Abstract
Concentrations of tributyltin (TBT) and triphenyltin (TPT) compounds were determined in seawater, bottom sediments and fish and shellfish at various trophic levels in the marine benthic food web collected in Japan Sea to clarify the difference in the bioaccumulation pattern between TBT and TPT in the deep sea ecosystem. TBT was detected in all samples: 0.3-0.8 ng/l for the seawater, 4.4-16 ng/g-dry for the sediment and 1.8-240 ng/g-dry for various kinds of organisms. This deep seawater concentration is lower than the coastal water concentrations. Concentration of TPT in seawater was less than our detection limit (0.9 ng/l), but it was 3.9-12 ng/g-dry for the sediment and 5.0-460 ng/g-dry for the organisms. TPT concentrations of the sediments and organisms were similar to those reported in Tokyo Bay in 1999. TPT concentration becomes higher as the trophic level increases, suggesting the bioaccumulation of TPT through the food web. However, no such trend was observed for TBT. The higher TPT concentration in the benthic organisms than in the sediments implies that TPT can be transferred to benthic organisms from bottom sediments and that the sediments can act as a secondary contamination source of TPT.
