New Developments in Research on Land-Based Stressors Affecting Corals Considering Multiple Stress Factors

2023 Fiscal Year Final Research Report

• Project/Area Number: 22K14943
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 40030:Aquatic bioproduction science-related
• Research Institution: National Institute of Advanced Industrial Science and Technology
• Principal Investigator: Iijima Mariko 国立研究開発法人産業技術総合研究所, 地質調査総合センター, 研究員 (20915483)
• Project Period (FY): 2022-04-01 – 2024-03-31
• Keywords: サンゴ / 蓄積型栄養塩 / 底質

Outline of Final Research Achievements

Based on findings that phosphate directly inhibits the skeletal formation of coral polyps and accumulates in calcareous substrates, this study aimed to elucidate the impact of land-based stressors on coral growth. Specifically, the study focused on: 1) detailed analysis of land-based nutrient loads, including accumulated nutrients, 2) identification of acutely toxic substances in the substrate, and 3) elucidation of the molecular mechanisms by which phosphate affects skeletal formation. The research revealed high concentrations of adsorbed phosphate in areas like Sekisei Lagoon, where coral polyp skeletal formation and survival rates were found to decrease. Additionally, heavy metals were shown to negatively impact coral survival rates, and gene experiments confirmed a decrease in gene expression levels due to phosphate load.

Free Research Field

環境化学，環境生態学

Academic Significance and Societal Importance of the Research Achievements

本課題により陸域から海域への栄養塩や重金属の流入がサンゴ礁に与える影響を把握することで，陸域から海域への排出制限の閾値設定に貢献できるほか，石灰質の底質に吸着している蓄積型栄養塩においては陸域負荷の指標として用いることで環境保全政策の策定に貢献できることが期待される。このように沿岸域の陸域負荷のサンゴ礁生態系への実態を解明しサンゴ礁を保全するとともに，亜熱帯島嶼域における持続可能な地下水利用法を構築する上で欠かせない知見をもたらし，持続可能な社会システム構築の一助となるであろう。