A pesca de pequena escala nos litorais setentrional e oriental do Rio Grande do Norte

Abstract

The coast of Rio Grande do Norte, due to its geographical orientation, has characteristics that distinguish it from other coastal areas of Northeastern Brazil. With different climatological, geomorphological and phytogeographical features, the coastline is divided into two distinct areas: northern and eastern, where the fleet of small-scale crafts with great effectiveness. Despite being an activity of great socioeconomic importance, this sector is currently experiencing difficulties in their planning, due to its high complexity, making it difficult to obtain necessary information for evaluation and monitoring of fisheries. Therefore, the central goal of this research work was to analyze the bioecology of marine fishes and the fisheries dynamics, considering the geographical orientation and the seasonal changes of climatic conditions off the coast of Rio Grande do Norte. The data used were obtained during the execution of the Project of Fishery Statistics in Rio Grande do Norte, coordinated by the Center for Research and Management of Fisheries Resources of the Northeast Coast and developed by the Executive Management of the Brazilian Institute of Environment and Renewable Natural Resources from January 2005 to December 2006. To meet the goals, the bioecology of marine fishes was assessed concerning four ecological components: composition, characterization, abundance and diversity, evaluating possible seasonal differences in the last two components, which were later described and correlated with the biology of target species. Considering the fisheries dynamics, this was analyzed through four fishing parameters: characterization, fishing effort, yield and species composition, also evaluating possible seasonal differences in relation to the main targeted species. Multivariate techniques were used in order to synthesize the structure of data variability, making it easier to interpret the results. Thus, the Northern coast showed a seasonal environment with the presence of an important upwelling area, where the structure of the ichthyofauna was defined as low species diversity and composed by pelagic species with high biomass levels. Based on this structure, the main features of this area corresponded to fishing for flying fish and dolphin fish, with the rowing boat/scoop net showing the best performance in the catching of those species, which is more effective at the rainy season due to the reproductive period of flying fish. The Eastern coast showed different characteristics to those of the Northern one, with a more stable environment due to the presence of a large complex of coral reefs, where the structure of the ichthyofauna showed high species diversity of demersal species with low individual abundance. According to this configuration, the main features of this area were related to several species of the families Lutjanidae, Haemulidae and Carangidae, and the raft and hand-line appearing as the most important fisheries dynamics proved the hypothesis, which was: “The environmental peculiarities of the Northern and Eastern coastal of Rio Grande do Norte State model the structure of the ichthyofauna and imply different harvesting strategies implemented by small-scale fisheries”.