Benchmark Workshop for Barents Sea and Faroese Stocks (WKBARFAR 2021)
WKBARFAR 2021 met online to revise the advice basis of three stocks: Northeast Arctic (NEA) cod, Norwegian coastal cod north of 62 degrees, and Faroese ling. During the course of the meeting,it was decided to split the Norwegian coastal cod into two separate stocks: a data-rich stocknorth of 67 degrees north, and a data-poor stock between 62 and 67 degrees north. The NEA codreceived a revision to the existing Category 1 SAM (State-space Assessment Model) model, Norwegian coastal cod south will receive advice based on the “3-over-2” rule, while both Norwegiancoastal cod north and Faroese ling move from Category 3 to Category 1 stocks with SAM assessments.
NEA cod: A revised version of the Category 1 SAM assessment was approved for the advicebasis for NEA cod. Given the use of density-dependence in estimating reference points, thebenchmark was not able to revise these estimates. Tests were conducted indicating the biomasslimit (Blim) remained appropriate, that the existing Harvest Control Rule (HCR) remained precautionary,and that the performance of the HCR is not expected to be substantially impacted bythe revision in the assessment model. Reference points will be fully re-evaluated at a forthcomingHCR evaluation, likely in 2022.
Faroese ling: This stock will now be assessed with a Category 1 SAM model, previously the stock was Category 3 with no analytic assessment. Full reference points are estimated, althoughthe actual management is currently based on days at sea controls.
Norwegian coastal cod north of 67°N: Category 1 SAM model, the first accepted analytic assessmentfor this stock. Evaluation of the Spawning–stock biomass (SSB) to recruit plot indicated acontinued increase in recruitment across the range of SSBs observed during the model period.Consequently, Blim is provisionally set to the highest observed SSB, with a strong recommendationto conduct further investigations and put in place a recovery plan for this stock. Withoutevidence of recruitment performance above Blim, no reliable estimates could be provided for Freference points.
Norwegian coastal cod between 62 and 67°N: Advice for this stock will be using Category 3,with a “3-over-2” rule based on the Catch Per Unit of Effort (CPUE) index from the referencefleet, with a Length-Based Spawners Per Recruit (LBSPR) model used to indicate if a precautionarybuffer is required. It is likely that a SPiCT (Production model in Continuous Time) modelmay be a viable future assessment method, once the reference fleet CPUE time-series has beenextended sufficiently.
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