TBT pollution in Tunisian coastal lagoons as indicated by imposex in Hexaplex trunculus (Gastropoda: Muricidae)

Abstract

1 - Most of the shipping traffic in Tunisia comes from foreign countries that already enforced tributyltin (TBT) regulation.2 - Local and imported antifouling paints in Tunisia did not contain TBT.3 - Actual TBT contamination in Tunisia is the result of an old/historical pollution events.4 - Here we report data on imposex in Hexaplex trunculus from three Tunisian lagoons. This gastropod, which locally has fishery great commercial value, is currently used mostly for monitoring TBT effects in transitional and marine waters in the Mediterranean Sea.5 - Our results showed a decrease of imposex in Bizerta and in Northern Tunis lagoons, whilst in the southernmost lagoon of Boughrara imposex has significantly increased.6 - The effect of specimen size and reproductive activity on penis length variation in males and on the relative penis length index was validated.7 - Overall, we found that TBT is still a significant pollutant in the Tunisian waters, which requires further studies on the contamination causes.