Species composition and assemblage analysis of fishes caught as bycatch by the Patagonian shrimp fishery in the southwest Atlantic

Abstract

Bottom trawl fishing is the most used worldwide gear generating large amountsof discards due to bycatch of a variety of species. Shrimp fisheries are recognized fortheir high incidence in global discards. In waters of Patagonia Argentina (43°S - 47°S)an industrial shrimp fishery of high economic value is developed whose target speciesis the Patagonian shrimp Pleoticus muelleri. The information presented in this studycomprises a period of 12 years (2003-2014) and it was gathered by the On-board ObserverProgram. The Program collects information of all species captured in the fishing fleets.The data analyzed corresponds to the double-rigged otter trawler fleet and the coastalfleet. The fish bycatch composition was characterized in both fleets and the frequenciesof occurrence of species and the assemblage areas were analyzed. A total of 101 fishspecies were identified (59 families) of which 69 were bony fishes, 29 cartilaginous fishesand three species of jawless fishes. The assemblages described correspond to coastaland deep waters, and they are integrated by temperate and subtropical species pointingout the area as an ecotonal zone.