BIOACCUMULATION OF TETRACHLOROBIPHENYL AND HEXACHLOROBIPHENYL CONGENERS BY YOLDIA-LIMATULA AND NEPHTYS-INCISA FROM BEDDED SEDIMENTS - EFFECTS OF SEDIMENT-RELATED AND ANIMAL-RELATED PARAMETERS

Sediments from Narragansett Bay (RI, USA) were fortified with two chlo robiphenyl congeners, 2,4,2',4'-tetrachlorobiphenyl (IUPAC 47) and 2,4 ,5,2',4',5'-hexachlorobiphenyl (IUPAC 153), and equilibrated for vario us times up to 30 d to assess the bioaccumulation potential of sedimen t-sorbed polychlorinated biphenyls by the benthic invertebrates Yoldia limatula and Nephtys incisa. Bioaccumulation was investigated at stea dy state and using a single-compartment kinetic model over exposure pe riods of up to 60 d for Nephtys and 30 d for Yoldia. Normalization of exposure and tissue accumulation data to hydrophobic reservoirs yielde d accumulation factors (AFs) that fell within model prediction ranges. However, persistent, statistically different values of AFs were obtai ned from sediments with varying organic carbon contents. Growth of the organisms, feeding strategies, and lipid content were all significant variables in interpreting wet weight steady-state accumulation. Kinet ically determined AF values were not statistically different from thos e measured at steady state. A role of interstitial water colloidal org anic matter in mediating bioaccumulation was strongly suggested by the results.