TRIBUTYLTIN CONTAMINATION IN THE BAY OF B REST

The extent of tributyltin (TBT) contamination of the Bay of Brest, res ulting from the use of TBT-containing antifouling paints, has been ass essed from the results of analyses of more than 150 sediment and water samples taken during 1992-1994. As expected, TBT concentrations in se diments were highest (1-21 mu g . g(-1)) in areas close to the naval d ockyards, the commercial port and ship repair facilities, but were als o high at the marina despite the ban on TBT paint use on small boats. TBT was readily detectable in bottom sediments throughout the bay, eve n in the deeper regions. Concentrations of dissolved TBT showed the sa me pattern of distribution : high (5-50 ng . l(-1)) close to the ship facilities and marina and lower (1-5 ng . l(-1)) elsewhere. A simulati on model of TBT transport demonstrates that the contamination of the b ay results from three sources of TBT, the naval area, the commercial p ort and the marina. The factors likely to govern future levels of TBT pollution in the Brest area are discussed.