Butyltin accumulation in marine bivalves under field conditions in Taiwan

This study aimed to characterize the butyltin bioaccumulation in a simple food chain under varied conditions. Significant trophic level magnification factors of tributyltin (21.5–1546) were observed in two filter-feeders, oysters (Crassostrea gigas) and mussels (Perna viridis), in an environment with low tributyltin pollution levels (0.4–13.1 ng L−1 as tin). Both of these bivalve species showed higher bioaccumulation factors (BAFs) of tributyltin under low pollution levels, while smaller magnification factors (5.4–6.4), an up-regulated tributyltin metabolism and smaller BAFs of tributyltin were found in oysters at higher tributyltin pollution levels (39.6–99.3 ng L−1 as tin). Unlike oysters, mussels cannot up-regulate their tributyltin metabolism, which caused a dramatic change in butyltin accumulation between oysters and mussels as tributyltin pollution levels increased. In addition, higher BAF values of tributyltin were also obtained under the water summer conditions when higher temperatures and phytoplankton contents, and lower tributyltin pollution levels were observed.