2013 Assessment of the Rockfish Stock Complex in the Gulf of the Alaska

The demersal shelf rockfish assemblage (yelloweye, quillback, copper, rosethorn, canary, China, and tiger rockfish) is assessed on a biennial cycle, with full stock assessments conducted in odd calendar years to coincide with new survey data. This year, although an odd year, we present an executive summary as we develop a statistical age-structured model for 2014. In addition, we are transitioning from a submersible to a remote operated vehicle as our visual survey vehicle. The future age-structured model will incorporate submersible, remote operated vehicle density estimates, commercial, sport, and subsistence fishery data, and International Pacific Halibut Commission survey data.

In this stock assessment document, we present two options. The first option is based on our historical methodology of using the most recent survey derived yelloweye rockfish density estimates for each management area in the Southeast Outside to calculate the total available DSR biomass. The second option was developed based on the September 2013 Plan Team discussion regarding the risk in continuing to roll forward the most recent year of survey data from each management area, rather than using a model-based approach to incorporate interannual variability. At the Plan Team’s recommendation, we present this second option: a random walk time series model estimate of biomass in which process errors are estimated as a random effects approach.