Accumulation, Metabolism, and Depuration of Organotin Compounds in the Marine Mussels Mytilus graynus and Mytilus edulis under Natural Conditions

The accumulation, transformation, and depuration of tri-n-butyltin (TBT) were studied over periods of approximately 60-70 days using marine mussels, Mytilus graynus and Mytilus edulis, under natural conditions. M. graynus collected at a lightly polluted site were transplanted to a highly polluted site and M. edulis collected at a highly polluted site were transplanted to a lightly polluted site. TBT taken up in M. graynus showed a bioconcentration factor of 10 500 in the accumulation phase. Di-n-butyl(3-oxobutyl)tin, which is a main metabolite of TBT in M. edulis, showed a longer half-life (8.13 days) than that of the parent compound (4.82 days) in the depuration phase. On the other hand, another metabolite, di-n-butyl(3-hydroxybutyl)tin, showed a shorter half-life (3.98 days) than that of the parent compound. The different half-lives among TBT and its metabolites are responsible for the different metabolic patterns in blue mussels at each sampling time.