The relationship between lipid composition and seasonal differences in the distribution of PCBs in Mytilus edulis L.

Abstract

The concentrations of individual chlorobiphenyl congeners were measured in the mussel Mytilus edulis transplanted to several stations in Buzzards Bay and Nantucket Sound, MA (USA). Individual stations represented a gradient of chemical contamination and the sampling period extended over a complete annual cycle. Fluctuations in concentrations of some chlorobiphenyl congeners were apparent at all stations during the late spring and early summer with a marked decline occurring during autumn; this pattern was correlated with the seasonal cycle of gametogenesis and spawning activity. Relative redistribution and release of individual chlorobiphenyl congeners associated with spawning is not consistent, suggesting differential partitioning of specific congeners in different tissues or lipid pools. These patterns are consistent with our general view of the bioconcentration of organic contaminants in marine organisms. The major factors controlling the distribution of PCBs in mussels appear to be the relative concentrations of individual contaminants in ambient waters, modified to some extent by differences in partitioning between organisms and water (as indicated by differences in K ow), and seasonal variations in lipid content.