IMPACTO DE CARREAMENTO DE REJEITO DE FERRO NA QUALIDADE DE ÁGUA E DA FAUNA BENTÔNICA EM RIACHO NO MUNICÍPIO DE CORUMBÁ-MS

Abstract

The study encompassed the analysis of benthic macroinvertebrate communities at five points along the Piraputangas Stream (MS), during dry (September 2022), rainy (November 2022), and transition (October 2023) periods. The aim was to investigate the potential influence of iron mining tailings on the composition and characteristics of these organisms. Metrics such as BMWP (Biological Monitoring Working Party) and ASPT (Average Score per Taxon), as well as the Shannon-Wiener Diversity Index and Pielou's Evenness, were employed. These metrics were applied to assess the relationship between macroinvertebrates and water quality, evaluated through physical, chemical, and biological parameters. Elmidae, Hydropsychidae, and Oligochaeta were the most collected groups. The most preserved sites exhibited higher richness and diversity of macroinvertebrates, including pollution-sensitive groups. Even without an ideal presence of riparian vegetation, these sites proved to be more favorable. In areas considered polluted by iron mining, higher abundances were recorded, mainly of organisms tolerant to organic pollution such as Oligochaeta, Planorbidae, and Hygrophila. Biotic indices of water quality (BMWP and ASPT) were deemed critical in most sampled points, as well as heavy metal levels, which exceeded the limits established by CONAMA Resolution 357/05.

Keywords: Benthic organisms, mining, upper Paraguay basin.