Isotope tracking of migration in marine fish

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K20495
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 64040:Social-ecological systems-related
• Research Institution: Chuo University (2020-2021); Japan Agency for Marine-Earth Science and Technology (2019)
• Principal Investigator: Matsubayashi Jun 中央大学, 理工学部, 助教 (30756052)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: アイソスケープ / 回遊推定 / 炭素安定同位体比 / 放射性炭素同位体比 / 窒素安定同位体比

Outline of Final Research Achievements

This study developed new methods to infer the ocean migration of highly migratory marine fish using spatial distributions of isotope ratios (isoscapes) of stable nitrogen and radiocarbon. We generated an isoscape of nitrogen stable isotope ratios in the northern north Pacific, and estimated migration histories of spawning chum salmon caught in several rivers in northern Japan. The isotope tracking successfully reproduced known migration pattern of chum salmon. Furthermore, our analysis suggested that the chum salmon migrate into the continental shelf of eastern Bering Sea just before they come back to Japanese coast, which was not recognized as an important habitat of this species in previous researches. We also generated isoscape of radiocarbon using existing data in global ocean, which can be a useful tool to estimate latitudinal migration of marine animals.

Free Research Field

同位体生態学

Academic Significance and Societal Importance of the Research Achievements

本研究で開発した回遊経路推定手法は、電子タグなどを用いずに魚類の回遊経路推定を可能とする。これは水産物の資源状況の把握やトレーサビリティーを改善するうえで極めて有用な手法であり、今後より簡便に分析を実施する環境を整えることで、水産資源に関する研究を大きく発展させることが期待される。