Biodiversidade e distribuição de diatomáceas epilíticas em corpos hídricos rurais de municípios da Região das Missões - RS

Abstract

The adverse effects of pollution on the environment have altered the characteristics and the quality of water resources, resulting in environmental damage mainly arising from human activities. Thus, this study aimed to assess the physico-chemical and microbiological parameters of the surface waters in lotic environments, using as bioindicator the epilithic diatom algae, in six municipalities of Missões Region – RS. Therefore, the parameters UV absorbance (λ-254 nm), total coliforms and Escherichia coli (presence/absence), electric conductivity (μS cm-1), apparent color (uH), nitrate (mg L-1), dissolved oxygen (OD) (mg L 1), potential of hydrogen (pH,) sedimentable solids (mL L-1), temperature (°C) and turbidity (uT) and; simultaneously, the abundance and diversity of epilithic diatom algae associated to artificial rocky substrates, in the month of October of the year 2019. The results related to the physico-chemical presented values below those stablished in Resolution of the National Environment Council (CONAMA) n° 357/2005 and Resolution of the State Environment Council (CONSEMA) n° 355/2017 and, regarding to the microbiological parameters it was identified the presence of total coliforms and Escherichia coli in all the monitored lotic environments. For the epilithic diatoms, the dominant species were identified as Amphipleura lindheimeri (municipality 1); Adlafia drouetiana (municipality 2) e Cocconeis placentula var. placentula (municipality 3), and, it can be inferred that these species are typical of oligotrophic and mesotrophic environments. Lastly, it can be observed that epilithic diatoms are presented as a bioindicator of water quality in lotic environments.