Review of stock assessment and fishery biology of Dosidicus gigas in the Gulf of California, Mexico

Two periods in the Dosidicus gigas fishery in the Gulf of California, Mexic o, have been examined. The first was in the early 1980s, when there was a s ingle stock with multiple cohorts and recruitment to the principal fishing grounds was in May. Management schemes were difficult to establish because of the variation in the annual abundance of the cohorts. During 1983, the f ishery collapsed; an effect of El Nino was an acceptable hypothesis. The se cond period began in 1994. Landings increased from 1994 to 1996. During thi s time there was only one annual cohort in the fishery with recruitment in May. A management strategy was proposed adopting the stock assessment used for Illex argentinus in the Falkland Islands; assuming an annual recruitmen t, an estimate of the proportional escapement and modelling the catch-per-u nit-effort data of the three commercial fleets. Using this approach, the la ndings in 1997 were 120 000 t. However, in 1998 a decrease in landings occu rred, a possible cause could have been the 1998 El Nino. Some aspects of th ese two periods are discussed, principally showing the differences in the m anagement approach. (C) 2001 Elsevier Science B.V. All rights reserved.