...
  • 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 >Influence of improved performance monitoring on the consistency of a bottom trawl survey
【24h】

Influence of improved performance monitoring on the consistency of a bottom trawl survey

机译：改进的性能监控对海底拖网调查一致性的影响

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

Numerous trawl hauls, made during the triennial bottom trawl surveys (1977-1998) conducted by the National Marine Fisheries Service off the U.S. West Coast, had unusually small catch rates of benthic fish and invertebrates (cpue_B), probably because the trawl failed to contact the seabed (off-bottom). Technological advances in the equipment used to monitor trawl performance since 1986 have increased our ability to recognize off-bottom tows, and cpue_B has risen. As direct trawl performance measurements were not available in earlier surveys, a minimum cpue_B derived from the survey with the best monitoring of bottom contact of the time-series (1998) was used as a criterion to eliminate trawls with poor bottom contact from earlier surveys. The truncated data sets produce significantly larger biomass indices, especially in 1980, with increases of 43, 45, and 56% for Dover sole, petrale sole, and Pacific sanddab, respectively. The analysis suggests that changes in cpue_B over the time-series may be related more to changing survey fishing methods than to changes in abundance. Other bottom trawl surveys, which have also added trawl monitoring equipment during their time-series, may have experienced similar changes in trawl performance.
机译：美国西海岸国家海洋渔业局（National Marine Fisheries）在三年一次的底拖网调查（1977-1998）中进行的拖网拖网捕捞数量众多，底栖鱼类和无脊椎动物的捕获率（cpue_B）异常小，可能是因为拖网没有联系海底（底部）。自1986年以来，用于监测拖网性能的设备的技术进步提高了我们识别底拖的能力，而cpue_B也有所提高。由于在较早的调查中没有直接的拖网性能测量结果，因此采用从对时间序列的底部接触进行最佳监视的调查得出的最小cpue_B作为标准，以从较早的调查中消除底部接触不良的拖网。截短的数据集产生的生物量指数明显更大，尤其是在1980年，Dover鞋底，petrale鞋底和Pacific sanddab分别增长了43％，45％和56％。分析表明，时间序列中cpue_B的变化可能与变化的捕鱼方法有关，而不是与丰度变化有关。其他海底拖网调查也已在其时间序列中添加了拖网监控设备，但拖网性能可能发生了类似的变化。

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