Imposex and organotin body burden in the dog-whelk (Nucella lapillus L.) along the Portuguese coast

Nucella lapillus imposex-superimposition of male characters onto prosobranch (a subclass of gastropod molluscs) females-and organotin female body burden were surveyed on the Portuguese coast, from Vila Praia de (A) over cap ncora (northern limit) to Praia da Luz (southern limit), at 17 sampling stations, between May and August 2003. The vas deferens sequence index (VDSI), the relative penis size index (RPSI), the percentage of females affected with imposex (%I) and the percentage of sterile females (%S) were used to assess the level of imposex at each site. VDSI, RPSI and %I were 0.20-4.04, 0.0-42.2% and 16.7-100.0%, respectively. Sterile females were found at stations 2(6.2%), 5(4.0%) and 7(5.0%). Tributyltin (TBT) and dibutyltin (DBT) female body burdens were 23-138 and < 10-62 ng Sn/g dry weight, respectively. TBT female body burden was significantly correlated with RPSI and VDSI [Spearman rank order linear correlation: RPSI vs TBT body burden (b.b.) r = 0.71, p < 0.01; VDSI vs logTBT body burden r = 0.71, p < 0.01]. Imposex and TBT b.b. were highest at sites located in the proximity of harbours, where TBT leaching from antifouling paints is more intense owing to the high concentration of ships and dockyard activities. Copyright (c) 2005 John Wiley & Sons, Ltd.