...
  • 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 >Auxiliary and focal assessment models: a proof-of-concept involving time-varying catchability and fishery stock-status evaluation
【24h】

Auxiliary and focal assessment models: a proof-of-concept involving time-varying catchability and fishery stock-status evaluation

机译：辅助和重点评估模型：涉及时变捕捞能力和渔业种群状况评估的概念验证

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

Many assessment models evaluate stock status, and biases can arise when time-varying processes are modelled as being time-invariant. An "auxiliary/focal" assessment process is presented, where an "auxiliary" assessment model estimates functional parameters that are used in a "focal" assessment of stock status. This process is evaluated in two steps. First, estimates of density-dependent catchability from single- or multispecies auxiliary models are compared, confirming that multispecies auxiliary models are more accurate when catch-at-age data are abundant. Possible output from the multispecies auxiliary assessment is then used in a focal model, and the results are compared with four other methods: (i) assuming that catchability is constant, (ii) ignoring fishery-dependent indices, (iii) a random-walk catchability model, and (iv) estimating density-dependent catchability without prior information. Results show that the constant catchability model leads to non-conservative biases in stock-status estimates, and a random-walk model decreases bias and has high precision when age data are available. The auxiliary/focal procedure performs best when fishery indices are used without age data, and the density-dependent model without prior information performs well with fishery and survey indices, but without age data. Different methods are optimal, therefore, depending on data availability, and the auxiliary/focal assessment process performs best of the available methods when using just fishery-dependent indices.
机译：许多评估模型都评估库存状态，并且当将时变过程建模为时不变时，可能会产生偏差。提出了“辅助/重点”评估过程，其中“辅助”评估模型估计在库存状态的“重点”评估中使用的功能参数。此过程分两个步骤进行评估。首先，比较了单物种或多物种辅助模型中与密度有关的捕捞能力的估计值，从而证实了当捕捞年龄数据丰富时，多物种辅助模型更为准确。然后将多物种辅助评估的可能输出用于焦点模型，并将结果与​​其他四种方法进行比较：（i）假设捕捞能力是恒定的；（ii）忽略依赖渔业的指数；（iii）随机游走可捕获性模型，以及（iv）在没有先验信息的情况下估计密度相关的可捕获性。结果表明，恒定的可捕获性模型会导致库存状态估计中出现非保守偏差，而随机游走模型则可以减少偏差并在可获得年龄数据时具有较高的精度。当使用没有年龄数据的渔业指数时，辅助/焦点程序的效果最佳；而没有先验信息的密度相关模型在没有年龄数据的情况下，具有渔业和调查指数的效果很好。因此，取决于数据的可用性，不同的方法是最佳的，并且仅使用与渔业相关的指标时，辅助/焦点评估过程会执行可用方法中的最佳方法。

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