PREDATOR-PREY RELATIONSHIPS OF WINTER FLOUNDER, PLEURONECTES-AMERICANUS, IN THE NEW-YORK BIGHT APEX

A 39-month study of the effects of cessation of sewage sludge disposal in the New York Bight apex on the diets of certain fishes and on the benthic macrofaunal community provided an opportunity to examine preda tor-prey relationships of winter flounder, pleuronectes americanus, on e of the common predators in the area. Benthic macrofauna and winter f lounder were collected monthly and bimonthly, respectively, from July 1986 through SePtember 1989 at three sites in the Bight apex that are variably influenced by sewage sludge. There were limited changes in wi nter flounder diets and abundance of dominant benthic macrofaunal spec ies following cessation of sewage sludge disposal. The comparison of v olumetric contribution of common prey in flounder stomachs to potentia l-prey abundance in benthic samples suggested several relationships- T hese included evidence of preferential predation on the polychaete Phe rusa affinis; this selective preference may be associated with its hig h caloric content as well as with its average high biomass density. ot her common prey, primarily polychaetes but including an anthozoan, wer e also preyed upon in proportions greater than their abundance in the environment. Some moderately abundant potential prey, such as the smal l near-surface-dwelling mollusc Nucula proxima and the ribbon worm Cer ebratulus lacteus were not commonly preyed upon suggesting they were u navailable as prey or were avoided by winter flounder. Corresponding f luctuations in abundances and predation of the pollution-tolerant poly chaete Capitella sp. and the pollution-sensitive amphipod Unciola irro rata suggested a proportional consumption relationship in association with sludge disposal and its cessation.