Western Pacific Stock Assessment Review of the 2023 Stock Assessment Update for Deep-7 Bottomfish in the Main Hawaiian Islands

Scientists from the Pacific Islands Fisheries Science Center conducted a benchmark stock assessment of the main Hawaiian Islands Deep 7 bottomfish complex. Since this is a benchmark assessment, many improvements were incorporated and all assessment components were reevaluated. Most of the improvements incorporated were recommended by the Western Pacific Stock Assessment Review (WPSAR) panel evaluations of the 2018 and 2021 assessments and others were implemented to follow current best practices for conducting stock assessments. 

This benchmark assessment incorporated the time-series data for the fishery-independent survey as an index of relative abundance that was standardized using a spatio-temporal modeling framework. The assessment used a state-space Bayesian surplus production model within the Just Another Bayesian Biomass Assessment (JABBA) modeling framework. 

This assessment used commercial data for the years 1948-2023 and assessed Deep 7 bottomfish by building on the framework from the previous four assessments, but with improved data filtering, along with improvements to commercial catch-per-unit-effort (CPUE) standardization and incorporation of unreported catch. The assessment includes unreported catches using methods similar to those applied in previous assessments but with corrections to previous calculations and the inclusion of the most recent non-commercial catch estimates from the Marine Recreational Information Program. Changes to the inclusion of the unreported catches and the time series of fishery-independent survey estimates were made in collaboration and partnership with the bottomfish fishing community through a series of fisher engagement workshops. There were three workshops held in preparation for the WPSAR review.

NOAA Fisheries and the Western Pacific Fishery Management Council announced the review of the 2023 Benchmark Stock Assessment for the Main Hawaiian Islands Deep 7 Bottomfish Complex in the Federal Register on November 20, 2023.