Occurrence of butyltin compounds in freshwater mussels (Elliptio complanata) from contaminated aquatic areas in Ontario, Canada

The antifouling agent tributyltin (TBT) is extremely toxic to some aquatic organisms. The accumulation of butyltin compounds in the tissues of freshwa ter mussels from contaminated areas in Ontario was studied in the field wit h caged mussels (Elliptio complanata). Mussels were placed in four sites fo r 11 months, and one site for 6 months, in locations of previous contaminat ion of water and sediments. Additional cages were exposed for 5 months at t wo of the sites to study the effect of mussel size on accumulation. The mus sels were collected at regular intervals for butyltin analysis. After almos t one year of exposure at four locations, the TBT contents in tissue of mus sels were 9 to 148 ng as Sn/g (wet weight). The results showed that concent rations of TBT in mussels were related to the mussel size and the concentra tions of TBT in contaminated aquatic areas, and that concentrations in muss el tissue increased dramatically over winter. The results of the experiment demonstrated that caged mussels are useful for indicating the presence of TBT in aquatic systems.