TBT and intersex in periwinkles
Context of the study
Organotin compounds (like TBT) used in antifouling paints can disrupt the endocrine system of many gastropod species. Concentrations of 1 ng tin / l sea water results in imposex, the development of non functional male reproductive organs in females. In the periwinkle however, higher concentrations of TBT (> 10ng tin/l) can also cause intersex, the transformation of the oviduct into a non functional prostate. Both conditions can lead to female sterility. After TBT was banned in 2003, many periwinkle populations stopped displaying imposex characteristics. It remains unknown whether they still display intersex characteristics.
Content of the study
The study investigated the occurrence of intersex in periwinkles sampled at 5 locations along the Western Scheldt estuary between 2000 and 2002.
Main results of the study
The study showed that in all sampling regions the occurrence of intersex characteristics in periwinkles decreased over the 3 year study period. Intersex characteristics were more observed at former TBT hotspots located near the harbor of Antwerp and Vlissingen. Also the percentage of sterile females decreased in all locations during the study period. These results show the positive effects of the TBT ban.