2015 Assessment of the Yellowfin Sole Stock in the Bering Sea and Aleutian Islands
February 12, 2015
Changes were made to the weight-at-age empirical data where values from ages 11 to 20 were smoothed. The assessment updates last year’s with results and management quantities that are moderately lower than the 2014 assessment. Yellowfin sole continue to be well-above BMSY and the annual harvest remains below the ABC level. The female spawning stock is in a slow downward trend.
Projections are based on estimated catches of 150,000 t used in place of maximum ABC for 2016 and 2017.
For the issues related to weight-at-age, the empirical weight-at-age data from annual shelf survey sampling (Model 1) are not considered perfect but rather reliable empirical estimates to be used in stock assessment modeling. In response to these comments, we closely re-examined the growth model code and the model description and equations in the text. One coding error was found and fixed and we also noticed an age subscript (j) for Model 2 in the text that needed to be omitted. This extra subscript in the Model 2 equation would allow for more parameters being estimated than data, which was not the intent. Also corrected the text to describe Epsilon as an error term for year-effect only (and not age-effect). Thus Model 2 can now correctly be described as the growth increments from Model 0 multiplied by random year effects, and Model 3 as the growth increments from Model 0 multiplied by random year and temperature dependent year effects.