Polychlorinated biphenyl accumulation differs among pumpkinseed sunfish during experimental field exposure: the role of invertebrate prey.

The relative importance of aqueous vs. trophic exposure of fish to polychlorinated biphenyls (PCBs) was investigated. The potential role of different invertebrate prey upon PCB accumulation by fish was also investigated. Pumpkinseed sunfish (Lepomis gibbosus) were exposed in the upper Hudson River under conditions that either permitted feeding upon different local prey assemblages, or excluded local prey from fish diets. Total [PCB] was 5x greater in fish exposed to local prey versus those not permitted to feed on local prey. Further, fish with trophic exposure to PCBs exhibited a chlorine shift, a significantly higher proportion of more chlorinated isomers than fish with only aqueous exposure. Total [PCB] differed among benthic invertebrate assemblages. Phytophilous invertebrates had lower [PCB] than benthic invertebrates, and also had lower concentrations of the more chlorinated isomers. Short-term (7-day) exposure of fish did not permit differentiation of PCB accumulation in fish according to differences in diet of native prey assemblages.