ASSESSING THE IMPACT OF TIN AND TBT IN ESTUARIES AND COASTAL REGIONS

Demonstration of the toxic nature of tributyltin (TBT), particularly to molluscs, has led to restrictions on the uses of TBT in antifouling preparations in the UK, initially in an attempt to achieve an environmental quality target of 20 ng l-1, and subsequently one of 2 ng l-1. No equivalent target has been set for sediments and the bioavailability and effects of tin compounds associated with particulates are largely unknown. Results here demonstrate the exceptionally high bioavailability of sediment-bound TBT, relative to inorganic tin, notably among estuarine sediment-dwelling species such as clam Scrobicularia plana. Measurement of TBT-induced reproductive abnormalities (imposex) in dogwhelk Nucella lapillus provides an extremely specific and sensitive means of monitoring the biological impact of this contaminant in coastal waters. -from Authors