Distribution of butyltins (TBT, DBT, MBT) in sediments of Gulf of Cádiz (Spain) and its bioaccumulation in the clam Ruditapes philippinarum.

Surface sediment samples were analyzed for organotins namely tributyltin (TBT), dibutyltin and monobutyltin from six areas located in the Gulf of Cádiz (14 stations), Spain. The total butyltin ranged between undetected and 1,580 ng Sn g(-1). TBT generally prevailed in most of the samples, suggesting fresh inputs of butyltin compounds and/or less degradation of TBT. The observed levels of butyltins at several sites are much higher than that required to induce toxic effect on marine organisms, suggesting that these sediments are polluted with butyltin compounds. The clam Ruditapes philippinarum was used for studying bioaccumulation of butyltins by exposing them to contaminated sediments from the Gulf of Cádiz over a period of 28 days under laboratory conditions. Biota-sediment accumulation factor (BSAF) ranged from 0.44 to 3.99.