Assessing the impacts of mining activities on zooplankton functional diversity

Abstract

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.

Rotifer community structure in fish-farming systems associated with a Neotropical semiarid reservoir in north-eastern Brazil

“…The microphagous rotifers dominated in all the three environments studied and during all the time of research, suggesting a functional redundancy of the species of rotifers in eutrophic reservoirs. A similar result was observed by Moreira, Leite, Fujaco, Mendonça, Campos and Eskinazi‐Sant′Anna (), who studied two small reservoirs impacted by mining activities, and observed a predominance of small microphages (<249 μm), not being observed alternation of trophic guilds. According to these authors, the identification of resilient zooplankton species can allow us to predict which species are essential for the maintenance of the primary ecological processes in impacted aquatic ecosystems.…”

Rotifera De Reservatórios Com Diferentes Exposições Antrópicas Em Um Fragmento Protegido De Mata Atlântica

“…Dessa forma, a dominância dos micrófagos na condição Expostos, assim como grande participação de GMIC, pode estar associada à maior quantidade de recurso alimentar disponível para os micrófagos. Outros estudos tem mostrado a dominância de micrófagos em reservatórios que sofrem com impactos antrópicos, sendo a maior parte composta pelos PMIC (Moreira et al 2016), confirmando a baixa diversidade e redundância funcional, provavelmente causadas pelas condições ambientais e recursos alimentares disponíveis. Tal fato ocorre por ambientes perturbados apresentarem teias alimentares mais simples, com grande participação de espécies tolerantes (Harig & Bain 1998).…”

“…Quanto aos grupos funcionais, os gêneros de rotíferos foram classificados em dois grupos de acordo com a estratégia alimentar definida pelo tipo de mástax, sendo: (i) Micrófagos (MIC): Maleado (Anuraeopsis, Brachionus, Epiphanes, Euchlanis, Keratella, Lecane, Lepadella, Macrochaetus, Mytilina, Plationus, Platyias, Trichotria), ramado (Bdelloida, Rotaria) e maleoramado (Filinia, Testudinella); e (ii) Raptoriais (RAP): Incudado (Asplanchnopus, Asplanchna) e vergado (Trichocerca). Devido ao amplo espectro de tamanho dos micrófagos, estes ainda foram divididos em dois subgrupos: Pequenos micrófagos (PMIC; tamanho ≤ 249 µm) e grandes micrófagos (GMIC; > 250 µm) (Moreira et al 2016). A avaliação dos grupos funcionais foi realizada através do índice de Guild Ratio (GR), resultado do cálculo: GR'= R (biomassa raptorial -biomassa de micrófagos) / R (biomassa total de rotíferos).…”

An overview of Cladoceran studies conducted in mine water impacted lakes

“…In species level, C. sphaericus was able to remain relatively unharmed by pollution. Moreira et al (2016) compared zooplankton communities in two artificial lakes, in Mata Porcos, Brazil, which receive mining effluent from two different mines. The cladoceran community in the lake which was affected by kaolinite mining (pH 6.8-0.7.1, EC 12.1-16.2 lS/cm, barium 24.0-53.3 lg/L, manganese 66.3-248.7 lg/L, zinc 0.0-12.5 lg/L) was dominated by B. longirostris, whereas the cladoceran assemblage was more diverse (Eubosmina tubicen, Bosminopsis deitersis, Alonella clathratula, Ilyocryptus spinifer) in the lake which was affected by iron mine effluent (pH 5.4-6.4, EC 2.9-18.1 lS/cm, barium 4.2-6.9 lg/L, manganese 12.4-109.7 lg/L, zinc 4.2-68.9 lg/L).…”