An independent review of the Assessment of the walleye pollock stock in the Eastern Bering Sea

• Main Author: Steven Martell
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 2009
• Subjects: Bering Sea
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.543.1044; http://www.seafoodnews.com/news/images/gppollockreview.pdf

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-