Transport of blue crab larvae by surface currents off Delaware Bay, USA

Abstract

Weekly abundance of larval blue crabs Callinectes sapidus was determined during late summer (1983 and 1984) at 15 stations on the inner continental shelf within 50 km of Delaware Bay, USA. Simultaneous measurements of subtidal, surface flow were made at 5 current meter stations within the study area. During both years, larval abundance was greatest during early August when concentrations in excess of 100 zoeae m super(-3) were commonly observed. By the third week in September, early zoeal stages had disappeared from the water column, and zoeal abundances at all stations were less than 10 zoeae m super(-3). Results of the current meter measurements provide firm evidence of sustained northward flow of surface water on the inner shelf off Delaware Bay during late summer when C. sapidus larvae are common in the plankton.