Annual report: 2019 fall bottomfish fishery-independent survey in Hawaiʻi

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 2019 BFISH survey comprised 517 primary sampling units (PSU) across the eight main Hawaiian Islands. Two survey sampling gears, cooperative research hook-and-line fishing and stereo camera systems, were deployed at depths ranging from 75 to 400 m from September 14 to November 26, 2019. In the 2019 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 and ehu were the two main design species. The estimated stock biomass of ʻōpakapaka and onaga was approximately 1.563 and 0.537 million kg, respectively. Ehu stock biomass was about 1.067 million kg. Coefficients of variation (CV%) for exploited stock biomass for ehu and ʻōpakapaka were 17.54 to 23.04, respectively, and were improved over the previous survey year. To improve overall precision of BFISH surveys, future research will focus on (1) refining PSU metrics of habitat complexity (e.g., bottom hardness, rugosity, etc.); (2) target sample allocations to better reflect species’ depth preferences; and, (3) investments in technological innovations that better define the unit area sampled. 2020 NMFS (National Marine Fisheries Service) PIFSC (Pacific Islands Fisheries Science Center) Submitted https://doi.org/10.25923/vnnb-t036 Public Domain 1863