Butyltin accumulation in two marine bivalves along a pollution gradient

In the present study, we describe a field survey regarding the effect of ambient water conditions in the accumulation of tributyltin (TBT) and its metabolites in green mussels (Perna viridis) and Pacific oysters (Crassostrea gigas). The results showed that following the changes in TBT pollution levels, the accumulation of butyltins exhibited clear differences between oysters and mussels. The ratio of TBT to total butyltin (TBT:SigmaBT) decreased from 0.87 to 0.31 with increasing TBT burdens in the oysters. This status suggests that following the increases of TBT burdens, the metabolic rates of TBT were clearly enhanced in oysters; however, this phenomenon was not shown in mussels. The TBT:SigmaBT remained relatively constant at approximately 0.7 in the mussels despite the TBT burdens. Because of this phenomenon, the opposite status of different TBT burdens between oysters and mussels were present at different TBT pollution levels. These observations may provide valuable insight when evaluating or comparing TBT pollution in the environment using oysters and/or mussels as bioindicators.