Beach tar contamination on the Qatari coastline of the Gulf

Beach tar concentrations were measured along the Qatari coastlines. Tar con centrations, collected from 11 locations, varied in space and time with val ues ranging between 2 and 1132 g m(-1) (average 290 g m(-1)) of beach front . Tar deposition was maximum following the Gulf War oil spill, especially a long the northwestern (average 723 g m(-1)) and northern coasts (average 62 0 g m(-1)). With the exception of higher levels off Saudi Arabia and Oman, the levels of beach tar around Qatar appear to be within the range of previ ously recorded Gulf values. The eastern coast appears to be receiving fresh tar in lower amounts (average 150 g m(-1)) than the western coast (average 304 g m(-1)), where older tar from earlier spills still persists in large quantities. The application of strict regulations on ballast water disposal in the Gulf led to a clear declination in tar deposition since 1993, reach ing baseline limits in some locations. (C) 1999 Elsevier Science Ltd.