Análise das espécies de tubarões capturadas por espinhel pelágico de superfície com lançamento diurno e noturno no período de 2004 a 2011

Abstract

Pelagic longline fishing has been present complementing Brazilian economy since the 1950's and has become increasingly established. Although it is considered selective, this modality of fishing reaches both target and non-target species. The main species incidentally caught by longlines are seabirds, marine mammals, turtles and sharks. Considering the vulnerability of sharks, as well as their ecological importance for marine ecosystems this present work aimed to analyse whether there are differences in catches number for diurnal and nocturnal releases in pelagic longline fisheries. The analyses were performed using a database and from these CPUE and EFFORT calculations were made. The results obtained showed that nocturnal launches are more efficient in capturing target and non-target species. In addition to the higher number of catches of species such as Xiphias gladius, Thunnus alalunga and Thunnus obesus, which species of great economic return, catches of vulnerable, threatened and critically endangered species are also observed whose makes this fishing technique even more harmful to marine ecosystems and fragile niches. We conclude that nocturnal launches are an alternative to increase fisheries production in face to increasingly scarce resources the environmental impact generated by these habits may be even more significant than the possible economic returns.