Natural Reproductive Success and Demographic Effects of Hatchery-Origin

Steelhead in Abernathy Creek, Washington

Abernathy Fish Technology CenterU.S. Fish and Wildlife Service

Traditional Hatchery Procedures

An Alternative

• Collect & rear natural-origin juveniles to sexual maturity

1) Large #s of fish & low effect on population

2) High Genetic Diversity

Objectives

1) Assess the overall effects of hatchery supplementation relative to control streams

2) Determine the natural reproductive success of hatchery-origin and natural-origin steelhead

Comprehensive Approach

Hatchery Management & Procedures

Cost/Benefit Analysis

Direct application to hatcheries with

conservation goals

Hatchery Production

EcologicalBehavioral

Physiological

Suggests means to manipulate

Reproductive Success

Elucidate Mechanisms

GeneticsParentage

Hatchery vs. Natural

Does it work & direction

1999 2000 2001

    Mean   Mean SD   Mean SD

Adult Steelhead

Male Length (mm)

410 52 420 62 447 50

Female Length (mm)

402 58 403 60 424 55

  Fecundity 1313 522   1425 569   1711 626

Hatchery Reared Adult Steelhead

Juvenile Collection Year

Hatchery Methods and Procedures Prior to Release

CWT and AD clipped (subset PIT tagged)

Genotyped

Gill Biopsies

Steelhead Release

N = 20,000 Hatchery origin fish per yearFish released at 3 different times (blocks)

Hatchery and Natural Emigration

Collaborator: IMW Project & WDFW

Natural Origin Smolt Production

Coho salmon

Year

2000 2001 2002 2003 2004 2005 20060

4000

8000

12000

Cutthroat trout

Nu

mb

er o

f F

ish

0

4000

8000

12000

Steelhead

0

4000

8000

12000AbernathyMill Germany

Smolt Emigration

Hatchery 2003n=415

0

8

16

Hatchery 2004n=624

Fis

h C

ross

ing

An

ten

na

(%)

0

8

16

Hatchery 2005n=683

Month

0

8

16

Natural 2003n=380

Natural 2004n=533

Natural 2005n=311

11 12 01 02 03 04 05 06 07 08 09 10 11 12 01 02 03 04 05 06 07 08 09 10

Median Travel DateHatchery 2003Median date: 5/3/03

0

50

100

Hatchery 2004Median date: 4/29/04

Fis

h D

etec

ted

at

An

ten

na

(%)

0

50

100

Hatchery 2005Median date: 5/5/05

Month

0

50

100

Natural 2003Median date: 4/21/03

Natural 2004Median date: 4/30/04

Natural 2005Median date: 5/2/05

11 12 01 02 03 04 05 06 07 08 09 11 12 01 02 03 04 05 06 07 08 09

Diel Emigration

2003

0

10

20

30 HatcheryNatural

2005

00:00 04:00 08:00 12:00 16:00 20:00 00:000

10

20

30

2004

0

10

20

30

Fish

Cro

ssin

g A

nten

na (%

)

Time

• Smolt production is equivalent between pre- and post-hatchery production years

• Hatchery origin fish emigration rates, timing, and patterns are similar to natural origin fish

Production/Emigration Summary

Physiological & Morphological Sampling

1

23

4 5

8

9

101112

13

17

A. Landmarks

B. Distances-Truss Network

C. Significant discriminant coefficients

Morphological Analysis

Hatchery migrants were longer than natural migrants

Na+, K+ ATPase Activity

Release Block

1 2 3

Na

+, K

+ A

TPas

e(

mol

-P x

g-p

rot

-1 x

h-1

)

0

2

4

6

8

10Hatchery fishNatural fish

Release Block

1 2 3

Release Block

1 2 3

2003 2004 2005

Plasma Na+ & OsmolalityP

lasm

a [N

a+]

(mM

)

125

150

175

200

225

250

Hatchery fishNatural fish

Pla

sma

Osm

olal

ity

(mO

sm)

300

350

400

450

Release Block

1 2 3125

150

175

200

225

250

Release Block

1 2 3

300

350

400

450

2004

2004

20052005

•Hatchery and Natural steelhead of similar genetic parentage differ morphologically and physiologically.

•The observed characteristics provide a baseline measure.

•We will continue to monitor and determine if adult return rates and reproductive success is affected.

Summary

Adult Steelhead Returns

Natural: 36 (20 females/16 males)Hatchery: 38 (13 females/25 males)

Strays: 39 (14 females/25 males)

Relative Fitness

• Determine if the natural and hatchery fish mate randomly and produce offspring with equal survival rates in Abernathy Creek

– Parentage analysis via 11 microsatellite loci• Ground truthed the loci and method

• Estimated error rate (0.8%)

Relative Fitness

– Following our first broodyear (2005)• Genetic diversity among the broodstocks was

maintained among respective progeny

• Females on average produced 4.2 and males 3.4 offspring per spawner

• Natural fish produced 5.83 offspring per spawner

• Hatchery fish produced 1.40 offspring per spawner

• Smolt production is equivalent between pre- and post-hatchery production years

• Hatchery fish emigration rates, timing, and patterns are similar to natural fish

• Hatchery and natural steelhead of similar genetic parentage differ morphologically and physiologically

• Continuing Research– Relate physiology, morphology, and behavior to adult return rates and

reproductive success of succeeding generations– Estimate heritabilities and genetic correlations of fitness-related, life history

traits in relation to return timing, age and size at return (maturity) of succeeding generations

Conclusions