Annual Report: 2020 Fall Bottomfish Fishery-Independent Survey in Hawaiʻi
April 29, 2022
Results of the annual bottomfish fishery-Independent survey in Hawaiʻi (BFISH).
The Bottomfish Fishery-Independent Survey in Hawaiʻi (BFISH) provides robust estimates of size-structured population abundance and biomass for the main Hawaiian Islands Deep-7 bottomfish complex. These survey data complement and enhance the stock assessment process
conducted by the Pacific Islands Fisheries Science Center (PIFSC).
The 2020 BFISH survey comprised 500 primary sampling units (PSUs) across the 8 main Hawaiian Islands. Two sampling gears, cooperative research hook-and-line fishing and stereo camera systems, were deployed at depths ranging from 75 to 400 m from August 15 to
November 15, 2020. In the 2020 BFISH survey, ehu was the most abundant species of the Deep-7 complex, followed by ʻōpakapaka and kalekale. ʻŌpakapaka had the highest estimated exploited stock biomass, followed by ehu and kalekale. ʻŌpakapaka, ehu, and onaga were the three main design species.
The estimated stock biomass of ʻōpakapaka and ehu was approximately 2.335 and 1.945 million lb, respectively. Onaga stock biomass was about 0.739 million lb. Coefficients of variation (CV%) for exploited stock biomass for ehu and ʻōpakapaka were 17.91 to 32.25, respectively.
To improve overall precision of BFISH surveys, future research will focus on the following:
(1) Increase the number of primary sampling units (PSUs) to optimize future sampling efforts with respect to the number of PSUs required to achieve the desired coefficient of variation (CV) for biomass estimates.
(2) Target sample allocations to better reflect species’ depth preferences.
(3) Invest in technological innovations that better define the unit area sampled and which can increase the depth range of the MOUSS camera system.
(4) Develop methods to improve empirical estimates of the effective sampling area of the MOUSS camera system.
Richards BL, Smith SG, Ault JS. 2022. Annual Report: 2020 Fall bottomfish fishery-independent survey in Hawai?i. U.S. Dept. of Commerce, NOAA Technical Memorandum NOAA-TM-NMFS-PIFSC-125, 31 p. https://doi.org/10.25923/mb72-4g30.