EFFECTS OF SEWAGE SLUDGE ON THE BENTHIC INVERTEBRATE COMMUNITY OF THE INSHORE NEW-YORK BIGHT

Benthic invertebrate community structure including species diversity, biomass and trophic structure was examined at a sewage sludge disposal site and nearby 'control' site in the inner New York Bight off New York City. Although both sites are characterized by soft bottoms with high organic carbon, and support similar deposit feeding assemblages, species diversity is lower at the sludge site, reflecting decreased species richness and evenness. Likewise, total biomass as well as the proportional distribution of biomass among trophic groups, differed between sites. A previously suggested indicator species, Capitella capitata, is present in greater numbers at the control station than the sludge station. It is therefore unsuitable as an indicator species of pollution tolerance in the portion of the New York Bight examined in this study. A small polychaete belonging to the family Ampharetidae, Amage auricula, is by far the most abundant animal at the sludge disposal site, but its potential use as an indicator species is complicated by the fact that it exhibits a great tendency for aggregation. Ampeliscid amphipods appear sensitive to the presence of sludge and may be useful as indicators of contamination. Most of the common animals at both stations were aggregated, and it is recommended that future sampling in the area should be by the use of a larger number of small grabs such as the Shipek, rather than a smaller number of large grabs, as this will increase the probability that patchy fauna are encountered. © 1979.