Contamination by organotin(tributyltin and triphenyltin) compounds from antifouling paints and endocrine disruption in marine gastropods

The third countrywide survey on imposex and organotin contamination in the rock shell was conducted in 93 locations along the Japan coast between September 1996 and January 1999. The percentage occurrence of imposex was still high in 86 locations whereas no or rare instances of imposex were found in the remaining seven locations. Severe imposex symptoms were observed in the rock shell populations from 40 locations. Temporal decreases in the tissue concentrations of tributyltin (TBT) were not very distinct although those of triphenyltin (TPT) were clearly observed in almost all surveyed locations. Decreased catches of the ivory shell were thought to be caused mainly by the dysfunction of ovaries due to suppressed ovarian maturity including spermatogenesis, accompanied by imposex possibly induced by TBT and/or TPT from antifouling paints. Endocrine disruption resulting in the masculinization of females was also observed in abalone, possibly caused by organotins, such as TBT and TPT.