Modeling somatic and otolith growth of the central subpopulation of northern anchovy (Engraulis mordax) by incorporating seasonality

Abstract

— Somatic growth parameters are used in age-structured stock assessment models, such as those used to assess the federally managed northern anchovy ( Engraulis mordax ); therefore, incorrect estimation of growth can cause errors that affect estimates from stock assessments. To our knowledge, we completed the first comprehensive investigation to model somatic and otolith growth of the central subpopulation of northern anchovy (CSNA), which has a range from Northern California to Baja California, Mexico, by using fishery-dependent and fishery-independent data. Five growth models were fitted to length- at-age data, including 2 models that account for seasonal growth oscillations, to determine the model that best described growth. Seasonal growth oscillations were found for the CSNA