Can highly degradable antifouling substances be said to be environmentally friendly? Risk Assessment of Sensitive Fishery Species

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K17904
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 64010:Environmental load and risk assessment-related
• Research Institution: Fisheries Research and Education Agency
• Principal Investigator: Kono Kumiko (池田久美子) 国立研究開発法人水産研究・教育機構, 水産技術研究所(廿日市), 主幹研究員 (10371973)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 防汚物質 / 二枚貝幼生 / リスク評価

Outline of Final Research Achievements

As a result of investigating the annual changes in DCOIT contamination in Hiroshima Bay, the highest concentration of DCOIT in seawater was close to the lowest concentration of DCOIT effect on bivalve larvae. In addition, the toxicity of octylamine, a degradation product of DCOIT, to bivalve larvae is less than 1/100,000 of DCOIT, and the contribution of degradation products to the toxicity of DCOIT on bivalve larvae is extremely low in assessing the risk of DCOIT on bivalve larvae. As a result of toxicity tests conducted at 19℃～31℃, the malformation rate of larvae was lowest at 22℃ for clams and 25℃ for oysters, and the malformation rate tended to increase with increasing water temperature.

Free Research Field

環境毒性学

Academic Significance and Societal Importance of the Research Achievements

本研究では、分解性が高いものの、その影響が懸念されている、防汚物質4,5-dichloro-2-n-octyl-4-isothiazolin-3-one (DCOIT）について、近年、資源量の減少が報告されている二枚貝幼生に対するリスク評価を行うことを目的とし、アサリ胚～幼生期毒性試験法を確立して二枚貝幼生に対するDCOITおよびその分解産物の毒性や水温との複合影響を把握すると共に、マガキおよびアサリ幼生の分布域および移動経路におけるDCOITの汚染実態を明らかにした。本研究の成果は、感受性の高い水産重要種と防汚物質の共存を目指した、防汚物質使用の適正化に関する提言に繋がるものと期待される。