Organotin accumulation in oysters and rock shells under field conditions

This study characterises the accumulation of organotin in oysters (Crassostrea gigas) and rock shells (Thais clavigera and Thais rufotincta) under different field conditions. The bioaccumulation of tributyltin and triphenyltin in oysters and rock shells was less efficient during the winter, when higher levels of tributyltin pollution were not reflected in rock shell concentrations. The accumulations of tributyltin and triphenyltin were higher in T. clavigera than in T. rufotincta, while less difference between the two species was observed during the winter. A negative correlation was found between the ratio of tributyltin/total butyltin and tributyltin content in oysters and rock shells, suggesting that the metabolic rate of tributyltin is burden-dependent in these organisms, and that bioaccumulation factors are reduced by a high tributyltin burden. In addition, persistent accumulation of triphenyltin has a high probability of food chain magnification. These observations provide insights for future study of organotin pollution and suggest considerations for monitoring these species as bioindicators.