Transport of dungeness crab (Cancer magister) megalopae into Glacier Bay, Alaska

Abstract

Areas of high Cancer magister larval recruitment and transport mechanisms were identified in the lower portion of Glacier Bay, Alaska. Megalopae were collected at three sites in 2004 and 2005 using light traps positioned within 1 m of the surface and bottom at 10 m depth. Surface traps captured 96.5 - 99.4 % of megalopae collected. Megalopae abundances were highly pulsed and decreased with increasing distance from the mouth of Glacier Bay. Spatial variation was similar between years with significant differences among all sites in 2005. Half of the total annual megalopae supply occurred over just two nights in September or October, the dates of which varied by location. Megalopae abundance in Bartlett Cove was negatively cross-correlated with tidal amplitude at -3 to + 1 d lags and positively cross-correlated with maximum wind speed at a 0 d lag. Megalopae abundance in the South Beardslee Islands was positively correlated with tidal amplitude and negatively correlated with maximum wind speed at +2 to +3 d lags. Abundance in the North Beardslee Islands was low and not correlated with tides or winds. Spatial variation in megalopae abundance and correlations between abundances and transport processes suggests that Dungeness crab megalopae are transported into Glacier Bay.