Abstract
Reproductive performance was measured in ostrea edulis exposed to tributyl tin (TBT)- based antifouling paint leachates for 75 days. Larval production was inhibited by low (0.24 \mug l-1TBT) and high (2.6\mug l-1TBT) concentrations of TBT. Histological examination of the gonad showed normal development in the control animals, a predominance of maleness in the low TBT-treated animals and little or no gonadal differentiation at the high TBT concentration. The results are discussed in relation to field observations of wild populations of O. edulis in clean and TBT-contaminated locations. A variety of commercially-important bivalve spat were exposed for seven weeks to two concentrations of organotin leachates. At0.24 \mug l-1TBT growth of Crassostrea gigas, Mytilus edulis and Venerupis decussata was severely reduced, but in Ostrea edulis and V. semidecussata weight increase was similar to control values. At2.6 \mug l-1TBT growth of all species was completely inhibited and mortalities were high; all M. edulis had died by day-14. In a further experiment, Crassostrea virginica spat were exposed to solutions of bis (tributyl tin) oxide. A reduced weight gain was observed at2.0 \mug l-1TBTO and growth at0.2 \mug l-1TBTO was similar to control values.