熱帯海域における酸素不足地帯の拡大
Lothar Stramma1, Gregory C Johnson, Janet Sprintall
1Institut für Meereswissenschaften an der Universität Kiel (IFM-GEOMAR), Düsternbrooker Weg 20, 24105 Kiel, Germany. lstramma@ifm-geomar.de
まとめ
海洋の酸素レベルは低下しており,熱帯海の酸素不足地帯が拡大しています. この膨張は,溶けた酸素の減少により,海洋生態系と沿岸経済を脅かしている.
科学分野:
- 海洋学 海洋学とは
- マリン・バイオロジー マリン・バイオロジー
- 気候科学 気候科学
背景:
- 酸素が少ない水域は,中程度の深さの熱帯海に多く見られる.
- 低毒地帯は,移動性マクロオーガニズムに影響を及ぼし,海洋生態系に大きな影響を及ぼします.
- 地球温暖化により,海洋の溶けた酸素がさらに減少すると予測されています.
研究 の 目的:
- 熱帯海域における溶けた酸素濃度の50年連続を構成する.
- 過去50年にわたる酸素濃度の変化を分析する.
- 低酸素地帯の垂直拡大を調査する.
主な方法:
- 過去の溶解酸素データベースを最近の測定値で拡張する.
- 選択された熱帯海洋地域の溶けた酸素濃度データを分析する.
- 酸素の動向を追跡するために50年間のタイムシリーズを作成します.
主要な成果:
- 東部熱帯大西洋と赤道太平洋で観測された中程度の深さの低酸素地帯の垂直拡大.
- 溶解した酸素の減少率は,300〜700m層で,年間0.09〜0.34マイクロモール/キログラムです.
- 過去50年間,海洋の溶解酸素の有意な減少.
結論:
- 熱帯海の低酸素地帯は,垂直的に拡大しています.
- 酸素濃度の低下は,海洋生物と沿岸地域の経済に脅威をもたらしています.
- 観測された傾向は,海洋酸素の減少に関する気候モデルの予測と一致しています.
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