DEMERSAL ZOOPLANKTON AT STELLWAGEN BANK, MASSACHUSETTS BAY: TEST OF A NEW REENTRY TRAP

A new reentry trap is described for sampling demersal zooplankton that can be deployed and retrieved from the surface. The trap was field tested at Stellwagen Bank, Massachuestts, site of previous studies of demersal zooplankton that used diver-placed reentry traps. The new traps captured an assemblage of demersal animals taxonomically similar to those captured in earlier reentry trap studies. Dominant taxa included nematodes, harpacticoid copepods, and, at one station, ostracods. Large-bodied taxa such as amphipods and shrimps were rare. Abundances of demersal zooplankton were low at three of the four sites sampled, and similar to previous reports, suggesting that some factor, perhaps disturbance or predation, limits demersal zooplankton abundance in this productive ecosystem.