ASSESSMENT OF THE SINOS RIVER BASIN WATER QUALITY THROUGH BMWP, STATE OF RIO GRANDE DO SUL, BRAZIL

The aquatic macroinvertebrate fauna is an important component of continental limnic ecosystems, acting in several processes of important biocomplexity.Benthic macroinvertebrates are an important tool in the evaluation of the quality of aquatic ecosystems, due to their particularities and occurrences in the environment.The present study characterized the structure of the macroinvertebrate community and evaluated water quality through the application of the index "Biological Monitoring Working Party" (BMWP), in Sinos River Hydrographic Basin (SRHB), RS.Sampling was carried out from January to December 2023 at three points in the basin, abiotic variables were recorded and, in the laboratory, the sampled animals were screened, identified to family and quantified.The BMWP was calculated for each point and values for invertebrate families were also adjusted for the basin in question.A total of 2,568 specimens were sampled over the period and used for the final calculation of the index, generating the BMWP Sinos Index .The Paranhana River is the most impacted in the SRHB, and contributes to the deterioration of the waters of the Sinos River, from the Municipality of Taquara, the final value totaled a score of 102, with the water being considered polluted.The point located in the Sinos River itself and the one located in the Rolante River presented similar results (253 and 262 respectively) with positive evaluations (non-polluted waters).