Preserved or not preserved? How much the quality of a stream can improve in a conservation area, even when the spring is urbanized

• Ano de defesa: 2021
• Autor(a) principal: Ferreira, Douglas da Silva
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Universidade Federal de Viçosa
• Palavras-chave em Português: Insetos aquáticos; Biologia de conservação; Esgotos; Monitorização biológica; Indicadores ambientais; Poluição; Ecologia de Ecossistemas
• Link de acesso: https://locus.ufv.br//handle/123456789/29075; https://doi.org/10.47328/ufvbbt.2021.114

Rapid urbanization in Brazil has been dramatically deteriorating the water quality of streams and threatening aquatic ecosystem health. In this study, we aimed to address the question of how urbanization affects macroinvertebrate distribution patterns and the water quality of a strategic stream that runs from the city to an important conservation area. Environmental variables (spatial and temporal) and macroinvertebrate community (use of community deconstruction) data were collected on rainy and dry seasons of 2019 and 2020 at 10 sampling sites, of which four we categorized as impacted, three as altered and three as pristine, based on environment assessment protocols. We submitted the abundance and taxonomic richness data to a two-way ANOVA, then to a GLMMs. We also performed a nMDS to the macroinvertebrate community, followed by the ANOSIM and SIMPER test, respectively. The results of this study showed that impacted and altered streams had lower total richness and % Odonata, and higher % Chironomidae when compared to pristine streams. As expected Chironomidae had a positive relationship with total coliforms, and taxonomic richness and % EPT had a negative one, and % Odonata had a negative relationship with total dissolved nitrogen. Pristine stream community of benthic macroinvertebrates showed different composition between impacted and altered streams, however, communities of impacted and altered environments were generally similar. Our exploratory data showed that gathering collectors were representative in impacted and altered streams, and predators were representative in pristine areas. Moreover, our results suggest that urbanization resulted in less diverse and more tolerant stream macroinvertebrate assemblages. Keywords: Aquatic insects. Conservation. Biomonitoring. Urban stream. Domestic sewage. Ecological indicator. Pollution.