Presentation on theme: "Environmental Effects on Recruitment of Northern Shrimp in the Gulf of Maine Anne Richards Michael Fogarty David Mountain NOAA National Marine Fisheries."— Presentation transcript:
Environmental Effects on Recruitment of Northern Shrimp in the Gulf of Maine Anne Richards Michael Fogarty David Mountain NOAA National Marine Fisheries Service Woods Hole, MA
stock-recruit-environment relations mechanisms for recruit-env’t relation Outline
Northern Shrimp Pandalus borealis Boreal distribution Gulf of Maine=southern limit Locally important fishery from Shumway et al. 1985 Life history Fishery
Impetus Conventional wisdom: temperature = primary regulating factor will “…not respond well to attempts to control exploitation” (Apollonio et al. 1986)
Conclusion Shrimp recruitment dependent on SSB and spring temperatures (surface and bottom)
Mechanisms: Spring SST Spring surface temperature effect (larvae): –Appears intuitively correct –But counters laboratory studies: better growth and survival at warmer temperatures. –Indirect effect, e.g. match-mismatch?
Match-Mismatch Hypothesis Coastal Gulf of Maine: Bloom timing determined by solar insolation (Townsend and coauthors) Shrimp development: temperature- dependent