Elucidation of radiocesium contamination levels in fishes with different ecological characteristics: toward the restoration of Fukushima's fisheries

2019 Fiscal Year Final Research Report

• Project/Area Number: 16H06199
• Research Category: Grant-in-Aid for Young Scientists (A)
• Allocation Type: Single-year Grants
• Research Field: Aquatic bioproduction science
• Research Institution: Fukushima University
• Principal Investigator: Wada Toshihiro 福島大学, 環境放射能研究所, 准教授 (90505562)
• Project Period (FY): 2016-04-01 – 2020-03-31
• Keywords: 原発事故 / 漁業復興 / 放射性セシウム / 海水魚 / 淡水魚 / 食物網 / 魚類生態

Outline of Final Research Achievements

The aim of this study is to elucidate the radiocesium contamination mechanisms of marine and freshwater fish, and to contribute the restoration of Fukushima’s fisheries based on the scientific knowledge disseminated through scientific papers, international conference and local dialogue meeting etc. This study has revealed that radiocesium concentrations in marine fish were constantly low, while those in freshwater fish inhabiting water bodies near the Fukushima Dai-ichi Nuclear Power Plant were still extremely high in terms of Japanese food safety standard. Continuous radiocesium uptake through food web were inferred to be the primarily cause of the higher radiocesium contamination levels in freshwater fish.
The obtained results were frequently disseminated through international journals, local dialogue meetings, and discussions at the Fukushima’s local fisheries restoration council, which have contributed the restoration of Fukushima’s fisheries.

Free Research Field

水産学、魚類生態学、水圏放射生態学

Academic Significance and Societal Importance of the Research Achievements

福島原発事故に伴い放出された放射性セシウム（Cs）による海水魚および淡水魚の放射能汚染の影響は長期化しており、各種の生態特性に応じたCs汚染メカニズムの解明に基づく福島県の漁業復興が関連業界や学術界から求められている。本研究では、近年、海産魚類のCs汚染レベルが一様に低いことを示した。一方、原発周辺の渓流域や貯水池に生息する淡水魚のCs濃度が海水魚に比べて依然として高く、淡水魚では、食物網を介したCsの取込が継続している実態を明らかにした。