SURVEY OF BUTYLTIN CONTAMINATION IN PORTUGUESE COASTAL ENVIRONMENTS

Butyltin compounds (MBT, DBT and TBT) in intertidal sediments collecte d in four different Portuguese coastal environments have been measured in order to evaluate the extent of contamination. The sites chosen we re the Rias of Aveiro and Faro, and the Sado and Tejo estuaries. These zones were traditional areas for shellfish production in the recent p ast, but the effects of industrial development have caused a deteriora tion of the environment. Specific contaminations were derived from the harbour (commercial and/or fisheries) and shipyard activities, result ing in a release of TBT and causing the oyster populations of the abov e mentioned estuaries to almost disappear. Results presented in this s tudy give a survey of TBT contamination levels found in the four areas . The paper discusses the importance of the pollution in comparison wi th other European coastal areas.