson R O and R M Nuemann 1996 Length weight and associated structural indicesPages 447 ndash 482 in B R Murphy13 and D13 W Willis13 editors13 Fisheries techniques13 2ndedtion American Fisheries13 Society13 Bethesda13 Maryland

Bain M B J T Finn and H E Brooks 1988 Streamflow regulation and fish communitystructure13 Ecology13 69382-shy‐392

Bays J H Zarbock R Whitman and T Murphy 2005 Conceptual design and managementof native13 fish refugia on the13 lower13 Colorado13 River In13 CL Spring13 and13 S Leoneditors Proceedings of two symposia Restoring native fish to the lower ColoradoRiver13 interactions13 of native and non-shy‐native13 fishes 13ndash1413 July13 1999 Las13 Vegas13 Nevada13 Restoring13 natural function within a modified riverine environment thelower Colorado River13 8ndash913 July13 1998 U S Fish and13 Wildlife13 Service Southwestern13 Region Albuquerque New Mexico Pages 167-shy‐177

Bertalanffy L Von 1957 Quantitative laws in metabolism13 and growth13 Q Rev Biology 32217 ndash 231

Bingham T B Scheer and C McAda 2003 Propagation facilities in Grand Valley (24 RoadHatchery Horsethief13 Ponds and13 grow-shy‐out ponds) for captive13 rearing13 ofendangered13 fishes for the13 upper13 Colorado13 River basin13 Colorado River RecoveryProgram FY2003 annual project report13 US Fish and13 Wildlife13 Service GrandJunction13 4pp

Birchell G J and K Christopherson 2004 Survival growth and recruitment of larval andjuvenile razorback13 sucker (Xyrauchen texanus) introduced13 into13 floodplain13 depressions13 of the13 Green River Utah13 Final report13 Upper13 Colorado13 RiverEndangered Fish Recovery Program13 Project No C-shy‐6RZ Publication Number 04-shy‐1513 Utah13 Division of Wildlife13 Resources Salt Lake13 City13 Utah13 67 pages

Brannon E L 1993 The perpetual oversight of hatchery programs Fishery Research 1819-shy‐27

Brett J R 1979 Environmental Factors and growth pages 599-shy‐67513 InW S Hoar13 D13 J13 Randall and J R Brett (eds) Fish Physiology Volume 8 Bioenergetics and GrowthAcademic Press New York

Brooks J E 1986 Annual reintroduction and monitoring report for razorback suckerXyrauchen texanus in the Gila River Basin Arizona 1985 US Fish and WildlifeService13 Offices of Endangered13 Species and Fishery13 Resources Albuquerque 23 pp

51

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Brunson13 R E and K D13 Christopherson13 200513 Larval13 razorback13 sucker and bonytailsurvival and13 growth13 in the13 presence13 of nonnative13 fish in the13 Baeser13 floodplainwetland of the middle Green River Final report prepared for Upper13 Colorado RiverBasin Endangered Fish Recovery Program Project No C-shy‐6-shy‐rz-shy‐bt Publication13 No 05-shy‐26 Utah13 Division of Wildlife13 Resources13 Vernal13 32 pp

Bulkley R V and R Pimentel 1983 Temperature preference and avoidance by adultrazorback suckers Transactions of the American Fisheries Society 112601-shy‐607

Burke13 T13 199513 Rearing13 wild razorback13 sucker larvae in13 lake-shy‐side13 backwaters13 LakeMohave ArizonaNevada Proceedings of the Desert Fishes Council 2635

Busacker G P I R Adelman and E M Goolish13 199013 Growth13 Pages 363 ndash 387 in C BSchreck and p B Moyle editors Methods for fish biology American FisheriesSociety Bethesda Maryland

Castro V B Grisdale-shy‐Helland S J Helland T Kristensen S M Jorgensen J Helgrud13 GClaireaux A P Farrell A Krasnov and H Takle 2011 Aerobic training stimulatesgrowth and promotes disease resistance in Atlantic salmon (Salmo salar)Comparative Biochemistry and Physiology -shy‐ Part A Molecular amp IntegrativePhysiology13 160(2) 278-shy‐290

Czapla T E 2002 Facilities plan for the production of endangered fishes to meet statestocking13 plans13 as13 part of the13 Upper13 Colorado13 River Endangered13 Fish RecoveryProgram Upper Colorado River Basin Recovery Implementation Program US Fishand Wildlife Service13 Denver13 9 pp

Davidson W 1997 The effects13 of exercise13 training on teleost fish a review of recentliterature Comput Biochem Physiol 117A67ndash75

Figiel Jr C R 2005 Annual report fiscal year 2004 Willow Beach National13 Fish HatcheryUS Fish and Wildlife13 Service Willow Beach 17 pp

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Gerking13 S D 1978 Ecology of freshwater fish13 production13 Halstead Press13 New13 York

Gustafson W and Q Bradwisch 2000 Wahweap operation and maintenance -shy‐-shy‐ UtahColorado River Recovery Program FY 2000 annual project report Project No 29cUtah13 Division of Wildlife13 Resources Page AZ 3pp

52

13

Hamman R L 1985 Induced spawning of hatchery-shy‐reared13 razorback sucker ProgressivFish Culturist 47(3) 187-shy‐189

Hanson J N 1996 Annual report fiscal year 1996 Willow Beach National Fish HatcheryUS Fish and Wildlife Service13 Willow Beach 9pp

Irving D S Seversen and M Montagne 2004 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2004 annual project13 report Report No 29b US Fish and13 Wildlife13 Service Vernal 3pp

Jorgensen E H and13 M Jobling 1994 Feeding and13 growth13 of exercised13 and13 unexercised13 juvenile Atlantic salmon in freshwater and performance after transfer to seawaterAquaculture International 2 154-shy‐164

Kaeding L R and D B Osmundson 198913 Colorado13 Squawfish13 and13 razorback sucker grow-shy‐out pond studies as part of conservation measures for the green mountain andRuedi reservoir water sales Final report for agreement number 6-shy‐AA-shy‐60-shy‐00150

Koebele13 B P13 198513 Growth and the size hierarchy effect an experimental assessment ofthree proposed mechanisms activity differences disproportional food acquisition13 pysiological stress Environmental Biology of Fishes 12 181-shy‐188

Kretschmann A E and L L Leslie 2006 Razorback sucker (Xyrauchen texanus) status13 reproduction and recruitment in Senator Wash Reservoir CA Final Report13 to USBurea of Reclamation Cooperative Agreement No 00-shy‐FG-shy‐34-shy‐ 0009 p 32 ArizonaGame and Fish Department Phoenix

Marsh13 P13 C13 1987a13 Digestive tract13 contents13 of adult razorback suckers13 in Lake13 MohaveArizona-shy‐Nevada Transactions of the American Fisheries Society 116117-shy‐119

Marsh P C 1987b Native fishes at Buenos Aires National Wildlife Refuge and ArizonaState University Research Park Arizona opportunities for management researchand public13 education13 on13 endangered species13 Proceedings of the Desert13 FishesCouncil 1967-shy‐78

Marsh P C 1994 Rearing native Colorado River fishes in golf course ponds Arizona StateUniversity Tempe 22 + pages

Marsh13 P13 C13 200013 Fish population13 status and evaluation13 in13 the Cibola13 High Levee PondFinal report agreement number 99-shy‐FG-shy‐30-shy‐00051 US Bureau of ReclamationBoulder City13 Nevada13 20 pages

Marsh P C and C A Pacey 1998 Growth of wild adult razorback suckers13 in Lake13 Mohave13 Arizona-shy‐Nevada13 Final report13 US Bureau of Reclamation Boulder City Nevada 25pages + appendices

53

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Marsh P C B R Kesner and C A Pacey 2005 Repatriation as s management strategy13 to13 conserve a critically13 imperiled fish species North American Journal of FisheriesManagement 25 547-shy‐556

Marsh P C and C A Pacey 2005 Immiscibility of native and non-shy‐native13 fishes Pages 59-shy‐63 inMJ13 Brouder13 CL13 Springer13 and CS13 Leon13 editors13 Proceedings of two13 symposia Restoring native fish to the lower Colorado River interactions of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 NV and13 Restoring natural13 function within a modified riverine environment the lower Colorado River13 July13 8-shy‐913 1998 Las Vegas NV US Fish and13 Wildlife13 Service Southwest Region AlbuquerqueNew Mexico

Marsh13 P13 C13 and J13 E Brooks13 198913 Predation13 by ictalurid catfishes as a deterrent13 toreestablishment of hatchery-shy‐reared13 razorback sucker The Southwestern Naturalist34188-shy‐195

Matthews R A 2005 Ichthyopthirus multifiliis Fouquet and Ichthyopthirosis infreshwater13 teleosts13 Pages13 159-shy‐218 in Advances in Parasitology volume 59 J RBaker R Muller D Rollinson (eds) Academic Press

McCarthy13 M S and W L Minckley 1987 Age estimation for razorback sucker (PiscesCatostomidae) from13 Lake Mohave Arizona and Nevada Journal of the Arizona-shy‐Nevada Academy of Science 2187-shy‐97

Minckley13 W L13 198313 Status of the razorback13 sucker13 Xyrauchen texanus (Abbot)13 in13 thelower Colorado River basin13 The Southwestern13 Naturalist13 28(2) 165-shy‐187

Minckley13 W L13 199113 Native fished of the Grand Canyon13 region an obituary13 Pages 124-shy‐177 in Colorado River ecology and dam13 management National Academy PressWashington13 DC

Minckley13 C13 O and M LaBarbara13 199913 Report13 on13 native fish grow-shy‐out facilities13 at Cibolaand Imperial National Wildlife Refuges 1993-shy‐199513 US Fish and13 Wildlife Service13 Parker Fishery Resources Office Parker Arizona

Modde13 T13 199613 Juvenile razorback sucker (Xyrauchen texanus) in a managed wetlandadjacent13 to the Green13 River13 Great13 Basin13 Naturalist13 56375-shy‐376

Modde T KP Burnham and E J Wick 1996 Population status of the razorback sucker13 inthe middle Green River (USA) Conservation13 biology 10 110-shy‐119

Modde13 T13 and G13 B Haines13 200513 Survival13 and growth of stocked razorback13 sucker andbonytail in multiple floodplain wetlands of the middle Green River under resetconditions13 Final report prepared for Upper Colorado13 River13 Basin RecoveryImplimentation Program US Fish and Wildlife Service Vernal 66 pp

54

13

Modde T Z H Bowen and D C Kitcheyan 2005 Spatial and temporal use of a spawning13 site in the middle Green River by wild hatchery-shy‐reared13 razorback suckers13 Transactions of the American Fisheries Society 134937-shy‐944

Mueller13 G13 199213 The native fish work13 group13 -shy‐ a multiagency endeavor to improve thestatus of the razorback sucker in Lake Mohave AZ-shy‐NV13 Proceedings of the DesertFishes Council 2369

Mueller G 1995 A program13 for maintaining the razorback sucker in Lake MohaveAmerican Fisheries Society Symposium 15127-shy‐135

Mueller13 G13 200613 Ecology of the bonytail13 and razorback13 sucker and the role of offchannelhabitats13 in their13 recovery Scientific13 investigations13 report 2006-shy‐5065 US GeologicalSurvey13 Denver

Mueller G and E Wick 1998 Testing of golf course ponds at Page Arizona for suitability13 as grow-shy‐out facility for razorback sucker using surplus fish from13 Ouray NationalFish Hatchery National Park Service US Fish and13 Wildlife13 Service and UtahDivision of Wildlife13 Resources 28 pages

Mueller13 G13 and T13 Burke13 200513 Survival13 of young13 razorback13 sucker (Xyrauchen texanus) inrelation to13 stocking rates13 (fishha)13 and13 in the presence13 or absence13 of predatorcommunities in Lake Mohave Arizona-shy‐Nevada13 Pages13 155-shy‐16313 in Proceedings of two13 symposia restoring native fish to the lower Colorado River interaction13 of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 Nevada US Fish and Wildlife13 Service Southwest Region Albuquerque New Mexico

Mueller13 G13 J13 Carpenter13 and P13 C13 Marsh13 200413 Cibola13 High Levee Pond annual report 2004US Geological Survey Fort Collins13 Science Center13 Colorado13 and Arizona StateUniversity Tempe 23 pages

Nesler T P K Christopherson J M Hudson C W McAda F Pfeifer and T E Czapla 2003An integrated stocking plan for razorback sucker bonytail and Colorado13 pikeminnow for the Upper Colorado River Endangered Fish Recovery ProgramAddendum13 to State Stocking Plans Upper Colorado River Basin Recovery13 Implementation Program 12 pp

Papoulias13 D and W13 L Minckley13 1992 Effects13 of foo availability13 on survival and growth13 of larval razorback suckers13 in ponds Transactions of the American Fisheries Society121340-shy‐355

Paukert13 C P D L Ward13 P J Sponholtz13 and K13 D Hilwig13 Effects13 of repeated hoopnetting13 on bonytail chub13 Journal of Freshwater13 Ecology13 20(4) 649-shy‐653

Pfeifer F M13 C Baker13 and M13 Montagne13 199913 Propagation13 facilities13 in the13 Grand Valley13 (24 Road13 Hatchery13 Horsethief13 Ponds and13 grow-shy‐out ponds) for captive rearing of

55

13

endangered13 fishes for the13 Upper Colorado13 River Basin13 Colorado13 River Recovery13 Program FY 99 annual project report Project No 29a13 US Fish and Wildlife Service13 Grand13 Junction13 5pp

Pfeifer F S Seversen and M Montagne 2003 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2003 annual reportProject No 29b13 US Fish and Wildlife13 Service Vernal13 4pp

Rabago-shy‐Castro J L Sanchez13 J G Perez-shy‐Castaneda R and13 Gonzalez-shy‐Gonzlez A 2006Effects of the prophylactic use of Romet-shy‐3013 and13 copper13 sulfate13 on growth13 condition13 and feeding13 indicies in13 channel13 catfish (Ictalurus punctatus) Aquaculture 253 343-shy‐349

Reinitz GL L E Orme and F N Hitzel 1979 Variations of body compositio and growth13 among strains of rainbow trout Transactions of the American Fisheries Society 108204-shy‐207

Ruppert13 J13 B P B Holden13 and P D Abate 1999 Age estimation and growth of razorbacksucker13 Xyrauchen texanus in Lake13 Mead Nevada Proceedings13 of the Desert FishesCouncil 3040

Schnoor K D and J Logan 2002 Operation and maintenance of JW Mumma nativeaquatic13 species restoration facility Colorado Colorado River Recovery Program FY2002 annual project report13 Project No 29d Colorado13 Division of Wildlife Alamosa3pp

Salisbury13 L13 1998 Factors13 affecting razorback13 sucker growth13 in Lake13 Mohave backwaters13 MS Thesis13 Unviersity13 of Nevada13 Las13 Vegas

Schooley J13 D13 and P C13 Marsh13 2007 Stocking of endangerdd13 razorback13 suckers13 in thelower Colorado River Basin13 over three decades 1974-shy‐2004 North American Journalof Fisheries Management 27 43-shy‐51

Severson S H H M Tyus and G B Haines 1992 An evaluation of feeds for raisingrazorback sucker Xyrauchen texanus Journal of Applied Aquaculture 155-shy‐65

Toney D P 1974 Observations13 on the13 propagation13 and13 rearing13 of two13 endangered species13 in a hatchery environment Proceedings of the Annual Conference of the Western13 Association of State Game and Fish Commissions 54 252-shy‐259

Tyus H M13 1998 Razorback sucker13 (Xyrauchen texanus) recovery plan13 University13 ofColorado Center for Limnology Boulder13 76 pages

Tyus H M13 and13 S H Severson 1990 Growth13 and13 survival of larval razorback suckers fedfive formulated diets The Progressive Fish Culturist 52197-shy‐200

56

13

Ulibarri M E 2003 Annual report fiscal year 2001 Dexter National Fish Hatchery13 andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 26 pages

Ulibarri M E 2003 Annual report fiscal year 2002 Dexter National Fish Hatchery andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 59 pages

USBR 2006 Lower13 Colorado13 River Multi-shy‐Species Conservation Program final fishaugmentation plan Boulder City 19 pp

USFWS 2002 Razorback sucker (Xyraouchen texanus) recovery goals Amendment andsupplement to the Razorback Sucker Recovery Plan13 US Fish and Wildlife Service13 Region 6 Denver13 Colorado

USFWS 1999 Annual report 1999 Ouray National Fish Hatchery Vernal 25pp

USFWS 2004 Management plan for the big-shy‐river13 fishes of the13 lower13 Colorado13 river basinamendment and supplement to the bonytail humpback chub Coloradopikeminnow and razorback sucker recovery plans

USFWS13 2005 Station13 profile13 of the13 Dexter13 National Fish Hatchery13 and Technology CenterUS Fish and Wildlife13 Service Dexter

Valdez R A P G Mangan R Smith and B Nilson 1982 Upper Colorado River fisheriesinvestigations13 inW H Miller J J Valentine D L Archer H M Tyus R A Valdezand L13 Kaeding13 editors13 Colorado River Fishery13 Project13 Part 2 Field13 investigations13 US Bureau of Reclamation Salt Lake City Utah

WBNFH 2004 Culture methods of the endangered razorback sucker Xyrauchen texanusUS Fish and Wildlife13 Service Willow Beach National Fish Hatchery13 8 pp

Ward D 2008 Effects of disease treatments on growth of razorback sucker ReportSubmitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 Inpartial fulfillment of work task C10 agreement number 06FG30039

Ward13 D13 M Childs and W Persons 2007 Factors13 affecting13 growth13 of razorback sucker13 (Xyrauchen texanus) in captivity Literature review and knowledge assessmentReport Submitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 In partial fulfillment of work task C10 agreement number 06FG30039

57

Appendices

Appendix 1 Survey Questions Survey of Razorback Sucker Culture in the

Southwestern United States

The enclosed survey is being distributed by the Arizona Game and Fish Department to razorback sucker culture facilities throughout

the Southwestern United States The purpose of this survey is to consolidate information regarding culture of this species so that

appropriate facility improvements can be considered for Bubbling Ponds Hatchery in Arizona Specifically we wish to increase

growth rate and production efficiency at the hatchery Information gathered in this survey will be summarized in a final report to US

Bureau of Reclamation in Boulder City NV and disseminated to all facilities that participate in the survey A workshop to discuss

the findings of this study as well as to share general information concerning razorback sucker culture will be organized by the

Arizona Game and Fish Department at the conclusion of this study and all participants will be invited

Thank you for taking the time to fill out this survey Please contact Mike Childs if you have questions or would like to discuss the

survey

Mike Childs

mchildssedonanet

(928) 639-1346

(928) 634-1279

Facility_____________________________________ Date___________________

Contact Phone _____________________________

ContactPerson_______________________________

Contact Email _______________________________

1 Water quality ranges at this culture facility

Season

Spring (Mar-May) Summer (Jun-Aug) Fall (Sept-Nov) Winter (Dec-Feb)

Temperature (C)

PH

DO (mgL)

PO4 (mgL)

TDS (mgL)

Hardness (mgL)

CaCO3

Pathogens

37

13

Figure 313 Average growthof razorback suckersexposed to a series of 5 5-shy‐day chemical treatmentsover a 97-shy‐day13 periodError bars representstandard error

Discussion13

Growth13 rates13 observed13 in our study13 (021 ndash 03 mmday) are low compared to those

reported13 in other13 studies13 of razorback sucker13 growth13 (0213 ndash 18 mmday) (Ward et al

2007) Using recirculating water systems for our study required filters to be removed and

replaced during treatments Stress to fish caused by removing and replacing filters within

the tanks as well as repeated water changes may have led to overall higher stress and

reduced growth rates compared to those reported for unconfined fish Growth in fish is

highly variable and is affected by many different physiological and environmental factors

including fish size density temperature amount of space and food (Brett 1979) We

strived to control each of these factors but other factors may have also influenced growth

in our experimental tanks During mid-shy‐summer water temperatures in the treatment

tanks reached 32degC (91degF) At these warm13 temperatures fish are very susceptible to

bacterial13 infections13 The slightly higher growth exhibited by fish in the formalin and

potassium13 permanganate treatments may have been the result of these two chemicals

33

13

being effective at controlling bacterial infections The differences in growth we measured

among treatment groups were not statistically significant and do not appear13 biologically13

meaningful during the relatively short duration of this study (97 days) although the

cumulative effects of slightly reduced growth could be biologically meaningful over longer

time frames

Reductions in growth13 as a result13 o repeated chemical treatments are not likely the

cause of differences in growth rates among facilities that raise razorback suckers

Repeated chemical treatments may have other impacts to overall fitness or long-shy‐term13

survival but these13 effects13 were13 not evident in our study It is more likely that the parasite

outbreaks themselves are the cause of different growth rates among razorback rearing

facilities rather than the chemical treatments used to treat the parasites We recommend

that hatchery managers continue to use the chemicals that are most effective at controlling

ldquoIchrdquo13 at their individual13 facilities

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower Colorado Rive Multi-shy‐species13

Conservation Plan under Work Task C10 We thank Ty Wolters and Tom13 Burke for their

support of this research and Frank Agygos and Dave Billingsly of the Bubbling Ponds Fish

Hatchery13 for their13 technical assistance13 and13 help with13 collecting13 fish

34

13

III13 Razorback Growth Rates at Bubbling Ponds ndash 2009-shy‐2011

Section13 SummaryExperimental studies at Bubbling Ponds Fish Hatchery AZ have strived to understand

factors that affect razorback sucker growth in captivity and identify ways to improve growthrates and maximize size at release Rather than performing experimental studies that wouldrequire major13 rearrangement (and likely reduced production)13 of hatchery operations our13 studies13 used normal variation in production techniques13 and practices13 to isolate factors13 thatmay modify growth rates

Our initial work identified razorback13 growth rates in13 lined ponds at standard fishdensity as 026 to13 028mmday (789 to 843 mmmonth) No significant differences in growthrate were observed among fish that had been in the pond only during the winter13 periodcompared to fish that had been in the pond the entire year indicating that water temperatures13 at Bubbling Ponds are high enough to allow fish to incorporate feed effectively year-shy‐roundHowever these growth rates are lower than most values reported from the literature fromnatural or semi-shy‐natural pond environments No significant differences in13 growth rate wereobserved13 between large and13 small fish13 within the 150 ndash 29 mm TL13 size range Additional worksuggests13 that razorback suckers13 tagged at over 300 mm TL had reduced growth rates (024mmday 73 mmmonth) as would be expected according to a typical Von13 Bertalanfy growthcurve although growth rates13 were only slightly less13 than the average growth rate for thehatchery (027513 mmday 82513 mmmonth)

Sorting13 to13 separate small fish from large fish after the first year of growth is practicedesigned13 to allow smaller fish to ldquocatch uprdquo to larger fish We found that13 this technique doesappear to13 improve growth rates of smaller fish Growth rates of sorted small razorback suckers(029 mmday 87mmmonth)13 were equal to that13 of larger13 fish (028 mmday 8413 mmmonth)indicating that sorting may have helped to offset their original slower growth trajectory

Bubbling Ponds Fish Hatchery grows razorbacks in 6 long deep ponds lined with heavyplastic 2 long deep13 earthen13 (unlined) ponds and three wide shallow earthen ponds The wideshallow ponds13 have historically produced very large fish at low density but have been found tomaintain much lower fish numbers than deeper ponds We found13 that growth13 rates ofrazorbacks kept at high density (4-shy‐700013 fish)13 in a wide shallow pond grew extremely slowly(024 mmday 726 mmmonth) This growth rate is among the slowest of any fish over theyears of our study and demonstrates that13 though the large ponds may produce large fish at lowdensity13 they are unable to overcome high13 fish13 densities

Finally one of the major factors influencing13 fish13 growth13 in hatcheries is disease onemajor summer-shy‐time disease at13 Bubbling Ponds is the ectoparasite Ich (Ichthiopthirusmultifiliis) To investigate the impact Ich has on razorback growth we eradicated fish from thespring and water conveyance ditch that supplies13 water to the hatchery using Rotenone This13 restoration effort was fairly short-shy‐lived (Ich returned to the hatchery within four months) but

35

13

growth13 rates of fish13 reared for four months without Ich present (031 mmday 92 mmmonth)were significantly higher than the following 8 months of growth for those same fish (022mmday 65 mmmonth) This disease-shy‐free growth rate is in fact faster than any13 otherprevious growth rates observed at the hatchery in our study

We conclude that growth rates at the Bubbling Ponds Fish Hatchery are likely as highas possible given the pond densities required to13 meet production goals and the Ich-shy‐infestedwater13 that feeds the facility Sorting practices are successful in helping as many fish as possiblereach stocking length as fast as possible Unlined ponds may be able to grow large fish at lowdensities but whatever factors allow for that growth13 are not able13 to overcome13 high fish densityThus the large lower ponds at Bubbling Ponds may be better utilized via renovation to13 deepenand line them

Disease is the most important factor limiting growth as may be expected to be the caseat many13 hatcheries While the spring renovation was not13 a complete success13 the dramaticreduction of fish populations in that habitat was enough to dramatically13 reduce13 the13 occurrenceof Ich at the hatchery13 Such open spring13 systems feeding a hatchery are a misfortune that canbe expected to transmit disease so we suggest that renovating the spring again to combat13 IchImproved techniques to divert water from13 the springs and more throuough treatment ofstream-shy‐side vegetation may improve the success of chemical treatment Successful renovationwould likely both improve growth rates and reduce chemical costs associated with treating Ichoutbreaks Even13 if complete renovation13 is impossible or impractical an13 effort to reduceinvasive fish density in the springs13 which act a vector for the parasite(and thereby reduce thelikelihood of13 Ich being transmitted into ponds) may still13 show dramatic improvements

36

13

Introduction

Conservation efforts13 for razorback sucker13 (Xyrauchen texanus)13 currently13 depend on

captive rearing and stocking programs Low survival of stocked razorback suckers (Brooks

1986 Marsh13 and13 Brooks13 1989 Marsh13 and13 Pacey13 2005) has13 caused13 target sizes for stocked13

fish to steadily increase in efforts to reduce predation mortality13 (Marsh13 et al13 2005

Schooley and Marsh 2007) Rearing fish to larger sizes at hatcheries comes with increased

costs and creates the need to evaluate husbandry and rearing practices that may affect fish

growth13 We evaluated growth13 rates13 of individual razorback suckers13 in ponds13 at Bubbling

Ponds Fish Hatchery13 using Passive Integrated13 Transponder (PIT) tags13 to13 obtain13 precise

growth information for individual fish so that valid comparisons of growth rates as related

to rearing practices can be made

Due to the critical nature of the razorback sucker stocking program we did not

design experimental studies that would require major rearrangement and potentially

reduce production of hatchery operations Instead our studies used normal variation in

production techniques and practices to isolate factors that may modify growth rates

Though this methodology dramatically limits replication and may limit our ability to

directly13 attribute13 differences in growth13 rates13 to13 the13 variables13 we13 investigate13 we13 were13 able13

to accomplish research goals without altering hatchery operations or impacting

production

From13 2009 through 2011 we conducted a series of observational13 growth13 studies to

determine growth rates of individual razorbacks at Bubbling Ponds The first set of

experiments included13 identifying13 growth13 rates13 in lined13 and13 unlined13 ponds determining

growth13 rates13 of fish at different13 sizes13 in13 relation13 to sorting13 practices and monitoring

razorback growth rates after removing the source of the ectoparasite13 Ich (Ichthiopthirus

multifiliis) from13 the hatchery water source13

Razorback growth rate in lined ponds

Our first growth study documented individual growth rates at normal density in 11

million gallon lined ponds13 over two13 years13 This is the standard13 grow-shy‐out process for

razorbacks13 at Bubbling Ponds We monitored growth of fish for a variety13 of sizes and13 the13

37

13

amount of time in a pond during the growing season These13 data give a snapshot of growth13

rates13 at the13 facility13 and13 provide13 the basis for comparisons throughout our study

Growth rate13 in an unlined pond

In addition13 to 6 ponds lined with heavy plastic13 sheeting13 Bubbling Ponds Fish13

Hatchery maintains two narrow and deep (same dimensions as lined ponds13 Figure13 4)13 and13

three large13 shallow unlined ponds These earthen13 ponds typically have vegetation and

associated aquatic invertebrates that may better simulate natural environments by

providing cover and improved food diversity or quality Therefore these unlined ponds

may be expected to produce higher growth rates and potentially improved survival that is

more similar to growth rates observed in more natural grow-shy‐out facilities13 Historically13 the13

large13 shallow13 ponds have produced very large fish when13 utilized at low13 fish density13 The

narrow13 deep earthen13 ponds are13 used to grow13 fry13 at high density in their first13 year of life

The major downside to unlined ponds is the difficulty in harvesting fish where a lined

pond might take 8-shy‐1013 people13 a half13 day13 to13 harvest13 lined13 ponds13 require13 intensive13 weeding13

to allow seines to be pulled and therefore require many more personnel-shy‐hours13 In addition13

to harvest challenges the shallow earthen ponds tend to suffer from13 dissolved oxygen

crashes during the summer Unlined ponds also may maintain higher13 populations13 of non-shy‐

target species such as bluegill sunfish mosquito fish and bullfrog tadpoles We measured

growth rates of suckers in a large shallow earthen pond for comparison to growth in lined

ponds13

Figure13 4 Lined13 and13 earthen ponds13 of similar dimensions (approx 1000000 gallons first

and second panels) and a large13 shallow13 earthen13 pond (third panel)

38

13

Effect of sorting on growth

Razorback13 suckers13 are13 currently13 sorted13 after their first13 year of growth13 They are13

typically removed from13 one of the13 upper earthen13 ponds and13 split into13 two13 lined13 ponds for

subsequent grow-shy‐out13 The larger13 fish (gt approximately 140 mm) are placed into one pond

and the smaller individuals in another It is possible that the larger fish were more

aggressive or adept13 at taking food so this sorting process is intended to allow smaller fish

to improve their growth rate

Effect of Ich on razorback sucker growth rates

We13 evaluated13 growth13 rates13 of razorback sucker13 in the13 presence13 and absence of the

ectoparasite13 Ich (Ichthiopthirus multifiliis) Ich outbreaks can occur in wild populations13 but

hatcheries13 have13 proven excellent locations13 for Ich because13 of very high fish densities13 which13

facilitate13 the13 transfer13 of Ich13 between13 fish This common fish parasite causes direct mortality13

to razorback13 suckers as well13 as secondary bacterial13 infections13

The open spring and13 ditch13 which13 provides water to the Bubbling13 Ponds Hatchery

has long13 been infested with mosquitofish (Gambusia affinis) that harbor13 the13 Ich parasite13

and allow13 it13 to enter the hatchery with incoming13 water13 The solution13 to13 the13 Ich problem13

was to remove the mosquitofish host using13 Rotenone Razorback13 sucker growth13 rates were13

then tracked in13 the absence of this parasite for 4 months and compared with growth rates

after Ich returned to the pond and from13 previous years

Methods

Razorback growth rate in lined ponds

On May 14 2008 141 razorback suckers were tagged with 12 mm PIT tags (1342

kHz) and placed in Pond 3 (approximately 1100000 gallons13 Figure13 4)13 at Bubbling13 Ponds

Fish Hatchery Fifty-shy‐three of these tags were recovered two months later when a large

Ichthyophthirius multifilis (Ich) outbreak killed many fish in the pond On October 15 2008

an additional13 145 PIT tagged13 fish were13 also placed into Pond13 3 On13 May13 14 2009 Pond13 3

was harvested and a total13 of 141 PIT tagged fish were recovered13 Of the tagged fish13 26 fish

had13 been13 in the13 pond since May13 of 2008 (378 days13 o growth) and 115 had been13 in13 the

39

13 40

pond since October13 15 2008 (211 days13 of growth) Numbers of fish in Pond 3 after the Ich

outbreak and for the majority of the period of growth were between 3 000 and 4000 fish

A Hobotempreg temperature13 logger13 was13 also13 installed13 in Pond 3 one meter below the water

surface13 near13 the13 outflow and13 recorded water temperature every 3 hours to allow analysis

of the effects of water temperature on growth rate (Figure13 5) This Hobotemp data is

representative of other pond temperatures throughout this study

In a second experiment 210 adult13 razorback suckers13 were13 PIT tagged13 on13 May 14

2009 and13 placed13 into13 Pond13 3 upper to13 evaluate13 growth13 rates13 of larger13 razorback suckers13 at

Bubbling13 Ponds Hatchery13 under current13 rearing13 conditions13 Size of these fish at tagging13

was (mean = 285 mm range = 205 ndash 396 mm) These fish remained in the pond for 257

days and were harvested on Jan 25 2010 to provide information on growth rates of larger

razorback suckers13 under13 current rearing conditions

Figure 513 Temperatures (degC) inrearing pond at BubblingPonds Hatchery from July toSept 2009 (top graph)13 andfrom Nov to Dec 2009 (Lowergraph) Temperaturesrecorded with a Hobotempregremote data logger13 every 3hours

13

Growth rate13 in an unlined pond

To document razorback sucker growth in earthen ponds we introduced13 225 tagged13

razorback suckers13 into13 Pond13 1 lower13 (Figure 4) in February 3 2010 Additional tagged fish

from13 other studies were added to the pond throughout the growing season and the density

of 1 lower reached a maximum13 of nearly 7000 fish in early summer 2010 Density was

reduced to approximately 6000 fish by capturing fish with hoop nets on June 3 2010 54 of

these fish were tagged fish and returned to 1 lower after being weighed and measured The

pond was harvested on January13 2713 2011 and a total13 of 254 tagged fish out13 of 4296 fish

total were removed from13 the pond The pond was harvested on January 27 2011 (358 days13

of growth) and the tagged fish were weighed and measured Total number of razorbacks in

the pond at harvest13 was 4296

Effect of sorting practices on growth rates

On March 1113 200913 Pond13 5 upper was13 harvested13 and13 split into13 two13 separate13 groups

Two hundred of the smaller fish (average size = 122 mm TL) were PIT tagged and placed

into13 Pond13 7 upper and13 200 of the13 larger13 fish (average = 160 mm TL) were PIT tagged and

placed int Pond13 8 upper Density13 in Pond13 7 was13 4500 fish and13 in Pond13 8 there13 were13 6500

fish These ponds were then harvested after 1 year and growth rates were compared to

give information on the effects of current sorting practices Hobotempreg temperature

loggers were installed in13 Ponds 7 and13 8 during13 the13 grow-shy‐out period with13 water13

temperature recorded every 2 hours13 (Figure13 6)

Effect of Ich on razorback sucker growth rates

Bubbling Ponds spring was treated with Rotenone (CFT Legumine 5) at a

concentration of 2 ppm13 to remove all mosquitofish from13 the spring The treatment

consisted of two treatments 6 hours in duration on two consecutive days (April 12 -shy‐ 13)

using13 drip13 stations13 and13 backpack sprayers13 followed13 by13 an13 additional 6 hours13 of

detoxification using sodium13 permanganate Although 12 mosquitofish were captured in the

spring pond the week following the treatments subsequent minnow trapping (20 traps

checked13 daily13 for 3 weeks) did not capture any additional fish until August 11 2010 when

41

13

juvenile mosquitofish were again detected in the spring pond Minnow traps have

subsequently been set daily with several hundred individuals removed To evaluate if Ich

was also again present in the spring we captured 15 mosquitofish from13 the spring pond on

three separate days and placed them13 in an aquaria at 25 degC with 5 longfin dace known to be

free of Ich These fish were monitored for 2 weeks with no signs of Ich developing This

indicates that even though mosquitofish have returned to the spring pond the parasite is no

longer present13 although how13 long13 this condition13 will13 persist13 is unknown13

On May 1113 201013 200 juvenile razorback13 suckers were harvested out13 of Pond 5

upper (2009 year Class from13 Dexter National Fish Hatchery) and were PIT tagged and

placed into Pond 8 to evaluate if growth rates at bubbling ponds hatchery have improved

following the renovation of the spring and the removal of the Ich parasite Unfortunately13

on Sept13 8 2010 Ich was13 again13 detected13 in Pond 8 and the pond was immediately seined

and 74 tagged fish were measured to obtain growth information for the 4-shy‐month period

during13 which13 the13 pond13 was13 Ich-shy‐free13

Figure13 6 Temperatures (degC) in rearingponds 7 and 8 at Bubbling Ponds Hatchery13 from March 2009 ndash March 201013 pond 7(top13 graph)13 and13 pond 8 (Lower13 graph)13 Temperatures recorded with a Hobotempregremote data logger every 3 hours

42

13

Results

Growth in Lined Ponds

Razorback suckers13 that had been13 in13 Pond 8 upper for the13 entire13 year13 grew an13

average of 0263 mmday (789 mmmonth) and razorback suckers that had been in the

pond for 7 months (Oct -shy‐ May) grew13 on13 average of 028 mmday (843 mmmonth) (Figure13

7) These growth13 rates13 did not significantly13 differ Fish density13 in Pond 3 during13 the13

majority of the growth period was13 00032 ndash 00036 fishgallon13 Additionally no13 significant

differences in growth rate were observed between fish smaller than 210 mm TL and fish

larger than 210 mm TL when all recaptured fish were combined

We also measured the growth rate of very large fish in a lined pond On Jan13 2513 201013

156 adult fish with PIT tags were recovered from13 Pond 3 upper13 These fish were13 in the13

pond for 257 days and experienced an average13 growth13 rate13 of 024mmday or 73

mmmonth (Figure13 7)13 This growth13 rate13 is slightly13 lower13 than13 the13 average13 growth13 rate13

observed13 at Bubbling13 Ponds Hatchery in other studies (0275 mmday 825 mmmonth)

but may not be biologically meaningful We would expect larger13 fish to13 have13 reduced

growth rates according to a typical Von Bertalanfy growth model (Bertalanffy 1957) but it

appears that13 over the size range we evaluated (300 -shy‐ 450 mm TL) growth rates have not

slowed significantly compared to that of smaller13 fish grown at Bubbling Ponds13 Hatchery

Growth13 of razorback suckers13 is known13 to13 slow as13 fish reach13 larger13 sizes but it appears13 this13

reduced growth rate may not really start to be biologically meaningful at Bubbling Ponds

Hatchery13 until razorback suckers13 exceed 450 mm TL

Growth in unlined ponds

Growth13 rates13 for the13 fish recaptured13 during13 the Pond 1 lower13 thinning13 (120 days13 in

the pond) was 024 plusmn 003 mmday (729 plusmn 090 mmmonth) (Figure13 8)13 Fish13 that were13 in

the pond for nearly the entire year grew13 an13 average13 of 024 plusmn 001 mmday (726 plusmn 027

mmmonth) These growth rates are surprisingly the lowest measured growth rates for

any part of our study and differ significantly from13 every other measured growth rate

except very large13 fish (Figure13 9)13 Separating13 out13 large fish that13 were in13 the pond for the

entire year makes no difference fish that were added to the pond at TL lt300 mm grew

43

13

Gro

wth

Rat

e (m

md

ay)

020

026

032

0244 plusmn 001 mmday (733 plusmn 028 mmmonth) and and those with TL gt= 300 mm at the

start of the experiment grew 022 plusmn 003 mmday (651 plusmn 101 mmmonth)

Razorback Growth Rates in Lined Ponds

Figure 7 Growth ofrazorback suckers in(mmday plusmn standard error)in Pond 8 upper in 2008-shy‐2009 An ANOVA did notdetect any significantdifferences

7 Months Full Year 300+ mm fish

Effects of sorting on growth

One hundred and seventy five tagged razorback suckers were recovered from13 Pond

8 upper13 on March13 24 2010 (378 days13 of growth)13 These were13 the13 larger sorted13 fish (gt140

mm TL) that came out of Pond13 5 on March13 11 2009 One13 hundred and13 twenty13 two13 tagged13

razorback suckers were also recovered from13 Pond13 7 upper on March13 31 2010 (385 days13 of

growth)13 These were13 the13 smaller sorted13 fish (lt140 mm TL) that came out of Pond13 5 on

March 1113 200913 No significant differences in growth rate (mmday) were observed among

larger fish in Pond 8 and smaller fish in Pond 7 (pgt005 ANOVA) (Figure 10)13 indicating

that13 sorting may have helped to offset the original slower growth trajectory of the smaller

fish Temperatures of Ponds 7 and 8 upper remained similar throughout the year13 (Figure

5)

44

13

13

13

Gro

wth

Rat

e (m

md

ay)

Gro

wth

Rat

e (m

md

ay)

020

026

032

020

026

032

Razorback Growth in an Unlined Pond

Figure 8 Growth of razorbacksuckers (mmday plusmn standard error) in Pond 1 lower (an unlined pond)in 2010-shy‐2011 An ANOVA did notdetect any significant differences

6 Months 12 Months lt 300 mm Fish 300+ mm Fish Growth Growth

Lined vs Earthen Ponds 1 year of growth

Figure 9 Growth of razorbacksuckers (mmday plusmn standard error) in lined and unlined ponds A t-shy‐test13 did not detect a significantdifference

Lined Pond Unlined Pond 1 Yr Growth 1 Yr Growth

45

13

Effect of Sorting G

row

th R

ate

(mm

day

) G

row

th R

ate

(mm

day

)

032

020

026

032

020

026

Smaller Fish Larger Fish

Effect of Ich

Figure 10 Average growthof razorback suckers(mmday plusmn standard error)that were size-shy‐sorted intosmall fish (pond 7) and largefish (pond 8) populations At-shy‐test did not detect asignificant difference

Figure 11 Average growth ofrazorback suckers (mmday plusmnstandard error) after Ich wasremovd from the hatcheryrsquos springand after Ich was again detected inthe pond The growth rate withoutIch is significantly higher than boththe rate after Ich and the ourstudyrsquos average annual growth ratein lined ponds (ANOVA p =00003)

Growth without Ich Growth With Ich Average Annual 4 months 4 months Growth Rate

46

13

Effect of Ich on razorback sucker growth rates

Seventy-shy‐four13 tagged13 razorback suckers13 were13 recovered from13 Pond 8 on September

15 2010 These fish had13 been13 in the pond for 4 months and experienced a growth rate of

032 mmday or 97 mmmonth (Figure13 11)13 This growth13 rate13 is significantly higher (p =

005 two sample t-shy‐test) than the mean growth rate for the same group13 of tagged fish after

Ich detection (022 mmday or 65 mmmonth) and significantly higher than any other

individual growth13 rates13 observed13 to13 date13 at Bubbling13 Ponds Hatchery13 (Figure13 11)13 If this13

growth13 rate13 were13 extended throughout13 the entire13 year13 fish on average from13 Ich-shy‐free13 ponds13

would be 16 mm longer than fish from13 ponds infested with Ich Studies conducted at

Bubbling Ponds hatchery in 2008 (Ward 2008) did not reveal any effects of the treatment

chemicals on razorback sucker growth rates so it13 is likely that13 the parasite outbreaks

themselves are causing reducing growth rates rather than the chemicals used to treat the

parasites13

Conclusions

Our results suggest that under typical hatchery operations (maximizing number of

fish produced)13 the growth13 rate13 of razorback13 suckers13 is relatively13 consistent at Bubbling13

Ponds hatchery13 at 02-shy‐03 mmday (6-shy‐9 mmmonth)13 but is lower than growth13 rates13 at

other13 facilities (02 ndash 18 mmday Ward et al 2007)13 This growth13 rate13 has13 been13 constant in

both lined and unlined ponds and at all fish densities we were able to measure To achieve13

growth13 rates13 substantially higher than this will likely require13 significant changes in rearing

practices that may not be practical in order to reach numerical production13 goals

Temperature is a key variable in fish growth but seasonal growth patterns

described13 above13 (Figure13 5) demonstrate that water temperatures are high enough in

winter to maintain razorback growth Differences in water temperature by season

currently13 do not fluctuate more than 10degC at Bubbling Ponds because of the continuous

supply of water flowing through each pond (approx 225 gallonsmin) These high water

flows appear to keep pond temperatures within the thermal preference13 for razorback

suckers13 (1213 -shy‐ 28 degC Bulkley and Pimentel 1983) throughout the entire year with

temperatures rarely dropping13 below 16deg13 C (Figures 513 6)13

47

13

Fish density is another key variable in fish growth and though the number of fish in

a pond during our study ranged from13 3000 to 700013 fish we13 did not find any13 correlation13

between13 density and growth rate13 This might yield two conclusions First13 razorback

growth13 may be changed equally13 by13 densities13 at the13 hatchery13 (ie13 a density13 of 3000 fish in a

pond is as stressful13 for razorbacks as a density13 of 7000 fish) An alternative is that other

factors13 such as disease outbreaks have13 stronger13 control over fish growth13 than13 density13

Fish density13 would13 have13 to13 be13 experimentally manipulated to test13 this13 and hatchery

operations (producing the maximum13 number of fish) prevented our manipulating density13

in ponds for this13 work The trouble with manipulating density demonstrates the difficulties

associated with changing13 hatchery13 practices experimenting with density would have

prevented BPH from13 meeting13 production13 goals Given that the stocking of smaller

razorbacks has met with very little success perhaps BPH goals could be changed from13

producing 12000 fish at 300+ mm per year to a smaller number of very large fish each

year Growing13 fewer13 larger13 fish could potentially be accomplished in the same time frame

as more smaller fish but a better understanding of how density alters growth rate would

be required to be confident13 of this

The very slow growth13 in the13 earthen13 unlined13 Pond 1 lower13 was very surprising We13

had13 anticipated13 that the13 diversified diet13 cover and13 other13 habitat features13 provided by13

unlined ponds would yield dramatically increased growth rates However these traits were

not enough to offset high fish densities and in fact the unlined pond in our study13 suffered

mortality to bring densities down to that observed normally in lined ponds

Our data13 suggest13 that razorbacks13 sucker13 growth13 rates13 are13 higher in lined13 ponds13

However we13 think the reasons13 for the13 very slow growth we observed13 in the13 unlined13 pond13

in our study13 is instead13 linked13 to13 the13 usage13 of Pond 1 lower13 during13 the13 study13 rather13 than13

intrinsic13 slow growth13 in earthen13 ponds First the pond was at extremely high density for at

least part of the study The volume of Pond 1 lower has not been estimated but hatchery

managers suggest 1500-shy‐2000 fish is an appropriate number of individuals so this pond

was at a very high density for much of the experiment Second dissolved oxygen is often

very low in the13 large13 earthen13 ponds during the heat of summer much lower than that of

lined ponds This will both limit the number of fish that can survive in the pond and almost

certainly13 increases stress13 of these13 fish potentially13 reducing growth13 The DO crashes also13

48

13

limit the amount of feed hatchery managers can give fish in these ponds sometimes for

days or weeks at a time which further reduces growth during warm13 weather

Our data13 suggests that13 growth rates at the Bubbling13 Ponds Fish Hatchery are likely

as high as possible given13 the pond densities required to meet production goals and the Ich-shy‐

infested water that feeds the facility Sorting practices are successful in helping as many

fish as possible reach stocking length as fast as possible Unlined ponds may be able to

grow13 large13 fish at low13 densities13 but whatever factors allow13 for that13 growth are not13 able to

overcome high fish density The removal of invasive13 fis that act as13 a host for the13 parasite13

Ich fish from13 the Bubbling13 Ponds spring13 allowed the highest13 growth rate at 032 mmday13

(96 mmmonth) but that growth rate decreased again as Ich re-shy‐infested13 the13 hatchery13

Consistently13 achieving13 growth13 rates13 as high or substantially13 higher than13 this13 will likely13

require13 significant changes in rearing practices that may not be practical in order to13 reach13

numerical production13 goals

Two major changes that might result in higher growth rates are substantially

reducing fish density and modifying the way spring water is delivered to the facility (via

either repeated chemical treatments or enclosed concrete water diversions) to eliminate

Ich from13 the hatchery source water Other potential changes not address by our work

include13 flow-shy‐training razorbacks much previous literature including MSCP-shy‐funded13 work

on razorback suckers13 suggests13 that fish growing13 in flowing water will grow13 faster than fish

in still water (Jorgensen and Jobling 1994) Furthermore there are a wide variety of

potential benefits associated with growing13 fish13 in flowing13 water in addition13 to increased

growth13 rates13 (Davidson13 199713 Castro13 et al13 2011) Another option13 for increasing13 growth13

rates13 include13 changing to13 intensive13 culture13 in large circular13 tanks

Finally given that the stocking of smaller razorbacks has met with very little

success13 perhaps13 BPH13 goals13 could13 be13 changed from13 producing 12000 fish at 300+ mm per

year to a smaller number of very large fish each year Growing fewer larger fish could

potentially be accomplished in the same time frame as more smaller fish but a better

understanding13 of how density13 alters growth13 rate13 would13 be13 required to13 be13 confident of this

49

13

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower13 Colorado13 River Multi-shy‐Species13

Conservation Program13 (LCRMSCP) under Work Task C10 We13 thank Ty Wolters13 Tom13

Burke13 and Eric13 Volkman for their support of this research and Frank Agygos and Dave

Billingsly13 of the Bubbling13 Ponds Fish Hatchery13 for their willingness to participate in13 this

research13 and13 for their technical assistance We also thank the LCRMSCP fish group from13

Boulder City13 NV for their assistance with harvesting13 ponds and tagging13 fish13

50

13

Literature13 CitedAnders P J 1998 Conservation aquaculture and endangered species can objective science13

prevail13 over risk13 anxiety Fisheries 23(11) 28-shy‐31

Anderson R O and R M Nuemann 1996 Length weight and associated structural indicesPages 447 ndash 482 in B R Murphy13 and D13 W Willis13 editors13 Fisheries techniques13 2ndedtion American Fisheries13 Society13 Bethesda13 Maryland

Bain M B J T Finn and H E Brooks 1988 Streamflow regulation and fish communitystructure13 Ecology13 69382-shy‐392

Bays J H Zarbock R Whitman and T Murphy 2005 Conceptual design and managementof native13 fish refugia on the13 lower13 Colorado13 River In13 CL Spring13 and13 S Leoneditors Proceedings of two symposia Restoring native fish to the lower ColoradoRiver13 interactions13 of native and non-shy‐native13 fishes 13ndash1413 July13 1999 Las13 Vegas13 Nevada13 Restoring13 natural function within a modified riverine environment thelower Colorado River13 8ndash913 July13 1998 U S Fish and13 Wildlife13 Service Southwestern13 Region Albuquerque New Mexico Pages 167-shy‐177

Bertalanffy L Von 1957 Quantitative laws in metabolism13 and growth13 Q Rev Biology 32217 ndash 231

Bingham T B Scheer and C McAda 2003 Propagation facilities in Grand Valley (24 RoadHatchery Horsethief13 Ponds and13 grow-shy‐out ponds) for captive13 rearing13 ofendangered13 fishes for the13 upper13 Colorado13 River basin13 Colorado River RecoveryProgram FY2003 annual project report13 US Fish and13 Wildlife13 Service GrandJunction13 4pp

Birchell G J and K Christopherson 2004 Survival growth and recruitment of larval andjuvenile razorback13 sucker (Xyrauchen texanus) introduced13 into13 floodplain13 depressions13 of the13 Green River Utah13 Final report13 Upper13 Colorado13 RiverEndangered Fish Recovery Program13 Project No C-shy‐6RZ Publication Number 04-shy‐1513 Utah13 Division of Wildlife13 Resources Salt Lake13 City13 Utah13 67 pages

Brannon E L 1993 The perpetual oversight of hatchery programs Fishery Research 1819-shy‐27

Brett J R 1979 Environmental Factors and growth pages 599-shy‐67513 InW S Hoar13 D13 J13 Randall and J R Brett (eds) Fish Physiology Volume 8 Bioenergetics and GrowthAcademic Press New York

Brooks J E 1986 Annual reintroduction and monitoring report for razorback suckerXyrauchen texanus in the Gila River Basin Arizona 1985 US Fish and WildlifeService13 Offices of Endangered13 Species and Fishery13 Resources Albuquerque 23 pp

51

13

Brunson13 R E and K D13 Christopherson13 200513 Larval13 razorback13 sucker and bonytailsurvival and13 growth13 in the13 presence13 of nonnative13 fish in the13 Baeser13 floodplainwetland of the middle Green River Final report prepared for Upper13 Colorado RiverBasin Endangered Fish Recovery Program Project No C-shy‐6-shy‐rz-shy‐bt Publication13 No 05-shy‐26 Utah13 Division of Wildlife13 Resources13 Vernal13 32 pp

Bulkley R V and R Pimentel 1983 Temperature preference and avoidance by adultrazorback suckers Transactions of the American Fisheries Society 112601-shy‐607

Burke13 T13 199513 Rearing13 wild razorback13 sucker larvae in13 lake-shy‐side13 backwaters13 LakeMohave ArizonaNevada Proceedings of the Desert Fishes Council 2635

Busacker G P I R Adelman and E M Goolish13 199013 Growth13 Pages 363 ndash 387 in C BSchreck and p B Moyle editors Methods for fish biology American FisheriesSociety Bethesda Maryland

Castro V B Grisdale-shy‐Helland S J Helland T Kristensen S M Jorgensen J Helgrud13 GClaireaux A P Farrell A Krasnov and H Takle 2011 Aerobic training stimulatesgrowth and promotes disease resistance in Atlantic salmon (Salmo salar)Comparative Biochemistry and Physiology -shy‐ Part A Molecular amp IntegrativePhysiology13 160(2) 278-shy‐290

Czapla T E 2002 Facilities plan for the production of endangered fishes to meet statestocking13 plans13 as13 part of the13 Upper13 Colorado13 River Endangered13 Fish RecoveryProgram Upper Colorado River Basin Recovery Implementation Program US Fishand Wildlife Service13 Denver13 9 pp

Davidson W 1997 The effects13 of exercise13 training on teleost fish a review of recentliterature Comput Biochem Physiol 117A67ndash75

Figiel Jr C R 2005 Annual report fiscal year 2004 Willow Beach National13 Fish HatcheryUS Fish and Wildlife13 Service Willow Beach 17 pp

Figiel Jr C R M E Ulibarri G Carmichael J Seals and J N Hanson 2005 Intensive13 fish13 culture of warmwater native fishes at a coldwater fish hatchery Pages 164-shy‐16613 inProceedings of two symposia restoring native fish to the lower Colorado13 River13 interaction13 of native13 and13 non-shy‐native13 fishes July13 13-shy‐1413 1999 Las Vegas Nevada USFish and Wildlife Service Southwest Region Albuquerque New Mexico

Gerking13 S D 1978 Ecology of freshwater fish13 production13 Halstead Press13 New13 York

Gustafson W and Q Bradwisch 2000 Wahweap operation and maintenance -shy‐-shy‐ UtahColorado River Recovery Program FY 2000 annual project report Project No 29cUtah13 Division of Wildlife13 Resources Page AZ 3pp

52

13

Hamman R L 1985 Induced spawning of hatchery-shy‐reared13 razorback sucker ProgressivFish Culturist 47(3) 187-shy‐189

Hanson J N 1996 Annual report fiscal year 1996 Willow Beach National Fish HatcheryUS Fish and Wildlife Service13 Willow Beach 9pp

Irving D S Seversen and M Montagne 2004 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2004 annual project13 report Report No 29b US Fish and13 Wildlife13 Service Vernal 3pp

Jorgensen E H and13 M Jobling 1994 Feeding and13 growth13 of exercised13 and13 unexercised13 juvenile Atlantic salmon in freshwater and performance after transfer to seawaterAquaculture International 2 154-shy‐164

Kaeding L R and D B Osmundson 198913 Colorado13 Squawfish13 and13 razorback sucker grow-shy‐out pond studies as part of conservation measures for the green mountain andRuedi reservoir water sales Final report for agreement number 6-shy‐AA-shy‐60-shy‐00150

Koebele13 B P13 198513 Growth and the size hierarchy effect an experimental assessment ofthree proposed mechanisms activity differences disproportional food acquisition13 pysiological stress Environmental Biology of Fishes 12 181-shy‐188

Kretschmann A E and L L Leslie 2006 Razorback sucker (Xyrauchen texanus) status13 reproduction and recruitment in Senator Wash Reservoir CA Final Report13 to USBurea of Reclamation Cooperative Agreement No 00-shy‐FG-shy‐34-shy‐ 0009 p 32 ArizonaGame and Fish Department Phoenix

Marsh13 P13 C13 1987a13 Digestive tract13 contents13 of adult razorback suckers13 in Lake13 MohaveArizona-shy‐Nevada Transactions of the American Fisheries Society 116117-shy‐119

Marsh P C 1987b Native fishes at Buenos Aires National Wildlife Refuge and ArizonaState University Research Park Arizona opportunities for management researchand public13 education13 on13 endangered species13 Proceedings of the Desert13 FishesCouncil 1967-shy‐78

Marsh P C 1994 Rearing native Colorado River fishes in golf course ponds Arizona StateUniversity Tempe 22 + pages

Marsh13 P13 C13 200013 Fish population13 status and evaluation13 in13 the Cibola13 High Levee PondFinal report agreement number 99-shy‐FG-shy‐30-shy‐00051 US Bureau of ReclamationBoulder City13 Nevada13 20 pages

Marsh P C and C A Pacey 1998 Growth of wild adult razorback suckers13 in Lake13 Mohave13 Arizona-shy‐Nevada13 Final report13 US Bureau of Reclamation Boulder City Nevada 25pages + appendices

53

13

Marsh P C B R Kesner and C A Pacey 2005 Repatriation as s management strategy13 to13 conserve a critically13 imperiled fish species North American Journal of FisheriesManagement 25 547-shy‐556

Marsh P C and C A Pacey 2005 Immiscibility of native and non-shy‐native13 fishes Pages 59-shy‐63 inMJ13 Brouder13 CL13 Springer13 and CS13 Leon13 editors13 Proceedings of two13 symposia Restoring native fish to the lower Colorado River interactions of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 NV and13 Restoring natural13 function within a modified riverine environment the lower Colorado River13 July13 8-shy‐913 1998 Las Vegas NV US Fish and13 Wildlife13 Service Southwest Region AlbuquerqueNew Mexico

Marsh13 P13 C13 and J13 E Brooks13 198913 Predation13 by ictalurid catfishes as a deterrent13 toreestablishment of hatchery-shy‐reared13 razorback sucker The Southwestern Naturalist34188-shy‐195

Matthews R A 2005 Ichthyopthirus multifiliis Fouquet and Ichthyopthirosis infreshwater13 teleosts13 Pages13 159-shy‐218 in Advances in Parasitology volume 59 J RBaker R Muller D Rollinson (eds) Academic Press

McCarthy13 M S and W L Minckley 1987 Age estimation for razorback sucker (PiscesCatostomidae) from13 Lake Mohave Arizona and Nevada Journal of the Arizona-shy‐Nevada Academy of Science 2187-shy‐97

Minckley13 W L13 198313 Status of the razorback13 sucker13 Xyrauchen texanus (Abbot)13 in13 thelower Colorado River basin13 The Southwestern13 Naturalist13 28(2) 165-shy‐187

Minckley13 W L13 199113 Native fished of the Grand Canyon13 region an obituary13 Pages 124-shy‐177 in Colorado River ecology and dam13 management National Academy PressWashington13 DC

Minckley13 C13 O and M LaBarbara13 199913 Report13 on13 native fish grow-shy‐out facilities13 at Cibolaand Imperial National Wildlife Refuges 1993-shy‐199513 US Fish and13 Wildlife Service13 Parker Fishery Resources Office Parker Arizona

Modde13 T13 199613 Juvenile razorback sucker (Xyrauchen texanus) in a managed wetlandadjacent13 to the Green13 River13 Great13 Basin13 Naturalist13 56375-shy‐376

Modde T KP Burnham and E J Wick 1996 Population status of the razorback sucker13 inthe middle Green River (USA) Conservation13 biology 10 110-shy‐119

Modde13 T13 and G13 B Haines13 200513 Survival13 and growth of stocked razorback13 sucker andbonytail in multiple floodplain wetlands of the middle Green River under resetconditions13 Final report prepared for Upper Colorado13 River13 Basin RecoveryImplimentation Program US Fish and Wildlife Service Vernal 66 pp

54

13

Modde T Z H Bowen and D C Kitcheyan 2005 Spatial and temporal use of a spawning13 site in the middle Green River by wild hatchery-shy‐reared13 razorback suckers13 Transactions of the American Fisheries Society 134937-shy‐944

Mueller13 G13 199213 The native fish work13 group13 -shy‐ a multiagency endeavor to improve thestatus of the razorback sucker in Lake Mohave AZ-shy‐NV13 Proceedings of the DesertFishes Council 2369

Mueller G 1995 A program13 for maintaining the razorback sucker in Lake MohaveAmerican Fisheries Society Symposium 15127-shy‐135

Mueller13 G13 200613 Ecology of the bonytail13 and razorback13 sucker and the role of offchannelhabitats13 in their13 recovery Scientific13 investigations13 report 2006-shy‐5065 US GeologicalSurvey13 Denver

Mueller G and E Wick 1998 Testing of golf course ponds at Page Arizona for suitability13 as grow-shy‐out facility for razorback sucker using surplus fish from13 Ouray NationalFish Hatchery National Park Service US Fish and13 Wildlife13 Service and UtahDivision of Wildlife13 Resources 28 pages

Mueller13 G13 and T13 Burke13 200513 Survival13 of young13 razorback13 sucker (Xyrauchen texanus) inrelation to13 stocking rates13 (fishha)13 and13 in the presence13 or absence13 of predatorcommunities in Lake Mohave Arizona-shy‐Nevada13 Pages13 155-shy‐16313 in Proceedings of two13 symposia restoring native fish to the lower Colorado River interaction13 of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 Nevada US Fish and Wildlife13 Service Southwest Region Albuquerque New Mexico

Mueller13 G13 J13 Carpenter13 and P13 C13 Marsh13 200413 Cibola13 High Levee Pond annual report 2004US Geological Survey Fort Collins13 Science Center13 Colorado13 and Arizona StateUniversity Tempe 23 pages

Nesler T P K Christopherson J M Hudson C W McAda F Pfeifer and T E Czapla 2003An integrated stocking plan for razorback sucker bonytail and Colorado13 pikeminnow for the Upper Colorado River Endangered Fish Recovery ProgramAddendum13 to State Stocking Plans Upper Colorado River Basin Recovery13 Implementation Program 12 pp

Papoulias13 D and W13 L Minckley13 1992 Effects13 of foo availability13 on survival and growth13 of larval razorback suckers13 in ponds Transactions of the American Fisheries Society121340-shy‐355

Paukert13 C P D L Ward13 P J Sponholtz13 and K13 D Hilwig13 Effects13 of repeated hoopnetting13 on bonytail chub13 Journal of Freshwater13 Ecology13 20(4) 649-shy‐653

Pfeifer F M13 C Baker13 and M13 Montagne13 199913 Propagation13 facilities13 in the13 Grand Valley13 (24 Road13 Hatchery13 Horsethief13 Ponds and13 grow-shy‐out ponds) for captive rearing of

55

13

endangered13 fishes for the13 Upper Colorado13 River Basin13 Colorado13 River Recovery13 Program FY 99 annual project report Project No 29a13 US Fish and Wildlife Service13 Grand13 Junction13 5pp

Pfeifer F S Seversen and M Montagne 2003 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2003 annual reportProject No 29b13 US Fish and Wildlife13 Service Vernal13 4pp

Rabago-shy‐Castro J L Sanchez13 J G Perez-shy‐Castaneda R and13 Gonzalez-shy‐Gonzlez A 2006Effects of the prophylactic use of Romet-shy‐3013 and13 copper13 sulfate13 on growth13 condition13 and feeding13 indicies in13 channel13 catfish (Ictalurus punctatus) Aquaculture 253 343-shy‐349

Reinitz GL L E Orme and F N Hitzel 1979 Variations of body compositio and growth13 among strains of rainbow trout Transactions of the American Fisheries Society 108204-shy‐207

Ruppert13 J13 B P B Holden13 and P D Abate 1999 Age estimation and growth of razorbacksucker13 Xyrauchen texanus in Lake13 Mead Nevada Proceedings13 of the Desert FishesCouncil 3040

Schnoor K D and J Logan 2002 Operation and maintenance of JW Mumma nativeaquatic13 species restoration facility Colorado Colorado River Recovery Program FY2002 annual project report13 Project No 29d Colorado13 Division of Wildlife Alamosa3pp

Salisbury13 L13 1998 Factors13 affecting razorback13 sucker growth13 in Lake13 Mohave backwaters13 MS Thesis13 Unviersity13 of Nevada13 Las13 Vegas

Schooley J13 D13 and P C13 Marsh13 2007 Stocking of endangerdd13 razorback13 suckers13 in thelower Colorado River Basin13 over three decades 1974-shy‐2004 North American Journalof Fisheries Management 27 43-shy‐51

Severson S H H M Tyus and G B Haines 1992 An evaluation of feeds for raisingrazorback sucker Xyrauchen texanus Journal of Applied Aquaculture 155-shy‐65

Toney D P 1974 Observations13 on the13 propagation13 and13 rearing13 of two13 endangered species13 in a hatchery environment Proceedings of the Annual Conference of the Western13 Association of State Game and Fish Commissions 54 252-shy‐259

Tyus H M13 1998 Razorback sucker13 (Xyrauchen texanus) recovery plan13 University13 ofColorado Center for Limnology Boulder13 76 pages

Tyus H M13 and13 S H Severson 1990 Growth13 and13 survival of larval razorback suckers fedfive formulated diets The Progressive Fish Culturist 52197-shy‐200

56

13

Ulibarri M E 2003 Annual report fiscal year 2001 Dexter National Fish Hatchery13 andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 26 pages

Ulibarri M E 2003 Annual report fiscal year 2002 Dexter National Fish Hatchery andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 59 pages

USBR 2006 Lower13 Colorado13 River Multi-shy‐Species Conservation Program final fishaugmentation plan Boulder City 19 pp

USFWS 2002 Razorback sucker (Xyraouchen texanus) recovery goals Amendment andsupplement to the Razorback Sucker Recovery Plan13 US Fish and Wildlife Service13 Region 6 Denver13 Colorado

USFWS 1999 Annual report 1999 Ouray National Fish Hatchery Vernal 25pp

USFWS 2004 Management plan for the big-shy‐river13 fishes of the13 lower13 Colorado13 river basinamendment and supplement to the bonytail humpback chub Coloradopikeminnow and razorback sucker recovery plans

USFWS13 2005 Station13 profile13 of the13 Dexter13 National Fish Hatchery13 and Technology CenterUS Fish and Wildlife13 Service Dexter

Valdez R A P G Mangan R Smith and B Nilson 1982 Upper Colorado River fisheriesinvestigations13 inW H Miller J J Valentine D L Archer H M Tyus R A Valdezand L13 Kaeding13 editors13 Colorado River Fishery13 Project13 Part 2 Field13 investigations13 US Bureau of Reclamation Salt Lake City Utah

WBNFH 2004 Culture methods of the endangered razorback sucker Xyrauchen texanusUS Fish and Wildlife13 Service Willow Beach National Fish Hatchery13 8 pp

Ward D 2008 Effects of disease treatments on growth of razorback sucker ReportSubmitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 Inpartial fulfillment of work task C10 agreement number 06FG30039

Ward13 D13 M Childs and W Persons 2007 Factors13 affecting13 growth13 of razorback sucker13 (Xyrauchen texanus) in captivity Literature review and knowledge assessmentReport Submitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 In partial fulfillment of work task C10 agreement number 06FG30039

57

Appendices

Appendix 1 Survey Questions Survey of Razorback Sucker Culture in the

Southwestern United States

The enclosed survey is being distributed by the Arizona Game and Fish Department to razorback sucker culture facilities throughout

the Southwestern United States The purpose of this survey is to consolidate information regarding culture of this species so that

appropriate facility improvements can be considered for Bubbling Ponds Hatchery in Arizona Specifically we wish to increase

growth rate and production efficiency at the hatchery Information gathered in this survey will be summarized in a final report to US

Bureau of Reclamation in Boulder City NV and disseminated to all facilities that participate in the survey A workshop to discuss

the findings of this study as well as to share general information concerning razorback sucker culture will be organized by the

Arizona Game and Fish Department at the conclusion of this study and all participants will be invited

Thank you for taking the time to fill out this survey Please contact Mike Childs if you have questions or would like to discuss the

survey

Mike Childs

mchildssedonanet

(928) 639-1346

(928) 634-1279

Facility_____________________________________ Date___________________

Contact Phone _____________________________

ContactPerson_______________________________

Contact Email _______________________________

1 Water quality ranges at this culture facility

Season

Spring (Mar-May) Summer (Jun-Aug) Fall (Sept-Nov) Winter (Dec-Feb)

Temperature (C)

PH

DO (mgL)

PO4 (mgL)

TDS (mgL)

Hardness (mgL)

CaCO3

Pathogens

37

13

being effective at controlling bacterial infections The differences in growth we measured

among treatment groups were not statistically significant and do not appear13 biologically13

meaningful during the relatively short duration of this study (97 days) although the

cumulative effects of slightly reduced growth could be biologically meaningful over longer

time frames

Reductions in growth13 as a result13 o repeated chemical treatments are not likely the

cause of differences in growth rates among facilities that raise razorback suckers

Repeated chemical treatments may have other impacts to overall fitness or long-shy‐term13

survival but these13 effects13 were13 not evident in our study It is more likely that the parasite

outbreaks themselves are the cause of different growth rates among razorback rearing

facilities rather than the chemical treatments used to treat the parasites We recommend

that hatchery managers continue to use the chemicals that are most effective at controlling

ldquoIchrdquo13 at their individual13 facilities

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower Colorado Rive Multi-shy‐species13

Conservation Plan under Work Task C10 We thank Ty Wolters and Tom13 Burke for their

support of this research and Frank Agygos and Dave Billingsly of the Bubbling Ponds Fish

Hatchery13 for their13 technical assistance13 and13 help with13 collecting13 fish

34

13

III13 Razorback Growth Rates at Bubbling Ponds ndash 2009-shy‐2011

Section13 SummaryExperimental studies at Bubbling Ponds Fish Hatchery AZ have strived to understand

factors that affect razorback sucker growth in captivity and identify ways to improve growthrates and maximize size at release Rather than performing experimental studies that wouldrequire major13 rearrangement (and likely reduced production)13 of hatchery operations our13 studies13 used normal variation in production techniques13 and practices13 to isolate factors13 thatmay modify growth rates

Our initial work identified razorback13 growth rates in13 lined ponds at standard fishdensity as 026 to13 028mmday (789 to 843 mmmonth) No significant differences in growthrate were observed among fish that had been in the pond only during the winter13 periodcompared to fish that had been in the pond the entire year indicating that water temperatures13 at Bubbling Ponds are high enough to allow fish to incorporate feed effectively year-shy‐roundHowever these growth rates are lower than most values reported from the literature fromnatural or semi-shy‐natural pond environments No significant differences in13 growth rate wereobserved13 between large and13 small fish13 within the 150 ndash 29 mm TL13 size range Additional worksuggests13 that razorback suckers13 tagged at over 300 mm TL had reduced growth rates (024mmday 73 mmmonth) as would be expected according to a typical Von13 Bertalanfy growthcurve although growth rates13 were only slightly less13 than the average growth rate for thehatchery (027513 mmday 82513 mmmonth)

Sorting13 to13 separate small fish from large fish after the first year of growth is practicedesigned13 to allow smaller fish to ldquocatch uprdquo to larger fish We found that13 this technique doesappear to13 improve growth rates of smaller fish Growth rates of sorted small razorback suckers(029 mmday 87mmmonth)13 were equal to that13 of larger13 fish (028 mmday 8413 mmmonth)indicating that sorting may have helped to offset their original slower growth trajectory

Bubbling Ponds Fish Hatchery grows razorbacks in 6 long deep ponds lined with heavyplastic 2 long deep13 earthen13 (unlined) ponds and three wide shallow earthen ponds The wideshallow ponds13 have historically produced very large fish at low density but have been found tomaintain much lower fish numbers than deeper ponds We found13 that growth13 rates ofrazorbacks kept at high density (4-shy‐700013 fish)13 in a wide shallow pond grew extremely slowly(024 mmday 726 mmmonth) This growth rate is among the slowest of any fish over theyears of our study and demonstrates that13 though the large ponds may produce large fish at lowdensity13 they are unable to overcome high13 fish13 densities

Finally one of the major factors influencing13 fish13 growth13 in hatcheries is disease onemajor summer-shy‐time disease at13 Bubbling Ponds is the ectoparasite Ich (Ichthiopthirusmultifiliis) To investigate the impact Ich has on razorback growth we eradicated fish from thespring and water conveyance ditch that supplies13 water to the hatchery using Rotenone This13 restoration effort was fairly short-shy‐lived (Ich returned to the hatchery within four months) but

35

13

growth13 rates of fish13 reared for four months without Ich present (031 mmday 92 mmmonth)were significantly higher than the following 8 months of growth for those same fish (022mmday 65 mmmonth) This disease-shy‐free growth rate is in fact faster than any13 otherprevious growth rates observed at the hatchery in our study

We conclude that growth rates at the Bubbling Ponds Fish Hatchery are likely as highas possible given the pond densities required to13 meet production goals and the Ich-shy‐infestedwater13 that feeds the facility Sorting practices are successful in helping as many fish as possiblereach stocking length as fast as possible Unlined ponds may be able to grow large fish at lowdensities but whatever factors allow for that growth13 are not able13 to overcome13 high fish densityThus the large lower ponds at Bubbling Ponds may be better utilized via renovation to13 deepenand line them

Disease is the most important factor limiting growth as may be expected to be the caseat many13 hatcheries While the spring renovation was not13 a complete success13 the dramaticreduction of fish populations in that habitat was enough to dramatically13 reduce13 the13 occurrenceof Ich at the hatchery13 Such open spring13 systems feeding a hatchery are a misfortune that canbe expected to transmit disease so we suggest that renovating the spring again to combat13 IchImproved techniques to divert water from13 the springs and more throuough treatment ofstream-shy‐side vegetation may improve the success of chemical treatment Successful renovationwould likely both improve growth rates and reduce chemical costs associated with treating Ichoutbreaks Even13 if complete renovation13 is impossible or impractical an13 effort to reduceinvasive fish density in the springs13 which act a vector for the parasite(and thereby reduce thelikelihood of13 Ich being transmitted into ponds) may still13 show dramatic improvements

36

13

Introduction

Conservation efforts13 for razorback sucker13 (Xyrauchen texanus)13 currently13 depend on

captive rearing and stocking programs Low survival of stocked razorback suckers (Brooks

1986 Marsh13 and13 Brooks13 1989 Marsh13 and13 Pacey13 2005) has13 caused13 target sizes for stocked13

fish to steadily increase in efforts to reduce predation mortality13 (Marsh13 et al13 2005

Schooley and Marsh 2007) Rearing fish to larger sizes at hatcheries comes with increased

costs and creates the need to evaluate husbandry and rearing practices that may affect fish

growth13 We evaluated growth13 rates13 of individual razorback suckers13 in ponds13 at Bubbling

Ponds Fish Hatchery13 using Passive Integrated13 Transponder (PIT) tags13 to13 obtain13 precise

growth information for individual fish so that valid comparisons of growth rates as related

to rearing practices can be made

Due to the critical nature of the razorback sucker stocking program we did not

design experimental studies that would require major rearrangement and potentially

reduce production of hatchery operations Instead our studies used normal variation in

production techniques and practices to isolate factors that may modify growth rates

Though this methodology dramatically limits replication and may limit our ability to

directly13 attribute13 differences in growth13 rates13 to13 the13 variables13 we13 investigate13 we13 were13 able13

to accomplish research goals without altering hatchery operations or impacting

production

From13 2009 through 2011 we conducted a series of observational13 growth13 studies to

determine growth rates of individual razorbacks at Bubbling Ponds The first set of

experiments included13 identifying13 growth13 rates13 in lined13 and13 unlined13 ponds determining

growth13 rates13 of fish at different13 sizes13 in13 relation13 to sorting13 practices and monitoring

razorback growth rates after removing the source of the ectoparasite13 Ich (Ichthiopthirus

multifiliis) from13 the hatchery water source13

Razorback growth rate in lined ponds

Our first growth study documented individual growth rates at normal density in 11

million gallon lined ponds13 over two13 years13 This is the standard13 grow-shy‐out process for

razorbacks13 at Bubbling Ponds We monitored growth of fish for a variety13 of sizes and13 the13

37

13

amount of time in a pond during the growing season These13 data give a snapshot of growth13

rates13 at the13 facility13 and13 provide13 the basis for comparisons throughout our study

Growth rate13 in an unlined pond

In addition13 to 6 ponds lined with heavy plastic13 sheeting13 Bubbling Ponds Fish13

Hatchery maintains two narrow and deep (same dimensions as lined ponds13 Figure13 4)13 and13

three large13 shallow unlined ponds These earthen13 ponds typically have vegetation and

associated aquatic invertebrates that may better simulate natural environments by

providing cover and improved food diversity or quality Therefore these unlined ponds

may be expected to produce higher growth rates and potentially improved survival that is

more similar to growth rates observed in more natural grow-shy‐out facilities13 Historically13 the13

large13 shallow13 ponds have produced very large fish when13 utilized at low13 fish density13 The

narrow13 deep earthen13 ponds are13 used to grow13 fry13 at high density in their first13 year of life

The major downside to unlined ponds is the difficulty in harvesting fish where a lined

pond might take 8-shy‐1013 people13 a half13 day13 to13 harvest13 lined13 ponds13 require13 intensive13 weeding13

to allow seines to be pulled and therefore require many more personnel-shy‐hours13 In addition13

to harvest challenges the shallow earthen ponds tend to suffer from13 dissolved oxygen

crashes during the summer Unlined ponds also may maintain higher13 populations13 of non-shy‐

target species such as bluegill sunfish mosquito fish and bullfrog tadpoles We measured

growth rates of suckers in a large shallow earthen pond for comparison to growth in lined

ponds13

Figure13 4 Lined13 and13 earthen ponds13 of similar dimensions (approx 1000000 gallons first

and second panels) and a large13 shallow13 earthen13 pond (third panel)

38

13

Effect of sorting on growth

Razorback13 suckers13 are13 currently13 sorted13 after their first13 year of growth13 They are13

typically removed from13 one of the13 upper earthen13 ponds and13 split into13 two13 lined13 ponds for

subsequent grow-shy‐out13 The larger13 fish (gt approximately 140 mm) are placed into one pond

and the smaller individuals in another It is possible that the larger fish were more

aggressive or adept13 at taking food so this sorting process is intended to allow smaller fish

to improve their growth rate

Effect of Ich on razorback sucker growth rates

We13 evaluated13 growth13 rates13 of razorback sucker13 in the13 presence13 and absence of the

ectoparasite13 Ich (Ichthiopthirus multifiliis) Ich outbreaks can occur in wild populations13 but

hatcheries13 have13 proven excellent locations13 for Ich because13 of very high fish densities13 which13

facilitate13 the13 transfer13 of Ich13 between13 fish This common fish parasite causes direct mortality13

to razorback13 suckers as well13 as secondary bacterial13 infections13

The open spring and13 ditch13 which13 provides water to the Bubbling13 Ponds Hatchery

has long13 been infested with mosquitofish (Gambusia affinis) that harbor13 the13 Ich parasite13

and allow13 it13 to enter the hatchery with incoming13 water13 The solution13 to13 the13 Ich problem13

was to remove the mosquitofish host using13 Rotenone Razorback13 sucker growth13 rates were13

then tracked in13 the absence of this parasite for 4 months and compared with growth rates

after Ich returned to the pond and from13 previous years

Methods

Razorback growth rate in lined ponds

On May 14 2008 141 razorback suckers were tagged with 12 mm PIT tags (1342

kHz) and placed in Pond 3 (approximately 1100000 gallons13 Figure13 4)13 at Bubbling13 Ponds

Fish Hatchery Fifty-shy‐three of these tags were recovered two months later when a large

Ichthyophthirius multifilis (Ich) outbreak killed many fish in the pond On October 15 2008

an additional13 145 PIT tagged13 fish were13 also placed into Pond13 3 On13 May13 14 2009 Pond13 3

was harvested and a total13 of 141 PIT tagged fish were recovered13 Of the tagged fish13 26 fish

had13 been13 in the13 pond since May13 of 2008 (378 days13 o growth) and 115 had been13 in13 the

39

13 40

pond since October13 15 2008 (211 days13 of growth) Numbers of fish in Pond 3 after the Ich

outbreak and for the majority of the period of growth were between 3 000 and 4000 fish

A Hobotempreg temperature13 logger13 was13 also13 installed13 in Pond 3 one meter below the water

surface13 near13 the13 outflow and13 recorded water temperature every 3 hours to allow analysis

of the effects of water temperature on growth rate (Figure13 5) This Hobotemp data is

representative of other pond temperatures throughout this study

In a second experiment 210 adult13 razorback suckers13 were13 PIT tagged13 on13 May 14

2009 and13 placed13 into13 Pond13 3 upper to13 evaluate13 growth13 rates13 of larger13 razorback suckers13 at

Bubbling13 Ponds Hatchery13 under current13 rearing13 conditions13 Size of these fish at tagging13

was (mean = 285 mm range = 205 ndash 396 mm) These fish remained in the pond for 257

days and were harvested on Jan 25 2010 to provide information on growth rates of larger

razorback suckers13 under13 current rearing conditions

Figure 513 Temperatures (degC) inrearing pond at BubblingPonds Hatchery from July toSept 2009 (top graph)13 andfrom Nov to Dec 2009 (Lowergraph) Temperaturesrecorded with a Hobotempregremote data logger13 every 3hours

13

Growth rate13 in an unlined pond

To document razorback sucker growth in earthen ponds we introduced13 225 tagged13

razorback suckers13 into13 Pond13 1 lower13 (Figure 4) in February 3 2010 Additional tagged fish

from13 other studies were added to the pond throughout the growing season and the density

of 1 lower reached a maximum13 of nearly 7000 fish in early summer 2010 Density was

reduced to approximately 6000 fish by capturing fish with hoop nets on June 3 2010 54 of

these fish were tagged fish and returned to 1 lower after being weighed and measured The

pond was harvested on January13 2713 2011 and a total13 of 254 tagged fish out13 of 4296 fish

total were removed from13 the pond The pond was harvested on January 27 2011 (358 days13

of growth) and the tagged fish were weighed and measured Total number of razorbacks in

the pond at harvest13 was 4296

Effect of sorting practices on growth rates

On March 1113 200913 Pond13 5 upper was13 harvested13 and13 split into13 two13 separate13 groups

Two hundred of the smaller fish (average size = 122 mm TL) were PIT tagged and placed

into13 Pond13 7 upper and13 200 of the13 larger13 fish (average = 160 mm TL) were PIT tagged and

placed int Pond13 8 upper Density13 in Pond13 7 was13 4500 fish and13 in Pond13 8 there13 were13 6500

fish These ponds were then harvested after 1 year and growth rates were compared to

give information on the effects of current sorting practices Hobotempreg temperature

loggers were installed in13 Ponds 7 and13 8 during13 the13 grow-shy‐out period with13 water13

temperature recorded every 2 hours13 (Figure13 6)

Effect of Ich on razorback sucker growth rates

Bubbling Ponds spring was treated with Rotenone (CFT Legumine 5) at a

concentration of 2 ppm13 to remove all mosquitofish from13 the spring The treatment

consisted of two treatments 6 hours in duration on two consecutive days (April 12 -shy‐ 13)

using13 drip13 stations13 and13 backpack sprayers13 followed13 by13 an13 additional 6 hours13 of

detoxification using sodium13 permanganate Although 12 mosquitofish were captured in the

spring pond the week following the treatments subsequent minnow trapping (20 traps

checked13 daily13 for 3 weeks) did not capture any additional fish until August 11 2010 when

41

13

juvenile mosquitofish were again detected in the spring pond Minnow traps have

subsequently been set daily with several hundred individuals removed To evaluate if Ich

was also again present in the spring we captured 15 mosquitofish from13 the spring pond on

three separate days and placed them13 in an aquaria at 25 degC with 5 longfin dace known to be

free of Ich These fish were monitored for 2 weeks with no signs of Ich developing This

indicates that even though mosquitofish have returned to the spring pond the parasite is no

longer present13 although how13 long13 this condition13 will13 persist13 is unknown13

On May 1113 201013 200 juvenile razorback13 suckers were harvested out13 of Pond 5

upper (2009 year Class from13 Dexter National Fish Hatchery) and were PIT tagged and

placed into Pond 8 to evaluate if growth rates at bubbling ponds hatchery have improved

following the renovation of the spring and the removal of the Ich parasite Unfortunately13

on Sept13 8 2010 Ich was13 again13 detected13 in Pond 8 and the pond was immediately seined

and 74 tagged fish were measured to obtain growth information for the 4-shy‐month period

during13 which13 the13 pond13 was13 Ich-shy‐free13

Figure13 6 Temperatures (degC) in rearingponds 7 and 8 at Bubbling Ponds Hatchery13 from March 2009 ndash March 201013 pond 7(top13 graph)13 and13 pond 8 (Lower13 graph)13 Temperatures recorded with a Hobotempregremote data logger every 3 hours

42

13

Results

Growth in Lined Ponds

Razorback suckers13 that had been13 in13 Pond 8 upper for the13 entire13 year13 grew an13

average of 0263 mmday (789 mmmonth) and razorback suckers that had been in the

pond for 7 months (Oct -shy‐ May) grew13 on13 average of 028 mmday (843 mmmonth) (Figure13

7) These growth13 rates13 did not significantly13 differ Fish density13 in Pond 3 during13 the13

majority of the growth period was13 00032 ndash 00036 fishgallon13 Additionally no13 significant

differences in growth rate were observed between fish smaller than 210 mm TL and fish

larger than 210 mm TL when all recaptured fish were combined

We also measured the growth rate of very large fish in a lined pond On Jan13 2513 201013

156 adult fish with PIT tags were recovered from13 Pond 3 upper13 These fish were13 in the13

pond for 257 days and experienced an average13 growth13 rate13 of 024mmday or 73

mmmonth (Figure13 7)13 This growth13 rate13 is slightly13 lower13 than13 the13 average13 growth13 rate13

observed13 at Bubbling13 Ponds Hatchery in other studies (0275 mmday 825 mmmonth)

but may not be biologically meaningful We would expect larger13 fish to13 have13 reduced

growth rates according to a typical Von Bertalanfy growth model (Bertalanffy 1957) but it

appears that13 over the size range we evaluated (300 -shy‐ 450 mm TL) growth rates have not

slowed significantly compared to that of smaller13 fish grown at Bubbling Ponds13 Hatchery

Growth13 of razorback suckers13 is known13 to13 slow as13 fish reach13 larger13 sizes but it appears13 this13

reduced growth rate may not really start to be biologically meaningful at Bubbling Ponds

Hatchery13 until razorback suckers13 exceed 450 mm TL

Growth in unlined ponds

Growth13 rates13 for the13 fish recaptured13 during13 the Pond 1 lower13 thinning13 (120 days13 in

the pond) was 024 plusmn 003 mmday (729 plusmn 090 mmmonth) (Figure13 8)13 Fish13 that were13 in

the pond for nearly the entire year grew13 an13 average13 of 024 plusmn 001 mmday (726 plusmn 027

mmmonth) These growth rates are surprisingly the lowest measured growth rates for

any part of our study and differ significantly from13 every other measured growth rate

except very large13 fish (Figure13 9)13 Separating13 out13 large fish that13 were in13 the pond for the

entire year makes no difference fish that were added to the pond at TL lt300 mm grew

43

13

Gro

wth

Rat

e (m

md

ay)

020

026

032

0244 plusmn 001 mmday (733 plusmn 028 mmmonth) and and those with TL gt= 300 mm at the

start of the experiment grew 022 plusmn 003 mmday (651 plusmn 101 mmmonth)

Razorback Growth Rates in Lined Ponds

Figure 7 Growth ofrazorback suckers in(mmday plusmn standard error)in Pond 8 upper in 2008-shy‐2009 An ANOVA did notdetect any significantdifferences

7 Months Full Year 300+ mm fish

Effects of sorting on growth

One hundred and seventy five tagged razorback suckers were recovered from13 Pond

8 upper13 on March13 24 2010 (378 days13 of growth)13 These were13 the13 larger sorted13 fish (gt140

mm TL) that came out of Pond13 5 on March13 11 2009 One13 hundred and13 twenty13 two13 tagged13

razorback suckers were also recovered from13 Pond13 7 upper on March13 31 2010 (385 days13 of

growth)13 These were13 the13 smaller sorted13 fish (lt140 mm TL) that came out of Pond13 5 on

March 1113 200913 No significant differences in growth rate (mmday) were observed among

larger fish in Pond 8 and smaller fish in Pond 7 (pgt005 ANOVA) (Figure 10)13 indicating

that13 sorting may have helped to offset the original slower growth trajectory of the smaller

fish Temperatures of Ponds 7 and 8 upper remained similar throughout the year13 (Figure

5)

44

13

13

13

Gro

wth

Rat

e (m

md

ay)

Gro

wth

Rat

e (m

md

ay)

020

026

032

020

026

032

Razorback Growth in an Unlined Pond

Figure 8 Growth of razorbacksuckers (mmday plusmn standard error) in Pond 1 lower (an unlined pond)in 2010-shy‐2011 An ANOVA did notdetect any significant differences

6 Months 12 Months lt 300 mm Fish 300+ mm Fish Growth Growth

Lined vs Earthen Ponds 1 year of growth

Figure 9 Growth of razorbacksuckers (mmday plusmn standard error) in lined and unlined ponds A t-shy‐test13 did not detect a significantdifference

Lined Pond Unlined Pond 1 Yr Growth 1 Yr Growth

45

13

Effect of Sorting G

row

th R

ate

(mm

day

) G

row

th R

ate

(mm

day

)

032

020

026

032

020

026

Smaller Fish Larger Fish

Effect of Ich

Figure 10 Average growthof razorback suckers(mmday plusmn standard error)that were size-shy‐sorted intosmall fish (pond 7) and largefish (pond 8) populations At-shy‐test did not detect asignificant difference

Figure 11 Average growth ofrazorback suckers (mmday plusmnstandard error) after Ich wasremovd from the hatcheryrsquos springand after Ich was again detected inthe pond The growth rate withoutIch is significantly higher than boththe rate after Ich and the ourstudyrsquos average annual growth ratein lined ponds (ANOVA p =00003)

Growth without Ich Growth With Ich Average Annual 4 months 4 months Growth Rate

46

13

Effect of Ich on razorback sucker growth rates

Seventy-shy‐four13 tagged13 razorback suckers13 were13 recovered from13 Pond 8 on September

15 2010 These fish had13 been13 in the pond for 4 months and experienced a growth rate of

032 mmday or 97 mmmonth (Figure13 11)13 This growth13 rate13 is significantly higher (p =

005 two sample t-shy‐test) than the mean growth rate for the same group13 of tagged fish after

Ich detection (022 mmday or 65 mmmonth) and significantly higher than any other

individual growth13 rates13 observed13 to13 date13 at Bubbling13 Ponds Hatchery13 (Figure13 11)13 If this13

growth13 rate13 were13 extended throughout13 the entire13 year13 fish on average from13 Ich-shy‐free13 ponds13

would be 16 mm longer than fish from13 ponds infested with Ich Studies conducted at

Bubbling Ponds hatchery in 2008 (Ward 2008) did not reveal any effects of the treatment

chemicals on razorback sucker growth rates so it13 is likely that13 the parasite outbreaks

themselves are causing reducing growth rates rather than the chemicals used to treat the

parasites13

Conclusions

Our results suggest that under typical hatchery operations (maximizing number of

fish produced)13 the growth13 rate13 of razorback13 suckers13 is relatively13 consistent at Bubbling13

Ponds hatchery13 at 02-shy‐03 mmday (6-shy‐9 mmmonth)13 but is lower than growth13 rates13 at

other13 facilities (02 ndash 18 mmday Ward et al 2007)13 This growth13 rate13 has13 been13 constant in

both lined and unlined ponds and at all fish densities we were able to measure To achieve13

growth13 rates13 substantially higher than this will likely require13 significant changes in rearing

practices that may not be practical in order to reach numerical production13 goals

Temperature is a key variable in fish growth but seasonal growth patterns

described13 above13 (Figure13 5) demonstrate that water temperatures are high enough in

winter to maintain razorback growth Differences in water temperature by season

currently13 do not fluctuate more than 10degC at Bubbling Ponds because of the continuous

supply of water flowing through each pond (approx 225 gallonsmin) These high water

flows appear to keep pond temperatures within the thermal preference13 for razorback

suckers13 (1213 -shy‐ 28 degC Bulkley and Pimentel 1983) throughout the entire year with

temperatures rarely dropping13 below 16deg13 C (Figures 513 6)13

47

13

Fish density is another key variable in fish growth and though the number of fish in

a pond during our study ranged from13 3000 to 700013 fish we13 did not find any13 correlation13

between13 density and growth rate13 This might yield two conclusions First13 razorback

growth13 may be changed equally13 by13 densities13 at the13 hatchery13 (ie13 a density13 of 3000 fish in a

pond is as stressful13 for razorbacks as a density13 of 7000 fish) An alternative is that other

factors13 such as disease outbreaks have13 stronger13 control over fish growth13 than13 density13

Fish density13 would13 have13 to13 be13 experimentally manipulated to test13 this13 and hatchery

operations (producing the maximum13 number of fish) prevented our manipulating density13

in ponds for this13 work The trouble with manipulating density demonstrates the difficulties

associated with changing13 hatchery13 practices experimenting with density would have

prevented BPH from13 meeting13 production13 goals Given that the stocking of smaller

razorbacks has met with very little success perhaps BPH goals could be changed from13

producing 12000 fish at 300+ mm per year to a smaller number of very large fish each

year Growing13 fewer13 larger13 fish could potentially be accomplished in the same time frame

as more smaller fish but a better understanding of how density alters growth rate would

be required to be confident13 of this

The very slow growth13 in the13 earthen13 unlined13 Pond 1 lower13 was very surprising We13

had13 anticipated13 that the13 diversified diet13 cover and13 other13 habitat features13 provided by13

unlined ponds would yield dramatically increased growth rates However these traits were

not enough to offset high fish densities and in fact the unlined pond in our study13 suffered

mortality to bring densities down to that observed normally in lined ponds

Our data13 suggest13 that razorbacks13 sucker13 growth13 rates13 are13 higher in lined13 ponds13

However we13 think the reasons13 for the13 very slow growth we observed13 in the13 unlined13 pond13

in our study13 is instead13 linked13 to13 the13 usage13 of Pond 1 lower13 during13 the13 study13 rather13 than13

intrinsic13 slow growth13 in earthen13 ponds First the pond was at extremely high density for at

least part of the study The volume of Pond 1 lower has not been estimated but hatchery

managers suggest 1500-shy‐2000 fish is an appropriate number of individuals so this pond

was at a very high density for much of the experiment Second dissolved oxygen is often

very low in the13 large13 earthen13 ponds during the heat of summer much lower than that of

lined ponds This will both limit the number of fish that can survive in the pond and almost

certainly13 increases stress13 of these13 fish potentially13 reducing growth13 The DO crashes also13

48

13

limit the amount of feed hatchery managers can give fish in these ponds sometimes for

days or weeks at a time which further reduces growth during warm13 weather

Our data13 suggests that13 growth rates at the Bubbling13 Ponds Fish Hatchery are likely

as high as possible given13 the pond densities required to meet production goals and the Ich-shy‐

infested water that feeds the facility Sorting practices are successful in helping as many

fish as possible reach stocking length as fast as possible Unlined ponds may be able to

grow13 large13 fish at low13 densities13 but whatever factors allow13 for that13 growth are not13 able to

overcome high fish density The removal of invasive13 fis that act as13 a host for the13 parasite13

Ich fish from13 the Bubbling13 Ponds spring13 allowed the highest13 growth rate at 032 mmday13

(96 mmmonth) but that growth rate decreased again as Ich re-shy‐infested13 the13 hatchery13

Consistently13 achieving13 growth13 rates13 as high or substantially13 higher than13 this13 will likely13

require13 significant changes in rearing practices that may not be practical in order to13 reach13

numerical production13 goals

Two major changes that might result in higher growth rates are substantially

reducing fish density and modifying the way spring water is delivered to the facility (via

either repeated chemical treatments or enclosed concrete water diversions) to eliminate

Ich from13 the hatchery source water Other potential changes not address by our work

include13 flow-shy‐training razorbacks much previous literature including MSCP-shy‐funded13 work

on razorback suckers13 suggests13 that fish growing13 in flowing water will grow13 faster than fish

in still water (Jorgensen and Jobling 1994) Furthermore there are a wide variety of

potential benefits associated with growing13 fish13 in flowing13 water in addition13 to increased

growth13 rates13 (Davidson13 199713 Castro13 et al13 2011) Another option13 for increasing13 growth13

rates13 include13 changing to13 intensive13 culture13 in large circular13 tanks

Finally given that the stocking of smaller razorbacks has met with very little

success13 perhaps13 BPH13 goals13 could13 be13 changed from13 producing 12000 fish at 300+ mm per

year to a smaller number of very large fish each year Growing fewer larger fish could

potentially be accomplished in the same time frame as more smaller fish but a better

understanding13 of how density13 alters growth13 rate13 would13 be13 required to13 be13 confident of this

49

13

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower13 Colorado13 River Multi-shy‐Species13

Conservation Program13 (LCRMSCP) under Work Task C10 We13 thank Ty Wolters13 Tom13

Burke13 and Eric13 Volkman for their support of this research and Frank Agygos and Dave

Billingsly13 of the Bubbling13 Ponds Fish Hatchery13 for their willingness to participate in13 this

research13 and13 for their technical assistance We also thank the LCRMSCP fish group from13

Boulder City13 NV for their assistance with harvesting13 ponds and tagging13 fish13

50

13

Literature13 CitedAnders P J 1998 Conservation aquaculture and endangered species can objective science13

prevail13 over risk13 anxiety Fisheries 23(11) 28-shy‐31

Anderson R O and R M Nuemann 1996 Length weight and associated structural indicesPages 447 ndash 482 in B R Murphy13 and D13 W Willis13 editors13 Fisheries techniques13 2ndedtion American Fisheries13 Society13 Bethesda13 Maryland

Bain M B J T Finn and H E Brooks 1988 Streamflow regulation and fish communitystructure13 Ecology13 69382-shy‐392

Bays J H Zarbock R Whitman and T Murphy 2005 Conceptual design and managementof native13 fish refugia on the13 lower13 Colorado13 River In13 CL Spring13 and13 S Leoneditors Proceedings of two symposia Restoring native fish to the lower ColoradoRiver13 interactions13 of native and non-shy‐native13 fishes 13ndash1413 July13 1999 Las13 Vegas13 Nevada13 Restoring13 natural function within a modified riverine environment thelower Colorado River13 8ndash913 July13 1998 U S Fish and13 Wildlife13 Service Southwestern13 Region Albuquerque New Mexico Pages 167-shy‐177

Bertalanffy L Von 1957 Quantitative laws in metabolism13 and growth13 Q Rev Biology 32217 ndash 231

Bingham T B Scheer and C McAda 2003 Propagation facilities in Grand Valley (24 RoadHatchery Horsethief13 Ponds and13 grow-shy‐out ponds) for captive13 rearing13 ofendangered13 fishes for the13 upper13 Colorado13 River basin13 Colorado River RecoveryProgram FY2003 annual project report13 US Fish and13 Wildlife13 Service GrandJunction13 4pp

Birchell G J and K Christopherson 2004 Survival growth and recruitment of larval andjuvenile razorback13 sucker (Xyrauchen texanus) introduced13 into13 floodplain13 depressions13 of the13 Green River Utah13 Final report13 Upper13 Colorado13 RiverEndangered Fish Recovery Program13 Project No C-shy‐6RZ Publication Number 04-shy‐1513 Utah13 Division of Wildlife13 Resources Salt Lake13 City13 Utah13 67 pages

Brannon E L 1993 The perpetual oversight of hatchery programs Fishery Research 1819-shy‐27

Brett J R 1979 Environmental Factors and growth pages 599-shy‐67513 InW S Hoar13 D13 J13 Randall and J R Brett (eds) Fish Physiology Volume 8 Bioenergetics and GrowthAcademic Press New York

Brooks J E 1986 Annual reintroduction and monitoring report for razorback suckerXyrauchen texanus in the Gila River Basin Arizona 1985 US Fish and WildlifeService13 Offices of Endangered13 Species and Fishery13 Resources Albuquerque 23 pp

51

13

Brunson13 R E and K D13 Christopherson13 200513 Larval13 razorback13 sucker and bonytailsurvival and13 growth13 in the13 presence13 of nonnative13 fish in the13 Baeser13 floodplainwetland of the middle Green River Final report prepared for Upper13 Colorado RiverBasin Endangered Fish Recovery Program Project No C-shy‐6-shy‐rz-shy‐bt Publication13 No 05-shy‐26 Utah13 Division of Wildlife13 Resources13 Vernal13 32 pp

Bulkley R V and R Pimentel 1983 Temperature preference and avoidance by adultrazorback suckers Transactions of the American Fisheries Society 112601-shy‐607

Burke13 T13 199513 Rearing13 wild razorback13 sucker larvae in13 lake-shy‐side13 backwaters13 LakeMohave ArizonaNevada Proceedings of the Desert Fishes Council 2635

Busacker G P I R Adelman and E M Goolish13 199013 Growth13 Pages 363 ndash 387 in C BSchreck and p B Moyle editors Methods for fish biology American FisheriesSociety Bethesda Maryland

Castro V B Grisdale-shy‐Helland S J Helland T Kristensen S M Jorgensen J Helgrud13 GClaireaux A P Farrell A Krasnov and H Takle 2011 Aerobic training stimulatesgrowth and promotes disease resistance in Atlantic salmon (Salmo salar)Comparative Biochemistry and Physiology -shy‐ Part A Molecular amp IntegrativePhysiology13 160(2) 278-shy‐290

Czapla T E 2002 Facilities plan for the production of endangered fishes to meet statestocking13 plans13 as13 part of the13 Upper13 Colorado13 River Endangered13 Fish RecoveryProgram Upper Colorado River Basin Recovery Implementation Program US Fishand Wildlife Service13 Denver13 9 pp

Davidson W 1997 The effects13 of exercise13 training on teleost fish a review of recentliterature Comput Biochem Physiol 117A67ndash75

Figiel Jr C R 2005 Annual report fiscal year 2004 Willow Beach National13 Fish HatcheryUS Fish and Wildlife13 Service Willow Beach 17 pp

Figiel Jr C R M E Ulibarri G Carmichael J Seals and J N Hanson 2005 Intensive13 fish13 culture of warmwater native fishes at a coldwater fish hatchery Pages 164-shy‐16613 inProceedings of two symposia restoring native fish to the lower Colorado13 River13 interaction13 of native13 and13 non-shy‐native13 fishes July13 13-shy‐1413 1999 Las Vegas Nevada USFish and Wildlife Service Southwest Region Albuquerque New Mexico

Gerking13 S D 1978 Ecology of freshwater fish13 production13 Halstead Press13 New13 York

Gustafson W and Q Bradwisch 2000 Wahweap operation and maintenance -shy‐-shy‐ UtahColorado River Recovery Program FY 2000 annual project report Project No 29cUtah13 Division of Wildlife13 Resources Page AZ 3pp

52

13

Hamman R L 1985 Induced spawning of hatchery-shy‐reared13 razorback sucker ProgressivFish Culturist 47(3) 187-shy‐189

Hanson J N 1996 Annual report fiscal year 1996 Willow Beach National Fish HatcheryUS Fish and Wildlife Service13 Willow Beach 9pp

Irving D S Seversen and M Montagne 2004 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2004 annual project13 report Report No 29b US Fish and13 Wildlife13 Service Vernal 3pp

Jorgensen E H and13 M Jobling 1994 Feeding and13 growth13 of exercised13 and13 unexercised13 juvenile Atlantic salmon in freshwater and performance after transfer to seawaterAquaculture International 2 154-shy‐164

Kaeding L R and D B Osmundson 198913 Colorado13 Squawfish13 and13 razorback sucker grow-shy‐out pond studies as part of conservation measures for the green mountain andRuedi reservoir water sales Final report for agreement number 6-shy‐AA-shy‐60-shy‐00150

Koebele13 B P13 198513 Growth and the size hierarchy effect an experimental assessment ofthree proposed mechanisms activity differences disproportional food acquisition13 pysiological stress Environmental Biology of Fishes 12 181-shy‐188

Kretschmann A E and L L Leslie 2006 Razorback sucker (Xyrauchen texanus) status13 reproduction and recruitment in Senator Wash Reservoir CA Final Report13 to USBurea of Reclamation Cooperative Agreement No 00-shy‐FG-shy‐34-shy‐ 0009 p 32 ArizonaGame and Fish Department Phoenix

Marsh13 P13 C13 1987a13 Digestive tract13 contents13 of adult razorback suckers13 in Lake13 MohaveArizona-shy‐Nevada Transactions of the American Fisheries Society 116117-shy‐119

Marsh P C 1987b Native fishes at Buenos Aires National Wildlife Refuge and ArizonaState University Research Park Arizona opportunities for management researchand public13 education13 on13 endangered species13 Proceedings of the Desert13 FishesCouncil 1967-shy‐78

Marsh P C 1994 Rearing native Colorado River fishes in golf course ponds Arizona StateUniversity Tempe 22 + pages

Marsh13 P13 C13 200013 Fish population13 status and evaluation13 in13 the Cibola13 High Levee PondFinal report agreement number 99-shy‐FG-shy‐30-shy‐00051 US Bureau of ReclamationBoulder City13 Nevada13 20 pages

Marsh P C and C A Pacey 1998 Growth of wild adult razorback suckers13 in Lake13 Mohave13 Arizona-shy‐Nevada13 Final report13 US Bureau of Reclamation Boulder City Nevada 25pages + appendices

53

13

Marsh P C B R Kesner and C A Pacey 2005 Repatriation as s management strategy13 to13 conserve a critically13 imperiled fish species North American Journal of FisheriesManagement 25 547-shy‐556

Marsh P C and C A Pacey 2005 Immiscibility of native and non-shy‐native13 fishes Pages 59-shy‐63 inMJ13 Brouder13 CL13 Springer13 and CS13 Leon13 editors13 Proceedings of two13 symposia Restoring native fish to the lower Colorado River interactions of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 NV and13 Restoring natural13 function within a modified riverine environment the lower Colorado River13 July13 8-shy‐913 1998 Las Vegas NV US Fish and13 Wildlife13 Service Southwest Region AlbuquerqueNew Mexico

Marsh13 P13 C13 and J13 E Brooks13 198913 Predation13 by ictalurid catfishes as a deterrent13 toreestablishment of hatchery-shy‐reared13 razorback sucker The Southwestern Naturalist34188-shy‐195

Matthews R A 2005 Ichthyopthirus multifiliis Fouquet and Ichthyopthirosis infreshwater13 teleosts13 Pages13 159-shy‐218 in Advances in Parasitology volume 59 J RBaker R Muller D Rollinson (eds) Academic Press

McCarthy13 M S and W L Minckley 1987 Age estimation for razorback sucker (PiscesCatostomidae) from13 Lake Mohave Arizona and Nevada Journal of the Arizona-shy‐Nevada Academy of Science 2187-shy‐97

Minckley13 W L13 198313 Status of the razorback13 sucker13 Xyrauchen texanus (Abbot)13 in13 thelower Colorado River basin13 The Southwestern13 Naturalist13 28(2) 165-shy‐187

Minckley13 W L13 199113 Native fished of the Grand Canyon13 region an obituary13 Pages 124-shy‐177 in Colorado River ecology and dam13 management National Academy PressWashington13 DC

Minckley13 C13 O and M LaBarbara13 199913 Report13 on13 native fish grow-shy‐out facilities13 at Cibolaand Imperial National Wildlife Refuges 1993-shy‐199513 US Fish and13 Wildlife Service13 Parker Fishery Resources Office Parker Arizona

Modde13 T13 199613 Juvenile razorback sucker (Xyrauchen texanus) in a managed wetlandadjacent13 to the Green13 River13 Great13 Basin13 Naturalist13 56375-shy‐376

Modde T KP Burnham and E J Wick 1996 Population status of the razorback sucker13 inthe middle Green River (USA) Conservation13 biology 10 110-shy‐119

Modde13 T13 and G13 B Haines13 200513 Survival13 and growth of stocked razorback13 sucker andbonytail in multiple floodplain wetlands of the middle Green River under resetconditions13 Final report prepared for Upper Colorado13 River13 Basin RecoveryImplimentation Program US Fish and Wildlife Service Vernal 66 pp

54

13

Modde T Z H Bowen and D C Kitcheyan 2005 Spatial and temporal use of a spawning13 site in the middle Green River by wild hatchery-shy‐reared13 razorback suckers13 Transactions of the American Fisheries Society 134937-shy‐944

Mueller13 G13 199213 The native fish work13 group13 -shy‐ a multiagency endeavor to improve thestatus of the razorback sucker in Lake Mohave AZ-shy‐NV13 Proceedings of the DesertFishes Council 2369

Mueller G 1995 A program13 for maintaining the razorback sucker in Lake MohaveAmerican Fisheries Society Symposium 15127-shy‐135

Mueller13 G13 200613 Ecology of the bonytail13 and razorback13 sucker and the role of offchannelhabitats13 in their13 recovery Scientific13 investigations13 report 2006-shy‐5065 US GeologicalSurvey13 Denver

Mueller G and E Wick 1998 Testing of golf course ponds at Page Arizona for suitability13 as grow-shy‐out facility for razorback sucker using surplus fish from13 Ouray NationalFish Hatchery National Park Service US Fish and13 Wildlife13 Service and UtahDivision of Wildlife13 Resources 28 pages

Mueller13 G13 and T13 Burke13 200513 Survival13 of young13 razorback13 sucker (Xyrauchen texanus) inrelation to13 stocking rates13 (fishha)13 and13 in the presence13 or absence13 of predatorcommunities in Lake Mohave Arizona-shy‐Nevada13 Pages13 155-shy‐16313 in Proceedings of two13 symposia restoring native fish to the lower Colorado River interaction13 of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 Nevada US Fish and Wildlife13 Service Southwest Region Albuquerque New Mexico

Mueller13 G13 J13 Carpenter13 and P13 C13 Marsh13 200413 Cibola13 High Levee Pond annual report 2004US Geological Survey Fort Collins13 Science Center13 Colorado13 and Arizona StateUniversity Tempe 23 pages

Nesler T P K Christopherson J M Hudson C W McAda F Pfeifer and T E Czapla 2003An integrated stocking plan for razorback sucker bonytail and Colorado13 pikeminnow for the Upper Colorado River Endangered Fish Recovery ProgramAddendum13 to State Stocking Plans Upper Colorado River Basin Recovery13 Implementation Program 12 pp

Papoulias13 D and W13 L Minckley13 1992 Effects13 of foo availability13 on survival and growth13 of larval razorback suckers13 in ponds Transactions of the American Fisheries Society121340-shy‐355

Paukert13 C P D L Ward13 P J Sponholtz13 and K13 D Hilwig13 Effects13 of repeated hoopnetting13 on bonytail chub13 Journal of Freshwater13 Ecology13 20(4) 649-shy‐653

Pfeifer F M13 C Baker13 and M13 Montagne13 199913 Propagation13 facilities13 in the13 Grand Valley13 (24 Road13 Hatchery13 Horsethief13 Ponds and13 grow-shy‐out ponds) for captive rearing of

55

13

endangered13 fishes for the13 Upper Colorado13 River Basin13 Colorado13 River Recovery13 Program FY 99 annual project report Project No 29a13 US Fish and Wildlife Service13 Grand13 Junction13 5pp

Pfeifer F S Seversen and M Montagne 2003 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2003 annual reportProject No 29b13 US Fish and Wildlife13 Service Vernal13 4pp

Rabago-shy‐Castro J L Sanchez13 J G Perez-shy‐Castaneda R and13 Gonzalez-shy‐Gonzlez A 2006Effects of the prophylactic use of Romet-shy‐3013 and13 copper13 sulfate13 on growth13 condition13 and feeding13 indicies in13 channel13 catfish (Ictalurus punctatus) Aquaculture 253 343-shy‐349

Reinitz GL L E Orme and F N Hitzel 1979 Variations of body compositio and growth13 among strains of rainbow trout Transactions of the American Fisheries Society 108204-shy‐207

Ruppert13 J13 B P B Holden13 and P D Abate 1999 Age estimation and growth of razorbacksucker13 Xyrauchen texanus in Lake13 Mead Nevada Proceedings13 of the Desert FishesCouncil 3040

Schnoor K D and J Logan 2002 Operation and maintenance of JW Mumma nativeaquatic13 species restoration facility Colorado Colorado River Recovery Program FY2002 annual project report13 Project No 29d Colorado13 Division of Wildlife Alamosa3pp

Salisbury13 L13 1998 Factors13 affecting razorback13 sucker growth13 in Lake13 Mohave backwaters13 MS Thesis13 Unviersity13 of Nevada13 Las13 Vegas

Schooley J13 D13 and P C13 Marsh13 2007 Stocking of endangerdd13 razorback13 suckers13 in thelower Colorado River Basin13 over three decades 1974-shy‐2004 North American Journalof Fisheries Management 27 43-shy‐51

Severson S H H M Tyus and G B Haines 1992 An evaluation of feeds for raisingrazorback sucker Xyrauchen texanus Journal of Applied Aquaculture 155-shy‐65

Toney D P 1974 Observations13 on the13 propagation13 and13 rearing13 of two13 endangered species13 in a hatchery environment Proceedings of the Annual Conference of the Western13 Association of State Game and Fish Commissions 54 252-shy‐259

Tyus H M13 1998 Razorback sucker13 (Xyrauchen texanus) recovery plan13 University13 ofColorado Center for Limnology Boulder13 76 pages

Tyus H M13 and13 S H Severson 1990 Growth13 and13 survival of larval razorback suckers fedfive formulated diets The Progressive Fish Culturist 52197-shy‐200

56

13

Ulibarri M E 2003 Annual report fiscal year 2001 Dexter National Fish Hatchery13 andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 26 pages

Ulibarri M E 2003 Annual report fiscal year 2002 Dexter National Fish Hatchery andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 59 pages

USBR 2006 Lower13 Colorado13 River Multi-shy‐Species Conservation Program final fishaugmentation plan Boulder City 19 pp

USFWS 2002 Razorback sucker (Xyraouchen texanus) recovery goals Amendment andsupplement to the Razorback Sucker Recovery Plan13 US Fish and Wildlife Service13 Region 6 Denver13 Colorado

USFWS 1999 Annual report 1999 Ouray National Fish Hatchery Vernal 25pp

USFWS 2004 Management plan for the big-shy‐river13 fishes of the13 lower13 Colorado13 river basinamendment and supplement to the bonytail humpback chub Coloradopikeminnow and razorback sucker recovery plans

USFWS13 2005 Station13 profile13 of the13 Dexter13 National Fish Hatchery13 and Technology CenterUS Fish and Wildlife13 Service Dexter

Valdez R A P G Mangan R Smith and B Nilson 1982 Upper Colorado River fisheriesinvestigations13 inW H Miller J J Valentine D L Archer H M Tyus R A Valdezand L13 Kaeding13 editors13 Colorado River Fishery13 Project13 Part 2 Field13 investigations13 US Bureau of Reclamation Salt Lake City Utah

WBNFH 2004 Culture methods of the endangered razorback sucker Xyrauchen texanusUS Fish and Wildlife13 Service Willow Beach National Fish Hatchery13 8 pp

Ward D 2008 Effects of disease treatments on growth of razorback sucker ReportSubmitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 Inpartial fulfillment of work task C10 agreement number 06FG30039

Ward13 D13 M Childs and W Persons 2007 Factors13 affecting13 growth13 of razorback sucker13 (Xyrauchen texanus) in captivity Literature review and knowledge assessmentReport Submitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 In partial fulfillment of work task C10 agreement number 06FG30039

57

Appendices

Appendix 1 Survey Questions Survey of Razorback Sucker Culture in the

Southwestern United States

The enclosed survey is being distributed by the Arizona Game and Fish Department to razorback sucker culture facilities throughout

the Southwestern United States The purpose of this survey is to consolidate information regarding culture of this species so that

appropriate facility improvements can be considered for Bubbling Ponds Hatchery in Arizona Specifically we wish to increase

growth rate and production efficiency at the hatchery Information gathered in this survey will be summarized in a final report to US

Bureau of Reclamation in Boulder City NV and disseminated to all facilities that participate in the survey A workshop to discuss

the findings of this study as well as to share general information concerning razorback sucker culture will be organized by the

Arizona Game and Fish Department at the conclusion of this study and all participants will be invited

Thank you for taking the time to fill out this survey Please contact Mike Childs if you have questions or would like to discuss the

survey

Mike Childs

mchildssedonanet

(928) 639-1346

(928) 634-1279

Facility_____________________________________ Date___________________

Contact Phone _____________________________

ContactPerson_______________________________

Contact Email _______________________________

1 Water quality ranges at this culture facility

Season

Spring (Mar-May) Summer (Jun-Aug) Fall (Sept-Nov) Winter (Dec-Feb)

Temperature (C)

PH

DO (mgL)

PO4 (mgL)

TDS (mgL)

Hardness (mgL)

CaCO3

Pathogens

37

13

III13 Razorback Growth Rates at Bubbling Ponds ndash 2009-shy‐2011

Section13 SummaryExperimental studies at Bubbling Ponds Fish Hatchery AZ have strived to understand

factors that affect razorback sucker growth in captivity and identify ways to improve growthrates and maximize size at release Rather than performing experimental studies that wouldrequire major13 rearrangement (and likely reduced production)13 of hatchery operations our13 studies13 used normal variation in production techniques13 and practices13 to isolate factors13 thatmay modify growth rates

Our initial work identified razorback13 growth rates in13 lined ponds at standard fishdensity as 026 to13 028mmday (789 to 843 mmmonth) No significant differences in growthrate were observed among fish that had been in the pond only during the winter13 periodcompared to fish that had been in the pond the entire year indicating that water temperatures13 at Bubbling Ponds are high enough to allow fish to incorporate feed effectively year-shy‐roundHowever these growth rates are lower than most values reported from the literature fromnatural or semi-shy‐natural pond environments No significant differences in13 growth rate wereobserved13 between large and13 small fish13 within the 150 ndash 29 mm TL13 size range Additional worksuggests13 that razorback suckers13 tagged at over 300 mm TL had reduced growth rates (024mmday 73 mmmonth) as would be expected according to a typical Von13 Bertalanfy growthcurve although growth rates13 were only slightly less13 than the average growth rate for thehatchery (027513 mmday 82513 mmmonth)

Sorting13 to13 separate small fish from large fish after the first year of growth is practicedesigned13 to allow smaller fish to ldquocatch uprdquo to larger fish We found that13 this technique doesappear to13 improve growth rates of smaller fish Growth rates of sorted small razorback suckers(029 mmday 87mmmonth)13 were equal to that13 of larger13 fish (028 mmday 8413 mmmonth)indicating that sorting may have helped to offset their original slower growth trajectory

Bubbling Ponds Fish Hatchery grows razorbacks in 6 long deep ponds lined with heavyplastic 2 long deep13 earthen13 (unlined) ponds and three wide shallow earthen ponds The wideshallow ponds13 have historically produced very large fish at low density but have been found tomaintain much lower fish numbers than deeper ponds We found13 that growth13 rates ofrazorbacks kept at high density (4-shy‐700013 fish)13 in a wide shallow pond grew extremely slowly(024 mmday 726 mmmonth) This growth rate is among the slowest of any fish over theyears of our study and demonstrates that13 though the large ponds may produce large fish at lowdensity13 they are unable to overcome high13 fish13 densities

Finally one of the major factors influencing13 fish13 growth13 in hatcheries is disease onemajor summer-shy‐time disease at13 Bubbling Ponds is the ectoparasite Ich (Ichthiopthirusmultifiliis) To investigate the impact Ich has on razorback growth we eradicated fish from thespring and water conveyance ditch that supplies13 water to the hatchery using Rotenone This13 restoration effort was fairly short-shy‐lived (Ich returned to the hatchery within four months) but

35

13

growth13 rates of fish13 reared for four months without Ich present (031 mmday 92 mmmonth)were significantly higher than the following 8 months of growth for those same fish (022mmday 65 mmmonth) This disease-shy‐free growth rate is in fact faster than any13 otherprevious growth rates observed at the hatchery in our study

We conclude that growth rates at the Bubbling Ponds Fish Hatchery are likely as highas possible given the pond densities required to13 meet production goals and the Ich-shy‐infestedwater13 that feeds the facility Sorting practices are successful in helping as many fish as possiblereach stocking length as fast as possible Unlined ponds may be able to grow large fish at lowdensities but whatever factors allow for that growth13 are not able13 to overcome13 high fish densityThus the large lower ponds at Bubbling Ponds may be better utilized via renovation to13 deepenand line them

Disease is the most important factor limiting growth as may be expected to be the caseat many13 hatcheries While the spring renovation was not13 a complete success13 the dramaticreduction of fish populations in that habitat was enough to dramatically13 reduce13 the13 occurrenceof Ich at the hatchery13 Such open spring13 systems feeding a hatchery are a misfortune that canbe expected to transmit disease so we suggest that renovating the spring again to combat13 IchImproved techniques to divert water from13 the springs and more throuough treatment ofstream-shy‐side vegetation may improve the success of chemical treatment Successful renovationwould likely both improve growth rates and reduce chemical costs associated with treating Ichoutbreaks Even13 if complete renovation13 is impossible or impractical an13 effort to reduceinvasive fish density in the springs13 which act a vector for the parasite(and thereby reduce thelikelihood of13 Ich being transmitted into ponds) may still13 show dramatic improvements

36

13

Introduction

Conservation efforts13 for razorback sucker13 (Xyrauchen texanus)13 currently13 depend on

captive rearing and stocking programs Low survival of stocked razorback suckers (Brooks

1986 Marsh13 and13 Brooks13 1989 Marsh13 and13 Pacey13 2005) has13 caused13 target sizes for stocked13

fish to steadily increase in efforts to reduce predation mortality13 (Marsh13 et al13 2005

Schooley and Marsh 2007) Rearing fish to larger sizes at hatcheries comes with increased

costs and creates the need to evaluate husbandry and rearing practices that may affect fish

growth13 We evaluated growth13 rates13 of individual razorback suckers13 in ponds13 at Bubbling

Ponds Fish Hatchery13 using Passive Integrated13 Transponder (PIT) tags13 to13 obtain13 precise

growth information for individual fish so that valid comparisons of growth rates as related

to rearing practices can be made

Due to the critical nature of the razorback sucker stocking program we did not

design experimental studies that would require major rearrangement and potentially

reduce production of hatchery operations Instead our studies used normal variation in

production techniques and practices to isolate factors that may modify growth rates

Though this methodology dramatically limits replication and may limit our ability to

directly13 attribute13 differences in growth13 rates13 to13 the13 variables13 we13 investigate13 we13 were13 able13

to accomplish research goals without altering hatchery operations or impacting

production

From13 2009 through 2011 we conducted a series of observational13 growth13 studies to

determine growth rates of individual razorbacks at Bubbling Ponds The first set of

experiments included13 identifying13 growth13 rates13 in lined13 and13 unlined13 ponds determining

growth13 rates13 of fish at different13 sizes13 in13 relation13 to sorting13 practices and monitoring

razorback growth rates after removing the source of the ectoparasite13 Ich (Ichthiopthirus

multifiliis) from13 the hatchery water source13

Razorback growth rate in lined ponds

Our first growth study documented individual growth rates at normal density in 11

million gallon lined ponds13 over two13 years13 This is the standard13 grow-shy‐out process for

razorbacks13 at Bubbling Ponds We monitored growth of fish for a variety13 of sizes and13 the13

37

13

amount of time in a pond during the growing season These13 data give a snapshot of growth13

rates13 at the13 facility13 and13 provide13 the basis for comparisons throughout our study

Growth rate13 in an unlined pond

In addition13 to 6 ponds lined with heavy plastic13 sheeting13 Bubbling Ponds Fish13

Hatchery maintains two narrow and deep (same dimensions as lined ponds13 Figure13 4)13 and13

three large13 shallow unlined ponds These earthen13 ponds typically have vegetation and

associated aquatic invertebrates that may better simulate natural environments by

providing cover and improved food diversity or quality Therefore these unlined ponds

may be expected to produce higher growth rates and potentially improved survival that is

more similar to growth rates observed in more natural grow-shy‐out facilities13 Historically13 the13

large13 shallow13 ponds have produced very large fish when13 utilized at low13 fish density13 The

narrow13 deep earthen13 ponds are13 used to grow13 fry13 at high density in their first13 year of life

The major downside to unlined ponds is the difficulty in harvesting fish where a lined

pond might take 8-shy‐1013 people13 a half13 day13 to13 harvest13 lined13 ponds13 require13 intensive13 weeding13

to allow seines to be pulled and therefore require many more personnel-shy‐hours13 In addition13

to harvest challenges the shallow earthen ponds tend to suffer from13 dissolved oxygen

crashes during the summer Unlined ponds also may maintain higher13 populations13 of non-shy‐

target species such as bluegill sunfish mosquito fish and bullfrog tadpoles We measured

growth rates of suckers in a large shallow earthen pond for comparison to growth in lined

ponds13

Figure13 4 Lined13 and13 earthen ponds13 of similar dimensions (approx 1000000 gallons first

and second panels) and a large13 shallow13 earthen13 pond (third panel)

38

13

Effect of sorting on growth

Razorback13 suckers13 are13 currently13 sorted13 after their first13 year of growth13 They are13

typically removed from13 one of the13 upper earthen13 ponds and13 split into13 two13 lined13 ponds for

subsequent grow-shy‐out13 The larger13 fish (gt approximately 140 mm) are placed into one pond

and the smaller individuals in another It is possible that the larger fish were more

aggressive or adept13 at taking food so this sorting process is intended to allow smaller fish

to improve their growth rate

Effect of Ich on razorback sucker growth rates

We13 evaluated13 growth13 rates13 of razorback sucker13 in the13 presence13 and absence of the

ectoparasite13 Ich (Ichthiopthirus multifiliis) Ich outbreaks can occur in wild populations13 but

hatcheries13 have13 proven excellent locations13 for Ich because13 of very high fish densities13 which13

facilitate13 the13 transfer13 of Ich13 between13 fish This common fish parasite causes direct mortality13

to razorback13 suckers as well13 as secondary bacterial13 infections13

The open spring and13 ditch13 which13 provides water to the Bubbling13 Ponds Hatchery

has long13 been infested with mosquitofish (Gambusia affinis) that harbor13 the13 Ich parasite13

and allow13 it13 to enter the hatchery with incoming13 water13 The solution13 to13 the13 Ich problem13

was to remove the mosquitofish host using13 Rotenone Razorback13 sucker growth13 rates were13

then tracked in13 the absence of this parasite for 4 months and compared with growth rates

after Ich returned to the pond and from13 previous years

Methods

Razorback growth rate in lined ponds

On May 14 2008 141 razorback suckers were tagged with 12 mm PIT tags (1342

kHz) and placed in Pond 3 (approximately 1100000 gallons13 Figure13 4)13 at Bubbling13 Ponds

Fish Hatchery Fifty-shy‐three of these tags were recovered two months later when a large

Ichthyophthirius multifilis (Ich) outbreak killed many fish in the pond On October 15 2008

an additional13 145 PIT tagged13 fish were13 also placed into Pond13 3 On13 May13 14 2009 Pond13 3

was harvested and a total13 of 141 PIT tagged fish were recovered13 Of the tagged fish13 26 fish

had13 been13 in the13 pond since May13 of 2008 (378 days13 o growth) and 115 had been13 in13 the

39

13 40

pond since October13 15 2008 (211 days13 of growth) Numbers of fish in Pond 3 after the Ich

outbreak and for the majority of the period of growth were between 3 000 and 4000 fish

A Hobotempreg temperature13 logger13 was13 also13 installed13 in Pond 3 one meter below the water

surface13 near13 the13 outflow and13 recorded water temperature every 3 hours to allow analysis

of the effects of water temperature on growth rate (Figure13 5) This Hobotemp data is

representative of other pond temperatures throughout this study

In a second experiment 210 adult13 razorback suckers13 were13 PIT tagged13 on13 May 14

2009 and13 placed13 into13 Pond13 3 upper to13 evaluate13 growth13 rates13 of larger13 razorback suckers13 at

Bubbling13 Ponds Hatchery13 under current13 rearing13 conditions13 Size of these fish at tagging13

was (mean = 285 mm range = 205 ndash 396 mm) These fish remained in the pond for 257

days and were harvested on Jan 25 2010 to provide information on growth rates of larger

razorback suckers13 under13 current rearing conditions

Figure 513 Temperatures (degC) inrearing pond at BubblingPonds Hatchery from July toSept 2009 (top graph)13 andfrom Nov to Dec 2009 (Lowergraph) Temperaturesrecorded with a Hobotempregremote data logger13 every 3hours

13

Growth rate13 in an unlined pond

To document razorback sucker growth in earthen ponds we introduced13 225 tagged13

razorback suckers13 into13 Pond13 1 lower13 (Figure 4) in February 3 2010 Additional tagged fish

from13 other studies were added to the pond throughout the growing season and the density

of 1 lower reached a maximum13 of nearly 7000 fish in early summer 2010 Density was

reduced to approximately 6000 fish by capturing fish with hoop nets on June 3 2010 54 of

these fish were tagged fish and returned to 1 lower after being weighed and measured The

pond was harvested on January13 2713 2011 and a total13 of 254 tagged fish out13 of 4296 fish

total were removed from13 the pond The pond was harvested on January 27 2011 (358 days13

of growth) and the tagged fish were weighed and measured Total number of razorbacks in

the pond at harvest13 was 4296

Effect of sorting practices on growth rates

On March 1113 200913 Pond13 5 upper was13 harvested13 and13 split into13 two13 separate13 groups

Two hundred of the smaller fish (average size = 122 mm TL) were PIT tagged and placed

into13 Pond13 7 upper and13 200 of the13 larger13 fish (average = 160 mm TL) were PIT tagged and

placed int Pond13 8 upper Density13 in Pond13 7 was13 4500 fish and13 in Pond13 8 there13 were13 6500

fish These ponds were then harvested after 1 year and growth rates were compared to

give information on the effects of current sorting practices Hobotempreg temperature

loggers were installed in13 Ponds 7 and13 8 during13 the13 grow-shy‐out period with13 water13

temperature recorded every 2 hours13 (Figure13 6)

Effect of Ich on razorback sucker growth rates

Bubbling Ponds spring was treated with Rotenone (CFT Legumine 5) at a

concentration of 2 ppm13 to remove all mosquitofish from13 the spring The treatment

consisted of two treatments 6 hours in duration on two consecutive days (April 12 -shy‐ 13)

using13 drip13 stations13 and13 backpack sprayers13 followed13 by13 an13 additional 6 hours13 of

detoxification using sodium13 permanganate Although 12 mosquitofish were captured in the

spring pond the week following the treatments subsequent minnow trapping (20 traps

checked13 daily13 for 3 weeks) did not capture any additional fish until August 11 2010 when

41

13

juvenile mosquitofish were again detected in the spring pond Minnow traps have

subsequently been set daily with several hundred individuals removed To evaluate if Ich

was also again present in the spring we captured 15 mosquitofish from13 the spring pond on

three separate days and placed them13 in an aquaria at 25 degC with 5 longfin dace known to be

free of Ich These fish were monitored for 2 weeks with no signs of Ich developing This

indicates that even though mosquitofish have returned to the spring pond the parasite is no

longer present13 although how13 long13 this condition13 will13 persist13 is unknown13

On May 1113 201013 200 juvenile razorback13 suckers were harvested out13 of Pond 5

upper (2009 year Class from13 Dexter National Fish Hatchery) and were PIT tagged and

placed into Pond 8 to evaluate if growth rates at bubbling ponds hatchery have improved

following the renovation of the spring and the removal of the Ich parasite Unfortunately13

on Sept13 8 2010 Ich was13 again13 detected13 in Pond 8 and the pond was immediately seined

and 74 tagged fish were measured to obtain growth information for the 4-shy‐month period

during13 which13 the13 pond13 was13 Ich-shy‐free13

Figure13 6 Temperatures (degC) in rearingponds 7 and 8 at Bubbling Ponds Hatchery13 from March 2009 ndash March 201013 pond 7(top13 graph)13 and13 pond 8 (Lower13 graph)13 Temperatures recorded with a Hobotempregremote data logger every 3 hours

42

13

Results

Growth in Lined Ponds

Razorback suckers13 that had been13 in13 Pond 8 upper for the13 entire13 year13 grew an13

average of 0263 mmday (789 mmmonth) and razorback suckers that had been in the

pond for 7 months (Oct -shy‐ May) grew13 on13 average of 028 mmday (843 mmmonth) (Figure13

7) These growth13 rates13 did not significantly13 differ Fish density13 in Pond 3 during13 the13

majority of the growth period was13 00032 ndash 00036 fishgallon13 Additionally no13 significant

differences in growth rate were observed between fish smaller than 210 mm TL and fish

larger than 210 mm TL when all recaptured fish were combined

We also measured the growth rate of very large fish in a lined pond On Jan13 2513 201013

156 adult fish with PIT tags were recovered from13 Pond 3 upper13 These fish were13 in the13

pond for 257 days and experienced an average13 growth13 rate13 of 024mmday or 73

mmmonth (Figure13 7)13 This growth13 rate13 is slightly13 lower13 than13 the13 average13 growth13 rate13

observed13 at Bubbling13 Ponds Hatchery in other studies (0275 mmday 825 mmmonth)

but may not be biologically meaningful We would expect larger13 fish to13 have13 reduced

growth rates according to a typical Von Bertalanfy growth model (Bertalanffy 1957) but it

appears that13 over the size range we evaluated (300 -shy‐ 450 mm TL) growth rates have not

slowed significantly compared to that of smaller13 fish grown at Bubbling Ponds13 Hatchery

Growth13 of razorback suckers13 is known13 to13 slow as13 fish reach13 larger13 sizes but it appears13 this13

reduced growth rate may not really start to be biologically meaningful at Bubbling Ponds

Hatchery13 until razorback suckers13 exceed 450 mm TL

Growth in unlined ponds

Growth13 rates13 for the13 fish recaptured13 during13 the Pond 1 lower13 thinning13 (120 days13 in

the pond) was 024 plusmn 003 mmday (729 plusmn 090 mmmonth) (Figure13 8)13 Fish13 that were13 in

the pond for nearly the entire year grew13 an13 average13 of 024 plusmn 001 mmday (726 plusmn 027

mmmonth) These growth rates are surprisingly the lowest measured growth rates for

any part of our study and differ significantly from13 every other measured growth rate

except very large13 fish (Figure13 9)13 Separating13 out13 large fish that13 were in13 the pond for the

entire year makes no difference fish that were added to the pond at TL lt300 mm grew

43

13

Gro

wth

Rat

e (m

md

ay)

020

026

032

0244 plusmn 001 mmday (733 plusmn 028 mmmonth) and and those with TL gt= 300 mm at the

start of the experiment grew 022 plusmn 003 mmday (651 plusmn 101 mmmonth)

Razorback Growth Rates in Lined Ponds

Figure 7 Growth ofrazorback suckers in(mmday plusmn standard error)in Pond 8 upper in 2008-shy‐2009 An ANOVA did notdetect any significantdifferences

7 Months Full Year 300+ mm fish

Effects of sorting on growth

One hundred and seventy five tagged razorback suckers were recovered from13 Pond

8 upper13 on March13 24 2010 (378 days13 of growth)13 These were13 the13 larger sorted13 fish (gt140

mm TL) that came out of Pond13 5 on March13 11 2009 One13 hundred and13 twenty13 two13 tagged13

razorback suckers were also recovered from13 Pond13 7 upper on March13 31 2010 (385 days13 of

growth)13 These were13 the13 smaller sorted13 fish (lt140 mm TL) that came out of Pond13 5 on

March 1113 200913 No significant differences in growth rate (mmday) were observed among

larger fish in Pond 8 and smaller fish in Pond 7 (pgt005 ANOVA) (Figure 10)13 indicating

that13 sorting may have helped to offset the original slower growth trajectory of the smaller

fish Temperatures of Ponds 7 and 8 upper remained similar throughout the year13 (Figure

5)

44

13

13

13

Gro

wth

Rat

e (m

md

ay)

Gro

wth

Rat

e (m

md

ay)

020

026

032

020

026

032

Razorback Growth in an Unlined Pond

Figure 8 Growth of razorbacksuckers (mmday plusmn standard error) in Pond 1 lower (an unlined pond)in 2010-shy‐2011 An ANOVA did notdetect any significant differences

6 Months 12 Months lt 300 mm Fish 300+ mm Fish Growth Growth

Lined vs Earthen Ponds 1 year of growth

Figure 9 Growth of razorbacksuckers (mmday plusmn standard error) in lined and unlined ponds A t-shy‐test13 did not detect a significantdifference

Lined Pond Unlined Pond 1 Yr Growth 1 Yr Growth

45

13

Effect of Sorting G

row

th R

ate

(mm

day

) G

row

th R

ate

(mm

day

)

032

020

026

032

020

026

Smaller Fish Larger Fish

Effect of Ich

Figure 10 Average growthof razorback suckers(mmday plusmn standard error)that were size-shy‐sorted intosmall fish (pond 7) and largefish (pond 8) populations At-shy‐test did not detect asignificant difference

Figure 11 Average growth ofrazorback suckers (mmday plusmnstandard error) after Ich wasremovd from the hatcheryrsquos springand after Ich was again detected inthe pond The growth rate withoutIch is significantly higher than boththe rate after Ich and the ourstudyrsquos average annual growth ratein lined ponds (ANOVA p =00003)

Growth without Ich Growth With Ich Average Annual 4 months 4 months Growth Rate

46

13

Effect of Ich on razorback sucker growth rates

Seventy-shy‐four13 tagged13 razorback suckers13 were13 recovered from13 Pond 8 on September

15 2010 These fish had13 been13 in the pond for 4 months and experienced a growth rate of

032 mmday or 97 mmmonth (Figure13 11)13 This growth13 rate13 is significantly higher (p =

005 two sample t-shy‐test) than the mean growth rate for the same group13 of tagged fish after

Ich detection (022 mmday or 65 mmmonth) and significantly higher than any other

individual growth13 rates13 observed13 to13 date13 at Bubbling13 Ponds Hatchery13 (Figure13 11)13 If this13

growth13 rate13 were13 extended throughout13 the entire13 year13 fish on average from13 Ich-shy‐free13 ponds13

would be 16 mm longer than fish from13 ponds infested with Ich Studies conducted at

Bubbling Ponds hatchery in 2008 (Ward 2008) did not reveal any effects of the treatment

chemicals on razorback sucker growth rates so it13 is likely that13 the parasite outbreaks

themselves are causing reducing growth rates rather than the chemicals used to treat the

parasites13

Conclusions

Our results suggest that under typical hatchery operations (maximizing number of

fish produced)13 the growth13 rate13 of razorback13 suckers13 is relatively13 consistent at Bubbling13

Ponds hatchery13 at 02-shy‐03 mmday (6-shy‐9 mmmonth)13 but is lower than growth13 rates13 at

other13 facilities (02 ndash 18 mmday Ward et al 2007)13 This growth13 rate13 has13 been13 constant in

both lined and unlined ponds and at all fish densities we were able to measure To achieve13

growth13 rates13 substantially higher than this will likely require13 significant changes in rearing

practices that may not be practical in order to reach numerical production13 goals

Temperature is a key variable in fish growth but seasonal growth patterns

described13 above13 (Figure13 5) demonstrate that water temperatures are high enough in

winter to maintain razorback growth Differences in water temperature by season

currently13 do not fluctuate more than 10degC at Bubbling Ponds because of the continuous

supply of water flowing through each pond (approx 225 gallonsmin) These high water

flows appear to keep pond temperatures within the thermal preference13 for razorback

suckers13 (1213 -shy‐ 28 degC Bulkley and Pimentel 1983) throughout the entire year with

temperatures rarely dropping13 below 16deg13 C (Figures 513 6)13

47

13

Fish density is another key variable in fish growth and though the number of fish in

a pond during our study ranged from13 3000 to 700013 fish we13 did not find any13 correlation13

between13 density and growth rate13 This might yield two conclusions First13 razorback

growth13 may be changed equally13 by13 densities13 at the13 hatchery13 (ie13 a density13 of 3000 fish in a

pond is as stressful13 for razorbacks as a density13 of 7000 fish) An alternative is that other

factors13 such as disease outbreaks have13 stronger13 control over fish growth13 than13 density13

Fish density13 would13 have13 to13 be13 experimentally manipulated to test13 this13 and hatchery

operations (producing the maximum13 number of fish) prevented our manipulating density13

in ponds for this13 work The trouble with manipulating density demonstrates the difficulties

associated with changing13 hatchery13 practices experimenting with density would have

prevented BPH from13 meeting13 production13 goals Given that the stocking of smaller

razorbacks has met with very little success perhaps BPH goals could be changed from13

producing 12000 fish at 300+ mm per year to a smaller number of very large fish each

year Growing13 fewer13 larger13 fish could potentially be accomplished in the same time frame

as more smaller fish but a better understanding of how density alters growth rate would

be required to be confident13 of this

The very slow growth13 in the13 earthen13 unlined13 Pond 1 lower13 was very surprising We13

had13 anticipated13 that the13 diversified diet13 cover and13 other13 habitat features13 provided by13

unlined ponds would yield dramatically increased growth rates However these traits were

not enough to offset high fish densities and in fact the unlined pond in our study13 suffered

mortality to bring densities down to that observed normally in lined ponds

Our data13 suggest13 that razorbacks13 sucker13 growth13 rates13 are13 higher in lined13 ponds13

However we13 think the reasons13 for the13 very slow growth we observed13 in the13 unlined13 pond13

in our study13 is instead13 linked13 to13 the13 usage13 of Pond 1 lower13 during13 the13 study13 rather13 than13

intrinsic13 slow growth13 in earthen13 ponds First the pond was at extremely high density for at

least part of the study The volume of Pond 1 lower has not been estimated but hatchery

managers suggest 1500-shy‐2000 fish is an appropriate number of individuals so this pond

was at a very high density for much of the experiment Second dissolved oxygen is often

very low in the13 large13 earthen13 ponds during the heat of summer much lower than that of

lined ponds This will both limit the number of fish that can survive in the pond and almost

certainly13 increases stress13 of these13 fish potentially13 reducing growth13 The DO crashes also13

48

13

limit the amount of feed hatchery managers can give fish in these ponds sometimes for

days or weeks at a time which further reduces growth during warm13 weather

Our data13 suggests that13 growth rates at the Bubbling13 Ponds Fish Hatchery are likely

as high as possible given13 the pond densities required to meet production goals and the Ich-shy‐

infested water that feeds the facility Sorting practices are successful in helping as many

fish as possible reach stocking length as fast as possible Unlined ponds may be able to

grow13 large13 fish at low13 densities13 but whatever factors allow13 for that13 growth are not13 able to

overcome high fish density The removal of invasive13 fis that act as13 a host for the13 parasite13

Ich fish from13 the Bubbling13 Ponds spring13 allowed the highest13 growth rate at 032 mmday13

(96 mmmonth) but that growth rate decreased again as Ich re-shy‐infested13 the13 hatchery13

Consistently13 achieving13 growth13 rates13 as high or substantially13 higher than13 this13 will likely13

require13 significant changes in rearing practices that may not be practical in order to13 reach13

numerical production13 goals

Two major changes that might result in higher growth rates are substantially

reducing fish density and modifying the way spring water is delivered to the facility (via

either repeated chemical treatments or enclosed concrete water diversions) to eliminate

Ich from13 the hatchery source water Other potential changes not address by our work

include13 flow-shy‐training razorbacks much previous literature including MSCP-shy‐funded13 work

on razorback suckers13 suggests13 that fish growing13 in flowing water will grow13 faster than fish

in still water (Jorgensen and Jobling 1994) Furthermore there are a wide variety of

potential benefits associated with growing13 fish13 in flowing13 water in addition13 to increased

growth13 rates13 (Davidson13 199713 Castro13 et al13 2011) Another option13 for increasing13 growth13

rates13 include13 changing to13 intensive13 culture13 in large circular13 tanks

Finally given that the stocking of smaller razorbacks has met with very little

success13 perhaps13 BPH13 goals13 could13 be13 changed from13 producing 12000 fish at 300+ mm per

year to a smaller number of very large fish each year Growing fewer larger fish could

potentially be accomplished in the same time frame as more smaller fish but a better

understanding13 of how density13 alters growth13 rate13 would13 be13 required to13 be13 confident of this

49

13

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower13 Colorado13 River Multi-shy‐Species13

Conservation Program13 (LCRMSCP) under Work Task C10 We13 thank Ty Wolters13 Tom13

Burke13 and Eric13 Volkman for their support of this research and Frank Agygos and Dave

Billingsly13 of the Bubbling13 Ponds Fish Hatchery13 for their willingness to participate in13 this

research13 and13 for their technical assistance We also thank the LCRMSCP fish group from13

Boulder City13 NV for their assistance with harvesting13 ponds and tagging13 fish13

50

13

Literature13 CitedAnders P J 1998 Conservation aquaculture and endangered species can objective science13

prevail13 over risk13 anxiety Fisheries 23(11) 28-shy‐31

Anderson R O and R M Nuemann 1996 Length weight and associated structural indicesPages 447 ndash 482 in B R Murphy13 and D13 W Willis13 editors13 Fisheries techniques13 2ndedtion American Fisheries13 Society13 Bethesda13 Maryland

Bain M B J T Finn and H E Brooks 1988 Streamflow regulation and fish communitystructure13 Ecology13 69382-shy‐392

Bays J H Zarbock R Whitman and T Murphy 2005 Conceptual design and managementof native13 fish refugia on the13 lower13 Colorado13 River In13 CL Spring13 and13 S Leoneditors Proceedings of two symposia Restoring native fish to the lower ColoradoRiver13 interactions13 of native and non-shy‐native13 fishes 13ndash1413 July13 1999 Las13 Vegas13 Nevada13 Restoring13 natural function within a modified riverine environment thelower Colorado River13 8ndash913 July13 1998 U S Fish and13 Wildlife13 Service Southwestern13 Region Albuquerque New Mexico Pages 167-shy‐177

Bertalanffy L Von 1957 Quantitative laws in metabolism13 and growth13 Q Rev Biology 32217 ndash 231

Bingham T B Scheer and C McAda 2003 Propagation facilities in Grand Valley (24 RoadHatchery Horsethief13 Ponds and13 grow-shy‐out ponds) for captive13 rearing13 ofendangered13 fishes for the13 upper13 Colorado13 River basin13 Colorado River RecoveryProgram FY2003 annual project report13 US Fish and13 Wildlife13 Service GrandJunction13 4pp

Birchell G J and K Christopherson 2004 Survival growth and recruitment of larval andjuvenile razorback13 sucker (Xyrauchen texanus) introduced13 into13 floodplain13 depressions13 of the13 Green River Utah13 Final report13 Upper13 Colorado13 RiverEndangered Fish Recovery Program13 Project No C-shy‐6RZ Publication Number 04-shy‐1513 Utah13 Division of Wildlife13 Resources Salt Lake13 City13 Utah13 67 pages

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Brett J R 1979 Environmental Factors and growth pages 599-shy‐67513 InW S Hoar13 D13 J13 Randall and J R Brett (eds) Fish Physiology Volume 8 Bioenergetics and GrowthAcademic Press New York

Brooks J E 1986 Annual reintroduction and monitoring report for razorback suckerXyrauchen texanus in the Gila River Basin Arizona 1985 US Fish and WildlifeService13 Offices of Endangered13 Species and Fishery13 Resources Albuquerque 23 pp

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Brunson13 R E and K D13 Christopherson13 200513 Larval13 razorback13 sucker and bonytailsurvival and13 growth13 in the13 presence13 of nonnative13 fish in the13 Baeser13 floodplainwetland of the middle Green River Final report prepared for Upper13 Colorado RiverBasin Endangered Fish Recovery Program Project No C-shy‐6-shy‐rz-shy‐bt Publication13 No 05-shy‐26 Utah13 Division of Wildlife13 Resources13 Vernal13 32 pp

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Burke13 T13 199513 Rearing13 wild razorback13 sucker larvae in13 lake-shy‐side13 backwaters13 LakeMohave ArizonaNevada Proceedings of the Desert Fishes Council 2635

Busacker G P I R Adelman and E M Goolish13 199013 Growth13 Pages 363 ndash 387 in C BSchreck and p B Moyle editors Methods for fish biology American FisheriesSociety Bethesda Maryland

Castro V B Grisdale-shy‐Helland S J Helland T Kristensen S M Jorgensen J Helgrud13 GClaireaux A P Farrell A Krasnov and H Takle 2011 Aerobic training stimulatesgrowth and promotes disease resistance in Atlantic salmon (Salmo salar)Comparative Biochemistry and Physiology -shy‐ Part A Molecular amp IntegrativePhysiology13 160(2) 278-shy‐290

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Marsh13 P13 C13 1987a13 Digestive tract13 contents13 of adult razorback suckers13 in Lake13 MohaveArizona-shy‐Nevada Transactions of the American Fisheries Society 116117-shy‐119

Marsh P C 1987b Native fishes at Buenos Aires National Wildlife Refuge and ArizonaState University Research Park Arizona opportunities for management researchand public13 education13 on13 endangered species13 Proceedings of the Desert13 FishesCouncil 1967-shy‐78

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USFWS 2004 Management plan for the big-shy‐river13 fishes of the13 lower13 Colorado13 river basinamendment and supplement to the bonytail humpback chub Coloradopikeminnow and razorback sucker recovery plans

USFWS13 2005 Station13 profile13 of the13 Dexter13 National Fish Hatchery13 and Technology CenterUS Fish and Wildlife13 Service Dexter

Valdez R A P G Mangan R Smith and B Nilson 1982 Upper Colorado River fisheriesinvestigations13 inW H Miller J J Valentine D L Archer H M Tyus R A Valdezand L13 Kaeding13 editors13 Colorado River Fishery13 Project13 Part 2 Field13 investigations13 US Bureau of Reclamation Salt Lake City Utah

WBNFH 2004 Culture methods of the endangered razorback sucker Xyrauchen texanusUS Fish and Wildlife13 Service Willow Beach National Fish Hatchery13 8 pp

Ward D 2008 Effects of disease treatments on growth of razorback sucker ReportSubmitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 Inpartial fulfillment of work task C10 agreement number 06FG30039

Ward13 D13 M Childs and W Persons 2007 Factors13 affecting13 growth13 of razorback sucker13 (Xyrauchen texanus) in captivity Literature review and knowledge assessmentReport Submitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 In partial fulfillment of work task C10 agreement number 06FG30039

57

Appendices

Appendix 1 Survey Questions Survey of Razorback Sucker Culture in the

Southwestern United States

The enclosed survey is being distributed by the Arizona Game and Fish Department to razorback sucker culture facilities throughout

the Southwestern United States The purpose of this survey is to consolidate information regarding culture of this species so that

appropriate facility improvements can be considered for Bubbling Ponds Hatchery in Arizona Specifically we wish to increase

growth rate and production efficiency at the hatchery Information gathered in this survey will be summarized in a final report to US

Bureau of Reclamation in Boulder City NV and disseminated to all facilities that participate in the survey A workshop to discuss

the findings of this study as well as to share general information concerning razorback sucker culture will be organized by the

Arizona Game and Fish Department at the conclusion of this study and all participants will be invited

Thank you for taking the time to fill out this survey Please contact Mike Childs if you have questions or would like to discuss the

survey

Mike Childs

mchildssedonanet

(928) 639-1346

(928) 634-1279

Facility_____________________________________ Date___________________

Contact Phone _____________________________

ContactPerson_______________________________

Contact Email _______________________________

1 Water quality ranges at this culture facility

Season

Spring (Mar-May) Summer (Jun-Aug) Fall (Sept-Nov) Winter (Dec-Feb)

Temperature (C)

PH

DO (mgL)

PO4 (mgL)

TDS (mgL)

Hardness (mgL)

CaCO3

Pathogens

37

13

growth13 rates of fish13 reared for four months without Ich present (031 mmday 92 mmmonth)were significantly higher than the following 8 months of growth for those same fish (022mmday 65 mmmonth) This disease-shy‐free growth rate is in fact faster than any13 otherprevious growth rates observed at the hatchery in our study

We conclude that growth rates at the Bubbling Ponds Fish Hatchery are likely as highas possible given the pond densities required to13 meet production goals and the Ich-shy‐infestedwater13 that feeds the facility Sorting practices are successful in helping as many fish as possiblereach stocking length as fast as possible Unlined ponds may be able to grow large fish at lowdensities but whatever factors allow for that growth13 are not able13 to overcome13 high fish densityThus the large lower ponds at Bubbling Ponds may be better utilized via renovation to13 deepenand line them

Disease is the most important factor limiting growth as may be expected to be the caseat many13 hatcheries While the spring renovation was not13 a complete success13 the dramaticreduction of fish populations in that habitat was enough to dramatically13 reduce13 the13 occurrenceof Ich at the hatchery13 Such open spring13 systems feeding a hatchery are a misfortune that canbe expected to transmit disease so we suggest that renovating the spring again to combat13 IchImproved techniques to divert water from13 the springs and more throuough treatment ofstream-shy‐side vegetation may improve the success of chemical treatment Successful renovationwould likely both improve growth rates and reduce chemical costs associated with treating Ichoutbreaks Even13 if complete renovation13 is impossible or impractical an13 effort to reduceinvasive fish density in the springs13 which act a vector for the parasite(and thereby reduce thelikelihood of13 Ich being transmitted into ponds) may still13 show dramatic improvements

36

13

Introduction

Conservation efforts13 for razorback sucker13 (Xyrauchen texanus)13 currently13 depend on

captive rearing and stocking programs Low survival of stocked razorback suckers (Brooks

1986 Marsh13 and13 Brooks13 1989 Marsh13 and13 Pacey13 2005) has13 caused13 target sizes for stocked13

fish to steadily increase in efforts to reduce predation mortality13 (Marsh13 et al13 2005

Schooley and Marsh 2007) Rearing fish to larger sizes at hatcheries comes with increased

costs and creates the need to evaluate husbandry and rearing practices that may affect fish

growth13 We evaluated growth13 rates13 of individual razorback suckers13 in ponds13 at Bubbling

Ponds Fish Hatchery13 using Passive Integrated13 Transponder (PIT) tags13 to13 obtain13 precise

growth information for individual fish so that valid comparisons of growth rates as related

to rearing practices can be made

Due to the critical nature of the razorback sucker stocking program we did not

design experimental studies that would require major rearrangement and potentially

reduce production of hatchery operations Instead our studies used normal variation in

production techniques and practices to isolate factors that may modify growth rates

Though this methodology dramatically limits replication and may limit our ability to

directly13 attribute13 differences in growth13 rates13 to13 the13 variables13 we13 investigate13 we13 were13 able13

to accomplish research goals without altering hatchery operations or impacting

production

From13 2009 through 2011 we conducted a series of observational13 growth13 studies to

determine growth rates of individual razorbacks at Bubbling Ponds The first set of

experiments included13 identifying13 growth13 rates13 in lined13 and13 unlined13 ponds determining

growth13 rates13 of fish at different13 sizes13 in13 relation13 to sorting13 practices and monitoring

razorback growth rates after removing the source of the ectoparasite13 Ich (Ichthiopthirus

multifiliis) from13 the hatchery water source13

Razorback growth rate in lined ponds

Our first growth study documented individual growth rates at normal density in 11

million gallon lined ponds13 over two13 years13 This is the standard13 grow-shy‐out process for

razorbacks13 at Bubbling Ponds We monitored growth of fish for a variety13 of sizes and13 the13

37

13

amount of time in a pond during the growing season These13 data give a snapshot of growth13

rates13 at the13 facility13 and13 provide13 the basis for comparisons throughout our study

Growth rate13 in an unlined pond

In addition13 to 6 ponds lined with heavy plastic13 sheeting13 Bubbling Ponds Fish13

Hatchery maintains two narrow and deep (same dimensions as lined ponds13 Figure13 4)13 and13

three large13 shallow unlined ponds These earthen13 ponds typically have vegetation and

associated aquatic invertebrates that may better simulate natural environments by

providing cover and improved food diversity or quality Therefore these unlined ponds

may be expected to produce higher growth rates and potentially improved survival that is

more similar to growth rates observed in more natural grow-shy‐out facilities13 Historically13 the13

large13 shallow13 ponds have produced very large fish when13 utilized at low13 fish density13 The

narrow13 deep earthen13 ponds are13 used to grow13 fry13 at high density in their first13 year of life

The major downside to unlined ponds is the difficulty in harvesting fish where a lined

pond might take 8-shy‐1013 people13 a half13 day13 to13 harvest13 lined13 ponds13 require13 intensive13 weeding13

to allow seines to be pulled and therefore require many more personnel-shy‐hours13 In addition13

to harvest challenges the shallow earthen ponds tend to suffer from13 dissolved oxygen

crashes during the summer Unlined ponds also may maintain higher13 populations13 of non-shy‐

target species such as bluegill sunfish mosquito fish and bullfrog tadpoles We measured

growth rates of suckers in a large shallow earthen pond for comparison to growth in lined

ponds13

Figure13 4 Lined13 and13 earthen ponds13 of similar dimensions (approx 1000000 gallons first

and second panels) and a large13 shallow13 earthen13 pond (third panel)

38

13

Effect of sorting on growth

Razorback13 suckers13 are13 currently13 sorted13 after their first13 year of growth13 They are13

typically removed from13 one of the13 upper earthen13 ponds and13 split into13 two13 lined13 ponds for

subsequent grow-shy‐out13 The larger13 fish (gt approximately 140 mm) are placed into one pond

and the smaller individuals in another It is possible that the larger fish were more

aggressive or adept13 at taking food so this sorting process is intended to allow smaller fish

to improve their growth rate

Effect of Ich on razorback sucker growth rates

We13 evaluated13 growth13 rates13 of razorback sucker13 in the13 presence13 and absence of the

ectoparasite13 Ich (Ichthiopthirus multifiliis) Ich outbreaks can occur in wild populations13 but

hatcheries13 have13 proven excellent locations13 for Ich because13 of very high fish densities13 which13

facilitate13 the13 transfer13 of Ich13 between13 fish This common fish parasite causes direct mortality13

to razorback13 suckers as well13 as secondary bacterial13 infections13

The open spring and13 ditch13 which13 provides water to the Bubbling13 Ponds Hatchery

has long13 been infested with mosquitofish (Gambusia affinis) that harbor13 the13 Ich parasite13

and allow13 it13 to enter the hatchery with incoming13 water13 The solution13 to13 the13 Ich problem13

was to remove the mosquitofish host using13 Rotenone Razorback13 sucker growth13 rates were13

then tracked in13 the absence of this parasite for 4 months and compared with growth rates

after Ich returned to the pond and from13 previous years

Methods

Razorback growth rate in lined ponds

On May 14 2008 141 razorback suckers were tagged with 12 mm PIT tags (1342

kHz) and placed in Pond 3 (approximately 1100000 gallons13 Figure13 4)13 at Bubbling13 Ponds

Fish Hatchery Fifty-shy‐three of these tags were recovered two months later when a large

Ichthyophthirius multifilis (Ich) outbreak killed many fish in the pond On October 15 2008

an additional13 145 PIT tagged13 fish were13 also placed into Pond13 3 On13 May13 14 2009 Pond13 3

was harvested and a total13 of 141 PIT tagged fish were recovered13 Of the tagged fish13 26 fish

had13 been13 in the13 pond since May13 of 2008 (378 days13 o growth) and 115 had been13 in13 the

39

13 40

pond since October13 15 2008 (211 days13 of growth) Numbers of fish in Pond 3 after the Ich

outbreak and for the majority of the period of growth were between 3 000 and 4000 fish

A Hobotempreg temperature13 logger13 was13 also13 installed13 in Pond 3 one meter below the water

surface13 near13 the13 outflow and13 recorded water temperature every 3 hours to allow analysis

of the effects of water temperature on growth rate (Figure13 5) This Hobotemp data is

representative of other pond temperatures throughout this study

In a second experiment 210 adult13 razorback suckers13 were13 PIT tagged13 on13 May 14

2009 and13 placed13 into13 Pond13 3 upper to13 evaluate13 growth13 rates13 of larger13 razorback suckers13 at

Bubbling13 Ponds Hatchery13 under current13 rearing13 conditions13 Size of these fish at tagging13

was (mean = 285 mm range = 205 ndash 396 mm) These fish remained in the pond for 257

days and were harvested on Jan 25 2010 to provide information on growth rates of larger

razorback suckers13 under13 current rearing conditions

Figure 513 Temperatures (degC) inrearing pond at BubblingPonds Hatchery from July toSept 2009 (top graph)13 andfrom Nov to Dec 2009 (Lowergraph) Temperaturesrecorded with a Hobotempregremote data logger13 every 3hours

13

Growth rate13 in an unlined pond

To document razorback sucker growth in earthen ponds we introduced13 225 tagged13

razorback suckers13 into13 Pond13 1 lower13 (Figure 4) in February 3 2010 Additional tagged fish

from13 other studies were added to the pond throughout the growing season and the density

of 1 lower reached a maximum13 of nearly 7000 fish in early summer 2010 Density was

reduced to approximately 6000 fish by capturing fish with hoop nets on June 3 2010 54 of

these fish were tagged fish and returned to 1 lower after being weighed and measured The

pond was harvested on January13 2713 2011 and a total13 of 254 tagged fish out13 of 4296 fish

total were removed from13 the pond The pond was harvested on January 27 2011 (358 days13

of growth) and the tagged fish were weighed and measured Total number of razorbacks in

the pond at harvest13 was 4296

Effect of sorting practices on growth rates

On March 1113 200913 Pond13 5 upper was13 harvested13 and13 split into13 two13 separate13 groups

Two hundred of the smaller fish (average size = 122 mm TL) were PIT tagged and placed

into13 Pond13 7 upper and13 200 of the13 larger13 fish (average = 160 mm TL) were PIT tagged and

placed int Pond13 8 upper Density13 in Pond13 7 was13 4500 fish and13 in Pond13 8 there13 were13 6500

fish These ponds were then harvested after 1 year and growth rates were compared to

give information on the effects of current sorting practices Hobotempreg temperature

loggers were installed in13 Ponds 7 and13 8 during13 the13 grow-shy‐out period with13 water13

temperature recorded every 2 hours13 (Figure13 6)

Effect of Ich on razorback sucker growth rates

Bubbling Ponds spring was treated with Rotenone (CFT Legumine 5) at a

concentration of 2 ppm13 to remove all mosquitofish from13 the spring The treatment

consisted of two treatments 6 hours in duration on two consecutive days (April 12 -shy‐ 13)

using13 drip13 stations13 and13 backpack sprayers13 followed13 by13 an13 additional 6 hours13 of

detoxification using sodium13 permanganate Although 12 mosquitofish were captured in the

spring pond the week following the treatments subsequent minnow trapping (20 traps

checked13 daily13 for 3 weeks) did not capture any additional fish until August 11 2010 when

41

13

juvenile mosquitofish were again detected in the spring pond Minnow traps have

subsequently been set daily with several hundred individuals removed To evaluate if Ich

was also again present in the spring we captured 15 mosquitofish from13 the spring pond on

three separate days and placed them13 in an aquaria at 25 degC with 5 longfin dace known to be

free of Ich These fish were monitored for 2 weeks with no signs of Ich developing This

indicates that even though mosquitofish have returned to the spring pond the parasite is no

longer present13 although how13 long13 this condition13 will13 persist13 is unknown13

On May 1113 201013 200 juvenile razorback13 suckers were harvested out13 of Pond 5

upper (2009 year Class from13 Dexter National Fish Hatchery) and were PIT tagged and

placed into Pond 8 to evaluate if growth rates at bubbling ponds hatchery have improved

following the renovation of the spring and the removal of the Ich parasite Unfortunately13

on Sept13 8 2010 Ich was13 again13 detected13 in Pond 8 and the pond was immediately seined

and 74 tagged fish were measured to obtain growth information for the 4-shy‐month period

during13 which13 the13 pond13 was13 Ich-shy‐free13

Figure13 6 Temperatures (degC) in rearingponds 7 and 8 at Bubbling Ponds Hatchery13 from March 2009 ndash March 201013 pond 7(top13 graph)13 and13 pond 8 (Lower13 graph)13 Temperatures recorded with a Hobotempregremote data logger every 3 hours

42

13

Results

Growth in Lined Ponds

Razorback suckers13 that had been13 in13 Pond 8 upper for the13 entire13 year13 grew an13

average of 0263 mmday (789 mmmonth) and razorback suckers that had been in the

pond for 7 months (Oct -shy‐ May) grew13 on13 average of 028 mmday (843 mmmonth) (Figure13

7) These growth13 rates13 did not significantly13 differ Fish density13 in Pond 3 during13 the13

majority of the growth period was13 00032 ndash 00036 fishgallon13 Additionally no13 significant

differences in growth rate were observed between fish smaller than 210 mm TL and fish

larger than 210 mm TL when all recaptured fish were combined

We also measured the growth rate of very large fish in a lined pond On Jan13 2513 201013

156 adult fish with PIT tags were recovered from13 Pond 3 upper13 These fish were13 in the13

pond for 257 days and experienced an average13 growth13 rate13 of 024mmday or 73

mmmonth (Figure13 7)13 This growth13 rate13 is slightly13 lower13 than13 the13 average13 growth13 rate13

observed13 at Bubbling13 Ponds Hatchery in other studies (0275 mmday 825 mmmonth)

but may not be biologically meaningful We would expect larger13 fish to13 have13 reduced

growth rates according to a typical Von Bertalanfy growth model (Bertalanffy 1957) but it

appears that13 over the size range we evaluated (300 -shy‐ 450 mm TL) growth rates have not

slowed significantly compared to that of smaller13 fish grown at Bubbling Ponds13 Hatchery

Growth13 of razorback suckers13 is known13 to13 slow as13 fish reach13 larger13 sizes but it appears13 this13

reduced growth rate may not really start to be biologically meaningful at Bubbling Ponds

Hatchery13 until razorback suckers13 exceed 450 mm TL

Growth in unlined ponds

Growth13 rates13 for the13 fish recaptured13 during13 the Pond 1 lower13 thinning13 (120 days13 in

the pond) was 024 plusmn 003 mmday (729 plusmn 090 mmmonth) (Figure13 8)13 Fish13 that were13 in

the pond for nearly the entire year grew13 an13 average13 of 024 plusmn 001 mmday (726 plusmn 027

mmmonth) These growth rates are surprisingly the lowest measured growth rates for

any part of our study and differ significantly from13 every other measured growth rate

except very large13 fish (Figure13 9)13 Separating13 out13 large fish that13 were in13 the pond for the

entire year makes no difference fish that were added to the pond at TL lt300 mm grew

43

13

Gro

wth

Rat

e (m

md

ay)

020

026

032

0244 plusmn 001 mmday (733 plusmn 028 mmmonth) and and those with TL gt= 300 mm at the

start of the experiment grew 022 plusmn 003 mmday (651 plusmn 101 mmmonth)

Razorback Growth Rates in Lined Ponds

Figure 7 Growth ofrazorback suckers in(mmday plusmn standard error)in Pond 8 upper in 2008-shy‐2009 An ANOVA did notdetect any significantdifferences

7 Months Full Year 300+ mm fish

Effects of sorting on growth

One hundred and seventy five tagged razorback suckers were recovered from13 Pond

8 upper13 on March13 24 2010 (378 days13 of growth)13 These were13 the13 larger sorted13 fish (gt140

mm TL) that came out of Pond13 5 on March13 11 2009 One13 hundred and13 twenty13 two13 tagged13

razorback suckers were also recovered from13 Pond13 7 upper on March13 31 2010 (385 days13 of

growth)13 These were13 the13 smaller sorted13 fish (lt140 mm TL) that came out of Pond13 5 on

March 1113 200913 No significant differences in growth rate (mmday) were observed among

larger fish in Pond 8 and smaller fish in Pond 7 (pgt005 ANOVA) (Figure 10)13 indicating

that13 sorting may have helped to offset the original slower growth trajectory of the smaller

fish Temperatures of Ponds 7 and 8 upper remained similar throughout the year13 (Figure

5)

44

13

13

13

Gro

wth

Rat

e (m

md

ay)

Gro

wth

Rat

e (m

md

ay)

020

026

032

020

026

032

Razorback Growth in an Unlined Pond

Figure 8 Growth of razorbacksuckers (mmday plusmn standard error) in Pond 1 lower (an unlined pond)in 2010-shy‐2011 An ANOVA did notdetect any significant differences

6 Months 12 Months lt 300 mm Fish 300+ mm Fish Growth Growth

Lined vs Earthen Ponds 1 year of growth

Figure 9 Growth of razorbacksuckers (mmday plusmn standard error) in lined and unlined ponds A t-shy‐test13 did not detect a significantdifference

Lined Pond Unlined Pond 1 Yr Growth 1 Yr Growth

45

13

Effect of Sorting G

row

th R

ate

(mm

day

) G

row

th R

ate

(mm

day

)

032

020

026

032

020

026

Smaller Fish Larger Fish

Effect of Ich

Figure 10 Average growthof razorback suckers(mmday plusmn standard error)that were size-shy‐sorted intosmall fish (pond 7) and largefish (pond 8) populations At-shy‐test did not detect asignificant difference

Figure 11 Average growth ofrazorback suckers (mmday plusmnstandard error) after Ich wasremovd from the hatcheryrsquos springand after Ich was again detected inthe pond The growth rate withoutIch is significantly higher than boththe rate after Ich and the ourstudyrsquos average annual growth ratein lined ponds (ANOVA p =00003)

Growth without Ich Growth With Ich Average Annual 4 months 4 months Growth Rate

46

13

Effect of Ich on razorback sucker growth rates

Seventy-shy‐four13 tagged13 razorback suckers13 were13 recovered from13 Pond 8 on September

15 2010 These fish had13 been13 in the pond for 4 months and experienced a growth rate of

032 mmday or 97 mmmonth (Figure13 11)13 This growth13 rate13 is significantly higher (p =

005 two sample t-shy‐test) than the mean growth rate for the same group13 of tagged fish after

Ich detection (022 mmday or 65 mmmonth) and significantly higher than any other

individual growth13 rates13 observed13 to13 date13 at Bubbling13 Ponds Hatchery13 (Figure13 11)13 If this13

growth13 rate13 were13 extended throughout13 the entire13 year13 fish on average from13 Ich-shy‐free13 ponds13

would be 16 mm longer than fish from13 ponds infested with Ich Studies conducted at

Bubbling Ponds hatchery in 2008 (Ward 2008) did not reveal any effects of the treatment

chemicals on razorback sucker growth rates so it13 is likely that13 the parasite outbreaks

themselves are causing reducing growth rates rather than the chemicals used to treat the

parasites13

Conclusions

Our results suggest that under typical hatchery operations (maximizing number of

fish produced)13 the growth13 rate13 of razorback13 suckers13 is relatively13 consistent at Bubbling13

Ponds hatchery13 at 02-shy‐03 mmday (6-shy‐9 mmmonth)13 but is lower than growth13 rates13 at

other13 facilities (02 ndash 18 mmday Ward et al 2007)13 This growth13 rate13 has13 been13 constant in

both lined and unlined ponds and at all fish densities we were able to measure To achieve13

growth13 rates13 substantially higher than this will likely require13 significant changes in rearing

practices that may not be practical in order to reach numerical production13 goals

Temperature is a key variable in fish growth but seasonal growth patterns

described13 above13 (Figure13 5) demonstrate that water temperatures are high enough in

winter to maintain razorback growth Differences in water temperature by season

currently13 do not fluctuate more than 10degC at Bubbling Ponds because of the continuous

supply of water flowing through each pond (approx 225 gallonsmin) These high water

flows appear to keep pond temperatures within the thermal preference13 for razorback

suckers13 (1213 -shy‐ 28 degC Bulkley and Pimentel 1983) throughout the entire year with

temperatures rarely dropping13 below 16deg13 C (Figures 513 6)13

47

13

Fish density is another key variable in fish growth and though the number of fish in

a pond during our study ranged from13 3000 to 700013 fish we13 did not find any13 correlation13

between13 density and growth rate13 This might yield two conclusions First13 razorback

growth13 may be changed equally13 by13 densities13 at the13 hatchery13 (ie13 a density13 of 3000 fish in a

pond is as stressful13 for razorbacks as a density13 of 7000 fish) An alternative is that other

factors13 such as disease outbreaks have13 stronger13 control over fish growth13 than13 density13

Fish density13 would13 have13 to13 be13 experimentally manipulated to test13 this13 and hatchery

operations (producing the maximum13 number of fish) prevented our manipulating density13

in ponds for this13 work The trouble with manipulating density demonstrates the difficulties

associated with changing13 hatchery13 practices experimenting with density would have

prevented BPH from13 meeting13 production13 goals Given that the stocking of smaller

razorbacks has met with very little success perhaps BPH goals could be changed from13

producing 12000 fish at 300+ mm per year to a smaller number of very large fish each

year Growing13 fewer13 larger13 fish could potentially be accomplished in the same time frame

as more smaller fish but a better understanding of how density alters growth rate would

be required to be confident13 of this

The very slow growth13 in the13 earthen13 unlined13 Pond 1 lower13 was very surprising We13

had13 anticipated13 that the13 diversified diet13 cover and13 other13 habitat features13 provided by13

unlined ponds would yield dramatically increased growth rates However these traits were

not enough to offset high fish densities and in fact the unlined pond in our study13 suffered

mortality to bring densities down to that observed normally in lined ponds

Our data13 suggest13 that razorbacks13 sucker13 growth13 rates13 are13 higher in lined13 ponds13

However we13 think the reasons13 for the13 very slow growth we observed13 in the13 unlined13 pond13

in our study13 is instead13 linked13 to13 the13 usage13 of Pond 1 lower13 during13 the13 study13 rather13 than13

intrinsic13 slow growth13 in earthen13 ponds First the pond was at extremely high density for at

least part of the study The volume of Pond 1 lower has not been estimated but hatchery

managers suggest 1500-shy‐2000 fish is an appropriate number of individuals so this pond

was at a very high density for much of the experiment Second dissolved oxygen is often

very low in the13 large13 earthen13 ponds during the heat of summer much lower than that of

lined ponds This will both limit the number of fish that can survive in the pond and almost

certainly13 increases stress13 of these13 fish potentially13 reducing growth13 The DO crashes also13

48

13

limit the amount of feed hatchery managers can give fish in these ponds sometimes for

days or weeks at a time which further reduces growth during warm13 weather

Our data13 suggests that13 growth rates at the Bubbling13 Ponds Fish Hatchery are likely

as high as possible given13 the pond densities required to meet production goals and the Ich-shy‐

infested water that feeds the facility Sorting practices are successful in helping as many

fish as possible reach stocking length as fast as possible Unlined ponds may be able to

grow13 large13 fish at low13 densities13 but whatever factors allow13 for that13 growth are not13 able to

overcome high fish density The removal of invasive13 fis that act as13 a host for the13 parasite13

Ich fish from13 the Bubbling13 Ponds spring13 allowed the highest13 growth rate at 032 mmday13

(96 mmmonth) but that growth rate decreased again as Ich re-shy‐infested13 the13 hatchery13

Consistently13 achieving13 growth13 rates13 as high or substantially13 higher than13 this13 will likely13

require13 significant changes in rearing practices that may not be practical in order to13 reach13

numerical production13 goals

Two major changes that might result in higher growth rates are substantially

reducing fish density and modifying the way spring water is delivered to the facility (via

either repeated chemical treatments or enclosed concrete water diversions) to eliminate

Ich from13 the hatchery source water Other potential changes not address by our work

include13 flow-shy‐training razorbacks much previous literature including MSCP-shy‐funded13 work

on razorback suckers13 suggests13 that fish growing13 in flowing water will grow13 faster than fish

in still water (Jorgensen and Jobling 1994) Furthermore there are a wide variety of

potential benefits associated with growing13 fish13 in flowing13 water in addition13 to increased

growth13 rates13 (Davidson13 199713 Castro13 et al13 2011) Another option13 for increasing13 growth13

rates13 include13 changing to13 intensive13 culture13 in large circular13 tanks

Finally given that the stocking of smaller razorbacks has met with very little

success13 perhaps13 BPH13 goals13 could13 be13 changed from13 producing 12000 fish at 300+ mm per

year to a smaller number of very large fish each year Growing fewer larger fish could

potentially be accomplished in the same time frame as more smaller fish but a better

understanding13 of how density13 alters growth13 rate13 would13 be13 required to13 be13 confident of this

49

13

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower13 Colorado13 River Multi-shy‐Species13

Conservation Program13 (LCRMSCP) under Work Task C10 We13 thank Ty Wolters13 Tom13

Burke13 and Eric13 Volkman for their support of this research and Frank Agygos and Dave

Billingsly13 of the Bubbling13 Ponds Fish Hatchery13 for their willingness to participate in13 this

research13 and13 for their technical assistance We also thank the LCRMSCP fish group from13

Boulder City13 NV for their assistance with harvesting13 ponds and tagging13 fish13

50

13

Literature13 CitedAnders P J 1998 Conservation aquaculture and endangered species can objective science13

prevail13 over risk13 anxiety Fisheries 23(11) 28-shy‐31

Anderson R O and R M Nuemann 1996 Length weight and associated structural indicesPages 447 ndash 482 in B R Murphy13 and D13 W Willis13 editors13 Fisheries techniques13 2ndedtion American Fisheries13 Society13 Bethesda13 Maryland

Bain M B J T Finn and H E Brooks 1988 Streamflow regulation and fish communitystructure13 Ecology13 69382-shy‐392

Bays J H Zarbock R Whitman and T Murphy 2005 Conceptual design and managementof native13 fish refugia on the13 lower13 Colorado13 River In13 CL Spring13 and13 S Leoneditors Proceedings of two symposia Restoring native fish to the lower ColoradoRiver13 interactions13 of native and non-shy‐native13 fishes 13ndash1413 July13 1999 Las13 Vegas13 Nevada13 Restoring13 natural function within a modified riverine environment thelower Colorado River13 8ndash913 July13 1998 U S Fish and13 Wildlife13 Service Southwestern13 Region Albuquerque New Mexico Pages 167-shy‐177

Bertalanffy L Von 1957 Quantitative laws in metabolism13 and growth13 Q Rev Biology 32217 ndash 231

Bingham T B Scheer and C McAda 2003 Propagation facilities in Grand Valley (24 RoadHatchery Horsethief13 Ponds and13 grow-shy‐out ponds) for captive13 rearing13 ofendangered13 fishes for the13 upper13 Colorado13 River basin13 Colorado River RecoveryProgram FY2003 annual project report13 US Fish and13 Wildlife13 Service GrandJunction13 4pp

Birchell G J and K Christopherson 2004 Survival growth and recruitment of larval andjuvenile razorback13 sucker (Xyrauchen texanus) introduced13 into13 floodplain13 depressions13 of the13 Green River Utah13 Final report13 Upper13 Colorado13 RiverEndangered Fish Recovery Program13 Project No C-shy‐6RZ Publication Number 04-shy‐1513 Utah13 Division of Wildlife13 Resources Salt Lake13 City13 Utah13 67 pages

Brannon E L 1993 The perpetual oversight of hatchery programs Fishery Research 1819-shy‐27

Brett J R 1979 Environmental Factors and growth pages 599-shy‐67513 InW S Hoar13 D13 J13 Randall and J R Brett (eds) Fish Physiology Volume 8 Bioenergetics and GrowthAcademic Press New York

Brooks J E 1986 Annual reintroduction and monitoring report for razorback suckerXyrauchen texanus in the Gila River Basin Arizona 1985 US Fish and WildlifeService13 Offices of Endangered13 Species and Fishery13 Resources Albuquerque 23 pp

51

13

Brunson13 R E and K D13 Christopherson13 200513 Larval13 razorback13 sucker and bonytailsurvival and13 growth13 in the13 presence13 of nonnative13 fish in the13 Baeser13 floodplainwetland of the middle Green River Final report prepared for Upper13 Colorado RiverBasin Endangered Fish Recovery Program Project No C-shy‐6-shy‐rz-shy‐bt Publication13 No 05-shy‐26 Utah13 Division of Wildlife13 Resources13 Vernal13 32 pp

Bulkley R V and R Pimentel 1983 Temperature preference and avoidance by adultrazorback suckers Transactions of the American Fisheries Society 112601-shy‐607

Burke13 T13 199513 Rearing13 wild razorback13 sucker larvae in13 lake-shy‐side13 backwaters13 LakeMohave ArizonaNevada Proceedings of the Desert Fishes Council 2635

Busacker G P I R Adelman and E M Goolish13 199013 Growth13 Pages 363 ndash 387 in C BSchreck and p B Moyle editors Methods for fish biology American FisheriesSociety Bethesda Maryland

Castro V B Grisdale-shy‐Helland S J Helland T Kristensen S M Jorgensen J Helgrud13 GClaireaux A P Farrell A Krasnov and H Takle 2011 Aerobic training stimulatesgrowth and promotes disease resistance in Atlantic salmon (Salmo salar)Comparative Biochemistry and Physiology -shy‐ Part A Molecular amp IntegrativePhysiology13 160(2) 278-shy‐290

Czapla T E 2002 Facilities plan for the production of endangered fishes to meet statestocking13 plans13 as13 part of the13 Upper13 Colorado13 River Endangered13 Fish RecoveryProgram Upper Colorado River Basin Recovery Implementation Program US Fishand Wildlife Service13 Denver13 9 pp

Davidson W 1997 The effects13 of exercise13 training on teleost fish a review of recentliterature Comput Biochem Physiol 117A67ndash75

Figiel Jr C R 2005 Annual report fiscal year 2004 Willow Beach National13 Fish HatcheryUS Fish and Wildlife13 Service Willow Beach 17 pp

Figiel Jr C R M E Ulibarri G Carmichael J Seals and J N Hanson 2005 Intensive13 fish13 culture of warmwater native fishes at a coldwater fish hatchery Pages 164-shy‐16613 inProceedings of two symposia restoring native fish to the lower Colorado13 River13 interaction13 of native13 and13 non-shy‐native13 fishes July13 13-shy‐1413 1999 Las Vegas Nevada USFish and Wildlife Service Southwest Region Albuquerque New Mexico

Gerking13 S D 1978 Ecology of freshwater fish13 production13 Halstead Press13 New13 York

Gustafson W and Q Bradwisch 2000 Wahweap operation and maintenance -shy‐-shy‐ UtahColorado River Recovery Program FY 2000 annual project report Project No 29cUtah13 Division of Wildlife13 Resources Page AZ 3pp

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Hamman R L 1985 Induced spawning of hatchery-shy‐reared13 razorback sucker ProgressivFish Culturist 47(3) 187-shy‐189

Hanson J N 1996 Annual report fiscal year 1996 Willow Beach National Fish HatcheryUS Fish and Wildlife Service13 Willow Beach 9pp

Irving D S Seversen and M Montagne 2004 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2004 annual project13 report Report No 29b US Fish and13 Wildlife13 Service Vernal 3pp

Jorgensen E H and13 M Jobling 1994 Feeding and13 growth13 of exercised13 and13 unexercised13 juvenile Atlantic salmon in freshwater and performance after transfer to seawaterAquaculture International 2 154-shy‐164

Kaeding L R and D B Osmundson 198913 Colorado13 Squawfish13 and13 razorback sucker grow-shy‐out pond studies as part of conservation measures for the green mountain andRuedi reservoir water sales Final report for agreement number 6-shy‐AA-shy‐60-shy‐00150

Koebele13 B P13 198513 Growth and the size hierarchy effect an experimental assessment ofthree proposed mechanisms activity differences disproportional food acquisition13 pysiological stress Environmental Biology of Fishes 12 181-shy‐188

Kretschmann A E and L L Leslie 2006 Razorback sucker (Xyrauchen texanus) status13 reproduction and recruitment in Senator Wash Reservoir CA Final Report13 to USBurea of Reclamation Cooperative Agreement No 00-shy‐FG-shy‐34-shy‐ 0009 p 32 ArizonaGame and Fish Department Phoenix

Marsh13 P13 C13 1987a13 Digestive tract13 contents13 of adult razorback suckers13 in Lake13 MohaveArizona-shy‐Nevada Transactions of the American Fisheries Society 116117-shy‐119

Marsh P C 1987b Native fishes at Buenos Aires National Wildlife Refuge and ArizonaState University Research Park Arizona opportunities for management researchand public13 education13 on13 endangered species13 Proceedings of the Desert13 FishesCouncil 1967-shy‐78

Marsh P C 1994 Rearing native Colorado River fishes in golf course ponds Arizona StateUniversity Tempe 22 + pages

Marsh13 P13 C13 200013 Fish population13 status and evaluation13 in13 the Cibola13 High Levee PondFinal report agreement number 99-shy‐FG-shy‐30-shy‐00051 US Bureau of ReclamationBoulder City13 Nevada13 20 pages

Marsh P C and C A Pacey 1998 Growth of wild adult razorback suckers13 in Lake13 Mohave13 Arizona-shy‐Nevada13 Final report13 US Bureau of Reclamation Boulder City Nevada 25pages + appendices

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Marsh P C B R Kesner and C A Pacey 2005 Repatriation as s management strategy13 to13 conserve a critically13 imperiled fish species North American Journal of FisheriesManagement 25 547-shy‐556

Marsh P C and C A Pacey 2005 Immiscibility of native and non-shy‐native13 fishes Pages 59-shy‐63 inMJ13 Brouder13 CL13 Springer13 and CS13 Leon13 editors13 Proceedings of two13 symposia Restoring native fish to the lower Colorado River interactions of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 NV and13 Restoring natural13 function within a modified riverine environment the lower Colorado River13 July13 8-shy‐913 1998 Las Vegas NV US Fish and13 Wildlife13 Service Southwest Region AlbuquerqueNew Mexico

Marsh13 P13 C13 and J13 E Brooks13 198913 Predation13 by ictalurid catfishes as a deterrent13 toreestablishment of hatchery-shy‐reared13 razorback sucker The Southwestern Naturalist34188-shy‐195

Matthews R A 2005 Ichthyopthirus multifiliis Fouquet and Ichthyopthirosis infreshwater13 teleosts13 Pages13 159-shy‐218 in Advances in Parasitology volume 59 J RBaker R Muller D Rollinson (eds) Academic Press

McCarthy13 M S and W L Minckley 1987 Age estimation for razorback sucker (PiscesCatostomidae) from13 Lake Mohave Arizona and Nevada Journal of the Arizona-shy‐Nevada Academy of Science 2187-shy‐97

Minckley13 W L13 198313 Status of the razorback13 sucker13 Xyrauchen texanus (Abbot)13 in13 thelower Colorado River basin13 The Southwestern13 Naturalist13 28(2) 165-shy‐187

Minckley13 W L13 199113 Native fished of the Grand Canyon13 region an obituary13 Pages 124-shy‐177 in Colorado River ecology and dam13 management National Academy PressWashington13 DC

Minckley13 C13 O and M LaBarbara13 199913 Report13 on13 native fish grow-shy‐out facilities13 at Cibolaand Imperial National Wildlife Refuges 1993-shy‐199513 US Fish and13 Wildlife Service13 Parker Fishery Resources Office Parker Arizona

Modde13 T13 199613 Juvenile razorback sucker (Xyrauchen texanus) in a managed wetlandadjacent13 to the Green13 River13 Great13 Basin13 Naturalist13 56375-shy‐376

Modde T KP Burnham and E J Wick 1996 Population status of the razorback sucker13 inthe middle Green River (USA) Conservation13 biology 10 110-shy‐119

Modde13 T13 and G13 B Haines13 200513 Survival13 and growth of stocked razorback13 sucker andbonytail in multiple floodplain wetlands of the middle Green River under resetconditions13 Final report prepared for Upper Colorado13 River13 Basin RecoveryImplimentation Program US Fish and Wildlife Service Vernal 66 pp

54

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Modde T Z H Bowen and D C Kitcheyan 2005 Spatial and temporal use of a spawning13 site in the middle Green River by wild hatchery-shy‐reared13 razorback suckers13 Transactions of the American Fisheries Society 134937-shy‐944

Mueller13 G13 199213 The native fish work13 group13 -shy‐ a multiagency endeavor to improve thestatus of the razorback sucker in Lake Mohave AZ-shy‐NV13 Proceedings of the DesertFishes Council 2369

Mueller G 1995 A program13 for maintaining the razorback sucker in Lake MohaveAmerican Fisheries Society Symposium 15127-shy‐135

Mueller13 G13 200613 Ecology of the bonytail13 and razorback13 sucker and the role of offchannelhabitats13 in their13 recovery Scientific13 investigations13 report 2006-shy‐5065 US GeologicalSurvey13 Denver

Mueller G and E Wick 1998 Testing of golf course ponds at Page Arizona for suitability13 as grow-shy‐out facility for razorback sucker using surplus fish from13 Ouray NationalFish Hatchery National Park Service US Fish and13 Wildlife13 Service and UtahDivision of Wildlife13 Resources 28 pages

Mueller13 G13 and T13 Burke13 200513 Survival13 of young13 razorback13 sucker (Xyrauchen texanus) inrelation to13 stocking rates13 (fishha)13 and13 in the presence13 or absence13 of predatorcommunities in Lake Mohave Arizona-shy‐Nevada13 Pages13 155-shy‐16313 in Proceedings of two13 symposia restoring native fish to the lower Colorado River interaction13 of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 Nevada US Fish and Wildlife13 Service Southwest Region Albuquerque New Mexico

Mueller13 G13 J13 Carpenter13 and P13 C13 Marsh13 200413 Cibola13 High Levee Pond annual report 2004US Geological Survey Fort Collins13 Science Center13 Colorado13 and Arizona StateUniversity Tempe 23 pages

Nesler T P K Christopherson J M Hudson C W McAda F Pfeifer and T E Czapla 2003An integrated stocking plan for razorback sucker bonytail and Colorado13 pikeminnow for the Upper Colorado River Endangered Fish Recovery ProgramAddendum13 to State Stocking Plans Upper Colorado River Basin Recovery13 Implementation Program 12 pp

Papoulias13 D and W13 L Minckley13 1992 Effects13 of foo availability13 on survival and growth13 of larval razorback suckers13 in ponds Transactions of the American Fisheries Society121340-shy‐355

Paukert13 C P D L Ward13 P J Sponholtz13 and K13 D Hilwig13 Effects13 of repeated hoopnetting13 on bonytail chub13 Journal of Freshwater13 Ecology13 20(4) 649-shy‐653

Pfeifer F M13 C Baker13 and M13 Montagne13 199913 Propagation13 facilities13 in the13 Grand Valley13 (24 Road13 Hatchery13 Horsethief13 Ponds and13 grow-shy‐out ponds) for captive rearing of

55

13

endangered13 fishes for the13 Upper Colorado13 River Basin13 Colorado13 River Recovery13 Program FY 99 annual project report Project No 29a13 US Fish and Wildlife Service13 Grand13 Junction13 5pp

Pfeifer F S Seversen and M Montagne 2003 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2003 annual reportProject No 29b13 US Fish and Wildlife13 Service Vernal13 4pp

Rabago-shy‐Castro J L Sanchez13 J G Perez-shy‐Castaneda R and13 Gonzalez-shy‐Gonzlez A 2006Effects of the prophylactic use of Romet-shy‐3013 and13 copper13 sulfate13 on growth13 condition13 and feeding13 indicies in13 channel13 catfish (Ictalurus punctatus) Aquaculture 253 343-shy‐349

Reinitz GL L E Orme and F N Hitzel 1979 Variations of body compositio and growth13 among strains of rainbow trout Transactions of the American Fisheries Society 108204-shy‐207

Ruppert13 J13 B P B Holden13 and P D Abate 1999 Age estimation and growth of razorbacksucker13 Xyrauchen texanus in Lake13 Mead Nevada Proceedings13 of the Desert FishesCouncil 3040

Schnoor K D and J Logan 2002 Operation and maintenance of JW Mumma nativeaquatic13 species restoration facility Colorado Colorado River Recovery Program FY2002 annual project report13 Project No 29d Colorado13 Division of Wildlife Alamosa3pp

Salisbury13 L13 1998 Factors13 affecting razorback13 sucker growth13 in Lake13 Mohave backwaters13 MS Thesis13 Unviersity13 of Nevada13 Las13 Vegas

Schooley J13 D13 and P C13 Marsh13 2007 Stocking of endangerdd13 razorback13 suckers13 in thelower Colorado River Basin13 over three decades 1974-shy‐2004 North American Journalof Fisheries Management 27 43-shy‐51

Severson S H H M Tyus and G B Haines 1992 An evaluation of feeds for raisingrazorback sucker Xyrauchen texanus Journal of Applied Aquaculture 155-shy‐65

Toney D P 1974 Observations13 on the13 propagation13 and13 rearing13 of two13 endangered species13 in a hatchery environment Proceedings of the Annual Conference of the Western13 Association of State Game and Fish Commissions 54 252-shy‐259

Tyus H M13 1998 Razorback sucker13 (Xyrauchen texanus) recovery plan13 University13 ofColorado Center for Limnology Boulder13 76 pages

Tyus H M13 and13 S H Severson 1990 Growth13 and13 survival of larval razorback suckers fedfive formulated diets The Progressive Fish Culturist 52197-shy‐200

56

13

Ulibarri M E 2003 Annual report fiscal year 2001 Dexter National Fish Hatchery13 andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 26 pages

Ulibarri M E 2003 Annual report fiscal year 2002 Dexter National Fish Hatchery andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 59 pages

USBR 2006 Lower13 Colorado13 River Multi-shy‐Species Conservation Program final fishaugmentation plan Boulder City 19 pp

USFWS 2002 Razorback sucker (Xyraouchen texanus) recovery goals Amendment andsupplement to the Razorback Sucker Recovery Plan13 US Fish and Wildlife Service13 Region 6 Denver13 Colorado

USFWS 1999 Annual report 1999 Ouray National Fish Hatchery Vernal 25pp

USFWS 2004 Management plan for the big-shy‐river13 fishes of the13 lower13 Colorado13 river basinamendment and supplement to the bonytail humpback chub Coloradopikeminnow and razorback sucker recovery plans

USFWS13 2005 Station13 profile13 of the13 Dexter13 National Fish Hatchery13 and Technology CenterUS Fish and Wildlife13 Service Dexter

Valdez R A P G Mangan R Smith and B Nilson 1982 Upper Colorado River fisheriesinvestigations13 inW H Miller J J Valentine D L Archer H M Tyus R A Valdezand L13 Kaeding13 editors13 Colorado River Fishery13 Project13 Part 2 Field13 investigations13 US Bureau of Reclamation Salt Lake City Utah

WBNFH 2004 Culture methods of the endangered razorback sucker Xyrauchen texanusUS Fish and Wildlife13 Service Willow Beach National Fish Hatchery13 8 pp

Ward D 2008 Effects of disease treatments on growth of razorback sucker ReportSubmitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 Inpartial fulfillment of work task C10 agreement number 06FG30039

Ward13 D13 M Childs and W Persons 2007 Factors13 affecting13 growth13 of razorback sucker13 (Xyrauchen texanus) in captivity Literature review and knowledge assessmentReport Submitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 In partial fulfillment of work task C10 agreement number 06FG30039

57

Appendices

Appendix 1 Survey Questions Survey of Razorback Sucker Culture in the

Southwestern United States

The enclosed survey is being distributed by the Arizona Game and Fish Department to razorback sucker culture facilities throughout

the Southwestern United States The purpose of this survey is to consolidate information regarding culture of this species so that

appropriate facility improvements can be considered for Bubbling Ponds Hatchery in Arizona Specifically we wish to increase

growth rate and production efficiency at the hatchery Information gathered in this survey will be summarized in a final report to US

Bureau of Reclamation in Boulder City NV and disseminated to all facilities that participate in the survey A workshop to discuss

the findings of this study as well as to share general information concerning razorback sucker culture will be organized by the

Arizona Game and Fish Department at the conclusion of this study and all participants will be invited

Thank you for taking the time to fill out this survey Please contact Mike Childs if you have questions or would like to discuss the

survey

Mike Childs

mchildssedonanet

(928) 639-1346

(928) 634-1279

Facility_____________________________________ Date___________________

Contact Phone _____________________________

ContactPerson_______________________________

Contact Email _______________________________

1 Water quality ranges at this culture facility

Season

Spring (Mar-May) Summer (Jun-Aug) Fall (Sept-Nov) Winter (Dec-Feb)

Temperature (C)

PH

DO (mgL)

PO4 (mgL)

TDS (mgL)

Hardness (mgL)

CaCO3

Pathogens

37

13

Introduction

Conservation efforts13 for razorback sucker13 (Xyrauchen texanus)13 currently13 depend on

captive rearing and stocking programs Low survival of stocked razorback suckers (Brooks

1986 Marsh13 and13 Brooks13 1989 Marsh13 and13 Pacey13 2005) has13 caused13 target sizes for stocked13

fish to steadily increase in efforts to reduce predation mortality13 (Marsh13 et al13 2005

Schooley and Marsh 2007) Rearing fish to larger sizes at hatcheries comes with increased

costs and creates the need to evaluate husbandry and rearing practices that may affect fish

growth13 We evaluated growth13 rates13 of individual razorback suckers13 in ponds13 at Bubbling

Ponds Fish Hatchery13 using Passive Integrated13 Transponder (PIT) tags13 to13 obtain13 precise

growth information for individual fish so that valid comparisons of growth rates as related

to rearing practices can be made

Due to the critical nature of the razorback sucker stocking program we did not

design experimental studies that would require major rearrangement and potentially

reduce production of hatchery operations Instead our studies used normal variation in

production techniques and practices to isolate factors that may modify growth rates

Though this methodology dramatically limits replication and may limit our ability to

directly13 attribute13 differences in growth13 rates13 to13 the13 variables13 we13 investigate13 we13 were13 able13

to accomplish research goals without altering hatchery operations or impacting

production

From13 2009 through 2011 we conducted a series of observational13 growth13 studies to

determine growth rates of individual razorbacks at Bubbling Ponds The first set of

experiments included13 identifying13 growth13 rates13 in lined13 and13 unlined13 ponds determining

growth13 rates13 of fish at different13 sizes13 in13 relation13 to sorting13 practices and monitoring

razorback growth rates after removing the source of the ectoparasite13 Ich (Ichthiopthirus

multifiliis) from13 the hatchery water source13

Razorback growth rate in lined ponds

Our first growth study documented individual growth rates at normal density in 11

million gallon lined ponds13 over two13 years13 This is the standard13 grow-shy‐out process for

razorbacks13 at Bubbling Ponds We monitored growth of fish for a variety13 of sizes and13 the13

37

13

amount of time in a pond during the growing season These13 data give a snapshot of growth13

rates13 at the13 facility13 and13 provide13 the basis for comparisons throughout our study

Growth rate13 in an unlined pond

In addition13 to 6 ponds lined with heavy plastic13 sheeting13 Bubbling Ponds Fish13

Hatchery maintains two narrow and deep (same dimensions as lined ponds13 Figure13 4)13 and13

three large13 shallow unlined ponds These earthen13 ponds typically have vegetation and

associated aquatic invertebrates that may better simulate natural environments by

providing cover and improved food diversity or quality Therefore these unlined ponds

may be expected to produce higher growth rates and potentially improved survival that is

more similar to growth rates observed in more natural grow-shy‐out facilities13 Historically13 the13

large13 shallow13 ponds have produced very large fish when13 utilized at low13 fish density13 The

narrow13 deep earthen13 ponds are13 used to grow13 fry13 at high density in their first13 year of life

The major downside to unlined ponds is the difficulty in harvesting fish where a lined

pond might take 8-shy‐1013 people13 a half13 day13 to13 harvest13 lined13 ponds13 require13 intensive13 weeding13

to allow seines to be pulled and therefore require many more personnel-shy‐hours13 In addition13

to harvest challenges the shallow earthen ponds tend to suffer from13 dissolved oxygen

crashes during the summer Unlined ponds also may maintain higher13 populations13 of non-shy‐

target species such as bluegill sunfish mosquito fish and bullfrog tadpoles We measured

growth rates of suckers in a large shallow earthen pond for comparison to growth in lined

ponds13

Figure13 4 Lined13 and13 earthen ponds13 of similar dimensions (approx 1000000 gallons first

and second panels) and a large13 shallow13 earthen13 pond (third panel)

38

13

Effect of sorting on growth

Razorback13 suckers13 are13 currently13 sorted13 after their first13 year of growth13 They are13

typically removed from13 one of the13 upper earthen13 ponds and13 split into13 two13 lined13 ponds for

subsequent grow-shy‐out13 The larger13 fish (gt approximately 140 mm) are placed into one pond

and the smaller individuals in another It is possible that the larger fish were more

aggressive or adept13 at taking food so this sorting process is intended to allow smaller fish

to improve their growth rate

Effect of Ich on razorback sucker growth rates

We13 evaluated13 growth13 rates13 of razorback sucker13 in the13 presence13 and absence of the

ectoparasite13 Ich (Ichthiopthirus multifiliis) Ich outbreaks can occur in wild populations13 but

hatcheries13 have13 proven excellent locations13 for Ich because13 of very high fish densities13 which13

facilitate13 the13 transfer13 of Ich13 between13 fish This common fish parasite causes direct mortality13

to razorback13 suckers as well13 as secondary bacterial13 infections13

The open spring and13 ditch13 which13 provides water to the Bubbling13 Ponds Hatchery

has long13 been infested with mosquitofish (Gambusia affinis) that harbor13 the13 Ich parasite13

and allow13 it13 to enter the hatchery with incoming13 water13 The solution13 to13 the13 Ich problem13

was to remove the mosquitofish host using13 Rotenone Razorback13 sucker growth13 rates were13

then tracked in13 the absence of this parasite for 4 months and compared with growth rates

after Ich returned to the pond and from13 previous years

Methods

Razorback growth rate in lined ponds

On May 14 2008 141 razorback suckers were tagged with 12 mm PIT tags (1342

kHz) and placed in Pond 3 (approximately 1100000 gallons13 Figure13 4)13 at Bubbling13 Ponds

Fish Hatchery Fifty-shy‐three of these tags were recovered two months later when a large

Ichthyophthirius multifilis (Ich) outbreak killed many fish in the pond On October 15 2008

an additional13 145 PIT tagged13 fish were13 also placed into Pond13 3 On13 May13 14 2009 Pond13 3

was harvested and a total13 of 141 PIT tagged fish were recovered13 Of the tagged fish13 26 fish

had13 been13 in the13 pond since May13 of 2008 (378 days13 o growth) and 115 had been13 in13 the

39

13 40

pond since October13 15 2008 (211 days13 of growth) Numbers of fish in Pond 3 after the Ich

outbreak and for the majority of the period of growth were between 3 000 and 4000 fish

A Hobotempreg temperature13 logger13 was13 also13 installed13 in Pond 3 one meter below the water

surface13 near13 the13 outflow and13 recorded water temperature every 3 hours to allow analysis

of the effects of water temperature on growth rate (Figure13 5) This Hobotemp data is

representative of other pond temperatures throughout this study

In a second experiment 210 adult13 razorback suckers13 were13 PIT tagged13 on13 May 14

2009 and13 placed13 into13 Pond13 3 upper to13 evaluate13 growth13 rates13 of larger13 razorback suckers13 at

Bubbling13 Ponds Hatchery13 under current13 rearing13 conditions13 Size of these fish at tagging13

was (mean = 285 mm range = 205 ndash 396 mm) These fish remained in the pond for 257

days and were harvested on Jan 25 2010 to provide information on growth rates of larger

razorback suckers13 under13 current rearing conditions

Figure 513 Temperatures (degC) inrearing pond at BubblingPonds Hatchery from July toSept 2009 (top graph)13 andfrom Nov to Dec 2009 (Lowergraph) Temperaturesrecorded with a Hobotempregremote data logger13 every 3hours

13

Growth rate13 in an unlined pond

To document razorback sucker growth in earthen ponds we introduced13 225 tagged13

razorback suckers13 into13 Pond13 1 lower13 (Figure 4) in February 3 2010 Additional tagged fish

from13 other studies were added to the pond throughout the growing season and the density

of 1 lower reached a maximum13 of nearly 7000 fish in early summer 2010 Density was

reduced to approximately 6000 fish by capturing fish with hoop nets on June 3 2010 54 of

these fish were tagged fish and returned to 1 lower after being weighed and measured The

pond was harvested on January13 2713 2011 and a total13 of 254 tagged fish out13 of 4296 fish

total were removed from13 the pond The pond was harvested on January 27 2011 (358 days13

of growth) and the tagged fish were weighed and measured Total number of razorbacks in

the pond at harvest13 was 4296

Effect of sorting practices on growth rates

On March 1113 200913 Pond13 5 upper was13 harvested13 and13 split into13 two13 separate13 groups

Two hundred of the smaller fish (average size = 122 mm TL) were PIT tagged and placed

into13 Pond13 7 upper and13 200 of the13 larger13 fish (average = 160 mm TL) were PIT tagged and

placed int Pond13 8 upper Density13 in Pond13 7 was13 4500 fish and13 in Pond13 8 there13 were13 6500

fish These ponds were then harvested after 1 year and growth rates were compared to

give information on the effects of current sorting practices Hobotempreg temperature

loggers were installed in13 Ponds 7 and13 8 during13 the13 grow-shy‐out period with13 water13

temperature recorded every 2 hours13 (Figure13 6)

Effect of Ich on razorback sucker growth rates

Bubbling Ponds spring was treated with Rotenone (CFT Legumine 5) at a

concentration of 2 ppm13 to remove all mosquitofish from13 the spring The treatment

consisted of two treatments 6 hours in duration on two consecutive days (April 12 -shy‐ 13)

using13 drip13 stations13 and13 backpack sprayers13 followed13 by13 an13 additional 6 hours13 of

detoxification using sodium13 permanganate Although 12 mosquitofish were captured in the

spring pond the week following the treatments subsequent minnow trapping (20 traps

checked13 daily13 for 3 weeks) did not capture any additional fish until August 11 2010 when

41

13

juvenile mosquitofish were again detected in the spring pond Minnow traps have

subsequently been set daily with several hundred individuals removed To evaluate if Ich

was also again present in the spring we captured 15 mosquitofish from13 the spring pond on

three separate days and placed them13 in an aquaria at 25 degC with 5 longfin dace known to be

free of Ich These fish were monitored for 2 weeks with no signs of Ich developing This

indicates that even though mosquitofish have returned to the spring pond the parasite is no

longer present13 although how13 long13 this condition13 will13 persist13 is unknown13

On May 1113 201013 200 juvenile razorback13 suckers were harvested out13 of Pond 5

upper (2009 year Class from13 Dexter National Fish Hatchery) and were PIT tagged and

placed into Pond 8 to evaluate if growth rates at bubbling ponds hatchery have improved

following the renovation of the spring and the removal of the Ich parasite Unfortunately13

on Sept13 8 2010 Ich was13 again13 detected13 in Pond 8 and the pond was immediately seined

and 74 tagged fish were measured to obtain growth information for the 4-shy‐month period

during13 which13 the13 pond13 was13 Ich-shy‐free13

Figure13 6 Temperatures (degC) in rearingponds 7 and 8 at Bubbling Ponds Hatchery13 from March 2009 ndash March 201013 pond 7(top13 graph)13 and13 pond 8 (Lower13 graph)13 Temperatures recorded with a Hobotempregremote data logger every 3 hours

42

13

Results

Growth in Lined Ponds

Razorback suckers13 that had been13 in13 Pond 8 upper for the13 entire13 year13 grew an13

average of 0263 mmday (789 mmmonth) and razorback suckers that had been in the

pond for 7 months (Oct -shy‐ May) grew13 on13 average of 028 mmday (843 mmmonth) (Figure13

7) These growth13 rates13 did not significantly13 differ Fish density13 in Pond 3 during13 the13

majority of the growth period was13 00032 ndash 00036 fishgallon13 Additionally no13 significant

differences in growth rate were observed between fish smaller than 210 mm TL and fish

larger than 210 mm TL when all recaptured fish were combined

We also measured the growth rate of very large fish in a lined pond On Jan13 2513 201013

156 adult fish with PIT tags were recovered from13 Pond 3 upper13 These fish were13 in the13

pond for 257 days and experienced an average13 growth13 rate13 of 024mmday or 73

mmmonth (Figure13 7)13 This growth13 rate13 is slightly13 lower13 than13 the13 average13 growth13 rate13

observed13 at Bubbling13 Ponds Hatchery in other studies (0275 mmday 825 mmmonth)

but may not be biologically meaningful We would expect larger13 fish to13 have13 reduced

growth rates according to a typical Von Bertalanfy growth model (Bertalanffy 1957) but it

appears that13 over the size range we evaluated (300 -shy‐ 450 mm TL) growth rates have not

slowed significantly compared to that of smaller13 fish grown at Bubbling Ponds13 Hatchery

Growth13 of razorback suckers13 is known13 to13 slow as13 fish reach13 larger13 sizes but it appears13 this13

reduced growth rate may not really start to be biologically meaningful at Bubbling Ponds

Hatchery13 until razorback suckers13 exceed 450 mm TL

Growth in unlined ponds

Growth13 rates13 for the13 fish recaptured13 during13 the Pond 1 lower13 thinning13 (120 days13 in

the pond) was 024 plusmn 003 mmday (729 plusmn 090 mmmonth) (Figure13 8)13 Fish13 that were13 in

the pond for nearly the entire year grew13 an13 average13 of 024 plusmn 001 mmday (726 plusmn 027

mmmonth) These growth rates are surprisingly the lowest measured growth rates for

any part of our study and differ significantly from13 every other measured growth rate

except very large13 fish (Figure13 9)13 Separating13 out13 large fish that13 were in13 the pond for the

entire year makes no difference fish that were added to the pond at TL lt300 mm grew

43

13

Gro

wth

Rat

e (m

md

ay)

020

026

032

0244 plusmn 001 mmday (733 plusmn 028 mmmonth) and and those with TL gt= 300 mm at the

start of the experiment grew 022 plusmn 003 mmday (651 plusmn 101 mmmonth)

Razorback Growth Rates in Lined Ponds

Figure 7 Growth ofrazorback suckers in(mmday plusmn standard error)in Pond 8 upper in 2008-shy‐2009 An ANOVA did notdetect any significantdifferences

7 Months Full Year 300+ mm fish

Effects of sorting on growth

One hundred and seventy five tagged razorback suckers were recovered from13 Pond

8 upper13 on March13 24 2010 (378 days13 of growth)13 These were13 the13 larger sorted13 fish (gt140

mm TL) that came out of Pond13 5 on March13 11 2009 One13 hundred and13 twenty13 two13 tagged13

razorback suckers were also recovered from13 Pond13 7 upper on March13 31 2010 (385 days13 of

growth)13 These were13 the13 smaller sorted13 fish (lt140 mm TL) that came out of Pond13 5 on

March 1113 200913 No significant differences in growth rate (mmday) were observed among

larger fish in Pond 8 and smaller fish in Pond 7 (pgt005 ANOVA) (Figure 10)13 indicating

that13 sorting may have helped to offset the original slower growth trajectory of the smaller

fish Temperatures of Ponds 7 and 8 upper remained similar throughout the year13 (Figure

5)

44

13

13

13

Gro

wth

Rat

e (m

md

ay)

Gro

wth

Rat

e (m

md

ay)

020

026

032

020

026

032

Razorback Growth in an Unlined Pond

Figure 8 Growth of razorbacksuckers (mmday plusmn standard error) in Pond 1 lower (an unlined pond)in 2010-shy‐2011 An ANOVA did notdetect any significant differences

6 Months 12 Months lt 300 mm Fish 300+ mm Fish Growth Growth

Lined vs Earthen Ponds 1 year of growth

Figure 9 Growth of razorbacksuckers (mmday plusmn standard error) in lined and unlined ponds A t-shy‐test13 did not detect a significantdifference

Lined Pond Unlined Pond 1 Yr Growth 1 Yr Growth

45

13

Effect of Sorting G

row

th R

ate

(mm

day

) G

row

th R

ate

(mm

day

)

032

020

026

032

020

026

Smaller Fish Larger Fish

Effect of Ich

Figure 10 Average growthof razorback suckers(mmday plusmn standard error)that were size-shy‐sorted intosmall fish (pond 7) and largefish (pond 8) populations At-shy‐test did not detect asignificant difference

Figure 11 Average growth ofrazorback suckers (mmday plusmnstandard error) after Ich wasremovd from the hatcheryrsquos springand after Ich was again detected inthe pond The growth rate withoutIch is significantly higher than boththe rate after Ich and the ourstudyrsquos average annual growth ratein lined ponds (ANOVA p =00003)

Growth without Ich Growth With Ich Average Annual 4 months 4 months Growth Rate

46

13

Effect of Ich on razorback sucker growth rates

Seventy-shy‐four13 tagged13 razorback suckers13 were13 recovered from13 Pond 8 on September

15 2010 These fish had13 been13 in the pond for 4 months and experienced a growth rate of

032 mmday or 97 mmmonth (Figure13 11)13 This growth13 rate13 is significantly higher (p =

005 two sample t-shy‐test) than the mean growth rate for the same group13 of tagged fish after

Ich detection (022 mmday or 65 mmmonth) and significantly higher than any other

individual growth13 rates13 observed13 to13 date13 at Bubbling13 Ponds Hatchery13 (Figure13 11)13 If this13

growth13 rate13 were13 extended throughout13 the entire13 year13 fish on average from13 Ich-shy‐free13 ponds13

would be 16 mm longer than fish from13 ponds infested with Ich Studies conducted at

Bubbling Ponds hatchery in 2008 (Ward 2008) did not reveal any effects of the treatment

chemicals on razorback sucker growth rates so it13 is likely that13 the parasite outbreaks

themselves are causing reducing growth rates rather than the chemicals used to treat the

parasites13

Conclusions

Our results suggest that under typical hatchery operations (maximizing number of

fish produced)13 the growth13 rate13 of razorback13 suckers13 is relatively13 consistent at Bubbling13

Ponds hatchery13 at 02-shy‐03 mmday (6-shy‐9 mmmonth)13 but is lower than growth13 rates13 at

other13 facilities (02 ndash 18 mmday Ward et al 2007)13 This growth13 rate13 has13 been13 constant in

both lined and unlined ponds and at all fish densities we were able to measure To achieve13

growth13 rates13 substantially higher than this will likely require13 significant changes in rearing

practices that may not be practical in order to reach numerical production13 goals

Temperature is a key variable in fish growth but seasonal growth patterns

described13 above13 (Figure13 5) demonstrate that water temperatures are high enough in

winter to maintain razorback growth Differences in water temperature by season

currently13 do not fluctuate more than 10degC at Bubbling Ponds because of the continuous

supply of water flowing through each pond (approx 225 gallonsmin) These high water

flows appear to keep pond temperatures within the thermal preference13 for razorback

suckers13 (1213 -shy‐ 28 degC Bulkley and Pimentel 1983) throughout the entire year with

temperatures rarely dropping13 below 16deg13 C (Figures 513 6)13

47

13

Fish density is another key variable in fish growth and though the number of fish in

a pond during our study ranged from13 3000 to 700013 fish we13 did not find any13 correlation13

between13 density and growth rate13 This might yield two conclusions First13 razorback

growth13 may be changed equally13 by13 densities13 at the13 hatchery13 (ie13 a density13 of 3000 fish in a

pond is as stressful13 for razorbacks as a density13 of 7000 fish) An alternative is that other

factors13 such as disease outbreaks have13 stronger13 control over fish growth13 than13 density13

Fish density13 would13 have13 to13 be13 experimentally manipulated to test13 this13 and hatchery

operations (producing the maximum13 number of fish) prevented our manipulating density13

in ponds for this13 work The trouble with manipulating density demonstrates the difficulties

associated with changing13 hatchery13 practices experimenting with density would have

prevented BPH from13 meeting13 production13 goals Given that the stocking of smaller

razorbacks has met with very little success perhaps BPH goals could be changed from13

producing 12000 fish at 300+ mm per year to a smaller number of very large fish each

year Growing13 fewer13 larger13 fish could potentially be accomplished in the same time frame

as more smaller fish but a better understanding of how density alters growth rate would

be required to be confident13 of this

The very slow growth13 in the13 earthen13 unlined13 Pond 1 lower13 was very surprising We13

had13 anticipated13 that the13 diversified diet13 cover and13 other13 habitat features13 provided by13

unlined ponds would yield dramatically increased growth rates However these traits were

not enough to offset high fish densities and in fact the unlined pond in our study13 suffered

mortality to bring densities down to that observed normally in lined ponds

Our data13 suggest13 that razorbacks13 sucker13 growth13 rates13 are13 higher in lined13 ponds13

However we13 think the reasons13 for the13 very slow growth we observed13 in the13 unlined13 pond13

in our study13 is instead13 linked13 to13 the13 usage13 of Pond 1 lower13 during13 the13 study13 rather13 than13

intrinsic13 slow growth13 in earthen13 ponds First the pond was at extremely high density for at

least part of the study The volume of Pond 1 lower has not been estimated but hatchery

managers suggest 1500-shy‐2000 fish is an appropriate number of individuals so this pond

was at a very high density for much of the experiment Second dissolved oxygen is often

very low in the13 large13 earthen13 ponds during the heat of summer much lower than that of

lined ponds This will both limit the number of fish that can survive in the pond and almost

certainly13 increases stress13 of these13 fish potentially13 reducing growth13 The DO crashes also13

48

13

limit the amount of feed hatchery managers can give fish in these ponds sometimes for

days or weeks at a time which further reduces growth during warm13 weather

Our data13 suggests that13 growth rates at the Bubbling13 Ponds Fish Hatchery are likely

as high as possible given13 the pond densities required to meet production goals and the Ich-shy‐

infested water that feeds the facility Sorting practices are successful in helping as many

fish as possible reach stocking length as fast as possible Unlined ponds may be able to

grow13 large13 fish at low13 densities13 but whatever factors allow13 for that13 growth are not13 able to

overcome high fish density The removal of invasive13 fis that act as13 a host for the13 parasite13

Ich fish from13 the Bubbling13 Ponds spring13 allowed the highest13 growth rate at 032 mmday13

(96 mmmonth) but that growth rate decreased again as Ich re-shy‐infested13 the13 hatchery13

Consistently13 achieving13 growth13 rates13 as high or substantially13 higher than13 this13 will likely13

require13 significant changes in rearing practices that may not be practical in order to13 reach13

numerical production13 goals

Two major changes that might result in higher growth rates are substantially

reducing fish density and modifying the way spring water is delivered to the facility (via

either repeated chemical treatments or enclosed concrete water diversions) to eliminate

Ich from13 the hatchery source water Other potential changes not address by our work

include13 flow-shy‐training razorbacks much previous literature including MSCP-shy‐funded13 work

on razorback suckers13 suggests13 that fish growing13 in flowing water will grow13 faster than fish

in still water (Jorgensen and Jobling 1994) Furthermore there are a wide variety of

potential benefits associated with growing13 fish13 in flowing13 water in addition13 to increased

growth13 rates13 (Davidson13 199713 Castro13 et al13 2011) Another option13 for increasing13 growth13

rates13 include13 changing to13 intensive13 culture13 in large circular13 tanks

Finally given that the stocking of smaller razorbacks has met with very little

success13 perhaps13 BPH13 goals13 could13 be13 changed from13 producing 12000 fish at 300+ mm per

year to a smaller number of very large fish each year Growing fewer larger fish could

potentially be accomplished in the same time frame as more smaller fish but a better

understanding13 of how density13 alters growth13 rate13 would13 be13 required to13 be13 confident of this

49

13

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower13 Colorado13 River Multi-shy‐Species13

Conservation Program13 (LCRMSCP) under Work Task C10 We13 thank Ty Wolters13 Tom13

Burke13 and Eric13 Volkman for their support of this research and Frank Agygos and Dave

Billingsly13 of the Bubbling13 Ponds Fish Hatchery13 for their willingness to participate in13 this

research13 and13 for their technical assistance We also thank the LCRMSCP fish group from13

Boulder City13 NV for their assistance with harvesting13 ponds and tagging13 fish13

50

13

Literature13 CitedAnders P J 1998 Conservation aquaculture and endangered species can objective science13

prevail13 over risk13 anxiety Fisheries 23(11) 28-shy‐31

Anderson R O and R M Nuemann 1996 Length weight and associated structural indicesPages 447 ndash 482 in B R Murphy13 and D13 W Willis13 editors13 Fisheries techniques13 2ndedtion American Fisheries13 Society13 Bethesda13 Maryland

Bain M B J T Finn and H E Brooks 1988 Streamflow regulation and fish communitystructure13 Ecology13 69382-shy‐392

Bays J H Zarbock R Whitman and T Murphy 2005 Conceptual design and managementof native13 fish refugia on the13 lower13 Colorado13 River In13 CL Spring13 and13 S Leoneditors Proceedings of two symposia Restoring native fish to the lower ColoradoRiver13 interactions13 of native and non-shy‐native13 fishes 13ndash1413 July13 1999 Las13 Vegas13 Nevada13 Restoring13 natural function within a modified riverine environment thelower Colorado River13 8ndash913 July13 1998 U S Fish and13 Wildlife13 Service Southwestern13 Region Albuquerque New Mexico Pages 167-shy‐177

Bertalanffy L Von 1957 Quantitative laws in metabolism13 and growth13 Q Rev Biology 32217 ndash 231

Bingham T B Scheer and C McAda 2003 Propagation facilities in Grand Valley (24 RoadHatchery Horsethief13 Ponds and13 grow-shy‐out ponds) for captive13 rearing13 ofendangered13 fishes for the13 upper13 Colorado13 River basin13 Colorado River RecoveryProgram FY2003 annual project report13 US Fish and13 Wildlife13 Service GrandJunction13 4pp

Birchell G J and K Christopherson 2004 Survival growth and recruitment of larval andjuvenile razorback13 sucker (Xyrauchen texanus) introduced13 into13 floodplain13 depressions13 of the13 Green River Utah13 Final report13 Upper13 Colorado13 RiverEndangered Fish Recovery Program13 Project No C-shy‐6RZ Publication Number 04-shy‐1513 Utah13 Division of Wildlife13 Resources Salt Lake13 City13 Utah13 67 pages

Brannon E L 1993 The perpetual oversight of hatchery programs Fishery Research 1819-shy‐27

Brett J R 1979 Environmental Factors and growth pages 599-shy‐67513 InW S Hoar13 D13 J13 Randall and J R Brett (eds) Fish Physiology Volume 8 Bioenergetics and GrowthAcademic Press New York

Brooks J E 1986 Annual reintroduction and monitoring report for razorback suckerXyrauchen texanus in the Gila River Basin Arizona 1985 US Fish and WildlifeService13 Offices of Endangered13 Species and Fishery13 Resources Albuquerque 23 pp

51

13

Brunson13 R E and K D13 Christopherson13 200513 Larval13 razorback13 sucker and bonytailsurvival and13 growth13 in the13 presence13 of nonnative13 fish in the13 Baeser13 floodplainwetland of the middle Green River Final report prepared for Upper13 Colorado RiverBasin Endangered Fish Recovery Program Project No C-shy‐6-shy‐rz-shy‐bt Publication13 No 05-shy‐26 Utah13 Division of Wildlife13 Resources13 Vernal13 32 pp

Bulkley R V and R Pimentel 1983 Temperature preference and avoidance by adultrazorback suckers Transactions of the American Fisheries Society 112601-shy‐607

Burke13 T13 199513 Rearing13 wild razorback13 sucker larvae in13 lake-shy‐side13 backwaters13 LakeMohave ArizonaNevada Proceedings of the Desert Fishes Council 2635

Busacker G P I R Adelman and E M Goolish13 199013 Growth13 Pages 363 ndash 387 in C BSchreck and p B Moyle editors Methods for fish biology American FisheriesSociety Bethesda Maryland

Castro V B Grisdale-shy‐Helland S J Helland T Kristensen S M Jorgensen J Helgrud13 GClaireaux A P Farrell A Krasnov and H Takle 2011 Aerobic training stimulatesgrowth and promotes disease resistance in Atlantic salmon (Salmo salar)Comparative Biochemistry and Physiology -shy‐ Part A Molecular amp IntegrativePhysiology13 160(2) 278-shy‐290

Czapla T E 2002 Facilities plan for the production of endangered fishes to meet statestocking13 plans13 as13 part of the13 Upper13 Colorado13 River Endangered13 Fish RecoveryProgram Upper Colorado River Basin Recovery Implementation Program US Fishand Wildlife Service13 Denver13 9 pp

Davidson W 1997 The effects13 of exercise13 training on teleost fish a review of recentliterature Comput Biochem Physiol 117A67ndash75

Figiel Jr C R 2005 Annual report fiscal year 2004 Willow Beach National13 Fish HatcheryUS Fish and Wildlife13 Service Willow Beach 17 pp

Figiel Jr C R M E Ulibarri G Carmichael J Seals and J N Hanson 2005 Intensive13 fish13 culture of warmwater native fishes at a coldwater fish hatchery Pages 164-shy‐16613 inProceedings of two symposia restoring native fish to the lower Colorado13 River13 interaction13 of native13 and13 non-shy‐native13 fishes July13 13-shy‐1413 1999 Las Vegas Nevada USFish and Wildlife Service Southwest Region Albuquerque New Mexico

Gerking13 S D 1978 Ecology of freshwater fish13 production13 Halstead Press13 New13 York

Gustafson W and Q Bradwisch 2000 Wahweap operation and maintenance -shy‐-shy‐ UtahColorado River Recovery Program FY 2000 annual project report Project No 29cUtah13 Division of Wildlife13 Resources Page AZ 3pp

52

13

Hamman R L 1985 Induced spawning of hatchery-shy‐reared13 razorback sucker ProgressivFish Culturist 47(3) 187-shy‐189

Hanson J N 1996 Annual report fiscal year 1996 Willow Beach National Fish HatcheryUS Fish and Wildlife Service13 Willow Beach 9pp

Irving D S Seversen and M Montagne 2004 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2004 annual project13 report Report No 29b US Fish and13 Wildlife13 Service Vernal 3pp

Jorgensen E H and13 M Jobling 1994 Feeding and13 growth13 of exercised13 and13 unexercised13 juvenile Atlantic salmon in freshwater and performance after transfer to seawaterAquaculture International 2 154-shy‐164

Kaeding L R and D B Osmundson 198913 Colorado13 Squawfish13 and13 razorback sucker grow-shy‐out pond studies as part of conservation measures for the green mountain andRuedi reservoir water sales Final report for agreement number 6-shy‐AA-shy‐60-shy‐00150

Koebele13 B P13 198513 Growth and the size hierarchy effect an experimental assessment ofthree proposed mechanisms activity differences disproportional food acquisition13 pysiological stress Environmental Biology of Fishes 12 181-shy‐188

Kretschmann A E and L L Leslie 2006 Razorback sucker (Xyrauchen texanus) status13 reproduction and recruitment in Senator Wash Reservoir CA Final Report13 to USBurea of Reclamation Cooperative Agreement No 00-shy‐FG-shy‐34-shy‐ 0009 p 32 ArizonaGame and Fish Department Phoenix

Marsh13 P13 C13 1987a13 Digestive tract13 contents13 of adult razorback suckers13 in Lake13 MohaveArizona-shy‐Nevada Transactions of the American Fisheries Society 116117-shy‐119

Marsh P C 1987b Native fishes at Buenos Aires National Wildlife Refuge and ArizonaState University Research Park Arizona opportunities for management researchand public13 education13 on13 endangered species13 Proceedings of the Desert13 FishesCouncil 1967-shy‐78

Marsh P C 1994 Rearing native Colorado River fishes in golf course ponds Arizona StateUniversity Tempe 22 + pages

Marsh13 P13 C13 200013 Fish population13 status and evaluation13 in13 the Cibola13 High Levee PondFinal report agreement number 99-shy‐FG-shy‐30-shy‐00051 US Bureau of ReclamationBoulder City13 Nevada13 20 pages

Marsh P C and C A Pacey 1998 Growth of wild adult razorback suckers13 in Lake13 Mohave13 Arizona-shy‐Nevada13 Final report13 US Bureau of Reclamation Boulder City Nevada 25pages + appendices

53

13

Marsh P C B R Kesner and C A Pacey 2005 Repatriation as s management strategy13 to13 conserve a critically13 imperiled fish species North American Journal of FisheriesManagement 25 547-shy‐556

Marsh P C and C A Pacey 2005 Immiscibility of native and non-shy‐native13 fishes Pages 59-shy‐63 inMJ13 Brouder13 CL13 Springer13 and CS13 Leon13 editors13 Proceedings of two13 symposia Restoring native fish to the lower Colorado River interactions of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 NV and13 Restoring natural13 function within a modified riverine environment the lower Colorado River13 July13 8-shy‐913 1998 Las Vegas NV US Fish and13 Wildlife13 Service Southwest Region AlbuquerqueNew Mexico

Marsh13 P13 C13 and J13 E Brooks13 198913 Predation13 by ictalurid catfishes as a deterrent13 toreestablishment of hatchery-shy‐reared13 razorback sucker The Southwestern Naturalist34188-shy‐195

Matthews R A 2005 Ichthyopthirus multifiliis Fouquet and Ichthyopthirosis infreshwater13 teleosts13 Pages13 159-shy‐218 in Advances in Parasitology volume 59 J RBaker R Muller D Rollinson (eds) Academic Press

McCarthy13 M S and W L Minckley 1987 Age estimation for razorback sucker (PiscesCatostomidae) from13 Lake Mohave Arizona and Nevada Journal of the Arizona-shy‐Nevada Academy of Science 2187-shy‐97

Minckley13 W L13 198313 Status of the razorback13 sucker13 Xyrauchen texanus (Abbot)13 in13 thelower Colorado River basin13 The Southwestern13 Naturalist13 28(2) 165-shy‐187

Minckley13 W L13 199113 Native fished of the Grand Canyon13 region an obituary13 Pages 124-shy‐177 in Colorado River ecology and dam13 management National Academy PressWashington13 DC

Minckley13 C13 O and M LaBarbara13 199913 Report13 on13 native fish grow-shy‐out facilities13 at Cibolaand Imperial National Wildlife Refuges 1993-shy‐199513 US Fish and13 Wildlife Service13 Parker Fishery Resources Office Parker Arizona

Modde13 T13 199613 Juvenile razorback sucker (Xyrauchen texanus) in a managed wetlandadjacent13 to the Green13 River13 Great13 Basin13 Naturalist13 56375-shy‐376

Modde T KP Burnham and E J Wick 1996 Population status of the razorback sucker13 inthe middle Green River (USA) Conservation13 biology 10 110-shy‐119

Modde13 T13 and G13 B Haines13 200513 Survival13 and growth of stocked razorback13 sucker andbonytail in multiple floodplain wetlands of the middle Green River under resetconditions13 Final report prepared for Upper Colorado13 River13 Basin RecoveryImplimentation Program US Fish and Wildlife Service Vernal 66 pp

54

13

Modde T Z H Bowen and D C Kitcheyan 2005 Spatial and temporal use of a spawning13 site in the middle Green River by wild hatchery-shy‐reared13 razorback suckers13 Transactions of the American Fisheries Society 134937-shy‐944

Mueller13 G13 199213 The native fish work13 group13 -shy‐ a multiagency endeavor to improve thestatus of the razorback sucker in Lake Mohave AZ-shy‐NV13 Proceedings of the DesertFishes Council 2369

Mueller G 1995 A program13 for maintaining the razorback sucker in Lake MohaveAmerican Fisheries Society Symposium 15127-shy‐135

Mueller13 G13 200613 Ecology of the bonytail13 and razorback13 sucker and the role of offchannelhabitats13 in their13 recovery Scientific13 investigations13 report 2006-shy‐5065 US GeologicalSurvey13 Denver

Mueller G and E Wick 1998 Testing of golf course ponds at Page Arizona for suitability13 as grow-shy‐out facility for razorback sucker using surplus fish from13 Ouray NationalFish Hatchery National Park Service US Fish and13 Wildlife13 Service and UtahDivision of Wildlife13 Resources 28 pages

Mueller13 G13 and T13 Burke13 200513 Survival13 of young13 razorback13 sucker (Xyrauchen texanus) inrelation to13 stocking rates13 (fishha)13 and13 in the presence13 or absence13 of predatorcommunities in Lake Mohave Arizona-shy‐Nevada13 Pages13 155-shy‐16313 in Proceedings of two13 symposia restoring native fish to the lower Colorado River interaction13 of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 Nevada US Fish and Wildlife13 Service Southwest Region Albuquerque New Mexico

Mueller13 G13 J13 Carpenter13 and P13 C13 Marsh13 200413 Cibola13 High Levee Pond annual report 2004US Geological Survey Fort Collins13 Science Center13 Colorado13 and Arizona StateUniversity Tempe 23 pages

Nesler T P K Christopherson J M Hudson C W McAda F Pfeifer and T E Czapla 2003An integrated stocking plan for razorback sucker bonytail and Colorado13 pikeminnow for the Upper Colorado River Endangered Fish Recovery ProgramAddendum13 to State Stocking Plans Upper Colorado River Basin Recovery13 Implementation Program 12 pp

Papoulias13 D and W13 L Minckley13 1992 Effects13 of foo availability13 on survival and growth13 of larval razorback suckers13 in ponds Transactions of the American Fisheries Society121340-shy‐355

Paukert13 C P D L Ward13 P J Sponholtz13 and K13 D Hilwig13 Effects13 of repeated hoopnetting13 on bonytail chub13 Journal of Freshwater13 Ecology13 20(4) 649-shy‐653

Pfeifer F M13 C Baker13 and M13 Montagne13 199913 Propagation13 facilities13 in the13 Grand Valley13 (24 Road13 Hatchery13 Horsethief13 Ponds and13 grow-shy‐out ponds) for captive rearing of

55

13

endangered13 fishes for the13 Upper Colorado13 River Basin13 Colorado13 River Recovery13 Program FY 99 annual project report Project No 29a13 US Fish and Wildlife Service13 Grand13 Junction13 5pp

Pfeifer F S Seversen and M Montagne 2003 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2003 annual reportProject No 29b13 US Fish and Wildlife13 Service Vernal13 4pp

Rabago-shy‐Castro J L Sanchez13 J G Perez-shy‐Castaneda R and13 Gonzalez-shy‐Gonzlez A 2006Effects of the prophylactic use of Romet-shy‐3013 and13 copper13 sulfate13 on growth13 condition13 and feeding13 indicies in13 channel13 catfish (Ictalurus punctatus) Aquaculture 253 343-shy‐349

Reinitz GL L E Orme and F N Hitzel 1979 Variations of body compositio and growth13 among strains of rainbow trout Transactions of the American Fisheries Society 108204-shy‐207

Ruppert13 J13 B P B Holden13 and P D Abate 1999 Age estimation and growth of razorbacksucker13 Xyrauchen texanus in Lake13 Mead Nevada Proceedings13 of the Desert FishesCouncil 3040

Schnoor K D and J Logan 2002 Operation and maintenance of JW Mumma nativeaquatic13 species restoration facility Colorado Colorado River Recovery Program FY2002 annual project report13 Project No 29d Colorado13 Division of Wildlife Alamosa3pp

Salisbury13 L13 1998 Factors13 affecting razorback13 sucker growth13 in Lake13 Mohave backwaters13 MS Thesis13 Unviersity13 of Nevada13 Las13 Vegas

Schooley J13 D13 and P C13 Marsh13 2007 Stocking of endangerdd13 razorback13 suckers13 in thelower Colorado River Basin13 over three decades 1974-shy‐2004 North American Journalof Fisheries Management 27 43-shy‐51

Severson S H H M Tyus and G B Haines 1992 An evaluation of feeds for raisingrazorback sucker Xyrauchen texanus Journal of Applied Aquaculture 155-shy‐65

Toney D P 1974 Observations13 on the13 propagation13 and13 rearing13 of two13 endangered species13 in a hatchery environment Proceedings of the Annual Conference of the Western13 Association of State Game and Fish Commissions 54 252-shy‐259

Tyus H M13 1998 Razorback sucker13 (Xyrauchen texanus) recovery plan13 University13 ofColorado Center for Limnology Boulder13 76 pages

Tyus H M13 and13 S H Severson 1990 Growth13 and13 survival of larval razorback suckers fedfive formulated diets The Progressive Fish Culturist 52197-shy‐200

56

13

Ulibarri M E 2003 Annual report fiscal year 2001 Dexter National Fish Hatchery13 andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 26 pages

Ulibarri M E 2003 Annual report fiscal year 2002 Dexter National Fish Hatchery andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 59 pages

USBR 2006 Lower13 Colorado13 River Multi-shy‐Species Conservation Program final fishaugmentation plan Boulder City 19 pp

USFWS 2002 Razorback sucker (Xyraouchen texanus) recovery goals Amendment andsupplement to the Razorback Sucker Recovery Plan13 US Fish and Wildlife Service13 Region 6 Denver13 Colorado

USFWS 1999 Annual report 1999 Ouray National Fish Hatchery Vernal 25pp

USFWS 2004 Management plan for the big-shy‐river13 fishes of the13 lower13 Colorado13 river basinamendment and supplement to the bonytail humpback chub Coloradopikeminnow and razorback sucker recovery plans

USFWS13 2005 Station13 profile13 of the13 Dexter13 National Fish Hatchery13 and Technology CenterUS Fish and Wildlife13 Service Dexter

Valdez R A P G Mangan R Smith and B Nilson 1982 Upper Colorado River fisheriesinvestigations13 inW H Miller J J Valentine D L Archer H M Tyus R A Valdezand L13 Kaeding13 editors13 Colorado River Fishery13 Project13 Part 2 Field13 investigations13 US Bureau of Reclamation Salt Lake City Utah

WBNFH 2004 Culture methods of the endangered razorback sucker Xyrauchen texanusUS Fish and Wildlife13 Service Willow Beach National Fish Hatchery13 8 pp

Ward D 2008 Effects of disease treatments on growth of razorback sucker ReportSubmitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 Inpartial fulfillment of work task C10 agreement number 06FG30039

Ward13 D13 M Childs and W Persons 2007 Factors13 affecting13 growth13 of razorback sucker13 (Xyrauchen texanus) in captivity Literature review and knowledge assessmentReport Submitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 In partial fulfillment of work task C10 agreement number 06FG30039

57

Appendices

Appendix 1 Survey Questions Survey of Razorback Sucker Culture in the

Southwestern United States

The enclosed survey is being distributed by the Arizona Game and Fish Department to razorback sucker culture facilities throughout

the Southwestern United States The purpose of this survey is to consolidate information regarding culture of this species so that

appropriate facility improvements can be considered for Bubbling Ponds Hatchery in Arizona Specifically we wish to increase

growth rate and production efficiency at the hatchery Information gathered in this survey will be summarized in a final report to US

Bureau of Reclamation in Boulder City NV and disseminated to all facilities that participate in the survey A workshop to discuss

the findings of this study as well as to share general information concerning razorback sucker culture will be organized by the

Arizona Game and Fish Department at the conclusion of this study and all participants will be invited

Thank you for taking the time to fill out this survey Please contact Mike Childs if you have questions or would like to discuss the

survey

Mike Childs

mchildssedonanet

(928) 639-1346

(928) 634-1279

Facility_____________________________________ Date___________________

Contact Phone _____________________________

ContactPerson_______________________________

Contact Email _______________________________

1 Water quality ranges at this culture facility

Season

Spring (Mar-May) Summer (Jun-Aug) Fall (Sept-Nov) Winter (Dec-Feb)

Temperature (C)

PH

DO (mgL)

PO4 (mgL)

TDS (mgL)

Hardness (mgL)

CaCO3

Pathogens

37

13

amount of time in a pond during the growing season These13 data give a snapshot of growth13

rates13 at the13 facility13 and13 provide13 the basis for comparisons throughout our study

Growth rate13 in an unlined pond

In addition13 to 6 ponds lined with heavy plastic13 sheeting13 Bubbling Ponds Fish13

Hatchery maintains two narrow and deep (same dimensions as lined ponds13 Figure13 4)13 and13

three large13 shallow unlined ponds These earthen13 ponds typically have vegetation and

associated aquatic invertebrates that may better simulate natural environments by

providing cover and improved food diversity or quality Therefore these unlined ponds

may be expected to produce higher growth rates and potentially improved survival that is

more similar to growth rates observed in more natural grow-shy‐out facilities13 Historically13 the13

large13 shallow13 ponds have produced very large fish when13 utilized at low13 fish density13 The

narrow13 deep earthen13 ponds are13 used to grow13 fry13 at high density in their first13 year of life

The major downside to unlined ponds is the difficulty in harvesting fish where a lined

pond might take 8-shy‐1013 people13 a half13 day13 to13 harvest13 lined13 ponds13 require13 intensive13 weeding13

to allow seines to be pulled and therefore require many more personnel-shy‐hours13 In addition13

to harvest challenges the shallow earthen ponds tend to suffer from13 dissolved oxygen

crashes during the summer Unlined ponds also may maintain higher13 populations13 of non-shy‐

target species such as bluegill sunfish mosquito fish and bullfrog tadpoles We measured

growth rates of suckers in a large shallow earthen pond for comparison to growth in lined

ponds13

Figure13 4 Lined13 and13 earthen ponds13 of similar dimensions (approx 1000000 gallons first

and second panels) and a large13 shallow13 earthen13 pond (third panel)

38

13

Effect of sorting on growth

Razorback13 suckers13 are13 currently13 sorted13 after their first13 year of growth13 They are13

typically removed from13 one of the13 upper earthen13 ponds and13 split into13 two13 lined13 ponds for

subsequent grow-shy‐out13 The larger13 fish (gt approximately 140 mm) are placed into one pond

and the smaller individuals in another It is possible that the larger fish were more

aggressive or adept13 at taking food so this sorting process is intended to allow smaller fish

to improve their growth rate

Effect of Ich on razorback sucker growth rates

We13 evaluated13 growth13 rates13 of razorback sucker13 in the13 presence13 and absence of the

ectoparasite13 Ich (Ichthiopthirus multifiliis) Ich outbreaks can occur in wild populations13 but

hatcheries13 have13 proven excellent locations13 for Ich because13 of very high fish densities13 which13

facilitate13 the13 transfer13 of Ich13 between13 fish This common fish parasite causes direct mortality13

to razorback13 suckers as well13 as secondary bacterial13 infections13

The open spring and13 ditch13 which13 provides water to the Bubbling13 Ponds Hatchery

has long13 been infested with mosquitofish (Gambusia affinis) that harbor13 the13 Ich parasite13

and allow13 it13 to enter the hatchery with incoming13 water13 The solution13 to13 the13 Ich problem13

was to remove the mosquitofish host using13 Rotenone Razorback13 sucker growth13 rates were13

then tracked in13 the absence of this parasite for 4 months and compared with growth rates

after Ich returned to the pond and from13 previous years

Methods

Razorback growth rate in lined ponds

On May 14 2008 141 razorback suckers were tagged with 12 mm PIT tags (1342

kHz) and placed in Pond 3 (approximately 1100000 gallons13 Figure13 4)13 at Bubbling13 Ponds

Fish Hatchery Fifty-shy‐three of these tags were recovered two months later when a large

Ichthyophthirius multifilis (Ich) outbreak killed many fish in the pond On October 15 2008

an additional13 145 PIT tagged13 fish were13 also placed into Pond13 3 On13 May13 14 2009 Pond13 3

was harvested and a total13 of 141 PIT tagged fish were recovered13 Of the tagged fish13 26 fish

had13 been13 in the13 pond since May13 of 2008 (378 days13 o growth) and 115 had been13 in13 the

39

13 40

pond since October13 15 2008 (211 days13 of growth) Numbers of fish in Pond 3 after the Ich

outbreak and for the majority of the period of growth were between 3 000 and 4000 fish

A Hobotempreg temperature13 logger13 was13 also13 installed13 in Pond 3 one meter below the water

surface13 near13 the13 outflow and13 recorded water temperature every 3 hours to allow analysis

of the effects of water temperature on growth rate (Figure13 5) This Hobotemp data is

representative of other pond temperatures throughout this study

In a second experiment 210 adult13 razorback suckers13 were13 PIT tagged13 on13 May 14

2009 and13 placed13 into13 Pond13 3 upper to13 evaluate13 growth13 rates13 of larger13 razorback suckers13 at

Bubbling13 Ponds Hatchery13 under current13 rearing13 conditions13 Size of these fish at tagging13

was (mean = 285 mm range = 205 ndash 396 mm) These fish remained in the pond for 257

days and were harvested on Jan 25 2010 to provide information on growth rates of larger

razorback suckers13 under13 current rearing conditions

Figure 513 Temperatures (degC) inrearing pond at BubblingPonds Hatchery from July toSept 2009 (top graph)13 andfrom Nov to Dec 2009 (Lowergraph) Temperaturesrecorded with a Hobotempregremote data logger13 every 3hours

13

Growth rate13 in an unlined pond

To document razorback sucker growth in earthen ponds we introduced13 225 tagged13

razorback suckers13 into13 Pond13 1 lower13 (Figure 4) in February 3 2010 Additional tagged fish

from13 other studies were added to the pond throughout the growing season and the density

of 1 lower reached a maximum13 of nearly 7000 fish in early summer 2010 Density was

reduced to approximately 6000 fish by capturing fish with hoop nets on June 3 2010 54 of

these fish were tagged fish and returned to 1 lower after being weighed and measured The

pond was harvested on January13 2713 2011 and a total13 of 254 tagged fish out13 of 4296 fish

total were removed from13 the pond The pond was harvested on January 27 2011 (358 days13

of growth) and the tagged fish were weighed and measured Total number of razorbacks in

the pond at harvest13 was 4296

Effect of sorting practices on growth rates

On March 1113 200913 Pond13 5 upper was13 harvested13 and13 split into13 two13 separate13 groups

Two hundred of the smaller fish (average size = 122 mm TL) were PIT tagged and placed

into13 Pond13 7 upper and13 200 of the13 larger13 fish (average = 160 mm TL) were PIT tagged and

placed int Pond13 8 upper Density13 in Pond13 7 was13 4500 fish and13 in Pond13 8 there13 were13 6500

fish These ponds were then harvested after 1 year and growth rates were compared to

give information on the effects of current sorting practices Hobotempreg temperature

loggers were installed in13 Ponds 7 and13 8 during13 the13 grow-shy‐out period with13 water13

temperature recorded every 2 hours13 (Figure13 6)

Effect of Ich on razorback sucker growth rates

Bubbling Ponds spring was treated with Rotenone (CFT Legumine 5) at a

concentration of 2 ppm13 to remove all mosquitofish from13 the spring The treatment

consisted of two treatments 6 hours in duration on two consecutive days (April 12 -shy‐ 13)

using13 drip13 stations13 and13 backpack sprayers13 followed13 by13 an13 additional 6 hours13 of

detoxification using sodium13 permanganate Although 12 mosquitofish were captured in the

spring pond the week following the treatments subsequent minnow trapping (20 traps

checked13 daily13 for 3 weeks) did not capture any additional fish until August 11 2010 when

41

13

juvenile mosquitofish were again detected in the spring pond Minnow traps have

subsequently been set daily with several hundred individuals removed To evaluate if Ich

was also again present in the spring we captured 15 mosquitofish from13 the spring pond on

three separate days and placed them13 in an aquaria at 25 degC with 5 longfin dace known to be

free of Ich These fish were monitored for 2 weeks with no signs of Ich developing This

indicates that even though mosquitofish have returned to the spring pond the parasite is no

longer present13 although how13 long13 this condition13 will13 persist13 is unknown13

On May 1113 201013 200 juvenile razorback13 suckers were harvested out13 of Pond 5

upper (2009 year Class from13 Dexter National Fish Hatchery) and were PIT tagged and

placed into Pond 8 to evaluate if growth rates at bubbling ponds hatchery have improved

following the renovation of the spring and the removal of the Ich parasite Unfortunately13

on Sept13 8 2010 Ich was13 again13 detected13 in Pond 8 and the pond was immediately seined

and 74 tagged fish were measured to obtain growth information for the 4-shy‐month period

during13 which13 the13 pond13 was13 Ich-shy‐free13

Figure13 6 Temperatures (degC) in rearingponds 7 and 8 at Bubbling Ponds Hatchery13 from March 2009 ndash March 201013 pond 7(top13 graph)13 and13 pond 8 (Lower13 graph)13 Temperatures recorded with a Hobotempregremote data logger every 3 hours

42

13

Results

Growth in Lined Ponds

Razorback suckers13 that had been13 in13 Pond 8 upper for the13 entire13 year13 grew an13

average of 0263 mmday (789 mmmonth) and razorback suckers that had been in the

pond for 7 months (Oct -shy‐ May) grew13 on13 average of 028 mmday (843 mmmonth) (Figure13

7) These growth13 rates13 did not significantly13 differ Fish density13 in Pond 3 during13 the13

majority of the growth period was13 00032 ndash 00036 fishgallon13 Additionally no13 significant

differences in growth rate were observed between fish smaller than 210 mm TL and fish

larger than 210 mm TL when all recaptured fish were combined

We also measured the growth rate of very large fish in a lined pond On Jan13 2513 201013

156 adult fish with PIT tags were recovered from13 Pond 3 upper13 These fish were13 in the13

pond for 257 days and experienced an average13 growth13 rate13 of 024mmday or 73

mmmonth (Figure13 7)13 This growth13 rate13 is slightly13 lower13 than13 the13 average13 growth13 rate13

observed13 at Bubbling13 Ponds Hatchery in other studies (0275 mmday 825 mmmonth)

but may not be biologically meaningful We would expect larger13 fish to13 have13 reduced

growth rates according to a typical Von Bertalanfy growth model (Bertalanffy 1957) but it

appears that13 over the size range we evaluated (300 -shy‐ 450 mm TL) growth rates have not

slowed significantly compared to that of smaller13 fish grown at Bubbling Ponds13 Hatchery

Growth13 of razorback suckers13 is known13 to13 slow as13 fish reach13 larger13 sizes but it appears13 this13

reduced growth rate may not really start to be biologically meaningful at Bubbling Ponds

Hatchery13 until razorback suckers13 exceed 450 mm TL

Growth in unlined ponds

Growth13 rates13 for the13 fish recaptured13 during13 the Pond 1 lower13 thinning13 (120 days13 in

the pond) was 024 plusmn 003 mmday (729 plusmn 090 mmmonth) (Figure13 8)13 Fish13 that were13 in

the pond for nearly the entire year grew13 an13 average13 of 024 plusmn 001 mmday (726 plusmn 027

mmmonth) These growth rates are surprisingly the lowest measured growth rates for

any part of our study and differ significantly from13 every other measured growth rate

except very large13 fish (Figure13 9)13 Separating13 out13 large fish that13 were in13 the pond for the

entire year makes no difference fish that were added to the pond at TL lt300 mm grew

43

13

Gro

wth

Rat

e (m

md

ay)

020

026

032

0244 plusmn 001 mmday (733 plusmn 028 mmmonth) and and those with TL gt= 300 mm at the

start of the experiment grew 022 plusmn 003 mmday (651 plusmn 101 mmmonth)

Razorback Growth Rates in Lined Ponds

Figure 7 Growth ofrazorback suckers in(mmday plusmn standard error)in Pond 8 upper in 2008-shy‐2009 An ANOVA did notdetect any significantdifferences

7 Months Full Year 300+ mm fish

Effects of sorting on growth

One hundred and seventy five tagged razorback suckers were recovered from13 Pond

8 upper13 on March13 24 2010 (378 days13 of growth)13 These were13 the13 larger sorted13 fish (gt140

mm TL) that came out of Pond13 5 on March13 11 2009 One13 hundred and13 twenty13 two13 tagged13

razorback suckers were also recovered from13 Pond13 7 upper on March13 31 2010 (385 days13 of

growth)13 These were13 the13 smaller sorted13 fish (lt140 mm TL) that came out of Pond13 5 on

March 1113 200913 No significant differences in growth rate (mmday) were observed among

larger fish in Pond 8 and smaller fish in Pond 7 (pgt005 ANOVA) (Figure 10)13 indicating

that13 sorting may have helped to offset the original slower growth trajectory of the smaller

fish Temperatures of Ponds 7 and 8 upper remained similar throughout the year13 (Figure

5)

44

13

13

13

Gro

wth

Rat

e (m

md

ay)

Gro

wth

Rat

e (m

md

ay)

020

026

032

020

026

032

Razorback Growth in an Unlined Pond

Figure 8 Growth of razorbacksuckers (mmday plusmn standard error) in Pond 1 lower (an unlined pond)in 2010-shy‐2011 An ANOVA did notdetect any significant differences

6 Months 12 Months lt 300 mm Fish 300+ mm Fish Growth Growth

Lined vs Earthen Ponds 1 year of growth

Figure 9 Growth of razorbacksuckers (mmday plusmn standard error) in lined and unlined ponds A t-shy‐test13 did not detect a significantdifference

Lined Pond Unlined Pond 1 Yr Growth 1 Yr Growth

45

13

Effect of Sorting G

row

th R

ate

(mm

day

) G

row

th R

ate

(mm

day

)

032

020

026

032

020

026

Smaller Fish Larger Fish

Effect of Ich

Figure 10 Average growthof razorback suckers(mmday plusmn standard error)that were size-shy‐sorted intosmall fish (pond 7) and largefish (pond 8) populations At-shy‐test did not detect asignificant difference

Figure 11 Average growth ofrazorback suckers (mmday plusmnstandard error) after Ich wasremovd from the hatcheryrsquos springand after Ich was again detected inthe pond The growth rate withoutIch is significantly higher than boththe rate after Ich and the ourstudyrsquos average annual growth ratein lined ponds (ANOVA p =00003)

Growth without Ich Growth With Ich Average Annual 4 months 4 months Growth Rate

46

13

Effect of Ich on razorback sucker growth rates

Seventy-shy‐four13 tagged13 razorback suckers13 were13 recovered from13 Pond 8 on September

15 2010 These fish had13 been13 in the pond for 4 months and experienced a growth rate of

032 mmday or 97 mmmonth (Figure13 11)13 This growth13 rate13 is significantly higher (p =

005 two sample t-shy‐test) than the mean growth rate for the same group13 of tagged fish after

Ich detection (022 mmday or 65 mmmonth) and significantly higher than any other

individual growth13 rates13 observed13 to13 date13 at Bubbling13 Ponds Hatchery13 (Figure13 11)13 If this13

growth13 rate13 were13 extended throughout13 the entire13 year13 fish on average from13 Ich-shy‐free13 ponds13

would be 16 mm longer than fish from13 ponds infested with Ich Studies conducted at

Bubbling Ponds hatchery in 2008 (Ward 2008) did not reveal any effects of the treatment

chemicals on razorback sucker growth rates so it13 is likely that13 the parasite outbreaks

themselves are causing reducing growth rates rather than the chemicals used to treat the

parasites13

Conclusions

Our results suggest that under typical hatchery operations (maximizing number of

fish produced)13 the growth13 rate13 of razorback13 suckers13 is relatively13 consistent at Bubbling13

Ponds hatchery13 at 02-shy‐03 mmday (6-shy‐9 mmmonth)13 but is lower than growth13 rates13 at

other13 facilities (02 ndash 18 mmday Ward et al 2007)13 This growth13 rate13 has13 been13 constant in

both lined and unlined ponds and at all fish densities we were able to measure To achieve13

growth13 rates13 substantially higher than this will likely require13 significant changes in rearing

practices that may not be practical in order to reach numerical production13 goals

Temperature is a key variable in fish growth but seasonal growth patterns

described13 above13 (Figure13 5) demonstrate that water temperatures are high enough in

winter to maintain razorback growth Differences in water temperature by season

currently13 do not fluctuate more than 10degC at Bubbling Ponds because of the continuous

supply of water flowing through each pond (approx 225 gallonsmin) These high water

flows appear to keep pond temperatures within the thermal preference13 for razorback

suckers13 (1213 -shy‐ 28 degC Bulkley and Pimentel 1983) throughout the entire year with

temperatures rarely dropping13 below 16deg13 C (Figures 513 6)13

47

13

Fish density is another key variable in fish growth and though the number of fish in

a pond during our study ranged from13 3000 to 700013 fish we13 did not find any13 correlation13

between13 density and growth rate13 This might yield two conclusions First13 razorback

growth13 may be changed equally13 by13 densities13 at the13 hatchery13 (ie13 a density13 of 3000 fish in a

pond is as stressful13 for razorbacks as a density13 of 7000 fish) An alternative is that other

factors13 such as disease outbreaks have13 stronger13 control over fish growth13 than13 density13

Fish density13 would13 have13 to13 be13 experimentally manipulated to test13 this13 and hatchery

operations (producing the maximum13 number of fish) prevented our manipulating density13

in ponds for this13 work The trouble with manipulating density demonstrates the difficulties

associated with changing13 hatchery13 practices experimenting with density would have

prevented BPH from13 meeting13 production13 goals Given that the stocking of smaller

razorbacks has met with very little success perhaps BPH goals could be changed from13

producing 12000 fish at 300+ mm per year to a smaller number of very large fish each

year Growing13 fewer13 larger13 fish could potentially be accomplished in the same time frame

as more smaller fish but a better understanding of how density alters growth rate would

be required to be confident13 of this

The very slow growth13 in the13 earthen13 unlined13 Pond 1 lower13 was very surprising We13

had13 anticipated13 that the13 diversified diet13 cover and13 other13 habitat features13 provided by13

unlined ponds would yield dramatically increased growth rates However these traits were

not enough to offset high fish densities and in fact the unlined pond in our study13 suffered

mortality to bring densities down to that observed normally in lined ponds

Our data13 suggest13 that razorbacks13 sucker13 growth13 rates13 are13 higher in lined13 ponds13

However we13 think the reasons13 for the13 very slow growth we observed13 in the13 unlined13 pond13

in our study13 is instead13 linked13 to13 the13 usage13 of Pond 1 lower13 during13 the13 study13 rather13 than13

intrinsic13 slow growth13 in earthen13 ponds First the pond was at extremely high density for at

least part of the study The volume of Pond 1 lower has not been estimated but hatchery

managers suggest 1500-shy‐2000 fish is an appropriate number of individuals so this pond

was at a very high density for much of the experiment Second dissolved oxygen is often

very low in the13 large13 earthen13 ponds during the heat of summer much lower than that of

lined ponds This will both limit the number of fish that can survive in the pond and almost

certainly13 increases stress13 of these13 fish potentially13 reducing growth13 The DO crashes also13

48

13

limit the amount of feed hatchery managers can give fish in these ponds sometimes for

days or weeks at a time which further reduces growth during warm13 weather

Our data13 suggests that13 growth rates at the Bubbling13 Ponds Fish Hatchery are likely

as high as possible given13 the pond densities required to meet production goals and the Ich-shy‐

infested water that feeds the facility Sorting practices are successful in helping as many

fish as possible reach stocking length as fast as possible Unlined ponds may be able to

grow13 large13 fish at low13 densities13 but whatever factors allow13 for that13 growth are not13 able to

overcome high fish density The removal of invasive13 fis that act as13 a host for the13 parasite13

Ich fish from13 the Bubbling13 Ponds spring13 allowed the highest13 growth rate at 032 mmday13

(96 mmmonth) but that growth rate decreased again as Ich re-shy‐infested13 the13 hatchery13

Consistently13 achieving13 growth13 rates13 as high or substantially13 higher than13 this13 will likely13

require13 significant changes in rearing practices that may not be practical in order to13 reach13

numerical production13 goals

Two major changes that might result in higher growth rates are substantially

reducing fish density and modifying the way spring water is delivered to the facility (via

either repeated chemical treatments or enclosed concrete water diversions) to eliminate

Ich from13 the hatchery source water Other potential changes not address by our work

include13 flow-shy‐training razorbacks much previous literature including MSCP-shy‐funded13 work

on razorback suckers13 suggests13 that fish growing13 in flowing water will grow13 faster than fish

in still water (Jorgensen and Jobling 1994) Furthermore there are a wide variety of

potential benefits associated with growing13 fish13 in flowing13 water in addition13 to increased

growth13 rates13 (Davidson13 199713 Castro13 et al13 2011) Another option13 for increasing13 growth13

rates13 include13 changing to13 intensive13 culture13 in large circular13 tanks

Finally given that the stocking of smaller razorbacks has met with very little

success13 perhaps13 BPH13 goals13 could13 be13 changed from13 producing 12000 fish at 300+ mm per

year to a smaller number of very large fish each year Growing fewer larger fish could

potentially be accomplished in the same time frame as more smaller fish but a better

understanding13 of how density13 alters growth13 rate13 would13 be13 required to13 be13 confident of this

49

13

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower13 Colorado13 River Multi-shy‐Species13

Conservation Program13 (LCRMSCP) under Work Task C10 We13 thank Ty Wolters13 Tom13

Burke13 and Eric13 Volkman for their support of this research and Frank Agygos and Dave

Billingsly13 of the Bubbling13 Ponds Fish Hatchery13 for their willingness to participate in13 this

research13 and13 for their technical assistance We also thank the LCRMSCP fish group from13

Boulder City13 NV for their assistance with harvesting13 ponds and tagging13 fish13

50

13

Literature13 CitedAnders P J 1998 Conservation aquaculture and endangered species can objective science13

prevail13 over risk13 anxiety Fisheries 23(11) 28-shy‐31

Anderson R O and R M Nuemann 1996 Length weight and associated structural indicesPages 447 ndash 482 in B R Murphy13 and D13 W Willis13 editors13 Fisheries techniques13 2ndedtion American Fisheries13 Society13 Bethesda13 Maryland

Bain M B J T Finn and H E Brooks 1988 Streamflow regulation and fish communitystructure13 Ecology13 69382-shy‐392

Bays J H Zarbock R Whitman and T Murphy 2005 Conceptual design and managementof native13 fish refugia on the13 lower13 Colorado13 River In13 CL Spring13 and13 S Leoneditors Proceedings of two symposia Restoring native fish to the lower ColoradoRiver13 interactions13 of native and non-shy‐native13 fishes 13ndash1413 July13 1999 Las13 Vegas13 Nevada13 Restoring13 natural function within a modified riverine environment thelower Colorado River13 8ndash913 July13 1998 U S Fish and13 Wildlife13 Service Southwestern13 Region Albuquerque New Mexico Pages 167-shy‐177

Bertalanffy L Von 1957 Quantitative laws in metabolism13 and growth13 Q Rev Biology 32217 ndash 231

Bingham T B Scheer and C McAda 2003 Propagation facilities in Grand Valley (24 RoadHatchery Horsethief13 Ponds and13 grow-shy‐out ponds) for captive13 rearing13 ofendangered13 fishes for the13 upper13 Colorado13 River basin13 Colorado River RecoveryProgram FY2003 annual project report13 US Fish and13 Wildlife13 Service GrandJunction13 4pp

Birchell G J and K Christopherson 2004 Survival growth and recruitment of larval andjuvenile razorback13 sucker (Xyrauchen texanus) introduced13 into13 floodplain13 depressions13 of the13 Green River Utah13 Final report13 Upper13 Colorado13 RiverEndangered Fish Recovery Program13 Project No C-shy‐6RZ Publication Number 04-shy‐1513 Utah13 Division of Wildlife13 Resources Salt Lake13 City13 Utah13 67 pages

Brannon E L 1993 The perpetual oversight of hatchery programs Fishery Research 1819-shy‐27

Brett J R 1979 Environmental Factors and growth pages 599-shy‐67513 InW S Hoar13 D13 J13 Randall and J R Brett (eds) Fish Physiology Volume 8 Bioenergetics and GrowthAcademic Press New York

Brooks J E 1986 Annual reintroduction and monitoring report for razorback suckerXyrauchen texanus in the Gila River Basin Arizona 1985 US Fish and WildlifeService13 Offices of Endangered13 Species and Fishery13 Resources Albuquerque 23 pp

51

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Brunson13 R E and K D13 Christopherson13 200513 Larval13 razorback13 sucker and bonytailsurvival and13 growth13 in the13 presence13 of nonnative13 fish in the13 Baeser13 floodplainwetland of the middle Green River Final report prepared for Upper13 Colorado RiverBasin Endangered Fish Recovery Program Project No C-shy‐6-shy‐rz-shy‐bt Publication13 No 05-shy‐26 Utah13 Division of Wildlife13 Resources13 Vernal13 32 pp

Bulkley R V and R Pimentel 1983 Temperature preference and avoidance by adultrazorback suckers Transactions of the American Fisheries Society 112601-shy‐607

Burke13 T13 199513 Rearing13 wild razorback13 sucker larvae in13 lake-shy‐side13 backwaters13 LakeMohave ArizonaNevada Proceedings of the Desert Fishes Council 2635

Busacker G P I R Adelman and E M Goolish13 199013 Growth13 Pages 363 ndash 387 in C BSchreck and p B Moyle editors Methods for fish biology American FisheriesSociety Bethesda Maryland

Castro V B Grisdale-shy‐Helland S J Helland T Kristensen S M Jorgensen J Helgrud13 GClaireaux A P Farrell A Krasnov and H Takle 2011 Aerobic training stimulatesgrowth and promotes disease resistance in Atlantic salmon (Salmo salar)Comparative Biochemistry and Physiology -shy‐ Part A Molecular amp IntegrativePhysiology13 160(2) 278-shy‐290

Czapla T E 2002 Facilities plan for the production of endangered fishes to meet statestocking13 plans13 as13 part of the13 Upper13 Colorado13 River Endangered13 Fish RecoveryProgram Upper Colorado River Basin Recovery Implementation Program US Fishand Wildlife Service13 Denver13 9 pp

Davidson W 1997 The effects13 of exercise13 training on teleost fish a review of recentliterature Comput Biochem Physiol 117A67ndash75

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Hamman R L 1985 Induced spawning of hatchery-shy‐reared13 razorback sucker ProgressivFish Culturist 47(3) 187-shy‐189

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Kaeding L R and D B Osmundson 198913 Colorado13 Squawfish13 and13 razorback sucker grow-shy‐out pond studies as part of conservation measures for the green mountain andRuedi reservoir water sales Final report for agreement number 6-shy‐AA-shy‐60-shy‐00150

Koebele13 B P13 198513 Growth and the size hierarchy effect an experimental assessment ofthree proposed mechanisms activity differences disproportional food acquisition13 pysiological stress Environmental Biology of Fishes 12 181-shy‐188

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Marsh13 P13 C13 1987a13 Digestive tract13 contents13 of adult razorback suckers13 in Lake13 MohaveArizona-shy‐Nevada Transactions of the American Fisheries Society 116117-shy‐119

Marsh P C 1987b Native fishes at Buenos Aires National Wildlife Refuge and ArizonaState University Research Park Arizona opportunities for management researchand public13 education13 on13 endangered species13 Proceedings of the Desert13 FishesCouncil 1967-shy‐78

Marsh P C 1994 Rearing native Colorado River fishes in golf course ponds Arizona StateUniversity Tempe 22 + pages

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53

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Marsh P C B R Kesner and C A Pacey 2005 Repatriation as s management strategy13 to13 conserve a critically13 imperiled fish species North American Journal of FisheriesManagement 25 547-shy‐556

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Marsh13 P13 C13 and J13 E Brooks13 198913 Predation13 by ictalurid catfishes as a deterrent13 toreestablishment of hatchery-shy‐reared13 razorback sucker The Southwestern Naturalist34188-shy‐195

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Minckley13 W L13 198313 Status of the razorback13 sucker13 Xyrauchen texanus (Abbot)13 in13 thelower Colorado River basin13 The Southwestern13 Naturalist13 28(2) 165-shy‐187

Minckley13 W L13 199113 Native fished of the Grand Canyon13 region an obituary13 Pages 124-shy‐177 in Colorado River ecology and dam13 management National Academy PressWashington13 DC

Minckley13 C13 O and M LaBarbara13 199913 Report13 on13 native fish grow-shy‐out facilities13 at Cibolaand Imperial National Wildlife Refuges 1993-shy‐199513 US Fish and13 Wildlife Service13 Parker Fishery Resources Office Parker Arizona

Modde13 T13 199613 Juvenile razorback sucker (Xyrauchen texanus) in a managed wetlandadjacent13 to the Green13 River13 Great13 Basin13 Naturalist13 56375-shy‐376

Modde T KP Burnham and E J Wick 1996 Population status of the razorback sucker13 inthe middle Green River (USA) Conservation13 biology 10 110-shy‐119

Modde13 T13 and G13 B Haines13 200513 Survival13 and growth of stocked razorback13 sucker andbonytail in multiple floodplain wetlands of the middle Green River under resetconditions13 Final report prepared for Upper Colorado13 River13 Basin RecoveryImplimentation Program US Fish and Wildlife Service Vernal 66 pp

54

13

Modde T Z H Bowen and D C Kitcheyan 2005 Spatial and temporal use of a spawning13 site in the middle Green River by wild hatchery-shy‐reared13 razorback suckers13 Transactions of the American Fisheries Society 134937-shy‐944

Mueller13 G13 199213 The native fish work13 group13 -shy‐ a multiagency endeavor to improve thestatus of the razorback sucker in Lake Mohave AZ-shy‐NV13 Proceedings of the DesertFishes Council 2369

Mueller G 1995 A program13 for maintaining the razorback sucker in Lake MohaveAmerican Fisheries Society Symposium 15127-shy‐135

Mueller13 G13 200613 Ecology of the bonytail13 and razorback13 sucker and the role of offchannelhabitats13 in their13 recovery Scientific13 investigations13 report 2006-shy‐5065 US GeologicalSurvey13 Denver

Mueller G and E Wick 1998 Testing of golf course ponds at Page Arizona for suitability13 as grow-shy‐out facility for razorback sucker using surplus fish from13 Ouray NationalFish Hatchery National Park Service US Fish and13 Wildlife13 Service and UtahDivision of Wildlife13 Resources 28 pages

Mueller13 G13 and T13 Burke13 200513 Survival13 of young13 razorback13 sucker (Xyrauchen texanus) inrelation to13 stocking rates13 (fishha)13 and13 in the presence13 or absence13 of predatorcommunities in Lake Mohave Arizona-shy‐Nevada13 Pages13 155-shy‐16313 in Proceedings of two13 symposia restoring native fish to the lower Colorado River interaction13 of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 Nevada US Fish and Wildlife13 Service Southwest Region Albuquerque New Mexico

Mueller13 G13 J13 Carpenter13 and P13 C13 Marsh13 200413 Cibola13 High Levee Pond annual report 2004US Geological Survey Fort Collins13 Science Center13 Colorado13 and Arizona StateUniversity Tempe 23 pages

Nesler T P K Christopherson J M Hudson C W McAda F Pfeifer and T E Czapla 2003An integrated stocking plan for razorback sucker bonytail and Colorado13 pikeminnow for the Upper Colorado River Endangered Fish Recovery ProgramAddendum13 to State Stocking Plans Upper Colorado River Basin Recovery13 Implementation Program 12 pp

Papoulias13 D and W13 L Minckley13 1992 Effects13 of foo availability13 on survival and growth13 of larval razorback suckers13 in ponds Transactions of the American Fisheries Society121340-shy‐355

Paukert13 C P D L Ward13 P J Sponholtz13 and K13 D Hilwig13 Effects13 of repeated hoopnetting13 on bonytail chub13 Journal of Freshwater13 Ecology13 20(4) 649-shy‐653

Pfeifer F M13 C Baker13 and M13 Montagne13 199913 Propagation13 facilities13 in the13 Grand Valley13 (24 Road13 Hatchery13 Horsethief13 Ponds and13 grow-shy‐out ponds) for captive rearing of

55

13

endangered13 fishes for the13 Upper Colorado13 River Basin13 Colorado13 River Recovery13 Program FY 99 annual project report Project No 29a13 US Fish and Wildlife Service13 Grand13 Junction13 5pp

Pfeifer F S Seversen and M Montagne 2003 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2003 annual reportProject No 29b13 US Fish and Wildlife13 Service Vernal13 4pp

Rabago-shy‐Castro J L Sanchez13 J G Perez-shy‐Castaneda R and13 Gonzalez-shy‐Gonzlez A 2006Effects of the prophylactic use of Romet-shy‐3013 and13 copper13 sulfate13 on growth13 condition13 and feeding13 indicies in13 channel13 catfish (Ictalurus punctatus) Aquaculture 253 343-shy‐349

Reinitz GL L E Orme and F N Hitzel 1979 Variations of body compositio and growth13 among strains of rainbow trout Transactions of the American Fisheries Society 108204-shy‐207

Ruppert13 J13 B P B Holden13 and P D Abate 1999 Age estimation and growth of razorbacksucker13 Xyrauchen texanus in Lake13 Mead Nevada Proceedings13 of the Desert FishesCouncil 3040

Schnoor K D and J Logan 2002 Operation and maintenance of JW Mumma nativeaquatic13 species restoration facility Colorado Colorado River Recovery Program FY2002 annual project report13 Project No 29d Colorado13 Division of Wildlife Alamosa3pp

Salisbury13 L13 1998 Factors13 affecting razorback13 sucker growth13 in Lake13 Mohave backwaters13 MS Thesis13 Unviersity13 of Nevada13 Las13 Vegas

Schooley J13 D13 and P C13 Marsh13 2007 Stocking of endangerdd13 razorback13 suckers13 in thelower Colorado River Basin13 over three decades 1974-shy‐2004 North American Journalof Fisheries Management 27 43-shy‐51

Severson S H H M Tyus and G B Haines 1992 An evaluation of feeds for raisingrazorback sucker Xyrauchen texanus Journal of Applied Aquaculture 155-shy‐65

Toney D P 1974 Observations13 on the13 propagation13 and13 rearing13 of two13 endangered species13 in a hatchery environment Proceedings of the Annual Conference of the Western13 Association of State Game and Fish Commissions 54 252-shy‐259

Tyus H M13 1998 Razorback sucker13 (Xyrauchen texanus) recovery plan13 University13 ofColorado Center for Limnology Boulder13 76 pages

Tyus H M13 and13 S H Severson 1990 Growth13 and13 survival of larval razorback suckers fedfive formulated diets The Progressive Fish Culturist 52197-shy‐200

56

13

Ulibarri M E 2003 Annual report fiscal year 2001 Dexter National Fish Hatchery13 andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 26 pages

Ulibarri M E 2003 Annual report fiscal year 2002 Dexter National Fish Hatchery andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 59 pages

USBR 2006 Lower13 Colorado13 River Multi-shy‐Species Conservation Program final fishaugmentation plan Boulder City 19 pp

USFWS 2002 Razorback sucker (Xyraouchen texanus) recovery goals Amendment andsupplement to the Razorback Sucker Recovery Plan13 US Fish and Wildlife Service13 Region 6 Denver13 Colorado

USFWS 1999 Annual report 1999 Ouray National Fish Hatchery Vernal 25pp

USFWS 2004 Management plan for the big-shy‐river13 fishes of the13 lower13 Colorado13 river basinamendment and supplement to the bonytail humpback chub Coloradopikeminnow and razorback sucker recovery plans

USFWS13 2005 Station13 profile13 of the13 Dexter13 National Fish Hatchery13 and Technology CenterUS Fish and Wildlife13 Service Dexter

Valdez R A P G Mangan R Smith and B Nilson 1982 Upper Colorado River fisheriesinvestigations13 inW H Miller J J Valentine D L Archer H M Tyus R A Valdezand L13 Kaeding13 editors13 Colorado River Fishery13 Project13 Part 2 Field13 investigations13 US Bureau of Reclamation Salt Lake City Utah

WBNFH 2004 Culture methods of the endangered razorback sucker Xyrauchen texanusUS Fish and Wildlife13 Service Willow Beach National Fish Hatchery13 8 pp

Ward D 2008 Effects of disease treatments on growth of razorback sucker ReportSubmitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 Inpartial fulfillment of work task C10 agreement number 06FG30039

Ward13 D13 M Childs and W Persons 2007 Factors13 affecting13 growth13 of razorback sucker13 (Xyrauchen texanus) in captivity Literature review and knowledge assessmentReport Submitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 In partial fulfillment of work task C10 agreement number 06FG30039

57

Appendices

Appendix 1 Survey Questions Survey of Razorback Sucker Culture in the

Southwestern United States

The enclosed survey is being distributed by the Arizona Game and Fish Department to razorback sucker culture facilities throughout

the Southwestern United States The purpose of this survey is to consolidate information regarding culture of this species so that

appropriate facility improvements can be considered for Bubbling Ponds Hatchery in Arizona Specifically we wish to increase

growth rate and production efficiency at the hatchery Information gathered in this survey will be summarized in a final report to US

Bureau of Reclamation in Boulder City NV and disseminated to all facilities that participate in the survey A workshop to discuss

the findings of this study as well as to share general information concerning razorback sucker culture will be organized by the

Arizona Game and Fish Department at the conclusion of this study and all participants will be invited

Thank you for taking the time to fill out this survey Please contact Mike Childs if you have questions or would like to discuss the

survey

Mike Childs

mchildssedonanet

(928) 639-1346

(928) 634-1279

Facility_____________________________________ Date___________________

Contact Phone _____________________________

ContactPerson_______________________________

Contact Email _______________________________

1 Water quality ranges at this culture facility

Season

Spring (Mar-May) Summer (Jun-Aug) Fall (Sept-Nov) Winter (Dec-Feb)

Temperature (C)

PH

DO (mgL)

PO4 (mgL)

TDS (mgL)

Hardness (mgL)

CaCO3

Pathogens

37

13

Effect of sorting on growth

Razorback13 suckers13 are13 currently13 sorted13 after their first13 year of growth13 They are13

typically removed from13 one of the13 upper earthen13 ponds and13 split into13 two13 lined13 ponds for

subsequent grow-shy‐out13 The larger13 fish (gt approximately 140 mm) are placed into one pond

and the smaller individuals in another It is possible that the larger fish were more

aggressive or adept13 at taking food so this sorting process is intended to allow smaller fish

to improve their growth rate

Effect of Ich on razorback sucker growth rates

We13 evaluated13 growth13 rates13 of razorback sucker13 in the13 presence13 and absence of the

ectoparasite13 Ich (Ichthiopthirus multifiliis) Ich outbreaks can occur in wild populations13 but

hatcheries13 have13 proven excellent locations13 for Ich because13 of very high fish densities13 which13

facilitate13 the13 transfer13 of Ich13 between13 fish This common fish parasite causes direct mortality13

to razorback13 suckers as well13 as secondary bacterial13 infections13

The open spring and13 ditch13 which13 provides water to the Bubbling13 Ponds Hatchery

has long13 been infested with mosquitofish (Gambusia affinis) that harbor13 the13 Ich parasite13

and allow13 it13 to enter the hatchery with incoming13 water13 The solution13 to13 the13 Ich problem13

was to remove the mosquitofish host using13 Rotenone Razorback13 sucker growth13 rates were13

then tracked in13 the absence of this parasite for 4 months and compared with growth rates

after Ich returned to the pond and from13 previous years

Methods

Razorback growth rate in lined ponds

On May 14 2008 141 razorback suckers were tagged with 12 mm PIT tags (1342

kHz) and placed in Pond 3 (approximately 1100000 gallons13 Figure13 4)13 at Bubbling13 Ponds

Fish Hatchery Fifty-shy‐three of these tags were recovered two months later when a large

Ichthyophthirius multifilis (Ich) outbreak killed many fish in the pond On October 15 2008

an additional13 145 PIT tagged13 fish were13 also placed into Pond13 3 On13 May13 14 2009 Pond13 3

was harvested and a total13 of 141 PIT tagged fish were recovered13 Of the tagged fish13 26 fish

had13 been13 in the13 pond since May13 of 2008 (378 days13 o growth) and 115 had been13 in13 the

39

13 40

pond since October13 15 2008 (211 days13 of growth) Numbers of fish in Pond 3 after the Ich

outbreak and for the majority of the period of growth were between 3 000 and 4000 fish

A Hobotempreg temperature13 logger13 was13 also13 installed13 in Pond 3 one meter below the water

surface13 near13 the13 outflow and13 recorded water temperature every 3 hours to allow analysis

of the effects of water temperature on growth rate (Figure13 5) This Hobotemp data is

representative of other pond temperatures throughout this study

In a second experiment 210 adult13 razorback suckers13 were13 PIT tagged13 on13 May 14

2009 and13 placed13 into13 Pond13 3 upper to13 evaluate13 growth13 rates13 of larger13 razorback suckers13 at

Bubbling13 Ponds Hatchery13 under current13 rearing13 conditions13 Size of these fish at tagging13

was (mean = 285 mm range = 205 ndash 396 mm) These fish remained in the pond for 257

days and were harvested on Jan 25 2010 to provide information on growth rates of larger

razorback suckers13 under13 current rearing conditions

Figure 513 Temperatures (degC) inrearing pond at BubblingPonds Hatchery from July toSept 2009 (top graph)13 andfrom Nov to Dec 2009 (Lowergraph) Temperaturesrecorded with a Hobotempregremote data logger13 every 3hours

13

Growth rate13 in an unlined pond

To document razorback sucker growth in earthen ponds we introduced13 225 tagged13

razorback suckers13 into13 Pond13 1 lower13 (Figure 4) in February 3 2010 Additional tagged fish

from13 other studies were added to the pond throughout the growing season and the density

of 1 lower reached a maximum13 of nearly 7000 fish in early summer 2010 Density was

reduced to approximately 6000 fish by capturing fish with hoop nets on June 3 2010 54 of

these fish were tagged fish and returned to 1 lower after being weighed and measured The

pond was harvested on January13 2713 2011 and a total13 of 254 tagged fish out13 of 4296 fish

total were removed from13 the pond The pond was harvested on January 27 2011 (358 days13

of growth) and the tagged fish were weighed and measured Total number of razorbacks in

the pond at harvest13 was 4296

Effect of sorting practices on growth rates

On March 1113 200913 Pond13 5 upper was13 harvested13 and13 split into13 two13 separate13 groups

Two hundred of the smaller fish (average size = 122 mm TL) were PIT tagged and placed

into13 Pond13 7 upper and13 200 of the13 larger13 fish (average = 160 mm TL) were PIT tagged and

placed int Pond13 8 upper Density13 in Pond13 7 was13 4500 fish and13 in Pond13 8 there13 were13 6500

fish These ponds were then harvested after 1 year and growth rates were compared to

give information on the effects of current sorting practices Hobotempreg temperature

loggers were installed in13 Ponds 7 and13 8 during13 the13 grow-shy‐out period with13 water13

temperature recorded every 2 hours13 (Figure13 6)

Effect of Ich on razorback sucker growth rates

Bubbling Ponds spring was treated with Rotenone (CFT Legumine 5) at a

concentration of 2 ppm13 to remove all mosquitofish from13 the spring The treatment

consisted of two treatments 6 hours in duration on two consecutive days (April 12 -shy‐ 13)

using13 drip13 stations13 and13 backpack sprayers13 followed13 by13 an13 additional 6 hours13 of

detoxification using sodium13 permanganate Although 12 mosquitofish were captured in the

spring pond the week following the treatments subsequent minnow trapping (20 traps

checked13 daily13 for 3 weeks) did not capture any additional fish until August 11 2010 when

41

13

juvenile mosquitofish were again detected in the spring pond Minnow traps have

subsequently been set daily with several hundred individuals removed To evaluate if Ich

was also again present in the spring we captured 15 mosquitofish from13 the spring pond on

three separate days and placed them13 in an aquaria at 25 degC with 5 longfin dace known to be

free of Ich These fish were monitored for 2 weeks with no signs of Ich developing This

indicates that even though mosquitofish have returned to the spring pond the parasite is no

longer present13 although how13 long13 this condition13 will13 persist13 is unknown13

On May 1113 201013 200 juvenile razorback13 suckers were harvested out13 of Pond 5

upper (2009 year Class from13 Dexter National Fish Hatchery) and were PIT tagged and

placed into Pond 8 to evaluate if growth rates at bubbling ponds hatchery have improved

following the renovation of the spring and the removal of the Ich parasite Unfortunately13

on Sept13 8 2010 Ich was13 again13 detected13 in Pond 8 and the pond was immediately seined

and 74 tagged fish were measured to obtain growth information for the 4-shy‐month period

during13 which13 the13 pond13 was13 Ich-shy‐free13

Figure13 6 Temperatures (degC) in rearingponds 7 and 8 at Bubbling Ponds Hatchery13 from March 2009 ndash March 201013 pond 7(top13 graph)13 and13 pond 8 (Lower13 graph)13 Temperatures recorded with a Hobotempregremote data logger every 3 hours

42

13

Results

Growth in Lined Ponds

Razorback suckers13 that had been13 in13 Pond 8 upper for the13 entire13 year13 grew an13

average of 0263 mmday (789 mmmonth) and razorback suckers that had been in the

pond for 7 months (Oct -shy‐ May) grew13 on13 average of 028 mmday (843 mmmonth) (Figure13

7) These growth13 rates13 did not significantly13 differ Fish density13 in Pond 3 during13 the13

majority of the growth period was13 00032 ndash 00036 fishgallon13 Additionally no13 significant

differences in growth rate were observed between fish smaller than 210 mm TL and fish

larger than 210 mm TL when all recaptured fish were combined

We also measured the growth rate of very large fish in a lined pond On Jan13 2513 201013

156 adult fish with PIT tags were recovered from13 Pond 3 upper13 These fish were13 in the13

pond for 257 days and experienced an average13 growth13 rate13 of 024mmday or 73

mmmonth (Figure13 7)13 This growth13 rate13 is slightly13 lower13 than13 the13 average13 growth13 rate13

observed13 at Bubbling13 Ponds Hatchery in other studies (0275 mmday 825 mmmonth)

but may not be biologically meaningful We would expect larger13 fish to13 have13 reduced

growth rates according to a typical Von Bertalanfy growth model (Bertalanffy 1957) but it

appears that13 over the size range we evaluated (300 -shy‐ 450 mm TL) growth rates have not

slowed significantly compared to that of smaller13 fish grown at Bubbling Ponds13 Hatchery

Growth13 of razorback suckers13 is known13 to13 slow as13 fish reach13 larger13 sizes but it appears13 this13

reduced growth rate may not really start to be biologically meaningful at Bubbling Ponds

Hatchery13 until razorback suckers13 exceed 450 mm TL

Growth in unlined ponds

Growth13 rates13 for the13 fish recaptured13 during13 the Pond 1 lower13 thinning13 (120 days13 in

the pond) was 024 plusmn 003 mmday (729 plusmn 090 mmmonth) (Figure13 8)13 Fish13 that were13 in

the pond for nearly the entire year grew13 an13 average13 of 024 plusmn 001 mmday (726 plusmn 027

mmmonth) These growth rates are surprisingly the lowest measured growth rates for

any part of our study and differ significantly from13 every other measured growth rate

except very large13 fish (Figure13 9)13 Separating13 out13 large fish that13 were in13 the pond for the

entire year makes no difference fish that were added to the pond at TL lt300 mm grew

43

13

Gro

wth

Rat

e (m

md

ay)

020

026

032

0244 plusmn 001 mmday (733 plusmn 028 mmmonth) and and those with TL gt= 300 mm at the

start of the experiment grew 022 plusmn 003 mmday (651 plusmn 101 mmmonth)

Razorback Growth Rates in Lined Ponds

Figure 7 Growth ofrazorback suckers in(mmday plusmn standard error)in Pond 8 upper in 2008-shy‐2009 An ANOVA did notdetect any significantdifferences

7 Months Full Year 300+ mm fish

Effects of sorting on growth

One hundred and seventy five tagged razorback suckers were recovered from13 Pond

8 upper13 on March13 24 2010 (378 days13 of growth)13 These were13 the13 larger sorted13 fish (gt140

mm TL) that came out of Pond13 5 on March13 11 2009 One13 hundred and13 twenty13 two13 tagged13

razorback suckers were also recovered from13 Pond13 7 upper on March13 31 2010 (385 days13 of

growth)13 These were13 the13 smaller sorted13 fish (lt140 mm TL) that came out of Pond13 5 on

March 1113 200913 No significant differences in growth rate (mmday) were observed among

larger fish in Pond 8 and smaller fish in Pond 7 (pgt005 ANOVA) (Figure 10)13 indicating

that13 sorting may have helped to offset the original slower growth trajectory of the smaller

fish Temperatures of Ponds 7 and 8 upper remained similar throughout the year13 (Figure

5)

44

13

13

13

Gro

wth

Rat

e (m

md

ay)

Gro

wth

Rat

e (m

md

ay)

020

026

032

020

026

032

Razorback Growth in an Unlined Pond

Figure 8 Growth of razorbacksuckers (mmday plusmn standard error) in Pond 1 lower (an unlined pond)in 2010-shy‐2011 An ANOVA did notdetect any significant differences

6 Months 12 Months lt 300 mm Fish 300+ mm Fish Growth Growth

Lined vs Earthen Ponds 1 year of growth

Figure 9 Growth of razorbacksuckers (mmday plusmn standard error) in lined and unlined ponds A t-shy‐test13 did not detect a significantdifference

Lined Pond Unlined Pond 1 Yr Growth 1 Yr Growth

45

13

Effect of Sorting G

row

th R

ate

(mm

day

) G

row

th R

ate

(mm

day

)

032

020

026

032

020

026

Smaller Fish Larger Fish

Effect of Ich

Figure 10 Average growthof razorback suckers(mmday plusmn standard error)that were size-shy‐sorted intosmall fish (pond 7) and largefish (pond 8) populations At-shy‐test did not detect asignificant difference

Figure 11 Average growth ofrazorback suckers (mmday plusmnstandard error) after Ich wasremovd from the hatcheryrsquos springand after Ich was again detected inthe pond The growth rate withoutIch is significantly higher than boththe rate after Ich and the ourstudyrsquos average annual growth ratein lined ponds (ANOVA p =00003)

Growth without Ich Growth With Ich Average Annual 4 months 4 months Growth Rate

46

13

Effect of Ich on razorback sucker growth rates

Seventy-shy‐four13 tagged13 razorback suckers13 were13 recovered from13 Pond 8 on September

15 2010 These fish had13 been13 in the pond for 4 months and experienced a growth rate of

032 mmday or 97 mmmonth (Figure13 11)13 This growth13 rate13 is significantly higher (p =

005 two sample t-shy‐test) than the mean growth rate for the same group13 of tagged fish after

Ich detection (022 mmday or 65 mmmonth) and significantly higher than any other

individual growth13 rates13 observed13 to13 date13 at Bubbling13 Ponds Hatchery13 (Figure13 11)13 If this13

growth13 rate13 were13 extended throughout13 the entire13 year13 fish on average from13 Ich-shy‐free13 ponds13

would be 16 mm longer than fish from13 ponds infested with Ich Studies conducted at

Bubbling Ponds hatchery in 2008 (Ward 2008) did not reveal any effects of the treatment

chemicals on razorback sucker growth rates so it13 is likely that13 the parasite outbreaks

themselves are causing reducing growth rates rather than the chemicals used to treat the

parasites13

Conclusions

Our results suggest that under typical hatchery operations (maximizing number of

fish produced)13 the growth13 rate13 of razorback13 suckers13 is relatively13 consistent at Bubbling13

Ponds hatchery13 at 02-shy‐03 mmday (6-shy‐9 mmmonth)13 but is lower than growth13 rates13 at

other13 facilities (02 ndash 18 mmday Ward et al 2007)13 This growth13 rate13 has13 been13 constant in

both lined and unlined ponds and at all fish densities we were able to measure To achieve13

growth13 rates13 substantially higher than this will likely require13 significant changes in rearing

practices that may not be practical in order to reach numerical production13 goals

Temperature is a key variable in fish growth but seasonal growth patterns

described13 above13 (Figure13 5) demonstrate that water temperatures are high enough in

winter to maintain razorback growth Differences in water temperature by season

currently13 do not fluctuate more than 10degC at Bubbling Ponds because of the continuous

supply of water flowing through each pond (approx 225 gallonsmin) These high water

flows appear to keep pond temperatures within the thermal preference13 for razorback

suckers13 (1213 -shy‐ 28 degC Bulkley and Pimentel 1983) throughout the entire year with

temperatures rarely dropping13 below 16deg13 C (Figures 513 6)13

47

13

Fish density is another key variable in fish growth and though the number of fish in

a pond during our study ranged from13 3000 to 700013 fish we13 did not find any13 correlation13

between13 density and growth rate13 This might yield two conclusions First13 razorback

growth13 may be changed equally13 by13 densities13 at the13 hatchery13 (ie13 a density13 of 3000 fish in a

pond is as stressful13 for razorbacks as a density13 of 7000 fish) An alternative is that other

factors13 such as disease outbreaks have13 stronger13 control over fish growth13 than13 density13

Fish density13 would13 have13 to13 be13 experimentally manipulated to test13 this13 and hatchery

operations (producing the maximum13 number of fish) prevented our manipulating density13

in ponds for this13 work The trouble with manipulating density demonstrates the difficulties

associated with changing13 hatchery13 practices experimenting with density would have

prevented BPH from13 meeting13 production13 goals Given that the stocking of smaller

razorbacks has met with very little success perhaps BPH goals could be changed from13

producing 12000 fish at 300+ mm per year to a smaller number of very large fish each

year Growing13 fewer13 larger13 fish could potentially be accomplished in the same time frame

as more smaller fish but a better understanding of how density alters growth rate would

be required to be confident13 of this

The very slow growth13 in the13 earthen13 unlined13 Pond 1 lower13 was very surprising We13

had13 anticipated13 that the13 diversified diet13 cover and13 other13 habitat features13 provided by13

unlined ponds would yield dramatically increased growth rates However these traits were

not enough to offset high fish densities and in fact the unlined pond in our study13 suffered

mortality to bring densities down to that observed normally in lined ponds

Our data13 suggest13 that razorbacks13 sucker13 growth13 rates13 are13 higher in lined13 ponds13

However we13 think the reasons13 for the13 very slow growth we observed13 in the13 unlined13 pond13

in our study13 is instead13 linked13 to13 the13 usage13 of Pond 1 lower13 during13 the13 study13 rather13 than13

intrinsic13 slow growth13 in earthen13 ponds First the pond was at extremely high density for at

least part of the study The volume of Pond 1 lower has not been estimated but hatchery

managers suggest 1500-shy‐2000 fish is an appropriate number of individuals so this pond

was at a very high density for much of the experiment Second dissolved oxygen is often

very low in the13 large13 earthen13 ponds during the heat of summer much lower than that of

lined ponds This will both limit the number of fish that can survive in the pond and almost

certainly13 increases stress13 of these13 fish potentially13 reducing growth13 The DO crashes also13

48

13

limit the amount of feed hatchery managers can give fish in these ponds sometimes for

days or weeks at a time which further reduces growth during warm13 weather

Our data13 suggests that13 growth rates at the Bubbling13 Ponds Fish Hatchery are likely

as high as possible given13 the pond densities required to meet production goals and the Ich-shy‐

infested water that feeds the facility Sorting practices are successful in helping as many

fish as possible reach stocking length as fast as possible Unlined ponds may be able to

grow13 large13 fish at low13 densities13 but whatever factors allow13 for that13 growth are not13 able to

overcome high fish density The removal of invasive13 fis that act as13 a host for the13 parasite13

Ich fish from13 the Bubbling13 Ponds spring13 allowed the highest13 growth rate at 032 mmday13

(96 mmmonth) but that growth rate decreased again as Ich re-shy‐infested13 the13 hatchery13

Consistently13 achieving13 growth13 rates13 as high or substantially13 higher than13 this13 will likely13

require13 significant changes in rearing practices that may not be practical in order to13 reach13

numerical production13 goals

Two major changes that might result in higher growth rates are substantially

reducing fish density and modifying the way spring water is delivered to the facility (via

either repeated chemical treatments or enclosed concrete water diversions) to eliminate

Ich from13 the hatchery source water Other potential changes not address by our work

include13 flow-shy‐training razorbacks much previous literature including MSCP-shy‐funded13 work

on razorback suckers13 suggests13 that fish growing13 in flowing water will grow13 faster than fish

in still water (Jorgensen and Jobling 1994) Furthermore there are a wide variety of

potential benefits associated with growing13 fish13 in flowing13 water in addition13 to increased

growth13 rates13 (Davidson13 199713 Castro13 et al13 2011) Another option13 for increasing13 growth13

rates13 include13 changing to13 intensive13 culture13 in large circular13 tanks

Finally given that the stocking of smaller razorbacks has met with very little

success13 perhaps13 BPH13 goals13 could13 be13 changed from13 producing 12000 fish at 300+ mm per

year to a smaller number of very large fish each year Growing fewer larger fish could

potentially be accomplished in the same time frame as more smaller fish but a better

understanding13 of how density13 alters growth13 rate13 would13 be13 required to13 be13 confident of this

49

13

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower13 Colorado13 River Multi-shy‐Species13

Conservation Program13 (LCRMSCP) under Work Task C10 We13 thank Ty Wolters13 Tom13

Burke13 and Eric13 Volkman for their support of this research and Frank Agygos and Dave

Billingsly13 of the Bubbling13 Ponds Fish Hatchery13 for their willingness to participate in13 this

research13 and13 for their technical assistance We also thank the LCRMSCP fish group from13

Boulder City13 NV for their assistance with harvesting13 ponds and tagging13 fish13

50

13

Literature13 CitedAnders P J 1998 Conservation aquaculture and endangered species can objective science13

prevail13 over risk13 anxiety Fisheries 23(11) 28-shy‐31

Anderson R O and R M Nuemann 1996 Length weight and associated structural indicesPages 447 ndash 482 in B R Murphy13 and D13 W Willis13 editors13 Fisheries techniques13 2ndedtion American Fisheries13 Society13 Bethesda13 Maryland

Bain M B J T Finn and H E Brooks 1988 Streamflow regulation and fish communitystructure13 Ecology13 69382-shy‐392

Bays J H Zarbock R Whitman and T Murphy 2005 Conceptual design and managementof native13 fish refugia on the13 lower13 Colorado13 River In13 CL Spring13 and13 S Leoneditors Proceedings of two symposia Restoring native fish to the lower ColoradoRiver13 interactions13 of native and non-shy‐native13 fishes 13ndash1413 July13 1999 Las13 Vegas13 Nevada13 Restoring13 natural function within a modified riverine environment thelower Colorado River13 8ndash913 July13 1998 U S Fish and13 Wildlife13 Service Southwestern13 Region Albuquerque New Mexico Pages 167-shy‐177

Bertalanffy L Von 1957 Quantitative laws in metabolism13 and growth13 Q Rev Biology 32217 ndash 231

Bingham T B Scheer and C McAda 2003 Propagation facilities in Grand Valley (24 RoadHatchery Horsethief13 Ponds and13 grow-shy‐out ponds) for captive13 rearing13 ofendangered13 fishes for the13 upper13 Colorado13 River basin13 Colorado River RecoveryProgram FY2003 annual project report13 US Fish and13 Wildlife13 Service GrandJunction13 4pp

Birchell G J and K Christopherson 2004 Survival growth and recruitment of larval andjuvenile razorback13 sucker (Xyrauchen texanus) introduced13 into13 floodplain13 depressions13 of the13 Green River Utah13 Final report13 Upper13 Colorado13 RiverEndangered Fish Recovery Program13 Project No C-shy‐6RZ Publication Number 04-shy‐1513 Utah13 Division of Wildlife13 Resources Salt Lake13 City13 Utah13 67 pages

Brannon E L 1993 The perpetual oversight of hatchery programs Fishery Research 1819-shy‐27

Brett J R 1979 Environmental Factors and growth pages 599-shy‐67513 InW S Hoar13 D13 J13 Randall and J R Brett (eds) Fish Physiology Volume 8 Bioenergetics and GrowthAcademic Press New York

Brooks J E 1986 Annual reintroduction and monitoring report for razorback suckerXyrauchen texanus in the Gila River Basin Arizona 1985 US Fish and WildlifeService13 Offices of Endangered13 Species and Fishery13 Resources Albuquerque 23 pp

51

13

Brunson13 R E and K D13 Christopherson13 200513 Larval13 razorback13 sucker and bonytailsurvival and13 growth13 in the13 presence13 of nonnative13 fish in the13 Baeser13 floodplainwetland of the middle Green River Final report prepared for Upper13 Colorado RiverBasin Endangered Fish Recovery Program Project No C-shy‐6-shy‐rz-shy‐bt Publication13 No 05-shy‐26 Utah13 Division of Wildlife13 Resources13 Vernal13 32 pp

Bulkley R V and R Pimentel 1983 Temperature preference and avoidance by adultrazorback suckers Transactions of the American Fisheries Society 112601-shy‐607

Burke13 T13 199513 Rearing13 wild razorback13 sucker larvae in13 lake-shy‐side13 backwaters13 LakeMohave ArizonaNevada Proceedings of the Desert Fishes Council 2635

Busacker G P I R Adelman and E M Goolish13 199013 Growth13 Pages 363 ndash 387 in C BSchreck and p B Moyle editors Methods for fish biology American FisheriesSociety Bethesda Maryland

Castro V B Grisdale-shy‐Helland S J Helland T Kristensen S M Jorgensen J Helgrud13 GClaireaux A P Farrell A Krasnov and H Takle 2011 Aerobic training stimulatesgrowth and promotes disease resistance in Atlantic salmon (Salmo salar)Comparative Biochemistry and Physiology -shy‐ Part A Molecular amp IntegrativePhysiology13 160(2) 278-shy‐290

Czapla T E 2002 Facilities plan for the production of endangered fishes to meet statestocking13 plans13 as13 part of the13 Upper13 Colorado13 River Endangered13 Fish RecoveryProgram Upper Colorado River Basin Recovery Implementation Program US Fishand Wildlife Service13 Denver13 9 pp

Davidson W 1997 The effects13 of exercise13 training on teleost fish a review of recentliterature Comput Biochem Physiol 117A67ndash75

Figiel Jr C R 2005 Annual report fiscal year 2004 Willow Beach National13 Fish HatcheryUS Fish and Wildlife13 Service Willow Beach 17 pp

Figiel Jr C R M E Ulibarri G Carmichael J Seals and J N Hanson 2005 Intensive13 fish13 culture of warmwater native fishes at a coldwater fish hatchery Pages 164-shy‐16613 inProceedings of two symposia restoring native fish to the lower Colorado13 River13 interaction13 of native13 and13 non-shy‐native13 fishes July13 13-shy‐1413 1999 Las Vegas Nevada USFish and Wildlife Service Southwest Region Albuquerque New Mexico

Gerking13 S D 1978 Ecology of freshwater fish13 production13 Halstead Press13 New13 York

Gustafson W and Q Bradwisch 2000 Wahweap operation and maintenance -shy‐-shy‐ UtahColorado River Recovery Program FY 2000 annual project report Project No 29cUtah13 Division of Wildlife13 Resources Page AZ 3pp

52

13

Hamman R L 1985 Induced spawning of hatchery-shy‐reared13 razorback sucker ProgressivFish Culturist 47(3) 187-shy‐189

Hanson J N 1996 Annual report fiscal year 1996 Willow Beach National Fish HatcheryUS Fish and Wildlife Service13 Willow Beach 9pp

Irving D S Seversen and M Montagne 2004 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2004 annual project13 report Report No 29b US Fish and13 Wildlife13 Service Vernal 3pp

Jorgensen E H and13 M Jobling 1994 Feeding and13 growth13 of exercised13 and13 unexercised13 juvenile Atlantic salmon in freshwater and performance after transfer to seawaterAquaculture International 2 154-shy‐164

Kaeding L R and D B Osmundson 198913 Colorado13 Squawfish13 and13 razorback sucker grow-shy‐out pond studies as part of conservation measures for the green mountain andRuedi reservoir water sales Final report for agreement number 6-shy‐AA-shy‐60-shy‐00150

Koebele13 B P13 198513 Growth and the size hierarchy effect an experimental assessment ofthree proposed mechanisms activity differences disproportional food acquisition13 pysiological stress Environmental Biology of Fishes 12 181-shy‐188

Kretschmann A E and L L Leslie 2006 Razorback sucker (Xyrauchen texanus) status13 reproduction and recruitment in Senator Wash Reservoir CA Final Report13 to USBurea of Reclamation Cooperative Agreement No 00-shy‐FG-shy‐34-shy‐ 0009 p 32 ArizonaGame and Fish Department Phoenix

Marsh13 P13 C13 1987a13 Digestive tract13 contents13 of adult razorback suckers13 in Lake13 MohaveArizona-shy‐Nevada Transactions of the American Fisheries Society 116117-shy‐119

Marsh P C 1987b Native fishes at Buenos Aires National Wildlife Refuge and ArizonaState University Research Park Arizona opportunities for management researchand public13 education13 on13 endangered species13 Proceedings of the Desert13 FishesCouncil 1967-shy‐78

Marsh P C 1994 Rearing native Colorado River fishes in golf course ponds Arizona StateUniversity Tempe 22 + pages

Marsh13 P13 C13 200013 Fish population13 status and evaluation13 in13 the Cibola13 High Levee PondFinal report agreement number 99-shy‐FG-shy‐30-shy‐00051 US Bureau of ReclamationBoulder City13 Nevada13 20 pages

Marsh P C and C A Pacey 1998 Growth of wild adult razorback suckers13 in Lake13 Mohave13 Arizona-shy‐Nevada13 Final report13 US Bureau of Reclamation Boulder City Nevada 25pages + appendices

53

13

Marsh P C B R Kesner and C A Pacey 2005 Repatriation as s management strategy13 to13 conserve a critically13 imperiled fish species North American Journal of FisheriesManagement 25 547-shy‐556

Marsh P C and C A Pacey 2005 Immiscibility of native and non-shy‐native13 fishes Pages 59-shy‐63 inMJ13 Brouder13 CL13 Springer13 and CS13 Leon13 editors13 Proceedings of two13 symposia Restoring native fish to the lower Colorado River interactions of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 NV and13 Restoring natural13 function within a modified riverine environment the lower Colorado River13 July13 8-shy‐913 1998 Las Vegas NV US Fish and13 Wildlife13 Service Southwest Region AlbuquerqueNew Mexico

Marsh13 P13 C13 and J13 E Brooks13 198913 Predation13 by ictalurid catfishes as a deterrent13 toreestablishment of hatchery-shy‐reared13 razorback sucker The Southwestern Naturalist34188-shy‐195

Matthews R A 2005 Ichthyopthirus multifiliis Fouquet and Ichthyopthirosis infreshwater13 teleosts13 Pages13 159-shy‐218 in Advances in Parasitology volume 59 J RBaker R Muller D Rollinson (eds) Academic Press

McCarthy13 M S and W L Minckley 1987 Age estimation for razorback sucker (PiscesCatostomidae) from13 Lake Mohave Arizona and Nevada Journal of the Arizona-shy‐Nevada Academy of Science 2187-shy‐97

Minckley13 W L13 198313 Status of the razorback13 sucker13 Xyrauchen texanus (Abbot)13 in13 thelower Colorado River basin13 The Southwestern13 Naturalist13 28(2) 165-shy‐187

Minckley13 W L13 199113 Native fished of the Grand Canyon13 region an obituary13 Pages 124-shy‐177 in Colorado River ecology and dam13 management National Academy PressWashington13 DC

Minckley13 C13 O and M LaBarbara13 199913 Report13 on13 native fish grow-shy‐out facilities13 at Cibolaand Imperial National Wildlife Refuges 1993-shy‐199513 US Fish and13 Wildlife Service13 Parker Fishery Resources Office Parker Arizona

Modde13 T13 199613 Juvenile razorback sucker (Xyrauchen texanus) in a managed wetlandadjacent13 to the Green13 River13 Great13 Basin13 Naturalist13 56375-shy‐376

Modde T KP Burnham and E J Wick 1996 Population status of the razorback sucker13 inthe middle Green River (USA) Conservation13 biology 10 110-shy‐119

Modde13 T13 and G13 B Haines13 200513 Survival13 and growth of stocked razorback13 sucker andbonytail in multiple floodplain wetlands of the middle Green River under resetconditions13 Final report prepared for Upper Colorado13 River13 Basin RecoveryImplimentation Program US Fish and Wildlife Service Vernal 66 pp

54

13

Modde T Z H Bowen and D C Kitcheyan 2005 Spatial and temporal use of a spawning13 site in the middle Green River by wild hatchery-shy‐reared13 razorback suckers13 Transactions of the American Fisheries Society 134937-shy‐944

Mueller13 G13 199213 The native fish work13 group13 -shy‐ a multiagency endeavor to improve thestatus of the razorback sucker in Lake Mohave AZ-shy‐NV13 Proceedings of the DesertFishes Council 2369

Mueller G 1995 A program13 for maintaining the razorback sucker in Lake MohaveAmerican Fisheries Society Symposium 15127-shy‐135

Mueller13 G13 200613 Ecology of the bonytail13 and razorback13 sucker and the role of offchannelhabitats13 in their13 recovery Scientific13 investigations13 report 2006-shy‐5065 US GeologicalSurvey13 Denver

Mueller G and E Wick 1998 Testing of golf course ponds at Page Arizona for suitability13 as grow-shy‐out facility for razorback sucker using surplus fish from13 Ouray NationalFish Hatchery National Park Service US Fish and13 Wildlife13 Service and UtahDivision of Wildlife13 Resources 28 pages

Mueller13 G13 and T13 Burke13 200513 Survival13 of young13 razorback13 sucker (Xyrauchen texanus) inrelation to13 stocking rates13 (fishha)13 and13 in the presence13 or absence13 of predatorcommunities in Lake Mohave Arizona-shy‐Nevada13 Pages13 155-shy‐16313 in Proceedings of two13 symposia restoring native fish to the lower Colorado River interaction13 of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 Nevada US Fish and Wildlife13 Service Southwest Region Albuquerque New Mexico

Mueller13 G13 J13 Carpenter13 and P13 C13 Marsh13 200413 Cibola13 High Levee Pond annual report 2004US Geological Survey Fort Collins13 Science Center13 Colorado13 and Arizona StateUniversity Tempe 23 pages

Nesler T P K Christopherson J M Hudson C W McAda F Pfeifer and T E Czapla 2003An integrated stocking plan for razorback sucker bonytail and Colorado13 pikeminnow for the Upper Colorado River Endangered Fish Recovery ProgramAddendum13 to State Stocking Plans Upper Colorado River Basin Recovery13 Implementation Program 12 pp

Papoulias13 D and W13 L Minckley13 1992 Effects13 of foo availability13 on survival and growth13 of larval razorback suckers13 in ponds Transactions of the American Fisheries Society121340-shy‐355

Paukert13 C P D L Ward13 P J Sponholtz13 and K13 D Hilwig13 Effects13 of repeated hoopnetting13 on bonytail chub13 Journal of Freshwater13 Ecology13 20(4) 649-shy‐653

Pfeifer F M13 C Baker13 and M13 Montagne13 199913 Propagation13 facilities13 in the13 Grand Valley13 (24 Road13 Hatchery13 Horsethief13 Ponds and13 grow-shy‐out ponds) for captive rearing of

55

13

endangered13 fishes for the13 Upper Colorado13 River Basin13 Colorado13 River Recovery13 Program FY 99 annual project report Project No 29a13 US Fish and Wildlife Service13 Grand13 Junction13 5pp

Pfeifer F S Seversen and M Montagne 2003 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2003 annual reportProject No 29b13 US Fish and Wildlife13 Service Vernal13 4pp

Rabago-shy‐Castro J L Sanchez13 J G Perez-shy‐Castaneda R and13 Gonzalez-shy‐Gonzlez A 2006Effects of the prophylactic use of Romet-shy‐3013 and13 copper13 sulfate13 on growth13 condition13 and feeding13 indicies in13 channel13 catfish (Ictalurus punctatus) Aquaculture 253 343-shy‐349

Reinitz GL L E Orme and F N Hitzel 1979 Variations of body compositio and growth13 among strains of rainbow trout Transactions of the American Fisheries Society 108204-shy‐207

Ruppert13 J13 B P B Holden13 and P D Abate 1999 Age estimation and growth of razorbacksucker13 Xyrauchen texanus in Lake13 Mead Nevada Proceedings13 of the Desert FishesCouncil 3040

Schnoor K D and J Logan 2002 Operation and maintenance of JW Mumma nativeaquatic13 species restoration facility Colorado Colorado River Recovery Program FY2002 annual project report13 Project No 29d Colorado13 Division of Wildlife Alamosa3pp

Salisbury13 L13 1998 Factors13 affecting razorback13 sucker growth13 in Lake13 Mohave backwaters13 MS Thesis13 Unviersity13 of Nevada13 Las13 Vegas

Schooley J13 D13 and P C13 Marsh13 2007 Stocking of endangerdd13 razorback13 suckers13 in thelower Colorado River Basin13 over three decades 1974-shy‐2004 North American Journalof Fisheries Management 27 43-shy‐51

Severson S H H M Tyus and G B Haines 1992 An evaluation of feeds for raisingrazorback sucker Xyrauchen texanus Journal of Applied Aquaculture 155-shy‐65

Toney D P 1974 Observations13 on the13 propagation13 and13 rearing13 of two13 endangered species13 in a hatchery environment Proceedings of the Annual Conference of the Western13 Association of State Game and Fish Commissions 54 252-shy‐259

Tyus H M13 1998 Razorback sucker13 (Xyrauchen texanus) recovery plan13 University13 ofColorado Center for Limnology Boulder13 76 pages

Tyus H M13 and13 S H Severson 1990 Growth13 and13 survival of larval razorback suckers fedfive formulated diets The Progressive Fish Culturist 52197-shy‐200

56

13

Ulibarri M E 2003 Annual report fiscal year 2001 Dexter National Fish Hatchery13 andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 26 pages

Ulibarri M E 2003 Annual report fiscal year 2002 Dexter National Fish Hatchery andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 59 pages

USBR 2006 Lower13 Colorado13 River Multi-shy‐Species Conservation Program final fishaugmentation plan Boulder City 19 pp

USFWS 2002 Razorback sucker (Xyraouchen texanus) recovery goals Amendment andsupplement to the Razorback Sucker Recovery Plan13 US Fish and Wildlife Service13 Region 6 Denver13 Colorado

USFWS 1999 Annual report 1999 Ouray National Fish Hatchery Vernal 25pp

USFWS 2004 Management plan for the big-shy‐river13 fishes of the13 lower13 Colorado13 river basinamendment and supplement to the bonytail humpback chub Coloradopikeminnow and razorback sucker recovery plans

USFWS13 2005 Station13 profile13 of the13 Dexter13 National Fish Hatchery13 and Technology CenterUS Fish and Wildlife13 Service Dexter

Valdez R A P G Mangan R Smith and B Nilson 1982 Upper Colorado River fisheriesinvestigations13 inW H Miller J J Valentine D L Archer H M Tyus R A Valdezand L13 Kaeding13 editors13 Colorado River Fishery13 Project13 Part 2 Field13 investigations13 US Bureau of Reclamation Salt Lake City Utah

WBNFH 2004 Culture methods of the endangered razorback sucker Xyrauchen texanusUS Fish and Wildlife13 Service Willow Beach National Fish Hatchery13 8 pp

Ward D 2008 Effects of disease treatments on growth of razorback sucker ReportSubmitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 Inpartial fulfillment of work task C10 agreement number 06FG30039

Ward13 D13 M Childs and W Persons 2007 Factors13 affecting13 growth13 of razorback sucker13 (Xyrauchen texanus) in captivity Literature review and knowledge assessmentReport Submitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 In partial fulfillment of work task C10 agreement number 06FG30039

57

Appendices

Appendix 1 Survey Questions Survey of Razorback Sucker Culture in the

Southwestern United States

The enclosed survey is being distributed by the Arizona Game and Fish Department to razorback sucker culture facilities throughout

the Southwestern United States The purpose of this survey is to consolidate information regarding culture of this species so that

appropriate facility improvements can be considered for Bubbling Ponds Hatchery in Arizona Specifically we wish to increase

growth rate and production efficiency at the hatchery Information gathered in this survey will be summarized in a final report to US

Bureau of Reclamation in Boulder City NV and disseminated to all facilities that participate in the survey A workshop to discuss

the findings of this study as well as to share general information concerning razorback sucker culture will be organized by the

Arizona Game and Fish Department at the conclusion of this study and all participants will be invited

Thank you for taking the time to fill out this survey Please contact Mike Childs if you have questions or would like to discuss the

survey

Mike Childs

mchildssedonanet

(928) 639-1346

(928) 634-1279

Facility_____________________________________ Date___________________

Contact Phone _____________________________

ContactPerson_______________________________

Contact Email _______________________________

1 Water quality ranges at this culture facility

Season

Spring (Mar-May) Summer (Jun-Aug) Fall (Sept-Nov) Winter (Dec-Feb)

Temperature (C)

PH

DO (mgL)

PO4 (mgL)

TDS (mgL)

Hardness (mgL)

CaCO3

Pathogens

37

13 40

pond since October13 15 2008 (211 days13 of growth) Numbers of fish in Pond 3 after the Ich

outbreak and for the majority of the period of growth were between 3 000 and 4000 fish

A Hobotempreg temperature13 logger13 was13 also13 installed13 in Pond 3 one meter below the water

surface13 near13 the13 outflow and13 recorded water temperature every 3 hours to allow analysis

of the effects of water temperature on growth rate (Figure13 5) This Hobotemp data is

representative of other pond temperatures throughout this study

In a second experiment 210 adult13 razorback suckers13 were13 PIT tagged13 on13 May 14

2009 and13 placed13 into13 Pond13 3 upper to13 evaluate13 growth13 rates13 of larger13 razorback suckers13 at

Bubbling13 Ponds Hatchery13 under current13 rearing13 conditions13 Size of these fish at tagging13

was (mean = 285 mm range = 205 ndash 396 mm) These fish remained in the pond for 257

days and were harvested on Jan 25 2010 to provide information on growth rates of larger

razorback suckers13 under13 current rearing conditions

Figure 513 Temperatures (degC) inrearing pond at BubblingPonds Hatchery from July toSept 2009 (top graph)13 andfrom Nov to Dec 2009 (Lowergraph) Temperaturesrecorded with a Hobotempregremote data logger13 every 3hours

13

Growth rate13 in an unlined pond

To document razorback sucker growth in earthen ponds we introduced13 225 tagged13

razorback suckers13 into13 Pond13 1 lower13 (Figure 4) in February 3 2010 Additional tagged fish

from13 other studies were added to the pond throughout the growing season and the density

of 1 lower reached a maximum13 of nearly 7000 fish in early summer 2010 Density was

reduced to approximately 6000 fish by capturing fish with hoop nets on June 3 2010 54 of

these fish were tagged fish and returned to 1 lower after being weighed and measured The

pond was harvested on January13 2713 2011 and a total13 of 254 tagged fish out13 of 4296 fish

total were removed from13 the pond The pond was harvested on January 27 2011 (358 days13

of growth) and the tagged fish were weighed and measured Total number of razorbacks in

the pond at harvest13 was 4296

Effect of sorting practices on growth rates

On March 1113 200913 Pond13 5 upper was13 harvested13 and13 split into13 two13 separate13 groups

Two hundred of the smaller fish (average size = 122 mm TL) were PIT tagged and placed

into13 Pond13 7 upper and13 200 of the13 larger13 fish (average = 160 mm TL) were PIT tagged and

placed int Pond13 8 upper Density13 in Pond13 7 was13 4500 fish and13 in Pond13 8 there13 were13 6500

fish These ponds were then harvested after 1 year and growth rates were compared to

give information on the effects of current sorting practices Hobotempreg temperature

loggers were installed in13 Ponds 7 and13 8 during13 the13 grow-shy‐out period with13 water13

temperature recorded every 2 hours13 (Figure13 6)

Effect of Ich on razorback sucker growth rates

Bubbling Ponds spring was treated with Rotenone (CFT Legumine 5) at a

concentration of 2 ppm13 to remove all mosquitofish from13 the spring The treatment

consisted of two treatments 6 hours in duration on two consecutive days (April 12 -shy‐ 13)

using13 drip13 stations13 and13 backpack sprayers13 followed13 by13 an13 additional 6 hours13 of

detoxification using sodium13 permanganate Although 12 mosquitofish were captured in the

spring pond the week following the treatments subsequent minnow trapping (20 traps

checked13 daily13 for 3 weeks) did not capture any additional fish until August 11 2010 when

41

13

juvenile mosquitofish were again detected in the spring pond Minnow traps have

subsequently been set daily with several hundred individuals removed To evaluate if Ich

was also again present in the spring we captured 15 mosquitofish from13 the spring pond on

three separate days and placed them13 in an aquaria at 25 degC with 5 longfin dace known to be

free of Ich These fish were monitored for 2 weeks with no signs of Ich developing This

indicates that even though mosquitofish have returned to the spring pond the parasite is no

longer present13 although how13 long13 this condition13 will13 persist13 is unknown13

On May 1113 201013 200 juvenile razorback13 suckers were harvested out13 of Pond 5

upper (2009 year Class from13 Dexter National Fish Hatchery) and were PIT tagged and

placed into Pond 8 to evaluate if growth rates at bubbling ponds hatchery have improved

following the renovation of the spring and the removal of the Ich parasite Unfortunately13

on Sept13 8 2010 Ich was13 again13 detected13 in Pond 8 and the pond was immediately seined

and 74 tagged fish were measured to obtain growth information for the 4-shy‐month period

during13 which13 the13 pond13 was13 Ich-shy‐free13

Figure13 6 Temperatures (degC) in rearingponds 7 and 8 at Bubbling Ponds Hatchery13 from March 2009 ndash March 201013 pond 7(top13 graph)13 and13 pond 8 (Lower13 graph)13 Temperatures recorded with a Hobotempregremote data logger every 3 hours

42

13

Results

Growth in Lined Ponds

Razorback suckers13 that had been13 in13 Pond 8 upper for the13 entire13 year13 grew an13

average of 0263 mmday (789 mmmonth) and razorback suckers that had been in the

pond for 7 months (Oct -shy‐ May) grew13 on13 average of 028 mmday (843 mmmonth) (Figure13

7) These growth13 rates13 did not significantly13 differ Fish density13 in Pond 3 during13 the13

majority of the growth period was13 00032 ndash 00036 fishgallon13 Additionally no13 significant

differences in growth rate were observed between fish smaller than 210 mm TL and fish

larger than 210 mm TL when all recaptured fish were combined

We also measured the growth rate of very large fish in a lined pond On Jan13 2513 201013

156 adult fish with PIT tags were recovered from13 Pond 3 upper13 These fish were13 in the13

pond for 257 days and experienced an average13 growth13 rate13 of 024mmday or 73

mmmonth (Figure13 7)13 This growth13 rate13 is slightly13 lower13 than13 the13 average13 growth13 rate13

observed13 at Bubbling13 Ponds Hatchery in other studies (0275 mmday 825 mmmonth)

but may not be biologically meaningful We would expect larger13 fish to13 have13 reduced

growth rates according to a typical Von Bertalanfy growth model (Bertalanffy 1957) but it

appears that13 over the size range we evaluated (300 -shy‐ 450 mm TL) growth rates have not

slowed significantly compared to that of smaller13 fish grown at Bubbling Ponds13 Hatchery

Growth13 of razorback suckers13 is known13 to13 slow as13 fish reach13 larger13 sizes but it appears13 this13

reduced growth rate may not really start to be biologically meaningful at Bubbling Ponds

Hatchery13 until razorback suckers13 exceed 450 mm TL

Growth in unlined ponds

Growth13 rates13 for the13 fish recaptured13 during13 the Pond 1 lower13 thinning13 (120 days13 in

the pond) was 024 plusmn 003 mmday (729 plusmn 090 mmmonth) (Figure13 8)13 Fish13 that were13 in

the pond for nearly the entire year grew13 an13 average13 of 024 plusmn 001 mmday (726 plusmn 027

mmmonth) These growth rates are surprisingly the lowest measured growth rates for

any part of our study and differ significantly from13 every other measured growth rate

except very large13 fish (Figure13 9)13 Separating13 out13 large fish that13 were in13 the pond for the

entire year makes no difference fish that were added to the pond at TL lt300 mm grew

43

13

Gro

wth

Rat

e (m

md

ay)

020

026

032

0244 plusmn 001 mmday (733 plusmn 028 mmmonth) and and those with TL gt= 300 mm at the

start of the experiment grew 022 plusmn 003 mmday (651 plusmn 101 mmmonth)

Razorback Growth Rates in Lined Ponds

Figure 7 Growth ofrazorback suckers in(mmday plusmn standard error)in Pond 8 upper in 2008-shy‐2009 An ANOVA did notdetect any significantdifferences

7 Months Full Year 300+ mm fish

Effects of sorting on growth

One hundred and seventy five tagged razorback suckers were recovered from13 Pond

8 upper13 on March13 24 2010 (378 days13 of growth)13 These were13 the13 larger sorted13 fish (gt140

mm TL) that came out of Pond13 5 on March13 11 2009 One13 hundred and13 twenty13 two13 tagged13

razorback suckers were also recovered from13 Pond13 7 upper on March13 31 2010 (385 days13 of

growth)13 These were13 the13 smaller sorted13 fish (lt140 mm TL) that came out of Pond13 5 on

March 1113 200913 No significant differences in growth rate (mmday) were observed among

larger fish in Pond 8 and smaller fish in Pond 7 (pgt005 ANOVA) (Figure 10)13 indicating

that13 sorting may have helped to offset the original slower growth trajectory of the smaller

fish Temperatures of Ponds 7 and 8 upper remained similar throughout the year13 (Figure

5)

44

13

13

13

Gro

wth

Rat

e (m

md

ay)

Gro

wth

Rat

e (m

md

ay)

020

026

032

020

026

032

Razorback Growth in an Unlined Pond

Figure 8 Growth of razorbacksuckers (mmday plusmn standard error) in Pond 1 lower (an unlined pond)in 2010-shy‐2011 An ANOVA did notdetect any significant differences

6 Months 12 Months lt 300 mm Fish 300+ mm Fish Growth Growth

Lined vs Earthen Ponds 1 year of growth

Figure 9 Growth of razorbacksuckers (mmday plusmn standard error) in lined and unlined ponds A t-shy‐test13 did not detect a significantdifference

Lined Pond Unlined Pond 1 Yr Growth 1 Yr Growth

45

13

Effect of Sorting G

row

th R

ate

(mm

day

) G

row

th R

ate

(mm

day

)

032

020

026

032

020

026

Smaller Fish Larger Fish

Effect of Ich

Figure 10 Average growthof razorback suckers(mmday plusmn standard error)that were size-shy‐sorted intosmall fish (pond 7) and largefish (pond 8) populations At-shy‐test did not detect asignificant difference

Figure 11 Average growth ofrazorback suckers (mmday plusmnstandard error) after Ich wasremovd from the hatcheryrsquos springand after Ich was again detected inthe pond The growth rate withoutIch is significantly higher than boththe rate after Ich and the ourstudyrsquos average annual growth ratein lined ponds (ANOVA p =00003)

Growth without Ich Growth With Ich Average Annual 4 months 4 months Growth Rate

46

13

Effect of Ich on razorback sucker growth rates

Seventy-shy‐four13 tagged13 razorback suckers13 were13 recovered from13 Pond 8 on September

15 2010 These fish had13 been13 in the pond for 4 months and experienced a growth rate of

032 mmday or 97 mmmonth (Figure13 11)13 This growth13 rate13 is significantly higher (p =

005 two sample t-shy‐test) than the mean growth rate for the same group13 of tagged fish after

Ich detection (022 mmday or 65 mmmonth) and significantly higher than any other

individual growth13 rates13 observed13 to13 date13 at Bubbling13 Ponds Hatchery13 (Figure13 11)13 If this13

growth13 rate13 were13 extended throughout13 the entire13 year13 fish on average from13 Ich-shy‐free13 ponds13

would be 16 mm longer than fish from13 ponds infested with Ich Studies conducted at

Bubbling Ponds hatchery in 2008 (Ward 2008) did not reveal any effects of the treatment

chemicals on razorback sucker growth rates so it13 is likely that13 the parasite outbreaks

themselves are causing reducing growth rates rather than the chemicals used to treat the

parasites13

Conclusions

Our results suggest that under typical hatchery operations (maximizing number of

fish produced)13 the growth13 rate13 of razorback13 suckers13 is relatively13 consistent at Bubbling13

Ponds hatchery13 at 02-shy‐03 mmday (6-shy‐9 mmmonth)13 but is lower than growth13 rates13 at

other13 facilities (02 ndash 18 mmday Ward et al 2007)13 This growth13 rate13 has13 been13 constant in

both lined and unlined ponds and at all fish densities we were able to measure To achieve13

growth13 rates13 substantially higher than this will likely require13 significant changes in rearing

practices that may not be practical in order to reach numerical production13 goals

Temperature is a key variable in fish growth but seasonal growth patterns

described13 above13 (Figure13 5) demonstrate that water temperatures are high enough in

winter to maintain razorback growth Differences in water temperature by season

currently13 do not fluctuate more than 10degC at Bubbling Ponds because of the continuous

supply of water flowing through each pond (approx 225 gallonsmin) These high water

flows appear to keep pond temperatures within the thermal preference13 for razorback

suckers13 (1213 -shy‐ 28 degC Bulkley and Pimentel 1983) throughout the entire year with

temperatures rarely dropping13 below 16deg13 C (Figures 513 6)13

47

13

Fish density is another key variable in fish growth and though the number of fish in

a pond during our study ranged from13 3000 to 700013 fish we13 did not find any13 correlation13

between13 density and growth rate13 This might yield two conclusions First13 razorback

growth13 may be changed equally13 by13 densities13 at the13 hatchery13 (ie13 a density13 of 3000 fish in a

pond is as stressful13 for razorbacks as a density13 of 7000 fish) An alternative is that other

factors13 such as disease outbreaks have13 stronger13 control over fish growth13 than13 density13

Fish density13 would13 have13 to13 be13 experimentally manipulated to test13 this13 and hatchery

operations (producing the maximum13 number of fish) prevented our manipulating density13

in ponds for this13 work The trouble with manipulating density demonstrates the difficulties

associated with changing13 hatchery13 practices experimenting with density would have

prevented BPH from13 meeting13 production13 goals Given that the stocking of smaller

razorbacks has met with very little success perhaps BPH goals could be changed from13

producing 12000 fish at 300+ mm per year to a smaller number of very large fish each

year Growing13 fewer13 larger13 fish could potentially be accomplished in the same time frame

as more smaller fish but a better understanding of how density alters growth rate would

be required to be confident13 of this

The very slow growth13 in the13 earthen13 unlined13 Pond 1 lower13 was very surprising We13

had13 anticipated13 that the13 diversified diet13 cover and13 other13 habitat features13 provided by13

unlined ponds would yield dramatically increased growth rates However these traits were

not enough to offset high fish densities and in fact the unlined pond in our study13 suffered

mortality to bring densities down to that observed normally in lined ponds

Our data13 suggest13 that razorbacks13 sucker13 growth13 rates13 are13 higher in lined13 ponds13

However we13 think the reasons13 for the13 very slow growth we observed13 in the13 unlined13 pond13

in our study13 is instead13 linked13 to13 the13 usage13 of Pond 1 lower13 during13 the13 study13 rather13 than13

intrinsic13 slow growth13 in earthen13 ponds First the pond was at extremely high density for at

least part of the study The volume of Pond 1 lower has not been estimated but hatchery

managers suggest 1500-shy‐2000 fish is an appropriate number of individuals so this pond

was at a very high density for much of the experiment Second dissolved oxygen is often

very low in the13 large13 earthen13 ponds during the heat of summer much lower than that of

lined ponds This will both limit the number of fish that can survive in the pond and almost

certainly13 increases stress13 of these13 fish potentially13 reducing growth13 The DO crashes also13

48

13

limit the amount of feed hatchery managers can give fish in these ponds sometimes for

days or weeks at a time which further reduces growth during warm13 weather

Our data13 suggests that13 growth rates at the Bubbling13 Ponds Fish Hatchery are likely

as high as possible given13 the pond densities required to meet production goals and the Ich-shy‐

infested water that feeds the facility Sorting practices are successful in helping as many

fish as possible reach stocking length as fast as possible Unlined ponds may be able to

grow13 large13 fish at low13 densities13 but whatever factors allow13 for that13 growth are not13 able to

overcome high fish density The removal of invasive13 fis that act as13 a host for the13 parasite13

Ich fish from13 the Bubbling13 Ponds spring13 allowed the highest13 growth rate at 032 mmday13

(96 mmmonth) but that growth rate decreased again as Ich re-shy‐infested13 the13 hatchery13

Consistently13 achieving13 growth13 rates13 as high or substantially13 higher than13 this13 will likely13

require13 significant changes in rearing practices that may not be practical in order to13 reach13

numerical production13 goals

Two major changes that might result in higher growth rates are substantially

reducing fish density and modifying the way spring water is delivered to the facility (via

either repeated chemical treatments or enclosed concrete water diversions) to eliminate

Ich from13 the hatchery source water Other potential changes not address by our work

include13 flow-shy‐training razorbacks much previous literature including MSCP-shy‐funded13 work

on razorback suckers13 suggests13 that fish growing13 in flowing water will grow13 faster than fish

in still water (Jorgensen and Jobling 1994) Furthermore there are a wide variety of

potential benefits associated with growing13 fish13 in flowing13 water in addition13 to increased

growth13 rates13 (Davidson13 199713 Castro13 et al13 2011) Another option13 for increasing13 growth13

rates13 include13 changing to13 intensive13 culture13 in large circular13 tanks

Finally given that the stocking of smaller razorbacks has met with very little

success13 perhaps13 BPH13 goals13 could13 be13 changed from13 producing 12000 fish at 300+ mm per

year to a smaller number of very large fish each year Growing fewer larger fish could

potentially be accomplished in the same time frame as more smaller fish but a better

understanding13 of how density13 alters growth13 rate13 would13 be13 required to13 be13 confident of this

49

13

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower13 Colorado13 River Multi-shy‐Species13

Conservation Program13 (LCRMSCP) under Work Task C10 We13 thank Ty Wolters13 Tom13

Burke13 and Eric13 Volkman for their support of this research and Frank Agygos and Dave

Billingsly13 of the Bubbling13 Ponds Fish Hatchery13 for their willingness to participate in13 this

research13 and13 for their technical assistance We also thank the LCRMSCP fish group from13

Boulder City13 NV for their assistance with harvesting13 ponds and tagging13 fish13

50

13

Literature13 CitedAnders P J 1998 Conservation aquaculture and endangered species can objective science13

prevail13 over risk13 anxiety Fisheries 23(11) 28-shy‐31

Anderson R O and R M Nuemann 1996 Length weight and associated structural indicesPages 447 ndash 482 in B R Murphy13 and D13 W Willis13 editors13 Fisheries techniques13 2ndedtion American Fisheries13 Society13 Bethesda13 Maryland

Bain M B J T Finn and H E Brooks 1988 Streamflow regulation and fish communitystructure13 Ecology13 69382-shy‐392

Bays J H Zarbock R Whitman and T Murphy 2005 Conceptual design and managementof native13 fish refugia on the13 lower13 Colorado13 River In13 CL Spring13 and13 S Leoneditors Proceedings of two symposia Restoring native fish to the lower ColoradoRiver13 interactions13 of native and non-shy‐native13 fishes 13ndash1413 July13 1999 Las13 Vegas13 Nevada13 Restoring13 natural function within a modified riverine environment thelower Colorado River13 8ndash913 July13 1998 U S Fish and13 Wildlife13 Service Southwestern13 Region Albuquerque New Mexico Pages 167-shy‐177

Bertalanffy L Von 1957 Quantitative laws in metabolism13 and growth13 Q Rev Biology 32217 ndash 231

Bingham T B Scheer and C McAda 2003 Propagation facilities in Grand Valley (24 RoadHatchery Horsethief13 Ponds and13 grow-shy‐out ponds) for captive13 rearing13 ofendangered13 fishes for the13 upper13 Colorado13 River basin13 Colorado River RecoveryProgram FY2003 annual project report13 US Fish and13 Wildlife13 Service GrandJunction13 4pp

Birchell G J and K Christopherson 2004 Survival growth and recruitment of larval andjuvenile razorback13 sucker (Xyrauchen texanus) introduced13 into13 floodplain13 depressions13 of the13 Green River Utah13 Final report13 Upper13 Colorado13 RiverEndangered Fish Recovery Program13 Project No C-shy‐6RZ Publication Number 04-shy‐1513 Utah13 Division of Wildlife13 Resources Salt Lake13 City13 Utah13 67 pages

Brannon E L 1993 The perpetual oversight of hatchery programs Fishery Research 1819-shy‐27

Brett J R 1979 Environmental Factors and growth pages 599-shy‐67513 InW S Hoar13 D13 J13 Randall and J R Brett (eds) Fish Physiology Volume 8 Bioenergetics and GrowthAcademic Press New York

Brooks J E 1986 Annual reintroduction and monitoring report for razorback suckerXyrauchen texanus in the Gila River Basin Arizona 1985 US Fish and WildlifeService13 Offices of Endangered13 Species and Fishery13 Resources Albuquerque 23 pp

51

13

Brunson13 R E and K D13 Christopherson13 200513 Larval13 razorback13 sucker and bonytailsurvival and13 growth13 in the13 presence13 of nonnative13 fish in the13 Baeser13 floodplainwetland of the middle Green River Final report prepared for Upper13 Colorado RiverBasin Endangered Fish Recovery Program Project No C-shy‐6-shy‐rz-shy‐bt Publication13 No 05-shy‐26 Utah13 Division of Wildlife13 Resources13 Vernal13 32 pp

Bulkley R V and R Pimentel 1983 Temperature preference and avoidance by adultrazorback suckers Transactions of the American Fisheries Society 112601-shy‐607

Burke13 T13 199513 Rearing13 wild razorback13 sucker larvae in13 lake-shy‐side13 backwaters13 LakeMohave ArizonaNevada Proceedings of the Desert Fishes Council 2635

Busacker G P I R Adelman and E M Goolish13 199013 Growth13 Pages 363 ndash 387 in C BSchreck and p B Moyle editors Methods for fish biology American FisheriesSociety Bethesda Maryland

Castro V B Grisdale-shy‐Helland S J Helland T Kristensen S M Jorgensen J Helgrud13 GClaireaux A P Farrell A Krasnov and H Takle 2011 Aerobic training stimulatesgrowth and promotes disease resistance in Atlantic salmon (Salmo salar)Comparative Biochemistry and Physiology -shy‐ Part A Molecular amp IntegrativePhysiology13 160(2) 278-shy‐290

Czapla T E 2002 Facilities plan for the production of endangered fishes to meet statestocking13 plans13 as13 part of the13 Upper13 Colorado13 River Endangered13 Fish RecoveryProgram Upper Colorado River Basin Recovery Implementation Program US Fishand Wildlife Service13 Denver13 9 pp

Davidson W 1997 The effects13 of exercise13 training on teleost fish a review of recentliterature Comput Biochem Physiol 117A67ndash75

Figiel Jr C R 2005 Annual report fiscal year 2004 Willow Beach National13 Fish HatcheryUS Fish and Wildlife13 Service Willow Beach 17 pp

Figiel Jr C R M E Ulibarri G Carmichael J Seals and J N Hanson 2005 Intensive13 fish13 culture of warmwater native fishes at a coldwater fish hatchery Pages 164-shy‐16613 inProceedings of two symposia restoring native fish to the lower Colorado13 River13 interaction13 of native13 and13 non-shy‐native13 fishes July13 13-shy‐1413 1999 Las Vegas Nevada USFish and Wildlife Service Southwest Region Albuquerque New Mexico

Gerking13 S D 1978 Ecology of freshwater fish13 production13 Halstead Press13 New13 York

Gustafson W and Q Bradwisch 2000 Wahweap operation and maintenance -shy‐-shy‐ UtahColorado River Recovery Program FY 2000 annual project report Project No 29cUtah13 Division of Wildlife13 Resources Page AZ 3pp

52

13

Hamman R L 1985 Induced spawning of hatchery-shy‐reared13 razorback sucker ProgressivFish Culturist 47(3) 187-shy‐189

Hanson J N 1996 Annual report fiscal year 1996 Willow Beach National Fish HatcheryUS Fish and Wildlife Service13 Willow Beach 9pp

Irving D S Seversen and M Montagne 2004 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2004 annual project13 report Report No 29b US Fish and13 Wildlife13 Service Vernal 3pp

Jorgensen E H and13 M Jobling 1994 Feeding and13 growth13 of exercised13 and13 unexercised13 juvenile Atlantic salmon in freshwater and performance after transfer to seawaterAquaculture International 2 154-shy‐164

Kaeding L R and D B Osmundson 198913 Colorado13 Squawfish13 and13 razorback sucker grow-shy‐out pond studies as part of conservation measures for the green mountain andRuedi reservoir water sales Final report for agreement number 6-shy‐AA-shy‐60-shy‐00150

Koebele13 B P13 198513 Growth and the size hierarchy effect an experimental assessment ofthree proposed mechanisms activity differences disproportional food acquisition13 pysiological stress Environmental Biology of Fishes 12 181-shy‐188

Kretschmann A E and L L Leslie 2006 Razorback sucker (Xyrauchen texanus) status13 reproduction and recruitment in Senator Wash Reservoir CA Final Report13 to USBurea of Reclamation Cooperative Agreement No 00-shy‐FG-shy‐34-shy‐ 0009 p 32 ArizonaGame and Fish Department Phoenix

Marsh13 P13 C13 1987a13 Digestive tract13 contents13 of adult razorback suckers13 in Lake13 MohaveArizona-shy‐Nevada Transactions of the American Fisheries Society 116117-shy‐119

Marsh P C 1987b Native fishes at Buenos Aires National Wildlife Refuge and ArizonaState University Research Park Arizona opportunities for management researchand public13 education13 on13 endangered species13 Proceedings of the Desert13 FishesCouncil 1967-shy‐78

Marsh P C 1994 Rearing native Colorado River fishes in golf course ponds Arizona StateUniversity Tempe 22 + pages

Marsh13 P13 C13 200013 Fish population13 status and evaluation13 in13 the Cibola13 High Levee PondFinal report agreement number 99-shy‐FG-shy‐30-shy‐00051 US Bureau of ReclamationBoulder City13 Nevada13 20 pages

Marsh P C and C A Pacey 1998 Growth of wild adult razorback suckers13 in Lake13 Mohave13 Arizona-shy‐Nevada13 Final report13 US Bureau of Reclamation Boulder City Nevada 25pages + appendices

53

13

Marsh P C B R Kesner and C A Pacey 2005 Repatriation as s management strategy13 to13 conserve a critically13 imperiled fish species North American Journal of FisheriesManagement 25 547-shy‐556

Marsh P C and C A Pacey 2005 Immiscibility of native and non-shy‐native13 fishes Pages 59-shy‐63 inMJ13 Brouder13 CL13 Springer13 and CS13 Leon13 editors13 Proceedings of two13 symposia Restoring native fish to the lower Colorado River interactions of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 NV and13 Restoring natural13 function within a modified riverine environment the lower Colorado River13 July13 8-shy‐913 1998 Las Vegas NV US Fish and13 Wildlife13 Service Southwest Region AlbuquerqueNew Mexico

Marsh13 P13 C13 and J13 E Brooks13 198913 Predation13 by ictalurid catfishes as a deterrent13 toreestablishment of hatchery-shy‐reared13 razorback sucker The Southwestern Naturalist34188-shy‐195

Matthews R A 2005 Ichthyopthirus multifiliis Fouquet and Ichthyopthirosis infreshwater13 teleosts13 Pages13 159-shy‐218 in Advances in Parasitology volume 59 J RBaker R Muller D Rollinson (eds) Academic Press

McCarthy13 M S and W L Minckley 1987 Age estimation for razorback sucker (PiscesCatostomidae) from13 Lake Mohave Arizona and Nevada Journal of the Arizona-shy‐Nevada Academy of Science 2187-shy‐97

Minckley13 W L13 198313 Status of the razorback13 sucker13 Xyrauchen texanus (Abbot)13 in13 thelower Colorado River basin13 The Southwestern13 Naturalist13 28(2) 165-shy‐187

Minckley13 W L13 199113 Native fished of the Grand Canyon13 region an obituary13 Pages 124-shy‐177 in Colorado River ecology and dam13 management National Academy PressWashington13 DC

Minckley13 C13 O and M LaBarbara13 199913 Report13 on13 native fish grow-shy‐out facilities13 at Cibolaand Imperial National Wildlife Refuges 1993-shy‐199513 US Fish and13 Wildlife Service13 Parker Fishery Resources Office Parker Arizona

Modde13 T13 199613 Juvenile razorback sucker (Xyrauchen texanus) in a managed wetlandadjacent13 to the Green13 River13 Great13 Basin13 Naturalist13 56375-shy‐376

Modde T KP Burnham and E J Wick 1996 Population status of the razorback sucker13 inthe middle Green River (USA) Conservation13 biology 10 110-shy‐119

Modde13 T13 and G13 B Haines13 200513 Survival13 and growth of stocked razorback13 sucker andbonytail in multiple floodplain wetlands of the middle Green River under resetconditions13 Final report prepared for Upper Colorado13 River13 Basin RecoveryImplimentation Program US Fish and Wildlife Service Vernal 66 pp

54

13

Modde T Z H Bowen and D C Kitcheyan 2005 Spatial and temporal use of a spawning13 site in the middle Green River by wild hatchery-shy‐reared13 razorback suckers13 Transactions of the American Fisheries Society 134937-shy‐944

Mueller13 G13 199213 The native fish work13 group13 -shy‐ a multiagency endeavor to improve thestatus of the razorback sucker in Lake Mohave AZ-shy‐NV13 Proceedings of the DesertFishes Council 2369

Mueller G 1995 A program13 for maintaining the razorback sucker in Lake MohaveAmerican Fisheries Society Symposium 15127-shy‐135

Mueller13 G13 200613 Ecology of the bonytail13 and razorback13 sucker and the role of offchannelhabitats13 in their13 recovery Scientific13 investigations13 report 2006-shy‐5065 US GeologicalSurvey13 Denver

Mueller G and E Wick 1998 Testing of golf course ponds at Page Arizona for suitability13 as grow-shy‐out facility for razorback sucker using surplus fish from13 Ouray NationalFish Hatchery National Park Service US Fish and13 Wildlife13 Service and UtahDivision of Wildlife13 Resources 28 pages

Mueller13 G13 and T13 Burke13 200513 Survival13 of young13 razorback13 sucker (Xyrauchen texanus) inrelation to13 stocking rates13 (fishha)13 and13 in the presence13 or absence13 of predatorcommunities in Lake Mohave Arizona-shy‐Nevada13 Pages13 155-shy‐16313 in Proceedings of two13 symposia restoring native fish to the lower Colorado River interaction13 of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 Nevada US Fish and Wildlife13 Service Southwest Region Albuquerque New Mexico

Mueller13 G13 J13 Carpenter13 and P13 C13 Marsh13 200413 Cibola13 High Levee Pond annual report 2004US Geological Survey Fort Collins13 Science Center13 Colorado13 and Arizona StateUniversity Tempe 23 pages

Nesler T P K Christopherson J M Hudson C W McAda F Pfeifer and T E Czapla 2003An integrated stocking plan for razorback sucker bonytail and Colorado13 pikeminnow for the Upper Colorado River Endangered Fish Recovery ProgramAddendum13 to State Stocking Plans Upper Colorado River Basin Recovery13 Implementation Program 12 pp

Papoulias13 D and W13 L Minckley13 1992 Effects13 of foo availability13 on survival and growth13 of larval razorback suckers13 in ponds Transactions of the American Fisheries Society121340-shy‐355

Paukert13 C P D L Ward13 P J Sponholtz13 and K13 D Hilwig13 Effects13 of repeated hoopnetting13 on bonytail chub13 Journal of Freshwater13 Ecology13 20(4) 649-shy‐653

Pfeifer F M13 C Baker13 and M13 Montagne13 199913 Propagation13 facilities13 in the13 Grand Valley13 (24 Road13 Hatchery13 Horsethief13 Ponds and13 grow-shy‐out ponds) for captive rearing of

55

13

endangered13 fishes for the13 Upper Colorado13 River Basin13 Colorado13 River Recovery13 Program FY 99 annual project report Project No 29a13 US Fish and Wildlife Service13 Grand13 Junction13 5pp

Pfeifer F S Seversen and M Montagne 2003 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2003 annual reportProject No 29b13 US Fish and Wildlife13 Service Vernal13 4pp

Rabago-shy‐Castro J L Sanchez13 J G Perez-shy‐Castaneda R and13 Gonzalez-shy‐Gonzlez A 2006Effects of the prophylactic use of Romet-shy‐3013 and13 copper13 sulfate13 on growth13 condition13 and feeding13 indicies in13 channel13 catfish (Ictalurus punctatus) Aquaculture 253 343-shy‐349

Reinitz GL L E Orme and F N Hitzel 1979 Variations of body compositio and growth13 among strains of rainbow trout Transactions of the American Fisheries Society 108204-shy‐207

Ruppert13 J13 B P B Holden13 and P D Abate 1999 Age estimation and growth of razorbacksucker13 Xyrauchen texanus in Lake13 Mead Nevada Proceedings13 of the Desert FishesCouncil 3040

Schnoor K D and J Logan 2002 Operation and maintenance of JW Mumma nativeaquatic13 species restoration facility Colorado Colorado River Recovery Program FY2002 annual project report13 Project No 29d Colorado13 Division of Wildlife Alamosa3pp

Salisbury13 L13 1998 Factors13 affecting razorback13 sucker growth13 in Lake13 Mohave backwaters13 MS Thesis13 Unviersity13 of Nevada13 Las13 Vegas

Schooley J13 D13 and P C13 Marsh13 2007 Stocking of endangerdd13 razorback13 suckers13 in thelower Colorado River Basin13 over three decades 1974-shy‐2004 North American Journalof Fisheries Management 27 43-shy‐51

Severson S H H M Tyus and G B Haines 1992 An evaluation of feeds for raisingrazorback sucker Xyrauchen texanus Journal of Applied Aquaculture 155-shy‐65

Toney D P 1974 Observations13 on the13 propagation13 and13 rearing13 of two13 endangered species13 in a hatchery environment Proceedings of the Annual Conference of the Western13 Association of State Game and Fish Commissions 54 252-shy‐259

Tyus H M13 1998 Razorback sucker13 (Xyrauchen texanus) recovery plan13 University13 ofColorado Center for Limnology Boulder13 76 pages

Tyus H M13 and13 S H Severson 1990 Growth13 and13 survival of larval razorback suckers fedfive formulated diets The Progressive Fish Culturist 52197-shy‐200

56

13

Ulibarri M E 2003 Annual report fiscal year 2001 Dexter National Fish Hatchery13 andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 26 pages

Ulibarri M E 2003 Annual report fiscal year 2002 Dexter National Fish Hatchery andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 59 pages

USBR 2006 Lower13 Colorado13 River Multi-shy‐Species Conservation Program final fishaugmentation plan Boulder City 19 pp

USFWS 2002 Razorback sucker (Xyraouchen texanus) recovery goals Amendment andsupplement to the Razorback Sucker Recovery Plan13 US Fish and Wildlife Service13 Region 6 Denver13 Colorado

USFWS 1999 Annual report 1999 Ouray National Fish Hatchery Vernal 25pp

USFWS 2004 Management plan for the big-shy‐river13 fishes of the13 lower13 Colorado13 river basinamendment and supplement to the bonytail humpback chub Coloradopikeminnow and razorback sucker recovery plans

USFWS13 2005 Station13 profile13 of the13 Dexter13 National Fish Hatchery13 and Technology CenterUS Fish and Wildlife13 Service Dexter

Valdez R A P G Mangan R Smith and B Nilson 1982 Upper Colorado River fisheriesinvestigations13 inW H Miller J J Valentine D L Archer H M Tyus R A Valdezand L13 Kaeding13 editors13 Colorado River Fishery13 Project13 Part 2 Field13 investigations13 US Bureau of Reclamation Salt Lake City Utah

WBNFH 2004 Culture methods of the endangered razorback sucker Xyrauchen texanusUS Fish and Wildlife13 Service Willow Beach National Fish Hatchery13 8 pp

Ward D 2008 Effects of disease treatments on growth of razorback sucker ReportSubmitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 Inpartial fulfillment of work task C10 agreement number 06FG30039

Ward13 D13 M Childs and W Persons 2007 Factors13 affecting13 growth13 of razorback sucker13 (Xyrauchen texanus) in captivity Literature review and knowledge assessmentReport Submitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 In partial fulfillment of work task C10 agreement number 06FG30039

57

Appendices

Appendix 1 Survey Questions Survey of Razorback Sucker Culture in the

Southwestern United States

The enclosed survey is being distributed by the Arizona Game and Fish Department to razorback sucker culture facilities throughout

the Southwestern United States The purpose of this survey is to consolidate information regarding culture of this species so that

appropriate facility improvements can be considered for Bubbling Ponds Hatchery in Arizona Specifically we wish to increase

growth rate and production efficiency at the hatchery Information gathered in this survey will be summarized in a final report to US

Bureau of Reclamation in Boulder City NV and disseminated to all facilities that participate in the survey A workshop to discuss

the findings of this study as well as to share general information concerning razorback sucker culture will be organized by the

Arizona Game and Fish Department at the conclusion of this study and all participants will be invited

Thank you for taking the time to fill out this survey Please contact Mike Childs if you have questions or would like to discuss the

survey

Mike Childs

mchildssedonanet

(928) 639-1346

(928) 634-1279

Facility_____________________________________ Date___________________

Contact Phone _____________________________

ContactPerson_______________________________

Contact Email _______________________________

1 Water quality ranges at this culture facility

Season

Spring (Mar-May) Summer (Jun-Aug) Fall (Sept-Nov) Winter (Dec-Feb)

Temperature (C)

PH

DO (mgL)

PO4 (mgL)

TDS (mgL)

Hardness (mgL)

CaCO3

Pathogens

37

13

Growth rate13 in an unlined pond

To document razorback sucker growth in earthen ponds we introduced13 225 tagged13

razorback suckers13 into13 Pond13 1 lower13 (Figure 4) in February 3 2010 Additional tagged fish

from13 other studies were added to the pond throughout the growing season and the density

of 1 lower reached a maximum13 of nearly 7000 fish in early summer 2010 Density was

reduced to approximately 6000 fish by capturing fish with hoop nets on June 3 2010 54 of

these fish were tagged fish and returned to 1 lower after being weighed and measured The

pond was harvested on January13 2713 2011 and a total13 of 254 tagged fish out13 of 4296 fish

total were removed from13 the pond The pond was harvested on January 27 2011 (358 days13

of growth) and the tagged fish were weighed and measured Total number of razorbacks in

the pond at harvest13 was 4296

Effect of sorting practices on growth rates

On March 1113 200913 Pond13 5 upper was13 harvested13 and13 split into13 two13 separate13 groups

Two hundred of the smaller fish (average size = 122 mm TL) were PIT tagged and placed

into13 Pond13 7 upper and13 200 of the13 larger13 fish (average = 160 mm TL) were PIT tagged and

placed int Pond13 8 upper Density13 in Pond13 7 was13 4500 fish and13 in Pond13 8 there13 were13 6500

fish These ponds were then harvested after 1 year and growth rates were compared to

give information on the effects of current sorting practices Hobotempreg temperature

loggers were installed in13 Ponds 7 and13 8 during13 the13 grow-shy‐out period with13 water13

temperature recorded every 2 hours13 (Figure13 6)

Effect of Ich on razorback sucker growth rates

Bubbling Ponds spring was treated with Rotenone (CFT Legumine 5) at a

concentration of 2 ppm13 to remove all mosquitofish from13 the spring The treatment

consisted of two treatments 6 hours in duration on two consecutive days (April 12 -shy‐ 13)

using13 drip13 stations13 and13 backpack sprayers13 followed13 by13 an13 additional 6 hours13 of

detoxification using sodium13 permanganate Although 12 mosquitofish were captured in the

spring pond the week following the treatments subsequent minnow trapping (20 traps

checked13 daily13 for 3 weeks) did not capture any additional fish until August 11 2010 when

41

13

juvenile mosquitofish were again detected in the spring pond Minnow traps have

subsequently been set daily with several hundred individuals removed To evaluate if Ich

was also again present in the spring we captured 15 mosquitofish from13 the spring pond on

three separate days and placed them13 in an aquaria at 25 degC with 5 longfin dace known to be

free of Ich These fish were monitored for 2 weeks with no signs of Ich developing This

indicates that even though mosquitofish have returned to the spring pond the parasite is no

longer present13 although how13 long13 this condition13 will13 persist13 is unknown13

On May 1113 201013 200 juvenile razorback13 suckers were harvested out13 of Pond 5

upper (2009 year Class from13 Dexter National Fish Hatchery) and were PIT tagged and

placed into Pond 8 to evaluate if growth rates at bubbling ponds hatchery have improved

following the renovation of the spring and the removal of the Ich parasite Unfortunately13

on Sept13 8 2010 Ich was13 again13 detected13 in Pond 8 and the pond was immediately seined

and 74 tagged fish were measured to obtain growth information for the 4-shy‐month period

during13 which13 the13 pond13 was13 Ich-shy‐free13

Figure13 6 Temperatures (degC) in rearingponds 7 and 8 at Bubbling Ponds Hatchery13 from March 2009 ndash March 201013 pond 7(top13 graph)13 and13 pond 8 (Lower13 graph)13 Temperatures recorded with a Hobotempregremote data logger every 3 hours

42

13

Results

Growth in Lined Ponds

Razorback suckers13 that had been13 in13 Pond 8 upper for the13 entire13 year13 grew an13

average of 0263 mmday (789 mmmonth) and razorback suckers that had been in the

pond for 7 months (Oct -shy‐ May) grew13 on13 average of 028 mmday (843 mmmonth) (Figure13

7) These growth13 rates13 did not significantly13 differ Fish density13 in Pond 3 during13 the13

majority of the growth period was13 00032 ndash 00036 fishgallon13 Additionally no13 significant

differences in growth rate were observed between fish smaller than 210 mm TL and fish

larger than 210 mm TL when all recaptured fish were combined

We also measured the growth rate of very large fish in a lined pond On Jan13 2513 201013

156 adult fish with PIT tags were recovered from13 Pond 3 upper13 These fish were13 in the13

pond for 257 days and experienced an average13 growth13 rate13 of 024mmday or 73

mmmonth (Figure13 7)13 This growth13 rate13 is slightly13 lower13 than13 the13 average13 growth13 rate13

observed13 at Bubbling13 Ponds Hatchery in other studies (0275 mmday 825 mmmonth)

but may not be biologically meaningful We would expect larger13 fish to13 have13 reduced

growth rates according to a typical Von Bertalanfy growth model (Bertalanffy 1957) but it

appears that13 over the size range we evaluated (300 -shy‐ 450 mm TL) growth rates have not

slowed significantly compared to that of smaller13 fish grown at Bubbling Ponds13 Hatchery

Growth13 of razorback suckers13 is known13 to13 slow as13 fish reach13 larger13 sizes but it appears13 this13

reduced growth rate may not really start to be biologically meaningful at Bubbling Ponds

Hatchery13 until razorback suckers13 exceed 450 mm TL

Growth in unlined ponds

Growth13 rates13 for the13 fish recaptured13 during13 the Pond 1 lower13 thinning13 (120 days13 in

the pond) was 024 plusmn 003 mmday (729 plusmn 090 mmmonth) (Figure13 8)13 Fish13 that were13 in

the pond for nearly the entire year grew13 an13 average13 of 024 plusmn 001 mmday (726 plusmn 027

mmmonth) These growth rates are surprisingly the lowest measured growth rates for

any part of our study and differ significantly from13 every other measured growth rate

except very large13 fish (Figure13 9)13 Separating13 out13 large fish that13 were in13 the pond for the

entire year makes no difference fish that were added to the pond at TL lt300 mm grew

43

13

Gro

wth

Rat

e (m

md

ay)

020

026

032

0244 plusmn 001 mmday (733 plusmn 028 mmmonth) and and those with TL gt= 300 mm at the

start of the experiment grew 022 plusmn 003 mmday (651 plusmn 101 mmmonth)

Razorback Growth Rates in Lined Ponds

Figure 7 Growth ofrazorback suckers in(mmday plusmn standard error)in Pond 8 upper in 2008-shy‐2009 An ANOVA did notdetect any significantdifferences

7 Months Full Year 300+ mm fish

Effects of sorting on growth

One hundred and seventy five tagged razorback suckers were recovered from13 Pond

8 upper13 on March13 24 2010 (378 days13 of growth)13 These were13 the13 larger sorted13 fish (gt140

mm TL) that came out of Pond13 5 on March13 11 2009 One13 hundred and13 twenty13 two13 tagged13

razorback suckers were also recovered from13 Pond13 7 upper on March13 31 2010 (385 days13 of

growth)13 These were13 the13 smaller sorted13 fish (lt140 mm TL) that came out of Pond13 5 on

March 1113 200913 No significant differences in growth rate (mmday) were observed among

larger fish in Pond 8 and smaller fish in Pond 7 (pgt005 ANOVA) (Figure 10)13 indicating

that13 sorting may have helped to offset the original slower growth trajectory of the smaller

fish Temperatures of Ponds 7 and 8 upper remained similar throughout the year13 (Figure

5)

44

13

13

13

Gro

wth

Rat

e (m

md

ay)

Gro

wth

Rat

e (m

md

ay)

020

026

032

020

026

032

Razorback Growth in an Unlined Pond

Figure 8 Growth of razorbacksuckers (mmday plusmn standard error) in Pond 1 lower (an unlined pond)in 2010-shy‐2011 An ANOVA did notdetect any significant differences

6 Months 12 Months lt 300 mm Fish 300+ mm Fish Growth Growth

Lined vs Earthen Ponds 1 year of growth

Figure 9 Growth of razorbacksuckers (mmday plusmn standard error) in lined and unlined ponds A t-shy‐test13 did not detect a significantdifference

Lined Pond Unlined Pond 1 Yr Growth 1 Yr Growth

45

13

Effect of Sorting G

row

th R

ate

(mm

day

) G

row

th R

ate

(mm

day

)

032

020

026

032

020

026

Smaller Fish Larger Fish

Effect of Ich

Figure 10 Average growthof razorback suckers(mmday plusmn standard error)that were size-shy‐sorted intosmall fish (pond 7) and largefish (pond 8) populations At-shy‐test did not detect asignificant difference

Figure 11 Average growth ofrazorback suckers (mmday plusmnstandard error) after Ich wasremovd from the hatcheryrsquos springand after Ich was again detected inthe pond The growth rate withoutIch is significantly higher than boththe rate after Ich and the ourstudyrsquos average annual growth ratein lined ponds (ANOVA p =00003)

Growth without Ich Growth With Ich Average Annual 4 months 4 months Growth Rate

46

13

Effect of Ich on razorback sucker growth rates

Seventy-shy‐four13 tagged13 razorback suckers13 were13 recovered from13 Pond 8 on September

15 2010 These fish had13 been13 in the pond for 4 months and experienced a growth rate of

032 mmday or 97 mmmonth (Figure13 11)13 This growth13 rate13 is significantly higher (p =

005 two sample t-shy‐test) than the mean growth rate for the same group13 of tagged fish after

Ich detection (022 mmday or 65 mmmonth) and significantly higher than any other

individual growth13 rates13 observed13 to13 date13 at Bubbling13 Ponds Hatchery13 (Figure13 11)13 If this13

growth13 rate13 were13 extended throughout13 the entire13 year13 fish on average from13 Ich-shy‐free13 ponds13

would be 16 mm longer than fish from13 ponds infested with Ich Studies conducted at

Bubbling Ponds hatchery in 2008 (Ward 2008) did not reveal any effects of the treatment

chemicals on razorback sucker growth rates so it13 is likely that13 the parasite outbreaks

themselves are causing reducing growth rates rather than the chemicals used to treat the

parasites13

Conclusions

Our results suggest that under typical hatchery operations (maximizing number of

fish produced)13 the growth13 rate13 of razorback13 suckers13 is relatively13 consistent at Bubbling13

Ponds hatchery13 at 02-shy‐03 mmday (6-shy‐9 mmmonth)13 but is lower than growth13 rates13 at

other13 facilities (02 ndash 18 mmday Ward et al 2007)13 This growth13 rate13 has13 been13 constant in

both lined and unlined ponds and at all fish densities we were able to measure To achieve13

growth13 rates13 substantially higher than this will likely require13 significant changes in rearing

practices that may not be practical in order to reach numerical production13 goals

Temperature is a key variable in fish growth but seasonal growth patterns

described13 above13 (Figure13 5) demonstrate that water temperatures are high enough in

winter to maintain razorback growth Differences in water temperature by season

currently13 do not fluctuate more than 10degC at Bubbling Ponds because of the continuous

supply of water flowing through each pond (approx 225 gallonsmin) These high water

flows appear to keep pond temperatures within the thermal preference13 for razorback

suckers13 (1213 -shy‐ 28 degC Bulkley and Pimentel 1983) throughout the entire year with

temperatures rarely dropping13 below 16deg13 C (Figures 513 6)13

47

13

Fish density is another key variable in fish growth and though the number of fish in

a pond during our study ranged from13 3000 to 700013 fish we13 did not find any13 correlation13

between13 density and growth rate13 This might yield two conclusions First13 razorback

growth13 may be changed equally13 by13 densities13 at the13 hatchery13 (ie13 a density13 of 3000 fish in a

pond is as stressful13 for razorbacks as a density13 of 7000 fish) An alternative is that other

factors13 such as disease outbreaks have13 stronger13 control over fish growth13 than13 density13

Fish density13 would13 have13 to13 be13 experimentally manipulated to test13 this13 and hatchery

operations (producing the maximum13 number of fish) prevented our manipulating density13

in ponds for this13 work The trouble with manipulating density demonstrates the difficulties

associated with changing13 hatchery13 practices experimenting with density would have

prevented BPH from13 meeting13 production13 goals Given that the stocking of smaller

razorbacks has met with very little success perhaps BPH goals could be changed from13

producing 12000 fish at 300+ mm per year to a smaller number of very large fish each

year Growing13 fewer13 larger13 fish could potentially be accomplished in the same time frame

as more smaller fish but a better understanding of how density alters growth rate would

be required to be confident13 of this

The very slow growth13 in the13 earthen13 unlined13 Pond 1 lower13 was very surprising We13

had13 anticipated13 that the13 diversified diet13 cover and13 other13 habitat features13 provided by13

unlined ponds would yield dramatically increased growth rates However these traits were

not enough to offset high fish densities and in fact the unlined pond in our study13 suffered

mortality to bring densities down to that observed normally in lined ponds

Our data13 suggest13 that razorbacks13 sucker13 growth13 rates13 are13 higher in lined13 ponds13

However we13 think the reasons13 for the13 very slow growth we observed13 in the13 unlined13 pond13

in our study13 is instead13 linked13 to13 the13 usage13 of Pond 1 lower13 during13 the13 study13 rather13 than13

intrinsic13 slow growth13 in earthen13 ponds First the pond was at extremely high density for at

least part of the study The volume of Pond 1 lower has not been estimated but hatchery

managers suggest 1500-shy‐2000 fish is an appropriate number of individuals so this pond

was at a very high density for much of the experiment Second dissolved oxygen is often

very low in the13 large13 earthen13 ponds during the heat of summer much lower than that of

lined ponds This will both limit the number of fish that can survive in the pond and almost

certainly13 increases stress13 of these13 fish potentially13 reducing growth13 The DO crashes also13

48

13

limit the amount of feed hatchery managers can give fish in these ponds sometimes for

days or weeks at a time which further reduces growth during warm13 weather

Our data13 suggests that13 growth rates at the Bubbling13 Ponds Fish Hatchery are likely

as high as possible given13 the pond densities required to meet production goals and the Ich-shy‐

infested water that feeds the facility Sorting practices are successful in helping as many

fish as possible reach stocking length as fast as possible Unlined ponds may be able to

grow13 large13 fish at low13 densities13 but whatever factors allow13 for that13 growth are not13 able to

overcome high fish density The removal of invasive13 fis that act as13 a host for the13 parasite13

Ich fish from13 the Bubbling13 Ponds spring13 allowed the highest13 growth rate at 032 mmday13

(96 mmmonth) but that growth rate decreased again as Ich re-shy‐infested13 the13 hatchery13

Consistently13 achieving13 growth13 rates13 as high or substantially13 higher than13 this13 will likely13

require13 significant changes in rearing practices that may not be practical in order to13 reach13

numerical production13 goals

Two major changes that might result in higher growth rates are substantially

reducing fish density and modifying the way spring water is delivered to the facility (via

either repeated chemical treatments or enclosed concrete water diversions) to eliminate

Ich from13 the hatchery source water Other potential changes not address by our work

include13 flow-shy‐training razorbacks much previous literature including MSCP-shy‐funded13 work

on razorback suckers13 suggests13 that fish growing13 in flowing water will grow13 faster than fish

in still water (Jorgensen and Jobling 1994) Furthermore there are a wide variety of

potential benefits associated with growing13 fish13 in flowing13 water in addition13 to increased

growth13 rates13 (Davidson13 199713 Castro13 et al13 2011) Another option13 for increasing13 growth13

rates13 include13 changing to13 intensive13 culture13 in large circular13 tanks

Finally given that the stocking of smaller razorbacks has met with very little

success13 perhaps13 BPH13 goals13 could13 be13 changed from13 producing 12000 fish at 300+ mm per

year to a smaller number of very large fish each year Growing fewer larger fish could

potentially be accomplished in the same time frame as more smaller fish but a better

understanding13 of how density13 alters growth13 rate13 would13 be13 required to13 be13 confident of this

49

13

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower13 Colorado13 River Multi-shy‐Species13

Conservation Program13 (LCRMSCP) under Work Task C10 We13 thank Ty Wolters13 Tom13

Burke13 and Eric13 Volkman for their support of this research and Frank Agygos and Dave

Billingsly13 of the Bubbling13 Ponds Fish Hatchery13 for their willingness to participate in13 this

research13 and13 for their technical assistance We also thank the LCRMSCP fish group from13

Boulder City13 NV for their assistance with harvesting13 ponds and tagging13 fish13

50

13

Literature13 CitedAnders P J 1998 Conservation aquaculture and endangered species can objective science13

prevail13 over risk13 anxiety Fisheries 23(11) 28-shy‐31

Anderson R O and R M Nuemann 1996 Length weight and associated structural indicesPages 447 ndash 482 in B R Murphy13 and D13 W Willis13 editors13 Fisheries techniques13 2ndedtion American Fisheries13 Society13 Bethesda13 Maryland

Bain M B J T Finn and H E Brooks 1988 Streamflow regulation and fish communitystructure13 Ecology13 69382-shy‐392

Bays J H Zarbock R Whitman and T Murphy 2005 Conceptual design and managementof native13 fish refugia on the13 lower13 Colorado13 River In13 CL Spring13 and13 S Leoneditors Proceedings of two symposia Restoring native fish to the lower ColoradoRiver13 interactions13 of native and non-shy‐native13 fishes 13ndash1413 July13 1999 Las13 Vegas13 Nevada13 Restoring13 natural function within a modified riverine environment thelower Colorado River13 8ndash913 July13 1998 U S Fish and13 Wildlife13 Service Southwestern13 Region Albuquerque New Mexico Pages 167-shy‐177

Bertalanffy L Von 1957 Quantitative laws in metabolism13 and growth13 Q Rev Biology 32217 ndash 231

Bingham T B Scheer and C McAda 2003 Propagation facilities in Grand Valley (24 RoadHatchery Horsethief13 Ponds and13 grow-shy‐out ponds) for captive13 rearing13 ofendangered13 fishes for the13 upper13 Colorado13 River basin13 Colorado River RecoveryProgram FY2003 annual project report13 US Fish and13 Wildlife13 Service GrandJunction13 4pp

Birchell G J and K Christopherson 2004 Survival growth and recruitment of larval andjuvenile razorback13 sucker (Xyrauchen texanus) introduced13 into13 floodplain13 depressions13 of the13 Green River Utah13 Final report13 Upper13 Colorado13 RiverEndangered Fish Recovery Program13 Project No C-shy‐6RZ Publication Number 04-shy‐1513 Utah13 Division of Wildlife13 Resources Salt Lake13 City13 Utah13 67 pages

Brannon E L 1993 The perpetual oversight of hatchery programs Fishery Research 1819-shy‐27

Brett J R 1979 Environmental Factors and growth pages 599-shy‐67513 InW S Hoar13 D13 J13 Randall and J R Brett (eds) Fish Physiology Volume 8 Bioenergetics and GrowthAcademic Press New York

Brooks J E 1986 Annual reintroduction and monitoring report for razorback suckerXyrauchen texanus in the Gila River Basin Arizona 1985 US Fish and WildlifeService13 Offices of Endangered13 Species and Fishery13 Resources Albuquerque 23 pp

51

13

Brunson13 R E and K D13 Christopherson13 200513 Larval13 razorback13 sucker and bonytailsurvival and13 growth13 in the13 presence13 of nonnative13 fish in the13 Baeser13 floodplainwetland of the middle Green River Final report prepared for Upper13 Colorado RiverBasin Endangered Fish Recovery Program Project No C-shy‐6-shy‐rz-shy‐bt Publication13 No 05-shy‐26 Utah13 Division of Wildlife13 Resources13 Vernal13 32 pp

Bulkley R V and R Pimentel 1983 Temperature preference and avoidance by adultrazorback suckers Transactions of the American Fisheries Society 112601-shy‐607

Burke13 T13 199513 Rearing13 wild razorback13 sucker larvae in13 lake-shy‐side13 backwaters13 LakeMohave ArizonaNevada Proceedings of the Desert Fishes Council 2635

Busacker G P I R Adelman and E M Goolish13 199013 Growth13 Pages 363 ndash 387 in C BSchreck and p B Moyle editors Methods for fish biology American FisheriesSociety Bethesda Maryland

Castro V B Grisdale-shy‐Helland S J Helland T Kristensen S M Jorgensen J Helgrud13 GClaireaux A P Farrell A Krasnov and H Takle 2011 Aerobic training stimulatesgrowth and promotes disease resistance in Atlantic salmon (Salmo salar)Comparative Biochemistry and Physiology -shy‐ Part A Molecular amp IntegrativePhysiology13 160(2) 278-shy‐290

Czapla T E 2002 Facilities plan for the production of endangered fishes to meet statestocking13 plans13 as13 part of the13 Upper13 Colorado13 River Endangered13 Fish RecoveryProgram Upper Colorado River Basin Recovery Implementation Program US Fishand Wildlife Service13 Denver13 9 pp

Davidson W 1997 The effects13 of exercise13 training on teleost fish a review of recentliterature Comput Biochem Physiol 117A67ndash75

Figiel Jr C R 2005 Annual report fiscal year 2004 Willow Beach National13 Fish HatcheryUS Fish and Wildlife13 Service Willow Beach 17 pp

Figiel Jr C R M E Ulibarri G Carmichael J Seals and J N Hanson 2005 Intensive13 fish13 culture of warmwater native fishes at a coldwater fish hatchery Pages 164-shy‐16613 inProceedings of two symposia restoring native fish to the lower Colorado13 River13 interaction13 of native13 and13 non-shy‐native13 fishes July13 13-shy‐1413 1999 Las Vegas Nevada USFish and Wildlife Service Southwest Region Albuquerque New Mexico

Gerking13 S D 1978 Ecology of freshwater fish13 production13 Halstead Press13 New13 York

Gustafson W and Q Bradwisch 2000 Wahweap operation and maintenance -shy‐-shy‐ UtahColorado River Recovery Program FY 2000 annual project report Project No 29cUtah13 Division of Wildlife13 Resources Page AZ 3pp

52

13

Hamman R L 1985 Induced spawning of hatchery-shy‐reared13 razorback sucker ProgressivFish Culturist 47(3) 187-shy‐189

Hanson J N 1996 Annual report fiscal year 1996 Willow Beach National Fish HatcheryUS Fish and Wildlife Service13 Willow Beach 9pp

Irving D S Seversen and M Montagne 2004 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2004 annual project13 report Report No 29b US Fish and13 Wildlife13 Service Vernal 3pp

Jorgensen E H and13 M Jobling 1994 Feeding and13 growth13 of exercised13 and13 unexercised13 juvenile Atlantic salmon in freshwater and performance after transfer to seawaterAquaculture International 2 154-shy‐164

Kaeding L R and D B Osmundson 198913 Colorado13 Squawfish13 and13 razorback sucker grow-shy‐out pond studies as part of conservation measures for the green mountain andRuedi reservoir water sales Final report for agreement number 6-shy‐AA-shy‐60-shy‐00150

Koebele13 B P13 198513 Growth and the size hierarchy effect an experimental assessment ofthree proposed mechanisms activity differences disproportional food acquisition13 pysiological stress Environmental Biology of Fishes 12 181-shy‐188

Kretschmann A E and L L Leslie 2006 Razorback sucker (Xyrauchen texanus) status13 reproduction and recruitment in Senator Wash Reservoir CA Final Report13 to USBurea of Reclamation Cooperative Agreement No 00-shy‐FG-shy‐34-shy‐ 0009 p 32 ArizonaGame and Fish Department Phoenix

Marsh13 P13 C13 1987a13 Digestive tract13 contents13 of adult razorback suckers13 in Lake13 MohaveArizona-shy‐Nevada Transactions of the American Fisheries Society 116117-shy‐119

Marsh P C 1987b Native fishes at Buenos Aires National Wildlife Refuge and ArizonaState University Research Park Arizona opportunities for management researchand public13 education13 on13 endangered species13 Proceedings of the Desert13 FishesCouncil 1967-shy‐78

Marsh P C 1994 Rearing native Colorado River fishes in golf course ponds Arizona StateUniversity Tempe 22 + pages

Marsh13 P13 C13 200013 Fish population13 status and evaluation13 in13 the Cibola13 High Levee PondFinal report agreement number 99-shy‐FG-shy‐30-shy‐00051 US Bureau of ReclamationBoulder City13 Nevada13 20 pages

Marsh P C and C A Pacey 1998 Growth of wild adult razorback suckers13 in Lake13 Mohave13 Arizona-shy‐Nevada13 Final report13 US Bureau of Reclamation Boulder City Nevada 25pages + appendices

53

13

Marsh P C B R Kesner and C A Pacey 2005 Repatriation as s management strategy13 to13 conserve a critically13 imperiled fish species North American Journal of FisheriesManagement 25 547-shy‐556

Marsh P C and C A Pacey 2005 Immiscibility of native and non-shy‐native13 fishes Pages 59-shy‐63 inMJ13 Brouder13 CL13 Springer13 and CS13 Leon13 editors13 Proceedings of two13 symposia Restoring native fish to the lower Colorado River interactions of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 NV and13 Restoring natural13 function within a modified riverine environment the lower Colorado River13 July13 8-shy‐913 1998 Las Vegas NV US Fish and13 Wildlife13 Service Southwest Region AlbuquerqueNew Mexico

Marsh13 P13 C13 and J13 E Brooks13 198913 Predation13 by ictalurid catfishes as a deterrent13 toreestablishment of hatchery-shy‐reared13 razorback sucker The Southwestern Naturalist34188-shy‐195

Matthews R A 2005 Ichthyopthirus multifiliis Fouquet and Ichthyopthirosis infreshwater13 teleosts13 Pages13 159-shy‐218 in Advances in Parasitology volume 59 J RBaker R Muller D Rollinson (eds) Academic Press

McCarthy13 M S and W L Minckley 1987 Age estimation for razorback sucker (PiscesCatostomidae) from13 Lake Mohave Arizona and Nevada Journal of the Arizona-shy‐Nevada Academy of Science 2187-shy‐97

Minckley13 W L13 198313 Status of the razorback13 sucker13 Xyrauchen texanus (Abbot)13 in13 thelower Colorado River basin13 The Southwestern13 Naturalist13 28(2) 165-shy‐187

Minckley13 W L13 199113 Native fished of the Grand Canyon13 region an obituary13 Pages 124-shy‐177 in Colorado River ecology and dam13 management National Academy PressWashington13 DC

Minckley13 C13 O and M LaBarbara13 199913 Report13 on13 native fish grow-shy‐out facilities13 at Cibolaand Imperial National Wildlife Refuges 1993-shy‐199513 US Fish and13 Wildlife Service13 Parker Fishery Resources Office Parker Arizona

Modde13 T13 199613 Juvenile razorback sucker (Xyrauchen texanus) in a managed wetlandadjacent13 to the Green13 River13 Great13 Basin13 Naturalist13 56375-shy‐376

Modde T KP Burnham and E J Wick 1996 Population status of the razorback sucker13 inthe middle Green River (USA) Conservation13 biology 10 110-shy‐119

Modde13 T13 and G13 B Haines13 200513 Survival13 and growth of stocked razorback13 sucker andbonytail in multiple floodplain wetlands of the middle Green River under resetconditions13 Final report prepared for Upper Colorado13 River13 Basin RecoveryImplimentation Program US Fish and Wildlife Service Vernal 66 pp

54

13

Modde T Z H Bowen and D C Kitcheyan 2005 Spatial and temporal use of a spawning13 site in the middle Green River by wild hatchery-shy‐reared13 razorback suckers13 Transactions of the American Fisheries Society 134937-shy‐944

Mueller13 G13 199213 The native fish work13 group13 -shy‐ a multiagency endeavor to improve thestatus of the razorback sucker in Lake Mohave AZ-shy‐NV13 Proceedings of the DesertFishes Council 2369

Mueller G 1995 A program13 for maintaining the razorback sucker in Lake MohaveAmerican Fisheries Society Symposium 15127-shy‐135

Mueller13 G13 200613 Ecology of the bonytail13 and razorback13 sucker and the role of offchannelhabitats13 in their13 recovery Scientific13 investigations13 report 2006-shy‐5065 US GeologicalSurvey13 Denver

Mueller G and E Wick 1998 Testing of golf course ponds at Page Arizona for suitability13 as grow-shy‐out facility for razorback sucker using surplus fish from13 Ouray NationalFish Hatchery National Park Service US Fish and13 Wildlife13 Service and UtahDivision of Wildlife13 Resources 28 pages

Mueller13 G13 and T13 Burke13 200513 Survival13 of young13 razorback13 sucker (Xyrauchen texanus) inrelation to13 stocking rates13 (fishha)13 and13 in the presence13 or absence13 of predatorcommunities in Lake Mohave Arizona-shy‐Nevada13 Pages13 155-shy‐16313 in Proceedings of two13 symposia restoring native fish to the lower Colorado River interaction13 of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 Nevada US Fish and Wildlife13 Service Southwest Region Albuquerque New Mexico

Mueller13 G13 J13 Carpenter13 and P13 C13 Marsh13 200413 Cibola13 High Levee Pond annual report 2004US Geological Survey Fort Collins13 Science Center13 Colorado13 and Arizona StateUniversity Tempe 23 pages

Nesler T P K Christopherson J M Hudson C W McAda F Pfeifer and T E Czapla 2003An integrated stocking plan for razorback sucker bonytail and Colorado13 pikeminnow for the Upper Colorado River Endangered Fish Recovery ProgramAddendum13 to State Stocking Plans Upper Colorado River Basin Recovery13 Implementation Program 12 pp

Papoulias13 D and W13 L Minckley13 1992 Effects13 of foo availability13 on survival and growth13 of larval razorback suckers13 in ponds Transactions of the American Fisheries Society121340-shy‐355

Paukert13 C P D L Ward13 P J Sponholtz13 and K13 D Hilwig13 Effects13 of repeated hoopnetting13 on bonytail chub13 Journal of Freshwater13 Ecology13 20(4) 649-shy‐653

Pfeifer F M13 C Baker13 and M13 Montagne13 199913 Propagation13 facilities13 in the13 Grand Valley13 (24 Road13 Hatchery13 Horsethief13 Ponds and13 grow-shy‐out ponds) for captive rearing of

55

13

endangered13 fishes for the13 Upper Colorado13 River Basin13 Colorado13 River Recovery13 Program FY 99 annual project report Project No 29a13 US Fish and Wildlife Service13 Grand13 Junction13 5pp

Pfeifer F S Seversen and M Montagne 2003 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2003 annual reportProject No 29b13 US Fish and Wildlife13 Service Vernal13 4pp

Rabago-shy‐Castro J L Sanchez13 J G Perez-shy‐Castaneda R and13 Gonzalez-shy‐Gonzlez A 2006Effects of the prophylactic use of Romet-shy‐3013 and13 copper13 sulfate13 on growth13 condition13 and feeding13 indicies in13 channel13 catfish (Ictalurus punctatus) Aquaculture 253 343-shy‐349

Reinitz GL L E Orme and F N Hitzel 1979 Variations of body compositio and growth13 among strains of rainbow trout Transactions of the American Fisheries Society 108204-shy‐207

Ruppert13 J13 B P B Holden13 and P D Abate 1999 Age estimation and growth of razorbacksucker13 Xyrauchen texanus in Lake13 Mead Nevada Proceedings13 of the Desert FishesCouncil 3040

Schnoor K D and J Logan 2002 Operation and maintenance of JW Mumma nativeaquatic13 species restoration facility Colorado Colorado River Recovery Program FY2002 annual project report13 Project No 29d Colorado13 Division of Wildlife Alamosa3pp

Salisbury13 L13 1998 Factors13 affecting razorback13 sucker growth13 in Lake13 Mohave backwaters13 MS Thesis13 Unviersity13 of Nevada13 Las13 Vegas

Schooley J13 D13 and P C13 Marsh13 2007 Stocking of endangerdd13 razorback13 suckers13 in thelower Colorado River Basin13 over three decades 1974-shy‐2004 North American Journalof Fisheries Management 27 43-shy‐51

Severson S H H M Tyus and G B Haines 1992 An evaluation of feeds for raisingrazorback sucker Xyrauchen texanus Journal of Applied Aquaculture 155-shy‐65

Toney D P 1974 Observations13 on the13 propagation13 and13 rearing13 of two13 endangered species13 in a hatchery environment Proceedings of the Annual Conference of the Western13 Association of State Game and Fish Commissions 54 252-shy‐259

Tyus H M13 1998 Razorback sucker13 (Xyrauchen texanus) recovery plan13 University13 ofColorado Center for Limnology Boulder13 76 pages

Tyus H M13 and13 S H Severson 1990 Growth13 and13 survival of larval razorback suckers fedfive formulated diets The Progressive Fish Culturist 52197-shy‐200

56

13

Ulibarri M E 2003 Annual report fiscal year 2001 Dexter National Fish Hatchery13 andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 26 pages

Ulibarri M E 2003 Annual report fiscal year 2002 Dexter National Fish Hatchery andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 59 pages

USBR 2006 Lower13 Colorado13 River Multi-shy‐Species Conservation Program final fishaugmentation plan Boulder City 19 pp

USFWS 2002 Razorback sucker (Xyraouchen texanus) recovery goals Amendment andsupplement to the Razorback Sucker Recovery Plan13 US Fish and Wildlife Service13 Region 6 Denver13 Colorado

USFWS 1999 Annual report 1999 Ouray National Fish Hatchery Vernal 25pp

USFWS 2004 Management plan for the big-shy‐river13 fishes of the13 lower13 Colorado13 river basinamendment and supplement to the bonytail humpback chub Coloradopikeminnow and razorback sucker recovery plans

USFWS13 2005 Station13 profile13 of the13 Dexter13 National Fish Hatchery13 and Technology CenterUS Fish and Wildlife13 Service Dexter

Valdez R A P G Mangan R Smith and B Nilson 1982 Upper Colorado River fisheriesinvestigations13 inW H Miller J J Valentine D L Archer H M Tyus R A Valdezand L13 Kaeding13 editors13 Colorado River Fishery13 Project13 Part 2 Field13 investigations13 US Bureau of Reclamation Salt Lake City Utah

WBNFH 2004 Culture methods of the endangered razorback sucker Xyrauchen texanusUS Fish and Wildlife13 Service Willow Beach National Fish Hatchery13 8 pp

Ward D 2008 Effects of disease treatments on growth of razorback sucker ReportSubmitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 Inpartial fulfillment of work task C10 agreement number 06FG30039

Ward13 D13 M Childs and W Persons 2007 Factors13 affecting13 growth13 of razorback sucker13 (Xyrauchen texanus) in captivity Literature review and knowledge assessmentReport Submitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 In partial fulfillment of work task C10 agreement number 06FG30039

57

Appendices

Appendix 1 Survey Questions Survey of Razorback Sucker Culture in the

Southwestern United States

The enclosed survey is being distributed by the Arizona Game and Fish Department to razorback sucker culture facilities throughout

the Southwestern United States The purpose of this survey is to consolidate information regarding culture of this species so that

appropriate facility improvements can be considered for Bubbling Ponds Hatchery in Arizona Specifically we wish to increase

growth rate and production efficiency at the hatchery Information gathered in this survey will be summarized in a final report to US

Bureau of Reclamation in Boulder City NV and disseminated to all facilities that participate in the survey A workshop to discuss

the findings of this study as well as to share general information concerning razorback sucker culture will be organized by the

Arizona Game and Fish Department at the conclusion of this study and all participants will be invited

Thank you for taking the time to fill out this survey Please contact Mike Childs if you have questions or would like to discuss the

survey

Mike Childs

mchildssedonanet

(928) 639-1346

(928) 634-1279

Facility_____________________________________ Date___________________

Contact Phone _____________________________

ContactPerson_______________________________

Contact Email _______________________________

1 Water quality ranges at this culture facility

Season

Spring (Mar-May) Summer (Jun-Aug) Fall (Sept-Nov) Winter (Dec-Feb)

Temperature (C)

PH

DO (mgL)

PO4 (mgL)

TDS (mgL)

Hardness (mgL)

CaCO3

Pathogens

37

13

juvenile mosquitofish were again detected in the spring pond Minnow traps have

subsequently been set daily with several hundred individuals removed To evaluate if Ich

was also again present in the spring we captured 15 mosquitofish from13 the spring pond on

three separate days and placed them13 in an aquaria at 25 degC with 5 longfin dace known to be

free of Ich These fish were monitored for 2 weeks with no signs of Ich developing This

indicates that even though mosquitofish have returned to the spring pond the parasite is no

longer present13 although how13 long13 this condition13 will13 persist13 is unknown13

On May 1113 201013 200 juvenile razorback13 suckers were harvested out13 of Pond 5

upper (2009 year Class from13 Dexter National Fish Hatchery) and were PIT tagged and

placed into Pond 8 to evaluate if growth rates at bubbling ponds hatchery have improved

following the renovation of the spring and the removal of the Ich parasite Unfortunately13

on Sept13 8 2010 Ich was13 again13 detected13 in Pond 8 and the pond was immediately seined

and 74 tagged fish were measured to obtain growth information for the 4-shy‐month period

during13 which13 the13 pond13 was13 Ich-shy‐free13

Figure13 6 Temperatures (degC) in rearingponds 7 and 8 at Bubbling Ponds Hatchery13 from March 2009 ndash March 201013 pond 7(top13 graph)13 and13 pond 8 (Lower13 graph)13 Temperatures recorded with a Hobotempregremote data logger every 3 hours

42

13

Results

Growth in Lined Ponds

Razorback suckers13 that had been13 in13 Pond 8 upper for the13 entire13 year13 grew an13

average of 0263 mmday (789 mmmonth) and razorback suckers that had been in the

pond for 7 months (Oct -shy‐ May) grew13 on13 average of 028 mmday (843 mmmonth) (Figure13

7) These growth13 rates13 did not significantly13 differ Fish density13 in Pond 3 during13 the13

majority of the growth period was13 00032 ndash 00036 fishgallon13 Additionally no13 significant

differences in growth rate were observed between fish smaller than 210 mm TL and fish

larger than 210 mm TL when all recaptured fish were combined

We also measured the growth rate of very large fish in a lined pond On Jan13 2513 201013

156 adult fish with PIT tags were recovered from13 Pond 3 upper13 These fish were13 in the13

pond for 257 days and experienced an average13 growth13 rate13 of 024mmday or 73

mmmonth (Figure13 7)13 This growth13 rate13 is slightly13 lower13 than13 the13 average13 growth13 rate13

observed13 at Bubbling13 Ponds Hatchery in other studies (0275 mmday 825 mmmonth)

but may not be biologically meaningful We would expect larger13 fish to13 have13 reduced

growth rates according to a typical Von Bertalanfy growth model (Bertalanffy 1957) but it

appears that13 over the size range we evaluated (300 -shy‐ 450 mm TL) growth rates have not

slowed significantly compared to that of smaller13 fish grown at Bubbling Ponds13 Hatchery

Growth13 of razorback suckers13 is known13 to13 slow as13 fish reach13 larger13 sizes but it appears13 this13

reduced growth rate may not really start to be biologically meaningful at Bubbling Ponds

Hatchery13 until razorback suckers13 exceed 450 mm TL

Growth in unlined ponds

Growth13 rates13 for the13 fish recaptured13 during13 the Pond 1 lower13 thinning13 (120 days13 in

the pond) was 024 plusmn 003 mmday (729 plusmn 090 mmmonth) (Figure13 8)13 Fish13 that were13 in

the pond for nearly the entire year grew13 an13 average13 of 024 plusmn 001 mmday (726 plusmn 027

mmmonth) These growth rates are surprisingly the lowest measured growth rates for

any part of our study and differ significantly from13 every other measured growth rate

except very large13 fish (Figure13 9)13 Separating13 out13 large fish that13 were in13 the pond for the

entire year makes no difference fish that were added to the pond at TL lt300 mm grew

43

13

Gro

wth

Rat

e (m

md

ay)

020

026

032

0244 plusmn 001 mmday (733 plusmn 028 mmmonth) and and those with TL gt= 300 mm at the

start of the experiment grew 022 plusmn 003 mmday (651 plusmn 101 mmmonth)

Razorback Growth Rates in Lined Ponds

Figure 7 Growth ofrazorback suckers in(mmday plusmn standard error)in Pond 8 upper in 2008-shy‐2009 An ANOVA did notdetect any significantdifferences

7 Months Full Year 300+ mm fish

Effects of sorting on growth

One hundred and seventy five tagged razorback suckers were recovered from13 Pond

8 upper13 on March13 24 2010 (378 days13 of growth)13 These were13 the13 larger sorted13 fish (gt140

mm TL) that came out of Pond13 5 on March13 11 2009 One13 hundred and13 twenty13 two13 tagged13

razorback suckers were also recovered from13 Pond13 7 upper on March13 31 2010 (385 days13 of

growth)13 These were13 the13 smaller sorted13 fish (lt140 mm TL) that came out of Pond13 5 on

March 1113 200913 No significant differences in growth rate (mmday) were observed among

larger fish in Pond 8 and smaller fish in Pond 7 (pgt005 ANOVA) (Figure 10)13 indicating

that13 sorting may have helped to offset the original slower growth trajectory of the smaller

fish Temperatures of Ponds 7 and 8 upper remained similar throughout the year13 (Figure

5)

44

13

13

13

Gro

wth

Rat

e (m

md

ay)

Gro

wth

Rat

e (m

md

ay)

020

026

032

020

026

032

Razorback Growth in an Unlined Pond

Figure 8 Growth of razorbacksuckers (mmday plusmn standard error) in Pond 1 lower (an unlined pond)in 2010-shy‐2011 An ANOVA did notdetect any significant differences

6 Months 12 Months lt 300 mm Fish 300+ mm Fish Growth Growth

Lined vs Earthen Ponds 1 year of growth

Figure 9 Growth of razorbacksuckers (mmday plusmn standard error) in lined and unlined ponds A t-shy‐test13 did not detect a significantdifference

Lined Pond Unlined Pond 1 Yr Growth 1 Yr Growth

45

13

Effect of Sorting G

row

th R

ate

(mm

day

) G

row

th R

ate

(mm

day

)

032

020

026

032

020

026

Smaller Fish Larger Fish

Effect of Ich

Figure 10 Average growthof razorback suckers(mmday plusmn standard error)that were size-shy‐sorted intosmall fish (pond 7) and largefish (pond 8) populations At-shy‐test did not detect asignificant difference

Figure 11 Average growth ofrazorback suckers (mmday plusmnstandard error) after Ich wasremovd from the hatcheryrsquos springand after Ich was again detected inthe pond The growth rate withoutIch is significantly higher than boththe rate after Ich and the ourstudyrsquos average annual growth ratein lined ponds (ANOVA p =00003)

Growth without Ich Growth With Ich Average Annual 4 months 4 months Growth Rate

46

13

Effect of Ich on razorback sucker growth rates

Seventy-shy‐four13 tagged13 razorback suckers13 were13 recovered from13 Pond 8 on September

15 2010 These fish had13 been13 in the pond for 4 months and experienced a growth rate of

032 mmday or 97 mmmonth (Figure13 11)13 This growth13 rate13 is significantly higher (p =

005 two sample t-shy‐test) than the mean growth rate for the same group13 of tagged fish after

Ich detection (022 mmday or 65 mmmonth) and significantly higher than any other

individual growth13 rates13 observed13 to13 date13 at Bubbling13 Ponds Hatchery13 (Figure13 11)13 If this13

growth13 rate13 were13 extended throughout13 the entire13 year13 fish on average from13 Ich-shy‐free13 ponds13

would be 16 mm longer than fish from13 ponds infested with Ich Studies conducted at

Bubbling Ponds hatchery in 2008 (Ward 2008) did not reveal any effects of the treatment

chemicals on razorback sucker growth rates so it13 is likely that13 the parasite outbreaks

themselves are causing reducing growth rates rather than the chemicals used to treat the

parasites13

Conclusions

Our results suggest that under typical hatchery operations (maximizing number of

fish produced)13 the growth13 rate13 of razorback13 suckers13 is relatively13 consistent at Bubbling13

Ponds hatchery13 at 02-shy‐03 mmday (6-shy‐9 mmmonth)13 but is lower than growth13 rates13 at

other13 facilities (02 ndash 18 mmday Ward et al 2007)13 This growth13 rate13 has13 been13 constant in

both lined and unlined ponds and at all fish densities we were able to measure To achieve13

growth13 rates13 substantially higher than this will likely require13 significant changes in rearing

practices that may not be practical in order to reach numerical production13 goals

Temperature is a key variable in fish growth but seasonal growth patterns

described13 above13 (Figure13 5) demonstrate that water temperatures are high enough in

winter to maintain razorback growth Differences in water temperature by season

currently13 do not fluctuate more than 10degC at Bubbling Ponds because of the continuous

supply of water flowing through each pond (approx 225 gallonsmin) These high water

flows appear to keep pond temperatures within the thermal preference13 for razorback

suckers13 (1213 -shy‐ 28 degC Bulkley and Pimentel 1983) throughout the entire year with

temperatures rarely dropping13 below 16deg13 C (Figures 513 6)13

47

13

Fish density is another key variable in fish growth and though the number of fish in

a pond during our study ranged from13 3000 to 700013 fish we13 did not find any13 correlation13

between13 density and growth rate13 This might yield two conclusions First13 razorback

growth13 may be changed equally13 by13 densities13 at the13 hatchery13 (ie13 a density13 of 3000 fish in a

pond is as stressful13 for razorbacks as a density13 of 7000 fish) An alternative is that other

factors13 such as disease outbreaks have13 stronger13 control over fish growth13 than13 density13

Fish density13 would13 have13 to13 be13 experimentally manipulated to test13 this13 and hatchery

operations (producing the maximum13 number of fish) prevented our manipulating density13

in ponds for this13 work The trouble with manipulating density demonstrates the difficulties

associated with changing13 hatchery13 practices experimenting with density would have

prevented BPH from13 meeting13 production13 goals Given that the stocking of smaller

razorbacks has met with very little success perhaps BPH goals could be changed from13

producing 12000 fish at 300+ mm per year to a smaller number of very large fish each

year Growing13 fewer13 larger13 fish could potentially be accomplished in the same time frame

as more smaller fish but a better understanding of how density alters growth rate would

be required to be confident13 of this

The very slow growth13 in the13 earthen13 unlined13 Pond 1 lower13 was very surprising We13

had13 anticipated13 that the13 diversified diet13 cover and13 other13 habitat features13 provided by13

unlined ponds would yield dramatically increased growth rates However these traits were

not enough to offset high fish densities and in fact the unlined pond in our study13 suffered

mortality to bring densities down to that observed normally in lined ponds

Our data13 suggest13 that razorbacks13 sucker13 growth13 rates13 are13 higher in lined13 ponds13

However we13 think the reasons13 for the13 very slow growth we observed13 in the13 unlined13 pond13

in our study13 is instead13 linked13 to13 the13 usage13 of Pond 1 lower13 during13 the13 study13 rather13 than13

intrinsic13 slow growth13 in earthen13 ponds First the pond was at extremely high density for at

least part of the study The volume of Pond 1 lower has not been estimated but hatchery

managers suggest 1500-shy‐2000 fish is an appropriate number of individuals so this pond

was at a very high density for much of the experiment Second dissolved oxygen is often

very low in the13 large13 earthen13 ponds during the heat of summer much lower than that of

lined ponds This will both limit the number of fish that can survive in the pond and almost

certainly13 increases stress13 of these13 fish potentially13 reducing growth13 The DO crashes also13

48

13

limit the amount of feed hatchery managers can give fish in these ponds sometimes for

days or weeks at a time which further reduces growth during warm13 weather

Our data13 suggests that13 growth rates at the Bubbling13 Ponds Fish Hatchery are likely

as high as possible given13 the pond densities required to meet production goals and the Ich-shy‐

infested water that feeds the facility Sorting practices are successful in helping as many

fish as possible reach stocking length as fast as possible Unlined ponds may be able to

grow13 large13 fish at low13 densities13 but whatever factors allow13 for that13 growth are not13 able to

overcome high fish density The removal of invasive13 fis that act as13 a host for the13 parasite13

Ich fish from13 the Bubbling13 Ponds spring13 allowed the highest13 growth rate at 032 mmday13

(96 mmmonth) but that growth rate decreased again as Ich re-shy‐infested13 the13 hatchery13

Consistently13 achieving13 growth13 rates13 as high or substantially13 higher than13 this13 will likely13

require13 significant changes in rearing practices that may not be practical in order to13 reach13

numerical production13 goals

Two major changes that might result in higher growth rates are substantially

reducing fish density and modifying the way spring water is delivered to the facility (via

either repeated chemical treatments or enclosed concrete water diversions) to eliminate

Ich from13 the hatchery source water Other potential changes not address by our work

include13 flow-shy‐training razorbacks much previous literature including MSCP-shy‐funded13 work

on razorback suckers13 suggests13 that fish growing13 in flowing water will grow13 faster than fish

in still water (Jorgensen and Jobling 1994) Furthermore there are a wide variety of

potential benefits associated with growing13 fish13 in flowing13 water in addition13 to increased

growth13 rates13 (Davidson13 199713 Castro13 et al13 2011) Another option13 for increasing13 growth13

rates13 include13 changing to13 intensive13 culture13 in large circular13 tanks

Finally given that the stocking of smaller razorbacks has met with very little

success13 perhaps13 BPH13 goals13 could13 be13 changed from13 producing 12000 fish at 300+ mm per

year to a smaller number of very large fish each year Growing fewer larger fish could

potentially be accomplished in the same time frame as more smaller fish but a better

understanding13 of how density13 alters growth13 rate13 would13 be13 required to13 be13 confident of this

49

13

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower13 Colorado13 River Multi-shy‐Species13

Conservation Program13 (LCRMSCP) under Work Task C10 We13 thank Ty Wolters13 Tom13

Burke13 and Eric13 Volkman for their support of this research and Frank Agygos and Dave

Billingsly13 of the Bubbling13 Ponds Fish Hatchery13 for their willingness to participate in13 this

research13 and13 for their technical assistance We also thank the LCRMSCP fish group from13

Boulder City13 NV for their assistance with harvesting13 ponds and tagging13 fish13

50

13

Literature13 CitedAnders P J 1998 Conservation aquaculture and endangered species can objective science13

prevail13 over risk13 anxiety Fisheries 23(11) 28-shy‐31

Anderson R O and R M Nuemann 1996 Length weight and associated structural indicesPages 447 ndash 482 in B R Murphy13 and D13 W Willis13 editors13 Fisheries techniques13 2ndedtion American Fisheries13 Society13 Bethesda13 Maryland

Bain M B J T Finn and H E Brooks 1988 Streamflow regulation and fish communitystructure13 Ecology13 69382-shy‐392

Bays J H Zarbock R Whitman and T Murphy 2005 Conceptual design and managementof native13 fish refugia on the13 lower13 Colorado13 River In13 CL Spring13 and13 S Leoneditors Proceedings of two symposia Restoring native fish to the lower ColoradoRiver13 interactions13 of native and non-shy‐native13 fishes 13ndash1413 July13 1999 Las13 Vegas13 Nevada13 Restoring13 natural function within a modified riverine environment thelower Colorado River13 8ndash913 July13 1998 U S Fish and13 Wildlife13 Service Southwestern13 Region Albuquerque New Mexico Pages 167-shy‐177

Bertalanffy L Von 1957 Quantitative laws in metabolism13 and growth13 Q Rev Biology 32217 ndash 231

Bingham T B Scheer and C McAda 2003 Propagation facilities in Grand Valley (24 RoadHatchery Horsethief13 Ponds and13 grow-shy‐out ponds) for captive13 rearing13 ofendangered13 fishes for the13 upper13 Colorado13 River basin13 Colorado River RecoveryProgram FY2003 annual project report13 US Fish and13 Wildlife13 Service GrandJunction13 4pp

Birchell G J and K Christopherson 2004 Survival growth and recruitment of larval andjuvenile razorback13 sucker (Xyrauchen texanus) introduced13 into13 floodplain13 depressions13 of the13 Green River Utah13 Final report13 Upper13 Colorado13 RiverEndangered Fish Recovery Program13 Project No C-shy‐6RZ Publication Number 04-shy‐1513 Utah13 Division of Wildlife13 Resources Salt Lake13 City13 Utah13 67 pages

Brannon E L 1993 The perpetual oversight of hatchery programs Fishery Research 1819-shy‐27

Brett J R 1979 Environmental Factors and growth pages 599-shy‐67513 InW S Hoar13 D13 J13 Randall and J R Brett (eds) Fish Physiology Volume 8 Bioenergetics and GrowthAcademic Press New York

Brooks J E 1986 Annual reintroduction and monitoring report for razorback suckerXyrauchen texanus in the Gila River Basin Arizona 1985 US Fish and WildlifeService13 Offices of Endangered13 Species and Fishery13 Resources Albuquerque 23 pp

51

13

Brunson13 R E and K D13 Christopherson13 200513 Larval13 razorback13 sucker and bonytailsurvival and13 growth13 in the13 presence13 of nonnative13 fish in the13 Baeser13 floodplainwetland of the middle Green River Final report prepared for Upper13 Colorado RiverBasin Endangered Fish Recovery Program Project No C-shy‐6-shy‐rz-shy‐bt Publication13 No 05-shy‐26 Utah13 Division of Wildlife13 Resources13 Vernal13 32 pp

Bulkley R V and R Pimentel 1983 Temperature preference and avoidance by adultrazorback suckers Transactions of the American Fisheries Society 112601-shy‐607

Burke13 T13 199513 Rearing13 wild razorback13 sucker larvae in13 lake-shy‐side13 backwaters13 LakeMohave ArizonaNevada Proceedings of the Desert Fishes Council 2635

Busacker G P I R Adelman and E M Goolish13 199013 Growth13 Pages 363 ndash 387 in C BSchreck and p B Moyle editors Methods for fish biology American FisheriesSociety Bethesda Maryland

Castro V B Grisdale-shy‐Helland S J Helland T Kristensen S M Jorgensen J Helgrud13 GClaireaux A P Farrell A Krasnov and H Takle 2011 Aerobic training stimulatesgrowth and promotes disease resistance in Atlantic salmon (Salmo salar)Comparative Biochemistry and Physiology -shy‐ Part A Molecular amp IntegrativePhysiology13 160(2) 278-shy‐290

Czapla T E 2002 Facilities plan for the production of endangered fishes to meet statestocking13 plans13 as13 part of the13 Upper13 Colorado13 River Endangered13 Fish RecoveryProgram Upper Colorado River Basin Recovery Implementation Program US Fishand Wildlife Service13 Denver13 9 pp

Davidson W 1997 The effects13 of exercise13 training on teleost fish a review of recentliterature Comput Biochem Physiol 117A67ndash75

Figiel Jr C R 2005 Annual report fiscal year 2004 Willow Beach National13 Fish HatcheryUS Fish and Wildlife13 Service Willow Beach 17 pp

Figiel Jr C R M E Ulibarri G Carmichael J Seals and J N Hanson 2005 Intensive13 fish13 culture of warmwater native fishes at a coldwater fish hatchery Pages 164-shy‐16613 inProceedings of two symposia restoring native fish to the lower Colorado13 River13 interaction13 of native13 and13 non-shy‐native13 fishes July13 13-shy‐1413 1999 Las Vegas Nevada USFish and Wildlife Service Southwest Region Albuquerque New Mexico

Gerking13 S D 1978 Ecology of freshwater fish13 production13 Halstead Press13 New13 York

Gustafson W and Q Bradwisch 2000 Wahweap operation and maintenance -shy‐-shy‐ UtahColorado River Recovery Program FY 2000 annual project report Project No 29cUtah13 Division of Wildlife13 Resources Page AZ 3pp

52

13

Hamman R L 1985 Induced spawning of hatchery-shy‐reared13 razorback sucker ProgressivFish Culturist 47(3) 187-shy‐189

Hanson J N 1996 Annual report fiscal year 1996 Willow Beach National Fish HatcheryUS Fish and Wildlife Service13 Willow Beach 9pp

Irving D S Seversen and M Montagne 2004 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2004 annual project13 report Report No 29b US Fish and13 Wildlife13 Service Vernal 3pp

Jorgensen E H and13 M Jobling 1994 Feeding and13 growth13 of exercised13 and13 unexercised13 juvenile Atlantic salmon in freshwater and performance after transfer to seawaterAquaculture International 2 154-shy‐164

Kaeding L R and D B Osmundson 198913 Colorado13 Squawfish13 and13 razorback sucker grow-shy‐out pond studies as part of conservation measures for the green mountain andRuedi reservoir water sales Final report for agreement number 6-shy‐AA-shy‐60-shy‐00150

Koebele13 B P13 198513 Growth and the size hierarchy effect an experimental assessment ofthree proposed mechanisms activity differences disproportional food acquisition13 pysiological stress Environmental Biology of Fishes 12 181-shy‐188

Kretschmann A E and L L Leslie 2006 Razorback sucker (Xyrauchen texanus) status13 reproduction and recruitment in Senator Wash Reservoir CA Final Report13 to USBurea of Reclamation Cooperative Agreement No 00-shy‐FG-shy‐34-shy‐ 0009 p 32 ArizonaGame and Fish Department Phoenix

Marsh13 P13 C13 1987a13 Digestive tract13 contents13 of adult razorback suckers13 in Lake13 MohaveArizona-shy‐Nevada Transactions of the American Fisheries Society 116117-shy‐119

Marsh P C 1987b Native fishes at Buenos Aires National Wildlife Refuge and ArizonaState University Research Park Arizona opportunities for management researchand public13 education13 on13 endangered species13 Proceedings of the Desert13 FishesCouncil 1967-shy‐78

Marsh P C 1994 Rearing native Colorado River fishes in golf course ponds Arizona StateUniversity Tempe 22 + pages

Marsh13 P13 C13 200013 Fish population13 status and evaluation13 in13 the Cibola13 High Levee PondFinal report agreement number 99-shy‐FG-shy‐30-shy‐00051 US Bureau of ReclamationBoulder City13 Nevada13 20 pages

Marsh P C and C A Pacey 1998 Growth of wild adult razorback suckers13 in Lake13 Mohave13 Arizona-shy‐Nevada13 Final report13 US Bureau of Reclamation Boulder City Nevada 25pages + appendices

53

13

Marsh P C B R Kesner and C A Pacey 2005 Repatriation as s management strategy13 to13 conserve a critically13 imperiled fish species North American Journal of FisheriesManagement 25 547-shy‐556

Marsh P C and C A Pacey 2005 Immiscibility of native and non-shy‐native13 fishes Pages 59-shy‐63 inMJ13 Brouder13 CL13 Springer13 and CS13 Leon13 editors13 Proceedings of two13 symposia Restoring native fish to the lower Colorado River interactions of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 NV and13 Restoring natural13 function within a modified riverine environment the lower Colorado River13 July13 8-shy‐913 1998 Las Vegas NV US Fish and13 Wildlife13 Service Southwest Region AlbuquerqueNew Mexico

Marsh13 P13 C13 and J13 E Brooks13 198913 Predation13 by ictalurid catfishes as a deterrent13 toreestablishment of hatchery-shy‐reared13 razorback sucker The Southwestern Naturalist34188-shy‐195

Matthews R A 2005 Ichthyopthirus multifiliis Fouquet and Ichthyopthirosis infreshwater13 teleosts13 Pages13 159-shy‐218 in Advances in Parasitology volume 59 J RBaker R Muller D Rollinson (eds) Academic Press

McCarthy13 M S and W L Minckley 1987 Age estimation for razorback sucker (PiscesCatostomidae) from13 Lake Mohave Arizona and Nevada Journal of the Arizona-shy‐Nevada Academy of Science 2187-shy‐97

Minckley13 W L13 198313 Status of the razorback13 sucker13 Xyrauchen texanus (Abbot)13 in13 thelower Colorado River basin13 The Southwestern13 Naturalist13 28(2) 165-shy‐187

Minckley13 W L13 199113 Native fished of the Grand Canyon13 region an obituary13 Pages 124-shy‐177 in Colorado River ecology and dam13 management National Academy PressWashington13 DC

Minckley13 C13 O and M LaBarbara13 199913 Report13 on13 native fish grow-shy‐out facilities13 at Cibolaand Imperial National Wildlife Refuges 1993-shy‐199513 US Fish and13 Wildlife Service13 Parker Fishery Resources Office Parker Arizona

Modde13 T13 199613 Juvenile razorback sucker (Xyrauchen texanus) in a managed wetlandadjacent13 to the Green13 River13 Great13 Basin13 Naturalist13 56375-shy‐376

Modde T KP Burnham and E J Wick 1996 Population status of the razorback sucker13 inthe middle Green River (USA) Conservation13 biology 10 110-shy‐119

Modde13 T13 and G13 B Haines13 200513 Survival13 and growth of stocked razorback13 sucker andbonytail in multiple floodplain wetlands of the middle Green River under resetconditions13 Final report prepared for Upper Colorado13 River13 Basin RecoveryImplimentation Program US Fish and Wildlife Service Vernal 66 pp

54

13

Modde T Z H Bowen and D C Kitcheyan 2005 Spatial and temporal use of a spawning13 site in the middle Green River by wild hatchery-shy‐reared13 razorback suckers13 Transactions of the American Fisheries Society 134937-shy‐944

Mueller13 G13 199213 The native fish work13 group13 -shy‐ a multiagency endeavor to improve thestatus of the razorback sucker in Lake Mohave AZ-shy‐NV13 Proceedings of the DesertFishes Council 2369

Mueller G 1995 A program13 for maintaining the razorback sucker in Lake MohaveAmerican Fisheries Society Symposium 15127-shy‐135

Mueller13 G13 200613 Ecology of the bonytail13 and razorback13 sucker and the role of offchannelhabitats13 in their13 recovery Scientific13 investigations13 report 2006-shy‐5065 US GeologicalSurvey13 Denver

Mueller G and E Wick 1998 Testing of golf course ponds at Page Arizona for suitability13 as grow-shy‐out facility for razorback sucker using surplus fish from13 Ouray NationalFish Hatchery National Park Service US Fish and13 Wildlife13 Service and UtahDivision of Wildlife13 Resources 28 pages

Mueller13 G13 and T13 Burke13 200513 Survival13 of young13 razorback13 sucker (Xyrauchen texanus) inrelation to13 stocking rates13 (fishha)13 and13 in the presence13 or absence13 of predatorcommunities in Lake Mohave Arizona-shy‐Nevada13 Pages13 155-shy‐16313 in Proceedings of two13 symposia restoring native fish to the lower Colorado River interaction13 of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 Nevada US Fish and Wildlife13 Service Southwest Region Albuquerque New Mexico

Mueller13 G13 J13 Carpenter13 and P13 C13 Marsh13 200413 Cibola13 High Levee Pond annual report 2004US Geological Survey Fort Collins13 Science Center13 Colorado13 and Arizona StateUniversity Tempe 23 pages

Nesler T P K Christopherson J M Hudson C W McAda F Pfeifer and T E Czapla 2003An integrated stocking plan for razorback sucker bonytail and Colorado13 pikeminnow for the Upper Colorado River Endangered Fish Recovery ProgramAddendum13 to State Stocking Plans Upper Colorado River Basin Recovery13 Implementation Program 12 pp

Papoulias13 D and W13 L Minckley13 1992 Effects13 of foo availability13 on survival and growth13 of larval razorback suckers13 in ponds Transactions of the American Fisheries Society121340-shy‐355

Paukert13 C P D L Ward13 P J Sponholtz13 and K13 D Hilwig13 Effects13 of repeated hoopnetting13 on bonytail chub13 Journal of Freshwater13 Ecology13 20(4) 649-shy‐653

Pfeifer F M13 C Baker13 and M13 Montagne13 199913 Propagation13 facilities13 in the13 Grand Valley13 (24 Road13 Hatchery13 Horsethief13 Ponds and13 grow-shy‐out ponds) for captive rearing of

55

13

endangered13 fishes for the13 Upper Colorado13 River Basin13 Colorado13 River Recovery13 Program FY 99 annual project report Project No 29a13 US Fish and Wildlife Service13 Grand13 Junction13 5pp

Pfeifer F S Seversen and M Montagne 2003 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2003 annual reportProject No 29b13 US Fish and Wildlife13 Service Vernal13 4pp

Rabago-shy‐Castro J L Sanchez13 J G Perez-shy‐Castaneda R and13 Gonzalez-shy‐Gonzlez A 2006Effects of the prophylactic use of Romet-shy‐3013 and13 copper13 sulfate13 on growth13 condition13 and feeding13 indicies in13 channel13 catfish (Ictalurus punctatus) Aquaculture 253 343-shy‐349

Reinitz GL L E Orme and F N Hitzel 1979 Variations of body compositio and growth13 among strains of rainbow trout Transactions of the American Fisheries Society 108204-shy‐207

Ruppert13 J13 B P B Holden13 and P D Abate 1999 Age estimation and growth of razorbacksucker13 Xyrauchen texanus in Lake13 Mead Nevada Proceedings13 of the Desert FishesCouncil 3040

Schnoor K D and J Logan 2002 Operation and maintenance of JW Mumma nativeaquatic13 species restoration facility Colorado Colorado River Recovery Program FY2002 annual project report13 Project No 29d Colorado13 Division of Wildlife Alamosa3pp

Salisbury13 L13 1998 Factors13 affecting razorback13 sucker growth13 in Lake13 Mohave backwaters13 MS Thesis13 Unviersity13 of Nevada13 Las13 Vegas

Schooley J13 D13 and P C13 Marsh13 2007 Stocking of endangerdd13 razorback13 suckers13 in thelower Colorado River Basin13 over three decades 1974-shy‐2004 North American Journalof Fisheries Management 27 43-shy‐51

Severson S H H M Tyus and G B Haines 1992 An evaluation of feeds for raisingrazorback sucker Xyrauchen texanus Journal of Applied Aquaculture 155-shy‐65

Toney D P 1974 Observations13 on the13 propagation13 and13 rearing13 of two13 endangered species13 in a hatchery environment Proceedings of the Annual Conference of the Western13 Association of State Game and Fish Commissions 54 252-shy‐259

Tyus H M13 1998 Razorback sucker13 (Xyrauchen texanus) recovery plan13 University13 ofColorado Center for Limnology Boulder13 76 pages

Tyus H M13 and13 S H Severson 1990 Growth13 and13 survival of larval razorback suckers fedfive formulated diets The Progressive Fish Culturist 52197-shy‐200

56

13

Ulibarri M E 2003 Annual report fiscal year 2001 Dexter National Fish Hatchery13 andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 26 pages

Ulibarri M E 2003 Annual report fiscal year 2002 Dexter National Fish Hatchery andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 59 pages

USBR 2006 Lower13 Colorado13 River Multi-shy‐Species Conservation Program final fishaugmentation plan Boulder City 19 pp

USFWS 2002 Razorback sucker (Xyraouchen texanus) recovery goals Amendment andsupplement to the Razorback Sucker Recovery Plan13 US Fish and Wildlife Service13 Region 6 Denver13 Colorado

USFWS 1999 Annual report 1999 Ouray National Fish Hatchery Vernal 25pp

USFWS 2004 Management plan for the big-shy‐river13 fishes of the13 lower13 Colorado13 river basinamendment and supplement to the bonytail humpback chub Coloradopikeminnow and razorback sucker recovery plans

USFWS13 2005 Station13 profile13 of the13 Dexter13 National Fish Hatchery13 and Technology CenterUS Fish and Wildlife13 Service Dexter

Valdez R A P G Mangan R Smith and B Nilson 1982 Upper Colorado River fisheriesinvestigations13 inW H Miller J J Valentine D L Archer H M Tyus R A Valdezand L13 Kaeding13 editors13 Colorado River Fishery13 Project13 Part 2 Field13 investigations13 US Bureau of Reclamation Salt Lake City Utah

WBNFH 2004 Culture methods of the endangered razorback sucker Xyrauchen texanusUS Fish and Wildlife13 Service Willow Beach National Fish Hatchery13 8 pp

Ward D 2008 Effects of disease treatments on growth of razorback sucker ReportSubmitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 Inpartial fulfillment of work task C10 agreement number 06FG30039

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57

Appendices

Appendix 1 Survey Questions Survey of Razorback Sucker Culture in the

Southwestern United States

The enclosed survey is being distributed by the Arizona Game and Fish Department to razorback sucker culture facilities throughout

the Southwestern United States The purpose of this survey is to consolidate information regarding culture of this species so that

appropriate facility improvements can be considered for Bubbling Ponds Hatchery in Arizona Specifically we wish to increase

growth rate and production efficiency at the hatchery Information gathered in this survey will be summarized in a final report to US

Bureau of Reclamation in Boulder City NV and disseminated to all facilities that participate in the survey A workshop to discuss

the findings of this study as well as to share general information concerning razorback sucker culture will be organized by the

Arizona Game and Fish Department at the conclusion of this study and all participants will be invited

Thank you for taking the time to fill out this survey Please contact Mike Childs if you have questions or would like to discuss the

survey

Mike Childs

mchildssedonanet

(928) 639-1346

(928) 634-1279

Facility_____________________________________ Date___________________

Contact Phone _____________________________

ContactPerson_______________________________

Contact Email _______________________________

1 Water quality ranges at this culture facility

Season

Spring (Mar-May) Summer (Jun-Aug) Fall (Sept-Nov) Winter (Dec-Feb)

Temperature (C)

PH

DO (mgL)

PO4 (mgL)

TDS (mgL)

Hardness (mgL)

CaCO3

Pathogens

37

13

Results

Growth in Lined Ponds

Razorback suckers13 that had been13 in13 Pond 8 upper for the13 entire13 year13 grew an13

average of 0263 mmday (789 mmmonth) and razorback suckers that had been in the

pond for 7 months (Oct -shy‐ May) grew13 on13 average of 028 mmday (843 mmmonth) (Figure13

7) These growth13 rates13 did not significantly13 differ Fish density13 in Pond 3 during13 the13

majority of the growth period was13 00032 ndash 00036 fishgallon13 Additionally no13 significant

differences in growth rate were observed between fish smaller than 210 mm TL and fish

larger than 210 mm TL when all recaptured fish were combined

We also measured the growth rate of very large fish in a lined pond On Jan13 2513 201013

156 adult fish with PIT tags were recovered from13 Pond 3 upper13 These fish were13 in the13

pond for 257 days and experienced an average13 growth13 rate13 of 024mmday or 73

mmmonth (Figure13 7)13 This growth13 rate13 is slightly13 lower13 than13 the13 average13 growth13 rate13

observed13 at Bubbling13 Ponds Hatchery in other studies (0275 mmday 825 mmmonth)

but may not be biologically meaningful We would expect larger13 fish to13 have13 reduced

growth rates according to a typical Von Bertalanfy growth model (Bertalanffy 1957) but it

appears that13 over the size range we evaluated (300 -shy‐ 450 mm TL) growth rates have not

slowed significantly compared to that of smaller13 fish grown at Bubbling Ponds13 Hatchery

Growth13 of razorback suckers13 is known13 to13 slow as13 fish reach13 larger13 sizes but it appears13 this13

reduced growth rate may not really start to be biologically meaningful at Bubbling Ponds

Hatchery13 until razorback suckers13 exceed 450 mm TL

Growth in unlined ponds

Growth13 rates13 for the13 fish recaptured13 during13 the Pond 1 lower13 thinning13 (120 days13 in

the pond) was 024 plusmn 003 mmday (729 plusmn 090 mmmonth) (Figure13 8)13 Fish13 that were13 in

the pond for nearly the entire year grew13 an13 average13 of 024 plusmn 001 mmday (726 plusmn 027

mmmonth) These growth rates are surprisingly the lowest measured growth rates for

any part of our study and differ significantly from13 every other measured growth rate

except very large13 fish (Figure13 9)13 Separating13 out13 large fish that13 were in13 the pond for the

entire year makes no difference fish that were added to the pond at TL lt300 mm grew

43

13

Gro

wth

Rat

e (m

md

ay)

020

026

032

0244 plusmn 001 mmday (733 plusmn 028 mmmonth) and and those with TL gt= 300 mm at the

start of the experiment grew 022 plusmn 003 mmday (651 plusmn 101 mmmonth)

Razorback Growth Rates in Lined Ponds

Figure 7 Growth ofrazorback suckers in(mmday plusmn standard error)in Pond 8 upper in 2008-shy‐2009 An ANOVA did notdetect any significantdifferences

7 Months Full Year 300+ mm fish

Effects of sorting on growth

One hundred and seventy five tagged razorback suckers were recovered from13 Pond

8 upper13 on March13 24 2010 (378 days13 of growth)13 These were13 the13 larger sorted13 fish (gt140

mm TL) that came out of Pond13 5 on March13 11 2009 One13 hundred and13 twenty13 two13 tagged13

razorback suckers were also recovered from13 Pond13 7 upper on March13 31 2010 (385 days13 of

growth)13 These were13 the13 smaller sorted13 fish (lt140 mm TL) that came out of Pond13 5 on

March 1113 200913 No significant differences in growth rate (mmday) were observed among

larger fish in Pond 8 and smaller fish in Pond 7 (pgt005 ANOVA) (Figure 10)13 indicating

that13 sorting may have helped to offset the original slower growth trajectory of the smaller

fish Temperatures of Ponds 7 and 8 upper remained similar throughout the year13 (Figure

5)

44

13

13

13

Gro

wth

Rat

e (m

md

ay)

Gro

wth

Rat

e (m

md

ay)

020

026

032

020

026

032

Razorback Growth in an Unlined Pond

Figure 8 Growth of razorbacksuckers (mmday plusmn standard error) in Pond 1 lower (an unlined pond)in 2010-shy‐2011 An ANOVA did notdetect any significant differences

6 Months 12 Months lt 300 mm Fish 300+ mm Fish Growth Growth

Lined vs Earthen Ponds 1 year of growth

Figure 9 Growth of razorbacksuckers (mmday plusmn standard error) in lined and unlined ponds A t-shy‐test13 did not detect a significantdifference

Lined Pond Unlined Pond 1 Yr Growth 1 Yr Growth

45

13

Effect of Sorting G

row

th R

ate

(mm

day

) G

row

th R

ate

(mm

day

)

032

020

026

032

020

026

Smaller Fish Larger Fish

Effect of Ich

Figure 10 Average growthof razorback suckers(mmday plusmn standard error)that were size-shy‐sorted intosmall fish (pond 7) and largefish (pond 8) populations At-shy‐test did not detect asignificant difference

Figure 11 Average growth ofrazorback suckers (mmday plusmnstandard error) after Ich wasremovd from the hatcheryrsquos springand after Ich was again detected inthe pond The growth rate withoutIch is significantly higher than boththe rate after Ich and the ourstudyrsquos average annual growth ratein lined ponds (ANOVA p =00003)

Growth without Ich Growth With Ich Average Annual 4 months 4 months Growth Rate

46

13

Effect of Ich on razorback sucker growth rates

Seventy-shy‐four13 tagged13 razorback suckers13 were13 recovered from13 Pond 8 on September

15 2010 These fish had13 been13 in the pond for 4 months and experienced a growth rate of

032 mmday or 97 mmmonth (Figure13 11)13 This growth13 rate13 is significantly higher (p =

005 two sample t-shy‐test) than the mean growth rate for the same group13 of tagged fish after

Ich detection (022 mmday or 65 mmmonth) and significantly higher than any other

individual growth13 rates13 observed13 to13 date13 at Bubbling13 Ponds Hatchery13 (Figure13 11)13 If this13

growth13 rate13 were13 extended throughout13 the entire13 year13 fish on average from13 Ich-shy‐free13 ponds13

would be 16 mm longer than fish from13 ponds infested with Ich Studies conducted at

Bubbling Ponds hatchery in 2008 (Ward 2008) did not reveal any effects of the treatment

chemicals on razorback sucker growth rates so it13 is likely that13 the parasite outbreaks

themselves are causing reducing growth rates rather than the chemicals used to treat the

parasites13

Conclusions

Our results suggest that under typical hatchery operations (maximizing number of

fish produced)13 the growth13 rate13 of razorback13 suckers13 is relatively13 consistent at Bubbling13

Ponds hatchery13 at 02-shy‐03 mmday (6-shy‐9 mmmonth)13 but is lower than growth13 rates13 at

other13 facilities (02 ndash 18 mmday Ward et al 2007)13 This growth13 rate13 has13 been13 constant in

both lined and unlined ponds and at all fish densities we were able to measure To achieve13

growth13 rates13 substantially higher than this will likely require13 significant changes in rearing

practices that may not be practical in order to reach numerical production13 goals

Temperature is a key variable in fish growth but seasonal growth patterns

described13 above13 (Figure13 5) demonstrate that water temperatures are high enough in

winter to maintain razorback growth Differences in water temperature by season

currently13 do not fluctuate more than 10degC at Bubbling Ponds because of the continuous

supply of water flowing through each pond (approx 225 gallonsmin) These high water

flows appear to keep pond temperatures within the thermal preference13 for razorback

suckers13 (1213 -shy‐ 28 degC Bulkley and Pimentel 1983) throughout the entire year with

temperatures rarely dropping13 below 16deg13 C (Figures 513 6)13

47

13

Fish density is another key variable in fish growth and though the number of fish in

a pond during our study ranged from13 3000 to 700013 fish we13 did not find any13 correlation13

between13 density and growth rate13 This might yield two conclusions First13 razorback

growth13 may be changed equally13 by13 densities13 at the13 hatchery13 (ie13 a density13 of 3000 fish in a

pond is as stressful13 for razorbacks as a density13 of 7000 fish) An alternative is that other

factors13 such as disease outbreaks have13 stronger13 control over fish growth13 than13 density13

Fish density13 would13 have13 to13 be13 experimentally manipulated to test13 this13 and hatchery

operations (producing the maximum13 number of fish) prevented our manipulating density13

in ponds for this13 work The trouble with manipulating density demonstrates the difficulties

associated with changing13 hatchery13 practices experimenting with density would have

prevented BPH from13 meeting13 production13 goals Given that the stocking of smaller

razorbacks has met with very little success perhaps BPH goals could be changed from13

producing 12000 fish at 300+ mm per year to a smaller number of very large fish each

year Growing13 fewer13 larger13 fish could potentially be accomplished in the same time frame

as more smaller fish but a better understanding of how density alters growth rate would

be required to be confident13 of this

The very slow growth13 in the13 earthen13 unlined13 Pond 1 lower13 was very surprising We13

had13 anticipated13 that the13 diversified diet13 cover and13 other13 habitat features13 provided by13

unlined ponds would yield dramatically increased growth rates However these traits were

not enough to offset high fish densities and in fact the unlined pond in our study13 suffered

mortality to bring densities down to that observed normally in lined ponds

Our data13 suggest13 that razorbacks13 sucker13 growth13 rates13 are13 higher in lined13 ponds13

However we13 think the reasons13 for the13 very slow growth we observed13 in the13 unlined13 pond13

in our study13 is instead13 linked13 to13 the13 usage13 of Pond 1 lower13 during13 the13 study13 rather13 than13

intrinsic13 slow growth13 in earthen13 ponds First the pond was at extremely high density for at

least part of the study The volume of Pond 1 lower has not been estimated but hatchery

managers suggest 1500-shy‐2000 fish is an appropriate number of individuals so this pond

was at a very high density for much of the experiment Second dissolved oxygen is often

very low in the13 large13 earthen13 ponds during the heat of summer much lower than that of

lined ponds This will both limit the number of fish that can survive in the pond and almost

certainly13 increases stress13 of these13 fish potentially13 reducing growth13 The DO crashes also13

48

13

limit the amount of feed hatchery managers can give fish in these ponds sometimes for

days or weeks at a time which further reduces growth during warm13 weather

Our data13 suggests that13 growth rates at the Bubbling13 Ponds Fish Hatchery are likely

as high as possible given13 the pond densities required to meet production goals and the Ich-shy‐

infested water that feeds the facility Sorting practices are successful in helping as many

fish as possible reach stocking length as fast as possible Unlined ponds may be able to

grow13 large13 fish at low13 densities13 but whatever factors allow13 for that13 growth are not13 able to

overcome high fish density The removal of invasive13 fis that act as13 a host for the13 parasite13

Ich fish from13 the Bubbling13 Ponds spring13 allowed the highest13 growth rate at 032 mmday13

(96 mmmonth) but that growth rate decreased again as Ich re-shy‐infested13 the13 hatchery13

Consistently13 achieving13 growth13 rates13 as high or substantially13 higher than13 this13 will likely13

require13 significant changes in rearing practices that may not be practical in order to13 reach13

numerical production13 goals

Two major changes that might result in higher growth rates are substantially

reducing fish density and modifying the way spring water is delivered to the facility (via

either repeated chemical treatments or enclosed concrete water diversions) to eliminate

Ich from13 the hatchery source water Other potential changes not address by our work

include13 flow-shy‐training razorbacks much previous literature including MSCP-shy‐funded13 work

on razorback suckers13 suggests13 that fish growing13 in flowing water will grow13 faster than fish

in still water (Jorgensen and Jobling 1994) Furthermore there are a wide variety of

potential benefits associated with growing13 fish13 in flowing13 water in addition13 to increased

growth13 rates13 (Davidson13 199713 Castro13 et al13 2011) Another option13 for increasing13 growth13

rates13 include13 changing to13 intensive13 culture13 in large circular13 tanks

Finally given that the stocking of smaller razorbacks has met with very little

success13 perhaps13 BPH13 goals13 could13 be13 changed from13 producing 12000 fish at 300+ mm per

year to a smaller number of very large fish each year Growing fewer larger fish could

potentially be accomplished in the same time frame as more smaller fish but a better

understanding13 of how density13 alters growth13 rate13 would13 be13 required to13 be13 confident of this

49

13

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower13 Colorado13 River Multi-shy‐Species13

Conservation Program13 (LCRMSCP) under Work Task C10 We13 thank Ty Wolters13 Tom13

Burke13 and Eric13 Volkman for their support of this research and Frank Agygos and Dave

Billingsly13 of the Bubbling13 Ponds Fish Hatchery13 for their willingness to participate in13 this

research13 and13 for their technical assistance We also thank the LCRMSCP fish group from13

Boulder City13 NV for their assistance with harvesting13 ponds and tagging13 fish13

50

13

Literature13 CitedAnders P J 1998 Conservation aquaculture and endangered species can objective science13

prevail13 over risk13 anxiety Fisheries 23(11) 28-shy‐31

Anderson R O and R M Nuemann 1996 Length weight and associated structural indicesPages 447 ndash 482 in B R Murphy13 and D13 W Willis13 editors13 Fisheries techniques13 2ndedtion American Fisheries13 Society13 Bethesda13 Maryland

Bain M B J T Finn and H E Brooks 1988 Streamflow regulation and fish communitystructure13 Ecology13 69382-shy‐392

Bays J H Zarbock R Whitman and T Murphy 2005 Conceptual design and managementof native13 fish refugia on the13 lower13 Colorado13 River In13 CL Spring13 and13 S Leoneditors Proceedings of two symposia Restoring native fish to the lower ColoradoRiver13 interactions13 of native and non-shy‐native13 fishes 13ndash1413 July13 1999 Las13 Vegas13 Nevada13 Restoring13 natural function within a modified riverine environment thelower Colorado River13 8ndash913 July13 1998 U S Fish and13 Wildlife13 Service Southwestern13 Region Albuquerque New Mexico Pages 167-shy‐177

Bertalanffy L Von 1957 Quantitative laws in metabolism13 and growth13 Q Rev Biology 32217 ndash 231

Bingham T B Scheer and C McAda 2003 Propagation facilities in Grand Valley (24 RoadHatchery Horsethief13 Ponds and13 grow-shy‐out ponds) for captive13 rearing13 ofendangered13 fishes for the13 upper13 Colorado13 River basin13 Colorado River RecoveryProgram FY2003 annual project report13 US Fish and13 Wildlife13 Service GrandJunction13 4pp

Birchell G J and K Christopherson 2004 Survival growth and recruitment of larval andjuvenile razorback13 sucker (Xyrauchen texanus) introduced13 into13 floodplain13 depressions13 of the13 Green River Utah13 Final report13 Upper13 Colorado13 RiverEndangered Fish Recovery Program13 Project No C-shy‐6RZ Publication Number 04-shy‐1513 Utah13 Division of Wildlife13 Resources Salt Lake13 City13 Utah13 67 pages

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Brett J R 1979 Environmental Factors and growth pages 599-shy‐67513 InW S Hoar13 D13 J13 Randall and J R Brett (eds) Fish Physiology Volume 8 Bioenergetics and GrowthAcademic Press New York

Brooks J E 1986 Annual reintroduction and monitoring report for razorback suckerXyrauchen texanus in the Gila River Basin Arizona 1985 US Fish and WildlifeService13 Offices of Endangered13 Species and Fishery13 Resources Albuquerque 23 pp

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13

Brunson13 R E and K D13 Christopherson13 200513 Larval13 razorback13 sucker and bonytailsurvival and13 growth13 in the13 presence13 of nonnative13 fish in the13 Baeser13 floodplainwetland of the middle Green River Final report prepared for Upper13 Colorado RiverBasin Endangered Fish Recovery Program Project No C-shy‐6-shy‐rz-shy‐bt Publication13 No 05-shy‐26 Utah13 Division of Wildlife13 Resources13 Vernal13 32 pp

Bulkley R V and R Pimentel 1983 Temperature preference and avoidance by adultrazorback suckers Transactions of the American Fisheries Society 112601-shy‐607

Burke13 T13 199513 Rearing13 wild razorback13 sucker larvae in13 lake-shy‐side13 backwaters13 LakeMohave ArizonaNevada Proceedings of the Desert Fishes Council 2635

Busacker G P I R Adelman and E M Goolish13 199013 Growth13 Pages 363 ndash 387 in C BSchreck and p B Moyle editors Methods for fish biology American FisheriesSociety Bethesda Maryland

Castro V B Grisdale-shy‐Helland S J Helland T Kristensen S M Jorgensen J Helgrud13 GClaireaux A P Farrell A Krasnov and H Takle 2011 Aerobic training stimulatesgrowth and promotes disease resistance in Atlantic salmon (Salmo salar)Comparative Biochemistry and Physiology -shy‐ Part A Molecular amp IntegrativePhysiology13 160(2) 278-shy‐290

Czapla T E 2002 Facilities plan for the production of endangered fishes to meet statestocking13 plans13 as13 part of the13 Upper13 Colorado13 River Endangered13 Fish RecoveryProgram Upper Colorado River Basin Recovery Implementation Program US Fishand Wildlife Service13 Denver13 9 pp

Davidson W 1997 The effects13 of exercise13 training on teleost fish a review of recentliterature Comput Biochem Physiol 117A67ndash75

Figiel Jr C R 2005 Annual report fiscal year 2004 Willow Beach National13 Fish HatcheryUS Fish and Wildlife13 Service Willow Beach 17 pp

Figiel Jr C R M E Ulibarri G Carmichael J Seals and J N Hanson 2005 Intensive13 fish13 culture of warmwater native fishes at a coldwater fish hatchery Pages 164-shy‐16613 inProceedings of two symposia restoring native fish to the lower Colorado13 River13 interaction13 of native13 and13 non-shy‐native13 fishes July13 13-shy‐1413 1999 Las Vegas Nevada USFish and Wildlife Service Southwest Region Albuquerque New Mexico

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Gustafson W and Q Bradwisch 2000 Wahweap operation and maintenance -shy‐-shy‐ UtahColorado River Recovery Program FY 2000 annual project report Project No 29cUtah13 Division of Wildlife13 Resources Page AZ 3pp

52

13

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Kaeding L R and D B Osmundson 198913 Colorado13 Squawfish13 and13 razorback sucker grow-shy‐out pond studies as part of conservation measures for the green mountain andRuedi reservoir water sales Final report for agreement number 6-shy‐AA-shy‐60-shy‐00150

Koebele13 B P13 198513 Growth and the size hierarchy effect an experimental assessment ofthree proposed mechanisms activity differences disproportional food acquisition13 pysiological stress Environmental Biology of Fishes 12 181-shy‐188

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Marsh13 P13 C13 1987a13 Digestive tract13 contents13 of adult razorback suckers13 in Lake13 MohaveArizona-shy‐Nevada Transactions of the American Fisheries Society 116117-shy‐119

Marsh P C 1987b Native fishes at Buenos Aires National Wildlife Refuge and ArizonaState University Research Park Arizona opportunities for management researchand public13 education13 on13 endangered species13 Proceedings of the Desert13 FishesCouncil 1967-shy‐78

Marsh P C 1994 Rearing native Colorado River fishes in golf course ponds Arizona StateUniversity Tempe 22 + pages

Marsh13 P13 C13 200013 Fish population13 status and evaluation13 in13 the Cibola13 High Levee PondFinal report agreement number 99-shy‐FG-shy‐30-shy‐00051 US Bureau of ReclamationBoulder City13 Nevada13 20 pages

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53

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Marsh P C B R Kesner and C A Pacey 2005 Repatriation as s management strategy13 to13 conserve a critically13 imperiled fish species North American Journal of FisheriesManagement 25 547-shy‐556

Marsh P C and C A Pacey 2005 Immiscibility of native and non-shy‐native13 fishes Pages 59-shy‐63 inMJ13 Brouder13 CL13 Springer13 and CS13 Leon13 editors13 Proceedings of two13 symposia Restoring native fish to the lower Colorado River interactions of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 NV and13 Restoring natural13 function within a modified riverine environment the lower Colorado River13 July13 8-shy‐913 1998 Las Vegas NV US Fish and13 Wildlife13 Service Southwest Region AlbuquerqueNew Mexico

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Minckley13 W L13 199113 Native fished of the Grand Canyon13 region an obituary13 Pages 124-shy‐177 in Colorado River ecology and dam13 management National Academy PressWashington13 DC

Minckley13 C13 O and M LaBarbara13 199913 Report13 on13 native fish grow-shy‐out facilities13 at Cibolaand Imperial National Wildlife Refuges 1993-shy‐199513 US Fish and13 Wildlife Service13 Parker Fishery Resources Office Parker Arizona

Modde13 T13 199613 Juvenile razorback sucker (Xyrauchen texanus) in a managed wetlandadjacent13 to the Green13 River13 Great13 Basin13 Naturalist13 56375-shy‐376

Modde T KP Burnham and E J Wick 1996 Population status of the razorback sucker13 inthe middle Green River (USA) Conservation13 biology 10 110-shy‐119

Modde13 T13 and G13 B Haines13 200513 Survival13 and growth of stocked razorback13 sucker andbonytail in multiple floodplain wetlands of the middle Green River under resetconditions13 Final report prepared for Upper Colorado13 River13 Basin RecoveryImplimentation Program US Fish and Wildlife Service Vernal 66 pp

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Modde T Z H Bowen and D C Kitcheyan 2005 Spatial and temporal use of a spawning13 site in the middle Green River by wild hatchery-shy‐reared13 razorback suckers13 Transactions of the American Fisheries Society 134937-shy‐944

Mueller13 G13 199213 The native fish work13 group13 -shy‐ a multiagency endeavor to improve thestatus of the razorback sucker in Lake Mohave AZ-shy‐NV13 Proceedings of the DesertFishes Council 2369

Mueller G 1995 A program13 for maintaining the razorback sucker in Lake MohaveAmerican Fisheries Society Symposium 15127-shy‐135

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Mueller G and E Wick 1998 Testing of golf course ponds at Page Arizona for suitability13 as grow-shy‐out facility for razorback sucker using surplus fish from13 Ouray NationalFish Hatchery National Park Service US Fish and13 Wildlife13 Service and UtahDivision of Wildlife13 Resources 28 pages

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Mueller13 G13 J13 Carpenter13 and P13 C13 Marsh13 200413 Cibola13 High Levee Pond annual report 2004US Geological Survey Fort Collins13 Science Center13 Colorado13 and Arizona StateUniversity Tempe 23 pages

Nesler T P K Christopherson J M Hudson C W McAda F Pfeifer and T E Czapla 2003An integrated stocking plan for razorback sucker bonytail and Colorado13 pikeminnow for the Upper Colorado River Endangered Fish Recovery ProgramAddendum13 to State Stocking Plans Upper Colorado River Basin Recovery13 Implementation Program 12 pp

Papoulias13 D and W13 L Minckley13 1992 Effects13 of foo availability13 on survival and growth13 of larval razorback suckers13 in ponds Transactions of the American Fisheries Society121340-shy‐355

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Rabago-shy‐Castro J L Sanchez13 J G Perez-shy‐Castaneda R and13 Gonzalez-shy‐Gonzlez A 2006Effects of the prophylactic use of Romet-shy‐3013 and13 copper13 sulfate13 on growth13 condition13 and feeding13 indicies in13 channel13 catfish (Ictalurus punctatus) Aquaculture 253 343-shy‐349

Reinitz GL L E Orme and F N Hitzel 1979 Variations of body compositio and growth13 among strains of rainbow trout Transactions of the American Fisheries Society 108204-shy‐207

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Schnoor K D and J Logan 2002 Operation and maintenance of JW Mumma nativeaquatic13 species restoration facility Colorado Colorado River Recovery Program FY2002 annual project report13 Project No 29d Colorado13 Division of Wildlife Alamosa3pp

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57

Appendices

Appendix 1 Survey Questions Survey of Razorback Sucker Culture in the

Southwestern United States

The enclosed survey is being distributed by the Arizona Game and Fish Department to razorback sucker culture facilities throughout

the Southwestern United States The purpose of this survey is to consolidate information regarding culture of this species so that

appropriate facility improvements can be considered for Bubbling Ponds Hatchery in Arizona Specifically we wish to increase

growth rate and production efficiency at the hatchery Information gathered in this survey will be summarized in a final report to US

Bureau of Reclamation in Boulder City NV and disseminated to all facilities that participate in the survey A workshop to discuss

the findings of this study as well as to share general information concerning razorback sucker culture will be organized by the

Arizona Game and Fish Department at the conclusion of this study and all participants will be invited

Thank you for taking the time to fill out this survey Please contact Mike Childs if you have questions or would like to discuss the

survey

Mike Childs

mchildssedonanet

(928) 639-1346

(928) 634-1279

Facility_____________________________________ Date___________________

Contact Phone _____________________________

ContactPerson_______________________________

Contact Email _______________________________

1 Water quality ranges at this culture facility

Season

Spring (Mar-May) Summer (Jun-Aug) Fall (Sept-Nov) Winter (Dec-Feb)

Temperature (C)

PH

DO (mgL)

PO4 (mgL)

TDS (mgL)

Hardness (mgL)

CaCO3

Pathogens

37

13

Gro

wth

Rat

e (m

md

ay)

020

026

032

0244 plusmn 001 mmday (733 plusmn 028 mmmonth) and and those with TL gt= 300 mm at the

start of the experiment grew 022 plusmn 003 mmday (651 plusmn 101 mmmonth)

Razorback Growth Rates in Lined Ponds

Figure 7 Growth ofrazorback suckers in(mmday plusmn standard error)in Pond 8 upper in 2008-shy‐2009 An ANOVA did notdetect any significantdifferences

7 Months Full Year 300+ mm fish

Effects of sorting on growth

One hundred and seventy five tagged razorback suckers were recovered from13 Pond

8 upper13 on March13 24 2010 (378 days13 of growth)13 These were13 the13 larger sorted13 fish (gt140

mm TL) that came out of Pond13 5 on March13 11 2009 One13 hundred and13 twenty13 two13 tagged13

razorback suckers were also recovered from13 Pond13 7 upper on March13 31 2010 (385 days13 of

growth)13 These were13 the13 smaller sorted13 fish (lt140 mm TL) that came out of Pond13 5 on

March 1113 200913 No significant differences in growth rate (mmday) were observed among

larger fish in Pond 8 and smaller fish in Pond 7 (pgt005 ANOVA) (Figure 10)13 indicating

that13 sorting may have helped to offset the original slower growth trajectory of the smaller

fish Temperatures of Ponds 7 and 8 upper remained similar throughout the year13 (Figure

5)

44

13

13

13

Gro

wth

Rat

e (m

md

ay)

Gro

wth

Rat

e (m

md

ay)

020

026

032

020

026

032

Razorback Growth in an Unlined Pond

Figure 8 Growth of razorbacksuckers (mmday plusmn standard error) in Pond 1 lower (an unlined pond)in 2010-shy‐2011 An ANOVA did notdetect any significant differences

6 Months 12 Months lt 300 mm Fish 300+ mm Fish Growth Growth

Lined vs Earthen Ponds 1 year of growth

Figure 9 Growth of razorbacksuckers (mmday plusmn standard error) in lined and unlined ponds A t-shy‐test13 did not detect a significantdifference

Lined Pond Unlined Pond 1 Yr Growth 1 Yr Growth

45

13

Effect of Sorting G

row

th R

ate

(mm

day

) G

row

th R

ate

(mm

day

)

032

020

026

032

020

026

Smaller Fish Larger Fish

Effect of Ich

Figure 10 Average growthof razorback suckers(mmday plusmn standard error)that were size-shy‐sorted intosmall fish (pond 7) and largefish (pond 8) populations At-shy‐test did not detect asignificant difference

Figure 11 Average growth ofrazorback suckers (mmday plusmnstandard error) after Ich wasremovd from the hatcheryrsquos springand after Ich was again detected inthe pond The growth rate withoutIch is significantly higher than boththe rate after Ich and the ourstudyrsquos average annual growth ratein lined ponds (ANOVA p =00003)

Growth without Ich Growth With Ich Average Annual 4 months 4 months Growth Rate

46

13

Effect of Ich on razorback sucker growth rates

Seventy-shy‐four13 tagged13 razorback suckers13 were13 recovered from13 Pond 8 on September

15 2010 These fish had13 been13 in the pond for 4 months and experienced a growth rate of

032 mmday or 97 mmmonth (Figure13 11)13 This growth13 rate13 is significantly higher (p =

005 two sample t-shy‐test) than the mean growth rate for the same group13 of tagged fish after

Ich detection (022 mmday or 65 mmmonth) and significantly higher than any other

individual growth13 rates13 observed13 to13 date13 at Bubbling13 Ponds Hatchery13 (Figure13 11)13 If this13

growth13 rate13 were13 extended throughout13 the entire13 year13 fish on average from13 Ich-shy‐free13 ponds13

would be 16 mm longer than fish from13 ponds infested with Ich Studies conducted at

Bubbling Ponds hatchery in 2008 (Ward 2008) did not reveal any effects of the treatment

chemicals on razorback sucker growth rates so it13 is likely that13 the parasite outbreaks

themselves are causing reducing growth rates rather than the chemicals used to treat the

parasites13

Conclusions

Our results suggest that under typical hatchery operations (maximizing number of

fish produced)13 the growth13 rate13 of razorback13 suckers13 is relatively13 consistent at Bubbling13

Ponds hatchery13 at 02-shy‐03 mmday (6-shy‐9 mmmonth)13 but is lower than growth13 rates13 at

other13 facilities (02 ndash 18 mmday Ward et al 2007)13 This growth13 rate13 has13 been13 constant in

both lined and unlined ponds and at all fish densities we were able to measure To achieve13

growth13 rates13 substantially higher than this will likely require13 significant changes in rearing

practices that may not be practical in order to reach numerical production13 goals

Temperature is a key variable in fish growth but seasonal growth patterns

described13 above13 (Figure13 5) demonstrate that water temperatures are high enough in

winter to maintain razorback growth Differences in water temperature by season

currently13 do not fluctuate more than 10degC at Bubbling Ponds because of the continuous

supply of water flowing through each pond (approx 225 gallonsmin) These high water

flows appear to keep pond temperatures within the thermal preference13 for razorback

suckers13 (1213 -shy‐ 28 degC Bulkley and Pimentel 1983) throughout the entire year with

temperatures rarely dropping13 below 16deg13 C (Figures 513 6)13

47

13

Fish density is another key variable in fish growth and though the number of fish in

a pond during our study ranged from13 3000 to 700013 fish we13 did not find any13 correlation13

between13 density and growth rate13 This might yield two conclusions First13 razorback

growth13 may be changed equally13 by13 densities13 at the13 hatchery13 (ie13 a density13 of 3000 fish in a

pond is as stressful13 for razorbacks as a density13 of 7000 fish) An alternative is that other

factors13 such as disease outbreaks have13 stronger13 control over fish growth13 than13 density13

Fish density13 would13 have13 to13 be13 experimentally manipulated to test13 this13 and hatchery

operations (producing the maximum13 number of fish) prevented our manipulating density13

in ponds for this13 work The trouble with manipulating density demonstrates the difficulties

associated with changing13 hatchery13 practices experimenting with density would have

prevented BPH from13 meeting13 production13 goals Given that the stocking of smaller

razorbacks has met with very little success perhaps BPH goals could be changed from13

producing 12000 fish at 300+ mm per year to a smaller number of very large fish each

year Growing13 fewer13 larger13 fish could potentially be accomplished in the same time frame

as more smaller fish but a better understanding of how density alters growth rate would

be required to be confident13 of this

The very slow growth13 in the13 earthen13 unlined13 Pond 1 lower13 was very surprising We13

had13 anticipated13 that the13 diversified diet13 cover and13 other13 habitat features13 provided by13

unlined ponds would yield dramatically increased growth rates However these traits were

not enough to offset high fish densities and in fact the unlined pond in our study13 suffered

mortality to bring densities down to that observed normally in lined ponds

Our data13 suggest13 that razorbacks13 sucker13 growth13 rates13 are13 higher in lined13 ponds13

However we13 think the reasons13 for the13 very slow growth we observed13 in the13 unlined13 pond13

in our study13 is instead13 linked13 to13 the13 usage13 of Pond 1 lower13 during13 the13 study13 rather13 than13

intrinsic13 slow growth13 in earthen13 ponds First the pond was at extremely high density for at

least part of the study The volume of Pond 1 lower has not been estimated but hatchery

managers suggest 1500-shy‐2000 fish is an appropriate number of individuals so this pond

was at a very high density for much of the experiment Second dissolved oxygen is often

very low in the13 large13 earthen13 ponds during the heat of summer much lower than that of

lined ponds This will both limit the number of fish that can survive in the pond and almost

certainly13 increases stress13 of these13 fish potentially13 reducing growth13 The DO crashes also13

48

13

limit the amount of feed hatchery managers can give fish in these ponds sometimes for

days or weeks at a time which further reduces growth during warm13 weather

Our data13 suggests that13 growth rates at the Bubbling13 Ponds Fish Hatchery are likely

as high as possible given13 the pond densities required to meet production goals and the Ich-shy‐

infested water that feeds the facility Sorting practices are successful in helping as many

fish as possible reach stocking length as fast as possible Unlined ponds may be able to

grow13 large13 fish at low13 densities13 but whatever factors allow13 for that13 growth are not13 able to

overcome high fish density The removal of invasive13 fis that act as13 a host for the13 parasite13

Ich fish from13 the Bubbling13 Ponds spring13 allowed the highest13 growth rate at 032 mmday13

(96 mmmonth) but that growth rate decreased again as Ich re-shy‐infested13 the13 hatchery13

Consistently13 achieving13 growth13 rates13 as high or substantially13 higher than13 this13 will likely13

require13 significant changes in rearing practices that may not be practical in order to13 reach13

numerical production13 goals

Two major changes that might result in higher growth rates are substantially

reducing fish density and modifying the way spring water is delivered to the facility (via

either repeated chemical treatments or enclosed concrete water diversions) to eliminate

Ich from13 the hatchery source water Other potential changes not address by our work

include13 flow-shy‐training razorbacks much previous literature including MSCP-shy‐funded13 work

on razorback suckers13 suggests13 that fish growing13 in flowing water will grow13 faster than fish

in still water (Jorgensen and Jobling 1994) Furthermore there are a wide variety of

potential benefits associated with growing13 fish13 in flowing13 water in addition13 to increased

growth13 rates13 (Davidson13 199713 Castro13 et al13 2011) Another option13 for increasing13 growth13

rates13 include13 changing to13 intensive13 culture13 in large circular13 tanks

Finally given that the stocking of smaller razorbacks has met with very little

success13 perhaps13 BPH13 goals13 could13 be13 changed from13 producing 12000 fish at 300+ mm per

year to a smaller number of very large fish each year Growing fewer larger fish could

potentially be accomplished in the same time frame as more smaller fish but a better

understanding13 of how density13 alters growth13 rate13 would13 be13 required to13 be13 confident of this

49

13

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower13 Colorado13 River Multi-shy‐Species13

Conservation Program13 (LCRMSCP) under Work Task C10 We13 thank Ty Wolters13 Tom13

Burke13 and Eric13 Volkman for their support of this research and Frank Agygos and Dave

Billingsly13 of the Bubbling13 Ponds Fish Hatchery13 for their willingness to participate in13 this

research13 and13 for their technical assistance We also thank the LCRMSCP fish group from13

Boulder City13 NV for their assistance with harvesting13 ponds and tagging13 fish13

50

13

Literature13 CitedAnders P J 1998 Conservation aquaculture and endangered species can objective science13

prevail13 over risk13 anxiety Fisheries 23(11) 28-shy‐31

Anderson R O and R M Nuemann 1996 Length weight and associated structural indicesPages 447 ndash 482 in B R Murphy13 and D13 W Willis13 editors13 Fisheries techniques13 2ndedtion American Fisheries13 Society13 Bethesda13 Maryland

Bain M B J T Finn and H E Brooks 1988 Streamflow regulation and fish communitystructure13 Ecology13 69382-shy‐392

Bays J H Zarbock R Whitman and T Murphy 2005 Conceptual design and managementof native13 fish refugia on the13 lower13 Colorado13 River In13 CL Spring13 and13 S Leoneditors Proceedings of two symposia Restoring native fish to the lower ColoradoRiver13 interactions13 of native and non-shy‐native13 fishes 13ndash1413 July13 1999 Las13 Vegas13 Nevada13 Restoring13 natural function within a modified riverine environment thelower Colorado River13 8ndash913 July13 1998 U S Fish and13 Wildlife13 Service Southwestern13 Region Albuquerque New Mexico Pages 167-shy‐177

Bertalanffy L Von 1957 Quantitative laws in metabolism13 and growth13 Q Rev Biology 32217 ndash 231

Bingham T B Scheer and C McAda 2003 Propagation facilities in Grand Valley (24 RoadHatchery Horsethief13 Ponds and13 grow-shy‐out ponds) for captive13 rearing13 ofendangered13 fishes for the13 upper13 Colorado13 River basin13 Colorado River RecoveryProgram FY2003 annual project report13 US Fish and13 Wildlife13 Service GrandJunction13 4pp

Birchell G J and K Christopherson 2004 Survival growth and recruitment of larval andjuvenile razorback13 sucker (Xyrauchen texanus) introduced13 into13 floodplain13 depressions13 of the13 Green River Utah13 Final report13 Upper13 Colorado13 RiverEndangered Fish Recovery Program13 Project No C-shy‐6RZ Publication Number 04-shy‐1513 Utah13 Division of Wildlife13 Resources Salt Lake13 City13 Utah13 67 pages

Brannon E L 1993 The perpetual oversight of hatchery programs Fishery Research 1819-shy‐27

Brett J R 1979 Environmental Factors and growth pages 599-shy‐67513 InW S Hoar13 D13 J13 Randall and J R Brett (eds) Fish Physiology Volume 8 Bioenergetics and GrowthAcademic Press New York

Brooks J E 1986 Annual reintroduction and monitoring report for razorback suckerXyrauchen texanus in the Gila River Basin Arizona 1985 US Fish and WildlifeService13 Offices of Endangered13 Species and Fishery13 Resources Albuquerque 23 pp

51

13

Brunson13 R E and K D13 Christopherson13 200513 Larval13 razorback13 sucker and bonytailsurvival and13 growth13 in the13 presence13 of nonnative13 fish in the13 Baeser13 floodplainwetland of the middle Green River Final report prepared for Upper13 Colorado RiverBasin Endangered Fish Recovery Program Project No C-shy‐6-shy‐rz-shy‐bt Publication13 No 05-shy‐26 Utah13 Division of Wildlife13 Resources13 Vernal13 32 pp

Bulkley R V and R Pimentel 1983 Temperature preference and avoidance by adultrazorback suckers Transactions of the American Fisheries Society 112601-shy‐607

Burke13 T13 199513 Rearing13 wild razorback13 sucker larvae in13 lake-shy‐side13 backwaters13 LakeMohave ArizonaNevada Proceedings of the Desert Fishes Council 2635

Busacker G P I R Adelman and E M Goolish13 199013 Growth13 Pages 363 ndash 387 in C BSchreck and p B Moyle editors Methods for fish biology American FisheriesSociety Bethesda Maryland

Castro V B Grisdale-shy‐Helland S J Helland T Kristensen S M Jorgensen J Helgrud13 GClaireaux A P Farrell A Krasnov and H Takle 2011 Aerobic training stimulatesgrowth and promotes disease resistance in Atlantic salmon (Salmo salar)Comparative Biochemistry and Physiology -shy‐ Part A Molecular amp IntegrativePhysiology13 160(2) 278-shy‐290

Czapla T E 2002 Facilities plan for the production of endangered fishes to meet statestocking13 plans13 as13 part of the13 Upper13 Colorado13 River Endangered13 Fish RecoveryProgram Upper Colorado River Basin Recovery Implementation Program US Fishand Wildlife Service13 Denver13 9 pp

Davidson W 1997 The effects13 of exercise13 training on teleost fish a review of recentliterature Comput Biochem Physiol 117A67ndash75

Figiel Jr C R 2005 Annual report fiscal year 2004 Willow Beach National13 Fish HatcheryUS Fish and Wildlife13 Service Willow Beach 17 pp

Figiel Jr C R M E Ulibarri G Carmichael J Seals and J N Hanson 2005 Intensive13 fish13 culture of warmwater native fishes at a coldwater fish hatchery Pages 164-shy‐16613 inProceedings of two symposia restoring native fish to the lower Colorado13 River13 interaction13 of native13 and13 non-shy‐native13 fishes July13 13-shy‐1413 1999 Las Vegas Nevada USFish and Wildlife Service Southwest Region Albuquerque New Mexico

Gerking13 S D 1978 Ecology of freshwater fish13 production13 Halstead Press13 New13 York

Gustafson W and Q Bradwisch 2000 Wahweap operation and maintenance -shy‐-shy‐ UtahColorado River Recovery Program FY 2000 annual project report Project No 29cUtah13 Division of Wildlife13 Resources Page AZ 3pp

52

13

Hamman R L 1985 Induced spawning of hatchery-shy‐reared13 razorback sucker ProgressivFish Culturist 47(3) 187-shy‐189

Hanson J N 1996 Annual report fiscal year 1996 Willow Beach National Fish HatcheryUS Fish and Wildlife Service13 Willow Beach 9pp

Irving D S Seversen and M Montagne 2004 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2004 annual project13 report Report No 29b US Fish and13 Wildlife13 Service Vernal 3pp

Jorgensen E H and13 M Jobling 1994 Feeding and13 growth13 of exercised13 and13 unexercised13 juvenile Atlantic salmon in freshwater and performance after transfer to seawaterAquaculture International 2 154-shy‐164

Kaeding L R and D B Osmundson 198913 Colorado13 Squawfish13 and13 razorback sucker grow-shy‐out pond studies as part of conservation measures for the green mountain andRuedi reservoir water sales Final report for agreement number 6-shy‐AA-shy‐60-shy‐00150

Koebele13 B P13 198513 Growth and the size hierarchy effect an experimental assessment ofthree proposed mechanisms activity differences disproportional food acquisition13 pysiological stress Environmental Biology of Fishes 12 181-shy‐188

Kretschmann A E and L L Leslie 2006 Razorback sucker (Xyrauchen texanus) status13 reproduction and recruitment in Senator Wash Reservoir CA Final Report13 to USBurea of Reclamation Cooperative Agreement No 00-shy‐FG-shy‐34-shy‐ 0009 p 32 ArizonaGame and Fish Department Phoenix

Marsh13 P13 C13 1987a13 Digestive tract13 contents13 of adult razorback suckers13 in Lake13 MohaveArizona-shy‐Nevada Transactions of the American Fisheries Society 116117-shy‐119

Marsh P C 1987b Native fishes at Buenos Aires National Wildlife Refuge and ArizonaState University Research Park Arizona opportunities for management researchand public13 education13 on13 endangered species13 Proceedings of the Desert13 FishesCouncil 1967-shy‐78

Marsh P C 1994 Rearing native Colorado River fishes in golf course ponds Arizona StateUniversity Tempe 22 + pages

Marsh13 P13 C13 200013 Fish population13 status and evaluation13 in13 the Cibola13 High Levee PondFinal report agreement number 99-shy‐FG-shy‐30-shy‐00051 US Bureau of ReclamationBoulder City13 Nevada13 20 pages

Marsh P C and C A Pacey 1998 Growth of wild adult razorback suckers13 in Lake13 Mohave13 Arizona-shy‐Nevada13 Final report13 US Bureau of Reclamation Boulder City Nevada 25pages + appendices

53

13

Marsh P C B R Kesner and C A Pacey 2005 Repatriation as s management strategy13 to13 conserve a critically13 imperiled fish species North American Journal of FisheriesManagement 25 547-shy‐556

Marsh P C and C A Pacey 2005 Immiscibility of native and non-shy‐native13 fishes Pages 59-shy‐63 inMJ13 Brouder13 CL13 Springer13 and CS13 Leon13 editors13 Proceedings of two13 symposia Restoring native fish to the lower Colorado River interactions of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 NV and13 Restoring natural13 function within a modified riverine environment the lower Colorado River13 July13 8-shy‐913 1998 Las Vegas NV US Fish and13 Wildlife13 Service Southwest Region AlbuquerqueNew Mexico

Marsh13 P13 C13 and J13 E Brooks13 198913 Predation13 by ictalurid catfishes as a deterrent13 toreestablishment of hatchery-shy‐reared13 razorback sucker The Southwestern Naturalist34188-shy‐195

Matthews R A 2005 Ichthyopthirus multifiliis Fouquet and Ichthyopthirosis infreshwater13 teleosts13 Pages13 159-shy‐218 in Advances in Parasitology volume 59 J RBaker R Muller D Rollinson (eds) Academic Press

McCarthy13 M S and W L Minckley 1987 Age estimation for razorback sucker (PiscesCatostomidae) from13 Lake Mohave Arizona and Nevada Journal of the Arizona-shy‐Nevada Academy of Science 2187-shy‐97

Minckley13 W L13 198313 Status of the razorback13 sucker13 Xyrauchen texanus (Abbot)13 in13 thelower Colorado River basin13 The Southwestern13 Naturalist13 28(2) 165-shy‐187

Minckley13 W L13 199113 Native fished of the Grand Canyon13 region an obituary13 Pages 124-shy‐177 in Colorado River ecology and dam13 management National Academy PressWashington13 DC

Minckley13 C13 O and M LaBarbara13 199913 Report13 on13 native fish grow-shy‐out facilities13 at Cibolaand Imperial National Wildlife Refuges 1993-shy‐199513 US Fish and13 Wildlife Service13 Parker Fishery Resources Office Parker Arizona

Modde13 T13 199613 Juvenile razorback sucker (Xyrauchen texanus) in a managed wetlandadjacent13 to the Green13 River13 Great13 Basin13 Naturalist13 56375-shy‐376

Modde T KP Burnham and E J Wick 1996 Population status of the razorback sucker13 inthe middle Green River (USA) Conservation13 biology 10 110-shy‐119

Modde13 T13 and G13 B Haines13 200513 Survival13 and growth of stocked razorback13 sucker andbonytail in multiple floodplain wetlands of the middle Green River under resetconditions13 Final report prepared for Upper Colorado13 River13 Basin RecoveryImplimentation Program US Fish and Wildlife Service Vernal 66 pp

54

13

Modde T Z H Bowen and D C Kitcheyan 2005 Spatial and temporal use of a spawning13 site in the middle Green River by wild hatchery-shy‐reared13 razorback suckers13 Transactions of the American Fisheries Society 134937-shy‐944

Mueller13 G13 199213 The native fish work13 group13 -shy‐ a multiagency endeavor to improve thestatus of the razorback sucker in Lake Mohave AZ-shy‐NV13 Proceedings of the DesertFishes Council 2369

Mueller G 1995 A program13 for maintaining the razorback sucker in Lake MohaveAmerican Fisheries Society Symposium 15127-shy‐135

Mueller13 G13 200613 Ecology of the bonytail13 and razorback13 sucker and the role of offchannelhabitats13 in their13 recovery Scientific13 investigations13 report 2006-shy‐5065 US GeologicalSurvey13 Denver

Mueller G and E Wick 1998 Testing of golf course ponds at Page Arizona for suitability13 as grow-shy‐out facility for razorback sucker using surplus fish from13 Ouray NationalFish Hatchery National Park Service US Fish and13 Wildlife13 Service and UtahDivision of Wildlife13 Resources 28 pages

Mueller13 G13 and T13 Burke13 200513 Survival13 of young13 razorback13 sucker (Xyrauchen texanus) inrelation to13 stocking rates13 (fishha)13 and13 in the presence13 or absence13 of predatorcommunities in Lake Mohave Arizona-shy‐Nevada13 Pages13 155-shy‐16313 in Proceedings of two13 symposia restoring native fish to the lower Colorado River interaction13 of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 Nevada US Fish and Wildlife13 Service Southwest Region Albuquerque New Mexico

Mueller13 G13 J13 Carpenter13 and P13 C13 Marsh13 200413 Cibola13 High Levee Pond annual report 2004US Geological Survey Fort Collins13 Science Center13 Colorado13 and Arizona StateUniversity Tempe 23 pages

Nesler T P K Christopherson J M Hudson C W McAda F Pfeifer and T E Czapla 2003An integrated stocking plan for razorback sucker bonytail and Colorado13 pikeminnow for the Upper Colorado River Endangered Fish Recovery ProgramAddendum13 to State Stocking Plans Upper Colorado River Basin Recovery13 Implementation Program 12 pp

Papoulias13 D and W13 L Minckley13 1992 Effects13 of foo availability13 on survival and growth13 of larval razorback suckers13 in ponds Transactions of the American Fisheries Society121340-shy‐355

Paukert13 C P D L Ward13 P J Sponholtz13 and K13 D Hilwig13 Effects13 of repeated hoopnetting13 on bonytail chub13 Journal of Freshwater13 Ecology13 20(4) 649-shy‐653

Pfeifer F M13 C Baker13 and M13 Montagne13 199913 Propagation13 facilities13 in the13 Grand Valley13 (24 Road13 Hatchery13 Horsethief13 Ponds and13 grow-shy‐out ponds) for captive rearing of

55

13

endangered13 fishes for the13 Upper Colorado13 River Basin13 Colorado13 River Recovery13 Program FY 99 annual project report Project No 29a13 US Fish and Wildlife Service13 Grand13 Junction13 5pp

Pfeifer F S Seversen and M Montagne 2003 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2003 annual reportProject No 29b13 US Fish and Wildlife13 Service Vernal13 4pp

Rabago-shy‐Castro J L Sanchez13 J G Perez-shy‐Castaneda R and13 Gonzalez-shy‐Gonzlez A 2006Effects of the prophylactic use of Romet-shy‐3013 and13 copper13 sulfate13 on growth13 condition13 and feeding13 indicies in13 channel13 catfish (Ictalurus punctatus) Aquaculture 253 343-shy‐349

Reinitz GL L E Orme and F N Hitzel 1979 Variations of body compositio and growth13 among strains of rainbow trout Transactions of the American Fisheries Society 108204-shy‐207

Ruppert13 J13 B P B Holden13 and P D Abate 1999 Age estimation and growth of razorbacksucker13 Xyrauchen texanus in Lake13 Mead Nevada Proceedings13 of the Desert FishesCouncil 3040

Schnoor K D and J Logan 2002 Operation and maintenance of JW Mumma nativeaquatic13 species restoration facility Colorado Colorado River Recovery Program FY2002 annual project report13 Project No 29d Colorado13 Division of Wildlife Alamosa3pp

Salisbury13 L13 1998 Factors13 affecting razorback13 sucker growth13 in Lake13 Mohave backwaters13 MS Thesis13 Unviersity13 of Nevada13 Las13 Vegas

Schooley J13 D13 and P C13 Marsh13 2007 Stocking of endangerdd13 razorback13 suckers13 in thelower Colorado River Basin13 over three decades 1974-shy‐2004 North American Journalof Fisheries Management 27 43-shy‐51

Severson S H H M Tyus and G B Haines 1992 An evaluation of feeds for raisingrazorback sucker Xyrauchen texanus Journal of Applied Aquaculture 155-shy‐65

Toney D P 1974 Observations13 on the13 propagation13 and13 rearing13 of two13 endangered species13 in a hatchery environment Proceedings of the Annual Conference of the Western13 Association of State Game and Fish Commissions 54 252-shy‐259

Tyus H M13 1998 Razorback sucker13 (Xyrauchen texanus) recovery plan13 University13 ofColorado Center for Limnology Boulder13 76 pages

Tyus H M13 and13 S H Severson 1990 Growth13 and13 survival of larval razorback suckers fedfive formulated diets The Progressive Fish Culturist 52197-shy‐200

56

13

Ulibarri M E 2003 Annual report fiscal year 2001 Dexter National Fish Hatchery13 andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 26 pages

Ulibarri M E 2003 Annual report fiscal year 2002 Dexter National Fish Hatchery andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 59 pages

USBR 2006 Lower13 Colorado13 River Multi-shy‐Species Conservation Program final fishaugmentation plan Boulder City 19 pp

USFWS 2002 Razorback sucker (Xyraouchen texanus) recovery goals Amendment andsupplement to the Razorback Sucker Recovery Plan13 US Fish and Wildlife Service13 Region 6 Denver13 Colorado

USFWS 1999 Annual report 1999 Ouray National Fish Hatchery Vernal 25pp

USFWS 2004 Management plan for the big-shy‐river13 fishes of the13 lower13 Colorado13 river basinamendment and supplement to the bonytail humpback chub Coloradopikeminnow and razorback sucker recovery plans

USFWS13 2005 Station13 profile13 of the13 Dexter13 National Fish Hatchery13 and Technology CenterUS Fish and Wildlife13 Service Dexter

Valdez R A P G Mangan R Smith and B Nilson 1982 Upper Colorado River fisheriesinvestigations13 inW H Miller J J Valentine D L Archer H M Tyus R A Valdezand L13 Kaeding13 editors13 Colorado River Fishery13 Project13 Part 2 Field13 investigations13 US Bureau of Reclamation Salt Lake City Utah

WBNFH 2004 Culture methods of the endangered razorback sucker Xyrauchen texanusUS Fish and Wildlife13 Service Willow Beach National Fish Hatchery13 8 pp

Ward D 2008 Effects of disease treatments on growth of razorback sucker ReportSubmitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 Inpartial fulfillment of work task C10 agreement number 06FG30039

Ward13 D13 M Childs and W Persons 2007 Factors13 affecting13 growth13 of razorback sucker13 (Xyrauchen texanus) in captivity Literature review and knowledge assessmentReport Submitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 In partial fulfillment of work task C10 agreement number 06FG30039

57

Appendices

Appendix 1 Survey Questions Survey of Razorback Sucker Culture in the

Southwestern United States

The enclosed survey is being distributed by the Arizona Game and Fish Department to razorback sucker culture facilities throughout

the Southwestern United States The purpose of this survey is to consolidate information regarding culture of this species so that

appropriate facility improvements can be considered for Bubbling Ponds Hatchery in Arizona Specifically we wish to increase

growth rate and production efficiency at the hatchery Information gathered in this survey will be summarized in a final report to US

Bureau of Reclamation in Boulder City NV and disseminated to all facilities that participate in the survey A workshop to discuss

the findings of this study as well as to share general information concerning razorback sucker culture will be organized by the

Arizona Game and Fish Department at the conclusion of this study and all participants will be invited

Thank you for taking the time to fill out this survey Please contact Mike Childs if you have questions or would like to discuss the

survey

Mike Childs

mchildssedonanet

(928) 639-1346

(928) 634-1279

Facility_____________________________________ Date___________________

Contact Phone _____________________________

ContactPerson_______________________________

Contact Email _______________________________

1 Water quality ranges at this culture facility

Season

Spring (Mar-May) Summer (Jun-Aug) Fall (Sept-Nov) Winter (Dec-Feb)

Temperature (C)

PH

DO (mgL)

PO4 (mgL)

TDS (mgL)

Hardness (mgL)

CaCO3

Pathogens

37

13

13

13

Gro

wth

Rat

e (m

md

ay)

Gro

wth

Rat

e (m

md

ay)

020

026

032

020

026

032

Razorback Growth in an Unlined Pond

Figure 8 Growth of razorbacksuckers (mmday plusmn standard error) in Pond 1 lower (an unlined pond)in 2010-shy‐2011 An ANOVA did notdetect any significant differences

6 Months 12 Months lt 300 mm Fish 300+ mm Fish Growth Growth

Lined vs Earthen Ponds 1 year of growth

Figure 9 Growth of razorbacksuckers (mmday plusmn standard error) in lined and unlined ponds A t-shy‐test13 did not detect a significantdifference

Lined Pond Unlined Pond 1 Yr Growth 1 Yr Growth

45

13

Effect of Sorting G

row

th R

ate

(mm

day

) G

row

th R

ate

(mm

day

)

032

020

026

032

020

026

Smaller Fish Larger Fish

Effect of Ich

Figure 10 Average growthof razorback suckers(mmday plusmn standard error)that were size-shy‐sorted intosmall fish (pond 7) and largefish (pond 8) populations At-shy‐test did not detect asignificant difference

Figure 11 Average growth ofrazorback suckers (mmday plusmnstandard error) after Ich wasremovd from the hatcheryrsquos springand after Ich was again detected inthe pond The growth rate withoutIch is significantly higher than boththe rate after Ich and the ourstudyrsquos average annual growth ratein lined ponds (ANOVA p =00003)

Growth without Ich Growth With Ich Average Annual 4 months 4 months Growth Rate

46

13

Effect of Ich on razorback sucker growth rates

Seventy-shy‐four13 tagged13 razorback suckers13 were13 recovered from13 Pond 8 on September

15 2010 These fish had13 been13 in the pond for 4 months and experienced a growth rate of

032 mmday or 97 mmmonth (Figure13 11)13 This growth13 rate13 is significantly higher (p =

005 two sample t-shy‐test) than the mean growth rate for the same group13 of tagged fish after

Ich detection (022 mmday or 65 mmmonth) and significantly higher than any other

individual growth13 rates13 observed13 to13 date13 at Bubbling13 Ponds Hatchery13 (Figure13 11)13 If this13

growth13 rate13 were13 extended throughout13 the entire13 year13 fish on average from13 Ich-shy‐free13 ponds13

would be 16 mm longer than fish from13 ponds infested with Ich Studies conducted at

Bubbling Ponds hatchery in 2008 (Ward 2008) did not reveal any effects of the treatment

chemicals on razorback sucker growth rates so it13 is likely that13 the parasite outbreaks

themselves are causing reducing growth rates rather than the chemicals used to treat the

parasites13

Conclusions

Our results suggest that under typical hatchery operations (maximizing number of

fish produced)13 the growth13 rate13 of razorback13 suckers13 is relatively13 consistent at Bubbling13

Ponds hatchery13 at 02-shy‐03 mmday (6-shy‐9 mmmonth)13 but is lower than growth13 rates13 at

other13 facilities (02 ndash 18 mmday Ward et al 2007)13 This growth13 rate13 has13 been13 constant in

both lined and unlined ponds and at all fish densities we were able to measure To achieve13

growth13 rates13 substantially higher than this will likely require13 significant changes in rearing

practices that may not be practical in order to reach numerical production13 goals

Temperature is a key variable in fish growth but seasonal growth patterns

described13 above13 (Figure13 5) demonstrate that water temperatures are high enough in

winter to maintain razorback growth Differences in water temperature by season

currently13 do not fluctuate more than 10degC at Bubbling Ponds because of the continuous

supply of water flowing through each pond (approx 225 gallonsmin) These high water

flows appear to keep pond temperatures within the thermal preference13 for razorback

suckers13 (1213 -shy‐ 28 degC Bulkley and Pimentel 1983) throughout the entire year with

temperatures rarely dropping13 below 16deg13 C (Figures 513 6)13

47

13

Fish density is another key variable in fish growth and though the number of fish in

a pond during our study ranged from13 3000 to 700013 fish we13 did not find any13 correlation13

between13 density and growth rate13 This might yield two conclusions First13 razorback

growth13 may be changed equally13 by13 densities13 at the13 hatchery13 (ie13 a density13 of 3000 fish in a

pond is as stressful13 for razorbacks as a density13 of 7000 fish) An alternative is that other

factors13 such as disease outbreaks have13 stronger13 control over fish growth13 than13 density13

Fish density13 would13 have13 to13 be13 experimentally manipulated to test13 this13 and hatchery

operations (producing the maximum13 number of fish) prevented our manipulating density13

in ponds for this13 work The trouble with manipulating density demonstrates the difficulties

associated with changing13 hatchery13 practices experimenting with density would have

prevented BPH from13 meeting13 production13 goals Given that the stocking of smaller

razorbacks has met with very little success perhaps BPH goals could be changed from13

producing 12000 fish at 300+ mm per year to a smaller number of very large fish each

year Growing13 fewer13 larger13 fish could potentially be accomplished in the same time frame

as more smaller fish but a better understanding of how density alters growth rate would

be required to be confident13 of this

The very slow growth13 in the13 earthen13 unlined13 Pond 1 lower13 was very surprising We13

had13 anticipated13 that the13 diversified diet13 cover and13 other13 habitat features13 provided by13

unlined ponds would yield dramatically increased growth rates However these traits were

not enough to offset high fish densities and in fact the unlined pond in our study13 suffered

mortality to bring densities down to that observed normally in lined ponds

Our data13 suggest13 that razorbacks13 sucker13 growth13 rates13 are13 higher in lined13 ponds13

However we13 think the reasons13 for the13 very slow growth we observed13 in the13 unlined13 pond13

in our study13 is instead13 linked13 to13 the13 usage13 of Pond 1 lower13 during13 the13 study13 rather13 than13

intrinsic13 slow growth13 in earthen13 ponds First the pond was at extremely high density for at

least part of the study The volume of Pond 1 lower has not been estimated but hatchery

managers suggest 1500-shy‐2000 fish is an appropriate number of individuals so this pond

was at a very high density for much of the experiment Second dissolved oxygen is often

very low in the13 large13 earthen13 ponds during the heat of summer much lower than that of

lined ponds This will both limit the number of fish that can survive in the pond and almost

certainly13 increases stress13 of these13 fish potentially13 reducing growth13 The DO crashes also13

48

13

limit the amount of feed hatchery managers can give fish in these ponds sometimes for

days or weeks at a time which further reduces growth during warm13 weather

Our data13 suggests that13 growth rates at the Bubbling13 Ponds Fish Hatchery are likely

as high as possible given13 the pond densities required to meet production goals and the Ich-shy‐

infested water that feeds the facility Sorting practices are successful in helping as many

fish as possible reach stocking length as fast as possible Unlined ponds may be able to

grow13 large13 fish at low13 densities13 but whatever factors allow13 for that13 growth are not13 able to

overcome high fish density The removal of invasive13 fis that act as13 a host for the13 parasite13

Ich fish from13 the Bubbling13 Ponds spring13 allowed the highest13 growth rate at 032 mmday13

(96 mmmonth) but that growth rate decreased again as Ich re-shy‐infested13 the13 hatchery13

Consistently13 achieving13 growth13 rates13 as high or substantially13 higher than13 this13 will likely13

require13 significant changes in rearing practices that may not be practical in order to13 reach13

numerical production13 goals

Two major changes that might result in higher growth rates are substantially

reducing fish density and modifying the way spring water is delivered to the facility (via

either repeated chemical treatments or enclosed concrete water diversions) to eliminate

Ich from13 the hatchery source water Other potential changes not address by our work

include13 flow-shy‐training razorbacks much previous literature including MSCP-shy‐funded13 work

on razorback suckers13 suggests13 that fish growing13 in flowing water will grow13 faster than fish

in still water (Jorgensen and Jobling 1994) Furthermore there are a wide variety of

potential benefits associated with growing13 fish13 in flowing13 water in addition13 to increased

growth13 rates13 (Davidson13 199713 Castro13 et al13 2011) Another option13 for increasing13 growth13

rates13 include13 changing to13 intensive13 culture13 in large circular13 tanks

Finally given that the stocking of smaller razorbacks has met with very little

success13 perhaps13 BPH13 goals13 could13 be13 changed from13 producing 12000 fish at 300+ mm per

year to a smaller number of very large fish each year Growing fewer larger fish could

potentially be accomplished in the same time frame as more smaller fish but a better

understanding13 of how density13 alters growth13 rate13 would13 be13 required to13 be13 confident of this

49

13

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower13 Colorado13 River Multi-shy‐Species13

Conservation Program13 (LCRMSCP) under Work Task C10 We13 thank Ty Wolters13 Tom13

Burke13 and Eric13 Volkman for their support of this research and Frank Agygos and Dave

Billingsly13 of the Bubbling13 Ponds Fish Hatchery13 for their willingness to participate in13 this

research13 and13 for their technical assistance We also thank the LCRMSCP fish group from13

Boulder City13 NV for their assistance with harvesting13 ponds and tagging13 fish13

50

13

Literature13 CitedAnders P J 1998 Conservation aquaculture and endangered species can objective science13

prevail13 over risk13 anxiety Fisheries 23(11) 28-shy‐31

Anderson R O and R M Nuemann 1996 Length weight and associated structural indicesPages 447 ndash 482 in B R Murphy13 and D13 W Willis13 editors13 Fisheries techniques13 2ndedtion American Fisheries13 Society13 Bethesda13 Maryland

Bain M B J T Finn and H E Brooks 1988 Streamflow regulation and fish communitystructure13 Ecology13 69382-shy‐392

Bays J H Zarbock R Whitman and T Murphy 2005 Conceptual design and managementof native13 fish refugia on the13 lower13 Colorado13 River In13 CL Spring13 and13 S Leoneditors Proceedings of two symposia Restoring native fish to the lower ColoradoRiver13 interactions13 of native and non-shy‐native13 fishes 13ndash1413 July13 1999 Las13 Vegas13 Nevada13 Restoring13 natural function within a modified riverine environment thelower Colorado River13 8ndash913 July13 1998 U S Fish and13 Wildlife13 Service Southwestern13 Region Albuquerque New Mexico Pages 167-shy‐177

Bertalanffy L Von 1957 Quantitative laws in metabolism13 and growth13 Q Rev Biology 32217 ndash 231

Bingham T B Scheer and C McAda 2003 Propagation facilities in Grand Valley (24 RoadHatchery Horsethief13 Ponds and13 grow-shy‐out ponds) for captive13 rearing13 ofendangered13 fishes for the13 upper13 Colorado13 River basin13 Colorado River RecoveryProgram FY2003 annual project report13 US Fish and13 Wildlife13 Service GrandJunction13 4pp

Birchell G J and K Christopherson 2004 Survival growth and recruitment of larval andjuvenile razorback13 sucker (Xyrauchen texanus) introduced13 into13 floodplain13 depressions13 of the13 Green River Utah13 Final report13 Upper13 Colorado13 RiverEndangered Fish Recovery Program13 Project No C-shy‐6RZ Publication Number 04-shy‐1513 Utah13 Division of Wildlife13 Resources Salt Lake13 City13 Utah13 67 pages

Brannon E L 1993 The perpetual oversight of hatchery programs Fishery Research 1819-shy‐27

Brett J R 1979 Environmental Factors and growth pages 599-shy‐67513 InW S Hoar13 D13 J13 Randall and J R Brett (eds) Fish Physiology Volume 8 Bioenergetics and GrowthAcademic Press New York

Brooks J E 1986 Annual reintroduction and monitoring report for razorback suckerXyrauchen texanus in the Gila River Basin Arizona 1985 US Fish and WildlifeService13 Offices of Endangered13 Species and Fishery13 Resources Albuquerque 23 pp

51

13

Brunson13 R E and K D13 Christopherson13 200513 Larval13 razorback13 sucker and bonytailsurvival and13 growth13 in the13 presence13 of nonnative13 fish in the13 Baeser13 floodplainwetland of the middle Green River Final report prepared for Upper13 Colorado RiverBasin Endangered Fish Recovery Program Project No C-shy‐6-shy‐rz-shy‐bt Publication13 No 05-shy‐26 Utah13 Division of Wildlife13 Resources13 Vernal13 32 pp

Bulkley R V and R Pimentel 1983 Temperature preference and avoidance by adultrazorback suckers Transactions of the American Fisheries Society 112601-shy‐607

Burke13 T13 199513 Rearing13 wild razorback13 sucker larvae in13 lake-shy‐side13 backwaters13 LakeMohave ArizonaNevada Proceedings of the Desert Fishes Council 2635

Busacker G P I R Adelman and E M Goolish13 199013 Growth13 Pages 363 ndash 387 in C BSchreck and p B Moyle editors Methods for fish biology American FisheriesSociety Bethesda Maryland

Castro V B Grisdale-shy‐Helland S J Helland T Kristensen S M Jorgensen J Helgrud13 GClaireaux A P Farrell A Krasnov and H Takle 2011 Aerobic training stimulatesgrowth and promotes disease resistance in Atlantic salmon (Salmo salar)Comparative Biochemistry and Physiology -shy‐ Part A Molecular amp IntegrativePhysiology13 160(2) 278-shy‐290

Czapla T E 2002 Facilities plan for the production of endangered fishes to meet statestocking13 plans13 as13 part of the13 Upper13 Colorado13 River Endangered13 Fish RecoveryProgram Upper Colorado River Basin Recovery Implementation Program US Fishand Wildlife Service13 Denver13 9 pp

Davidson W 1997 The effects13 of exercise13 training on teleost fish a review of recentliterature Comput Biochem Physiol 117A67ndash75

Figiel Jr C R 2005 Annual report fiscal year 2004 Willow Beach National13 Fish HatcheryUS Fish and Wildlife13 Service Willow Beach 17 pp

Figiel Jr C R M E Ulibarri G Carmichael J Seals and J N Hanson 2005 Intensive13 fish13 culture of warmwater native fishes at a coldwater fish hatchery Pages 164-shy‐16613 inProceedings of two symposia restoring native fish to the lower Colorado13 River13 interaction13 of native13 and13 non-shy‐native13 fishes July13 13-shy‐1413 1999 Las Vegas Nevada USFish and Wildlife Service Southwest Region Albuquerque New Mexico

Gerking13 S D 1978 Ecology of freshwater fish13 production13 Halstead Press13 New13 York

Gustafson W and Q Bradwisch 2000 Wahweap operation and maintenance -shy‐-shy‐ UtahColorado River Recovery Program FY 2000 annual project report Project No 29cUtah13 Division of Wildlife13 Resources Page AZ 3pp

52

13

Hamman R L 1985 Induced spawning of hatchery-shy‐reared13 razorback sucker ProgressivFish Culturist 47(3) 187-shy‐189

Hanson J N 1996 Annual report fiscal year 1996 Willow Beach National Fish HatcheryUS Fish and Wildlife Service13 Willow Beach 9pp

Irving D S Seversen and M Montagne 2004 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2004 annual project13 report Report No 29b US Fish and13 Wildlife13 Service Vernal 3pp

Jorgensen E H and13 M Jobling 1994 Feeding and13 growth13 of exercised13 and13 unexercised13 juvenile Atlantic salmon in freshwater and performance after transfer to seawaterAquaculture International 2 154-shy‐164

Kaeding L R and D B Osmundson 198913 Colorado13 Squawfish13 and13 razorback sucker grow-shy‐out pond studies as part of conservation measures for the green mountain andRuedi reservoir water sales Final report for agreement number 6-shy‐AA-shy‐60-shy‐00150

Koebele13 B P13 198513 Growth and the size hierarchy effect an experimental assessment ofthree proposed mechanisms activity differences disproportional food acquisition13 pysiological stress Environmental Biology of Fishes 12 181-shy‐188

Kretschmann A E and L L Leslie 2006 Razorback sucker (Xyrauchen texanus) status13 reproduction and recruitment in Senator Wash Reservoir CA Final Report13 to USBurea of Reclamation Cooperative Agreement No 00-shy‐FG-shy‐34-shy‐ 0009 p 32 ArizonaGame and Fish Department Phoenix

Marsh13 P13 C13 1987a13 Digestive tract13 contents13 of adult razorback suckers13 in Lake13 MohaveArizona-shy‐Nevada Transactions of the American Fisheries Society 116117-shy‐119

Marsh P C 1987b Native fishes at Buenos Aires National Wildlife Refuge and ArizonaState University Research Park Arizona opportunities for management researchand public13 education13 on13 endangered species13 Proceedings of the Desert13 FishesCouncil 1967-shy‐78

Marsh P C 1994 Rearing native Colorado River fishes in golf course ponds Arizona StateUniversity Tempe 22 + pages

Marsh13 P13 C13 200013 Fish population13 status and evaluation13 in13 the Cibola13 High Levee PondFinal report agreement number 99-shy‐FG-shy‐30-shy‐00051 US Bureau of ReclamationBoulder City13 Nevada13 20 pages

Marsh P C and C A Pacey 1998 Growth of wild adult razorback suckers13 in Lake13 Mohave13 Arizona-shy‐Nevada13 Final report13 US Bureau of Reclamation Boulder City Nevada 25pages + appendices

53

13

Marsh P C B R Kesner and C A Pacey 2005 Repatriation as s management strategy13 to13 conserve a critically13 imperiled fish species North American Journal of FisheriesManagement 25 547-shy‐556

Marsh P C and C A Pacey 2005 Immiscibility of native and non-shy‐native13 fishes Pages 59-shy‐63 inMJ13 Brouder13 CL13 Springer13 and CS13 Leon13 editors13 Proceedings of two13 symposia Restoring native fish to the lower Colorado River interactions of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 NV and13 Restoring natural13 function within a modified riverine environment the lower Colorado River13 July13 8-shy‐913 1998 Las Vegas NV US Fish and13 Wildlife13 Service Southwest Region AlbuquerqueNew Mexico

Marsh13 P13 C13 and J13 E Brooks13 198913 Predation13 by ictalurid catfishes as a deterrent13 toreestablishment of hatchery-shy‐reared13 razorback sucker The Southwestern Naturalist34188-shy‐195

Matthews R A 2005 Ichthyopthirus multifiliis Fouquet and Ichthyopthirosis infreshwater13 teleosts13 Pages13 159-shy‐218 in Advances in Parasitology volume 59 J RBaker R Muller D Rollinson (eds) Academic Press

McCarthy13 M S and W L Minckley 1987 Age estimation for razorback sucker (PiscesCatostomidae) from13 Lake Mohave Arizona and Nevada Journal of the Arizona-shy‐Nevada Academy of Science 2187-shy‐97

Minckley13 W L13 198313 Status of the razorback13 sucker13 Xyrauchen texanus (Abbot)13 in13 thelower Colorado River basin13 The Southwestern13 Naturalist13 28(2) 165-shy‐187

Minckley13 W L13 199113 Native fished of the Grand Canyon13 region an obituary13 Pages 124-shy‐177 in Colorado River ecology and dam13 management National Academy PressWashington13 DC

Minckley13 C13 O and M LaBarbara13 199913 Report13 on13 native fish grow-shy‐out facilities13 at Cibolaand Imperial National Wildlife Refuges 1993-shy‐199513 US Fish and13 Wildlife Service13 Parker Fishery Resources Office Parker Arizona

Modde13 T13 199613 Juvenile razorback sucker (Xyrauchen texanus) in a managed wetlandadjacent13 to the Green13 River13 Great13 Basin13 Naturalist13 56375-shy‐376

Modde T KP Burnham and E J Wick 1996 Population status of the razorback sucker13 inthe middle Green River (USA) Conservation13 biology 10 110-shy‐119

Modde13 T13 and G13 B Haines13 200513 Survival13 and growth of stocked razorback13 sucker andbonytail in multiple floodplain wetlands of the middle Green River under resetconditions13 Final report prepared for Upper Colorado13 River13 Basin RecoveryImplimentation Program US Fish and Wildlife Service Vernal 66 pp

54

13

Modde T Z H Bowen and D C Kitcheyan 2005 Spatial and temporal use of a spawning13 site in the middle Green River by wild hatchery-shy‐reared13 razorback suckers13 Transactions of the American Fisheries Society 134937-shy‐944

Mueller13 G13 199213 The native fish work13 group13 -shy‐ a multiagency endeavor to improve thestatus of the razorback sucker in Lake Mohave AZ-shy‐NV13 Proceedings of the DesertFishes Council 2369

Mueller G 1995 A program13 for maintaining the razorback sucker in Lake MohaveAmerican Fisheries Society Symposium 15127-shy‐135

Mueller13 G13 200613 Ecology of the bonytail13 and razorback13 sucker and the role of offchannelhabitats13 in their13 recovery Scientific13 investigations13 report 2006-shy‐5065 US GeologicalSurvey13 Denver

Mueller G and E Wick 1998 Testing of golf course ponds at Page Arizona for suitability13 as grow-shy‐out facility for razorback sucker using surplus fish from13 Ouray NationalFish Hatchery National Park Service US Fish and13 Wildlife13 Service and UtahDivision of Wildlife13 Resources 28 pages

Mueller13 G13 and T13 Burke13 200513 Survival13 of young13 razorback13 sucker (Xyrauchen texanus) inrelation to13 stocking rates13 (fishha)13 and13 in the presence13 or absence13 of predatorcommunities in Lake Mohave Arizona-shy‐Nevada13 Pages13 155-shy‐16313 in Proceedings of two13 symposia restoring native fish to the lower Colorado River interaction13 of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 Nevada US Fish and Wildlife13 Service Southwest Region Albuquerque New Mexico

Mueller13 G13 J13 Carpenter13 and P13 C13 Marsh13 200413 Cibola13 High Levee Pond annual report 2004US Geological Survey Fort Collins13 Science Center13 Colorado13 and Arizona StateUniversity Tempe 23 pages

Nesler T P K Christopherson J M Hudson C W McAda F Pfeifer and T E Czapla 2003An integrated stocking plan for razorback sucker bonytail and Colorado13 pikeminnow for the Upper Colorado River Endangered Fish Recovery ProgramAddendum13 to State Stocking Plans Upper Colorado River Basin Recovery13 Implementation Program 12 pp

Papoulias13 D and W13 L Minckley13 1992 Effects13 of foo availability13 on survival and growth13 of larval razorback suckers13 in ponds Transactions of the American Fisheries Society121340-shy‐355

Paukert13 C P D L Ward13 P J Sponholtz13 and K13 D Hilwig13 Effects13 of repeated hoopnetting13 on bonytail chub13 Journal of Freshwater13 Ecology13 20(4) 649-shy‐653

Pfeifer F M13 C Baker13 and M13 Montagne13 199913 Propagation13 facilities13 in the13 Grand Valley13 (24 Road13 Hatchery13 Horsethief13 Ponds and13 grow-shy‐out ponds) for captive rearing of

55

13

endangered13 fishes for the13 Upper Colorado13 River Basin13 Colorado13 River Recovery13 Program FY 99 annual project report Project No 29a13 US Fish and Wildlife Service13 Grand13 Junction13 5pp

Pfeifer F S Seversen and M Montagne 2003 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2003 annual reportProject No 29b13 US Fish and Wildlife13 Service Vernal13 4pp

Rabago-shy‐Castro J L Sanchez13 J G Perez-shy‐Castaneda R and13 Gonzalez-shy‐Gonzlez A 2006Effects of the prophylactic use of Romet-shy‐3013 and13 copper13 sulfate13 on growth13 condition13 and feeding13 indicies in13 channel13 catfish (Ictalurus punctatus) Aquaculture 253 343-shy‐349

Reinitz GL L E Orme and F N Hitzel 1979 Variations of body compositio and growth13 among strains of rainbow trout Transactions of the American Fisheries Society 108204-shy‐207

Ruppert13 J13 B P B Holden13 and P D Abate 1999 Age estimation and growth of razorbacksucker13 Xyrauchen texanus in Lake13 Mead Nevada Proceedings13 of the Desert FishesCouncil 3040

Schnoor K D and J Logan 2002 Operation and maintenance of JW Mumma nativeaquatic13 species restoration facility Colorado Colorado River Recovery Program FY2002 annual project report13 Project No 29d Colorado13 Division of Wildlife Alamosa3pp

Salisbury13 L13 1998 Factors13 affecting razorback13 sucker growth13 in Lake13 Mohave backwaters13 MS Thesis13 Unviersity13 of Nevada13 Las13 Vegas

Schooley J13 D13 and P C13 Marsh13 2007 Stocking of endangerdd13 razorback13 suckers13 in thelower Colorado River Basin13 over three decades 1974-shy‐2004 North American Journalof Fisheries Management 27 43-shy‐51

Severson S H H M Tyus and G B Haines 1992 An evaluation of feeds for raisingrazorback sucker Xyrauchen texanus Journal of Applied Aquaculture 155-shy‐65

Toney D P 1974 Observations13 on the13 propagation13 and13 rearing13 of two13 endangered species13 in a hatchery environment Proceedings of the Annual Conference of the Western13 Association of State Game and Fish Commissions 54 252-shy‐259

Tyus H M13 1998 Razorback sucker13 (Xyrauchen texanus) recovery plan13 University13 ofColorado Center for Limnology Boulder13 76 pages

Tyus H M13 and13 S H Severson 1990 Growth13 and13 survival of larval razorback suckers fedfive formulated diets The Progressive Fish Culturist 52197-shy‐200

56

13

Ulibarri M E 2003 Annual report fiscal year 2001 Dexter National Fish Hatchery13 andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 26 pages

Ulibarri M E 2003 Annual report fiscal year 2002 Dexter National Fish Hatchery andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 59 pages

USBR 2006 Lower13 Colorado13 River Multi-shy‐Species Conservation Program final fishaugmentation plan Boulder City 19 pp

USFWS 2002 Razorback sucker (Xyraouchen texanus) recovery goals Amendment andsupplement to the Razorback Sucker Recovery Plan13 US Fish and Wildlife Service13 Region 6 Denver13 Colorado

USFWS 1999 Annual report 1999 Ouray National Fish Hatchery Vernal 25pp

USFWS 2004 Management plan for the big-shy‐river13 fishes of the13 lower13 Colorado13 river basinamendment and supplement to the bonytail humpback chub Coloradopikeminnow and razorback sucker recovery plans

USFWS13 2005 Station13 profile13 of the13 Dexter13 National Fish Hatchery13 and Technology CenterUS Fish and Wildlife13 Service Dexter

Valdez R A P G Mangan R Smith and B Nilson 1982 Upper Colorado River fisheriesinvestigations13 inW H Miller J J Valentine D L Archer H M Tyus R A Valdezand L13 Kaeding13 editors13 Colorado River Fishery13 Project13 Part 2 Field13 investigations13 US Bureau of Reclamation Salt Lake City Utah

WBNFH 2004 Culture methods of the endangered razorback sucker Xyrauchen texanusUS Fish and Wildlife13 Service Willow Beach National Fish Hatchery13 8 pp

Ward D 2008 Effects of disease treatments on growth of razorback sucker ReportSubmitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 Inpartial fulfillment of work task C10 agreement number 06FG30039

Ward13 D13 M Childs and W Persons 2007 Factors13 affecting13 growth13 of razorback sucker13 (Xyrauchen texanus) in captivity Literature review and knowledge assessmentReport Submitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 In partial fulfillment of work task C10 agreement number 06FG30039

57

Appendices

Appendix 1 Survey Questions Survey of Razorback Sucker Culture in the

Southwestern United States

The enclosed survey is being distributed by the Arizona Game and Fish Department to razorback sucker culture facilities throughout

the Southwestern United States The purpose of this survey is to consolidate information regarding culture of this species so that

appropriate facility improvements can be considered for Bubbling Ponds Hatchery in Arizona Specifically we wish to increase

growth rate and production efficiency at the hatchery Information gathered in this survey will be summarized in a final report to US

Bureau of Reclamation in Boulder City NV and disseminated to all facilities that participate in the survey A workshop to discuss

the findings of this study as well as to share general information concerning razorback sucker culture will be organized by the

Arizona Game and Fish Department at the conclusion of this study and all participants will be invited

Thank you for taking the time to fill out this survey Please contact Mike Childs if you have questions or would like to discuss the

survey

Mike Childs

mchildssedonanet

(928) 639-1346

(928) 634-1279

Facility_____________________________________ Date___________________

Contact Phone _____________________________

ContactPerson_______________________________

Contact Email _______________________________

1 Water quality ranges at this culture facility

Season

Spring (Mar-May) Summer (Jun-Aug) Fall (Sept-Nov) Winter (Dec-Feb)

Temperature (C)

PH

DO (mgL)

PO4 (mgL)

TDS (mgL)

Hardness (mgL)

CaCO3

Pathogens

37

13

Effect of Sorting G

row

th R

ate

(mm

day

) G

row

th R

ate

(mm

day

)

032

020

026

032

020

026

Smaller Fish Larger Fish

Effect of Ich

Figure 10 Average growthof razorback suckers(mmday plusmn standard error)that were size-shy‐sorted intosmall fish (pond 7) and largefish (pond 8) populations At-shy‐test did not detect asignificant difference

Figure 11 Average growth ofrazorback suckers (mmday plusmnstandard error) after Ich wasremovd from the hatcheryrsquos springand after Ich was again detected inthe pond The growth rate withoutIch is significantly higher than boththe rate after Ich and the ourstudyrsquos average annual growth ratein lined ponds (ANOVA p =00003)

Growth without Ich Growth With Ich Average Annual 4 months 4 months Growth Rate

46

13

Effect of Ich on razorback sucker growth rates

Seventy-shy‐four13 tagged13 razorback suckers13 were13 recovered from13 Pond 8 on September

15 2010 These fish had13 been13 in the pond for 4 months and experienced a growth rate of

032 mmday or 97 mmmonth (Figure13 11)13 This growth13 rate13 is significantly higher (p =

005 two sample t-shy‐test) than the mean growth rate for the same group13 of tagged fish after

Ich detection (022 mmday or 65 mmmonth) and significantly higher than any other

individual growth13 rates13 observed13 to13 date13 at Bubbling13 Ponds Hatchery13 (Figure13 11)13 If this13

growth13 rate13 were13 extended throughout13 the entire13 year13 fish on average from13 Ich-shy‐free13 ponds13

would be 16 mm longer than fish from13 ponds infested with Ich Studies conducted at

Bubbling Ponds hatchery in 2008 (Ward 2008) did not reveal any effects of the treatment

chemicals on razorback sucker growth rates so it13 is likely that13 the parasite outbreaks

themselves are causing reducing growth rates rather than the chemicals used to treat the

parasites13

Conclusions

Our results suggest that under typical hatchery operations (maximizing number of

fish produced)13 the growth13 rate13 of razorback13 suckers13 is relatively13 consistent at Bubbling13

Ponds hatchery13 at 02-shy‐03 mmday (6-shy‐9 mmmonth)13 but is lower than growth13 rates13 at

other13 facilities (02 ndash 18 mmday Ward et al 2007)13 This growth13 rate13 has13 been13 constant in

both lined and unlined ponds and at all fish densities we were able to measure To achieve13

growth13 rates13 substantially higher than this will likely require13 significant changes in rearing

practices that may not be practical in order to reach numerical production13 goals

Temperature is a key variable in fish growth but seasonal growth patterns

described13 above13 (Figure13 5) demonstrate that water temperatures are high enough in

winter to maintain razorback growth Differences in water temperature by season

currently13 do not fluctuate more than 10degC at Bubbling Ponds because of the continuous

supply of water flowing through each pond (approx 225 gallonsmin) These high water

flows appear to keep pond temperatures within the thermal preference13 for razorback

suckers13 (1213 -shy‐ 28 degC Bulkley and Pimentel 1983) throughout the entire year with

temperatures rarely dropping13 below 16deg13 C (Figures 513 6)13

47

13

Fish density is another key variable in fish growth and though the number of fish in

a pond during our study ranged from13 3000 to 700013 fish we13 did not find any13 correlation13

between13 density and growth rate13 This might yield two conclusions First13 razorback

growth13 may be changed equally13 by13 densities13 at the13 hatchery13 (ie13 a density13 of 3000 fish in a

pond is as stressful13 for razorbacks as a density13 of 7000 fish) An alternative is that other

factors13 such as disease outbreaks have13 stronger13 control over fish growth13 than13 density13

Fish density13 would13 have13 to13 be13 experimentally manipulated to test13 this13 and hatchery

operations (producing the maximum13 number of fish) prevented our manipulating density13

in ponds for this13 work The trouble with manipulating density demonstrates the difficulties

associated with changing13 hatchery13 practices experimenting with density would have

prevented BPH from13 meeting13 production13 goals Given that the stocking of smaller

razorbacks has met with very little success perhaps BPH goals could be changed from13

producing 12000 fish at 300+ mm per year to a smaller number of very large fish each

year Growing13 fewer13 larger13 fish could potentially be accomplished in the same time frame

as more smaller fish but a better understanding of how density alters growth rate would

be required to be confident13 of this

The very slow growth13 in the13 earthen13 unlined13 Pond 1 lower13 was very surprising We13

had13 anticipated13 that the13 diversified diet13 cover and13 other13 habitat features13 provided by13

unlined ponds would yield dramatically increased growth rates However these traits were

not enough to offset high fish densities and in fact the unlined pond in our study13 suffered

mortality to bring densities down to that observed normally in lined ponds

Our data13 suggest13 that razorbacks13 sucker13 growth13 rates13 are13 higher in lined13 ponds13

However we13 think the reasons13 for the13 very slow growth we observed13 in the13 unlined13 pond13

in our study13 is instead13 linked13 to13 the13 usage13 of Pond 1 lower13 during13 the13 study13 rather13 than13

intrinsic13 slow growth13 in earthen13 ponds First the pond was at extremely high density for at

least part of the study The volume of Pond 1 lower has not been estimated but hatchery

managers suggest 1500-shy‐2000 fish is an appropriate number of individuals so this pond

was at a very high density for much of the experiment Second dissolved oxygen is often

very low in the13 large13 earthen13 ponds during the heat of summer much lower than that of

lined ponds This will both limit the number of fish that can survive in the pond and almost

certainly13 increases stress13 of these13 fish potentially13 reducing growth13 The DO crashes also13

48

13

limit the amount of feed hatchery managers can give fish in these ponds sometimes for

days or weeks at a time which further reduces growth during warm13 weather

Our data13 suggests that13 growth rates at the Bubbling13 Ponds Fish Hatchery are likely

as high as possible given13 the pond densities required to meet production goals and the Ich-shy‐

infested water that feeds the facility Sorting practices are successful in helping as many

fish as possible reach stocking length as fast as possible Unlined ponds may be able to

grow13 large13 fish at low13 densities13 but whatever factors allow13 for that13 growth are not13 able to

overcome high fish density The removal of invasive13 fis that act as13 a host for the13 parasite13

Ich fish from13 the Bubbling13 Ponds spring13 allowed the highest13 growth rate at 032 mmday13

(96 mmmonth) but that growth rate decreased again as Ich re-shy‐infested13 the13 hatchery13

Consistently13 achieving13 growth13 rates13 as high or substantially13 higher than13 this13 will likely13

require13 significant changes in rearing practices that may not be practical in order to13 reach13

numerical production13 goals

Two major changes that might result in higher growth rates are substantially

reducing fish density and modifying the way spring water is delivered to the facility (via

either repeated chemical treatments or enclosed concrete water diversions) to eliminate

Ich from13 the hatchery source water Other potential changes not address by our work

include13 flow-shy‐training razorbacks much previous literature including MSCP-shy‐funded13 work

on razorback suckers13 suggests13 that fish growing13 in flowing water will grow13 faster than fish

in still water (Jorgensen and Jobling 1994) Furthermore there are a wide variety of

potential benefits associated with growing13 fish13 in flowing13 water in addition13 to increased

growth13 rates13 (Davidson13 199713 Castro13 et al13 2011) Another option13 for increasing13 growth13

rates13 include13 changing to13 intensive13 culture13 in large circular13 tanks

Finally given that the stocking of smaller razorbacks has met with very little

success13 perhaps13 BPH13 goals13 could13 be13 changed from13 producing 12000 fish at 300+ mm per

year to a smaller number of very large fish each year Growing fewer larger fish could

potentially be accomplished in the same time frame as more smaller fish but a better

understanding13 of how density13 alters growth13 rate13 would13 be13 required to13 be13 confident of this

49

13

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower13 Colorado13 River Multi-shy‐Species13

Conservation Program13 (LCRMSCP) under Work Task C10 We13 thank Ty Wolters13 Tom13

Burke13 and Eric13 Volkman for their support of this research and Frank Agygos and Dave

Billingsly13 of the Bubbling13 Ponds Fish Hatchery13 for their willingness to participate in13 this

research13 and13 for their technical assistance We also thank the LCRMSCP fish group from13

Boulder City13 NV for their assistance with harvesting13 ponds and tagging13 fish13

50

13

Literature13 CitedAnders P J 1998 Conservation aquaculture and endangered species can objective science13

prevail13 over risk13 anxiety Fisheries 23(11) 28-shy‐31

Anderson R O and R M Nuemann 1996 Length weight and associated structural indicesPages 447 ndash 482 in B R Murphy13 and D13 W Willis13 editors13 Fisheries techniques13 2ndedtion American Fisheries13 Society13 Bethesda13 Maryland

Bain M B J T Finn and H E Brooks 1988 Streamflow regulation and fish communitystructure13 Ecology13 69382-shy‐392

Bays J H Zarbock R Whitman and T Murphy 2005 Conceptual design and managementof native13 fish refugia on the13 lower13 Colorado13 River In13 CL Spring13 and13 S Leoneditors Proceedings of two symposia Restoring native fish to the lower ColoradoRiver13 interactions13 of native and non-shy‐native13 fishes 13ndash1413 July13 1999 Las13 Vegas13 Nevada13 Restoring13 natural function within a modified riverine environment thelower Colorado River13 8ndash913 July13 1998 U S Fish and13 Wildlife13 Service Southwestern13 Region Albuquerque New Mexico Pages 167-shy‐177

Bertalanffy L Von 1957 Quantitative laws in metabolism13 and growth13 Q Rev Biology 32217 ndash 231

Bingham T B Scheer and C McAda 2003 Propagation facilities in Grand Valley (24 RoadHatchery Horsethief13 Ponds and13 grow-shy‐out ponds) for captive13 rearing13 ofendangered13 fishes for the13 upper13 Colorado13 River basin13 Colorado River RecoveryProgram FY2003 annual project report13 US Fish and13 Wildlife13 Service GrandJunction13 4pp

Birchell G J and K Christopherson 2004 Survival growth and recruitment of larval andjuvenile razorback13 sucker (Xyrauchen texanus) introduced13 into13 floodplain13 depressions13 of the13 Green River Utah13 Final report13 Upper13 Colorado13 RiverEndangered Fish Recovery Program13 Project No C-shy‐6RZ Publication Number 04-shy‐1513 Utah13 Division of Wildlife13 Resources Salt Lake13 City13 Utah13 67 pages

Brannon E L 1993 The perpetual oversight of hatchery programs Fishery Research 1819-shy‐27

Brett J R 1979 Environmental Factors and growth pages 599-shy‐67513 InW S Hoar13 D13 J13 Randall and J R Brett (eds) Fish Physiology Volume 8 Bioenergetics and GrowthAcademic Press New York

Brooks J E 1986 Annual reintroduction and monitoring report for razorback suckerXyrauchen texanus in the Gila River Basin Arizona 1985 US Fish and WildlifeService13 Offices of Endangered13 Species and Fishery13 Resources Albuquerque 23 pp

51

13

Brunson13 R E and K D13 Christopherson13 200513 Larval13 razorback13 sucker and bonytailsurvival and13 growth13 in the13 presence13 of nonnative13 fish in the13 Baeser13 floodplainwetland of the middle Green River Final report prepared for Upper13 Colorado RiverBasin Endangered Fish Recovery Program Project No C-shy‐6-shy‐rz-shy‐bt Publication13 No 05-shy‐26 Utah13 Division of Wildlife13 Resources13 Vernal13 32 pp

Bulkley R V and R Pimentel 1983 Temperature preference and avoidance by adultrazorback suckers Transactions of the American Fisheries Society 112601-shy‐607

Burke13 T13 199513 Rearing13 wild razorback13 sucker larvae in13 lake-shy‐side13 backwaters13 LakeMohave ArizonaNevada Proceedings of the Desert Fishes Council 2635

Busacker G P I R Adelman and E M Goolish13 199013 Growth13 Pages 363 ndash 387 in C BSchreck and p B Moyle editors Methods for fish biology American FisheriesSociety Bethesda Maryland

Castro V B Grisdale-shy‐Helland S J Helland T Kristensen S M Jorgensen J Helgrud13 GClaireaux A P Farrell A Krasnov and H Takle 2011 Aerobic training stimulatesgrowth and promotes disease resistance in Atlantic salmon (Salmo salar)Comparative Biochemistry and Physiology -shy‐ Part A Molecular amp IntegrativePhysiology13 160(2) 278-shy‐290

Czapla T E 2002 Facilities plan for the production of endangered fishes to meet statestocking13 plans13 as13 part of the13 Upper13 Colorado13 River Endangered13 Fish RecoveryProgram Upper Colorado River Basin Recovery Implementation Program US Fishand Wildlife Service13 Denver13 9 pp

Davidson W 1997 The effects13 of exercise13 training on teleost fish a review of recentliterature Comput Biochem Physiol 117A67ndash75

Figiel Jr C R 2005 Annual report fiscal year 2004 Willow Beach National13 Fish HatcheryUS Fish and Wildlife13 Service Willow Beach 17 pp

Figiel Jr C R M E Ulibarri G Carmichael J Seals and J N Hanson 2005 Intensive13 fish13 culture of warmwater native fishes at a coldwater fish hatchery Pages 164-shy‐16613 inProceedings of two symposia restoring native fish to the lower Colorado13 River13 interaction13 of native13 and13 non-shy‐native13 fishes July13 13-shy‐1413 1999 Las Vegas Nevada USFish and Wildlife Service Southwest Region Albuquerque New Mexico

Gerking13 S D 1978 Ecology of freshwater fish13 production13 Halstead Press13 New13 York

Gustafson W and Q Bradwisch 2000 Wahweap operation and maintenance -shy‐-shy‐ UtahColorado River Recovery Program FY 2000 annual project report Project No 29cUtah13 Division of Wildlife13 Resources Page AZ 3pp

52

13

Hamman R L 1985 Induced spawning of hatchery-shy‐reared13 razorback sucker ProgressivFish Culturist 47(3) 187-shy‐189

Hanson J N 1996 Annual report fiscal year 1996 Willow Beach National Fish HatcheryUS Fish and Wildlife Service13 Willow Beach 9pp

Irving D S Seversen and M Montagne 2004 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2004 annual project13 report Report No 29b US Fish and13 Wildlife13 Service Vernal 3pp

Jorgensen E H and13 M Jobling 1994 Feeding and13 growth13 of exercised13 and13 unexercised13 juvenile Atlantic salmon in freshwater and performance after transfer to seawaterAquaculture International 2 154-shy‐164

Kaeding L R and D B Osmundson 198913 Colorado13 Squawfish13 and13 razorback sucker grow-shy‐out pond studies as part of conservation measures for the green mountain andRuedi reservoir water sales Final report for agreement number 6-shy‐AA-shy‐60-shy‐00150

Koebele13 B P13 198513 Growth and the size hierarchy effect an experimental assessment ofthree proposed mechanisms activity differences disproportional food acquisition13 pysiological stress Environmental Biology of Fishes 12 181-shy‐188

Kretschmann A E and L L Leslie 2006 Razorback sucker (Xyrauchen texanus) status13 reproduction and recruitment in Senator Wash Reservoir CA Final Report13 to USBurea of Reclamation Cooperative Agreement No 00-shy‐FG-shy‐34-shy‐ 0009 p 32 ArizonaGame and Fish Department Phoenix

Marsh13 P13 C13 1987a13 Digestive tract13 contents13 of adult razorback suckers13 in Lake13 MohaveArizona-shy‐Nevada Transactions of the American Fisheries Society 116117-shy‐119

Marsh P C 1987b Native fishes at Buenos Aires National Wildlife Refuge and ArizonaState University Research Park Arizona opportunities for management researchand public13 education13 on13 endangered species13 Proceedings of the Desert13 FishesCouncil 1967-shy‐78

Marsh P C 1994 Rearing native Colorado River fishes in golf course ponds Arizona StateUniversity Tempe 22 + pages

Marsh13 P13 C13 200013 Fish population13 status and evaluation13 in13 the Cibola13 High Levee PondFinal report agreement number 99-shy‐FG-shy‐30-shy‐00051 US Bureau of ReclamationBoulder City13 Nevada13 20 pages

Marsh P C and C A Pacey 1998 Growth of wild adult razorback suckers13 in Lake13 Mohave13 Arizona-shy‐Nevada13 Final report13 US Bureau of Reclamation Boulder City Nevada 25pages + appendices

53

13

Marsh P C B R Kesner and C A Pacey 2005 Repatriation as s management strategy13 to13 conserve a critically13 imperiled fish species North American Journal of FisheriesManagement 25 547-shy‐556

Marsh P C and C A Pacey 2005 Immiscibility of native and non-shy‐native13 fishes Pages 59-shy‐63 inMJ13 Brouder13 CL13 Springer13 and CS13 Leon13 editors13 Proceedings of two13 symposia Restoring native fish to the lower Colorado River interactions of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 NV and13 Restoring natural13 function within a modified riverine environment the lower Colorado River13 July13 8-shy‐913 1998 Las Vegas NV US Fish and13 Wildlife13 Service Southwest Region AlbuquerqueNew Mexico

Marsh13 P13 C13 and J13 E Brooks13 198913 Predation13 by ictalurid catfishes as a deterrent13 toreestablishment of hatchery-shy‐reared13 razorback sucker The Southwestern Naturalist34188-shy‐195

Matthews R A 2005 Ichthyopthirus multifiliis Fouquet and Ichthyopthirosis infreshwater13 teleosts13 Pages13 159-shy‐218 in Advances in Parasitology volume 59 J RBaker R Muller D Rollinson (eds) Academic Press

McCarthy13 M S and W L Minckley 1987 Age estimation for razorback sucker (PiscesCatostomidae) from13 Lake Mohave Arizona and Nevada Journal of the Arizona-shy‐Nevada Academy of Science 2187-shy‐97

Minckley13 W L13 198313 Status of the razorback13 sucker13 Xyrauchen texanus (Abbot)13 in13 thelower Colorado River basin13 The Southwestern13 Naturalist13 28(2) 165-shy‐187

Minckley13 W L13 199113 Native fished of the Grand Canyon13 region an obituary13 Pages 124-shy‐177 in Colorado River ecology and dam13 management National Academy PressWashington13 DC

Minckley13 C13 O and M LaBarbara13 199913 Report13 on13 native fish grow-shy‐out facilities13 at Cibolaand Imperial National Wildlife Refuges 1993-shy‐199513 US Fish and13 Wildlife Service13 Parker Fishery Resources Office Parker Arizona

Modde13 T13 199613 Juvenile razorback sucker (Xyrauchen texanus) in a managed wetlandadjacent13 to the Green13 River13 Great13 Basin13 Naturalist13 56375-shy‐376

Modde T KP Burnham and E J Wick 1996 Population status of the razorback sucker13 inthe middle Green River (USA) Conservation13 biology 10 110-shy‐119

Modde13 T13 and G13 B Haines13 200513 Survival13 and growth of stocked razorback13 sucker andbonytail in multiple floodplain wetlands of the middle Green River under resetconditions13 Final report prepared for Upper Colorado13 River13 Basin RecoveryImplimentation Program US Fish and Wildlife Service Vernal 66 pp

54

13

Modde T Z H Bowen and D C Kitcheyan 2005 Spatial and temporal use of a spawning13 site in the middle Green River by wild hatchery-shy‐reared13 razorback suckers13 Transactions of the American Fisheries Society 134937-shy‐944

Mueller13 G13 199213 The native fish work13 group13 -shy‐ a multiagency endeavor to improve thestatus of the razorback sucker in Lake Mohave AZ-shy‐NV13 Proceedings of the DesertFishes Council 2369

Mueller G 1995 A program13 for maintaining the razorback sucker in Lake MohaveAmerican Fisheries Society Symposium 15127-shy‐135

Mueller13 G13 200613 Ecology of the bonytail13 and razorback13 sucker and the role of offchannelhabitats13 in their13 recovery Scientific13 investigations13 report 2006-shy‐5065 US GeologicalSurvey13 Denver

Mueller G and E Wick 1998 Testing of golf course ponds at Page Arizona for suitability13 as grow-shy‐out facility for razorback sucker using surplus fish from13 Ouray NationalFish Hatchery National Park Service US Fish and13 Wildlife13 Service and UtahDivision of Wildlife13 Resources 28 pages

Mueller13 G13 and T13 Burke13 200513 Survival13 of young13 razorback13 sucker (Xyrauchen texanus) inrelation to13 stocking rates13 (fishha)13 and13 in the presence13 or absence13 of predatorcommunities in Lake Mohave Arizona-shy‐Nevada13 Pages13 155-shy‐16313 in Proceedings of two13 symposia restoring native fish to the lower Colorado River interaction13 of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 Nevada US Fish and Wildlife13 Service Southwest Region Albuquerque New Mexico

Mueller13 G13 J13 Carpenter13 and P13 C13 Marsh13 200413 Cibola13 High Levee Pond annual report 2004US Geological Survey Fort Collins13 Science Center13 Colorado13 and Arizona StateUniversity Tempe 23 pages

Nesler T P K Christopherson J M Hudson C W McAda F Pfeifer and T E Czapla 2003An integrated stocking plan for razorback sucker bonytail and Colorado13 pikeminnow for the Upper Colorado River Endangered Fish Recovery ProgramAddendum13 to State Stocking Plans Upper Colorado River Basin Recovery13 Implementation Program 12 pp

Papoulias13 D and W13 L Minckley13 1992 Effects13 of foo availability13 on survival and growth13 of larval razorback suckers13 in ponds Transactions of the American Fisheries Society121340-shy‐355

Paukert13 C P D L Ward13 P J Sponholtz13 and K13 D Hilwig13 Effects13 of repeated hoopnetting13 on bonytail chub13 Journal of Freshwater13 Ecology13 20(4) 649-shy‐653

Pfeifer F M13 C Baker13 and M13 Montagne13 199913 Propagation13 facilities13 in the13 Grand Valley13 (24 Road13 Hatchery13 Horsethief13 Ponds and13 grow-shy‐out ponds) for captive rearing of

55

13

endangered13 fishes for the13 Upper Colorado13 River Basin13 Colorado13 River Recovery13 Program FY 99 annual project report Project No 29a13 US Fish and Wildlife Service13 Grand13 Junction13 5pp

Pfeifer F S Seversen and M Montagne 2003 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2003 annual reportProject No 29b13 US Fish and Wildlife13 Service Vernal13 4pp

Rabago-shy‐Castro J L Sanchez13 J G Perez-shy‐Castaneda R and13 Gonzalez-shy‐Gonzlez A 2006Effects of the prophylactic use of Romet-shy‐3013 and13 copper13 sulfate13 on growth13 condition13 and feeding13 indicies in13 channel13 catfish (Ictalurus punctatus) Aquaculture 253 343-shy‐349

Reinitz GL L E Orme and F N Hitzel 1979 Variations of body compositio and growth13 among strains of rainbow trout Transactions of the American Fisheries Society 108204-shy‐207

Ruppert13 J13 B P B Holden13 and P D Abate 1999 Age estimation and growth of razorbacksucker13 Xyrauchen texanus in Lake13 Mead Nevada Proceedings13 of the Desert FishesCouncil 3040

Schnoor K D and J Logan 2002 Operation and maintenance of JW Mumma nativeaquatic13 species restoration facility Colorado Colorado River Recovery Program FY2002 annual project report13 Project No 29d Colorado13 Division of Wildlife Alamosa3pp

Salisbury13 L13 1998 Factors13 affecting razorback13 sucker growth13 in Lake13 Mohave backwaters13 MS Thesis13 Unviersity13 of Nevada13 Las13 Vegas

Schooley J13 D13 and P C13 Marsh13 2007 Stocking of endangerdd13 razorback13 suckers13 in thelower Colorado River Basin13 over three decades 1974-shy‐2004 North American Journalof Fisheries Management 27 43-shy‐51

Severson S H H M Tyus and G B Haines 1992 An evaluation of feeds for raisingrazorback sucker Xyrauchen texanus Journal of Applied Aquaculture 155-shy‐65

Toney D P 1974 Observations13 on the13 propagation13 and13 rearing13 of two13 endangered species13 in a hatchery environment Proceedings of the Annual Conference of the Western13 Association of State Game and Fish Commissions 54 252-shy‐259

Tyus H M13 1998 Razorback sucker13 (Xyrauchen texanus) recovery plan13 University13 ofColorado Center for Limnology Boulder13 76 pages

Tyus H M13 and13 S H Severson 1990 Growth13 and13 survival of larval razorback suckers fedfive formulated diets The Progressive Fish Culturist 52197-shy‐200

56

13

Ulibarri M E 2003 Annual report fiscal year 2001 Dexter National Fish Hatchery13 andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 26 pages

Ulibarri M E 2003 Annual report fiscal year 2002 Dexter National Fish Hatchery andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 59 pages

USBR 2006 Lower13 Colorado13 River Multi-shy‐Species Conservation Program final fishaugmentation plan Boulder City 19 pp

USFWS 2002 Razorback sucker (Xyraouchen texanus) recovery goals Amendment andsupplement to the Razorback Sucker Recovery Plan13 US Fish and Wildlife Service13 Region 6 Denver13 Colorado

USFWS 1999 Annual report 1999 Ouray National Fish Hatchery Vernal 25pp

USFWS 2004 Management plan for the big-shy‐river13 fishes of the13 lower13 Colorado13 river basinamendment and supplement to the bonytail humpback chub Coloradopikeminnow and razorback sucker recovery plans

USFWS13 2005 Station13 profile13 of the13 Dexter13 National Fish Hatchery13 and Technology CenterUS Fish and Wildlife13 Service Dexter

Valdez R A P G Mangan R Smith and B Nilson 1982 Upper Colorado River fisheriesinvestigations13 inW H Miller J J Valentine D L Archer H M Tyus R A Valdezand L13 Kaeding13 editors13 Colorado River Fishery13 Project13 Part 2 Field13 investigations13 US Bureau of Reclamation Salt Lake City Utah

WBNFH 2004 Culture methods of the endangered razorback sucker Xyrauchen texanusUS Fish and Wildlife13 Service Willow Beach National Fish Hatchery13 8 pp

Ward D 2008 Effects of disease treatments on growth of razorback sucker ReportSubmitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 Inpartial fulfillment of work task C10 agreement number 06FG30039

Ward13 D13 M Childs and W Persons 2007 Factors13 affecting13 growth13 of razorback sucker13 (Xyrauchen texanus) in captivity Literature review and knowledge assessmentReport Submitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 In partial fulfillment of work task C10 agreement number 06FG30039

57

Appendices

Appendix 1 Survey Questions Survey of Razorback Sucker Culture in the

Southwestern United States

The enclosed survey is being distributed by the Arizona Game and Fish Department to razorback sucker culture facilities throughout

the Southwestern United States The purpose of this survey is to consolidate information regarding culture of this species so that

appropriate facility improvements can be considered for Bubbling Ponds Hatchery in Arizona Specifically we wish to increase

growth rate and production efficiency at the hatchery Information gathered in this survey will be summarized in a final report to US

Bureau of Reclamation in Boulder City NV and disseminated to all facilities that participate in the survey A workshop to discuss

the findings of this study as well as to share general information concerning razorback sucker culture will be organized by the

Arizona Game and Fish Department at the conclusion of this study and all participants will be invited

Thank you for taking the time to fill out this survey Please contact Mike Childs if you have questions or would like to discuss the

survey

Mike Childs

mchildssedonanet

(928) 639-1346

(928) 634-1279

Facility_____________________________________ Date___________________

Contact Phone _____________________________

ContactPerson_______________________________

Contact Email _______________________________

1 Water quality ranges at this culture facility

Season

Spring (Mar-May) Summer (Jun-Aug) Fall (Sept-Nov) Winter (Dec-Feb)

Temperature (C)

PH

DO (mgL)

PO4 (mgL)

TDS (mgL)

Hardness (mgL)

CaCO3

Pathogens

37

13

Effect of Ich on razorback sucker growth rates

Seventy-shy‐four13 tagged13 razorback suckers13 were13 recovered from13 Pond 8 on September

15 2010 These fish had13 been13 in the pond for 4 months and experienced a growth rate of

032 mmday or 97 mmmonth (Figure13 11)13 This growth13 rate13 is significantly higher (p =

005 two sample t-shy‐test) than the mean growth rate for the same group13 of tagged fish after

Ich detection (022 mmday or 65 mmmonth) and significantly higher than any other

individual growth13 rates13 observed13 to13 date13 at Bubbling13 Ponds Hatchery13 (Figure13 11)13 If this13

growth13 rate13 were13 extended throughout13 the entire13 year13 fish on average from13 Ich-shy‐free13 ponds13

would be 16 mm longer than fish from13 ponds infested with Ich Studies conducted at

Bubbling Ponds hatchery in 2008 (Ward 2008) did not reveal any effects of the treatment

chemicals on razorback sucker growth rates so it13 is likely that13 the parasite outbreaks

themselves are causing reducing growth rates rather than the chemicals used to treat the

parasites13

Conclusions

Our results suggest that under typical hatchery operations (maximizing number of

fish produced)13 the growth13 rate13 of razorback13 suckers13 is relatively13 consistent at Bubbling13

Ponds hatchery13 at 02-shy‐03 mmday (6-shy‐9 mmmonth)13 but is lower than growth13 rates13 at

other13 facilities (02 ndash 18 mmday Ward et al 2007)13 This growth13 rate13 has13 been13 constant in

both lined and unlined ponds and at all fish densities we were able to measure To achieve13

growth13 rates13 substantially higher than this will likely require13 significant changes in rearing

practices that may not be practical in order to reach numerical production13 goals

Temperature is a key variable in fish growth but seasonal growth patterns

described13 above13 (Figure13 5) demonstrate that water temperatures are high enough in

winter to maintain razorback growth Differences in water temperature by season

currently13 do not fluctuate more than 10degC at Bubbling Ponds because of the continuous

supply of water flowing through each pond (approx 225 gallonsmin) These high water

flows appear to keep pond temperatures within the thermal preference13 for razorback

suckers13 (1213 -shy‐ 28 degC Bulkley and Pimentel 1983) throughout the entire year with

temperatures rarely dropping13 below 16deg13 C (Figures 513 6)13

47

13

Fish density is another key variable in fish growth and though the number of fish in

a pond during our study ranged from13 3000 to 700013 fish we13 did not find any13 correlation13

between13 density and growth rate13 This might yield two conclusions First13 razorback

growth13 may be changed equally13 by13 densities13 at the13 hatchery13 (ie13 a density13 of 3000 fish in a

pond is as stressful13 for razorbacks as a density13 of 7000 fish) An alternative is that other

factors13 such as disease outbreaks have13 stronger13 control over fish growth13 than13 density13

Fish density13 would13 have13 to13 be13 experimentally manipulated to test13 this13 and hatchery

operations (producing the maximum13 number of fish) prevented our manipulating density13

in ponds for this13 work The trouble with manipulating density demonstrates the difficulties

associated with changing13 hatchery13 practices experimenting with density would have

prevented BPH from13 meeting13 production13 goals Given that the stocking of smaller

razorbacks has met with very little success perhaps BPH goals could be changed from13

producing 12000 fish at 300+ mm per year to a smaller number of very large fish each

year Growing13 fewer13 larger13 fish could potentially be accomplished in the same time frame

as more smaller fish but a better understanding of how density alters growth rate would

be required to be confident13 of this

The very slow growth13 in the13 earthen13 unlined13 Pond 1 lower13 was very surprising We13

had13 anticipated13 that the13 diversified diet13 cover and13 other13 habitat features13 provided by13

unlined ponds would yield dramatically increased growth rates However these traits were

not enough to offset high fish densities and in fact the unlined pond in our study13 suffered

mortality to bring densities down to that observed normally in lined ponds

Our data13 suggest13 that razorbacks13 sucker13 growth13 rates13 are13 higher in lined13 ponds13

However we13 think the reasons13 for the13 very slow growth we observed13 in the13 unlined13 pond13

in our study13 is instead13 linked13 to13 the13 usage13 of Pond 1 lower13 during13 the13 study13 rather13 than13

intrinsic13 slow growth13 in earthen13 ponds First the pond was at extremely high density for at

least part of the study The volume of Pond 1 lower has not been estimated but hatchery

managers suggest 1500-shy‐2000 fish is an appropriate number of individuals so this pond

was at a very high density for much of the experiment Second dissolved oxygen is often

very low in the13 large13 earthen13 ponds during the heat of summer much lower than that of

lined ponds This will both limit the number of fish that can survive in the pond and almost

certainly13 increases stress13 of these13 fish potentially13 reducing growth13 The DO crashes also13

48

13

limit the amount of feed hatchery managers can give fish in these ponds sometimes for

days or weeks at a time which further reduces growth during warm13 weather

Our data13 suggests that13 growth rates at the Bubbling13 Ponds Fish Hatchery are likely

as high as possible given13 the pond densities required to meet production goals and the Ich-shy‐

infested water that feeds the facility Sorting practices are successful in helping as many

fish as possible reach stocking length as fast as possible Unlined ponds may be able to

grow13 large13 fish at low13 densities13 but whatever factors allow13 for that13 growth are not13 able to

overcome high fish density The removal of invasive13 fis that act as13 a host for the13 parasite13

Ich fish from13 the Bubbling13 Ponds spring13 allowed the highest13 growth rate at 032 mmday13

(96 mmmonth) but that growth rate decreased again as Ich re-shy‐infested13 the13 hatchery13

Consistently13 achieving13 growth13 rates13 as high or substantially13 higher than13 this13 will likely13

require13 significant changes in rearing practices that may not be practical in order to13 reach13

numerical production13 goals

Two major changes that might result in higher growth rates are substantially

reducing fish density and modifying the way spring water is delivered to the facility (via

either repeated chemical treatments or enclosed concrete water diversions) to eliminate

Ich from13 the hatchery source water Other potential changes not address by our work

include13 flow-shy‐training razorbacks much previous literature including MSCP-shy‐funded13 work

on razorback suckers13 suggests13 that fish growing13 in flowing water will grow13 faster than fish

in still water (Jorgensen and Jobling 1994) Furthermore there are a wide variety of

potential benefits associated with growing13 fish13 in flowing13 water in addition13 to increased

growth13 rates13 (Davidson13 199713 Castro13 et al13 2011) Another option13 for increasing13 growth13

rates13 include13 changing to13 intensive13 culture13 in large circular13 tanks

Finally given that the stocking of smaller razorbacks has met with very little

success13 perhaps13 BPH13 goals13 could13 be13 changed from13 producing 12000 fish at 300+ mm per

year to a smaller number of very large fish each year Growing fewer larger fish could

potentially be accomplished in the same time frame as more smaller fish but a better

understanding13 of how density13 alters growth13 rate13 would13 be13 required to13 be13 confident of this

49

13

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower13 Colorado13 River Multi-shy‐Species13

Conservation Program13 (LCRMSCP) under Work Task C10 We13 thank Ty Wolters13 Tom13

Burke13 and Eric13 Volkman for their support of this research and Frank Agygos and Dave

Billingsly13 of the Bubbling13 Ponds Fish Hatchery13 for their willingness to participate in13 this

research13 and13 for their technical assistance We also thank the LCRMSCP fish group from13

Boulder City13 NV for their assistance with harvesting13 ponds and tagging13 fish13

50

13

Literature13 CitedAnders P J 1998 Conservation aquaculture and endangered species can objective science13

prevail13 over risk13 anxiety Fisheries 23(11) 28-shy‐31

Anderson R O and R M Nuemann 1996 Length weight and associated structural indicesPages 447 ndash 482 in B R Murphy13 and D13 W Willis13 editors13 Fisheries techniques13 2ndedtion American Fisheries13 Society13 Bethesda13 Maryland

Bain M B J T Finn and H E Brooks 1988 Streamflow regulation and fish communitystructure13 Ecology13 69382-shy‐392

Bays J H Zarbock R Whitman and T Murphy 2005 Conceptual design and managementof native13 fish refugia on the13 lower13 Colorado13 River In13 CL Spring13 and13 S Leoneditors Proceedings of two symposia Restoring native fish to the lower ColoradoRiver13 interactions13 of native and non-shy‐native13 fishes 13ndash1413 July13 1999 Las13 Vegas13 Nevada13 Restoring13 natural function within a modified riverine environment thelower Colorado River13 8ndash913 July13 1998 U S Fish and13 Wildlife13 Service Southwestern13 Region Albuquerque New Mexico Pages 167-shy‐177

Bertalanffy L Von 1957 Quantitative laws in metabolism13 and growth13 Q Rev Biology 32217 ndash 231

Bingham T B Scheer and C McAda 2003 Propagation facilities in Grand Valley (24 RoadHatchery Horsethief13 Ponds and13 grow-shy‐out ponds) for captive13 rearing13 ofendangered13 fishes for the13 upper13 Colorado13 River basin13 Colorado River RecoveryProgram FY2003 annual project report13 US Fish and13 Wildlife13 Service GrandJunction13 4pp

Birchell G J and K Christopherson 2004 Survival growth and recruitment of larval andjuvenile razorback13 sucker (Xyrauchen texanus) introduced13 into13 floodplain13 depressions13 of the13 Green River Utah13 Final report13 Upper13 Colorado13 RiverEndangered Fish Recovery Program13 Project No C-shy‐6RZ Publication Number 04-shy‐1513 Utah13 Division of Wildlife13 Resources Salt Lake13 City13 Utah13 67 pages

Brannon E L 1993 The perpetual oversight of hatchery programs Fishery Research 1819-shy‐27

Brett J R 1979 Environmental Factors and growth pages 599-shy‐67513 InW S Hoar13 D13 J13 Randall and J R Brett (eds) Fish Physiology Volume 8 Bioenergetics and GrowthAcademic Press New York

Brooks J E 1986 Annual reintroduction and monitoring report for razorback suckerXyrauchen texanus in the Gila River Basin Arizona 1985 US Fish and WildlifeService13 Offices of Endangered13 Species and Fishery13 Resources Albuquerque 23 pp

51

13

Brunson13 R E and K D13 Christopherson13 200513 Larval13 razorback13 sucker and bonytailsurvival and13 growth13 in the13 presence13 of nonnative13 fish in the13 Baeser13 floodplainwetland of the middle Green River Final report prepared for Upper13 Colorado RiverBasin Endangered Fish Recovery Program Project No C-shy‐6-shy‐rz-shy‐bt Publication13 No 05-shy‐26 Utah13 Division of Wildlife13 Resources13 Vernal13 32 pp

Bulkley R V and R Pimentel 1983 Temperature preference and avoidance by adultrazorback suckers Transactions of the American Fisheries Society 112601-shy‐607

Burke13 T13 199513 Rearing13 wild razorback13 sucker larvae in13 lake-shy‐side13 backwaters13 LakeMohave ArizonaNevada Proceedings of the Desert Fishes Council 2635

Busacker G P I R Adelman and E M Goolish13 199013 Growth13 Pages 363 ndash 387 in C BSchreck and p B Moyle editors Methods for fish biology American FisheriesSociety Bethesda Maryland

Castro V B Grisdale-shy‐Helland S J Helland T Kristensen S M Jorgensen J Helgrud13 GClaireaux A P Farrell A Krasnov and H Takle 2011 Aerobic training stimulatesgrowth and promotes disease resistance in Atlantic salmon (Salmo salar)Comparative Biochemistry and Physiology -shy‐ Part A Molecular amp IntegrativePhysiology13 160(2) 278-shy‐290

Czapla T E 2002 Facilities plan for the production of endangered fishes to meet statestocking13 plans13 as13 part of the13 Upper13 Colorado13 River Endangered13 Fish RecoveryProgram Upper Colorado River Basin Recovery Implementation Program US Fishand Wildlife Service13 Denver13 9 pp

Davidson W 1997 The effects13 of exercise13 training on teleost fish a review of recentliterature Comput Biochem Physiol 117A67ndash75

Figiel Jr C R 2005 Annual report fiscal year 2004 Willow Beach National13 Fish HatcheryUS Fish and Wildlife13 Service Willow Beach 17 pp

Figiel Jr C R M E Ulibarri G Carmichael J Seals and J N Hanson 2005 Intensive13 fish13 culture of warmwater native fishes at a coldwater fish hatchery Pages 164-shy‐16613 inProceedings of two symposia restoring native fish to the lower Colorado13 River13 interaction13 of native13 and13 non-shy‐native13 fishes July13 13-shy‐1413 1999 Las Vegas Nevada USFish and Wildlife Service Southwest Region Albuquerque New Mexico

Gerking13 S D 1978 Ecology of freshwater fish13 production13 Halstead Press13 New13 York

Gustafson W and Q Bradwisch 2000 Wahweap operation and maintenance -shy‐-shy‐ UtahColorado River Recovery Program FY 2000 annual project report Project No 29cUtah13 Division of Wildlife13 Resources Page AZ 3pp

52

13

Hamman R L 1985 Induced spawning of hatchery-shy‐reared13 razorback sucker ProgressivFish Culturist 47(3) 187-shy‐189

Hanson J N 1996 Annual report fiscal year 1996 Willow Beach National Fish HatcheryUS Fish and Wildlife Service13 Willow Beach 9pp

Irving D S Seversen and M Montagne 2004 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2004 annual project13 report Report No 29b US Fish and13 Wildlife13 Service Vernal 3pp

Jorgensen E H and13 M Jobling 1994 Feeding and13 growth13 of exercised13 and13 unexercised13 juvenile Atlantic salmon in freshwater and performance after transfer to seawaterAquaculture International 2 154-shy‐164

Kaeding L R and D B Osmundson 198913 Colorado13 Squawfish13 and13 razorback sucker grow-shy‐out pond studies as part of conservation measures for the green mountain andRuedi reservoir water sales Final report for agreement number 6-shy‐AA-shy‐60-shy‐00150

Koebele13 B P13 198513 Growth and the size hierarchy effect an experimental assessment ofthree proposed mechanisms activity differences disproportional food acquisition13 pysiological stress Environmental Biology of Fishes 12 181-shy‐188

Kretschmann A E and L L Leslie 2006 Razorback sucker (Xyrauchen texanus) status13 reproduction and recruitment in Senator Wash Reservoir CA Final Report13 to USBurea of Reclamation Cooperative Agreement No 00-shy‐FG-shy‐34-shy‐ 0009 p 32 ArizonaGame and Fish Department Phoenix

Marsh13 P13 C13 1987a13 Digestive tract13 contents13 of adult razorback suckers13 in Lake13 MohaveArizona-shy‐Nevada Transactions of the American Fisheries Society 116117-shy‐119

Marsh P C 1987b Native fishes at Buenos Aires National Wildlife Refuge and ArizonaState University Research Park Arizona opportunities for management researchand public13 education13 on13 endangered species13 Proceedings of the Desert13 FishesCouncil 1967-shy‐78

Marsh P C 1994 Rearing native Colorado River fishes in golf course ponds Arizona StateUniversity Tempe 22 + pages

Marsh13 P13 C13 200013 Fish population13 status and evaluation13 in13 the Cibola13 High Levee PondFinal report agreement number 99-shy‐FG-shy‐30-shy‐00051 US Bureau of ReclamationBoulder City13 Nevada13 20 pages

Marsh P C and C A Pacey 1998 Growth of wild adult razorback suckers13 in Lake13 Mohave13 Arizona-shy‐Nevada13 Final report13 US Bureau of Reclamation Boulder City Nevada 25pages + appendices

53

13

Marsh P C B R Kesner and C A Pacey 2005 Repatriation as s management strategy13 to13 conserve a critically13 imperiled fish species North American Journal of FisheriesManagement 25 547-shy‐556

Marsh P C and C A Pacey 2005 Immiscibility of native and non-shy‐native13 fishes Pages 59-shy‐63 inMJ13 Brouder13 CL13 Springer13 and CS13 Leon13 editors13 Proceedings of two13 symposia Restoring native fish to the lower Colorado River interactions of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 NV and13 Restoring natural13 function within a modified riverine environment the lower Colorado River13 July13 8-shy‐913 1998 Las Vegas NV US Fish and13 Wildlife13 Service Southwest Region AlbuquerqueNew Mexico

Marsh13 P13 C13 and J13 E Brooks13 198913 Predation13 by ictalurid catfishes as a deterrent13 toreestablishment of hatchery-shy‐reared13 razorback sucker The Southwestern Naturalist34188-shy‐195

Matthews R A 2005 Ichthyopthirus multifiliis Fouquet and Ichthyopthirosis infreshwater13 teleosts13 Pages13 159-shy‐218 in Advances in Parasitology volume 59 J RBaker R Muller D Rollinson (eds) Academic Press

McCarthy13 M S and W L Minckley 1987 Age estimation for razorback sucker (PiscesCatostomidae) from13 Lake Mohave Arizona and Nevada Journal of the Arizona-shy‐Nevada Academy of Science 2187-shy‐97

Minckley13 W L13 198313 Status of the razorback13 sucker13 Xyrauchen texanus (Abbot)13 in13 thelower Colorado River basin13 The Southwestern13 Naturalist13 28(2) 165-shy‐187

Minckley13 W L13 199113 Native fished of the Grand Canyon13 region an obituary13 Pages 124-shy‐177 in Colorado River ecology and dam13 management National Academy PressWashington13 DC

Minckley13 C13 O and M LaBarbara13 199913 Report13 on13 native fish grow-shy‐out facilities13 at Cibolaand Imperial National Wildlife Refuges 1993-shy‐199513 US Fish and13 Wildlife Service13 Parker Fishery Resources Office Parker Arizona

Modde13 T13 199613 Juvenile razorback sucker (Xyrauchen texanus) in a managed wetlandadjacent13 to the Green13 River13 Great13 Basin13 Naturalist13 56375-shy‐376

Modde T KP Burnham and E J Wick 1996 Population status of the razorback sucker13 inthe middle Green River (USA) Conservation13 biology 10 110-shy‐119

Modde13 T13 and G13 B Haines13 200513 Survival13 and growth of stocked razorback13 sucker andbonytail in multiple floodplain wetlands of the middle Green River under resetconditions13 Final report prepared for Upper Colorado13 River13 Basin RecoveryImplimentation Program US Fish and Wildlife Service Vernal 66 pp

54

13

Modde T Z H Bowen and D C Kitcheyan 2005 Spatial and temporal use of a spawning13 site in the middle Green River by wild hatchery-shy‐reared13 razorback suckers13 Transactions of the American Fisheries Society 134937-shy‐944

Mueller13 G13 199213 The native fish work13 group13 -shy‐ a multiagency endeavor to improve thestatus of the razorback sucker in Lake Mohave AZ-shy‐NV13 Proceedings of the DesertFishes Council 2369

Mueller G 1995 A program13 for maintaining the razorback sucker in Lake MohaveAmerican Fisheries Society Symposium 15127-shy‐135

Mueller13 G13 200613 Ecology of the bonytail13 and razorback13 sucker and the role of offchannelhabitats13 in their13 recovery Scientific13 investigations13 report 2006-shy‐5065 US GeologicalSurvey13 Denver

Mueller G and E Wick 1998 Testing of golf course ponds at Page Arizona for suitability13 as grow-shy‐out facility for razorback sucker using surplus fish from13 Ouray NationalFish Hatchery National Park Service US Fish and13 Wildlife13 Service and UtahDivision of Wildlife13 Resources 28 pages

Mueller13 G13 and T13 Burke13 200513 Survival13 of young13 razorback13 sucker (Xyrauchen texanus) inrelation to13 stocking rates13 (fishha)13 and13 in the presence13 or absence13 of predatorcommunities in Lake Mohave Arizona-shy‐Nevada13 Pages13 155-shy‐16313 in Proceedings of two13 symposia restoring native fish to the lower Colorado River interaction13 of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 Nevada US Fish and Wildlife13 Service Southwest Region Albuquerque New Mexico

Mueller13 G13 J13 Carpenter13 and P13 C13 Marsh13 200413 Cibola13 High Levee Pond annual report 2004US Geological Survey Fort Collins13 Science Center13 Colorado13 and Arizona StateUniversity Tempe 23 pages

Nesler T P K Christopherson J M Hudson C W McAda F Pfeifer and T E Czapla 2003An integrated stocking plan for razorback sucker bonytail and Colorado13 pikeminnow for the Upper Colorado River Endangered Fish Recovery ProgramAddendum13 to State Stocking Plans Upper Colorado River Basin Recovery13 Implementation Program 12 pp

Papoulias13 D and W13 L Minckley13 1992 Effects13 of foo availability13 on survival and growth13 of larval razorback suckers13 in ponds Transactions of the American Fisheries Society121340-shy‐355

Paukert13 C P D L Ward13 P J Sponholtz13 and K13 D Hilwig13 Effects13 of repeated hoopnetting13 on bonytail chub13 Journal of Freshwater13 Ecology13 20(4) 649-shy‐653

Pfeifer F M13 C Baker13 and M13 Montagne13 199913 Propagation13 facilities13 in the13 Grand Valley13 (24 Road13 Hatchery13 Horsethief13 Ponds and13 grow-shy‐out ponds) for captive rearing of

55

13

endangered13 fishes for the13 Upper Colorado13 River Basin13 Colorado13 River Recovery13 Program FY 99 annual project report Project No 29a13 US Fish and Wildlife Service13 Grand13 Junction13 5pp

Pfeifer F S Seversen and M Montagne 2003 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2003 annual reportProject No 29b13 US Fish and Wildlife13 Service Vernal13 4pp

Rabago-shy‐Castro J L Sanchez13 J G Perez-shy‐Castaneda R and13 Gonzalez-shy‐Gonzlez A 2006Effects of the prophylactic use of Romet-shy‐3013 and13 copper13 sulfate13 on growth13 condition13 and feeding13 indicies in13 channel13 catfish (Ictalurus punctatus) Aquaculture 253 343-shy‐349

Reinitz GL L E Orme and F N Hitzel 1979 Variations of body compositio and growth13 among strains of rainbow trout Transactions of the American Fisheries Society 108204-shy‐207

Ruppert13 J13 B P B Holden13 and P D Abate 1999 Age estimation and growth of razorbacksucker13 Xyrauchen texanus in Lake13 Mead Nevada Proceedings13 of the Desert FishesCouncil 3040

Schnoor K D and J Logan 2002 Operation and maintenance of JW Mumma nativeaquatic13 species restoration facility Colorado Colorado River Recovery Program FY2002 annual project report13 Project No 29d Colorado13 Division of Wildlife Alamosa3pp

Salisbury13 L13 1998 Factors13 affecting razorback13 sucker growth13 in Lake13 Mohave backwaters13 MS Thesis13 Unviersity13 of Nevada13 Las13 Vegas

Schooley J13 D13 and P C13 Marsh13 2007 Stocking of endangerdd13 razorback13 suckers13 in thelower Colorado River Basin13 over three decades 1974-shy‐2004 North American Journalof Fisheries Management 27 43-shy‐51

Severson S H H M Tyus and G B Haines 1992 An evaluation of feeds for raisingrazorback sucker Xyrauchen texanus Journal of Applied Aquaculture 155-shy‐65

Toney D P 1974 Observations13 on the13 propagation13 and13 rearing13 of two13 endangered species13 in a hatchery environment Proceedings of the Annual Conference of the Western13 Association of State Game and Fish Commissions 54 252-shy‐259

Tyus H M13 1998 Razorback sucker13 (Xyrauchen texanus) recovery plan13 University13 ofColorado Center for Limnology Boulder13 76 pages

Tyus H M13 and13 S H Severson 1990 Growth13 and13 survival of larval razorback suckers fedfive formulated diets The Progressive Fish Culturist 52197-shy‐200

56

13

Ulibarri M E 2003 Annual report fiscal year 2001 Dexter National Fish Hatchery13 andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 26 pages

Ulibarri M E 2003 Annual report fiscal year 2002 Dexter National Fish Hatchery andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 59 pages

USBR 2006 Lower13 Colorado13 River Multi-shy‐Species Conservation Program final fishaugmentation plan Boulder City 19 pp

USFWS 2002 Razorback sucker (Xyraouchen texanus) recovery goals Amendment andsupplement to the Razorback Sucker Recovery Plan13 US Fish and Wildlife Service13 Region 6 Denver13 Colorado

USFWS 1999 Annual report 1999 Ouray National Fish Hatchery Vernal 25pp

USFWS 2004 Management plan for the big-shy‐river13 fishes of the13 lower13 Colorado13 river basinamendment and supplement to the bonytail humpback chub Coloradopikeminnow and razorback sucker recovery plans

USFWS13 2005 Station13 profile13 of the13 Dexter13 National Fish Hatchery13 and Technology CenterUS Fish and Wildlife13 Service Dexter

Valdez R A P G Mangan R Smith and B Nilson 1982 Upper Colorado River fisheriesinvestigations13 inW H Miller J J Valentine D L Archer H M Tyus R A Valdezand L13 Kaeding13 editors13 Colorado River Fishery13 Project13 Part 2 Field13 investigations13 US Bureau of Reclamation Salt Lake City Utah

WBNFH 2004 Culture methods of the endangered razorback sucker Xyrauchen texanusUS Fish and Wildlife13 Service Willow Beach National Fish Hatchery13 8 pp

Ward D 2008 Effects of disease treatments on growth of razorback sucker ReportSubmitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 Inpartial fulfillment of work task C10 agreement number 06FG30039

Ward13 D13 M Childs and W Persons 2007 Factors13 affecting13 growth13 of razorback sucker13 (Xyrauchen texanus) in captivity Literature review and knowledge assessmentReport Submitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 In partial fulfillment of work task C10 agreement number 06FG30039

57

Appendices

Appendix 1 Survey Questions Survey of Razorback Sucker Culture in the

Southwestern United States

The enclosed survey is being distributed by the Arizona Game and Fish Department to razorback sucker culture facilities throughout

the Southwestern United States The purpose of this survey is to consolidate information regarding culture of this species so that

appropriate facility improvements can be considered for Bubbling Ponds Hatchery in Arizona Specifically we wish to increase

growth rate and production efficiency at the hatchery Information gathered in this survey will be summarized in a final report to US

Bureau of Reclamation in Boulder City NV and disseminated to all facilities that participate in the survey A workshop to discuss

the findings of this study as well as to share general information concerning razorback sucker culture will be organized by the

Arizona Game and Fish Department at the conclusion of this study and all participants will be invited

Thank you for taking the time to fill out this survey Please contact Mike Childs if you have questions or would like to discuss the

survey

Mike Childs

mchildssedonanet

(928) 639-1346

(928) 634-1279

Facility_____________________________________ Date___________________

Contact Phone _____________________________

ContactPerson_______________________________

Contact Email _______________________________

1 Water quality ranges at this culture facility

Season

Spring (Mar-May) Summer (Jun-Aug) Fall (Sept-Nov) Winter (Dec-Feb)

Temperature (C)

PH

DO (mgL)

PO4 (mgL)

TDS (mgL)

Hardness (mgL)

CaCO3

Pathogens

37

13

Fish density is another key variable in fish growth and though the number of fish in

a pond during our study ranged from13 3000 to 700013 fish we13 did not find any13 correlation13

between13 density and growth rate13 This might yield two conclusions First13 razorback

growth13 may be changed equally13 by13 densities13 at the13 hatchery13 (ie13 a density13 of 3000 fish in a

pond is as stressful13 for razorbacks as a density13 of 7000 fish) An alternative is that other

factors13 such as disease outbreaks have13 stronger13 control over fish growth13 than13 density13

Fish density13 would13 have13 to13 be13 experimentally manipulated to test13 this13 and hatchery

operations (producing the maximum13 number of fish) prevented our manipulating density13

in ponds for this13 work The trouble with manipulating density demonstrates the difficulties

associated with changing13 hatchery13 practices experimenting with density would have

prevented BPH from13 meeting13 production13 goals Given that the stocking of smaller

razorbacks has met with very little success perhaps BPH goals could be changed from13

producing 12000 fish at 300+ mm per year to a smaller number of very large fish each

year Growing13 fewer13 larger13 fish could potentially be accomplished in the same time frame

as more smaller fish but a better understanding of how density alters growth rate would

be required to be confident13 of this

The very slow growth13 in the13 earthen13 unlined13 Pond 1 lower13 was very surprising We13

had13 anticipated13 that the13 diversified diet13 cover and13 other13 habitat features13 provided by13

unlined ponds would yield dramatically increased growth rates However these traits were

not enough to offset high fish densities and in fact the unlined pond in our study13 suffered

mortality to bring densities down to that observed normally in lined ponds

Our data13 suggest13 that razorbacks13 sucker13 growth13 rates13 are13 higher in lined13 ponds13

However we13 think the reasons13 for the13 very slow growth we observed13 in the13 unlined13 pond13

in our study13 is instead13 linked13 to13 the13 usage13 of Pond 1 lower13 during13 the13 study13 rather13 than13

intrinsic13 slow growth13 in earthen13 ponds First the pond was at extremely high density for at

least part of the study The volume of Pond 1 lower has not been estimated but hatchery

managers suggest 1500-shy‐2000 fish is an appropriate number of individuals so this pond

was at a very high density for much of the experiment Second dissolved oxygen is often

very low in the13 large13 earthen13 ponds during the heat of summer much lower than that of

lined ponds This will both limit the number of fish that can survive in the pond and almost

certainly13 increases stress13 of these13 fish potentially13 reducing growth13 The DO crashes also13

48

13

limit the amount of feed hatchery managers can give fish in these ponds sometimes for

days or weeks at a time which further reduces growth during warm13 weather

Our data13 suggests that13 growth rates at the Bubbling13 Ponds Fish Hatchery are likely

as high as possible given13 the pond densities required to meet production goals and the Ich-shy‐

infested water that feeds the facility Sorting practices are successful in helping as many

fish as possible reach stocking length as fast as possible Unlined ponds may be able to

grow13 large13 fish at low13 densities13 but whatever factors allow13 for that13 growth are not13 able to

overcome high fish density The removal of invasive13 fis that act as13 a host for the13 parasite13

Ich fish from13 the Bubbling13 Ponds spring13 allowed the highest13 growth rate at 032 mmday13

(96 mmmonth) but that growth rate decreased again as Ich re-shy‐infested13 the13 hatchery13

Consistently13 achieving13 growth13 rates13 as high or substantially13 higher than13 this13 will likely13

require13 significant changes in rearing practices that may not be practical in order to13 reach13

numerical production13 goals

Two major changes that might result in higher growth rates are substantially

reducing fish density and modifying the way spring water is delivered to the facility (via

either repeated chemical treatments or enclosed concrete water diversions) to eliminate

Ich from13 the hatchery source water Other potential changes not address by our work

include13 flow-shy‐training razorbacks much previous literature including MSCP-shy‐funded13 work

on razorback suckers13 suggests13 that fish growing13 in flowing water will grow13 faster than fish

in still water (Jorgensen and Jobling 1994) Furthermore there are a wide variety of

potential benefits associated with growing13 fish13 in flowing13 water in addition13 to increased

growth13 rates13 (Davidson13 199713 Castro13 et al13 2011) Another option13 for increasing13 growth13

rates13 include13 changing to13 intensive13 culture13 in large circular13 tanks

Finally given that the stocking of smaller razorbacks has met with very little

success13 perhaps13 BPH13 goals13 could13 be13 changed from13 producing 12000 fish at 300+ mm per

year to a smaller number of very large fish each year Growing fewer larger fish could

potentially be accomplished in the same time frame as more smaller fish but a better

understanding13 of how density13 alters growth13 rate13 would13 be13 required to13 be13 confident of this

49

13

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower13 Colorado13 River Multi-shy‐Species13

Conservation Program13 (LCRMSCP) under Work Task C10 We13 thank Ty Wolters13 Tom13

Burke13 and Eric13 Volkman for their support of this research and Frank Agygos and Dave

Billingsly13 of the Bubbling13 Ponds Fish Hatchery13 for their willingness to participate in13 this

research13 and13 for their technical assistance We also thank the LCRMSCP fish group from13

Boulder City13 NV for their assistance with harvesting13 ponds and tagging13 fish13

50

13

Literature13 CitedAnders P J 1998 Conservation aquaculture and endangered species can objective science13

prevail13 over risk13 anxiety Fisheries 23(11) 28-shy‐31

Anderson R O and R M Nuemann 1996 Length weight and associated structural indicesPages 447 ndash 482 in B R Murphy13 and D13 W Willis13 editors13 Fisheries techniques13 2ndedtion American Fisheries13 Society13 Bethesda13 Maryland

Bain M B J T Finn and H E Brooks 1988 Streamflow regulation and fish communitystructure13 Ecology13 69382-shy‐392

Bays J H Zarbock R Whitman and T Murphy 2005 Conceptual design and managementof native13 fish refugia on the13 lower13 Colorado13 River In13 CL Spring13 and13 S Leoneditors Proceedings of two symposia Restoring native fish to the lower ColoradoRiver13 interactions13 of native and non-shy‐native13 fishes 13ndash1413 July13 1999 Las13 Vegas13 Nevada13 Restoring13 natural function within a modified riverine environment thelower Colorado River13 8ndash913 July13 1998 U S Fish and13 Wildlife13 Service Southwestern13 Region Albuquerque New Mexico Pages 167-shy‐177

Bertalanffy L Von 1957 Quantitative laws in metabolism13 and growth13 Q Rev Biology 32217 ndash 231

Bingham T B Scheer and C McAda 2003 Propagation facilities in Grand Valley (24 RoadHatchery Horsethief13 Ponds and13 grow-shy‐out ponds) for captive13 rearing13 ofendangered13 fishes for the13 upper13 Colorado13 River basin13 Colorado River RecoveryProgram FY2003 annual project report13 US Fish and13 Wildlife13 Service GrandJunction13 4pp

Birchell G J and K Christopherson 2004 Survival growth and recruitment of larval andjuvenile razorback13 sucker (Xyrauchen texanus) introduced13 into13 floodplain13 depressions13 of the13 Green River Utah13 Final report13 Upper13 Colorado13 RiverEndangered Fish Recovery Program13 Project No C-shy‐6RZ Publication Number 04-shy‐1513 Utah13 Division of Wildlife13 Resources Salt Lake13 City13 Utah13 67 pages

Brannon E L 1993 The perpetual oversight of hatchery programs Fishery Research 1819-shy‐27

Brett J R 1979 Environmental Factors and growth pages 599-shy‐67513 InW S Hoar13 D13 J13 Randall and J R Brett (eds) Fish Physiology Volume 8 Bioenergetics and GrowthAcademic Press New York

Brooks J E 1986 Annual reintroduction and monitoring report for razorback suckerXyrauchen texanus in the Gila River Basin Arizona 1985 US Fish and WildlifeService13 Offices of Endangered13 Species and Fishery13 Resources Albuquerque 23 pp

51

13

Brunson13 R E and K D13 Christopherson13 200513 Larval13 razorback13 sucker and bonytailsurvival and13 growth13 in the13 presence13 of nonnative13 fish in the13 Baeser13 floodplainwetland of the middle Green River Final report prepared for Upper13 Colorado RiverBasin Endangered Fish Recovery Program Project No C-shy‐6-shy‐rz-shy‐bt Publication13 No 05-shy‐26 Utah13 Division of Wildlife13 Resources13 Vernal13 32 pp

Bulkley R V and R Pimentel 1983 Temperature preference and avoidance by adultrazorback suckers Transactions of the American Fisheries Society 112601-shy‐607

Burke13 T13 199513 Rearing13 wild razorback13 sucker larvae in13 lake-shy‐side13 backwaters13 LakeMohave ArizonaNevada Proceedings of the Desert Fishes Council 2635

Busacker G P I R Adelman and E M Goolish13 199013 Growth13 Pages 363 ndash 387 in C BSchreck and p B Moyle editors Methods for fish biology American FisheriesSociety Bethesda Maryland

Castro V B Grisdale-shy‐Helland S J Helland T Kristensen S M Jorgensen J Helgrud13 GClaireaux A P Farrell A Krasnov and H Takle 2011 Aerobic training stimulatesgrowth and promotes disease resistance in Atlantic salmon (Salmo salar)Comparative Biochemistry and Physiology -shy‐ Part A Molecular amp IntegrativePhysiology13 160(2) 278-shy‐290

Czapla T E 2002 Facilities plan for the production of endangered fishes to meet statestocking13 plans13 as13 part of the13 Upper13 Colorado13 River Endangered13 Fish RecoveryProgram Upper Colorado River Basin Recovery Implementation Program US Fishand Wildlife Service13 Denver13 9 pp

Davidson W 1997 The effects13 of exercise13 training on teleost fish a review of recentliterature Comput Biochem Physiol 117A67ndash75

Figiel Jr C R 2005 Annual report fiscal year 2004 Willow Beach National13 Fish HatcheryUS Fish and Wildlife13 Service Willow Beach 17 pp

Figiel Jr C R M E Ulibarri G Carmichael J Seals and J N Hanson 2005 Intensive13 fish13 culture of warmwater native fishes at a coldwater fish hatchery Pages 164-shy‐16613 inProceedings of two symposia restoring native fish to the lower Colorado13 River13 interaction13 of native13 and13 non-shy‐native13 fishes July13 13-shy‐1413 1999 Las Vegas Nevada USFish and Wildlife Service Southwest Region Albuquerque New Mexico

Gerking13 S D 1978 Ecology of freshwater fish13 production13 Halstead Press13 New13 York

Gustafson W and Q Bradwisch 2000 Wahweap operation and maintenance -shy‐-shy‐ UtahColorado River Recovery Program FY 2000 annual project report Project No 29cUtah13 Division of Wildlife13 Resources Page AZ 3pp

52

13

Hamman R L 1985 Induced spawning of hatchery-shy‐reared13 razorback sucker ProgressivFish Culturist 47(3) 187-shy‐189

Hanson J N 1996 Annual report fiscal year 1996 Willow Beach National Fish HatcheryUS Fish and Wildlife Service13 Willow Beach 9pp

Irving D S Seversen and M Montagne 2004 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2004 annual project13 report Report No 29b US Fish and13 Wildlife13 Service Vernal 3pp

Jorgensen E H and13 M Jobling 1994 Feeding and13 growth13 of exercised13 and13 unexercised13 juvenile Atlantic salmon in freshwater and performance after transfer to seawaterAquaculture International 2 154-shy‐164

Kaeding L R and D B Osmundson 198913 Colorado13 Squawfish13 and13 razorback sucker grow-shy‐out pond studies as part of conservation measures for the green mountain andRuedi reservoir water sales Final report for agreement number 6-shy‐AA-shy‐60-shy‐00150

Koebele13 B P13 198513 Growth and the size hierarchy effect an experimental assessment ofthree proposed mechanisms activity differences disproportional food acquisition13 pysiological stress Environmental Biology of Fishes 12 181-shy‐188

Kretschmann A E and L L Leslie 2006 Razorback sucker (Xyrauchen texanus) status13 reproduction and recruitment in Senator Wash Reservoir CA Final Report13 to USBurea of Reclamation Cooperative Agreement No 00-shy‐FG-shy‐34-shy‐ 0009 p 32 ArizonaGame and Fish Department Phoenix

Marsh13 P13 C13 1987a13 Digestive tract13 contents13 of adult razorback suckers13 in Lake13 MohaveArizona-shy‐Nevada Transactions of the American Fisheries Society 116117-shy‐119

Marsh P C 1987b Native fishes at Buenos Aires National Wildlife Refuge and ArizonaState University Research Park Arizona opportunities for management researchand public13 education13 on13 endangered species13 Proceedings of the Desert13 FishesCouncil 1967-shy‐78

Marsh P C 1994 Rearing native Colorado River fishes in golf course ponds Arizona StateUniversity Tempe 22 + pages

Marsh13 P13 C13 200013 Fish population13 status and evaluation13 in13 the Cibola13 High Levee PondFinal report agreement number 99-shy‐FG-shy‐30-shy‐00051 US Bureau of ReclamationBoulder City13 Nevada13 20 pages

Marsh P C and C A Pacey 1998 Growth of wild adult razorback suckers13 in Lake13 Mohave13 Arizona-shy‐Nevada13 Final report13 US Bureau of Reclamation Boulder City Nevada 25pages + appendices

53

13

Marsh P C B R Kesner and C A Pacey 2005 Repatriation as s management strategy13 to13 conserve a critically13 imperiled fish species North American Journal of FisheriesManagement 25 547-shy‐556

Marsh P C and C A Pacey 2005 Immiscibility of native and non-shy‐native13 fishes Pages 59-shy‐63 inMJ13 Brouder13 CL13 Springer13 and CS13 Leon13 editors13 Proceedings of two13 symposia Restoring native fish to the lower Colorado River interactions of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 NV and13 Restoring natural13 function within a modified riverine environment the lower Colorado River13 July13 8-shy‐913 1998 Las Vegas NV US Fish and13 Wildlife13 Service Southwest Region AlbuquerqueNew Mexico

Marsh13 P13 C13 and J13 E Brooks13 198913 Predation13 by ictalurid catfishes as a deterrent13 toreestablishment of hatchery-shy‐reared13 razorback sucker The Southwestern Naturalist34188-shy‐195

Matthews R A 2005 Ichthyopthirus multifiliis Fouquet and Ichthyopthirosis infreshwater13 teleosts13 Pages13 159-shy‐218 in Advances in Parasitology volume 59 J RBaker R Muller D Rollinson (eds) Academic Press

McCarthy13 M S and W L Minckley 1987 Age estimation for razorback sucker (PiscesCatostomidae) from13 Lake Mohave Arizona and Nevada Journal of the Arizona-shy‐Nevada Academy of Science 2187-shy‐97

Minckley13 W L13 198313 Status of the razorback13 sucker13 Xyrauchen texanus (Abbot)13 in13 thelower Colorado River basin13 The Southwestern13 Naturalist13 28(2) 165-shy‐187

Minckley13 W L13 199113 Native fished of the Grand Canyon13 region an obituary13 Pages 124-shy‐177 in Colorado River ecology and dam13 management National Academy PressWashington13 DC

Minckley13 C13 O and M LaBarbara13 199913 Report13 on13 native fish grow-shy‐out facilities13 at Cibolaand Imperial National Wildlife Refuges 1993-shy‐199513 US Fish and13 Wildlife Service13 Parker Fishery Resources Office Parker Arizona

Modde13 T13 199613 Juvenile razorback sucker (Xyrauchen texanus) in a managed wetlandadjacent13 to the Green13 River13 Great13 Basin13 Naturalist13 56375-shy‐376

Modde T KP Burnham and E J Wick 1996 Population status of the razorback sucker13 inthe middle Green River (USA) Conservation13 biology 10 110-shy‐119

Modde13 T13 and G13 B Haines13 200513 Survival13 and growth of stocked razorback13 sucker andbonytail in multiple floodplain wetlands of the middle Green River under resetconditions13 Final report prepared for Upper Colorado13 River13 Basin RecoveryImplimentation Program US Fish and Wildlife Service Vernal 66 pp

54

13

Modde T Z H Bowen and D C Kitcheyan 2005 Spatial and temporal use of a spawning13 site in the middle Green River by wild hatchery-shy‐reared13 razorback suckers13 Transactions of the American Fisheries Society 134937-shy‐944

Mueller13 G13 199213 The native fish work13 group13 -shy‐ a multiagency endeavor to improve thestatus of the razorback sucker in Lake Mohave AZ-shy‐NV13 Proceedings of the DesertFishes Council 2369

Mueller G 1995 A program13 for maintaining the razorback sucker in Lake MohaveAmerican Fisheries Society Symposium 15127-shy‐135

Mueller13 G13 200613 Ecology of the bonytail13 and razorback13 sucker and the role of offchannelhabitats13 in their13 recovery Scientific13 investigations13 report 2006-shy‐5065 US GeologicalSurvey13 Denver

Mueller G and E Wick 1998 Testing of golf course ponds at Page Arizona for suitability13 as grow-shy‐out facility for razorback sucker using surplus fish from13 Ouray NationalFish Hatchery National Park Service US Fish and13 Wildlife13 Service and UtahDivision of Wildlife13 Resources 28 pages

Mueller13 G13 and T13 Burke13 200513 Survival13 of young13 razorback13 sucker (Xyrauchen texanus) inrelation to13 stocking rates13 (fishha)13 and13 in the presence13 or absence13 of predatorcommunities in Lake Mohave Arizona-shy‐Nevada13 Pages13 155-shy‐16313 in Proceedings of two13 symposia restoring native fish to the lower Colorado River interaction13 of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 Nevada US Fish and Wildlife13 Service Southwest Region Albuquerque New Mexico

Mueller13 G13 J13 Carpenter13 and P13 C13 Marsh13 200413 Cibola13 High Levee Pond annual report 2004US Geological Survey Fort Collins13 Science Center13 Colorado13 and Arizona StateUniversity Tempe 23 pages

Nesler T P K Christopherson J M Hudson C W McAda F Pfeifer and T E Czapla 2003An integrated stocking plan for razorback sucker bonytail and Colorado13 pikeminnow for the Upper Colorado River Endangered Fish Recovery ProgramAddendum13 to State Stocking Plans Upper Colorado River Basin Recovery13 Implementation Program 12 pp

Papoulias13 D and W13 L Minckley13 1992 Effects13 of foo availability13 on survival and growth13 of larval razorback suckers13 in ponds Transactions of the American Fisheries Society121340-shy‐355

Paukert13 C P D L Ward13 P J Sponholtz13 and K13 D Hilwig13 Effects13 of repeated hoopnetting13 on bonytail chub13 Journal of Freshwater13 Ecology13 20(4) 649-shy‐653

Pfeifer F M13 C Baker13 and M13 Montagne13 199913 Propagation13 facilities13 in the13 Grand Valley13 (24 Road13 Hatchery13 Horsethief13 Ponds and13 grow-shy‐out ponds) for captive rearing of

55

13

endangered13 fishes for the13 Upper Colorado13 River Basin13 Colorado13 River Recovery13 Program FY 99 annual project report Project No 29a13 US Fish and Wildlife Service13 Grand13 Junction13 5pp

Pfeifer F S Seversen and M Montagne 2003 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2003 annual reportProject No 29b13 US Fish and Wildlife13 Service Vernal13 4pp

Rabago-shy‐Castro J L Sanchez13 J G Perez-shy‐Castaneda R and13 Gonzalez-shy‐Gonzlez A 2006Effects of the prophylactic use of Romet-shy‐3013 and13 copper13 sulfate13 on growth13 condition13 and feeding13 indicies in13 channel13 catfish (Ictalurus punctatus) Aquaculture 253 343-shy‐349

Reinitz GL L E Orme and F N Hitzel 1979 Variations of body compositio and growth13 among strains of rainbow trout Transactions of the American Fisheries Society 108204-shy‐207

Ruppert13 J13 B P B Holden13 and P D Abate 1999 Age estimation and growth of razorbacksucker13 Xyrauchen texanus in Lake13 Mead Nevada Proceedings13 of the Desert FishesCouncil 3040

Schnoor K D and J Logan 2002 Operation and maintenance of JW Mumma nativeaquatic13 species restoration facility Colorado Colorado River Recovery Program FY2002 annual project report13 Project No 29d Colorado13 Division of Wildlife Alamosa3pp

Salisbury13 L13 1998 Factors13 affecting razorback13 sucker growth13 in Lake13 Mohave backwaters13 MS Thesis13 Unviersity13 of Nevada13 Las13 Vegas

Schooley J13 D13 and P C13 Marsh13 2007 Stocking of endangerdd13 razorback13 suckers13 in thelower Colorado River Basin13 over three decades 1974-shy‐2004 North American Journalof Fisheries Management 27 43-shy‐51

Severson S H H M Tyus and G B Haines 1992 An evaluation of feeds for raisingrazorback sucker Xyrauchen texanus Journal of Applied Aquaculture 155-shy‐65

Toney D P 1974 Observations13 on the13 propagation13 and13 rearing13 of two13 endangered species13 in a hatchery environment Proceedings of the Annual Conference of the Western13 Association of State Game and Fish Commissions 54 252-shy‐259

Tyus H M13 1998 Razorback sucker13 (Xyrauchen texanus) recovery plan13 University13 ofColorado Center for Limnology Boulder13 76 pages

Tyus H M13 and13 S H Severson 1990 Growth13 and13 survival of larval razorback suckers fedfive formulated diets The Progressive Fish Culturist 52197-shy‐200

56

13

Ulibarri M E 2003 Annual report fiscal year 2001 Dexter National Fish Hatchery13 andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 26 pages

Ulibarri M E 2003 Annual report fiscal year 2002 Dexter National Fish Hatchery andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 59 pages

USBR 2006 Lower13 Colorado13 River Multi-shy‐Species Conservation Program final fishaugmentation plan Boulder City 19 pp

USFWS 2002 Razorback sucker (Xyraouchen texanus) recovery goals Amendment andsupplement to the Razorback Sucker Recovery Plan13 US Fish and Wildlife Service13 Region 6 Denver13 Colorado

USFWS 1999 Annual report 1999 Ouray National Fish Hatchery Vernal 25pp

USFWS 2004 Management plan for the big-shy‐river13 fishes of the13 lower13 Colorado13 river basinamendment and supplement to the bonytail humpback chub Coloradopikeminnow and razorback sucker recovery plans

USFWS13 2005 Station13 profile13 of the13 Dexter13 National Fish Hatchery13 and Technology CenterUS Fish and Wildlife13 Service Dexter

Valdez R A P G Mangan R Smith and B Nilson 1982 Upper Colorado River fisheriesinvestigations13 inW H Miller J J Valentine D L Archer H M Tyus R A Valdezand L13 Kaeding13 editors13 Colorado River Fishery13 Project13 Part 2 Field13 investigations13 US Bureau of Reclamation Salt Lake City Utah

WBNFH 2004 Culture methods of the endangered razorback sucker Xyrauchen texanusUS Fish and Wildlife13 Service Willow Beach National Fish Hatchery13 8 pp

Ward D 2008 Effects of disease treatments on growth of razorback sucker ReportSubmitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 Inpartial fulfillment of work task C10 agreement number 06FG30039

Ward13 D13 M Childs and W Persons 2007 Factors13 affecting13 growth13 of razorback sucker13 (Xyrauchen texanus) in captivity Literature review and knowledge assessmentReport Submitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 In partial fulfillment of work task C10 agreement number 06FG30039

57

Appendices

Appendix 1 Survey Questions Survey of Razorback Sucker Culture in the

Southwestern United States

The enclosed survey is being distributed by the Arizona Game and Fish Department to razorback sucker culture facilities throughout

the Southwestern United States The purpose of this survey is to consolidate information regarding culture of this species so that

appropriate facility improvements can be considered for Bubbling Ponds Hatchery in Arizona Specifically we wish to increase

growth rate and production efficiency at the hatchery Information gathered in this survey will be summarized in a final report to US

Bureau of Reclamation in Boulder City NV and disseminated to all facilities that participate in the survey A workshop to discuss

the findings of this study as well as to share general information concerning razorback sucker culture will be organized by the

Arizona Game and Fish Department at the conclusion of this study and all participants will be invited

Thank you for taking the time to fill out this survey Please contact Mike Childs if you have questions or would like to discuss the

survey

Mike Childs

mchildssedonanet

(928) 639-1346

(928) 634-1279

Facility_____________________________________ Date___________________

Contact Phone _____________________________

ContactPerson_______________________________

Contact Email _______________________________

1 Water quality ranges at this culture facility

Season

Spring (Mar-May) Summer (Jun-Aug) Fall (Sept-Nov) Winter (Dec-Feb)

Temperature (C)

PH

DO (mgL)

PO4 (mgL)

TDS (mgL)

Hardness (mgL)

CaCO3

Pathogens

37

13

limit the amount of feed hatchery managers can give fish in these ponds sometimes for

days or weeks at a time which further reduces growth during warm13 weather

Our data13 suggests that13 growth rates at the Bubbling13 Ponds Fish Hatchery are likely

as high as possible given13 the pond densities required to meet production goals and the Ich-shy‐

infested water that feeds the facility Sorting practices are successful in helping as many

fish as possible reach stocking length as fast as possible Unlined ponds may be able to

grow13 large13 fish at low13 densities13 but whatever factors allow13 for that13 growth are not13 able to

overcome high fish density The removal of invasive13 fis that act as13 a host for the13 parasite13

Ich fish from13 the Bubbling13 Ponds spring13 allowed the highest13 growth rate at 032 mmday13

(96 mmmonth) but that growth rate decreased again as Ich re-shy‐infested13 the13 hatchery13

Consistently13 achieving13 growth13 rates13 as high or substantially13 higher than13 this13 will likely13

require13 significant changes in rearing practices that may not be practical in order to13 reach13

numerical production13 goals

Two major changes that might result in higher growth rates are substantially

reducing fish density and modifying the way spring water is delivered to the facility (via

either repeated chemical treatments or enclosed concrete water diversions) to eliminate

Ich from13 the hatchery source water Other potential changes not address by our work

include13 flow-shy‐training razorbacks much previous literature including MSCP-shy‐funded13 work

on razorback suckers13 suggests13 that fish growing13 in flowing water will grow13 faster than fish

in still water (Jorgensen and Jobling 1994) Furthermore there are a wide variety of

potential benefits associated with growing13 fish13 in flowing13 water in addition13 to increased

growth13 rates13 (Davidson13 199713 Castro13 et al13 2011) Another option13 for increasing13 growth13

rates13 include13 changing to13 intensive13 culture13 in large circular13 tanks

Finally given that the stocking of smaller razorbacks has met with very little

success13 perhaps13 BPH13 goals13 could13 be13 changed from13 producing 12000 fish at 300+ mm per

year to a smaller number of very large fish each year Growing fewer larger fish could

potentially be accomplished in the same time frame as more smaller fish but a better

understanding13 of how density13 alters growth13 rate13 would13 be13 required to13 be13 confident of this

49

13

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower13 Colorado13 River Multi-shy‐Species13

Conservation Program13 (LCRMSCP) under Work Task C10 We13 thank Ty Wolters13 Tom13

Burke13 and Eric13 Volkman for their support of this research and Frank Agygos and Dave

Billingsly13 of the Bubbling13 Ponds Fish Hatchery13 for their willingness to participate in13 this

research13 and13 for their technical assistance We also thank the LCRMSCP fish group from13

Boulder City13 NV for their assistance with harvesting13 ponds and tagging13 fish13

50

13

Literature13 CitedAnders P J 1998 Conservation aquaculture and endangered species can objective science13

prevail13 over risk13 anxiety Fisheries 23(11) 28-shy‐31

Anderson R O and R M Nuemann 1996 Length weight and associated structural indicesPages 447 ndash 482 in B R Murphy13 and D13 W Willis13 editors13 Fisheries techniques13 2ndedtion American Fisheries13 Society13 Bethesda13 Maryland

Bain M B J T Finn and H E Brooks 1988 Streamflow regulation and fish communitystructure13 Ecology13 69382-shy‐392

Bays J H Zarbock R Whitman and T Murphy 2005 Conceptual design and managementof native13 fish refugia on the13 lower13 Colorado13 River In13 CL Spring13 and13 S Leoneditors Proceedings of two symposia Restoring native fish to the lower ColoradoRiver13 interactions13 of native and non-shy‐native13 fishes 13ndash1413 July13 1999 Las13 Vegas13 Nevada13 Restoring13 natural function within a modified riverine environment thelower Colorado River13 8ndash913 July13 1998 U S Fish and13 Wildlife13 Service Southwestern13 Region Albuquerque New Mexico Pages 167-shy‐177

Bertalanffy L Von 1957 Quantitative laws in metabolism13 and growth13 Q Rev Biology 32217 ndash 231

Bingham T B Scheer and C McAda 2003 Propagation facilities in Grand Valley (24 RoadHatchery Horsethief13 Ponds and13 grow-shy‐out ponds) for captive13 rearing13 ofendangered13 fishes for the13 upper13 Colorado13 River basin13 Colorado River RecoveryProgram FY2003 annual project report13 US Fish and13 Wildlife13 Service GrandJunction13 4pp

Birchell G J and K Christopherson 2004 Survival growth and recruitment of larval andjuvenile razorback13 sucker (Xyrauchen texanus) introduced13 into13 floodplain13 depressions13 of the13 Green River Utah13 Final report13 Upper13 Colorado13 RiverEndangered Fish Recovery Program13 Project No C-shy‐6RZ Publication Number 04-shy‐1513 Utah13 Division of Wildlife13 Resources Salt Lake13 City13 Utah13 67 pages

Brannon E L 1993 The perpetual oversight of hatchery programs Fishery Research 1819-shy‐27

Brett J R 1979 Environmental Factors and growth pages 599-shy‐67513 InW S Hoar13 D13 J13 Randall and J R Brett (eds) Fish Physiology Volume 8 Bioenergetics and GrowthAcademic Press New York

Brooks J E 1986 Annual reintroduction and monitoring report for razorback suckerXyrauchen texanus in the Gila River Basin Arizona 1985 US Fish and WildlifeService13 Offices of Endangered13 Species and Fishery13 Resources Albuquerque 23 pp

51

13

Brunson13 R E and K D13 Christopherson13 200513 Larval13 razorback13 sucker and bonytailsurvival and13 growth13 in the13 presence13 of nonnative13 fish in the13 Baeser13 floodplainwetland of the middle Green River Final report prepared for Upper13 Colorado RiverBasin Endangered Fish Recovery Program Project No C-shy‐6-shy‐rz-shy‐bt Publication13 No 05-shy‐26 Utah13 Division of Wildlife13 Resources13 Vernal13 32 pp

Bulkley R V and R Pimentel 1983 Temperature preference and avoidance by adultrazorback suckers Transactions of the American Fisheries Society 112601-shy‐607

Burke13 T13 199513 Rearing13 wild razorback13 sucker larvae in13 lake-shy‐side13 backwaters13 LakeMohave ArizonaNevada Proceedings of the Desert Fishes Council 2635

Busacker G P I R Adelman and E M Goolish13 199013 Growth13 Pages 363 ndash 387 in C BSchreck and p B Moyle editors Methods for fish biology American FisheriesSociety Bethesda Maryland

Castro V B Grisdale-shy‐Helland S J Helland T Kristensen S M Jorgensen J Helgrud13 GClaireaux A P Farrell A Krasnov and H Takle 2011 Aerobic training stimulatesgrowth and promotes disease resistance in Atlantic salmon (Salmo salar)Comparative Biochemistry and Physiology -shy‐ Part A Molecular amp IntegrativePhysiology13 160(2) 278-shy‐290

Czapla T E 2002 Facilities plan for the production of endangered fishes to meet statestocking13 plans13 as13 part of the13 Upper13 Colorado13 River Endangered13 Fish RecoveryProgram Upper Colorado River Basin Recovery Implementation Program US Fishand Wildlife Service13 Denver13 9 pp

Davidson W 1997 The effects13 of exercise13 training on teleost fish a review of recentliterature Comput Biochem Physiol 117A67ndash75

Figiel Jr C R 2005 Annual report fiscal year 2004 Willow Beach National13 Fish HatcheryUS Fish and Wildlife13 Service Willow Beach 17 pp

Figiel Jr C R M E Ulibarri G Carmichael J Seals and J N Hanson 2005 Intensive13 fish13 culture of warmwater native fishes at a coldwater fish hatchery Pages 164-shy‐16613 inProceedings of two symposia restoring native fish to the lower Colorado13 River13 interaction13 of native13 and13 non-shy‐native13 fishes July13 13-shy‐1413 1999 Las Vegas Nevada USFish and Wildlife Service Southwest Region Albuquerque New Mexico

Gerking13 S D 1978 Ecology of freshwater fish13 production13 Halstead Press13 New13 York

Gustafson W and Q Bradwisch 2000 Wahweap operation and maintenance -shy‐-shy‐ UtahColorado River Recovery Program FY 2000 annual project report Project No 29cUtah13 Division of Wildlife13 Resources Page AZ 3pp

52

13

Hamman R L 1985 Induced spawning of hatchery-shy‐reared13 razorback sucker ProgressivFish Culturist 47(3) 187-shy‐189

Hanson J N 1996 Annual report fiscal year 1996 Willow Beach National Fish HatcheryUS Fish and Wildlife Service13 Willow Beach 9pp

Irving D S Seversen and M Montagne 2004 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2004 annual project13 report Report No 29b US Fish and13 Wildlife13 Service Vernal 3pp

Jorgensen E H and13 M Jobling 1994 Feeding and13 growth13 of exercised13 and13 unexercised13 juvenile Atlantic salmon in freshwater and performance after transfer to seawaterAquaculture International 2 154-shy‐164

Kaeding L R and D B Osmundson 198913 Colorado13 Squawfish13 and13 razorback sucker grow-shy‐out pond studies as part of conservation measures for the green mountain andRuedi reservoir water sales Final report for agreement number 6-shy‐AA-shy‐60-shy‐00150

Koebele13 B P13 198513 Growth and the size hierarchy effect an experimental assessment ofthree proposed mechanisms activity differences disproportional food acquisition13 pysiological stress Environmental Biology of Fishes 12 181-shy‐188

Kretschmann A E and L L Leslie 2006 Razorback sucker (Xyrauchen texanus) status13 reproduction and recruitment in Senator Wash Reservoir CA Final Report13 to USBurea of Reclamation Cooperative Agreement No 00-shy‐FG-shy‐34-shy‐ 0009 p 32 ArizonaGame and Fish Department Phoenix

Marsh13 P13 C13 1987a13 Digestive tract13 contents13 of adult razorback suckers13 in Lake13 MohaveArizona-shy‐Nevada Transactions of the American Fisheries Society 116117-shy‐119

Marsh P C 1987b Native fishes at Buenos Aires National Wildlife Refuge and ArizonaState University Research Park Arizona opportunities for management researchand public13 education13 on13 endangered species13 Proceedings of the Desert13 FishesCouncil 1967-shy‐78

Marsh P C 1994 Rearing native Colorado River fishes in golf course ponds Arizona StateUniversity Tempe 22 + pages

Marsh13 P13 C13 200013 Fish population13 status and evaluation13 in13 the Cibola13 High Levee PondFinal report agreement number 99-shy‐FG-shy‐30-shy‐00051 US Bureau of ReclamationBoulder City13 Nevada13 20 pages

Marsh P C and C A Pacey 1998 Growth of wild adult razorback suckers13 in Lake13 Mohave13 Arizona-shy‐Nevada13 Final report13 US Bureau of Reclamation Boulder City Nevada 25pages + appendices

53

13

Marsh P C B R Kesner and C A Pacey 2005 Repatriation as s management strategy13 to13 conserve a critically13 imperiled fish species North American Journal of FisheriesManagement 25 547-shy‐556

Marsh P C and C A Pacey 2005 Immiscibility of native and non-shy‐native13 fishes Pages 59-shy‐63 inMJ13 Brouder13 CL13 Springer13 and CS13 Leon13 editors13 Proceedings of two13 symposia Restoring native fish to the lower Colorado River interactions of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 NV and13 Restoring natural13 function within a modified riverine environment the lower Colorado River13 July13 8-shy‐913 1998 Las Vegas NV US Fish and13 Wildlife13 Service Southwest Region AlbuquerqueNew Mexico

Marsh13 P13 C13 and J13 E Brooks13 198913 Predation13 by ictalurid catfishes as a deterrent13 toreestablishment of hatchery-shy‐reared13 razorback sucker The Southwestern Naturalist34188-shy‐195

Matthews R A 2005 Ichthyopthirus multifiliis Fouquet and Ichthyopthirosis infreshwater13 teleosts13 Pages13 159-shy‐218 in Advances in Parasitology volume 59 J RBaker R Muller D Rollinson (eds) Academic Press

McCarthy13 M S and W L Minckley 1987 Age estimation for razorback sucker (PiscesCatostomidae) from13 Lake Mohave Arizona and Nevada Journal of the Arizona-shy‐Nevada Academy of Science 2187-shy‐97

Minckley13 W L13 198313 Status of the razorback13 sucker13 Xyrauchen texanus (Abbot)13 in13 thelower Colorado River basin13 The Southwestern13 Naturalist13 28(2) 165-shy‐187

Minckley13 W L13 199113 Native fished of the Grand Canyon13 region an obituary13 Pages 124-shy‐177 in Colorado River ecology and dam13 management National Academy PressWashington13 DC

Minckley13 C13 O and M LaBarbara13 199913 Report13 on13 native fish grow-shy‐out facilities13 at Cibolaand Imperial National Wildlife Refuges 1993-shy‐199513 US Fish and13 Wildlife Service13 Parker Fishery Resources Office Parker Arizona

Modde13 T13 199613 Juvenile razorback sucker (Xyrauchen texanus) in a managed wetlandadjacent13 to the Green13 River13 Great13 Basin13 Naturalist13 56375-shy‐376

Modde T KP Burnham and E J Wick 1996 Population status of the razorback sucker13 inthe middle Green River (USA) Conservation13 biology 10 110-shy‐119

Modde13 T13 and G13 B Haines13 200513 Survival13 and growth of stocked razorback13 sucker andbonytail in multiple floodplain wetlands of the middle Green River under resetconditions13 Final report prepared for Upper Colorado13 River13 Basin RecoveryImplimentation Program US Fish and Wildlife Service Vernal 66 pp

54

13

Modde T Z H Bowen and D C Kitcheyan 2005 Spatial and temporal use of a spawning13 site in the middle Green River by wild hatchery-shy‐reared13 razorback suckers13 Transactions of the American Fisheries Society 134937-shy‐944

Mueller13 G13 199213 The native fish work13 group13 -shy‐ a multiagency endeavor to improve thestatus of the razorback sucker in Lake Mohave AZ-shy‐NV13 Proceedings of the DesertFishes Council 2369

Mueller G 1995 A program13 for maintaining the razorback sucker in Lake MohaveAmerican Fisheries Society Symposium 15127-shy‐135

Mueller13 G13 200613 Ecology of the bonytail13 and razorback13 sucker and the role of offchannelhabitats13 in their13 recovery Scientific13 investigations13 report 2006-shy‐5065 US GeologicalSurvey13 Denver

Mueller G and E Wick 1998 Testing of golf course ponds at Page Arizona for suitability13 as grow-shy‐out facility for razorback sucker using surplus fish from13 Ouray NationalFish Hatchery National Park Service US Fish and13 Wildlife13 Service and UtahDivision of Wildlife13 Resources 28 pages

Mueller13 G13 and T13 Burke13 200513 Survival13 of young13 razorback13 sucker (Xyrauchen texanus) inrelation to13 stocking rates13 (fishha)13 and13 in the presence13 or absence13 of predatorcommunities in Lake Mohave Arizona-shy‐Nevada13 Pages13 155-shy‐16313 in Proceedings of two13 symposia restoring native fish to the lower Colorado River interaction13 of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 Nevada US Fish and Wildlife13 Service Southwest Region Albuquerque New Mexico

Mueller13 G13 J13 Carpenter13 and P13 C13 Marsh13 200413 Cibola13 High Levee Pond annual report 2004US Geological Survey Fort Collins13 Science Center13 Colorado13 and Arizona StateUniversity Tempe 23 pages

Nesler T P K Christopherson J M Hudson C W McAda F Pfeifer and T E Czapla 2003An integrated stocking plan for razorback sucker bonytail and Colorado13 pikeminnow for the Upper Colorado River Endangered Fish Recovery ProgramAddendum13 to State Stocking Plans Upper Colorado River Basin Recovery13 Implementation Program 12 pp

Papoulias13 D and W13 L Minckley13 1992 Effects13 of foo availability13 on survival and growth13 of larval razorback suckers13 in ponds Transactions of the American Fisheries Society121340-shy‐355

Paukert13 C P D L Ward13 P J Sponholtz13 and K13 D Hilwig13 Effects13 of repeated hoopnetting13 on bonytail chub13 Journal of Freshwater13 Ecology13 20(4) 649-shy‐653

Pfeifer F M13 C Baker13 and M13 Montagne13 199913 Propagation13 facilities13 in the13 Grand Valley13 (24 Road13 Hatchery13 Horsethief13 Ponds and13 grow-shy‐out ponds) for captive rearing of

55

13

endangered13 fishes for the13 Upper Colorado13 River Basin13 Colorado13 River Recovery13 Program FY 99 annual project report Project No 29a13 US Fish and Wildlife Service13 Grand13 Junction13 5pp

Pfeifer F S Seversen and M Montagne 2003 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2003 annual reportProject No 29b13 US Fish and Wildlife13 Service Vernal13 4pp

Rabago-shy‐Castro J L Sanchez13 J G Perez-shy‐Castaneda R and13 Gonzalez-shy‐Gonzlez A 2006Effects of the prophylactic use of Romet-shy‐3013 and13 copper13 sulfate13 on growth13 condition13 and feeding13 indicies in13 channel13 catfish (Ictalurus punctatus) Aquaculture 253 343-shy‐349

Reinitz GL L E Orme and F N Hitzel 1979 Variations of body compositio and growth13 among strains of rainbow trout Transactions of the American Fisheries Society 108204-shy‐207

Ruppert13 J13 B P B Holden13 and P D Abate 1999 Age estimation and growth of razorbacksucker13 Xyrauchen texanus in Lake13 Mead Nevada Proceedings13 of the Desert FishesCouncil 3040

Schnoor K D and J Logan 2002 Operation and maintenance of JW Mumma nativeaquatic13 species restoration facility Colorado Colorado River Recovery Program FY2002 annual project report13 Project No 29d Colorado13 Division of Wildlife Alamosa3pp

Salisbury13 L13 1998 Factors13 affecting razorback13 sucker growth13 in Lake13 Mohave backwaters13 MS Thesis13 Unviersity13 of Nevada13 Las13 Vegas

Schooley J13 D13 and P C13 Marsh13 2007 Stocking of endangerdd13 razorback13 suckers13 in thelower Colorado River Basin13 over three decades 1974-shy‐2004 North American Journalof Fisheries Management 27 43-shy‐51

Severson S H H M Tyus and G B Haines 1992 An evaluation of feeds for raisingrazorback sucker Xyrauchen texanus Journal of Applied Aquaculture 155-shy‐65

Toney D P 1974 Observations13 on the13 propagation13 and13 rearing13 of two13 endangered species13 in a hatchery environment Proceedings of the Annual Conference of the Western13 Association of State Game and Fish Commissions 54 252-shy‐259

Tyus H M13 1998 Razorback sucker13 (Xyrauchen texanus) recovery plan13 University13 ofColorado Center for Limnology Boulder13 76 pages

Tyus H M13 and13 S H Severson 1990 Growth13 and13 survival of larval razorback suckers fedfive formulated diets The Progressive Fish Culturist 52197-shy‐200

56

13

Ulibarri M E 2003 Annual report fiscal year 2001 Dexter National Fish Hatchery13 andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 26 pages

Ulibarri M E 2003 Annual report fiscal year 2002 Dexter National Fish Hatchery andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 59 pages

USBR 2006 Lower13 Colorado13 River Multi-shy‐Species Conservation Program final fishaugmentation plan Boulder City 19 pp

USFWS 2002 Razorback sucker (Xyraouchen texanus) recovery goals Amendment andsupplement to the Razorback Sucker Recovery Plan13 US Fish and Wildlife Service13 Region 6 Denver13 Colorado

USFWS 1999 Annual report 1999 Ouray National Fish Hatchery Vernal 25pp

USFWS 2004 Management plan for the big-shy‐river13 fishes of the13 lower13 Colorado13 river basinamendment and supplement to the bonytail humpback chub Coloradopikeminnow and razorback sucker recovery plans

USFWS13 2005 Station13 profile13 of the13 Dexter13 National Fish Hatchery13 and Technology CenterUS Fish and Wildlife13 Service Dexter

Valdez R A P G Mangan R Smith and B Nilson 1982 Upper Colorado River fisheriesinvestigations13 inW H Miller J J Valentine D L Archer H M Tyus R A Valdezand L13 Kaeding13 editors13 Colorado River Fishery13 Project13 Part 2 Field13 investigations13 US Bureau of Reclamation Salt Lake City Utah

WBNFH 2004 Culture methods of the endangered razorback sucker Xyrauchen texanusUS Fish and Wildlife13 Service Willow Beach National Fish Hatchery13 8 pp

Ward D 2008 Effects of disease treatments on growth of razorback sucker ReportSubmitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 Inpartial fulfillment of work task C10 agreement number 06FG30039

Ward13 D13 M Childs and W Persons 2007 Factors13 affecting13 growth13 of razorback sucker13 (Xyrauchen texanus) in captivity Literature review and knowledge assessmentReport Submitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 In partial fulfillment of work task C10 agreement number 06FG30039

57

Appendices

Appendix 1 Survey Questions Survey of Razorback Sucker Culture in the

Southwestern United States

The enclosed survey is being distributed by the Arizona Game and Fish Department to razorback sucker culture facilities throughout

the Southwestern United States The purpose of this survey is to consolidate information regarding culture of this species so that

appropriate facility improvements can be considered for Bubbling Ponds Hatchery in Arizona Specifically we wish to increase

growth rate and production efficiency at the hatchery Information gathered in this survey will be summarized in a final report to US

Bureau of Reclamation in Boulder City NV and disseminated to all facilities that participate in the survey A workshop to discuss

the findings of this study as well as to share general information concerning razorback sucker culture will be organized by the

Arizona Game and Fish Department at the conclusion of this study and all participants will be invited

Thank you for taking the time to fill out this survey Please contact Mike Childs if you have questions or would like to discuss the

survey

Mike Childs

mchildssedonanet

(928) 639-1346

(928) 634-1279

Facility_____________________________________ Date___________________

Contact Phone _____________________________

ContactPerson_______________________________

Contact Email _______________________________

1 Water quality ranges at this culture facility

Season

Spring (Mar-May) Summer (Jun-Aug) Fall (Sept-Nov) Winter (Dec-Feb)

Temperature (C)

PH

DO (mgL)

PO4 (mgL)

TDS (mgL)

Hardness (mgL)

CaCO3

Pathogens

37

13

Acknowledgements

Funding for this project was provided by the U S Bureau of Reclamation in partial

fulfillment of a cooperative agreement with the Lower13 Colorado13 River Multi-shy‐Species13

Conservation Program13 (LCRMSCP) under Work Task C10 We13 thank Ty Wolters13 Tom13

Burke13 and Eric13 Volkman for their support of this research and Frank Agygos and Dave

Billingsly13 of the Bubbling13 Ponds Fish Hatchery13 for their willingness to participate in13 this

research13 and13 for their technical assistance We also thank the LCRMSCP fish group from13

Boulder City13 NV for their assistance with harvesting13 ponds and tagging13 fish13

50

13

Literature13 CitedAnders P J 1998 Conservation aquaculture and endangered species can objective science13

prevail13 over risk13 anxiety Fisheries 23(11) 28-shy‐31

Anderson R O and R M Nuemann 1996 Length weight and associated structural indicesPages 447 ndash 482 in B R Murphy13 and D13 W Willis13 editors13 Fisheries techniques13 2ndedtion American Fisheries13 Society13 Bethesda13 Maryland

Bain M B J T Finn and H E Brooks 1988 Streamflow regulation and fish communitystructure13 Ecology13 69382-shy‐392

Bays J H Zarbock R Whitman and T Murphy 2005 Conceptual design and managementof native13 fish refugia on the13 lower13 Colorado13 River In13 CL Spring13 and13 S Leoneditors Proceedings of two symposia Restoring native fish to the lower ColoradoRiver13 interactions13 of native and non-shy‐native13 fishes 13ndash1413 July13 1999 Las13 Vegas13 Nevada13 Restoring13 natural function within a modified riverine environment thelower Colorado River13 8ndash913 July13 1998 U S Fish and13 Wildlife13 Service Southwestern13 Region Albuquerque New Mexico Pages 167-shy‐177

Bertalanffy L Von 1957 Quantitative laws in metabolism13 and growth13 Q Rev Biology 32217 ndash 231

Bingham T B Scheer and C McAda 2003 Propagation facilities in Grand Valley (24 RoadHatchery Horsethief13 Ponds and13 grow-shy‐out ponds) for captive13 rearing13 ofendangered13 fishes for the13 upper13 Colorado13 River basin13 Colorado River RecoveryProgram FY2003 annual project report13 US Fish and13 Wildlife13 Service GrandJunction13 4pp

Birchell G J and K Christopherson 2004 Survival growth and recruitment of larval andjuvenile razorback13 sucker (Xyrauchen texanus) introduced13 into13 floodplain13 depressions13 of the13 Green River Utah13 Final report13 Upper13 Colorado13 RiverEndangered Fish Recovery Program13 Project No C-shy‐6RZ Publication Number 04-shy‐1513 Utah13 Division of Wildlife13 Resources Salt Lake13 City13 Utah13 67 pages

Brannon E L 1993 The perpetual oversight of hatchery programs Fishery Research 1819-shy‐27

Brett J R 1979 Environmental Factors and growth pages 599-shy‐67513 InW S Hoar13 D13 J13 Randall and J R Brett (eds) Fish Physiology Volume 8 Bioenergetics and GrowthAcademic Press New York

Brooks J E 1986 Annual reintroduction and monitoring report for razorback suckerXyrauchen texanus in the Gila River Basin Arizona 1985 US Fish and WildlifeService13 Offices of Endangered13 Species and Fishery13 Resources Albuquerque 23 pp

51

13

Brunson13 R E and K D13 Christopherson13 200513 Larval13 razorback13 sucker and bonytailsurvival and13 growth13 in the13 presence13 of nonnative13 fish in the13 Baeser13 floodplainwetland of the middle Green River Final report prepared for Upper13 Colorado RiverBasin Endangered Fish Recovery Program Project No C-shy‐6-shy‐rz-shy‐bt Publication13 No 05-shy‐26 Utah13 Division of Wildlife13 Resources13 Vernal13 32 pp

Bulkley R V and R Pimentel 1983 Temperature preference and avoidance by adultrazorback suckers Transactions of the American Fisheries Society 112601-shy‐607

Burke13 T13 199513 Rearing13 wild razorback13 sucker larvae in13 lake-shy‐side13 backwaters13 LakeMohave ArizonaNevada Proceedings of the Desert Fishes Council 2635

Busacker G P I R Adelman and E M Goolish13 199013 Growth13 Pages 363 ndash 387 in C BSchreck and p B Moyle editors Methods for fish biology American FisheriesSociety Bethesda Maryland

Castro V B Grisdale-shy‐Helland S J Helland T Kristensen S M Jorgensen J Helgrud13 GClaireaux A P Farrell A Krasnov and H Takle 2011 Aerobic training stimulatesgrowth and promotes disease resistance in Atlantic salmon (Salmo salar)Comparative Biochemistry and Physiology -shy‐ Part A Molecular amp IntegrativePhysiology13 160(2) 278-shy‐290

Czapla T E 2002 Facilities plan for the production of endangered fishes to meet statestocking13 plans13 as13 part of the13 Upper13 Colorado13 River Endangered13 Fish RecoveryProgram Upper Colorado River Basin Recovery Implementation Program US Fishand Wildlife Service13 Denver13 9 pp

Davidson W 1997 The effects13 of exercise13 training on teleost fish a review of recentliterature Comput Biochem Physiol 117A67ndash75

Figiel Jr C R 2005 Annual report fiscal year 2004 Willow Beach National13 Fish HatcheryUS Fish and Wildlife13 Service Willow Beach 17 pp

Figiel Jr C R M E Ulibarri G Carmichael J Seals and J N Hanson 2005 Intensive13 fish13 culture of warmwater native fishes at a coldwater fish hatchery Pages 164-shy‐16613 inProceedings of two symposia restoring native fish to the lower Colorado13 River13 interaction13 of native13 and13 non-shy‐native13 fishes July13 13-shy‐1413 1999 Las Vegas Nevada USFish and Wildlife Service Southwest Region Albuquerque New Mexico

Gerking13 S D 1978 Ecology of freshwater fish13 production13 Halstead Press13 New13 York

Gustafson W and Q Bradwisch 2000 Wahweap operation and maintenance -shy‐-shy‐ UtahColorado River Recovery Program FY 2000 annual project report Project No 29cUtah13 Division of Wildlife13 Resources Page AZ 3pp

52

13

Hamman R L 1985 Induced spawning of hatchery-shy‐reared13 razorback sucker ProgressivFish Culturist 47(3) 187-shy‐189

Hanson J N 1996 Annual report fiscal year 1996 Willow Beach National Fish HatcheryUS Fish and Wildlife Service13 Willow Beach 9pp

Irving D S Seversen and M Montagne 2004 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2004 annual project13 report Report No 29b US Fish and13 Wildlife13 Service Vernal 3pp

Jorgensen E H and13 M Jobling 1994 Feeding and13 growth13 of exercised13 and13 unexercised13 juvenile Atlantic salmon in freshwater and performance after transfer to seawaterAquaculture International 2 154-shy‐164

Kaeding L R and D B Osmundson 198913 Colorado13 Squawfish13 and13 razorback sucker grow-shy‐out pond studies as part of conservation measures for the green mountain andRuedi reservoir water sales Final report for agreement number 6-shy‐AA-shy‐60-shy‐00150

Koebele13 B P13 198513 Growth and the size hierarchy effect an experimental assessment ofthree proposed mechanisms activity differences disproportional food acquisition13 pysiological stress Environmental Biology of Fishes 12 181-shy‐188

Kretschmann A E and L L Leslie 2006 Razorback sucker (Xyrauchen texanus) status13 reproduction and recruitment in Senator Wash Reservoir CA Final Report13 to USBurea of Reclamation Cooperative Agreement No 00-shy‐FG-shy‐34-shy‐ 0009 p 32 ArizonaGame and Fish Department Phoenix

Marsh13 P13 C13 1987a13 Digestive tract13 contents13 of adult razorback suckers13 in Lake13 MohaveArizona-shy‐Nevada Transactions of the American Fisheries Society 116117-shy‐119

Marsh P C 1987b Native fishes at Buenos Aires National Wildlife Refuge and ArizonaState University Research Park Arizona opportunities for management researchand public13 education13 on13 endangered species13 Proceedings of the Desert13 FishesCouncil 1967-shy‐78

Marsh P C 1994 Rearing native Colorado River fishes in golf course ponds Arizona StateUniversity Tempe 22 + pages

Marsh13 P13 C13 200013 Fish population13 status and evaluation13 in13 the Cibola13 High Levee PondFinal report agreement number 99-shy‐FG-shy‐30-shy‐00051 US Bureau of ReclamationBoulder City13 Nevada13 20 pages

Marsh P C and C A Pacey 1998 Growth of wild adult razorback suckers13 in Lake13 Mohave13 Arizona-shy‐Nevada13 Final report13 US Bureau of Reclamation Boulder City Nevada 25pages + appendices

53

13

Marsh P C B R Kesner and C A Pacey 2005 Repatriation as s management strategy13 to13 conserve a critically13 imperiled fish species North American Journal of FisheriesManagement 25 547-shy‐556

Marsh P C and C A Pacey 2005 Immiscibility of native and non-shy‐native13 fishes Pages 59-shy‐63 inMJ13 Brouder13 CL13 Springer13 and CS13 Leon13 editors13 Proceedings of two13 symposia Restoring native fish to the lower Colorado River interactions of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 NV and13 Restoring natural13 function within a modified riverine environment the lower Colorado River13 July13 8-shy‐913 1998 Las Vegas NV US Fish and13 Wildlife13 Service Southwest Region AlbuquerqueNew Mexico

Marsh13 P13 C13 and J13 E Brooks13 198913 Predation13 by ictalurid catfishes as a deterrent13 toreestablishment of hatchery-shy‐reared13 razorback sucker The Southwestern Naturalist34188-shy‐195

Matthews R A 2005 Ichthyopthirus multifiliis Fouquet and Ichthyopthirosis infreshwater13 teleosts13 Pages13 159-shy‐218 in Advances in Parasitology volume 59 J RBaker R Muller D Rollinson (eds) Academic Press

McCarthy13 M S and W L Minckley 1987 Age estimation for razorback sucker (PiscesCatostomidae) from13 Lake Mohave Arizona and Nevada Journal of the Arizona-shy‐Nevada Academy of Science 2187-shy‐97

Minckley13 W L13 198313 Status of the razorback13 sucker13 Xyrauchen texanus (Abbot)13 in13 thelower Colorado River basin13 The Southwestern13 Naturalist13 28(2) 165-shy‐187

Minckley13 W L13 199113 Native fished of the Grand Canyon13 region an obituary13 Pages 124-shy‐177 in Colorado River ecology and dam13 management National Academy PressWashington13 DC

Minckley13 C13 O and M LaBarbara13 199913 Report13 on13 native fish grow-shy‐out facilities13 at Cibolaand Imperial National Wildlife Refuges 1993-shy‐199513 US Fish and13 Wildlife Service13 Parker Fishery Resources Office Parker Arizona

Modde13 T13 199613 Juvenile razorback sucker (Xyrauchen texanus) in a managed wetlandadjacent13 to the Green13 River13 Great13 Basin13 Naturalist13 56375-shy‐376

Modde T KP Burnham and E J Wick 1996 Population status of the razorback sucker13 inthe middle Green River (USA) Conservation13 biology 10 110-shy‐119

Modde13 T13 and G13 B Haines13 200513 Survival13 and growth of stocked razorback13 sucker andbonytail in multiple floodplain wetlands of the middle Green River under resetconditions13 Final report prepared for Upper Colorado13 River13 Basin RecoveryImplimentation Program US Fish and Wildlife Service Vernal 66 pp

54

13

Modde T Z H Bowen and D C Kitcheyan 2005 Spatial and temporal use of a spawning13 site in the middle Green River by wild hatchery-shy‐reared13 razorback suckers13 Transactions of the American Fisheries Society 134937-shy‐944

Mueller13 G13 199213 The native fish work13 group13 -shy‐ a multiagency endeavor to improve thestatus of the razorback sucker in Lake Mohave AZ-shy‐NV13 Proceedings of the DesertFishes Council 2369

Mueller G 1995 A program13 for maintaining the razorback sucker in Lake MohaveAmerican Fisheries Society Symposium 15127-shy‐135

Mueller13 G13 200613 Ecology of the bonytail13 and razorback13 sucker and the role of offchannelhabitats13 in their13 recovery Scientific13 investigations13 report 2006-shy‐5065 US GeologicalSurvey13 Denver

Mueller G and E Wick 1998 Testing of golf course ponds at Page Arizona for suitability13 as grow-shy‐out facility for razorback sucker using surplus fish from13 Ouray NationalFish Hatchery National Park Service US Fish and13 Wildlife13 Service and UtahDivision of Wildlife13 Resources 28 pages

Mueller13 G13 and T13 Burke13 200513 Survival13 of young13 razorback13 sucker (Xyrauchen texanus) inrelation to13 stocking rates13 (fishha)13 and13 in the presence13 or absence13 of predatorcommunities in Lake Mohave Arizona-shy‐Nevada13 Pages13 155-shy‐16313 in Proceedings of two13 symposia restoring native fish to the lower Colorado River interaction13 of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 Nevada US Fish and Wildlife13 Service Southwest Region Albuquerque New Mexico

Mueller13 G13 J13 Carpenter13 and P13 C13 Marsh13 200413 Cibola13 High Levee Pond annual report 2004US Geological Survey Fort Collins13 Science Center13 Colorado13 and Arizona StateUniversity Tempe 23 pages

Nesler T P K Christopherson J M Hudson C W McAda F Pfeifer and T E Czapla 2003An integrated stocking plan for razorback sucker bonytail and Colorado13 pikeminnow for the Upper Colorado River Endangered Fish Recovery ProgramAddendum13 to State Stocking Plans Upper Colorado River Basin Recovery13 Implementation Program 12 pp

Papoulias13 D and W13 L Minckley13 1992 Effects13 of foo availability13 on survival and growth13 of larval razorback suckers13 in ponds Transactions of the American Fisheries Society121340-shy‐355

Paukert13 C P D L Ward13 P J Sponholtz13 and K13 D Hilwig13 Effects13 of repeated hoopnetting13 on bonytail chub13 Journal of Freshwater13 Ecology13 20(4) 649-shy‐653

Pfeifer F M13 C Baker13 and M13 Montagne13 199913 Propagation13 facilities13 in the13 Grand Valley13 (24 Road13 Hatchery13 Horsethief13 Ponds and13 grow-shy‐out ponds) for captive rearing of

55

13

endangered13 fishes for the13 Upper Colorado13 River Basin13 Colorado13 River Recovery13 Program FY 99 annual project report Project No 29a13 US Fish and Wildlife Service13 Grand13 Junction13 5pp

Pfeifer F S Seversen and M Montagne 2003 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2003 annual reportProject No 29b13 US Fish and Wildlife13 Service Vernal13 4pp

Rabago-shy‐Castro J L Sanchez13 J G Perez-shy‐Castaneda R and13 Gonzalez-shy‐Gonzlez A 2006Effects of the prophylactic use of Romet-shy‐3013 and13 copper13 sulfate13 on growth13 condition13 and feeding13 indicies in13 channel13 catfish (Ictalurus punctatus) Aquaculture 253 343-shy‐349

Reinitz GL L E Orme and F N Hitzel 1979 Variations of body compositio and growth13 among strains of rainbow trout Transactions of the American Fisheries Society 108204-shy‐207

Ruppert13 J13 B P B Holden13 and P D Abate 1999 Age estimation and growth of razorbacksucker13 Xyrauchen texanus in Lake13 Mead Nevada Proceedings13 of the Desert FishesCouncil 3040

Schnoor K D and J Logan 2002 Operation and maintenance of JW Mumma nativeaquatic13 species restoration facility Colorado Colorado River Recovery Program FY2002 annual project report13 Project No 29d Colorado13 Division of Wildlife Alamosa3pp

Salisbury13 L13 1998 Factors13 affecting razorback13 sucker growth13 in Lake13 Mohave backwaters13 MS Thesis13 Unviersity13 of Nevada13 Las13 Vegas

Schooley J13 D13 and P C13 Marsh13 2007 Stocking of endangerdd13 razorback13 suckers13 in thelower Colorado River Basin13 over three decades 1974-shy‐2004 North American Journalof Fisheries Management 27 43-shy‐51

Severson S H H M Tyus and G B Haines 1992 An evaluation of feeds for raisingrazorback sucker Xyrauchen texanus Journal of Applied Aquaculture 155-shy‐65

Toney D P 1974 Observations13 on the13 propagation13 and13 rearing13 of two13 endangered species13 in a hatchery environment Proceedings of the Annual Conference of the Western13 Association of State Game and Fish Commissions 54 252-shy‐259

Tyus H M13 1998 Razorback sucker13 (Xyrauchen texanus) recovery plan13 University13 ofColorado Center for Limnology Boulder13 76 pages

Tyus H M13 and13 S H Severson 1990 Growth13 and13 survival of larval razorback suckers fedfive formulated diets The Progressive Fish Culturist 52197-shy‐200

56

13

Ulibarri M E 2003 Annual report fiscal year 2001 Dexter National Fish Hatchery13 andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 26 pages

Ulibarri M E 2003 Annual report fiscal year 2002 Dexter National Fish Hatchery andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 59 pages

USBR 2006 Lower13 Colorado13 River Multi-shy‐Species Conservation Program final fishaugmentation plan Boulder City 19 pp

USFWS 2002 Razorback sucker (Xyraouchen texanus) recovery goals Amendment andsupplement to the Razorback Sucker Recovery Plan13 US Fish and Wildlife Service13 Region 6 Denver13 Colorado

USFWS 1999 Annual report 1999 Ouray National Fish Hatchery Vernal 25pp

USFWS 2004 Management plan for the big-shy‐river13 fishes of the13 lower13 Colorado13 river basinamendment and supplement to the bonytail humpback chub Coloradopikeminnow and razorback sucker recovery plans

USFWS13 2005 Station13 profile13 of the13 Dexter13 National Fish Hatchery13 and Technology CenterUS Fish and Wildlife13 Service Dexter

Valdez R A P G Mangan R Smith and B Nilson 1982 Upper Colorado River fisheriesinvestigations13 inW H Miller J J Valentine D L Archer H M Tyus R A Valdezand L13 Kaeding13 editors13 Colorado River Fishery13 Project13 Part 2 Field13 investigations13 US Bureau of Reclamation Salt Lake City Utah

WBNFH 2004 Culture methods of the endangered razorback sucker Xyrauchen texanusUS Fish and Wildlife13 Service Willow Beach National Fish Hatchery13 8 pp

Ward D 2008 Effects of disease treatments on growth of razorback sucker ReportSubmitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 Inpartial fulfillment of work task C10 agreement number 06FG30039

Ward13 D13 M Childs and W Persons 2007 Factors13 affecting13 growth13 of razorback sucker13 (Xyrauchen texanus) in captivity Literature review and knowledge assessmentReport Submitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 In partial fulfillment of work task C10 agreement number 06FG30039

57

Appendices

Appendix 1 Survey Questions Survey of Razorback Sucker Culture in the

Southwestern United States

The enclosed survey is being distributed by the Arizona Game and Fish Department to razorback sucker culture facilities throughout

the Southwestern United States The purpose of this survey is to consolidate information regarding culture of this species so that

appropriate facility improvements can be considered for Bubbling Ponds Hatchery in Arizona Specifically we wish to increase

growth rate and production efficiency at the hatchery Information gathered in this survey will be summarized in a final report to US

Bureau of Reclamation in Boulder City NV and disseminated to all facilities that participate in the survey A workshop to discuss

the findings of this study as well as to share general information concerning razorback sucker culture will be organized by the

Arizona Game and Fish Department at the conclusion of this study and all participants will be invited

Thank you for taking the time to fill out this survey Please contact Mike Childs if you have questions or would like to discuss the

survey

Mike Childs

mchildssedonanet

(928) 639-1346

(928) 634-1279

Facility_____________________________________ Date___________________

Contact Phone _____________________________

ContactPerson_______________________________

Contact Email _______________________________

1 Water quality ranges at this culture facility

Season

Spring (Mar-May) Summer (Jun-Aug) Fall (Sept-Nov) Winter (Dec-Feb)

Temperature (C)

PH

DO (mgL)

PO4 (mgL)

TDS (mgL)

Hardness (mgL)

CaCO3

Pathogens

37

13

Literature13 CitedAnders P J 1998 Conservation aquaculture and endangered species can objective science13

prevail13 over risk13 anxiety Fisheries 23(11) 28-shy‐31

Anderson R O and R M Nuemann 1996 Length weight and associated structural indicesPages 447 ndash 482 in B R Murphy13 and D13 W Willis13 editors13 Fisheries techniques13 2ndedtion American Fisheries13 Society13 Bethesda13 Maryland

Bain M B J T Finn and H E Brooks 1988 Streamflow regulation and fish communitystructure13 Ecology13 69382-shy‐392

Bays J H Zarbock R Whitman and T Murphy 2005 Conceptual design and managementof native13 fish refugia on the13 lower13 Colorado13 River In13 CL Spring13 and13 S Leoneditors Proceedings of two symposia Restoring native fish to the lower ColoradoRiver13 interactions13 of native and non-shy‐native13 fishes 13ndash1413 July13 1999 Las13 Vegas13 Nevada13 Restoring13 natural function within a modified riverine environment thelower Colorado River13 8ndash913 July13 1998 U S Fish and13 Wildlife13 Service Southwestern13 Region Albuquerque New Mexico Pages 167-shy‐177

Bertalanffy L Von 1957 Quantitative laws in metabolism13 and growth13 Q Rev Biology 32217 ndash 231

Bingham T B Scheer and C McAda 2003 Propagation facilities in Grand Valley (24 RoadHatchery Horsethief13 Ponds and13 grow-shy‐out ponds) for captive13 rearing13 ofendangered13 fishes for the13 upper13 Colorado13 River basin13 Colorado River RecoveryProgram FY2003 annual project report13 US Fish and13 Wildlife13 Service GrandJunction13 4pp

Birchell G J and K Christopherson 2004 Survival growth and recruitment of larval andjuvenile razorback13 sucker (Xyrauchen texanus) introduced13 into13 floodplain13 depressions13 of the13 Green River Utah13 Final report13 Upper13 Colorado13 RiverEndangered Fish Recovery Program13 Project No C-shy‐6RZ Publication Number 04-shy‐1513 Utah13 Division of Wildlife13 Resources Salt Lake13 City13 Utah13 67 pages

Brannon E L 1993 The perpetual oversight of hatchery programs Fishery Research 1819-shy‐27

Brett J R 1979 Environmental Factors and growth pages 599-shy‐67513 InW S Hoar13 D13 J13 Randall and J R Brett (eds) Fish Physiology Volume 8 Bioenergetics and GrowthAcademic Press New York

Brooks J E 1986 Annual reintroduction and monitoring report for razorback suckerXyrauchen texanus in the Gila River Basin Arizona 1985 US Fish and WildlifeService13 Offices of Endangered13 Species and Fishery13 Resources Albuquerque 23 pp

51

13

Brunson13 R E and K D13 Christopherson13 200513 Larval13 razorback13 sucker and bonytailsurvival and13 growth13 in the13 presence13 of nonnative13 fish in the13 Baeser13 floodplainwetland of the middle Green River Final report prepared for Upper13 Colorado RiverBasin Endangered Fish Recovery Program Project No C-shy‐6-shy‐rz-shy‐bt Publication13 No 05-shy‐26 Utah13 Division of Wildlife13 Resources13 Vernal13 32 pp

Bulkley R V and R Pimentel 1983 Temperature preference and avoidance by adultrazorback suckers Transactions of the American Fisheries Society 112601-shy‐607

Burke13 T13 199513 Rearing13 wild razorback13 sucker larvae in13 lake-shy‐side13 backwaters13 LakeMohave ArizonaNevada Proceedings of the Desert Fishes Council 2635

Busacker G P I R Adelman and E M Goolish13 199013 Growth13 Pages 363 ndash 387 in C BSchreck and p B Moyle editors Methods for fish biology American FisheriesSociety Bethesda Maryland

Castro V B Grisdale-shy‐Helland S J Helland T Kristensen S M Jorgensen J Helgrud13 GClaireaux A P Farrell A Krasnov and H Takle 2011 Aerobic training stimulatesgrowth and promotes disease resistance in Atlantic salmon (Salmo salar)Comparative Biochemistry and Physiology -shy‐ Part A Molecular amp IntegrativePhysiology13 160(2) 278-shy‐290

Czapla T E 2002 Facilities plan for the production of endangered fishes to meet statestocking13 plans13 as13 part of the13 Upper13 Colorado13 River Endangered13 Fish RecoveryProgram Upper Colorado River Basin Recovery Implementation Program US Fishand Wildlife Service13 Denver13 9 pp

Davidson W 1997 The effects13 of exercise13 training on teleost fish a review of recentliterature Comput Biochem Physiol 117A67ndash75

Figiel Jr C R 2005 Annual report fiscal year 2004 Willow Beach National13 Fish HatcheryUS Fish and Wildlife13 Service Willow Beach 17 pp

Figiel Jr C R M E Ulibarri G Carmichael J Seals and J N Hanson 2005 Intensive13 fish13 culture of warmwater native fishes at a coldwater fish hatchery Pages 164-shy‐16613 inProceedings of two symposia restoring native fish to the lower Colorado13 River13 interaction13 of native13 and13 non-shy‐native13 fishes July13 13-shy‐1413 1999 Las Vegas Nevada USFish and Wildlife Service Southwest Region Albuquerque New Mexico

Gerking13 S D 1978 Ecology of freshwater fish13 production13 Halstead Press13 New13 York

Gustafson W and Q Bradwisch 2000 Wahweap operation and maintenance -shy‐-shy‐ UtahColorado River Recovery Program FY 2000 annual project report Project No 29cUtah13 Division of Wildlife13 Resources Page AZ 3pp

52

13

Hamman R L 1985 Induced spawning of hatchery-shy‐reared13 razorback sucker ProgressivFish Culturist 47(3) 187-shy‐189

Hanson J N 1996 Annual report fiscal year 1996 Willow Beach National Fish HatcheryUS Fish and Wildlife Service13 Willow Beach 9pp

Irving D S Seversen and M Montagne 2004 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2004 annual project13 report Report No 29b US Fish and13 Wildlife13 Service Vernal 3pp

Jorgensen E H and13 M Jobling 1994 Feeding and13 growth13 of exercised13 and13 unexercised13 juvenile Atlantic salmon in freshwater and performance after transfer to seawaterAquaculture International 2 154-shy‐164

Kaeding L R and D B Osmundson 198913 Colorado13 Squawfish13 and13 razorback sucker grow-shy‐out pond studies as part of conservation measures for the green mountain andRuedi reservoir water sales Final report for agreement number 6-shy‐AA-shy‐60-shy‐00150

Koebele13 B P13 198513 Growth and the size hierarchy effect an experimental assessment ofthree proposed mechanisms activity differences disproportional food acquisition13 pysiological stress Environmental Biology of Fishes 12 181-shy‐188

Kretschmann A E and L L Leslie 2006 Razorback sucker (Xyrauchen texanus) status13 reproduction and recruitment in Senator Wash Reservoir CA Final Report13 to USBurea of Reclamation Cooperative Agreement No 00-shy‐FG-shy‐34-shy‐ 0009 p 32 ArizonaGame and Fish Department Phoenix

Marsh13 P13 C13 1987a13 Digestive tract13 contents13 of adult razorback suckers13 in Lake13 MohaveArizona-shy‐Nevada Transactions of the American Fisheries Society 116117-shy‐119

Marsh P C 1987b Native fishes at Buenos Aires National Wildlife Refuge and ArizonaState University Research Park Arizona opportunities for management researchand public13 education13 on13 endangered species13 Proceedings of the Desert13 FishesCouncil 1967-shy‐78

Marsh P C 1994 Rearing native Colorado River fishes in golf course ponds Arizona StateUniversity Tempe 22 + pages

Marsh13 P13 C13 200013 Fish population13 status and evaluation13 in13 the Cibola13 High Levee PondFinal report agreement number 99-shy‐FG-shy‐30-shy‐00051 US Bureau of ReclamationBoulder City13 Nevada13 20 pages

Marsh P C and C A Pacey 1998 Growth of wild adult razorback suckers13 in Lake13 Mohave13 Arizona-shy‐Nevada13 Final report13 US Bureau of Reclamation Boulder City Nevada 25pages + appendices

53

13

Marsh P C B R Kesner and C A Pacey 2005 Repatriation as s management strategy13 to13 conserve a critically13 imperiled fish species North American Journal of FisheriesManagement 25 547-shy‐556

Marsh P C and C A Pacey 2005 Immiscibility of native and non-shy‐native13 fishes Pages 59-shy‐63 inMJ13 Brouder13 CL13 Springer13 and CS13 Leon13 editors13 Proceedings of two13 symposia Restoring native fish to the lower Colorado River interactions of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 NV and13 Restoring natural13 function within a modified riverine environment the lower Colorado River13 July13 8-shy‐913 1998 Las Vegas NV US Fish and13 Wildlife13 Service Southwest Region AlbuquerqueNew Mexico

Marsh13 P13 C13 and J13 E Brooks13 198913 Predation13 by ictalurid catfishes as a deterrent13 toreestablishment of hatchery-shy‐reared13 razorback sucker The Southwestern Naturalist34188-shy‐195

Matthews R A 2005 Ichthyopthirus multifiliis Fouquet and Ichthyopthirosis infreshwater13 teleosts13 Pages13 159-shy‐218 in Advances in Parasitology volume 59 J RBaker R Muller D Rollinson (eds) Academic Press

McCarthy13 M S and W L Minckley 1987 Age estimation for razorback sucker (PiscesCatostomidae) from13 Lake Mohave Arizona and Nevada Journal of the Arizona-shy‐Nevada Academy of Science 2187-shy‐97

Minckley13 W L13 198313 Status of the razorback13 sucker13 Xyrauchen texanus (Abbot)13 in13 thelower Colorado River basin13 The Southwestern13 Naturalist13 28(2) 165-shy‐187

Minckley13 W L13 199113 Native fished of the Grand Canyon13 region an obituary13 Pages 124-shy‐177 in Colorado River ecology and dam13 management National Academy PressWashington13 DC

Minckley13 C13 O and M LaBarbara13 199913 Report13 on13 native fish grow-shy‐out facilities13 at Cibolaand Imperial National Wildlife Refuges 1993-shy‐199513 US Fish and13 Wildlife Service13 Parker Fishery Resources Office Parker Arizona

Modde13 T13 199613 Juvenile razorback sucker (Xyrauchen texanus) in a managed wetlandadjacent13 to the Green13 River13 Great13 Basin13 Naturalist13 56375-shy‐376

Modde T KP Burnham and E J Wick 1996 Population status of the razorback sucker13 inthe middle Green River (USA) Conservation13 biology 10 110-shy‐119

Modde13 T13 and G13 B Haines13 200513 Survival13 and growth of stocked razorback13 sucker andbonytail in multiple floodplain wetlands of the middle Green River under resetconditions13 Final report prepared for Upper Colorado13 River13 Basin RecoveryImplimentation Program US Fish and Wildlife Service Vernal 66 pp

54

13

Modde T Z H Bowen and D C Kitcheyan 2005 Spatial and temporal use of a spawning13 site in the middle Green River by wild hatchery-shy‐reared13 razorback suckers13 Transactions of the American Fisheries Society 134937-shy‐944

Mueller13 G13 199213 The native fish work13 group13 -shy‐ a multiagency endeavor to improve thestatus of the razorback sucker in Lake Mohave AZ-shy‐NV13 Proceedings of the DesertFishes Council 2369

Mueller G 1995 A program13 for maintaining the razorback sucker in Lake MohaveAmerican Fisheries Society Symposium 15127-shy‐135

Mueller13 G13 200613 Ecology of the bonytail13 and razorback13 sucker and the role of offchannelhabitats13 in their13 recovery Scientific13 investigations13 report 2006-shy‐5065 US GeologicalSurvey13 Denver

Mueller G and E Wick 1998 Testing of golf course ponds at Page Arizona for suitability13 as grow-shy‐out facility for razorback sucker using surplus fish from13 Ouray NationalFish Hatchery National Park Service US Fish and13 Wildlife13 Service and UtahDivision of Wildlife13 Resources 28 pages

Mueller13 G13 and T13 Burke13 200513 Survival13 of young13 razorback13 sucker (Xyrauchen texanus) inrelation to13 stocking rates13 (fishha)13 and13 in the presence13 or absence13 of predatorcommunities in Lake Mohave Arizona-shy‐Nevada13 Pages13 155-shy‐16313 in Proceedings of two13 symposia restoring native fish to the lower Colorado River interaction13 of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 Nevada US Fish and Wildlife13 Service Southwest Region Albuquerque New Mexico

Mueller13 G13 J13 Carpenter13 and P13 C13 Marsh13 200413 Cibola13 High Levee Pond annual report 2004US Geological Survey Fort Collins13 Science Center13 Colorado13 and Arizona StateUniversity Tempe 23 pages

Nesler T P K Christopherson J M Hudson C W McAda F Pfeifer and T E Czapla 2003An integrated stocking plan for razorback sucker bonytail and Colorado13 pikeminnow for the Upper Colorado River Endangered Fish Recovery ProgramAddendum13 to State Stocking Plans Upper Colorado River Basin Recovery13 Implementation Program 12 pp

Papoulias13 D and W13 L Minckley13 1992 Effects13 of foo availability13 on survival and growth13 of larval razorback suckers13 in ponds Transactions of the American Fisheries Society121340-shy‐355

Paukert13 C P D L Ward13 P J Sponholtz13 and K13 D Hilwig13 Effects13 of repeated hoopnetting13 on bonytail chub13 Journal of Freshwater13 Ecology13 20(4) 649-shy‐653

Pfeifer F M13 C Baker13 and M13 Montagne13 199913 Propagation13 facilities13 in the13 Grand Valley13 (24 Road13 Hatchery13 Horsethief13 Ponds and13 grow-shy‐out ponds) for captive rearing of

55

13

endangered13 fishes for the13 Upper Colorado13 River Basin13 Colorado13 River Recovery13 Program FY 99 annual project report Project No 29a13 US Fish and Wildlife Service13 Grand13 Junction13 5pp

Pfeifer F S Seversen and M Montagne 2003 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2003 annual reportProject No 29b13 US Fish and Wildlife13 Service Vernal13 4pp

Rabago-shy‐Castro J L Sanchez13 J G Perez-shy‐Castaneda R and13 Gonzalez-shy‐Gonzlez A 2006Effects of the prophylactic use of Romet-shy‐3013 and13 copper13 sulfate13 on growth13 condition13 and feeding13 indicies in13 channel13 catfish (Ictalurus punctatus) Aquaculture 253 343-shy‐349

Reinitz GL L E Orme and F N Hitzel 1979 Variations of body compositio and growth13 among strains of rainbow trout Transactions of the American Fisheries Society 108204-shy‐207

Ruppert13 J13 B P B Holden13 and P D Abate 1999 Age estimation and growth of razorbacksucker13 Xyrauchen texanus in Lake13 Mead Nevada Proceedings13 of the Desert FishesCouncil 3040

Schnoor K D and J Logan 2002 Operation and maintenance of JW Mumma nativeaquatic13 species restoration facility Colorado Colorado River Recovery Program FY2002 annual project report13 Project No 29d Colorado13 Division of Wildlife Alamosa3pp

Salisbury13 L13 1998 Factors13 affecting razorback13 sucker growth13 in Lake13 Mohave backwaters13 MS Thesis13 Unviersity13 of Nevada13 Las13 Vegas

Schooley J13 D13 and P C13 Marsh13 2007 Stocking of endangerdd13 razorback13 suckers13 in thelower Colorado River Basin13 over three decades 1974-shy‐2004 North American Journalof Fisheries Management 27 43-shy‐51

Severson S H H M Tyus and G B Haines 1992 An evaluation of feeds for raisingrazorback sucker Xyrauchen texanus Journal of Applied Aquaculture 155-shy‐65

Toney D P 1974 Observations13 on the13 propagation13 and13 rearing13 of two13 endangered species13 in a hatchery environment Proceedings of the Annual Conference of the Western13 Association of State Game and Fish Commissions 54 252-shy‐259

Tyus H M13 1998 Razorback sucker13 (Xyrauchen texanus) recovery plan13 University13 ofColorado Center for Limnology Boulder13 76 pages

Tyus H M13 and13 S H Severson 1990 Growth13 and13 survival of larval razorback suckers fedfive formulated diets The Progressive Fish Culturist 52197-shy‐200

56

13

Ulibarri M E 2003 Annual report fiscal year 2001 Dexter National Fish Hatchery13 andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 26 pages

Ulibarri M E 2003 Annual report fiscal year 2002 Dexter National Fish Hatchery andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 59 pages

USBR 2006 Lower13 Colorado13 River Multi-shy‐Species Conservation Program final fishaugmentation plan Boulder City 19 pp

USFWS 2002 Razorback sucker (Xyraouchen texanus) recovery goals Amendment andsupplement to the Razorback Sucker Recovery Plan13 US Fish and Wildlife Service13 Region 6 Denver13 Colorado

USFWS 1999 Annual report 1999 Ouray National Fish Hatchery Vernal 25pp

USFWS 2004 Management plan for the big-shy‐river13 fishes of the13 lower13 Colorado13 river basinamendment and supplement to the bonytail humpback chub Coloradopikeminnow and razorback sucker recovery plans

USFWS13 2005 Station13 profile13 of the13 Dexter13 National Fish Hatchery13 and Technology CenterUS Fish and Wildlife13 Service Dexter

Valdez R A P G Mangan R Smith and B Nilson 1982 Upper Colorado River fisheriesinvestigations13 inW H Miller J J Valentine D L Archer H M Tyus R A Valdezand L13 Kaeding13 editors13 Colorado River Fishery13 Project13 Part 2 Field13 investigations13 US Bureau of Reclamation Salt Lake City Utah

WBNFH 2004 Culture methods of the endangered razorback sucker Xyrauchen texanusUS Fish and Wildlife13 Service Willow Beach National Fish Hatchery13 8 pp

Ward D 2008 Effects of disease treatments on growth of razorback sucker ReportSubmitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 Inpartial fulfillment of work task C10 agreement number 06FG30039

Ward13 D13 M Childs and W Persons 2007 Factors13 affecting13 growth13 of razorback sucker13 (Xyrauchen texanus) in captivity Literature review and knowledge assessmentReport Submitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 In partial fulfillment of work task C10 agreement number 06FG30039

57

Appendices

Appendix 1 Survey Questions Survey of Razorback Sucker Culture in the

Southwestern United States

The enclosed survey is being distributed by the Arizona Game and Fish Department to razorback sucker culture facilities throughout

the Southwestern United States The purpose of this survey is to consolidate information regarding culture of this species so that

appropriate facility improvements can be considered for Bubbling Ponds Hatchery in Arizona Specifically we wish to increase

growth rate and production efficiency at the hatchery Information gathered in this survey will be summarized in a final report to US

Bureau of Reclamation in Boulder City NV and disseminated to all facilities that participate in the survey A workshop to discuss

the findings of this study as well as to share general information concerning razorback sucker culture will be organized by the

Arizona Game and Fish Department at the conclusion of this study and all participants will be invited

Thank you for taking the time to fill out this survey Please contact Mike Childs if you have questions or would like to discuss the

survey

Mike Childs

mchildssedonanet

(928) 639-1346

(928) 634-1279

Facility_____________________________________ Date___________________

Contact Phone _____________________________

ContactPerson_______________________________

Contact Email _______________________________

1 Water quality ranges at this culture facility

Season

Spring (Mar-May) Summer (Jun-Aug) Fall (Sept-Nov) Winter (Dec-Feb)

Temperature (C)

PH

DO (mgL)

PO4 (mgL)

TDS (mgL)

Hardness (mgL)

CaCO3

Pathogens

37

13

Brunson13 R E and K D13 Christopherson13 200513 Larval13 razorback13 sucker and bonytailsurvival and13 growth13 in the13 presence13 of nonnative13 fish in the13 Baeser13 floodplainwetland of the middle Green River Final report prepared for Upper13 Colorado RiverBasin Endangered Fish Recovery Program Project No C-shy‐6-shy‐rz-shy‐bt Publication13 No 05-shy‐26 Utah13 Division of Wildlife13 Resources13 Vernal13 32 pp

Bulkley R V and R Pimentel 1983 Temperature preference and avoidance by adultrazorback suckers Transactions of the American Fisheries Society 112601-shy‐607

Burke13 T13 199513 Rearing13 wild razorback13 sucker larvae in13 lake-shy‐side13 backwaters13 LakeMohave ArizonaNevada Proceedings of the Desert Fishes Council 2635

Busacker G P I R Adelman and E M Goolish13 199013 Growth13 Pages 363 ndash 387 in C BSchreck and p B Moyle editors Methods for fish biology American FisheriesSociety Bethesda Maryland

Castro V B Grisdale-shy‐Helland S J Helland T Kristensen S M Jorgensen J Helgrud13 GClaireaux A P Farrell A Krasnov and H Takle 2011 Aerobic training stimulatesgrowth and promotes disease resistance in Atlantic salmon (Salmo salar)Comparative Biochemistry and Physiology -shy‐ Part A Molecular amp IntegrativePhysiology13 160(2) 278-shy‐290

Czapla T E 2002 Facilities plan for the production of endangered fishes to meet statestocking13 plans13 as13 part of the13 Upper13 Colorado13 River Endangered13 Fish RecoveryProgram Upper Colorado River Basin Recovery Implementation Program US Fishand Wildlife Service13 Denver13 9 pp

Davidson W 1997 The effects13 of exercise13 training on teleost fish a review of recentliterature Comput Biochem Physiol 117A67ndash75

Figiel Jr C R 2005 Annual report fiscal year 2004 Willow Beach National13 Fish HatcheryUS Fish and Wildlife13 Service Willow Beach 17 pp

Figiel Jr C R M E Ulibarri G Carmichael J Seals and J N Hanson 2005 Intensive13 fish13 culture of warmwater native fishes at a coldwater fish hatchery Pages 164-shy‐16613 inProceedings of two symposia restoring native fish to the lower Colorado13 River13 interaction13 of native13 and13 non-shy‐native13 fishes July13 13-shy‐1413 1999 Las Vegas Nevada USFish and Wildlife Service Southwest Region Albuquerque New Mexico

Gerking13 S D 1978 Ecology of freshwater fish13 production13 Halstead Press13 New13 York

Gustafson W and Q Bradwisch 2000 Wahweap operation and maintenance -shy‐-shy‐ UtahColorado River Recovery Program FY 2000 annual project report Project No 29cUtah13 Division of Wildlife13 Resources Page AZ 3pp

52

13

Hamman R L 1985 Induced spawning of hatchery-shy‐reared13 razorback sucker ProgressivFish Culturist 47(3) 187-shy‐189

Hanson J N 1996 Annual report fiscal year 1996 Willow Beach National Fish HatcheryUS Fish and Wildlife Service13 Willow Beach 9pp

Irving D S Seversen and M Montagne 2004 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2004 annual project13 report Report No 29b US Fish and13 Wildlife13 Service Vernal 3pp

Jorgensen E H and13 M Jobling 1994 Feeding and13 growth13 of exercised13 and13 unexercised13 juvenile Atlantic salmon in freshwater and performance after transfer to seawaterAquaculture International 2 154-shy‐164

Kaeding L R and D B Osmundson 198913 Colorado13 Squawfish13 and13 razorback sucker grow-shy‐out pond studies as part of conservation measures for the green mountain andRuedi reservoir water sales Final report for agreement number 6-shy‐AA-shy‐60-shy‐00150

Koebele13 B P13 198513 Growth and the size hierarchy effect an experimental assessment ofthree proposed mechanisms activity differences disproportional food acquisition13 pysiological stress Environmental Biology of Fishes 12 181-shy‐188

Kretschmann A E and L L Leslie 2006 Razorback sucker (Xyrauchen texanus) status13 reproduction and recruitment in Senator Wash Reservoir CA Final Report13 to USBurea of Reclamation Cooperative Agreement No 00-shy‐FG-shy‐34-shy‐ 0009 p 32 ArizonaGame and Fish Department Phoenix

Marsh13 P13 C13 1987a13 Digestive tract13 contents13 of adult razorback suckers13 in Lake13 MohaveArizona-shy‐Nevada Transactions of the American Fisheries Society 116117-shy‐119

Marsh P C 1987b Native fishes at Buenos Aires National Wildlife Refuge and ArizonaState University Research Park Arizona opportunities for management researchand public13 education13 on13 endangered species13 Proceedings of the Desert13 FishesCouncil 1967-shy‐78

Marsh P C 1994 Rearing native Colorado River fishes in golf course ponds Arizona StateUniversity Tempe 22 + pages

Marsh13 P13 C13 200013 Fish population13 status and evaluation13 in13 the Cibola13 High Levee PondFinal report agreement number 99-shy‐FG-shy‐30-shy‐00051 US Bureau of ReclamationBoulder City13 Nevada13 20 pages

Marsh P C and C A Pacey 1998 Growth of wild adult razorback suckers13 in Lake13 Mohave13 Arizona-shy‐Nevada13 Final report13 US Bureau of Reclamation Boulder City Nevada 25pages + appendices

53

13

Marsh P C B R Kesner and C A Pacey 2005 Repatriation as s management strategy13 to13 conserve a critically13 imperiled fish species North American Journal of FisheriesManagement 25 547-shy‐556

Marsh P C and C A Pacey 2005 Immiscibility of native and non-shy‐native13 fishes Pages 59-shy‐63 inMJ13 Brouder13 CL13 Springer13 and CS13 Leon13 editors13 Proceedings of two13 symposia Restoring native fish to the lower Colorado River interactions of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 NV and13 Restoring natural13 function within a modified riverine environment the lower Colorado River13 July13 8-shy‐913 1998 Las Vegas NV US Fish and13 Wildlife13 Service Southwest Region AlbuquerqueNew Mexico

Marsh13 P13 C13 and J13 E Brooks13 198913 Predation13 by ictalurid catfishes as a deterrent13 toreestablishment of hatchery-shy‐reared13 razorback sucker The Southwestern Naturalist34188-shy‐195

Matthews R A 2005 Ichthyopthirus multifiliis Fouquet and Ichthyopthirosis infreshwater13 teleosts13 Pages13 159-shy‐218 in Advances in Parasitology volume 59 J RBaker R Muller D Rollinson (eds) Academic Press

McCarthy13 M S and W L Minckley 1987 Age estimation for razorback sucker (PiscesCatostomidae) from13 Lake Mohave Arizona and Nevada Journal of the Arizona-shy‐Nevada Academy of Science 2187-shy‐97

Minckley13 W L13 198313 Status of the razorback13 sucker13 Xyrauchen texanus (Abbot)13 in13 thelower Colorado River basin13 The Southwestern13 Naturalist13 28(2) 165-shy‐187

Minckley13 W L13 199113 Native fished of the Grand Canyon13 region an obituary13 Pages 124-shy‐177 in Colorado River ecology and dam13 management National Academy PressWashington13 DC

Minckley13 C13 O and M LaBarbara13 199913 Report13 on13 native fish grow-shy‐out facilities13 at Cibolaand Imperial National Wildlife Refuges 1993-shy‐199513 US Fish and13 Wildlife Service13 Parker Fishery Resources Office Parker Arizona

Modde13 T13 199613 Juvenile razorback sucker (Xyrauchen texanus) in a managed wetlandadjacent13 to the Green13 River13 Great13 Basin13 Naturalist13 56375-shy‐376

Modde T KP Burnham and E J Wick 1996 Population status of the razorback sucker13 inthe middle Green River (USA) Conservation13 biology 10 110-shy‐119

Modde13 T13 and G13 B Haines13 200513 Survival13 and growth of stocked razorback13 sucker andbonytail in multiple floodplain wetlands of the middle Green River under resetconditions13 Final report prepared for Upper Colorado13 River13 Basin RecoveryImplimentation Program US Fish and Wildlife Service Vernal 66 pp

54

13

Modde T Z H Bowen and D C Kitcheyan 2005 Spatial and temporal use of a spawning13 site in the middle Green River by wild hatchery-shy‐reared13 razorback suckers13 Transactions of the American Fisheries Society 134937-shy‐944

Mueller13 G13 199213 The native fish work13 group13 -shy‐ a multiagency endeavor to improve thestatus of the razorback sucker in Lake Mohave AZ-shy‐NV13 Proceedings of the DesertFishes Council 2369

Mueller G 1995 A program13 for maintaining the razorback sucker in Lake MohaveAmerican Fisheries Society Symposium 15127-shy‐135

Mueller13 G13 200613 Ecology of the bonytail13 and razorback13 sucker and the role of offchannelhabitats13 in their13 recovery Scientific13 investigations13 report 2006-shy‐5065 US GeologicalSurvey13 Denver

Mueller G and E Wick 1998 Testing of golf course ponds at Page Arizona for suitability13 as grow-shy‐out facility for razorback sucker using surplus fish from13 Ouray NationalFish Hatchery National Park Service US Fish and13 Wildlife13 Service and UtahDivision of Wildlife13 Resources 28 pages

Mueller13 G13 and T13 Burke13 200513 Survival13 of young13 razorback13 sucker (Xyrauchen texanus) inrelation to13 stocking rates13 (fishha)13 and13 in the presence13 or absence13 of predatorcommunities in Lake Mohave Arizona-shy‐Nevada13 Pages13 155-shy‐16313 in Proceedings of two13 symposia restoring native fish to the lower Colorado River interaction13 of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 Nevada US Fish and Wildlife13 Service Southwest Region Albuquerque New Mexico

Mueller13 G13 J13 Carpenter13 and P13 C13 Marsh13 200413 Cibola13 High Levee Pond annual report 2004US Geological Survey Fort Collins13 Science Center13 Colorado13 and Arizona StateUniversity Tempe 23 pages

Nesler T P K Christopherson J M Hudson C W McAda F Pfeifer and T E Czapla 2003An integrated stocking plan for razorback sucker bonytail and Colorado13 pikeminnow for the Upper Colorado River Endangered Fish Recovery ProgramAddendum13 to State Stocking Plans Upper Colorado River Basin Recovery13 Implementation Program 12 pp

Papoulias13 D and W13 L Minckley13 1992 Effects13 of foo availability13 on survival and growth13 of larval razorback suckers13 in ponds Transactions of the American Fisheries Society121340-shy‐355

Paukert13 C P D L Ward13 P J Sponholtz13 and K13 D Hilwig13 Effects13 of repeated hoopnetting13 on bonytail chub13 Journal of Freshwater13 Ecology13 20(4) 649-shy‐653

Pfeifer F M13 C Baker13 and M13 Montagne13 199913 Propagation13 facilities13 in the13 Grand Valley13 (24 Road13 Hatchery13 Horsethief13 Ponds and13 grow-shy‐out ponds) for captive rearing of

55

13

endangered13 fishes for the13 Upper Colorado13 River Basin13 Colorado13 River Recovery13 Program FY 99 annual project report Project No 29a13 US Fish and Wildlife Service13 Grand13 Junction13 5pp

Pfeifer F S Seversen and M Montagne 2003 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2003 annual reportProject No 29b13 US Fish and Wildlife13 Service Vernal13 4pp

Rabago-shy‐Castro J L Sanchez13 J G Perez-shy‐Castaneda R and13 Gonzalez-shy‐Gonzlez A 2006Effects of the prophylactic use of Romet-shy‐3013 and13 copper13 sulfate13 on growth13 condition13 and feeding13 indicies in13 channel13 catfish (Ictalurus punctatus) Aquaculture 253 343-shy‐349

Reinitz GL L E Orme and F N Hitzel 1979 Variations of body compositio and growth13 among strains of rainbow trout Transactions of the American Fisheries Society 108204-shy‐207

Ruppert13 J13 B P B Holden13 and P D Abate 1999 Age estimation and growth of razorbacksucker13 Xyrauchen texanus in Lake13 Mead Nevada Proceedings13 of the Desert FishesCouncil 3040

Schnoor K D and J Logan 2002 Operation and maintenance of JW Mumma nativeaquatic13 species restoration facility Colorado Colorado River Recovery Program FY2002 annual project report13 Project No 29d Colorado13 Division of Wildlife Alamosa3pp

Salisbury13 L13 1998 Factors13 affecting razorback13 sucker growth13 in Lake13 Mohave backwaters13 MS Thesis13 Unviersity13 of Nevada13 Las13 Vegas

Schooley J13 D13 and P C13 Marsh13 2007 Stocking of endangerdd13 razorback13 suckers13 in thelower Colorado River Basin13 over three decades 1974-shy‐2004 North American Journalof Fisheries Management 27 43-shy‐51

Severson S H H M Tyus and G B Haines 1992 An evaluation of feeds for raisingrazorback sucker Xyrauchen texanus Journal of Applied Aquaculture 155-shy‐65

Toney D P 1974 Observations13 on the13 propagation13 and13 rearing13 of two13 endangered species13 in a hatchery environment Proceedings of the Annual Conference of the Western13 Association of State Game and Fish Commissions 54 252-shy‐259

Tyus H M13 1998 Razorback sucker13 (Xyrauchen texanus) recovery plan13 University13 ofColorado Center for Limnology Boulder13 76 pages

Tyus H M13 and13 S H Severson 1990 Growth13 and13 survival of larval razorback suckers fedfive formulated diets The Progressive Fish Culturist 52197-shy‐200

56

13

Ulibarri M E 2003 Annual report fiscal year 2001 Dexter National Fish Hatchery13 andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 26 pages

Ulibarri M E 2003 Annual report fiscal year 2002 Dexter National Fish Hatchery andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 59 pages

USBR 2006 Lower13 Colorado13 River Multi-shy‐Species Conservation Program final fishaugmentation plan Boulder City 19 pp

USFWS 2002 Razorback sucker (Xyraouchen texanus) recovery goals Amendment andsupplement to the Razorback Sucker Recovery Plan13 US Fish and Wildlife Service13 Region 6 Denver13 Colorado

USFWS 1999 Annual report 1999 Ouray National Fish Hatchery Vernal 25pp

USFWS 2004 Management plan for the big-shy‐river13 fishes of the13 lower13 Colorado13 river basinamendment and supplement to the bonytail humpback chub Coloradopikeminnow and razorback sucker recovery plans

USFWS13 2005 Station13 profile13 of the13 Dexter13 National Fish Hatchery13 and Technology CenterUS Fish and Wildlife13 Service Dexter

Valdez R A P G Mangan R Smith and B Nilson 1982 Upper Colorado River fisheriesinvestigations13 inW H Miller J J Valentine D L Archer H M Tyus R A Valdezand L13 Kaeding13 editors13 Colorado River Fishery13 Project13 Part 2 Field13 investigations13 US Bureau of Reclamation Salt Lake City Utah

WBNFH 2004 Culture methods of the endangered razorback sucker Xyrauchen texanusUS Fish and Wildlife13 Service Willow Beach National Fish Hatchery13 8 pp

Ward D 2008 Effects of disease treatments on growth of razorback sucker ReportSubmitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 Inpartial fulfillment of work task C10 agreement number 06FG30039

Ward13 D13 M Childs and W Persons 2007 Factors13 affecting13 growth13 of razorback sucker13 (Xyrauchen texanus) in captivity Literature review and knowledge assessmentReport Submitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 In partial fulfillment of work task C10 agreement number 06FG30039

57

Appendices

Appendix 1 Survey Questions Survey of Razorback Sucker Culture in the

Southwestern United States

The enclosed survey is being distributed by the Arizona Game and Fish Department to razorback sucker culture facilities throughout

the Southwestern United States The purpose of this survey is to consolidate information regarding culture of this species so that

appropriate facility improvements can be considered for Bubbling Ponds Hatchery in Arizona Specifically we wish to increase

growth rate and production efficiency at the hatchery Information gathered in this survey will be summarized in a final report to US

Bureau of Reclamation in Boulder City NV and disseminated to all facilities that participate in the survey A workshop to discuss

the findings of this study as well as to share general information concerning razorback sucker culture will be organized by the

Arizona Game and Fish Department at the conclusion of this study and all participants will be invited

Thank you for taking the time to fill out this survey Please contact Mike Childs if you have questions or would like to discuss the

survey

Mike Childs

mchildssedonanet

(928) 639-1346

(928) 634-1279

Facility_____________________________________ Date___________________

Contact Phone _____________________________

ContactPerson_______________________________

Contact Email _______________________________

1 Water quality ranges at this culture facility

Season

Spring (Mar-May) Summer (Jun-Aug) Fall (Sept-Nov) Winter (Dec-Feb)

Temperature (C)

PH

DO (mgL)

PO4 (mgL)

TDS (mgL)

Hardness (mgL)

CaCO3

Pathogens

37

13

Hamman R L 1985 Induced spawning of hatchery-shy‐reared13 razorback sucker ProgressivFish Culturist 47(3) 187-shy‐189

Hanson J N 1996 Annual report fiscal year 1996 Willow Beach National Fish HatcheryUS Fish and Wildlife Service13 Willow Beach 9pp

Irving D S Seversen and M Montagne 2004 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2004 annual project13 report Report No 29b US Fish and13 Wildlife13 Service Vernal 3pp

Jorgensen E H and13 M Jobling 1994 Feeding and13 growth13 of exercised13 and13 unexercised13 juvenile Atlantic salmon in freshwater and performance after transfer to seawaterAquaculture International 2 154-shy‐164

Kaeding L R and D B Osmundson 198913 Colorado13 Squawfish13 and13 razorback sucker grow-shy‐out pond studies as part of conservation measures for the green mountain andRuedi reservoir water sales Final report for agreement number 6-shy‐AA-shy‐60-shy‐00150

Koebele13 B P13 198513 Growth and the size hierarchy effect an experimental assessment ofthree proposed mechanisms activity differences disproportional food acquisition13 pysiological stress Environmental Biology of Fishes 12 181-shy‐188

Kretschmann A E and L L Leslie 2006 Razorback sucker (Xyrauchen texanus) status13 reproduction and recruitment in Senator Wash Reservoir CA Final Report13 to USBurea of Reclamation Cooperative Agreement No 00-shy‐FG-shy‐34-shy‐ 0009 p 32 ArizonaGame and Fish Department Phoenix

Marsh13 P13 C13 1987a13 Digestive tract13 contents13 of adult razorback suckers13 in Lake13 MohaveArizona-shy‐Nevada Transactions of the American Fisheries Society 116117-shy‐119

Marsh P C 1987b Native fishes at Buenos Aires National Wildlife Refuge and ArizonaState University Research Park Arizona opportunities for management researchand public13 education13 on13 endangered species13 Proceedings of the Desert13 FishesCouncil 1967-shy‐78

Marsh P C 1994 Rearing native Colorado River fishes in golf course ponds Arizona StateUniversity Tempe 22 + pages

Marsh13 P13 C13 200013 Fish population13 status and evaluation13 in13 the Cibola13 High Levee PondFinal report agreement number 99-shy‐FG-shy‐30-shy‐00051 US Bureau of ReclamationBoulder City13 Nevada13 20 pages

Marsh P C and C A Pacey 1998 Growth of wild adult razorback suckers13 in Lake13 Mohave13 Arizona-shy‐Nevada13 Final report13 US Bureau of Reclamation Boulder City Nevada 25pages + appendices

53

13

Marsh P C B R Kesner and C A Pacey 2005 Repatriation as s management strategy13 to13 conserve a critically13 imperiled fish species North American Journal of FisheriesManagement 25 547-shy‐556

Marsh P C and C A Pacey 2005 Immiscibility of native and non-shy‐native13 fishes Pages 59-shy‐63 inMJ13 Brouder13 CL13 Springer13 and CS13 Leon13 editors13 Proceedings of two13 symposia Restoring native fish to the lower Colorado River interactions of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 NV and13 Restoring natural13 function within a modified riverine environment the lower Colorado River13 July13 8-shy‐913 1998 Las Vegas NV US Fish and13 Wildlife13 Service Southwest Region AlbuquerqueNew Mexico

Marsh13 P13 C13 and J13 E Brooks13 198913 Predation13 by ictalurid catfishes as a deterrent13 toreestablishment of hatchery-shy‐reared13 razorback sucker The Southwestern Naturalist34188-shy‐195

Matthews R A 2005 Ichthyopthirus multifiliis Fouquet and Ichthyopthirosis infreshwater13 teleosts13 Pages13 159-shy‐218 in Advances in Parasitology volume 59 J RBaker R Muller D Rollinson (eds) Academic Press

McCarthy13 M S and W L Minckley 1987 Age estimation for razorback sucker (PiscesCatostomidae) from13 Lake Mohave Arizona and Nevada Journal of the Arizona-shy‐Nevada Academy of Science 2187-shy‐97

Minckley13 W L13 198313 Status of the razorback13 sucker13 Xyrauchen texanus (Abbot)13 in13 thelower Colorado River basin13 The Southwestern13 Naturalist13 28(2) 165-shy‐187

Minckley13 W L13 199113 Native fished of the Grand Canyon13 region an obituary13 Pages 124-shy‐177 in Colorado River ecology and dam13 management National Academy PressWashington13 DC

Minckley13 C13 O and M LaBarbara13 199913 Report13 on13 native fish grow-shy‐out facilities13 at Cibolaand Imperial National Wildlife Refuges 1993-shy‐199513 US Fish and13 Wildlife Service13 Parker Fishery Resources Office Parker Arizona

Modde13 T13 199613 Juvenile razorback sucker (Xyrauchen texanus) in a managed wetlandadjacent13 to the Green13 River13 Great13 Basin13 Naturalist13 56375-shy‐376

Modde T KP Burnham and E J Wick 1996 Population status of the razorback sucker13 inthe middle Green River (USA) Conservation13 biology 10 110-shy‐119

Modde13 T13 and G13 B Haines13 200513 Survival13 and growth of stocked razorback13 sucker andbonytail in multiple floodplain wetlands of the middle Green River under resetconditions13 Final report prepared for Upper Colorado13 River13 Basin RecoveryImplimentation Program US Fish and Wildlife Service Vernal 66 pp

54

13

Modde T Z H Bowen and D C Kitcheyan 2005 Spatial and temporal use of a spawning13 site in the middle Green River by wild hatchery-shy‐reared13 razorback suckers13 Transactions of the American Fisheries Society 134937-shy‐944

Mueller13 G13 199213 The native fish work13 group13 -shy‐ a multiagency endeavor to improve thestatus of the razorback sucker in Lake Mohave AZ-shy‐NV13 Proceedings of the DesertFishes Council 2369

Mueller G 1995 A program13 for maintaining the razorback sucker in Lake MohaveAmerican Fisheries Society Symposium 15127-shy‐135

Mueller13 G13 200613 Ecology of the bonytail13 and razorback13 sucker and the role of offchannelhabitats13 in their13 recovery Scientific13 investigations13 report 2006-shy‐5065 US GeologicalSurvey13 Denver

Mueller G and E Wick 1998 Testing of golf course ponds at Page Arizona for suitability13 as grow-shy‐out facility for razorback sucker using surplus fish from13 Ouray NationalFish Hatchery National Park Service US Fish and13 Wildlife13 Service and UtahDivision of Wildlife13 Resources 28 pages

Mueller13 G13 and T13 Burke13 200513 Survival13 of young13 razorback13 sucker (Xyrauchen texanus) inrelation to13 stocking rates13 (fishha)13 and13 in the presence13 or absence13 of predatorcommunities in Lake Mohave Arizona-shy‐Nevada13 Pages13 155-shy‐16313 in Proceedings of two13 symposia restoring native fish to the lower Colorado River interaction13 of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 Nevada US Fish and Wildlife13 Service Southwest Region Albuquerque New Mexico

Mueller13 G13 J13 Carpenter13 and P13 C13 Marsh13 200413 Cibola13 High Levee Pond annual report 2004US Geological Survey Fort Collins13 Science Center13 Colorado13 and Arizona StateUniversity Tempe 23 pages

Nesler T P K Christopherson J M Hudson C W McAda F Pfeifer and T E Czapla 2003An integrated stocking plan for razorback sucker bonytail and Colorado13 pikeminnow for the Upper Colorado River Endangered Fish Recovery ProgramAddendum13 to State Stocking Plans Upper Colorado River Basin Recovery13 Implementation Program 12 pp

Papoulias13 D and W13 L Minckley13 1992 Effects13 of foo availability13 on survival and growth13 of larval razorback suckers13 in ponds Transactions of the American Fisheries Society121340-shy‐355

Paukert13 C P D L Ward13 P J Sponholtz13 and K13 D Hilwig13 Effects13 of repeated hoopnetting13 on bonytail chub13 Journal of Freshwater13 Ecology13 20(4) 649-shy‐653

Pfeifer F M13 C Baker13 and M13 Montagne13 199913 Propagation13 facilities13 in the13 Grand Valley13 (24 Road13 Hatchery13 Horsethief13 Ponds and13 grow-shy‐out ponds) for captive rearing of

55

13

endangered13 fishes for the13 Upper Colorado13 River Basin13 Colorado13 River Recovery13 Program FY 99 annual project report Project No 29a13 US Fish and Wildlife Service13 Grand13 Junction13 5pp

Pfeifer F S Seversen and M Montagne 2003 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2003 annual reportProject No 29b13 US Fish and Wildlife13 Service Vernal13 4pp

Rabago-shy‐Castro J L Sanchez13 J G Perez-shy‐Castaneda R and13 Gonzalez-shy‐Gonzlez A 2006Effects of the prophylactic use of Romet-shy‐3013 and13 copper13 sulfate13 on growth13 condition13 and feeding13 indicies in13 channel13 catfish (Ictalurus punctatus) Aquaculture 253 343-shy‐349

Reinitz GL L E Orme and F N Hitzel 1979 Variations of body compositio and growth13 among strains of rainbow trout Transactions of the American Fisheries Society 108204-shy‐207

Ruppert13 J13 B P B Holden13 and P D Abate 1999 Age estimation and growth of razorbacksucker13 Xyrauchen texanus in Lake13 Mead Nevada Proceedings13 of the Desert FishesCouncil 3040

Schnoor K D and J Logan 2002 Operation and maintenance of JW Mumma nativeaquatic13 species restoration facility Colorado Colorado River Recovery Program FY2002 annual project report13 Project No 29d Colorado13 Division of Wildlife Alamosa3pp

Salisbury13 L13 1998 Factors13 affecting razorback13 sucker growth13 in Lake13 Mohave backwaters13 MS Thesis13 Unviersity13 of Nevada13 Las13 Vegas

Schooley J13 D13 and P C13 Marsh13 2007 Stocking of endangerdd13 razorback13 suckers13 in thelower Colorado River Basin13 over three decades 1974-shy‐2004 North American Journalof Fisheries Management 27 43-shy‐51

Severson S H H M Tyus and G B Haines 1992 An evaluation of feeds for raisingrazorback sucker Xyrauchen texanus Journal of Applied Aquaculture 155-shy‐65

Toney D P 1974 Observations13 on the13 propagation13 and13 rearing13 of two13 endangered species13 in a hatchery environment Proceedings of the Annual Conference of the Western13 Association of State Game and Fish Commissions 54 252-shy‐259

Tyus H M13 1998 Razorback sucker13 (Xyrauchen texanus) recovery plan13 University13 ofColorado Center for Limnology Boulder13 76 pages

Tyus H M13 and13 S H Severson 1990 Growth13 and13 survival of larval razorback suckers fedfive formulated diets The Progressive Fish Culturist 52197-shy‐200

56

13

Ulibarri M E 2003 Annual report fiscal year 2001 Dexter National Fish Hatchery13 andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 26 pages

Ulibarri M E 2003 Annual report fiscal year 2002 Dexter National Fish Hatchery andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 59 pages

USBR 2006 Lower13 Colorado13 River Multi-shy‐Species Conservation Program final fishaugmentation plan Boulder City 19 pp

USFWS 2002 Razorback sucker (Xyraouchen texanus) recovery goals Amendment andsupplement to the Razorback Sucker Recovery Plan13 US Fish and Wildlife Service13 Region 6 Denver13 Colorado

USFWS 1999 Annual report 1999 Ouray National Fish Hatchery Vernal 25pp

USFWS 2004 Management plan for the big-shy‐river13 fishes of the13 lower13 Colorado13 river basinamendment and supplement to the bonytail humpback chub Coloradopikeminnow and razorback sucker recovery plans

USFWS13 2005 Station13 profile13 of the13 Dexter13 National Fish Hatchery13 and Technology CenterUS Fish and Wildlife13 Service Dexter

Valdez R A P G Mangan R Smith and B Nilson 1982 Upper Colorado River fisheriesinvestigations13 inW H Miller J J Valentine D L Archer H M Tyus R A Valdezand L13 Kaeding13 editors13 Colorado River Fishery13 Project13 Part 2 Field13 investigations13 US Bureau of Reclamation Salt Lake City Utah

WBNFH 2004 Culture methods of the endangered razorback sucker Xyrauchen texanusUS Fish and Wildlife13 Service Willow Beach National Fish Hatchery13 8 pp

Ward D 2008 Effects of disease treatments on growth of razorback sucker ReportSubmitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 Inpartial fulfillment of work task C10 agreement number 06FG30039

Ward13 D13 M Childs and W Persons 2007 Factors13 affecting13 growth13 of razorback sucker13 (Xyrauchen texanus) in captivity Literature review and knowledge assessmentReport Submitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 In partial fulfillment of work task C10 agreement number 06FG30039

57

Appendices

Appendix 1 Survey Questions Survey of Razorback Sucker Culture in the

Southwestern United States

The enclosed survey is being distributed by the Arizona Game and Fish Department to razorback sucker culture facilities throughout

the Southwestern United States The purpose of this survey is to consolidate information regarding culture of this species so that

appropriate facility improvements can be considered for Bubbling Ponds Hatchery in Arizona Specifically we wish to increase

growth rate and production efficiency at the hatchery Information gathered in this survey will be summarized in a final report to US

Bureau of Reclamation in Boulder City NV and disseminated to all facilities that participate in the survey A workshop to discuss

the findings of this study as well as to share general information concerning razorback sucker culture will be organized by the

Arizona Game and Fish Department at the conclusion of this study and all participants will be invited

Thank you for taking the time to fill out this survey Please contact Mike Childs if you have questions or would like to discuss the

survey

Mike Childs

mchildssedonanet

(928) 639-1346

(928) 634-1279

Facility_____________________________________ Date___________________

Contact Phone _____________________________

ContactPerson_______________________________

Contact Email _______________________________

1 Water quality ranges at this culture facility

Season

Spring (Mar-May) Summer (Jun-Aug) Fall (Sept-Nov) Winter (Dec-Feb)

Temperature (C)

PH

DO (mgL)

PO4 (mgL)

TDS (mgL)

Hardness (mgL)

CaCO3

Pathogens

37

13

Marsh P C B R Kesner and C A Pacey 2005 Repatriation as s management strategy13 to13 conserve a critically13 imperiled fish species North American Journal of FisheriesManagement 25 547-shy‐556

Marsh P C and C A Pacey 2005 Immiscibility of native and non-shy‐native13 fishes Pages 59-shy‐63 inMJ13 Brouder13 CL13 Springer13 and CS13 Leon13 editors13 Proceedings of two13 symposia Restoring native fish to the lower Colorado River interactions of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 NV and13 Restoring natural13 function within a modified riverine environment the lower Colorado River13 July13 8-shy‐913 1998 Las Vegas NV US Fish and13 Wildlife13 Service Southwest Region AlbuquerqueNew Mexico

Marsh13 P13 C13 and J13 E Brooks13 198913 Predation13 by ictalurid catfishes as a deterrent13 toreestablishment of hatchery-shy‐reared13 razorback sucker The Southwestern Naturalist34188-shy‐195

Matthews R A 2005 Ichthyopthirus multifiliis Fouquet and Ichthyopthirosis infreshwater13 teleosts13 Pages13 159-shy‐218 in Advances in Parasitology volume 59 J RBaker R Muller D Rollinson (eds) Academic Press

McCarthy13 M S and W L Minckley 1987 Age estimation for razorback sucker (PiscesCatostomidae) from13 Lake Mohave Arizona and Nevada Journal of the Arizona-shy‐Nevada Academy of Science 2187-shy‐97

Minckley13 W L13 198313 Status of the razorback13 sucker13 Xyrauchen texanus (Abbot)13 in13 thelower Colorado River basin13 The Southwestern13 Naturalist13 28(2) 165-shy‐187

Minckley13 W L13 199113 Native fished of the Grand Canyon13 region an obituary13 Pages 124-shy‐177 in Colorado River ecology and dam13 management National Academy PressWashington13 DC

Minckley13 C13 O and M LaBarbara13 199913 Report13 on13 native fish grow-shy‐out facilities13 at Cibolaand Imperial National Wildlife Refuges 1993-shy‐199513 US Fish and13 Wildlife Service13 Parker Fishery Resources Office Parker Arizona

Modde13 T13 199613 Juvenile razorback sucker (Xyrauchen texanus) in a managed wetlandadjacent13 to the Green13 River13 Great13 Basin13 Naturalist13 56375-shy‐376

Modde T KP Burnham and E J Wick 1996 Population status of the razorback sucker13 inthe middle Green River (USA) Conservation13 biology 10 110-shy‐119

Modde13 T13 and G13 B Haines13 200513 Survival13 and growth of stocked razorback13 sucker andbonytail in multiple floodplain wetlands of the middle Green River under resetconditions13 Final report prepared for Upper Colorado13 River13 Basin RecoveryImplimentation Program US Fish and Wildlife Service Vernal 66 pp

54

13

Modde T Z H Bowen and D C Kitcheyan 2005 Spatial and temporal use of a spawning13 site in the middle Green River by wild hatchery-shy‐reared13 razorback suckers13 Transactions of the American Fisheries Society 134937-shy‐944

Mueller13 G13 199213 The native fish work13 group13 -shy‐ a multiagency endeavor to improve thestatus of the razorback sucker in Lake Mohave AZ-shy‐NV13 Proceedings of the DesertFishes Council 2369

Mueller G 1995 A program13 for maintaining the razorback sucker in Lake MohaveAmerican Fisheries Society Symposium 15127-shy‐135

Mueller13 G13 200613 Ecology of the bonytail13 and razorback13 sucker and the role of offchannelhabitats13 in their13 recovery Scientific13 investigations13 report 2006-shy‐5065 US GeologicalSurvey13 Denver

Mueller G and E Wick 1998 Testing of golf course ponds at Page Arizona for suitability13 as grow-shy‐out facility for razorback sucker using surplus fish from13 Ouray NationalFish Hatchery National Park Service US Fish and13 Wildlife13 Service and UtahDivision of Wildlife13 Resources 28 pages

Mueller13 G13 and T13 Burke13 200513 Survival13 of young13 razorback13 sucker (Xyrauchen texanus) inrelation to13 stocking rates13 (fishha)13 and13 in the presence13 or absence13 of predatorcommunities in Lake Mohave Arizona-shy‐Nevada13 Pages13 155-shy‐16313 in Proceedings of two13 symposia restoring native fish to the lower Colorado River interaction13 of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 Nevada US Fish and Wildlife13 Service Southwest Region Albuquerque New Mexico

Mueller13 G13 J13 Carpenter13 and P13 C13 Marsh13 200413 Cibola13 High Levee Pond annual report 2004US Geological Survey Fort Collins13 Science Center13 Colorado13 and Arizona StateUniversity Tempe 23 pages

Nesler T P K Christopherson J M Hudson C W McAda F Pfeifer and T E Czapla 2003An integrated stocking plan for razorback sucker bonytail and Colorado13 pikeminnow for the Upper Colorado River Endangered Fish Recovery ProgramAddendum13 to State Stocking Plans Upper Colorado River Basin Recovery13 Implementation Program 12 pp

Papoulias13 D and W13 L Minckley13 1992 Effects13 of foo availability13 on survival and growth13 of larval razorback suckers13 in ponds Transactions of the American Fisheries Society121340-shy‐355

Paukert13 C P D L Ward13 P J Sponholtz13 and K13 D Hilwig13 Effects13 of repeated hoopnetting13 on bonytail chub13 Journal of Freshwater13 Ecology13 20(4) 649-shy‐653

Pfeifer F M13 C Baker13 and M13 Montagne13 199913 Propagation13 facilities13 in the13 Grand Valley13 (24 Road13 Hatchery13 Horsethief13 Ponds and13 grow-shy‐out ponds) for captive rearing of

55

13

endangered13 fishes for the13 Upper Colorado13 River Basin13 Colorado13 River Recovery13 Program FY 99 annual project report Project No 29a13 US Fish and Wildlife Service13 Grand13 Junction13 5pp

Pfeifer F S Seversen and M Montagne 2003 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2003 annual reportProject No 29b13 US Fish and Wildlife13 Service Vernal13 4pp

Rabago-shy‐Castro J L Sanchez13 J G Perez-shy‐Castaneda R and13 Gonzalez-shy‐Gonzlez A 2006Effects of the prophylactic use of Romet-shy‐3013 and13 copper13 sulfate13 on growth13 condition13 and feeding13 indicies in13 channel13 catfish (Ictalurus punctatus) Aquaculture 253 343-shy‐349

Reinitz GL L E Orme and F N Hitzel 1979 Variations of body compositio and growth13 among strains of rainbow trout Transactions of the American Fisheries Society 108204-shy‐207

Ruppert13 J13 B P B Holden13 and P D Abate 1999 Age estimation and growth of razorbacksucker13 Xyrauchen texanus in Lake13 Mead Nevada Proceedings13 of the Desert FishesCouncil 3040

Schnoor K D and J Logan 2002 Operation and maintenance of JW Mumma nativeaquatic13 species restoration facility Colorado Colorado River Recovery Program FY2002 annual project report13 Project No 29d Colorado13 Division of Wildlife Alamosa3pp

Salisbury13 L13 1998 Factors13 affecting razorback13 sucker growth13 in Lake13 Mohave backwaters13 MS Thesis13 Unviersity13 of Nevada13 Las13 Vegas

Schooley J13 D13 and P C13 Marsh13 2007 Stocking of endangerdd13 razorback13 suckers13 in thelower Colorado River Basin13 over three decades 1974-shy‐2004 North American Journalof Fisheries Management 27 43-shy‐51

Severson S H H M Tyus and G B Haines 1992 An evaluation of feeds for raisingrazorback sucker Xyrauchen texanus Journal of Applied Aquaculture 155-shy‐65

Toney D P 1974 Observations13 on the13 propagation13 and13 rearing13 of two13 endangered species13 in a hatchery environment Proceedings of the Annual Conference of the Western13 Association of State Game and Fish Commissions 54 252-shy‐259

Tyus H M13 1998 Razorback sucker13 (Xyrauchen texanus) recovery plan13 University13 ofColorado Center for Limnology Boulder13 76 pages

Tyus H M13 and13 S H Severson 1990 Growth13 and13 survival of larval razorback suckers fedfive formulated diets The Progressive Fish Culturist 52197-shy‐200

56

13

Ulibarri M E 2003 Annual report fiscal year 2001 Dexter National Fish Hatchery13 andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 26 pages

Ulibarri M E 2003 Annual report fiscal year 2002 Dexter National Fish Hatchery andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 59 pages

USBR 2006 Lower13 Colorado13 River Multi-shy‐Species Conservation Program final fishaugmentation plan Boulder City 19 pp

USFWS 2002 Razorback sucker (Xyraouchen texanus) recovery goals Amendment andsupplement to the Razorback Sucker Recovery Plan13 US Fish and Wildlife Service13 Region 6 Denver13 Colorado

USFWS 1999 Annual report 1999 Ouray National Fish Hatchery Vernal 25pp

USFWS 2004 Management plan for the big-shy‐river13 fishes of the13 lower13 Colorado13 river basinamendment and supplement to the bonytail humpback chub Coloradopikeminnow and razorback sucker recovery plans

USFWS13 2005 Station13 profile13 of the13 Dexter13 National Fish Hatchery13 and Technology CenterUS Fish and Wildlife13 Service Dexter

Valdez R A P G Mangan R Smith and B Nilson 1982 Upper Colorado River fisheriesinvestigations13 inW H Miller J J Valentine D L Archer H M Tyus R A Valdezand L13 Kaeding13 editors13 Colorado River Fishery13 Project13 Part 2 Field13 investigations13 US Bureau of Reclamation Salt Lake City Utah

WBNFH 2004 Culture methods of the endangered razorback sucker Xyrauchen texanusUS Fish and Wildlife13 Service Willow Beach National Fish Hatchery13 8 pp

Ward D 2008 Effects of disease treatments on growth of razorback sucker ReportSubmitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 Inpartial fulfillment of work task C10 agreement number 06FG30039

Ward13 D13 M Childs and W Persons 2007 Factors13 affecting13 growth13 of razorback sucker13 (Xyrauchen texanus) in captivity Literature review and knowledge assessmentReport Submitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 In partial fulfillment of work task C10 agreement number 06FG30039

57

Appendices

Appendix 1 Survey Questions Survey of Razorback Sucker Culture in the

Southwestern United States

The enclosed survey is being distributed by the Arizona Game and Fish Department to razorback sucker culture facilities throughout

the Southwestern United States The purpose of this survey is to consolidate information regarding culture of this species so that

appropriate facility improvements can be considered for Bubbling Ponds Hatchery in Arizona Specifically we wish to increase

growth rate and production efficiency at the hatchery Information gathered in this survey will be summarized in a final report to US

Bureau of Reclamation in Boulder City NV and disseminated to all facilities that participate in the survey A workshop to discuss

the findings of this study as well as to share general information concerning razorback sucker culture will be organized by the

Arizona Game and Fish Department at the conclusion of this study and all participants will be invited

Thank you for taking the time to fill out this survey Please contact Mike Childs if you have questions or would like to discuss the

survey

Mike Childs

mchildssedonanet

(928) 639-1346

(928) 634-1279

Facility_____________________________________ Date___________________

Contact Phone _____________________________

ContactPerson_______________________________

Contact Email _______________________________

1 Water quality ranges at this culture facility

Season

Spring (Mar-May) Summer (Jun-Aug) Fall (Sept-Nov) Winter (Dec-Feb)

Temperature (C)

PH

DO (mgL)

PO4 (mgL)

TDS (mgL)

Hardness (mgL)

CaCO3

Pathogens

37

13

Modde T Z H Bowen and D C Kitcheyan 2005 Spatial and temporal use of a spawning13 site in the middle Green River by wild hatchery-shy‐reared13 razorback suckers13 Transactions of the American Fisheries Society 134937-shy‐944

Mueller13 G13 199213 The native fish work13 group13 -shy‐ a multiagency endeavor to improve thestatus of the razorback sucker in Lake Mohave AZ-shy‐NV13 Proceedings of the DesertFishes Council 2369

Mueller G 1995 A program13 for maintaining the razorback sucker in Lake MohaveAmerican Fisheries Society Symposium 15127-shy‐135

Mueller13 G13 200613 Ecology of the bonytail13 and razorback13 sucker and the role of offchannelhabitats13 in their13 recovery Scientific13 investigations13 report 2006-shy‐5065 US GeologicalSurvey13 Denver

Mueller G and E Wick 1998 Testing of golf course ponds at Page Arizona for suitability13 as grow-shy‐out facility for razorback sucker using surplus fish from13 Ouray NationalFish Hatchery National Park Service US Fish and13 Wildlife13 Service and UtahDivision of Wildlife13 Resources 28 pages

Mueller13 G13 and T13 Burke13 200513 Survival13 of young13 razorback13 sucker (Xyrauchen texanus) inrelation to13 stocking rates13 (fishha)13 and13 in the presence13 or absence13 of predatorcommunities in Lake Mohave Arizona-shy‐Nevada13 Pages13 155-shy‐16313 in Proceedings of two13 symposia restoring native fish to the lower Colorado River interaction13 of native13 and non-shy‐native13 fishes July13 13-shy‐1413 1999 Las13 Vegas13 Nevada US Fish and Wildlife13 Service Southwest Region Albuquerque New Mexico

Mueller13 G13 J13 Carpenter13 and P13 C13 Marsh13 200413 Cibola13 High Levee Pond annual report 2004US Geological Survey Fort Collins13 Science Center13 Colorado13 and Arizona StateUniversity Tempe 23 pages

Nesler T P K Christopherson J M Hudson C W McAda F Pfeifer and T E Czapla 2003An integrated stocking plan for razorback sucker bonytail and Colorado13 pikeminnow for the Upper Colorado River Endangered Fish Recovery ProgramAddendum13 to State Stocking Plans Upper Colorado River Basin Recovery13 Implementation Program 12 pp

Papoulias13 D and W13 L Minckley13 1992 Effects13 of foo availability13 on survival and growth13 of larval razorback suckers13 in ponds Transactions of the American Fisheries Society121340-shy‐355

Paukert13 C P D L Ward13 P J Sponholtz13 and K13 D Hilwig13 Effects13 of repeated hoopnetting13 on bonytail chub13 Journal of Freshwater13 Ecology13 20(4) 649-shy‐653

Pfeifer F M13 C Baker13 and M13 Montagne13 199913 Propagation13 facilities13 in the13 Grand Valley13 (24 Road13 Hatchery13 Horsethief13 Ponds and13 grow-shy‐out ponds) for captive rearing of

55

13

endangered13 fishes for the13 Upper Colorado13 River Basin13 Colorado13 River Recovery13 Program FY 99 annual project report Project No 29a13 US Fish and Wildlife Service13 Grand13 Junction13 5pp

Pfeifer F S Seversen and M Montagne 2003 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2003 annual reportProject No 29b13 US Fish and Wildlife13 Service Vernal13 4pp

Rabago-shy‐Castro J L Sanchez13 J G Perez-shy‐Castaneda R and13 Gonzalez-shy‐Gonzlez A 2006Effects of the prophylactic use of Romet-shy‐3013 and13 copper13 sulfate13 on growth13 condition13 and feeding13 indicies in13 channel13 catfish (Ictalurus punctatus) Aquaculture 253 343-shy‐349

Reinitz GL L E Orme and F N Hitzel 1979 Variations of body compositio and growth13 among strains of rainbow trout Transactions of the American Fisheries Society 108204-shy‐207

Ruppert13 J13 B P B Holden13 and P D Abate 1999 Age estimation and growth of razorbacksucker13 Xyrauchen texanus in Lake13 Mead Nevada Proceedings13 of the Desert FishesCouncil 3040

Schnoor K D and J Logan 2002 Operation and maintenance of JW Mumma nativeaquatic13 species restoration facility Colorado Colorado River Recovery Program FY2002 annual project report13 Project No 29d Colorado13 Division of Wildlife Alamosa3pp

Salisbury13 L13 1998 Factors13 affecting razorback13 sucker growth13 in Lake13 Mohave backwaters13 MS Thesis13 Unviersity13 of Nevada13 Las13 Vegas

Schooley J13 D13 and P C13 Marsh13 2007 Stocking of endangerdd13 razorback13 suckers13 in thelower Colorado River Basin13 over three decades 1974-shy‐2004 North American Journalof Fisheries Management 27 43-shy‐51

Severson S H H M Tyus and G B Haines 1992 An evaluation of feeds for raisingrazorback sucker Xyrauchen texanus Journal of Applied Aquaculture 155-shy‐65

Toney D P 1974 Observations13 on the13 propagation13 and13 rearing13 of two13 endangered species13 in a hatchery environment Proceedings of the Annual Conference of the Western13 Association of State Game and Fish Commissions 54 252-shy‐259

Tyus H M13 1998 Razorback sucker13 (Xyrauchen texanus) recovery plan13 University13 ofColorado Center for Limnology Boulder13 76 pages

Tyus H M13 and13 S H Severson 1990 Growth13 and13 survival of larval razorback suckers fedfive formulated diets The Progressive Fish Culturist 52197-shy‐200

56

13

Ulibarri M E 2003 Annual report fiscal year 2001 Dexter National Fish Hatchery13 andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 26 pages

Ulibarri M E 2003 Annual report fiscal year 2002 Dexter National Fish Hatchery andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 59 pages

USBR 2006 Lower13 Colorado13 River Multi-shy‐Species Conservation Program final fishaugmentation plan Boulder City 19 pp

USFWS 2002 Razorback sucker (Xyraouchen texanus) recovery goals Amendment andsupplement to the Razorback Sucker Recovery Plan13 US Fish and Wildlife Service13 Region 6 Denver13 Colorado

USFWS 1999 Annual report 1999 Ouray National Fish Hatchery Vernal 25pp

USFWS 2004 Management plan for the big-shy‐river13 fishes of the13 lower13 Colorado13 river basinamendment and supplement to the bonytail humpback chub Coloradopikeminnow and razorback sucker recovery plans

USFWS13 2005 Station13 profile13 of the13 Dexter13 National Fish Hatchery13 and Technology CenterUS Fish and Wildlife13 Service Dexter

Valdez R A P G Mangan R Smith and B Nilson 1982 Upper Colorado River fisheriesinvestigations13 inW H Miller J J Valentine D L Archer H M Tyus R A Valdezand L13 Kaeding13 editors13 Colorado River Fishery13 Project13 Part 2 Field13 investigations13 US Bureau of Reclamation Salt Lake City Utah

WBNFH 2004 Culture methods of the endangered razorback sucker Xyrauchen texanusUS Fish and Wildlife13 Service Willow Beach National Fish Hatchery13 8 pp

Ward D 2008 Effects of disease treatments on growth of razorback sucker ReportSubmitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 Inpartial fulfillment of work task C10 agreement number 06FG30039

Ward13 D13 M Childs and W Persons 2007 Factors13 affecting13 growth13 of razorback sucker13 (Xyrauchen texanus) in captivity Literature review and knowledge assessmentReport Submitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 In partial fulfillment of work task C10 agreement number 06FG30039

57

Appendices

Appendix 1 Survey Questions Survey of Razorback Sucker Culture in the

Southwestern United States

The enclosed survey is being distributed by the Arizona Game and Fish Department to razorback sucker culture facilities throughout

the Southwestern United States The purpose of this survey is to consolidate information regarding culture of this species so that

appropriate facility improvements can be considered for Bubbling Ponds Hatchery in Arizona Specifically we wish to increase

growth rate and production efficiency at the hatchery Information gathered in this survey will be summarized in a final report to US

Bureau of Reclamation in Boulder City NV and disseminated to all facilities that participate in the survey A workshop to discuss

the findings of this study as well as to share general information concerning razorback sucker culture will be organized by the

Arizona Game and Fish Department at the conclusion of this study and all participants will be invited

Thank you for taking the time to fill out this survey Please contact Mike Childs if you have questions or would like to discuss the

survey

Mike Childs

mchildssedonanet

(928) 639-1346

(928) 634-1279

Facility_____________________________________ Date___________________

Contact Phone _____________________________

ContactPerson_______________________________

Contact Email _______________________________

1 Water quality ranges at this culture facility

Season

Spring (Mar-May) Summer (Jun-Aug) Fall (Sept-Nov) Winter (Dec-Feb)

Temperature (C)

PH

DO (mgL)

PO4 (mgL)

TDS (mgL)

Hardness (mgL)

CaCO3

Pathogens

37

13

endangered13 fishes for the13 Upper Colorado13 River Basin13 Colorado13 River Recovery13 Program FY 99 annual project report Project No 29a13 US Fish and Wildlife Service13 Grand13 Junction13 5pp

Pfeifer F S Seversen and M Montagne 2003 Operation and maintenance of OurayNational Fish Hatchery Colorado River Recovery Program FY 2003 annual reportProject No 29b13 US Fish and Wildlife13 Service Vernal13 4pp

Rabago-shy‐Castro J L Sanchez13 J G Perez-shy‐Castaneda R and13 Gonzalez-shy‐Gonzlez A 2006Effects of the prophylactic use of Romet-shy‐3013 and13 copper13 sulfate13 on growth13 condition13 and feeding13 indicies in13 channel13 catfish (Ictalurus punctatus) Aquaculture 253 343-shy‐349

Reinitz GL L E Orme and F N Hitzel 1979 Variations of body compositio and growth13 among strains of rainbow trout Transactions of the American Fisheries Society 108204-shy‐207

Ruppert13 J13 B P B Holden13 and P D Abate 1999 Age estimation and growth of razorbacksucker13 Xyrauchen texanus in Lake13 Mead Nevada Proceedings13 of the Desert FishesCouncil 3040

Schnoor K D and J Logan 2002 Operation and maintenance of JW Mumma nativeaquatic13 species restoration facility Colorado Colorado River Recovery Program FY2002 annual project report13 Project No 29d Colorado13 Division of Wildlife Alamosa3pp

Salisbury13 L13 1998 Factors13 affecting razorback13 sucker growth13 in Lake13 Mohave backwaters13 MS Thesis13 Unviersity13 of Nevada13 Las13 Vegas

Schooley J13 D13 and P C13 Marsh13 2007 Stocking of endangerdd13 razorback13 suckers13 in thelower Colorado River Basin13 over three decades 1974-shy‐2004 North American Journalof Fisheries Management 27 43-shy‐51

Severson S H H M Tyus and G B Haines 1992 An evaluation of feeds for raisingrazorback sucker Xyrauchen texanus Journal of Applied Aquaculture 155-shy‐65

Toney D P 1974 Observations13 on the13 propagation13 and13 rearing13 of two13 endangered species13 in a hatchery environment Proceedings of the Annual Conference of the Western13 Association of State Game and Fish Commissions 54 252-shy‐259

Tyus H M13 1998 Razorback sucker13 (Xyrauchen texanus) recovery plan13 University13 ofColorado Center for Limnology Boulder13 76 pages

Tyus H M13 and13 S H Severson 1990 Growth13 and13 survival of larval razorback suckers fedfive formulated diets The Progressive Fish Culturist 52197-shy‐200

56

13

Ulibarri M E 2003 Annual report fiscal year 2001 Dexter National Fish Hatchery13 andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 26 pages

Ulibarri M E 2003 Annual report fiscal year 2002 Dexter National Fish Hatchery andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 59 pages

USBR 2006 Lower13 Colorado13 River Multi-shy‐Species Conservation Program final fishaugmentation plan Boulder City 19 pp

USFWS 2002 Razorback sucker (Xyraouchen texanus) recovery goals Amendment andsupplement to the Razorback Sucker Recovery Plan13 US Fish and Wildlife Service13 Region 6 Denver13 Colorado

USFWS 1999 Annual report 1999 Ouray National Fish Hatchery Vernal 25pp

USFWS 2004 Management plan for the big-shy‐river13 fishes of the13 lower13 Colorado13 river basinamendment and supplement to the bonytail humpback chub Coloradopikeminnow and razorback sucker recovery plans

USFWS13 2005 Station13 profile13 of the13 Dexter13 National Fish Hatchery13 and Technology CenterUS Fish and Wildlife13 Service Dexter

Valdez R A P G Mangan R Smith and B Nilson 1982 Upper Colorado River fisheriesinvestigations13 inW H Miller J J Valentine D L Archer H M Tyus R A Valdezand L13 Kaeding13 editors13 Colorado River Fishery13 Project13 Part 2 Field13 investigations13 US Bureau of Reclamation Salt Lake City Utah

WBNFH 2004 Culture methods of the endangered razorback sucker Xyrauchen texanusUS Fish and Wildlife13 Service Willow Beach National Fish Hatchery13 8 pp

Ward D 2008 Effects of disease treatments on growth of razorback sucker ReportSubmitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 Inpartial fulfillment of work task C10 agreement number 06FG30039

Ward13 D13 M Childs and W Persons 2007 Factors13 affecting13 growth13 of razorback sucker13 (Xyrauchen texanus) in captivity Literature review and knowledge assessmentReport Submitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 In partial fulfillment of work task C10 agreement number 06FG30039

57

Appendices

Appendix 1 Survey Questions Survey of Razorback Sucker Culture in the

Southwestern United States

The enclosed survey is being distributed by the Arizona Game and Fish Department to razorback sucker culture facilities throughout

the Southwestern United States The purpose of this survey is to consolidate information regarding culture of this species so that

appropriate facility improvements can be considered for Bubbling Ponds Hatchery in Arizona Specifically we wish to increase

growth rate and production efficiency at the hatchery Information gathered in this survey will be summarized in a final report to US

Bureau of Reclamation in Boulder City NV and disseminated to all facilities that participate in the survey A workshop to discuss

the findings of this study as well as to share general information concerning razorback sucker culture will be organized by the

Arizona Game and Fish Department at the conclusion of this study and all participants will be invited

Thank you for taking the time to fill out this survey Please contact Mike Childs if you have questions or would like to discuss the

survey

Mike Childs

mchildssedonanet

(928) 639-1346

(928) 634-1279

Facility_____________________________________ Date___________________

Contact Phone _____________________________

ContactPerson_______________________________

Contact Email _______________________________

1 Water quality ranges at this culture facility

Season

Spring (Mar-May) Summer (Jun-Aug) Fall (Sept-Nov) Winter (Dec-Feb)

Temperature (C)

PH

DO (mgL)

PO4 (mgL)

TDS (mgL)

Hardness (mgL)

CaCO3

Pathogens

37

13

Ulibarri M E 2003 Annual report fiscal year 2001 Dexter National Fish Hatchery13 andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 26 pages

Ulibarri M E 2003 Annual report fiscal year 2002 Dexter National Fish Hatchery andTechnology13 Center13 US Fish and13 Wildlife13 Service Dexter13 New Mexico13 59 pages

USBR 2006 Lower13 Colorado13 River Multi-shy‐Species Conservation Program final fishaugmentation plan Boulder City 19 pp

USFWS 2002 Razorback sucker (Xyraouchen texanus) recovery goals Amendment andsupplement to the Razorback Sucker Recovery Plan13 US Fish and Wildlife Service13 Region 6 Denver13 Colorado

USFWS 1999 Annual report 1999 Ouray National Fish Hatchery Vernal 25pp

USFWS 2004 Management plan for the big-shy‐river13 fishes of the13 lower13 Colorado13 river basinamendment and supplement to the bonytail humpback chub Coloradopikeminnow and razorback sucker recovery plans

USFWS13 2005 Station13 profile13 of the13 Dexter13 National Fish Hatchery13 and Technology CenterUS Fish and Wildlife13 Service Dexter

Valdez R A P G Mangan R Smith and B Nilson 1982 Upper Colorado River fisheriesinvestigations13 inW H Miller J J Valentine D L Archer H M Tyus R A Valdezand L13 Kaeding13 editors13 Colorado River Fishery13 Project13 Part 2 Field13 investigations13 US Bureau of Reclamation Salt Lake City Utah

WBNFH 2004 Culture methods of the endangered razorback sucker Xyrauchen texanusUS Fish and Wildlife13 Service Willow Beach National Fish Hatchery13 8 pp

Ward D 2008 Effects of disease treatments on growth of razorback sucker ReportSubmitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 Inpartial fulfillment of work task C10 agreement number 06FG30039

Ward13 D13 M Childs and W Persons 2007 Factors13 affecting13 growth13 of razorback sucker13 (Xyrauchen texanus) in captivity Literature review and knowledge assessmentReport Submitted to The Lower Colorado River Multi-shy‐Species Conservation Program13 In partial fulfillment of work task C10 agreement number 06FG30039

57

Appendices

Appendix 1 Survey Questions Survey of Razorback Sucker Culture in the

Southwestern United States

The enclosed survey is being distributed by the Arizona Game and Fish Department to razorback sucker culture facilities throughout

the Southwestern United States The purpose of this survey is to consolidate information regarding culture of this species so that

appropriate facility improvements can be considered for Bubbling Ponds Hatchery in Arizona Specifically we wish to increase

growth rate and production efficiency at the hatchery Information gathered in this survey will be summarized in a final report to US

Bureau of Reclamation in Boulder City NV and disseminated to all facilities that participate in the survey A workshop to discuss

the findings of this study as well as to share general information concerning razorback sucker culture will be organized by the

Arizona Game and Fish Department at the conclusion of this study and all participants will be invited

Thank you for taking the time to fill out this survey Please contact Mike Childs if you have questions or would like to discuss the

survey

Mike Childs

mchildssedonanet

(928) 639-1346

(928) 634-1279

Facility_____________________________________ Date___________________

Contact Phone _____________________________

ContactPerson_______________________________

Contact Email _______________________________

1 Water quality ranges at this culture facility

Season

Spring (Mar-May) Summer (Jun-Aug) Fall (Sept-Nov) Winter (Dec-Feb)

Temperature (C)

PH

DO (mgL)

PO4 (mgL)

TDS (mgL)

Hardness (mgL)

CaCO3

Pathogens

37

Appendices

Appendix 1 Survey Questions Survey of Razorback Sucker Culture in the

Southwestern United States

The enclosed survey is being distributed by the Arizona Game and Fish Department to razorback sucker culture facilities throughout

the Southwestern United States The purpose of this survey is to consolidate information regarding culture of this species so that

appropriate facility improvements can be considered for Bubbling Ponds Hatchery in Arizona Specifically we wish to increase

growth rate and production efficiency at the hatchery Information gathered in this survey will be summarized in a final report to US

Bureau of Reclamation in Boulder City NV and disseminated to all facilities that participate in the survey A workshop to discuss

the findings of this study as well as to share general information concerning razorback sucker culture will be organized by the

Arizona Game and Fish Department at the conclusion of this study and all participants will be invited

Thank you for taking the time to fill out this survey Please contact Mike Childs if you have questions or would like to discuss the

survey

Mike Childs

mchildssedonanet

(928) 639-1346

(928) 634-1279

Facility_____________________________________ Date___________________

Contact Phone _____________________________

ContactPerson_______________________________

Contact Email _______________________________

1 Water quality ranges at this culture facility

Season

Spring (Mar-May) Summer (Jun-Aug) Fall (Sept-Nov) Winter (Dec-Feb)

Temperature (C)

PH

DO (mgL)

PO4 (mgL)

TDS (mgL)

Hardness (mgL)

CaCO3

Pathogens

37

2 What is the water source (spring well river etc) and is the source protected from fish and pathogen introduction

3 Holding facilities available for razorback sucker

Type1 N Vol (ft3) Flow (gpm)

Max weight 4 inch fish

Max weight 6 inch fish

Max weight 8 inch fish

Max weight

10inch fish

Max weight

12inch fish

Max weight

14inch fish

1Type (EP) denotes earthen pond (LP) lined pond (LR) linear raceway (CT) circular tank and (AQ) aquarium

4 Do you try to maintain density and flow indices at a constant value If not what do you think the ideal density and flow indices

are for your facility

5 Feeding and growth of razorback sucker

Average Fish

Length Food and Quantity (g foodkg Fish)1

Average Growth

Rate (inmonth)

Larvae

2 inch

4 inch

6 inch

8 inch

10 inch

12 inch

14 inch

16 inch 1Food types include TS (trout starter) T1-5 (trout chow 1 ndash5) CS (catfish starter) C1-5 (catfish 1-5) RS (razorback starter) R1-5 (razorback 1-5) A (Artemia) K (krill) B (bloodworm) include notes for other food types6 What factors do you think would be most important in improving growth rate of razorback sucker at your facility Please discuss factors such as water quality (temperature oxygen pH nitrogen) fish density flow rate food type and quantity photoperiod reproductive condition etc as they pertain to your facility

7 Do you have problems with razorback stunting (or variable growth rates) at your facility What factor(s) do you think contribute

most to stunted growth of razorback sucker at your facility

8 Do you think that natural variation in growth rate of razorback sucker can be overcome by manipulating any factors at your

facility If so at what cost (monetary loss of genetic diversity etc)

9 Based on your answers to the above questions what do you think the ideal culture situation would be for razorback sucker if the

primary management goal was to improve growth rate (culture container water conditions feed etc)

10 Do you have any data (electronic format) that you would be willing to share that could be used to compare growth rates of

razorback sucker at the various culture facilities in the Southwestern United States If so accompanying data on water

quality fish density etc would add greatly to such a dataset This information will be summarized and provided to all

razorback culturists who participate in this survey

11 Please provide a general history of razorback sucker culture at your facility (years of culture strategies attempted) Please include

successes and failures (with details regarding holding conditions flow etc) and provide an explanation for what has

worked and what has not

38

Appendix 2 Follow-up Surveys Questions about existing facilities

1 What is the biggest difficulty at your facility in growing subadult razorback suckers to the target size (300 mm)

2 What diseases are most problematic at your facility

3 How do you treat for these diseases

4 Do you have a target stocking density for ponds What is it

5 What do you feed your fish How many times a day do you feed What of body weight

6 How often do you sortor grade fish during the year How are the fish graded

7 How do you harvest fish Drain ponds completely seine a lowered pond fyke nets hoop nets etc

8 How big are the fish that you normally start with How big approximately are your fish at the end of the first year How long approximately does it take you to grow fish to the target size (300 mm)

9 Do you have temperature data or growth rate data for your facility and would you be willing to share it OR

10 Approx when does the mean water temp reach 20degC at your facility Spring - Month When in the fall does it begin to drop below 20degC

Hypothetical questions - Opinions as to what you think would work best

1 In your opinion what would be the best type of facility for growing out subadult RZB (100 mm to 500 mm)

Raceways Circular tanks Ponds Other

2 If using ponds what size pond would be most effective By surface area 110 acre 5 acre 1 acre 10 acres etc

3 What would be the ideal depth Average depth Max depth

4 Would the pond be lined or unlined 5 Would you grade or sort fish and how often

39

Appendix 3 Tabulated Survey Results

Survey Participants

Name Facility Telephone number Agency Frank Agyagos Bubbling Ponds 928-634-4466 Arizona Game amp Fish Dave Billingsly Bubbling Ponds 928-634-4466 Arizona Game amp Fish Dave Hampton Dexter 505-734-5910 US Fish amp Wildlife Service Manuel Ulibarri Dexter 505-734-5910 US Fish amp Wildlife Service Thad Bingham Grand Junction 970-245-9319 US Fish amp Wildlife Service Brian Scheer Grand Junction 970-245-9319 US Fish amp Wildlife Service Mike Montagne Ouray 435-789-0351 US Fish amp Wildlife Service Sam Pollock Ouray 435-789-0351 US Fish amp Wildlife Service John Scott Willow Beach 928-767-3456 US Fish amp Wildlife Service Geno Sprofera Willow Beach 928-767-3456 US Fish amp Wildlife Service Robert Krapfel Achii Hanyo 928-853-1673 US Fish amp Wildlife Service Deborah Herndon Lake Mead 702-486-6740 Nevada Dept of Wildlife Quent Bradwisch Wahweep 435-675-3714 Utah Division of wildlife Resources Annette Morgan Hualapai ponds 928-769-2255 Hualapai Division of Natural Resources Joe Marrinan Mumma 719-587-3392 Colorado Division of Wildlife Grant Webber Uvalde 830-278-2419 US Fish amp Wildlife Service

Questions about existing facilities and practices

What is the biggest difficulty at your facility in growing razorback suckers to the target size

8

6

4

2

0

Num

ber o

f Res

pons

es

Temperature Water Quality Space Issues Diseases Predation Other

40

Which diseases are the most problematic at your facility N

umbe

r of R

espo

nses

0

2

4

6

Num

ber o

f Res

pons

es

0

1

2

3

4

5

6

None Ich Costia Bacterial trichodina Lernea

How often do you currently sortgrade fish

Only at harvest 2-3 times a year Every 2 months Other

41

HypotheticalOpinion Questions

What would be the best type of facility for growing-out subadult razorback suckers

Raceways Ponds Circular tanks Other

Num

ber o

f Res

pons

es

0

2

4

6

8

10

12

Other = combination of ponds initially and then grow-out in raceways

What size of pond would be best for growing-out subadult razorback suckers

Num

ber o

f Res

pons

es

0

1

2

3

4

5

01 025 05 1 gt 1 acre

Surface Acres

42

• Growth of Razorback Sucker (Xyrauchen texanus) at Bubbling Ponds Fish Hatchery - cover
• Steering Committee Members
• Title Page
• Table of Contents
• Executive Summary
• Main Text
• Literature Cited
• Appendices

Appendix 2 Follow-up Surveys Questions about existing facilities

1 What is the biggest difficulty at your facility in growing subadult razorback suckers to the target size (300 mm)

2 What diseases are most problematic at your facility

3 How do you treat for these diseases

4 Do you have a target stocking density for ponds What is it

5 What do you feed your fish How many times a day do you feed What of body weight

6 How often do you sortor grade fish during the year How are the fish graded

7 How do you harvest fish Drain ponds completely seine a lowered pond fyke nets hoop nets etc

8 How big are the fish that you normally start with How big approximately are your fish at the end of the first year How long approximately does it take you to grow fish to the target size (300 mm)

9 Do you have temperature data or growth rate data for your facility and would you be willing to share it OR

10 Approx when does the mean water temp reach 20degC at your facility Spring - Month When in the fall does it begin to drop below 20degC

Hypothetical questions - Opinions as to what you think would work best

1 In your opinion what would be the best type of facility for growing out subadult RZB (100 mm to 500 mm)

Raceways Circular tanks Ponds Other

2 If using ponds what size pond would be most effective By surface area 110 acre 5 acre 1 acre 10 acres etc

3 What would be the ideal depth Average depth Max depth

4 Would the pond be lined or unlined 5 Would you grade or sort fish and how often

39

Appendix 3 Tabulated Survey Results

Survey Participants

Name Facility Telephone number Agency Frank Agyagos Bubbling Ponds 928-634-4466 Arizona Game amp Fish Dave Billingsly Bubbling Ponds 928-634-4466 Arizona Game amp Fish Dave Hampton Dexter 505-734-5910 US Fish amp Wildlife Service Manuel Ulibarri Dexter 505-734-5910 US Fish amp Wildlife Service Thad Bingham Grand Junction 970-245-9319 US Fish amp Wildlife Service Brian Scheer Grand Junction 970-245-9319 US Fish amp Wildlife Service Mike Montagne Ouray 435-789-0351 US Fish amp Wildlife Service Sam Pollock Ouray 435-789-0351 US Fish amp Wildlife Service John Scott Willow Beach 928-767-3456 US Fish amp Wildlife Service Geno Sprofera Willow Beach 928-767-3456 US Fish amp Wildlife Service Robert Krapfel Achii Hanyo 928-853-1673 US Fish amp Wildlife Service Deborah Herndon Lake Mead 702-486-6740 Nevada Dept of Wildlife Quent Bradwisch Wahweep 435-675-3714 Utah Division of wildlife Resources Annette Morgan Hualapai ponds 928-769-2255 Hualapai Division of Natural Resources Joe Marrinan Mumma 719-587-3392 Colorado Division of Wildlife Grant Webber Uvalde 830-278-2419 US Fish amp Wildlife Service

Questions about existing facilities and practices

What is the biggest difficulty at your facility in growing razorback suckers to the target size

8

6

4

2

0

Num

ber o

f Res

pons

es

Temperature Water Quality Space Issues Diseases Predation Other

40

Which diseases are the most problematic at your facility N

umbe

r of R

espo

nses

0

2

4

6

Num

ber o

f Res

pons

es

0

1

2

3

4

5

6

None Ich Costia Bacterial trichodina Lernea

How often do you currently sortgrade fish

Only at harvest 2-3 times a year Every 2 months Other

41

HypotheticalOpinion Questions

What would be the best type of facility for growing-out subadult razorback suckers

Raceways Ponds Circular tanks Other

Num

ber o

f Res

pons

es

0

2

4

6

8

10

12

Other = combination of ponds initially and then grow-out in raceways

What size of pond would be best for growing-out subadult razorback suckers

Num

ber o

f Res

pons

es

0

1

2

3

4

5

01 025 05 1 gt 1 acre

Surface Acres

42

• Growth of Razorback Sucker (Xyrauchen texanus) at Bubbling Ponds Fish Hatchery - cover
• Steering Committee Members
• Title Page
• Table of Contents
• Executive Summary
• Main Text
• Literature Cited
• Appendices

Appendix 3 Tabulated Survey Results

Survey Participants

Name Facility Telephone number Agency Frank Agyagos Bubbling Ponds 928-634-4466 Arizona Game amp Fish Dave Billingsly Bubbling Ponds 928-634-4466 Arizona Game amp Fish Dave Hampton Dexter 505-734-5910 US Fish amp Wildlife Service Manuel Ulibarri Dexter 505-734-5910 US Fish amp Wildlife Service Thad Bingham Grand Junction 970-245-9319 US Fish amp Wildlife Service Brian Scheer Grand Junction 970-245-9319 US Fish amp Wildlife Service Mike Montagne Ouray 435-789-0351 US Fish amp Wildlife Service Sam Pollock Ouray 435-789-0351 US Fish amp Wildlife Service John Scott Willow Beach 928-767-3456 US Fish amp Wildlife Service Geno Sprofera Willow Beach 928-767-3456 US Fish amp Wildlife Service Robert Krapfel Achii Hanyo 928-853-1673 US Fish amp Wildlife Service Deborah Herndon Lake Mead 702-486-6740 Nevada Dept of Wildlife Quent Bradwisch Wahweep 435-675-3714 Utah Division of wildlife Resources Annette Morgan Hualapai ponds 928-769-2255 Hualapai Division of Natural Resources Joe Marrinan Mumma 719-587-3392 Colorado Division of Wildlife Grant Webber Uvalde 830-278-2419 US Fish amp Wildlife Service

Questions about existing facilities and practices

What is the biggest difficulty at your facility in growing razorback suckers to the target size

8

6

4

2

0

Num

ber o

f Res

pons

es

Temperature Water Quality Space Issues Diseases Predation Other

40

Which diseases are the most problematic at your facility N

umbe

r of R

espo

nses

0

2

4

6

Num

ber o

f Res

pons

es

0

1

2

3

4

5

6

None Ich Costia Bacterial trichodina Lernea

How often do you currently sortgrade fish

Only at harvest 2-3 times a year Every 2 months Other

41

HypotheticalOpinion Questions

What would be the best type of facility for growing-out subadult razorback suckers

Raceways Ponds Circular tanks Other

Num

ber o

f Res

pons

es

0

2

4

6

8

10

12

Other = combination of ponds initially and then grow-out in raceways

What size of pond would be best for growing-out subadult razorback suckers

Num

ber o

f Res

pons

es

0

1

2

3

4

5

01 025 05 1 gt 1 acre

Surface Acres

42

• Growth of Razorback Sucker (Xyrauchen texanus) at Bubbling Ponds Fish Hatchery - cover
• Steering Committee Members
• Title Page
• Table of Contents
• Executive Summary
• Main Text
• Literature Cited
• Appendices

Which diseases are the most problematic at your facility N

umbe

r of R

espo

nses

0

2

4

6

Num

ber o

f Res

pons

es

0

1

2

3

4

5

6

None Ich Costia Bacterial trichodina Lernea

How often do you currently sortgrade fish

Only at harvest 2-3 times a year Every 2 months Other

41

HypotheticalOpinion Questions

What would be the best type of facility for growing-out subadult razorback suckers

Raceways Ponds Circular tanks Other

Num

ber o

f Res

pons

es

0

2

4

6

8

10

12

Other = combination of ponds initially and then grow-out in raceways

What size of pond would be best for growing-out subadult razorback suckers

Num

ber o

f Res

pons

es

0

1

2

3

4

5

01 025 05 1 gt 1 acre

Surface Acres

42

• Growth of Razorback Sucker (Xyrauchen texanus) at Bubbling Ponds Fish Hatchery - cover
• Steering Committee Members
• Title Page
• Table of Contents
• Executive Summary
• Main Text
• Literature Cited
• Appendices

HypotheticalOpinion Questions

What would be the best type of facility for growing-out subadult razorback suckers

Raceways Ponds Circular tanks Other

Num

ber o

f Res

pons

es

0

2

4

6

8

10

12

Other = combination of ponds initially and then grow-out in raceways

What size of pond would be best for growing-out subadult razorback suckers

Num

ber o

f Res

pons

es

0

1

2

3

4

5

01 025 05 1 gt 1 acre

Surface Acres

42

• Growth of Razorback Sucker (Xyrauchen texanus) at Bubbling Ponds Fish Hatchery - cover
• Steering Committee Members
• Title Page
• Table of Contents
• Executive Summary
• Main Text
• Literature Cited
• Appendices