Kayla Smith James Sulikowski, Ph.D. and Carrie Byron, Ph.D.

Dept of Marine Sciences

Diadromous Fish Assemblage Assessment in the Saco River Estuary, ME

Saco River Estuary

• Nursery ground

• Foraging stop-over site for migratory fishes

• 60 marine, diadromous and freshwater species observed since 2007 (J. A. Sulikowski, unpubl. data)

Introduction Methods Results Conclusions Future Work

o Reynolds and Casterlin, 1985, Hydrobiologia

– n = 18

o Furey and Sulikowski, 2011, Northeastern Naturalist

– n = 24

o Little et al. 2013, Journal of Applied Ichthyology

Previous Research

Introduction Methods Results Conclusions Future Work

Gear types used include: Hook and line Plankton tows Light and modified lobster traps Beam and otter trawl Seine, D-frame and gill netting Settlement collectors Long line

• Provide important links between coastal watersheds and the Atlantic Ocean

• Economic and cultural value

Introduction Methods Results Conclusions Future Work

Diadromous fishes

Diadromous fishes in the Gulf of Maine

12 species

Introduction Methods Results Conclusions Future Work

Status in the Gulf of Maine

Introduction Methods Results Conclusions Future Work

• Complicated life history

• Severe population declines

• Lost connections = impaired ecosystems

• Need: better define interactions and linkages between species

Does fish species diversity, richness and abundance vary

along a river gradient in the Saco River estuary?

Is there interannual variability in the fish community?

Introduction Methods Results Conclusions Future Work

River Channel Sampling

10

8

6

4

2

Introduction Methods Results Conclusions Future Work

3” 1” ¾”

Channel Marsh

Michigan Sea Grant

Gill nets “Multi-mesh” 4” and 6” mesh

Introduction Methods Results Conclusions Future Work

Upper

Middle

Lower

Gill nets 2012 2013

Multi-mesh

Multi-mesh

Multi-mesh

• Multi-mesh • 4” mesh

• Multi-mesh • 4” mesh

• Multi-mesh • 6” mesh

Introduction Methods Results Conclusions Future Work

Sampling Methods – Gill nets • Set between 2 and 4 a.m.

• Pick-up between 6 and 8 a.m.

Introduction Methods Results Conclusions Future Work

• Temperature • Salinity • Dissolved oxygen

Introduction Methods Results Conclusions Future Work

Beach Seining 2010-13

CPUE = N/t/ln/hn

N = Number of fish caught t = Time of net in water ln = Length of net hn = Height of net mesh area

Catch-per-unit-effort (CPUE)

Fish Metrics and Abundance

Introduction Methods Results Conclusions Future Work

𝑫 = 𝟏 − 𝐧(𝒏 − 𝟏)

𝐍 (𝑵 − 𝟏)

𝑯′ = − 𝒑𝒊

𝒔

𝒊=𝟏

𝐥𝐧 𝒑𝒊

n = total number of individuals of a single species N = total number of individuals caught

H’ = diversity index, S = total number of species pi = proportion of S represented by the ith species

Simpsons diversity index

Shannon - Wiener Diversity Index

Biodiversity Indices

Introduction Methods Results Conclusions Future Work

• 17 trips June through September

– 2012 (5)

– 2013 (12)

• 230 hours fished

– Average soak of 3.7 hours

• 353 fish caught

– 13 species, juveniles and adults

– 89 % diadromous fish

Preliminary Results – Gill nets

Introduction Methods Results Conclusions Future Work

Salinity Gradient

6 6

17

0

2

4

6

8

10

12

14

16

18

20

Upper Middle Lower

Salin

ity

(pp

t)

B B

A

Upriver Mouth Introduction Methods Results Conclusions Future Work

Fish Abundance

Introduction Methods Results Conclusions Future Work

0

0.001

0.002

0.003

0.004

0.005

0.006

0

2

4

6

8

10

12

14

16

18

20

Upper Middle Lower

Cat

ch-p

er-

un

it e

ffo

rt (

CP

UE)

Salin

ity

(pp

t)

B

B

A

0

10

20

30

40

50

60

70

80

90

100

Upper Mid Lower

Alosa spp.

Acipenser spp.

Morone spp.

Other

Fish Abundance

Introduction Methods Results Conclusions Future Work

100%

90%

80%

70%

60%

50%

40%

30%

20%

10%

2%

17% 6%

16%

43%

87%

57% 57%

0

10

20

30

40

50

60

70

80

90

100

Upper Mid Lower

Alosa spp.

Acipenser spp.

Morone spp.

Other

100%

90%

80%

70%

60%

50%

40%

30%

20%

10%

Fish Abundance

Introduction Methods Results Conclusions Future Work

0

2

4

6

8

10

12

14

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2

Upper Middle Lower

Station

Spe

cie

s R

ich

ne

ss

Div

ers

ity

Ind

ice

s

Shannon Diversity Index Simpson's Index of Diversity Species Richness (n)

12

10

3

1.23

1.81

1.02

0.52

0.78 0.66

Species Richness Biodiversity Indices

Introduction Methods Preliminary Results Conclusions Future Work

Results – Beach Seining

227 seines 11,544 fish 4% Diadromous

Introduction Methods Results Conclusions Future Work

2013 2012

2011 2010

Fish Abundance

Introduction Methods Results Conclusions Future Work

Life History Groups

Water classifications from the EPA’s Volunteer Estuary Modeling Manual. Fish species life history classifications categorized by Dionne et al. (1999) and FishBase v. 04/2014.

Introduction Methods Results Conclusions Future Work

6%

56% 33%

33% 61%

11%

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

fresh and oligohaline (0-5ppt) mesohaline (5-18ppt)

Pe

rce

nta

ge o

f C

atch

Freshwater

Estuarine

Marine

• 33 fishes and 4 crustacean species – Gill nets (13), Beach seines (28)

• 5 federally-listed species – Endangered (shortnose sturgeon)

– Threatened (Atlantic sturgeon)

– Species of Concern (blueback herring, alewife, and rainbow smelt)

• 4 species of recreational importance – largemouth and striped bass, pumpkinseed, bluefish

• 3 species with commercial fisheries – Atlantic herring, winter flounder, red hake

Summary

Introduction Methods Results Conclusions Future Work

• Fish abundance, richness and diversity

– Lowest in areas with significant salinity mixing

– Greatest in areas with less tidal influence

• Diadromous fish not observed

– brook trout, sea lamprey and Atlantic salmon*

• Comparison to Wells Reserve sampling and Penobscot River (Kiraly et al.,2014)

Summary

Introduction Methods Results Conclusions Future Work

• Since 2007, (60) species have been observed in the SRE and Bay – Little River (33) – Kennebec Point (27) – York River (24) – Wells Harbor (24) – Weskeag River (10) – Penobscot River (35) – Penobscot Bay (22) – Casco Bay (25) – Muscongus Bay (24)

(Orrniger et al. 2005; Lazzari et al. 1996; Dionne et al. 2006; Ayvazian et al. 1992; Kiraly et al 2014 Lazzari 2002; Lazzari and Tupper 2002; Lazzari et al. 2003)

Comparison to other estuaries

Introduction Methods Results Conclusions Future Work

• Continue to collect abundance data

– Correlation with freshwater discharge and time from peak high tide

• Create a static food web model

– Mass-balance approach

– Goal: Determine role of diadromous fish as predators and prey

Future Work

Introduction Methods Results Conclusions Future Work

Thank you! • Sulikowski Lab – Brenda Rudnicky, Julia Reynolds, Ashleigh Novak • This research was conducted as part of the Sustainability Solutions Initiative,

supported by National Science Foundation award EPS-0904155 to Maine EPSCoR at the University of Maine

Introduction Methods Preliminary Results Conclusions Future Work

Questions? Comments? Suggestions?

NOAA Section 6 Special License 2013-48-03

River Herring Counts

Empty Rivers The Decline of River Herring - A Report of the Herring Alliance Source: ASMFC River Herring Compliance Reports.

7,994

88% decline