サブ熱帯海における酸素の純生産
Stephen C Riser1, Kenneth S Johnson
1School of Oceanography, University of Washington, Seattle, Washington 98195, USA. riser@ocean.washington.edu
Nature
|January 19, 2008
まとめ
栄養価が低い地域の海洋プランクトンは,酸素と炭素の純生産者である. 連続した酸素増加は,冬の混合イベントよりも低くなると,一貫した純オートロフィーを明らかにし,エピソード的生産理論に挑戦します.
科学分野:
- 海洋学 海洋学とは
- 海洋生態学 海洋生態学
- バイオジオケミストリー バイオジオケミストリー
背景:
- 栄養価が低い海洋地域は,世界の海洋表面の80%を占めています.
- 酸素と炭素循環におけるプランクトンコミュニティの役割は不明である.
- ボトル実験 (純消費) と地化学データ (純生産) の間で矛盾する証拠が存在する.
研究 の 目的:
- 亜熱帯の渦中における純酸素と炭素のバランスを調査する.
- 直接的な測定と地化学的証拠の間の不一致を解決するために.
- 連続的なプライマリ生産とエピソード的プライマリ生産の役割を評価する.
主な方法:
- 3年間にわたってプロファイリングフロートに酸素センサーを配置.
- 北太平洋と南太平洋の亜熱帯回転における酸素濃度の監視.
- 水柱の混合と地域生産に関連した酸素動態の分析.
主要な成果:
- 冬の混合イベントは,上部水柱を均質化し,低酸素につながります.
- 混合層の下では,連続した,ほぼ恒常的な酸素増加率が観察されます.
- この割合は,コミュニティの純生産の独立した測定値と一致しています.
結論:
- サブ熱帯の渦巻の生態系は,年間を通して固定炭素の純生産者 (純オートロフィック) である.
- 一時的な出来事ではなく,継続的な生産が,陽性酸素の生産を維持します.
- この発見は,これらの広大な海洋地域における一貫した純自栄養状態を裏付けている.
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