Chronic embryo-larval toxicity of tributyltin (TBT) to the hard shell clam Mercenaria mercenaria

Abstract

Fertilized clam eggs Mercenaria mercenaria were exposed to bis(tributyl)tin oxide (TBT) dissolved in seawater. Dosing protocol was daily renewal of static solutions. One set of M. mercenaria larvae was exposed for 14 d. A second group ('recovery group') was exposed to all TBT concentrations for the first 5 d of development and then maintained in uncontaminated seawater for the next 9 d) At concentrations tested, TBT had 2 main effects: 1) mean valve length of veligers and postlarvae consistently declined with increasing TBT exposure, and 2) veligers in exposures of 100 ng 1-1 and greater did not develop to pediveligers within the 14 d exposure period.