...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>ICES Journal of Marine Science >Potential pressure indicators for fishing, and their data requirements
【24h】

Potential pressure indicators for fishing, and their data requirements

机译：捕鱼的潜在压力指标及其数据要求

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Indicators of fishing pressure are necessary to support an ecosystem approach to fisheries management (EAFM). We present a framework that distinguishes four levels of pressure indicators that move from being a simple description of anthropogenic activity to more precisely describing the actual pressure on the ecosystem and its components, but which require increasingly more information to be quantified. We use the example of the Dutch beam trawl fleet in the North Sea to compare these pressure indicators, as the level of information used is increased. The first level is that of fleet capacity (e.g. number of vessels), the second is fishing effort, usually expressed as the number of hours fishing or days at sea, the third incorporates fishing parameters such as the proportion of time actually spent fishing, fishing speed, or gear characteristics, e.g. the size of the beam trawl in order to determine the frequency with which an area is fished, and at the fourth level, the most informative measure of fishing pressure, annual fishing mortality, is available for a few commercial species from stock assessments. For other species, it can be calculated from the lower level pressure indicators through the incorporation of the chance of individuals of a species coming into contact with the fishing gear and the encounter mortality, which is the portion of mortality caused by the passing of the gear. Comparison of trends and absolute values shows that the pressure indicators at different levels differ considerably in their description of both present and historical fishing impact in the North Sea. Therefore, for an EAFM, we advise using the highest level pressure indicator that can be obtained with the data available.
机译：捕捞压力指标对于支持生态系统渔业管理方法（EAFM）是必要的。我们提供了一个框架，该框架区分压力指标的四个级别，这些指标从对人为活动的简单描述变为更精确地描述对生态系统及其组成部分的实际压力，但需要越来越多的信息进行量化。我们使用北海荷兰拖网拖网船队的示例来比较这些压力指标，因为所使用的信息量增加了。第一个级别是船队容量（例如，船只数量），第二个级别是捕捞努力，通常表示为捕捞小时数或海上天数，第三个级别包含捕捞参数，例如实际花费的钓鱼时间，速度或齿轮特性，例如为了确定某个区域的捕捞频率，应使用拖网渔船的大小；在第四级，可以通过种群评估获得一些信息最丰富的捕捞压力度量，即年度捕捞死亡率。对于其他物种，可以通过较低级别的压力指标，通过将某个物种的个体与渔具接触的机会和遭遇的死亡率相结合来计算，这是由于渔具通过而造成的死亡率的一部分。趋势和绝对值的比较表明，不同水平的压力指标在描述北海当前和历史捕捞影响方面有很大不同。因此，对于EAFM，我们建议使用可通过可用数据获得的最高压力指示器。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号