2014 Assessment of the Rougheye and Blackspotted Rockfish Stock Complex in the Gulf of Alaska
Rockfish are assessed on a biennial stock assessment schedule to coincide with the availability of new survey data.
We use a statistical age-structured model as the primary assessment tool for Gulf of Alaska rougheye and blackspotted rockfish which qualifies as a Tier 3 stock. This assessment consists of a population model, which uses survey and fishery data to generate a historical time series of population estimates, and a projection model, which uses results from the population model to predict future population estimates and recommended harvest levels.
The data sets used in this assessment include total catch biomass, fishery age and size compositions, trawl and longline survey abundance estimates, trawl survey age compositions, and longline survey size compositions. For this assessment year, there are three models presented in the assessment. Model 0 is the last full assessment base model from 2011. Model 1 is an intermediate model which uses all the new and updated data but keeps the previous longline survey abundance index based on weights and the old conversion matrices. Finally, Model 2 is the author preferred model which uses all the new and updated data, the longline survey abundance index based on numbers, and the updated conversion matrices.