2018 Assessment of the Shark Stock Complex in the Gulf of Alaska

January 30, 2019

The shark complex (spiny dogfish, Pacific sleeper shark, salmon shark and other/unidentified sharks) in the Gulf of Alaska (GOA) is regularly assessed on a biennial stock assessment schedule. The 2017 assessment was delayed until 2018 to coincide with the Bering Sea Aleutian Islands (BSAI) shark stock complex assessment and in future years both assessments will be done in even years. GOA sharks have been a Tier 6 complex, but, the acceptable biological catch (ABC) and overfishing level (OFL) for spiny
dogfish are calculated using a Tier 5 approach (termed Tier 6*) with the survey biomass estimates, as estimated with a random effects model, considered a minimum estimate of biomass. In this assessment the authors propose a new spiny dogfish model (Model 15.3A), which accounts for the proportion of the population not accessible to the survey, and thus moving the spiny dogfish to Tier 5. The total OFL for the GOA shark complex is the sum of the Tier 5 (spiny dogfish) and Tier 6 (all other sharks)
recommendations. Recommendations are determined by average historical catches between the years 1997–2007 for the Tier 6 GOA sharks. For this summary, we have updated the time series of catch through October 9, 2018 to reflect any changes that might have occurred in the Catch Accounting System (for the years 2003–2018).