The impact of the banning of tributyltin-based antifouling paints on the Sydney rock oyster, Saccostrea commercialis.

Two years after the banning in New South Wales (Australia) of tributyltin (TBT)-based antifouling paints for vessels under 25 metres in length, the impact on the Sydney rock oyster, Saccostrea commercialis, has been assessed. Reduced growth and shell deformities present before banning were found to be absent and healthy oysters contained TBT at concentrations close to the detection limit of 0.2 micrograms Sn kg-1. High tissue concentrations of both copper and zinc, prior to banning were also significantly reduced. This behaviour was predicted by field experiments which showed that TBT had a synergistic effect on the uptake of copper. The distribution of both TBT and copper in the various organs of the oyster were examined in an attempt to explain this synergism.