Aroclor 1268 and toxaphene in fish from a southeastern US Estuary

PCBs and toxaphene were analyzed in fish and their prey from an industrialized estuary in southeastern Georgia (USA). PCB concentrations were highest in forage fish (170 mu g/g lipid) and were 1-3 orders of magnitude higher in biota from a heavily contaminated salt marsh in the upper estuary as compared with levels in similar species from two reference sites. Tissue PCB profiles matched that of Aroclor 1268, a highly chlorinated formulation used exclusively at a Superfund site in the upper estuary. Tissue profiles of fish gut contents and of species representing a simple food chain indicated that PCBs are likely transferred via the food web. Components of toxaphene, which was discharged from a facility in the lower estuary, were detected and confirmed in fatty organs of fish using gas chromatography with electron capture and mass spectrometric detection. Estimated toxaphene concentrations were 0.5-1 mu g/g lipid. These results suggest that PCBs and toxaphene from point sources in different parts of the estuary are transferred locally through the food web and that fish transport these contaminants out of the heavily contaminated salt marshes during their semiannual movements within the estuary.