1999 Fiscal Year Final Research Report Summary
Caprella watch : new approach for monitoring butyltin levels in the shallow water ecosystem
| Project/Area Number |
09680503
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Environmental dynamic analysis
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| Research Institution | The University of Tokyo |
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Principal Investigator |
TAKEUCHI Ichiro The University of Tokyo, Ocean Research institute, Assistant Professor, 海洋研究所, 助手 (30212020)
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| Co-Investigator(Kenkyū-buntansha) |
TANABE Shinsuke Ehime University, Center for Marine Environmental Studies, Professor, 沿岸環境科学研究センター, 教授 (60116952)
MIYAZAKI Nobuyuki The University of Tokyo, Ocean Research institute, Professor, 海洋研究所, 教授 (40101464)
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| Project Period (FY) |
1997 – 1999
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| Keywords | acute toxicity / butyltins / Caprella / monitoring / seawater / shallow water ecosystem |
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| Research Abstract |
The wide impact of tributyltin (TBT) on non-target organisms has led several developed countries to place restrictions on the use of TBT as an antifouling agent for coastal boats and aquaculture beds. A comparative study on the butyltin levels in various organisms showed that marked bioaccumulation occurs in certain lower trophic levels ; i.e., from seawater to phytoplankton and into caprellid amphipods, Caprella spp. Caprella spp., which inhabit algal communities and aquaculture beds in the subtidal zone, are small crustaceans with reduced movement ability and a shortened life-span of less than 3 months. These characteristics indicate that Caprella spp. may be well-suited for monitoring butyltin residue changes over small spatial and temporal scales. Thus, we propose the suitability of using Caprella spp. to monitor temporal and spatial changes in baseline concentrations of butyltins. We compared the acute toxicity of caprellid and gammarid amphipods, both collected from the shallow water ecosystem of Otuschi Bay. The results show LCィイD250ィエD2 at 20℃ after 2 days of caprellids in 1.2-6.6 mg TBT/L are significantly lower than gammarids in 17.8-23.1 mg TBT/L. We have collected Caprella spp. from various areas along Japanese coasts since 1997. The preliminary results on the BTs (TBT, DBT and MBT) indicate that BTs vary from 1 ng/g wet weight in C. penantis R-type from Tobishima Island in the Sea of Japan to 466 ng/g wet weight in C. decipiens from Amakusa Islands, western Kyushu. This indicates that the difference of BTs in Caprella spp. is in the range of at least 500 times along Japanese coasts. The above results indicate that Caprella watch is a useful approach for monitoring butyltin residues in the shallow water ecosystem.
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