Aspects of the biology and fishing of the Brazilian mackerel, Scomberomus brasiliensis, caught with gilnet in Northeastern Brazil

Abstract

The present paper adresses biological and fishing aspects of the Brazilian mackerel, Scomberomorus brasiliensis, an outstanding artisanal resource in Northeastern Brazil, concerning fishing technology, by-catch and biometric ratios that affesct the enmeshing process. The study material was obtained through sampling of 482 catch landings performed along the northeastern coats in the years 1998 to 2001, and 19 experimental fishing cruises using an arroy of nets with 70,80,90,100 mm meshes. The specific composition of the gill net catch presents spaces and time variations in the Northeastern region, but Brazilian mackrerel is the main target as it is the most important species in terms of fishing yield in most states and time of the year. The most commonly found species as by-catch in the gillnet fishery have a body similar in shape to that of Brazilian mackerel. This is the case with king mackerel, Scomberomorus cavalla, but not with blue runner, Caranx crysos, and Atlantic thread-herring, Opisthonema oglinum, whose bodies are relatively taller. The catching os those three species is mainly accomplished by enmeshing in the body area between the first dorsal fin and the anal fin, which corresponds with the fish’s maximum girth.