An independent review of the Assessment of the walleye pollock stock in the Eastern Bering Sea
This is an independent review of the assessment of walleye pollock in the Eastern Bering Sea. The following bullet points summarize the findings of this review. • This review focuses on the methods that were used to obtain the reference points that are used to define the harvest control rule, and is...
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| Format: | Text |
| Language: | English |
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2009
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| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.543.1044 http://www.seafoodnews.com/news/images/gppollockreview.pdf |
| Summary: | This is an independent review of the assessment of walleye pollock in the Eastern Bering Sea. The following bullet points summarize the findings of this review. • This review focuses on the methods that were used to obtain the reference points that are used to define the harvest control rule, and is not a critic of the harvest control rule or management objectives for this fishery. • The tier 1b harvest control rule requires estimates of FMSY, BMSY (reference points), and projections of spawning stock biomass and vulnerable biomass, as well as associated mea-sures of uncertainty. There are ample data available to estimate these reference points; however, a large number of assumptions are required to make use of these data. • This years assessment model has changed considerably over last years assessment in that 100s of additional parameters have been added to the model, the prior distribution for steep-ness has changed, and the sample sizes for the age-composition data have been down weighted. All of these changes are likely to increase statistical uncertainty and increase estimates of the optimal fishing mortality rate (FMSY). • Despite the increase in model complexity (as measured by the number of estimated pa- |
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