Bioaccumulation of DDT in a marine polychaete, the conveyor-belt deposit feeder Heteromastus filiformis (Claparede)

To better understand the fate of toxic pollutants within the sediment column and their uptake by the benthic community, the effects of several sub-lethal DDT concentrations were determined on Heteromastus filiformis (a marine head-down deposit feeder) under laboratory conditions. Net DDT uptake by this polychaete (measured at 5, 11, and 28 days) increased through time for all treatments (2, 4, and 8 μg g−1 DDT in sediments) and reached concentrations of 240, 500, and 870 μg of DDT per g of lipid, respectively, at the end of the experiment. Biota sediment accumulation factor (BSAF) for DDT (organism concentration normalized to lipid content divided by sediment concentration normalized to the sediment total organic carbon content) ranged from 0.4 to 0.8. Sediment reworking rate of H. filiformis measured by fecal pellet production was reduced only when the worms were exposed to the highest concentration (8 μg g−1 DDT after 28 d exposure). Initially, fecal pellets contained 5 to 8 times greater DDT concentrations than the spiked sediments, but these values decreased at 11 and 28 days. In this study, DDT reduced the feeding rate of H. filiformis at a relatively low DDT concentration (8 μg g−1), compared to concentrations reported for marine sediments, after a relatively short time (28 days), and the buried DDT was transported to the sediment-water interface through the fecal pellets.