Diversidade, distribuição e abundância da ictiofauna dermersal do Nordeste do Brasil

Abstract

Despite the social, ecologic and economic importance of the Brazilian northeast coast, knowledge regarding to biodiversity, assemblage structure and fish species distribution are still scarce, especially when related to environmental factors, which make difficult the implementation of ecosystem-based and sustainable management strategies. In this study, we describe the fish demersal assemblage along the continental shelf of the northeast Brazilian cost, specifically the ecological descriptors and the distribution and spatial abundance of the fish fauna. Sampling was conducted at 37 stations on board the R/V ANTEA, Between the latitudes 5°S-9°S. Fish species were described considering abundance (N° of individuals), biomass (weight) and frequency of occurrence. Community structure was investigated through ANOSIM and SIMPER analysis, while a DISTLM was performed to evaluate the influence of physical-chemical factors on the variability of fish data. Diversity was expressed as a series of indices and represented through maps. A total of 7.340 individuals (830 Kg), distributed in 24 orders, 49 families and 120 species, were collected. Haemulidae, Mullidae and Holocentridae were the most abundant families. The most frequent species were Hypanus marianae, Lutjanus synagris and Pseudupeneus maculatus. Higher abundance values were found in the central and south part of Pernambuco; however, considering biomass, higher values were also found in Rio Grande do Norte. Regarding to richness, higher values were found in Paraiba (PB) and south of Pernambuco (PE), while, considering diversity, high values were found along the entire study area. Comparatively with other regions in Brazil and around the world, the Brazilian northeast continental shelf can be described as an area of high fish species richness and diversity. DistLM analyses identified that depth, latitude and temperature explained 20% of the variation in the fish assemblage. Considering information found in this study, we consider the south of Pernambuco (8°30’S - 9°S), north of Rio Grande do North (5°S - 5°30’S) and the state of Paraiba (6°30’S - 8°S) as priority areas for the development of management plans and conservation of marine ecosystems.