Bioaccumulation and elimination of chlordane by selected intertidal benthic fauna

Bioaccumulation and elimination of nine principal components of technical chlordane applied to a previously uncontaminated intertidal sand flat were observed in adults of the bivalve species Chione stutchburyi and Tellina liliana, the gastropod Amphibola crenata, and polychaetes (Glycera americana, Nicon aestuarinensis, and Platynereis australis). The patterns of accumulation differed markedly between species, depending on whether the organisms acquired chlordane predominantly from the sediment phase or from both sediment and water phases. The surface-dwelling (Amphibola crenata) or surface-feeding (Tellina liliana) species attained chlordane levels up to three times that of the suspension feeder, Chione stutchburyi, a short time after application. The lipid-normalized bioconcentration curves for both shellfish species declined to similar steady-state values, which suggested that simple equilibrium partitioning between organism lipid and sediment organic carbon phases regulates long-term bioconcentration. The composition of the adsorbed chlordane, although very similar to that of the technical product applied to the sand flat, also showed some species dependence with a preference for the more chlorinated components of chlordane to accumulate in the sediment-feeding species. No traces of the metabolites oxychlordane and heptachlor epoxide were found in any of the species tested over the 100-d duration of the study.