相关实验视频
Updated: Feb 14, 2026

09:47
Spotting Cheetahs: Identifying Individuals by Their Footprints
Published on: May 1, 2016
15.4K
追踪渔业的全球足迹
David A Kroodsma1, Juan Mayorga2,3, Timothy Hochberg4
1Global Fishing Watch, Washington, DC 20036, USA. david@globalfishingwatch.org.
概括
渔船覆盖了一半以上的海洋, 全球渔业模式更多地受到假期和关闭的影响,而不是经济或环境变化.
科学领域:
- 海洋生态
- 渔业科学
- 海洋学
背景情况:
- 人类通过捕鱼对自然资源的剥削是普遍存在的.
- 渔业活动的全球足迹仍然不明确,且没有量化.
- 之前的数据集缺乏空间和时间分辨率来准确地绘制捕捞力度.
研究的目的:
- 量化工业渔业活动的全球动态足迹.
- 创建一个高分辨率的,动态的全球渔业活动地图.
- 分析影响全球渔业模式的因素.
主要方法:
- 处理了220亿个自动识别系统 (AIS) 消息.
- 在2012年至2016年间跟踪超过7万艘工业渔船.
- 开发了一个高分辨率的全球捕捞力度数据集.
主要成果:
- 工业渔业占全球海洋面积的55%以上.
- 渔业的面积是农业的四倍以上.
- 渔业模式对短期经济和环境变化的敏感性较低.
- 渔业模式对节假日和关闭等文化和政治事件作出了强烈反应.
结论:
- 工业渔业在全球范围内占有很大份额.
- 捕捞力度的分布受到以人为中心的因素而非仅仅是环境或经济因素的影响.
- 这项研究为了解和管理全球渔业影响提供了前所未有的解决方案.
相关概念视频
Global Climate Change
29.1K
Throughout its ~4.5 billion year history, the Earth has experienced periods of warming and cooling. However, the current drastic increase in global temperatures is well outside of the Earth’s cyclic norms, and evidence for human-caused global climate change is compelling. Paleoclimatology, the study of ancient climate conditions, provides ample evidence for human-caused global climate change by comparing recent conditions with those in the past.
29.1K
Introduction to Global Positioning System
609
The Global Positioning System (GPS) revolutionized positioning on Earth, providing precise location data through satellite ranging. The GPS system was developed in 1978 by the U.S. Department of Defense for military use, and it became available for civilian applications in 1983, transforming fields including navigation, fleet management, and time synchronization for telecommunications systems.GPS consists of satellites in medium Earth orbit, about 20,200 kilometers above the surface,...
609
Errors in Global Positioning System
364
Global Positioning System (GPS) technology has revolutionized navigation and positioning, but its accuracy is often compromised by various errors. These errors, stemming from environmental, satellite, and receiver-related factors, require careful mitigation to ensure reliable performance across applications.Atmospheric ErrorsGPS signals travel through the Earth’s ionosphere and troposphere, introducing delays which affect accuracy. The ionosphere is strongly influenced by charged particles,...
364
Global Regulatory Systems
732
Global regulatory systems in bacteria enable rapid and coordinated responses to environmental changes by integrating sensory inputs with gene expression, ensuring efficient adaptation to fluctuating conditions. Key global regulatory mechanisms include regulons, two-component systems, sigma factors, and secondary messengers.Regulons and Global RegulatorsA regulon is a collection of genes and operons controlled by a common global regulator. These regulators enable bacteria to prioritize resource...
732
Field Application of Global Positioning System
333
The Global Positioning System (GPS) has become an indispensable tool in fieldwork, offering unparalleled precision and efficiency for surveying, navigation, and infrastructure development. By harnessing signals from a constellation of satellites, GPS receivers determine the location of objects with remarkable speed and accuracy, often completing calculations within a second.Advantages of Modern GPS TechnologyContemporary GPS receivers are designed to meet the practical demands of field...
333
Types of Global Positioning System Surveys
378
GPS surveying methods vary in application, accuracy, and data collection techniques, catering to diverse surveying and mapping needs. Static GPS, kinematic GPS, and real-time kinematic (RTK) surveying are widely used. Each technique offers distinct advantages.Static GPS involves placing one receiver at a known reference point and another at the target point. It collects exact positional data by observing multiple satellite ranges over an extended period, achieving centimeter-level accuracy for...
378

