695 
Thus, elevated concentrations of most contaminants in the 
Bight and its biota, excepting PCBs, and human pathogens, are 
primarily due to sources other than sewage sludge. However, up to 
half of the elevated PCB concentrations in biota of the Bight 
(0.1-0.5 g/g, wet weight) may be derived from sewage sludge 
(O'Connor et al., in press c). The PCBs in sewage sludge are 
biologically more available than those in dredged materials. While 
PCBs are ubiquitous in the living marine resources of the region, 
concentrations in organisms seaward of the Hudson-Raritan Estuary 
are low compared to concentrations in fishes and invertebrates of 
the Estuary. Based upon existing data, organisms collected in 
Bight waters and commonly found in the human diet contain low 
levels of PCBs and present no health hazard to the average person. 
However, PCB concentrations in the waters and sediments of the 
Bight are high enough to be suspected of causing ecological damage. 
Bottom sediment samples recently analyzed for trace metals 
(Cr, Cu, Ni, Pb, and Zn) have shown that the distributional pattern 
of sediment metals in the New York Bight apex has not changed 
significantly over the past five years (NOAA, 1981). The volume of 
sludge ocean dumped has increased over one third in the same time 
period. 
Biological Effects: 
Sewage sludge plays a major role in degrading the benthos of a 
small area just west of the sewage sludge dumpsite, and contributes 
to the altered benthic communities observed over about 240 km? 
(90 mi’). The principal impact over the larger area is one of 
organic enrichment and pathogen concentration by shellfish. However, 
some species (e.g. Ampelisca, Unicola irrorata, and Erichthonus 
rubricornis) have been almost entirely eliminated from the region, 
presumably as a result of toxic effects of sewage sludge combined 
with those of other contaminants (Boesch, in press). 
