Contamination of the coastal waters of Bermuda by organotins and the triazine herbicide Irgarol 1051

A study of the distribution of the `booster' biocide 2-methylthio-4-tert-butylamino-6-cyclopropyl amino-s-triazine (Irgarol 1051) was carried out in the coastal waters of Bermuda. Irgarol 1051 concentrations (as determined by GC/MS) up to 590 ngl-1 have been measured within Hamilton Harbour. The data presented herein unequivocally demonstrate contamination of the coastal system of Bermuda by Irgarol 1051. Concurrently, TBT concentrations were measured and results indicate that levels are falling through legislated changes in antifouling treatments, from 220 ngl-1 in 1990 to <20 ngl-1 (as Sn) by 1995, in the open water area of Hamilton Harbour. Concentrations of TBT immediately offshore from a boatyard were found to be >600 ngl-1 (Sn), indicating continuing release due to painting operations and sediments in the area.