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