Overlooked process of land-ocean interactions: Quantitative evaluation on the impact of coastal landslide on marine ecosystems

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K19854
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 64:Environmental conservation measure and related fields
• Research Institution: Hokkaido University
• Principal Investigator: Nakaoka Masahiro 北海道大学, 北方生物圏フィールド科学センター, 教授 (90260520)
• Co-Investigator(Kenkyū-buntansha): 伊佐田 智規 北海道大学, 北方生物圏フィールド科学センター, 准教授 (80725359) ; 土井 一生 京都大学, 防災研究所, 准教授 (00572976)
• Project Period (FY): 2021-07-09 – 2024-03-31
• Keywords: 陸海相互作用 / 海岸地すべり / 沿岸生態系 / 土砂流入 / 漂泳生態系 / 藻場

Outline of Final Research Achievements

This study examines the impact of sediment supply by coastal landslides on coastal ecosystems in eastern Hokkaido. Continuous observations of coastal landslides revealed the complexity of spatiotemporal dynamics of sediment production and runoff due to concurrent multiple factors. Furthermore, broad and continuous observations in the coastal marine ecosystem suggested that small-scale landslides induced by wind and waves transport sediment to the sea surface, impacting particularly lower trophic levels of planktonic ecosystems. Continuous observations of seagrass/seaweed beds and species distribution modeling revealed that coastal landslides affect not only the distribution but also the life history of constituent species.

Free Research Field

海洋生態学

Academic Significance and Societal Importance of the Research Achievements

本研究の結果、海洋学的・地質学的プロセスが、海洋生態系や生物多様性の変動に大きな影響を与えることが判明した。このことは、気候変動による極端環境現象が今後多発することが予想される中で、防災と生態系・生物多様性保全という社会的なニーズの高い課題を統合的に扱うことの重要性を示すものである。今後、生態学分野と地質学分野の異分野協働研究による新たな学問領域の創設が期待される。