Evaluating the Mechanisms Underlying Distribution Shifts and Age-Truncation in Silver Hake (Merluccius bilinearis) Survey Data

We propose a life-stage specific analysis of the mechanisms underlying shifts in the distribution of silver hake. Previous work has clearly documented a shift in the center of biomass of silver hake sampled on the northeast shelf during the spring trawl survey. The principal goal of our project is to evaluate whether this shift is consistent across life stages ( larvae, juveniles, adults) and between summer spawning and the winter southerly migration. This will be accomplished by intergrating analyses of larval and adult silver hake distribution and movement in order to evaluate, not just the shifts in silver hake, but also the seeming contradictions in the available adult/juvenil data and stock structure data that continue to cause problems for age-structured assessments.