Estudo da distribuição espacial e vertical da Biomassa das espécies de carapau do género Decapterus ssp do norte do Banco de Sofala à sul do Banco de Boa-Paz, Moçambique

Abstract

The present study aimed to analyze the vertical and horizontal distribution of biomass, as well as the relative contribution of catches of the Mozambican horse mackerel species belonging to the genus Decapterus spp. along the Mozambican coast, with emphasis on the Sofala Bank (central region) and the Boa-Paz Bank (southern region). The study was based on a combination of scientific survey data and commercial fishery statistics. The main analyses included: (i) assessment of species composition and relative abundance, (ii) evaluation of vertical distribution patterns, and (iii) determination of length–weight relationships of the different species of Mozambican horse mackerel. The results revealed higher species diversity at the Boa-Paz Bank compared to Sofala, where a clear dominance of Decapterus russelli was observed, contributing about 60% of the catches. Regarding vertical distribution, biomass was concentrated between 0–50 meters at Boa-Paz and 0–100 meters at Sofala. Both banks showed a negative allometric growth pattern, where length increased faster than weight. D. russelli (Boa-Paz) and D. kurroides (Sofala) showed the highest coefficients of determination, while D. macarellus presented greater variability. These findings confirm the influence of environmental and biological factors on the population dynamics of the genus Decapterus in Mozambican waters.