Navegando por Autor "Campos, Larissa Paraguassú"

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    Assessing the impacts of mining activities on zooplankton functional diversity.
    (2016) Moreira, Francisco Wagner Araujo; Leite, Mariangela Garcia Praça; Fujaco, Maria Augusta Gonçalves; Mendonça, Fellipe Pinheiro Chagas; Campos, Larissa Paraguassú; Sant'Anna, Eneida Maria Eskinazi
    Mining activities generate countless environmental impacts, including heavy-metal contamination, sorting and increased turbidity. In aquatic ecosystems these impacts can drastically affect the initial links of the food chain, such as zooplankton. Methods: To evaluate how the different mining activities can influence the structure and functional diversity of zooplankton, we investigated the geochemical characteristics of the water and sediment in two small impoundments impacted by different mining activities (kaolin and iron extraction). We also explored zooplankton composition, species diversity and functional diversity (feeding guilds taxa). Results: As expected, the water and the sediment of both of the reservoirs showed high concentrations of trace elements, particularly Al, Ba, Fe, Mg, Mn, Sr and Zn. Zooplankton biomass and diversity were markedly reduced (< 12 μg.DW.L-1 and H’ < 1.5, respectively), and negatively correlated with turbidity and total suspended solids. Small microphages dominated the trophic composition of zooplankton, and an alternation of trophic guilds was not observed, since the dynamics of raptorial organisms was essentially linked to the temporal fluctuation of a single species of rotifer (Polyarthra cf. dolichoptera). Conclusions: In addition to changes in the aquatic habitat and zooplankton composition, the functional niches were also affected by the mining impacts. The use of the functional diversity analysis can emerge as a valuable approach to understand how zooplankton communities respond to drastic environmental changes.
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    Impacts of mining in artificial lake of Iron Quadrangle-MG : past marks and changes of the present.
    (2019) Campos, Larissa Paraguassú; Leite, Mariangela Garcia Praça; Moreira, Francisco Wagner Araujo; Mendonça, Fellipe Pinheiro Chagas; Sant'Anna, Eneida Maria Eskinazi
    A locus of intense mining activity since the seventeenth century, the Iron Quadrangle, corresponds to one of the most important mineral provinces in the world. Located in Minas Gerais, Brazil, it keeps in its territory marks of past mining activities still in expansion. Such changes, recorded in water bodies of the region’s watersheds, impact not only locally, but also reach adjacent ecosystems as well as those located downstream of mining companies. In this situation, an artificial lake is found in the upper course of the Mata Porcos creek sub-basin. The area was once an old place of gold exploration in the eighteenth and nineteenth centuries, and is currently influenced by active iron mining and inactive iron–manganese mining upstream. With the aim of evaluating this reservoir and contributing to the understanding of lentic systems under the influence of mining, this study analyzed the physical and chemical characteristics of sediments from the bottom of this lake, identifying the possible contributions of anthropic origin. Sediment samples were collected at nine points along two hydrological years and then submitted to granulometric, mineralogical and geochemical analyses. The geochemical signature of this lake is marked by As, Fe and Mn elements associated with both the local geological substrate and anthropic activities undertaken in the surroundings. Due to the high As concentrations, distribution maps were made using the IDW interpolation method to understand the distribution of this potentially toxic element that has a strong correlation with gold mining practiced for more than 300 years at the site.