Influência de variáveis climáticas na pesca artesanal de Macau-RN.

Abstract

The research’s aim was to analyze the influence of climatic variables in the artisanal fishery, regarding a period of 10 years, in Ponta do Tubarão State Reserve of Sustainable Development (RDSEPT), Macau City, Rio Grande do Norte State, Brazil. Furthermore, the identification and characterization of the areas in which the artisanal fishery takes place, the identification of the main anthropic actions in such areas, the analysis of the temporal variability of the off-loaded fish species in the reserve as well as its correlation with climatic variables were performed. The study was based in the analysis of monthly and annual time series data, regarding the period from 2001 to 2011, of the four main off-loaded fish species and also of meteorological data. These series were analyzed using the multiple linear regression template, performed by Statistical Package Social Science software, version 13.0. In order to identify the several boat types and fishing devices used in RDSEPT, data from Fisheries Statistics Project of Technical Division of IBAMA-RN were analyzed. The temporal analysis of the main fish species was performed by STATISTICA software, version 7.0. The anthropic actions in fishing areas were identified through photographic registry of the places in which they were developed. The analysis of fecal coliform bacteria count and nitrate levels in water samples were performed according to specific methodologies. 76 questionnaires were applied to the fishermen on duty in the community (Z-41) in order to gather socioeconomic and environmental information. The dominant species in artisanal fishery in RDSEPT are: Opisthonema oglinum (Atlantic thread herring), Hirundichthys affinis (flying fish), Mugil curema (white mullet) e Coryphaena hippurus (dolphin fish). The acquired nitrate levels were within normal limits, except these from well water samples, and the thermotolerant coliform counts were beyond limits, results due to poor sanitary conditions. The variability of the main off-loaded fish species as a function of time showed regularity, year by year. Atlantic thread herring data showed regularity from July to September; flying fish and dolphin fish data revealed regularity from April to June and from September to November, respectively, and a prey-predator relation was also evidenced. White mullet data showed regularity in March. The coefficients of determination of the three main off-loaded fish species and climatic variables were significant. Atlantic thread herring data vs. climatic variables showed a high coefficient of determination. Flying fish and dolphin fish data had a moderate coefficient and white mullet had a very low value of it. The artisanal fishery is the socioeconomic activity of the major people of the reserve, attending familiar consumption as well as commercialization with middlemen.