Influence of diet on the bioaccumulation of PCBs.

The levels of several chlorinated biphenyls (PCBs) congeners were analysed in muscle of flounder (Platichthys flesus), which were kept in semi-field condition for 1 month. The influence of resuspended sediments and two diets (worms and shrimps) on PCB accumulation in these fish was tested. Highest concentrations were among PCB 138 and 153 in both abiotic (sediment and suspended particulate matter (SPM)) and biotic compartments (shrimps, worms and flounder). Whereas all PCB congeners vary in concentration between polluted and non-polluted sediment, SPM and mussels, only high chlorinated congeners (101, 105, 153, 180 and 187) are significantly different between the worms and shrimps. Differences in bioaccumulation of PCBs by fish induced by differences in food composition were not found. For the low chlorinated compounds, however, pollution exposure might account for the higher concentration found in exposed fish.