漁業における廃棄率と海鳥の集団の変化
Stephen C Votier1, Robert W Furness, Stuart Bearhop
1Institute of Biomedical and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK. s.votier@bio.gla.ac.uk
Nature
|February 20, 2004
まとめ
漁業による廃棄物は,海鳥にとって極めて重要です. 廃棄の減少は,特にサンディールが少ないと組み合わせると,グランドスクワが他の海鳥を捕獲し,個体群を脅かすことを強いることができます.
科学分野:
- 海洋生態学 海洋生態学とは
- 鳥の生態学 鳥の生態学とは
- 漁業科学 漁業科学 漁業科学
背景:
- 商業漁業の廃棄物は,世界中の多くの海鳥の種にとって重要な食糧源です.
- 廃棄物変動に対する海鳥のコミュニティの反応を予測することは,自然の生態学的変動のために複雑です.
- 北海漁業は,廃棄率に影響を及ぼす変化を経験しており,重要な海鳥集団に影響を与えています.
研究 の 目的:
- 漁業の廃棄物利用量と,北北海のスクア (Stercorarius skua) の利用量との関係を調査する.
- 廃棄量と獲物の利用可能性の変化が,グランドスクワの餌食行動に与える影響と,他の海鳥コミュニティに対する潜在的な脅威を評価する.
主な方法:
- 北北海の北部の長期データセットを利用した.
- 大スクワーの廃棄物利用と廃棄物の使用を分析した.
- 廃棄の減少とサンディール (Ammodytes marinus) の利用可能性に対する反応として,獲物を切り替える行動を調べた.
主要な成果:
- 漁業での廃棄物利用量と,スクワの廃棄物消費量との間には直接的な相関関係があることが判明した.
- 廃棄率が低下したときに,特にサンディルの利用率が低い場合,他の鳥に対する大スクワーの捕食の増加が観察されました.
- グレートスクワが獲物を切り替えることは,廃棄物の利用可能性に関連した重要な要因として特定されました.
結論:
- グレート・スクワは,選択的にゴミ収集を行い,漁業の廃棄物が少ないときに他の海鳥の捕食に切り替えます.
- 漁業の廃棄の減少は,グランドスクワーのような汎用種による捕食の増加によって,海鳥の個体群に潜在的な脅威をもたらします.
- 漁業と海鳥の保全のための管理戦略は,廃棄物利用によって影響される複雑な捕食者-獲物のダイナミクスを考慮する必要があります.
関連する概念動画
00:48Optimal Foraging
How animals obtain and eat their food is called foraging behavior. Foraging can include searching for plants and hunting for prey and depends on the species and environment.
01:50Threats to Biodiversity
There have been five major extinction events throughout geological history, resulting in the elimination of biodiversity, followed by a rebound of species that adapted to the new conditions. In the current geological epoch, the Holocene, there is a sixth extinction event in progress. This mass extinction has been attributed to human activities and is thus provisionally called the Anthropocene. In 2019 the human population reached 7.7 billion people and is projected to comprise 10 billion by...
02:04Conservation of Small Populations
Small population sizes put a species at extreme risk of extinction due to a lack of variation, and a consequent decrease in adaptability. This weakens the chances of survival under pressures such as climate change, competition from other species, or new diseases. Large populations are more likely to survive pressures such as these, as such populations are more likely to harbor individuals that have genetic variants that are adaptive under new stresses. Small populations are much less likely to...
02:07Conservation of Declining Populations
Conservation of declining population focuses on ways of detecting, diagnosing, and halting a population decline. The approach uses methods to prevent populations from going extinct.
02:31Habitat Fragmentation
Habitat fragmentation describes the division of a more extensive, continuous habitat into smaller, discontinuous areas. Human activities such as land conversion, as well as slower geological processes leading to changes in the physical environment, are the two leading causes of habitat fragmentation. The fragmentation process typically follows the same steps: perforation, dissection, fragmentation, shrinkage, and attrition.
01:26Derivatives: Problem Solving
Temperature-Dependent Growth of Brook TroutThe growth of brook trout is closely influenced by water temperature. Experimental data demonstrate how trout weight changes over a 24-day period in response to varying water temperatures. At lower temperatures, such as 15.5 degrees Celsius, brook trout show significant weight gain. However, as the temperature increases, the amount of weight gained steadily decreases. At the highest temperature measured, 24.4 degrees Celsius, trout experience a net...