The nitrogen cycle in freshwater environments and anthropic interference

The correlation between the nitrogen cycle in the freshwater environment must be analyzed and monitored because it interacts with the ecosystem directly and indirectly and can be altered by dumping domestic sewage and excess organic matter. This work aimed to demonstrate the relationship between the nitrogen cycle and the consequences of the saturation of this component in freshwater aquatic environments, in addition to highlighting the association with bioindicators such as water lilies (Eichhornia sp), water lettuce (Pistia sp) and jaguar's ear (Salvinia sp) with this chemical element. The method used was exploratory and deductive with the application of three stages (survey of studies on the subject, the chronology of literature, and statistical treatment of data) described in the Simple Multi-Attribute Rating Technique method using Exploiting Rankings (SMARTER). The data obtained and analyzed indicated that the biological accumulation caused by the excess of bioavailable nitrogen in aquatic environments, by the insertion of industrial and domestic effluents, and this contributes to the flowering or bloom of cyanobacteria, in addition to decomposing microorganisms such as bacteria of the genera Nitrossomonas spp, Nitrosococcus spp, and Nitrospira spp. Then, the excess or low concentration of this chemical element directly affects living organisms (phytoplankton). Therefore, those human actions intervene negatively in such environments, however, these effects are mitigated by the presence of the water lily, water lettuce and jaguar ear determine the absorption of the excess amount of nitrogen, as well as indicate the state of conservation of the freshwater aquatic ecosystem; however, it is recommended to control these populations so that no degradation of water quality occurs.