Organotin levels in the Ria Formosa lagoon, Portugal

Organotin concentrations were measured in water, sediments and clams (Ruditapes decussatus) from 11 sites in the Ria Formosa lagoon, Portugal, in 1992-93. Results showed a marked spatial pattern of tributyltin (TBT) and dibutyltin concentrations. The highest organotin concentrations were observed at Olhao (site 5), where the most important fishing harbour of the Southern coast of Portugal is located. Results indicated that fishing vessels, moored in the harbour at Olhao (site 5), were the major source of organotin contamination to the lagoon. No significant seasonal trend was observed, suggesting a continuous input of organotin compounds throughout the year. In several areas of the lagoon the TBT burdens in R. decussatus could have deleterious developmental effects. Copyright (C) 2002 John Wiley Sons, Ltd.