Aim 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.

ResumoNos últimos quarenta anos, o Parque Estadual do Itacolomi (PEI), localizado na região de Ouro Preto, Minas Gerais, esteve sujeito a várias mudanças em seus padrões de uso e ocupação do solo. Essas mudanças foram registradas e quantifi cadas através de sensoriamento remoto e técnicas de geoprocessamento, com as quais se efetuou o mapeamento das transformações no uso e na ocupação da área durante essas quatro décadas. A fi m de se avaliarem as mudanças no uso e ocupação, foram defi nidas as seguintes classes vegetacionais: Floresta Estacional Semidecidual, Campos Rupestres e Áreas Antropogênicas. Primeiramente, foram comparados os mapeamentos de uso da terra de 1966 e 1974, defi nidos como primeiro período de análise, depois, 1974 e 1986, considerados segundo período de análise; e, por último, o terceiro período de análise: 1986 e 2000. As mudanças que ocorreram no PEI foram predominantemente de origem antrópica, com uma maior intensidade nos anos setenta. Como resultado do abandono dessas atividades e, também, devido a um maior monitoramento e controle das ações antrópicas efetuadas no PEI nas décadas seguintes, as áreas abandonadas foram pouco a pouco sendo ocupadas por plantas pioneiras como as candeias, recuperando a região. Palavras-chave:Mudança do uso da terra, geoprocessamento, sistema de informação geográfi ca, análise multitemporal, Parque Itacolomi, Minas Gerais. Abstract

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PurposeThe purpose of this research was to identify the major environmental impacts occurring in Melo Creek, Minas Gerais, Brazil, especially as regards to its water quality.Design/methodology/approachInitial evaluation was based on aerial photograph interpretation. All the small creek catchments were delimited and 12 stream segments were chosen for sampling and analyses. The segments had their water discharge calculated and channel pattern described. Also determined for these segments were the physical and chemical parameters of the water, as well as the microbiological content. Both water and sediment samples were analyzed for metals and trace element quantification. Meanwhile, an environmental inquiry was conducted in all the small villages along the creek.FindingsData show a decrease in water discharge during the last decades, related to the increased destruction of the Atlantic Forest, especially at the riverheads and in permanent preservation areas (PPA). Most of the native vegetation was cut down to create farmlands and pasture. The water quality is also diminishing because for most of the properties, the main activities are pig raising and sugarcane liqueur production, which discharge their untreated effluents, along with domestic wastewater and sewage, directly into the creek. The results indicated that during its passage through the catchment, stream water became significantly contaminated with fecal coliform bacteria. As a consequence, the area possesses a high endemic disease index for water transmitted parasitism, especially for Schistosomiasis mansoni.Originality/valueThis was the first study done in the Melo catchment, a small rural basin without basic sanitation and with a highly prevalent schistosomiasis rate.