Distribution and abundance of chub mackerel, Scomber japonicus Houttuyn, in Rio de Janeiro State, Brazil

Abstract

This paper deals with the catches of chub mackerel, Scomber japonicus Houttuyn, in the Rio de Janeiro State, Brazil, as a by-catch of the Brazilian sardinella, Sardinella brasiliensis, in the years 1993 – 1997. The chub mackerel fishery has a relatively higher importance in the months from March to August, with the highest catches ocurring in the autumn (about 50% of the year production). The fishery productivity decreases during the year, with the maximum of 0.8 t per haul in the summer. In general, the club mackered production doe not exceed 10% of that Brazilian sardinlla. The main club mackerel fishing grounds are situated in the Ilha Grande Bay and adjacent waters, reaching 84% of its annual production in Rio de Janairo State. In such fishing grounds, more than 90% of the chub mackerel catches are obteined between summer and winter, when the productivity indexes are higher. Chub mackerel is caught from the surface down to 60 m in depth, concentrating between 11 – 40 m wit higher frequency in the 21 – 30 m depth range.