Abstract

Two approaches to address retrospective patterns in stock assessments are compared. The Rose approach is an ensemble of models that all remove the retrospective pattern through changes in data, parameter values, or model assumptions. It is time intensive and can result in a wide range of historical abundance trends. The Rho approach modifies the terminal year estimates of a single model that exhibits a retrospective pattern. It is fast and easy to apply but results in a discontinuous time series. Neither approach identifies the source of the retrospective pattern. The pros and cons of these two approaches are compared in terms of catch advice and stock status using four examples with varying strength and direction of retrospective patterns. The choice of which approach to use could be based on time and expertise available to conduct and maintain an assessment, with Rose preferred if a lot of both are available while Rho preferred otherwise. If the Rho approach is used, managers should consider adjusting their control rule or risk buffer to account for the difference between Rose and Rho results shown here.

中文翻译：

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Rose vs. Rho：比较两种评估股票评估中追溯模式的方法

摘要

比较了两种解决库存评估中追溯模式的方法。Rose方法是一组模型，这些模型都通过更改数据，参数值或模型假设来消除追溯模式。这是时间密集型的，并且可能导致广泛的历史丰度趋势。Rho方法修改了具有回顾性模式的单个模型的最终年度估计。它既快速又易于应用，但会导致时间序列不连续。两种方法都不能确定追溯模式的来源。使用四个示例，这些示例具有不同的回顾性模式和方向，在捕获建议和种群状态方面比较了这两种方法的优缺点。选择哪种方法可以根据进行和维护评估所需的时间和专业知识来决定，如果罗斯和罗斯都有很多选择，则罗斯优先。如果使用Rho方法，管理人员应考虑调整其控制规则或风险缓冲，以解决此处显示的Rose和Rho结果之间的差异。