Diadromous Fish Assemblage Assessment in the Saco River Estuary, ME Kayla Smith James Sulikowski, Ph.D. and Carrie Byron, Ph.D. Dept of Marine Sciences 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 Previous Research 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 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 Introduction Methods Results Conclusions Future Work Diadromous fishes • Provide important links between coastal watersheds and the Atlantic Ocean • Economic and cultural value Introduction Methods Results Conclusions Future Work Diadromous fishes in the Gulf of Maine 12 species Introduction Methods Results Conclusions Future Work Status in the Gulf of Maine • Complicated life history • Severe population declines • Lost connections = impaired ecosystems • Need: better define interactions and linkages between species Introduction Methods Results Conclusions Future Work 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 Channel Gill nets Marsh 4”“Multi and 6”-mesh” mesh 3” 1” ¾” Michigan Sea Grant Introduction Methods Results Conclusions Future Work Upper Middle Multi-mesh • Multi-mesh • 4” mesh Multi-mesh Lower • Multi-mesh • 4” mesh Multi-mesh • Multi-mesh • 6” mesh Gill nets 2012 2013 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. • Temperature • Salinity • Dissolved oxygen Introduction Methods Results Conclusions Future Work Beach Seining 2010-13 Introduction Methods Results Conclusions Future Work Fish Metrics and Abundance Catch-per-unit-effort (CPUE) N = Number of fish caught t = Time of net in water CPUE = N/t/ln/hn ln = Length of net hn = Height of net mesh area Introduction Methods Results Conclusions Future Work Biodiversity Indices Shannon - Wiener Diversity Index 풔 H’ = diversity index, ′ 푯 = − 풑풊 퐥퐧 풑풊 S = total number of species 풊=ퟏ pi = proportion of S represented by the ith species Simpsons diversity index 퐧(풏 − ퟏ) n = total number of individuals of a 푫 = ퟏ − single species 퐍 (푵 − ퟏ) N = total number of individuals caught Introduction Methods Results Conclusions Future Work Preliminary Results – Gill nets • 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 Introduction Methods Results Conclusions Future Work Salinity Gradient 20 A 18 17 16 14 ) ppt 12 10 B B Salinity ( 8 6 6 6 4 2 0 Upper Middle Lower Upriver Mouth Introduction Methods Results Conclusions Future Work Fish Abundance 20 0.006 B 18 0.005 16 14 0.004 ) 12 ppt 10 0.003 B (CPUE) effort unit 8 - Salinity ( Salinity 0.002 per 6 - 4 Catch A 0.001 2 0 0 Upper Middle Lower Introduction Methods Results Conclusions Future Work Fish Abundance 100%100 90%90 80%80 Alosa spp. 70%70 Acipenser spp. 60%60 Morone spp. 50%50 Other 40%40 30%30 20%20 10%10 0 Upper Mid Lower Introduction Methods Results Conclusions Future Work Fish Abundance 100%100 90%90 80%80 Alosa spp. 70%70 57% 57% Acipenser spp. 60%60 87% Morone spp. 50%50 Other 40%40 16% 30%30 43% 20%20 17% 6% 10%10 2% 0 Upper Mid Lower Introduction Methods Results Conclusions Future Work BiodiversitySpecies Richness Indices Shannon Diversity Index Simpson's Index of Diversity Species Richness (n) 2 14 1.81 1.8 12 12 1.6 10 1.4 10 1.23 1.2 1.02 8 1 0.78 6 0.8 0.66 0.6 0.52 3 4 Diversity Indices Diversity 0.4 Richness Species 2 0.2 0 0 Upper Middle Lower Station Introduction Methods Preliminary Results Conclusions Future Work Results – Beach Seining 227 seines 11,544 fish 4% Diadromous Introduction Methods Results Conclusions Future Work Fish Abundance 2010 2011 2012 2013 Introduction Methods Results Conclusions Future Work Life History Groups 100% 11% 90% 80% 70% 61% 33% 60% Freshwater 50% Estuarine 40% Marine 30% 56% 20% 33% Percentage of Catch of Catch Percentage 10% 0% 6% fresh and oligohaline (0-5ppt) mesohaline (5-18ppt) 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 Summary • 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 Introduction Methods Results Conclusions Future Work Summary • 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) Introduction Methods Results Conclusions Future Work Comparison to other estuaries • 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) Introduction Methods Results Conclusions Future Work 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 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 NOAA Section 6 Special License 2013-48-03 Questions? Comments? Suggestions? Introduction Methods Preliminary Results Conclusions Future Work River Herring Counts 88% decline 7,994 Empty Rivers The Decline of River Herring - A Report of the Herring Alliance Source: ASMFC River Herring Compliance Reports. .