2018 Assessment of the Northern Rockfish Stock in the Bering Sea and Aleutian Islands
In 2005, Bering Sea/Aleutian Islands (BSAI) rockfish were moved to a biennial assessment schedule with full assessments in even years to coincide with the frequency of trawl surveys in the Aleutian Islands (AI) and the eastern Bering Sea (EBS) slope. In 2017, the scheduled frequency for some stock assessments was changed in response to the National Stock Assessment Prioritization effort. Bering Sea/Aleutian Islands (BSAI) northern rockfish will maintain a biennial schedule but with full assessments in odd years, with the next full assessment scheduled for 2019. In years without a full assessment, a “partial assessment” is produced by revising the recent catch data and re-running the projection model using the results from the previous full assessment as a starting point. Therefore, this update does not incorporate any changes to the 2016 assessment methodology but does update the catches for 2016-2018 and provides estimated catches for 2019-2020. The partial assessment also includes estimates of catch/biomass (i.e., exploitation rates), using estimated total biomass.
Changes in input data: The updated information for this partial assessment is replacing the estimated 2017 catch with the final catch value and revising the 2018 and 2019 catch estimates. The 2017 catch was 4,699 t, 6% smaller than the estimate of 5,000 t that was used in the 2017 projection. The 2018 catch is projected to be 5,959 t, 22% larger that the estimate of 4,895 in the 2017 projection. The estimated 2019 and 2020 catches are assumed to result from fishing at the estimated 2018 F, resulting in 5,808 t and 5,684 t, respectively.