ORGANIC POLLUTANTS IN MUSSELS AND SEDIMENTS OF THE COASTAL WATERS OFFPERTH, WESTERN-AUSTRALIA

The results of a survey of organic pollutants in the marine sediments and the common mussel, Mytilus edulis, from the southern metropolitan coastal waters off Perth are presented. Organophosphorus and organochl orine pesticides, polychlorinated biphenyls, aliphatic and polycyclic aromatic hydrocarbons and organotin compounds were analysed in surfici al (top 20 mm) sediments from 175 sites and in mussel tissue from 35 s ites over an area of 500 km(2). Detectable concentrations of pesticide s, polychlorinated biphenyls and aliphatic hydrocarbons were recorded at approx. 5% of the sediment. sites and 10% of the mussel sites. Cont amination was generally confined to areas within or immediately adjace nt to shipping facilities and marinas. By contrast, contamination of s ediments and mussels with polycyclic aromatic hydrocarbons and organot in compounds, particularly trlbutyltin, was widespread throughout the study area, Areas of highest contamination occurred in harbours and bo at mooring areas and along the eastern side of Cockburn Sound. Compari sons with the results of similar Australian and overseas studies indic ate that, in general, sediments and mussels from these waters are not significantly contaminated with pesticides, polychlorinated biphenyls or hydrocarbons. In contrast, elevated concentrations of tributyltin i n the sediments and mussels are amongst the highest recorded in Austra lia and, coupled with the known toxicity of this compound to marine an imals, are cause for major concern. The high frequency of imposer in t he neogastropod, Thais orbita, collected from the study area underline s this concern.