ENHANCED ACCUMULATION OF PCB CONGENERS BY BALTIC SEA BLUE MUSSELS, MYTILUS-EDULIS, WITH INCREASED ALGAE ENRICHMENT

The objective of this study was to examine if natural variations in th e quantity of phytoplankton-derived particulate and dissolved organic carbon influences the accumulation of polychlorinated biphenyls (PCBs) in the tissues of Baltic Sea blue mussels (Mytilus edulis L.). In a l aboratory flow-through experiment we exposed M. edulis to the technica l PCB mixture Aroclor(R) 1248 for 21 d at three different enrichments of the unicellular green algae Chlamydomonas sp., 0.10, 0.16, and 0.32 mg particulate organic carbon (POC)/L. Tissue and water concentration s were determined for seven PCB congeners (International Union of Pure and Applied Chemistry [IUPAC] 52, 101, 105, 118, 138, 153, and 180), and 21-d bioaccumulation factors were calculated against total water c oncentrations. Contrary to what would be expected, an increase in alga e enrichment from 0.10 to 0.32 mg POC/L resulted in an enhanced PCB ac cumulation by a factor of approx. 2. This increase in PCB accumulation was more pronounced for PCB congeners with lower hydrophobicity. Thes e observations have implications for the design of laboratory accumula tion studies and potentially for PCB accumulation and cycling in field populations of suspension-feeding mussels in response to changes in e utrophication status.