2014 Assessment of the Pacific Ocean Perch Stock in the Gulf of Alaska
April 09, 2014
Rockfish are assessed on a biennial stock assessment schedule to coincide with the availability of new survey data. For Gulf of Alaska rockfish in on-cycle (odd) years, we present a full stock assessment document with updated assessment and projection model results
Due to the 2013 government shutdown we did not present alternative model configurations in the 2013 assessment. As requested, we are providing a full assessment in 2014 in order to present an alternative model that incorporates new maturity information.
We use a statistical age-structured model as the primary assessment tool for Gulf of Alaska Pacific ocean perch 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. For this year, we update the 2013 assessment model estimates with new data collected since the last full assessment.
For the 2015 fishery, we recommend the maximum allowable ABC of 21,012 t from the updated model. This ABC is a 9% increase from the 2014 ABC of 19,309 t. The increase is attributed to updating weight-at-age and the size-age transition matrix as well as incorporating new maturity information that decreases the age at 50% maturity. This also resulted in a 6% higher ABC than the 2015 ABC projected last year. The corresponding reference values for Pacific ocean perch are summarized in the following table, with the recommended ABC and OFL values in bold. Overfishing is not occurring, the stock is not overfished, and it is not approaching an overfished condition.