Stock Assessment of American Samoa Bottomfishes, 2023

The Western Pacific Regional Fishery Management Council’s fishery ecosystem plan for American Samoa includes 11 bottomfish management unit species (BMUS) that have traditionally been assessed and managed as a group (i.e., a species complex). The 11 species in the BMUS complex are Aphareus rutilans, Aprion virescens, Caranx lugubris, Etelis carbunculus, Etelis coruscans, Lethrinus rubrioperculatus, Lutjanus kasmira, Pristipomoides filamentosus, Pristipomoides flavipinnis, Pristipomoides zonatus, and Variola louti. These species are targeted by a small yet valuable boat-based fishery in depths ranging around 100 m to 400 m. The previous 2019 assessment concluded this complex was both undergoing overfishing and was overfished.

The current benchmark assessment for the American Samoa BMUS differs significantly from all previous efforts in terms of data inputs and model structure. A major improvement for this new benchmark was the move to single-species, age-structured models in the Stock Synthesis modeling framework for all BMUS except E. carbunculus and P. filamentosus (Methot and Wetzel 2013). Stock Synthesis 3.30 is an integrated statistical catch-at-age model that fits a population model to relative abundance and size composition data in a likelihood-based statistical framework to generate maximum likelihood estimates of population parameters, derived outputs, and their associated variability. These outputs are then used to determine stock status and to develop stock projections under different management scenarios

The Pacific Islands Fisheries Science Center of NOAA’s National Marine Fisheries Service uses the NOAA Technical Memorandum NMFS-PIFSC series to disseminate scientific and technical information that has been scientifically reviewed and edited. Documents within this series reflect sound professional work and may be referenced in the formal scientific and technical literature.

Nadon MO, Oshima MC, Bohaboy EC, Carvalho F. 2023. Stock assessment of American Samoa bottomfishes, 2023. U.S. Dept. of Commerce, NOAA Technical Memorandum NOAA-TM-NMFS-PIFSC-143, 239 p.  https://doi.org//10.25923/0sd4-9a69.