Relationship between PCB concentrations and reproduction in mussels mytilus edulis

Changes in the concentrations of PCBs and fats were followed in mussels Mytilus edulis, transferred vice versa between a polluted estuary (Westerschelde) and a relatively low-pollution sea-arm (Oosterschelde). The concentrations in the mantle, which contains the gonads, were determined separately from the rest of the body. The fat content of the mantle increased 1 1 2 - to 2-fold during the observation period (autumn, winter) and remained constant in the rest of the body. Polychlorinated biphenyls (PCBs) in mussels transferred from the polluted to the less polluted area were not eliminated. In the mussels transferred to the polluted area the increase of the PCB content was 2- to 3-fold over a period of 3 months. PCBs in the mantle, and therefore in the gonads, can amount to more than 40% of the total PCB load in a mussel. It was concluded that during the spawning of gametes a substantial proportion of the PCBs may be shed.