Development of novel environmental monitoring techniques using seabirds as bioindicators of marine contaminant

2023 Fiscal Year Final Research Report

• Project/Area Number: 19KK0159
• 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 40:Forestry and forest products science, applied aquatic science, and related fields
• Research Institution: University of Tsukuba
• Principal Investigator: Shoji Akiko 筑波大学, 生命環境系, 准教授 (30792080)
• Co-Investigator(Kenkyū-buntansha): 新妻 靖章 名城大学, 農学部, 教授 (00387763) ; 徳永 幸彦 筑波大学, 生命環境系, 准教授 (90237074)
• Project Period (FY): 2019-10-07 – 2024-03-31
• Keywords: 海洋生態学 / 水銀 / 海洋汚染 / バイオロギング / 保全 / 海鳥

Outline of Final Research Achievements

To investigate the intercontinental transport of the marine pollutant mercury, we conducted behavioral ecology studies using seabirds, top predators in marine ecosystems, as model organisms. Our research focused on Rhinoceros Auklets from Middleton Island, Alaska, and Teuri Island, Hokkaido. We conducted chemical analyses of tissues collected from the birds. During the non-breeding season, we found that Rhinoceros Auklets from Teuri Island wintered in nearby Japanese waters, exhibiting a figure-eight movement pattern. In contrast, those from Middleton Island extensively utilised regions from offshore California to the North Pacific Gyre. Our analysis revealed a significant correlation between anthropogenic mercury emissions and mercury accumulation in these seabirds. This finding suggests that mercury released into the environment is associated with the levels of mercury found in the resident seabird populations.

Free Research Field

行動生態学

Academic Significance and Societal Importance of the Research Achievements

本研究により、環境中に排出される水銀汚染量と排出源に近い海域を利用する海鳥の体組織内水銀濃度との関連が明らかになり、水銀の輸送メカニズムの理解に寄与する知見を得ることができた。また、空間解析を用いた種間比較の結果から、同じ餌種を利用する場合でも海域の違いが水銀曝露量に影響すること、さらに同じ餌や海域を利用しても種間で曝露量に違いが出ることが明らかになった。これらの結果は、生態系保全地域の設定、汚染ホットスポットの可視化、生体への影響評価などへの応用が期待できる。