Avaliação da qualidade ambiental do açude Boqueirão do Cais (Cuité – PB), por meio de indicadores biológicos.

Abstract

The characteristics of the Brazilian watersheds have been changed through different anthropic interference. Changes in these watersheds, like the River Basin Jacú, where is inserted the Boqueirão Cais that supplies the cities of Nova Floresta, Cuité and present socio-economic, cultural and environmental factors, since many cities develop around rivers that compose it. These rivers are used of different ways by the local population from fundraising activities for water consumption, through subsistence activities and leisure until the release of tailings, where may be one of the causes of pollution in the dam. This work focuses on the objective to evaluate the environmental quality of the dam through changes of meiofauna community, for it held a collection of organisms meiofaunísticos between higher rainfall and a dry period in at six points around the dam, by methodology known for meiofauna organisms. In the same periods was collected for measurement of sediment organic matter and granulometric parameters and water for pH measurement. Our results showed that in both collects there was no variation in pH between points prospected. With relation to organic matter in the rainy season the highest values were at points 4 and 6 and in the dry season was the highest in point 5. The sand fractions were larger at all points prospected being dominated by fractions thicker and thicker gaskets. Among the biotic factors in the rainy eight taxons were found, with the highest densities for the following groups: Oligochaeta, Polychaeta and Nematoda, in the dry season, we found 6 taxons, where presented the highest densities were groups: Turbellaria and Ostracoda, high lighting the absence of Nematoda, this period for meiofauna is a group of great importance as biological indicators. The Ostracoda were the most frequent in both periods studied. On relative abundance to highlight the greatest abundance Polychaeta and Ostracoda in the rainy season and Ostracoda, Oligochaeta and Turbellaria in the dry season. The community structure found in all the extension of the dam, considering the values of diversity and equitability found, which shows us the stages where organic enrichment is higher, ie during rainy there to favoring vermiform organisms, calling attention to these organic discharges during this period, which may compromise the potability of the water dam.