Worldwide Occurrence of Organotins from Antifouling Paints and Effects in the Aquatic Environment

Abstract

Organotins belong to the most toxic pollutants for aquatic life known so far. Widespread contamination of harbors and areas with high shipping activities occurs globally due to the ongoing use of tributyltin (TBT) in antifouling paints on large vessels. In the last decade, organotin pollution has spread to developing countries. Contamination decreased only slowly several years after regulation of antifouling paints in small vessels and remains widespread in sediments and marine biota. TBT degradation in sediment is very slow under anaerobic conditions and remobilization occurs via mixing and dredging. Ecotoxicological effects occur globally in marine gastropods, which are affected by masculinization (imposex) at ng L−1 levels leading to population declines. Present TBT levels in harbors and adjacent areas are still in the range of effect levels. Recently, also androgenic activity of TBT in fish was reported. A large variety of organisms, in particular early life stages, are susceptible to low TBT concentrations of a few 100 ng L−1. Bioaccumulation leads to significant residues in aquatic biota including marine mammals. Despite regulations, ecotoxicologically relevant contamination of marine ecosystems is persisting, particularly in sediments. The recent spread into developing countries indicates that organotin contamination has ongoing ecotoxicological relevance globally.