Modeling of the Pacific sardine Sardinops caeruleus fishery of the Gulf of California, Mexico

We used a stochastic age-structured model with density-dependent recruitment to study the fishery and population dynamics of the Gulf of California Pacific sardine (Sardinops caeruleus) stock for the period 1972-1973 to 1989-1990. To determine the value of fishing mortality (F) which corresponds to the long-term optimum yield and cost-benefit ratio (C/B), we simulated fished population trajectories over a period of 50 years. Our results indicated a good fit between observed and predicted annual recruitment and catch. Quasiperiodic oscillations of a five year periodicity for an unfished population faded with increasing F. Maximum yield and C/B were obtained with F=0.475 and 0.275, and the simulated population began declining with F≥0.5 and ≥0.3, respectively. It is proposed that F<0.25 would be adequate for this fishery.