漁業は,搾取された種の豊富な多様性を高めます
Chih-Hao Hsieh1, Christian S Reiss, John R Hunter
1Scripps Institution of Oceanography, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0202, USA.
Nature
|October 20, 2006
まとめ
漁業は,未開拓の魚種とは異なり,搾取された魚種の集団の変動性を増幅します. 年齢構造の断片化によるこの増加した変動は,魚類の崩壊を防ぐために,漁業管理に対する予防的アプローチを必要とします.
科学分野:
- 海洋生態学 海洋生態学とは
- 漁業科学 漁業科学 漁業科学
- 人口の動態
背景:
- 漁業の影響と環境の変動を区別することは,効果的な漁業管理に不可欠です.
- 搾取された魚群は,搾取されていない魚群と比べて,しばしば異なる人口動態を示しますが,これらの影響を分離することは困難です.
研究 の 目的:
- 魚の個体数に対する漁業の影響と,環境の変動の影響を区別する.
- 漁業が魚類の蓄積量の時間的変動にどのように影響するか調査する.
主な方法:
- 同じ海洋環境における,利用された魚群と未利用の魚群の間の時間的な豊富さの変動の比較.
- カリフォルニア協同海洋漁業調査 (CalCOFI) の50年間のラバル魚の調査データを活用したものです.
- 長期の生態学的実験の枠組みの中で,漁業を処理効果として分析し,生命史,豊富さ,生態学的特徴,および系統遺伝を制御します.
主要な成果:
- 漁獲されている魚種は,漁獲されていない魚種と比較して,大量に時間的な変動が著しく高くなっています.
- この高い変動性は,様々な生物学的および生態学的要因を考慮した後でも持続します.
- 漁業が誘発した,搾取された集団の年齢構造の断片化は,環境変化に対する回復力を低下させ,多様性の増加の主な原動力であるようだ.
結論:
- 漁業は,魚群のサイズを枯渇させるだけでなく,人口変動を拡大させ",二重の危険"のシナリオを生み出します.
- 効果的な漁業管理には,総バイオマスと年齢構造の多様性の保全の両方を考慮する必要があります.
- 漁業によって引き起こされる集団の変動に関連するリスクを軽減し,株の崩壊を防ぐために,予防管理戦略は不可欠です.
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