Estuarine production of juvenile dungeness crab ( cancer magister) and contribution to the Oregon-Washington coastal fishery

摘要: Estuaries provide nursery habitat for juvenile stages of several commercial decapod crustaceans worldwide, and those in the Northeastern Pacific are viewed as providing this function Dungeness crab,Cancer magister. It is difficult to ascertain degree which such estuarine production juveniles eventually contributes coastal adult populations fisheries since there no direct surveys abundance. As other authors have done, we used fishery landings data compute long-term average contribution 1 + crab reared estuaries future fisheries. We focused on Oregon Washington states, but grouped two large geographic zones by combining ports adjacent Large Estuarine Zones (LEZ; Grays Harbor Willapa Bay, Washington, both sides Columbia River) Small (SEZ; all Oregon). Mortality estimates were reduce abundance surviving legal males, portrayed percent Trends SEZ indicate that an only about 5–7% adds population $0.7 million fishery. The 25–30% LEZ (but may be higher interannual density varies up 5 times) worth $3.9 based present ex-vessel value. Analyses distribution majority (50–80%) located lower side channels (LSC) spring summer where temperature prey within intertidal flats high. potential dollar value equivalent male produced from $180 ha−1 LSC $280 highest), habitats ($50–100 ha−1). provides a relatively stable source recruits populations, systems important nurseries. Since settlement larvae does occur highly variable, especially when physical forcing or unusual events lead low survival 0+ cohort. An unusually long period very 1981–1987 interpreted light Mount St. Helens eruption (1980) subsequent transport deposition fine silt fractions over much nearshore shelf adversely affected year classes small, early benthic phase at time.