Uso de dispositivos tecnológicos para a redução da captura de braquiúros pela pesca artesanal de arrasto

Abstract

Bycatch reduction devices (BRD) are technical modifications installed in the codend of trawl nets in order to avoid or to reduce unwanted fishing mortality. We conducted four experiments to assess the BRD performance for brachyurids exclusion small-scale trawl fishery (10-m length canoe, 18HP) from Paraná State coast. We tested two Nordømore grids with different bar spaces (24- mm – G24; 37-mm – G37), a 28-mm square-mesh codend (MQ) and a 28-mm square-mesh codend with a 96-mm upper escape panel (JE). The BRDs were compared against a control net during 60-min paired deployments (total of 6 replicates of each configuration on each season). Nordømore grids retained less total brachyurids (G24: 62%; G37: 53%, p<0,05) than conventional design (control), especially for Callinectes sp., Libinia ferreirae and Arenaeus cibrarius but not significant for Persephona sp. and Hepatus pudibundus. Modified codends (MQ and JE) did not significantly reduce brachyurids (p>0,05). All tested modifications reduced total Xiphopenaeus kroyeri although not significant (G24: 15,77%; G37: 32,08%; J.E: 8,01%; M.Q: 2,41%; p>0,05). Nordømore grids had shown better efficiency for brachyurids. Yet target-species losses must be better understood in order to promote a better dialogue with artisanal fisherman and decision-makers. Thereby, results provided preliminary reference points for an ecosystem approach to trawl fisheries management.