High mortality of the larvae of the common mussel at low concentrations of tributyltin

Abstract

Laboratory reared veliger larvae of the common mussel Mytilus edulis were grown for 15 days in filtered seawater containing 10 μg l −1, 1 μg l −1 and 0.1 μg l −1 tributyltin oxide (TBTO), the biocide in recent antifouling paint formulations. No larvae survived longer than 5 days in 10 μg l −1 TBTO or 10 days in 1 μg l −1 TBTO. Approximately half the larvae subjected to 0.1 μg l −1 TBTO were dead by day 15 (approximate 15 day LC 50 = 0.1 μg l −1 TBTO) and most of the surviving larvae were moribund and had grown significantly more slowly than controls. It is noted that current recorded levels of TBT at several UK estuarine sites are higher than 0.1 μg l −1 and there has therefore probably been a high mortality of mussel larvae at such sites. The results are discussed in relation to the reported short-term toxicity of organotins to other marine organisms and the value of carrying out longer-term tests at low levels of TBT is pointed out.