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

Abstract

Weekly abundance of larval blue crabs CaUinectes sapidus was determined during late summer (1983 and 1984) at 15 stahons 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-3 were commonly observed. By the thud week in September, early zoeal stages had &sappeared from the water column, and zoeal abundances at all stations were less than 10 zoeae 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. This northward flow occurs on time scales relevant to the rate of larval development of C. sapidus and may b e important in retaining zoeae near the parent estuary.

Movements of Marine Fish and Decapod Crustaceans: Process, Theory and Application

“…For example, Epifanio et al (1989) sampled the spatial distribution of crab zoea at weekly intervals and found that this was insufficient to resolve the details of zoeal transport. Subsequent analyses of wind vector and surface current patterns indicated that the distance a parcel of surface water would have travelled during any week was greater than the radius of the study area.…”

Advection-diffusion-mortality solutions for investigating pelagic larval dispersal

“…Recruitment to the juvenile phase, however, requires that later larval stages return to the vicinity of an estuary. Blue crab Callinectes sapidus, discussed by Epifanio et al (1989) and Goodrich et al (1989), is a good example of such a n organism.…”

Pelagic dispersal of Norway lobster Nephrops norvegicus larvae examined using an advection-diffusion-mortality model

“…Blue crab postlarvae return to an estuarine environment in order to settle into nursery areas. Epifanio et al (1989) have argued that although blue crab larvae are transported southward away from the mouth of the Delaware estuary by a narrow buoyancydriven coastal current, larvae that are dispersed offshore may be carried northward again by the mean wnd-driven flow on the inner continental shelf thus enabling them to be retained in the vicinity of the estuary. Likewise Goodrich et al (1989) have argued that wind-driven surface flows, particularly those related to storm events, are important for transporting blue crab megalopae from the open continental shelf into Chesapeake Bay prior to settlement.…”