Zooplankton functional diversity as an indicator of a long-term aquatic restoration in an Amazonian lake

Mining is an important economic activity that can have severe impacts on aquatic ecosystems. Plankton communities are commonly used as bioindicators of human-related threats to freshwater environments due to their rapid response to environmental conditions changes. Here, we used zooplankton functional diversity to understand the recovery patterns of an Amazonian lake impacted by mining activity (input of bauxite tailings) after 30 years of natural attenuation and active restoration processes. Zooplankton species richness and functional diversity (Rao's quadratic entropy-FDQ and community-level weighted means of trait values-CWM) were compared in impacted and reference areas during the flood period, in March 2015. We found a significant negative influence of turbidity on zooplankton FDQ, and similar FDQ and CWM values between the active restoration area and the reference area. These results suggest a positive effect of vegetation restoration efforts for the zooplankton community of Batata Lake. We demonstrated the utility of zooplankton functional diversity metrics as bioindicators of freshwater restoration, the response of the aquatic ecosystem to vegetation restoration and, consequently, water quality.