Population structure of greater amberjack in the East China Sea using biologging and molecular phylogenetic analysis

2023 Fiscal Year Final Research Report

• Project/Area Number: 21H02270
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 40030:Aquatic bioproduction science-related
• Research Institution: Nagasaki University
• Principal Investigator: Kawabe Ryo 長崎大学, 海洋未来イノベーション機構, 教授 (80380830)
• Co-Investigator(Kenkyū-buntansha): 阪倉 良孝 長崎大学, 水産・環境科学総合研究科(水産), 教授 (20325682) ; 中村 乙水 長崎大学, 海洋未来イノベーション機構, 助教 (60774601)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: カンパチ / 集団構造 / バイオロギング / 回遊 / 東シナ海 / 分子系統 / 黒潮

Outline of Final Research Achievements

Surveys conducted around Taiwan and in southern Kagoshima revealed that the adult greater ambarjack in the East China Sea do not migrate on a large scale like yellowtail, but have spawning grounds in the vicinity of the Kuroshio, forming a migration ring closely associated with the Kuroshio and its branching currents. For this species, the Kuroshio is thought to transport juveniles from upstream to downstream, facilitating interactions between populations within the basin, and at the same time acting as a barrier to interactions with other areas of the sea. Comparison of spawning grounds with yellowtails showed that the spawning grounds of both species overlap around the continental shelf slope area at the southern end of the East China Sea from January to February. It is the reason for the natural hybridization individuals of both species was due to an overlap in spawning time and space as the spawning grounds expanded to the south with the recent increase in yellowtail abundance.

Free Research Field

魚類回遊生態学

Academic Significance and Societal Importance of the Research Achievements

東シナ海産カンパチは、親魚がそれぞれの固有の生息地を有する一方で、卵仔稚魚は黒潮によって広域に分散拡散することで、東シナ海で単系統となる集団構造が形成されることが明らかとなった。これが本研究の学術的意義となる。また、東シナ海には地域ごとに固有の産卵場が国を跨いで形成されることから、東シナ海産カンパチの個体数と遺伝資源の両方を保全するには、国際的な管理体制（例えば日本と台湾）を整備することが肝要となる。これが本研究の成果に立脚した社会的意義となる。