2018 Assessment of the Deepwater Flatfish Stock Complex in the Gulf of Alaska
The Gulf of Alaska deepwater flatfish complex (consisting of Dover sole, Greenland turbot, and deepsea sole) is assessed every four years and was last assessed in 2015. In years without an assessment, we present an executive summary to recommend harvest levels for the next two years. Please refer to the 2015 full stock assessment report for further information regarding the assessment model (McGilliard and Palsson, 2015. A full stock assessment document with updated assessment and projection model results will be presented in 2019.
Dover sole is assessed using an age-structured model and Tier 3 determination. Thus, the single species projection model was run using parameter values from the accepted 2015 Dover sole assessment model (McGilliard and Palsson 2015), together with updated catch information for 2017-2020, to predict stock status for Dover sole in 2019 and 2020 and to make ABC recommendations for those years. Projections are conducted using numbers-at-age for Dover sole from age 3-59+ and historical recruitment of age 3 individuals to calculate OFL’s and ABC’s. Greenland turbot and deepsea sole fall under Tier 6. ABC’s
and OFL’s for Tier 6 species are based on historical catch levels (average catch over the years 1978-1995) and therefore these quantities cannot be updated. ABC’s and OFL’s for the individual species in the deepwater flatfish complex are determined only as an intermediate step for the purpose of calculating complex-level OFL’s and ABC’s.