Roughhead Grenadier subarea 2 and 3 XSA model configuration

Abstract

STACFIS recommended in 2007 to explore the eXtended Survivors Analysis (XSA) configuration of the analytical assessment presented (definition of the plus group, catchability model and the shrinkage options), as well as the incorporation of the new survey information into the model. This document tries to respond this recommendation with the following suggestions. To establish the plus group in 17+ because the percentage of maturity (93%) as well as the percentage in biomass (10%) and abundance (2%) would be reasonably and the stability of the model would improve appreciably compare with the 19+ plus group used in the 2007 XSA. To define the Fbar age range between 6 and 13 years because this range is representative of the most important ages in the catches and avoid most of the problems of the partial recruitment and the plus group assumptions. To consider all ages with catchability independent of the year class strength and to use a mean model to determine the relationship between the log CPUE and the Log VPA abundance and setup q constant for ages older than 15 years. To use the last two ages (14-15) and the last two years (2005-2006) as range for the shrinkage with a standard error of 1.0 for the F shrinkage means