A PRELIMINARY COMPARATIVE ANALYSES ON THE SKIPJACK TUNA (Katswonus pelamis) CATCH EFFICIENCY OF PURSE SEINE AND BAIT BOAT FLEETS

Abstract

The fishing of skipjack tuna (Katsuwonus pelamis) in Brazil is almost completely carried out by baitboat fleet. A very small part is done by purse-seine vessels that normally have sardines as a target, but during the annual sardine moratorium, they turn their fishing activities to skipjack tuna. Following the tendencies of the fishing activities realized in the West Atlantic and Caribbean, fisheries in Brazil have shown an interest in the substitution of baitboat by purse-seine vessels, aiming at an increase in the production of skipjack tuna and a reduction of the problem of capturing small fish (bait). In this work a preliminary comparison between the efficiency of the two fishing techniques was carried out, using the fishing power and the length frequency distribution of the specimens captured. The objective was to supply relevant information to that the political substitution of fleets are not being deflagrates without the necessary knowledge. In spite of the purse-seine vessels are not technologically adapted for the fishing of tuna, it can be verified that comparatively each one of them has the fishing power up to three times greater than those baitboat vessels. The length frequency distribution obtained by the fisheries using both types of boat were very similar, demonstrating that there maybe no significant differences in the selectivity of both gears.