Aspectos ecológicos, sociais e econômicos da produção da tilápia (Oreochromis niloticus) em tanques-rede no açude de Coremas-PB

Abstract

This work was developed in order to evaluate the production of Tilápia (Oreochomis niloticus) in tanks-net and its possible impacts done by the cultivation. It was also done to find out about the economical and social profile of the fish farmers and fishermen. Focusing on the fishermen either on urban or rural areas, it was used limnological codeterminants and several interviews through structured and semi-structured questionnaires. The study took place Coremas municipality which is located in 7" 01 02" S and 37" 56 48" W coordinates, in an altitude of 212m in Paraíba State. In this manner, samples were done in 07 points previously chosen. In the cultivation area, the collection were done in the surface of 05 tanks-net that were represented in the study by: T1, T2, T3, T4, and T5, resting 02 point. One of them was near the cultivation area named Braço and the other one was distant and it was named Capitation. The Physical Chemistry variables analyzed were: water temperature, transparency, pH, electrical condutibility, soluble oxygen, oxygen demand, NH3, NO3, NO2, total phosphorus, sodium, potassium and the biometrical features of the specie. Statistically, the data was dealt by the measures of central tendency and significance test. The interviews tried to arise information about the level of education, family, dwellings, sanitation, family income, conditions of the cultivation, working time, species of fish, control politics and the social representation of the community. The survey took place in the summer season and there was no evidence of precipitation so the variables had no influence by this issue. The structure presents high water transparency and extense euphotic zone; the values of amonion ion is considered high to the fish farming. According to the analysed patterns the water is identified as sweet water type 1, it is a profitable activity, there was no evidence of a negative impact in the reservoirs. The community protested and affirmed that the major impacts were due to the low disposal of fish in the lakes, the predatory fishings, the lack of fiscalization by the encharged people, the high rates of illiterate people and the P.S.F. (Family Health Program) being the program the most looked for by the fishermen and their family in case of disease and also the Tucunaré (Cichla spp) the most fished in the municipality.