Qualidade da Água na Proteção das Comunidades Aquáticas na Terra Indígena Rio Formoso, em Tangará da Serra-MT Região de Transição entre os Biomas Cerrado e Amazônia

Abstract

We aimed to characterize the natural surface waters available in the Rio Formoso Indigenous Land in Tangará da Serra/MT-Brazil, according to Resolution 357/2005 of the National Environment Council (CONAMA), observing their possible destination for the protection of aquatic communities in Indigenous Lands.  We chose five hydrographic basins in which a sampling point was identified near the exutory, we made collections in 12 campaigns from September/2016 to August/2017, we tried to carry them out always close to the 15^th day of each month. The samples were obtained following the guidelines for collection and transport, being refrigerated from collection to delivery to the laboratory where they were analyzed within a maximum of 24 hours. In this study, 9 variables were analyzed, which are included in the Resolution above, namely: Hydrogenionic Potential (pH); Chloride (Cl); Total phosphorus (P); Total nitrogen (N); Biochemical Oxygen Demand (BOD); Dissolved Oxygen (DO); Total solids (TS); Turbidity (Tu); and Thermotolerant Coliform (TC). The results were grouped into two periods, one being dry (May to October) and the other rainy (November to April) and later presented by the sample mean and standard deviation for each collection point and period. The variables that contributed negatively to the results were: pH, dissolved oxygen and thermotolerant coliform. All water bodies in this study are at odds with Resolution 357/2005 for class 1 in at least one of the variables evaluated. The concentration of the variables Chlorides, Phosphorus, Nitrogen, Biochemical Oxygen Demand, Total Solids and Turbidity are within the limits of the reference resolution, fall into Class 1 and have no limitation on the preservation of aquatic life on indigenous land at any point and periods.