Impacto do sistema pesqueiro multifrota sobre o estoque do peixe-porco (Balistes capriscus) capturado no Estado de São Paulo

Abstract

The gray triggerfish (Balistes capriscus) is an important fisheries resource in São Paulo State, southeastern Brazil. In this study, fisheries production and length distribution data per fleet were analyzed to assess the impact of a multi-fleet fishery system on its stock. The analysis was based on data taken from double rig otter trawl, purse seine and pair-trawl fleets, from April 1997 to December 2000. The effectiveness of fisheries regulation strategies and life history traits were also considered. Target effort analysis showed that gray triggerfish was a by-catch for most fishing fleets. The total mortality rate (Z), calculated considering the total catch, was 1.04 ± 0.3 year-1 . Selectivity curves indicated the lowest length of first capture for double rig otter trawl (232 mm) and the highest for purse seine (235 mm). Selectivity curves, mortality and exploitation rates suggested that exploitation of gray triggerfish stock should be at a sustainable level. However, considering the scarcity of traditional resources and the ability of fishing fleets in direct their catches, the continued monitoring of the catch and effort data for this species is recommended.