Analysis of the "mistura†category in the pair trawl fishery landed in Santos and Guarujá, São Paulo, Brasil

Abstract

The so-called mistura category is very important in the São Paulo State fishery production, mainly in the pair trawl fishery landings. It is composed of a great number of low value commercial species and small individuals of the commercial importance species. The samples were obtained from pair trawl fleet from June 2001 to May 2002, and a total of 58 species were identified. The analysis of the Index of Relative Importance stands out the presence of the family Sciaenidae (%IRI=79.6) and of the species white mouth croaker, Micropogonias furnieri (%IRI=43.7), southern king croaker, Menticirrhus americanus (%IRI=34), and American harvest fish, Peprilus paru (%IRI=8.6). Whitemouth croaker and southern king croaker were more important during summer/autumn and winter/spring, respectively. The relationship between the capture of each species as "mistura†and its pair trawl fleet total catch landed in Santos and Guarujá along the study period was evaluated. Considering as components of the "mistura†the white mouth croaker and southern king croaker catch increased 13.2% and 26% respectively. In the case of white mouth croaker, the presence of individuals below the medium length of first maturity was estimated in 201 tons. The high occurrence of commercial importance species made the "mistura†a significant category for pair trawl fishery management, not only by the amount of the small individuals, but also due to the presence of individuals below mean length of first maturity. The lack of "mistura†composition assessment could create erroneous evaluation in the fisheries production statistics, due to a highest fishery pressure then that actually verified for these species, especially those of commercial importance.