Contamination of Mediterranean (Côte dʹAzur) coastal waters by organotins and irgarol 1051 used in antifouling paints

A survey was recently conducted to investigate concentrations of selected antifouling agents in sub-surface waters from the Mediterranean (Côte dʹAzur) coastline. Substantial levels of tributyltin (TBT) and 2-methylthio-4-tert-butylamino-6-cyclopropylamino-s-triazine (Irgarol 1051) were detected in all marinas, with concentrations reaching 460 ng l−1 for TBT and 640 ng l−1 for Irgarol 1051. Triphenyltin (TPT) and the TBT degradation products (dibutylin (DBT) and monobutylin (MBT)) were also detected, but at lower concentrations than TBT. High ratios of TBT/DBT were recorded, which suggests recent inputs of the active biocide TBT. Despite restrictions on the use of organotin-based marine antifouling paints imposed in France in 1982 and throughout the Mediterranean in 1991, the concentrations encountered still represent an ecotoxicological risk. However, when compared with concentrations from our previous surveys, current contamination from TBT is substantially less than that recorded in October 1988. The levels of the antifouling triazine herbicide Irgarol 1051 are similar to those reported from a survey in 1992. Another triazine (terbutryn) was also encountered in a few marina waters, although the source of this compound is uncertain.