| Abstract: | Blue crab larvae are advected out of Middle Atlantic Bight estuaries immediately after spawning occurs in the estuary entrance. For the next 30 to 50 days the larvae are found offshore and mainly at the surface where they are influenced by wind-driven currents. Using a previously derived circulation model and winds from Norfolk (VA) airport, a backward trace is made from where relatively dense concentrations of megalopae were found in the Chesapeake Bight during 1983 to a point of origin (spawning).During 1983, the megalopae encountered on the shelf had their origin in Chesapeake Bay and took, at minimum, 31 to 36 days to grow to the megalopae stage. Wind forcing dominated the inner shelf region in the summer of 1983 and the resulting dispersion of Chesapeake Bay megalopae occurred briefly in the southern sector early in the season, but toward the northern sector over most of the season. Although no firm conclusions could be drawn regarding the mechanism for return, it did not seem likely that wind advection back to the point of origin would be effective. |
