アップウォーリングによる近岸低酸素は,北東太平洋の生態系と海洋学的な変化を示唆しています
Brian A Grantham1, Francis Chan, Karina J Nielsen
1Washington State Department of Ecology, Coastal and Estuarine Assessment Unit, Olympia, Washington 98504, USA.
Nature
|June 18, 2004
まとめ
重度の低酸素,または低溶解酸素は,カリフォルニアの流れ系で大量死滅を引き起こしました. この前例のないイベントは,海洋環境の変化に関連しており,海洋生態系の気候変動に対する脆弱性を強調しています.
科学分野:
- 海洋生態学 海洋生態学とは
- 海洋学 海洋学とは
- 気候科学 気候科学
背景:
- 溶解酸素の不足 (低酸素症) は,世界の沿岸生態系と漁業を混乱させる.
- 栄養素の負荷が河口で低酸素を引き起こす一方で,開いた海岸の低酸素は,酸素が少ない深い水の上流と関連しています.
- アップウォーリングシステムは,世界の漁業にとって不可欠であり,低酸素への気候の影響を理解することは極めて重要です.
研究 の 目的:
- カリフォルニア流動系における重度の内棚低酸素症の前例のない発展を調査する.
- 大量死滅を含む,この低酸素現象の生態学的結果を決定する.
- 観測された低酸素を海洋学的条件の変化と気候の変動と関連付ける.
主な方法:
- 溶解酸素レベルを測定するためにクロスシェルフトランセクトの分析.
- カリフォルニア流水系内の水質と流れのモニタリング.
- 魚と無脊椎動物の死亡率を記録するための生態学的調査.
主要な成果:
- 2002年にカリフォルニア州内部の流れ系で発生した前例のない重度の低酸素症 (70m以下).
- 亜北極の水の異常な強い流れは,低酸素の発生と相関していた.
- 海洋魚と無脊椎動物の大量死滅が観察されました.
結論:
- 内部シェルフの生態系は,海洋条件の変動に対して非常に敏感です.
- 気候変動は,低酸素症の発生頻度と重症度を悪化させる可能性があります.
- アップウォーリング駆動型低酸素症は,海洋コミュニティと漁業の持続可能性に重大な脅威をもたらします.
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