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

The use of tributyltin (TBT)-based antifouling paints is unregulated in Isr ael, and levels of contamination are high along the Mediterranean coastline there. This is indicated by concentrations of butyltins found in the tissu e, and by imposer in the whelks Stramonita haemastoma and Hexaplex trunculu s. Both the old (since 1974) and new (since late 1995) marinas we studied a re hotspots of pollution. Imposer indices were very high at the old marina (RPSI > 100, VDSI4 to 5); all female H. trunculus and some S. haemastoma we re sterile within a distance of ca 1 km from it. The new marina offered a u nique opportunity to witness the rapid and intense response of the whelks t o TBT pollution in an open coastline. Despite a marked decrease in levels o f contamination at distances of 1 to 2 km from both marinas, there were nev ertheless detectable levels of butyltins sufficient to cause imposer in ref erence sites far from high shipping activity. There is evidence that TBT co ntamination 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 le vels of organotins than H, trunculus in most study sites, which may be rela ted 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 anti foulants, and the establishment of such regulations is highly recommended.