TY - BOOK
T1 - Benchmark Workshop for Barents Sea and Faroese Stocks (WKBARFAR 2021)
AU - Ofstad, Lise Helen
AU - Steingrund, Petur
A2 - Howell, Daniel
PY - 2021
Y1 - 2021
N2 - 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 stock north of 67 degrees north, and a data-poor stock between 62 and 67 degrees north. The NEA cod received 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 Norwegian coastal 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 advice basis for NEA cod. Given the use of density-dependence in estimating reference points, the benchmark was not able to revise these estimates. Tests were conducted indicating the biomass limit (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 by the revision in the assessment model. Reference points will be fully re-evaluated at a forthcoming HCR 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, although the 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 assessment for this stock. Evaluation of the Spawning–stock biomass (SSB) to recruit plot indicated a continued 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 recommendation to conduct further investigations and put in place a recovery plan for this stock. Without evidence of recruitment performance above Blim, no reliable estimates could be provided for F reference 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 reference fleet, with a Length-Based Spawners Per Recruit (LBSPR) model used to indicate if a precautionary buffer is required. It is likely that a SPiCT (Production model in Continuous Time) model may be a viable future assessment method, once the reference fleet CPUE time-series has been extended sufficiently.
AB - 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 stock north of 67 degrees north, and a data-poor stock between 62 and 67 degrees north. The NEA cod received 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 Norwegian coastal 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 advice basis for NEA cod. Given the use of density-dependence in estimating reference points, the benchmark was not able to revise these estimates. Tests were conducted indicating the biomass limit (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 by the revision in the assessment model. Reference points will be fully re-evaluated at a forthcoming HCR 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, although the 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 assessment for this stock. Evaluation of the Spawning–stock biomass (SSB) to recruit plot indicated a continued 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 recommendation to conduct further investigations and put in place a recovery plan for this stock. Without evidence of recruitment performance above Blim, no reliable estimates could be provided for F reference 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 reference fleet, with a Length-Based Spawners Per Recruit (LBSPR) model used to indicate if a precautionary buffer is required. It is likely that a SPiCT (Production model in Continuous Time) model may be a viable future assessment method, once the reference fleet CPUE time-series has been extended sufficiently.
KW - Northeast Arctic (NEA) cod
KW - Faroese ling
KW - Norwegian coastal cod north of 62 degrees
UR - https://ices-library.figshare.com/articles/_/18619163
U2 - 10.17895/ices.pub.7920
DO - 10.17895/ices.pub.7920
M3 - Commissioned report
T3 - ICES Scientific Reports
BT - Benchmark Workshop for Barents Sea and Faroese Stocks (WKBARFAR 2021)
PB - ICES
CY - Copenhagen, Denmark
ER -