Fauna composition in the longline fi sheries carried out off Northern Brazil as an outcome of the Protuna Project

Abstract

The  fishery of tuna and tuna-like species with longline has shown an outstanding growth over recent years in  Brazil. This research work was carried out in an area corresponding with Amapá, Pará and Maranhão States by means  of experimental  fishing with a drifting longline gear having the same features and dimensions as the one used in  fisheries  off Northeast Brazil. From the analysis of specific catches totalling 4,830  fi sh, the main representative was sword fi sh,  Xiphias gladius , which accounted for 39.32% of the catch, followed by tunas, with 24.35%. The relative abundance of  tunas and sword fish was found to be near the same when measured as CPUE in weight, but it was favorable to sword fish  as CPUE in numbers. The species group named “others” represents 2% of the captured biomass, but when analyzed  as catch in numbers it contributes with 14.62% of the total, outmatching the groups of sharks (14,43%) and bill fishes  (7.29%). Off Northern Brazil, the target species account for 80% of the total catch in weight by drifting longline, follo- wing a similar  fishing pattern to that in the adjoining northeastern region.