Constructing models for predicting changes in distributions of large migratory fishes in response to ocean warming

2023 Fiscal Year Final Research Report

• Project/Area Number: 18KK0293
• Research Category: Fund for the Promotion of Joint International Research (Fostering Joint International Research (B))
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 63:Environmental analyses and evaluation and related fields
• Research Institution: The Graduate University for Advanced Studies (2023); National Institute of Polar Research (2018-2022)
• Principal Investigator: Watanabe Yuuki 総合研究大学院大学, 統合進化科学研究センター, 教授 (60531043)
• Co-Investigator(Kenkyū-buntansha): 中村 乙水 長崎大学, 海洋未来イノベーション機構, 助教 (60774601) ; 松本 瑠偉 一般財団法人沖縄美ら島財団(総合研究センター), 総合研究センター 動物研究室, 上席研究員 (90816430)
• Project Period (FY): 2018-10-09 – 2024-03-31
• Keywords: 行動生態 / 環境適応 / 水温 / 魚類

Outline of Final Research Achievements

Swimming behavior, ambient water temperature, and body temperature of large migratory fishes were measured using bio-logging techniques and analyzed in combination with metabolic rate data. Blue sharks kept their body temperature within a certain range by using thermal inertia caused by their large bodies and by constantly repeating dives. Greenland sharks in the Arctic had low metabolic rates due to their low body temperatures and were able to maintain a positive energy balance with a small amount of food. Comparisons of metabolic rates among fish species showed evidence of evolutionary modifications of temperature effects on metabolic rates in teleosts (bony fishes), but not in elasmobranchs (sharks and rays). It is possible that elasmobranchs may be more sensitive than teleosts to changes in water temperature associated with climate change, leading to larger changes in their distributions.

Free Research Field

海洋生物学

Academic Significance and Societal Importance of the Research Achievements

大型回遊魚がなぜ深い潜水を繰り返すのかについて、これまで様々な議論があったが、明瞭な答えは出ていなかった。本研究では、サメの深い潜水には獲物の探索と体温調節という2つの機能があることがわかった。また、魚類の水温適応が硬骨魚類と軟骨魚類で異なることが明らかになった。気候変動に伴う水温変化に対し、軟骨魚類の方が鋭敏に反応する可能性を示唆するもので、種の保全や水産資源管理に深い示唆を与える発見である。