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The phytoplankton consists of a diverse set of algae that are important for the water quality of aquatic ecosystems. Studies have revealed that various organisms are directly dependent on microalgae, as well as being primary producers, they are irreplaceable sources of food. Therefore, the aimed of the study was to evaluate the limnological conditions and carry out a survey of planktonic microalgae in the Chlorophyta division of the Chlorophyceae class of the supply weir and an effluent from the Carlos Eduardo Matiazze Fish Farming Center, Presidente Médici, RO, Brazil. For that, the physical-chemical parameters temperature, oxygen dissolved in water (ODA), pH, transparency, alkalinity, hardness, electrical conductivity in water (CEA), carbon dioxide and total ammonia concentration (CAT) were analyzed. The results were compared with the norms established by CONAMA Resolution 357, of 2005 fresh waters, especially class 2. And also, the survey of chlorophytes was carried out, and the analyzes of the samples were carried out by means of slide preparations for immediate reading through the observation under the binocular optical microscope. The microalgae species of the Chlorophyta division of the Chlorophyceae class were identified in a taxonomic category of order, family, genus and species. The weir water showed acceptable values, according to CONAMA, for the parameters analyzed here for most of the year. The effluent also expressed acceptable values according to the legislation, with the exception of dissolved oxygen with a value of 1.7 mg/L. Concerning the survey of chlorophytes, it was observed that the weir is rich and diversified, which can be an indicator of pollutants and contamination since the weir is exposed to a large amount of effluents. |
