SUMMARY

The catch per unit of effort (CPUE) is affected by abundance, but also by environmental variables and by the fishermen strategy. Abundance aside, the CPUE is related to factors that change the vulnerability of the stock. If estimates of the effects of these factors are available, they could be used to forecast favorable fishing sites. We analyzed CPUE of skipjack (Katsuwonus pelamis) caught by pole-and-line fleet in the southwest Atlantic to find favorable fishing scenes. We used generalized linear models (GLM) and the logbooks reports of 1994. Factors alone and interactions among them were used as explanatory variables, while we assumed the CPUE to have a lognormal distribution. The Akaike Information Criterion (AIC) and the deviance were used to select the relevant factors. Main effects of “quarters ” and “area ” were the most relevant, but there were also some important interactions. Usually fishing operations in the second quarter and in the south area carried out concomitant with clean sky and weak winds result in the largest values of CPUE. This is the more profitable scene for fishing skipjack tuna in the southwest Atlantic with pole-and-line. RÉSUMÉ La capture par unité d’effort (CPUE) est affectée par l’abondance, mais également par de