Unregulated use of TBT-based antifouling paints in Israel (eastern Mediterranean):high contamination and imposex levels in two species of marine gastropods

Abstract

The use of tributyltin (TBT)-based antifouling paints is unregulated in Israel, and levels of contamination are high along the Mediterranean coastline there. This is indicated by concentrations of butyltins found in the tissue, and by imposex in the whelks Stramonita haemastoma and Hexaplex trunculus. Both the old (since 1974) and new (since late 1995) marinas we studied are hotspots of pollution. Imposex indices were very high at the old marina (RPSI > 100, VDSI 4 to 5); all female H. trunculus and some S. haemastoma were sterile within a distance of ca 1 km from it. The new marina offered a unique opportunity to witness the rapid and intense response of the whelks to TBT pollution in an open coastline. Despite a marked decrease in levels of contamination at distances of 1 to 2 km from both marinas, there were nevertheless detectable levels of butyltins sufficient to cause imposex in reference sites far from high shipping activity. There is evidence that TBT contamination affects abundance and relative growth rates, of male and female, of the 2 whelks around the marinas. Differences in biological response to TBT were observed between the 2 whelk species: S. haemastoma had higher levels of organotins than H. trunculus in most study sites, which may be related to different sensitivity or accumulation rates. In S. haemastoma a male-biased sex ratio was revealed around the old Tel Aviv marina, which may be derived from either female mortality or from a complete sex change in some females. Further development of marinas at coastal resorts is undesirable, certainly in the absence of regulations limiting the use of TBT-based antifoulants, and the establishment of such regulations is highly recommended.