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[D-2.3 Bioaccumulation of Hazardous Chemicals in Bottom Fish Species by the Benthic Food Chain]

[Contact Person]

Hisashi Yamada
Director
Environment Conservation Division, National Research
Institute of Fisheries Science, Fisheries Agency.
Nagai 6, Yokosuka, Kanagawa, 238-03, Japan
Tel:+81-468-56-2887 Fax:+81-468-56-3075
E-mail:yamaq@nrifs-a.affrc.go.jp

[Total Budget for FY1995-FY1997]

41,379,000 Yen (FY1997;12,573,000 Yen)

[Abstract]

The bioaccumulation of dioxins (PCDDs and PCDFs), coplanar- PCB (Co- PCB) and organotins (TBT and TPT) in higher trophic organisms through the benthic food chain was studied with the field survey and the rearing experiment using polychaete.

The ratios of concentration of dioxins, Co-PCB, TBT and TPT in organisms to those in sediments were determined in the several coastal waters. The ratios for Co-PCB, TBT and TPT were larger than 1, however, the ratios of dioxins were smaller than 1. These results suggested that Co-PCB, TBTand TPT were accumulated in bottom fish from sediments.

The concentrations of Co-PCB and TPT were increased gradually with becoming higher trophic level of organisms in the food chain. On the other hand, dioxins and TBT concentrations in organisms were not related to the trophic level. It was recognized from these results that the hazardous chemicals having the larger biomagnification factor (BMF) were able to significantly accumulated in the higher trophic organisms through the food chain.

Rearing experiments using polychaete showed that BMFs of PCDDs and PCDFs were smaller than 1, however those of Co-PCB, TBT and TPT were larger than 1. It was obvious that Co-PCB, TBT and TPT were accumulated in polychaete from sediments. These results also suggested that polychaete played an important role in the transfer of chemicals from sediments to the higher trophic organisms.

[Key Words]

Bioaccumulation, Food chain, Organotins, PCDDs, PCDFs, Coplanar-PCB