Integrated assessment model for the north-central stock of Peruvian anchoveta Engraulis ringens Jenyns

Abstract

 A new integrated assessment model for the northern-central stock of Peruvian anchovy is presented, which allows the reconstruction and follow-up of the length structure of the stock using an underlying age structured model. The model was calibrated using acoustic estimates of biomass and length structure from scientific surveys and from the fishery landings. An evolutionary algorithm with different fitness functions for each variable was used for the calibration (biomass and yield). Monthly estimates of total biomass, spawning stock biomass and recruitment given by the model for 1964-2008 are presented. Three different periods in anchovy dynamics were recognized, between 1961-1971, 1971-1991 and 1991 to the present, with distinguishable mean annual biomasses and recruitment values.