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Can we have our herring and eat our salmon, too? A qualitative approach to modeling trade-offs in Puget Sound . Tessa Francis Puget Sound Institute, University of Washington Tacoma Chris Harvey Northwest Fisheries Science Center, NOAA, Seattle, WA Mike Carey USGS, Anchorage, Alaska, USA.
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Can we have our herring and eat our salmon, too?A qualitative approach to modeling trade-offs in Puget Sound Tessa Francis Puget Sound Institute, University of Washington Tacoma Chris HarveyNorthwest Fisheries Science Center, NOAA, Seattle, WA Mike CareyUSGS, Anchorage, Alaska, USA
Understanding tradeoffs Rodger Jackman/ gettyimages.com
Management submodel Assessment and policy decisions Fisheries submodel Community submodel Habitat EcoPath with EcoSim Harvey et al. 2012 Estuaries and Coasts The Atlantis Ecosystem Modeling Framework Isaac Kaplan, Chris Harvey, Phil Levin, Jason Link, Howard Townsend NOAA NMFS Beth Fulton CSIRO Australia Biogeochemistry Hydrographic submodel Climate and oceanography Slide courtesy of Isaac Kaplan
Qualitative Modeling (+) (+) (-) (-) (-) (+) Community Matrix
Qualitative ModelingPredictions and Reliability Predicted Response(pos, neg, neutral) Community Matrix Reliability ΣLinks between pairs Total links in web adj(-A) perm(minor(abs(A))) Σ Links between pairs adj(-A) A Dambacher et al. 2003, 2007
Qualitative ModelingStep 1: Simplify Harvey et al. 2012 Estuaries and Coasts
Diet > 0.1 Predation > 0.1 Pinnipeds Salmon Herring Forage fish Juv. salmon Juv. herring Macro- Zooplankton Copepods Phytoplankton
Scenario: increase herring Pinnipeds ? Salmon Herring ? Forage fish Juv. salmon Juv herring Macro- Zooplankton Copepods Phytoplankton
Scenario: decrease pinnipeds Pinnipeds ? Salmon Herring ? Forage fish Juv. salmon Juv. herring Macro- Zooplankton Copepods Phytoplankton
Tradeoffs between recovery targets Winners Losers Scenario Tradeoff - No Forage fish Phyto Adult salmon Adult salmon Herring Pinnipeds Pinnipeds Juv. salmon Pinnipeds - No Yes Herring Juv. herring Juv. herring Yes Herring Phyto Copepods Copepods Zooplankton Zooplankton
EcoSim scenario: Increase eelgrass by 100% Plummer ML et al. 2012 Ecosystems
Compare to Ecosystem Model Pinnipeds Salmon Herring Forage fish Juv. salmon Juv. herring Macro- Zooplankton Copepods Eelgrass Phytoplankton
Bottom Line • Qualitative models can be used to identify tradeoffs in EBM. • Qualitative models can corroborate results from fancy ecosystem models. • These models are useful in data-poor systems, and to help guide recovery strategies.
Opportunities • Suggest implications of recovery actions • Spatially-explicit food web scenarios • Lingcod • Crabs • Birds • Explore hypotheses about food-web interactions, management actions… easily • Compare with/groundtruth complex ecosystem models Rodger Jackman/ gettyimages.com
Strong Diet Overlap during Critical Growth Period Between juvenile Salmon spp. and Herring Euphausiid Chum Salmon show Least overlap with Other salmon & herring
Simulated Predation Demand by Resident Chinook in Puget Sound FL > 300 mm -Herring are the predominant prey of Chinook >300 mm throughout the year -Over 1,500 metric tons of herring consumed by resident Chinook annually in PS
Size-selective predation on Herring by Juvenile & Resident Chinook Salmon Herring found in age-0 Chinook stomachs are significantly smaller than those sampled Concurrently with MW Trawl Same for larger resident Chinook
Conclusions • Tradeoffs between salmon and herring exist under some circumstances • Via competition for macrozooplankton • Dependent on abundance of salmon • Qualitative modeling can highlight specific key interactions/biological parameters that may determine tradeoffs • Zooplankton abundance • Top-down pressure by juvenile salmon
Compare qualitative model with ecosystem model California Current groundfish: key prey species Pinnipeds Diving seabirds Surface seabirds Chinook mackerel Bocaccio Ecosystem Model(Atlantis) Qualitative Model Juvenile ShallowRockfish Shallow Small Rockfish Juv Bocaccio Krill Forage Fish Other rockfish Hake Myctophids Benthic grazers Krill Forage Fish Other rockfish Euphausiids Deposit feeders Benthic Grazers copepods Micro zooplankton Large phyto Small phyto