Assessment of ichthyofauna bycatch of the sea-bob shrimp fishery from the municipality of Pontal do Paraná, Paraná coast, Brazil

Abstract

This study aimed to assess the composition of ichthyofauna bycatch from artisanal shrimp trawls used in the shallow inner continental shelf in front of the municipality of Pontal do Paraná, on the Paraná coast. Bycatch can be defined as the catch of non-target species. Nearly all fishing methods are characterized by at least some bycatch, although trawling is among the most problematic. In partnership with the fishermen of Barrancos beach, 12 hauls per month were surveyed between July 2008 and April 2009. The total catch was 1,083 kg and comprised fish (327.09 kg) and shrimp (576.21 kg), with a shrimp-to-fish ratio of 1:0.57. Regarding the ichthyofauna bycatch, a total of 26,743 fish were caught, comprising 27 families and 68 species, of which only tree belonged to the class Chondrichthyes. The families with the greatest species richness were Sciaenidae (18), Carangidae (6), Ariidae (5), and Achiridae, Engraulidae and Paralichthyidae (4). The families Sciaenidae and Carangidae accounted for 80% of the total catch. The species Stellifer rastrifer, Selene setapinnis, S. brasiliensis, Larimus breviceps, Paralonchurus brasiliensis and Cathorops spixii were dominant, representing 80% of the total catch. Further, of these species, S. setapinnis and S. rastrifer accounted for 44% of the total catch in number of individuals. Temporal significant differences were observed for abundance, number of species, diversity and equitability. It is concluded that the fish fauna of the bycatch of the inner shelf shallow coast of Paraná is dominated by demersal species, mostly belonging to the Sciaenidae.