Zooplâncton como indicador da restauração de ambiente aquático impactado pela atividade de mineração: é possível recuperar a diversidade de funções

Abstract

Functional ecology appears as a tool to assessing the recovery of ecological functions in degraded ecosystems, because it provides links related the species characteristics, ecosystem functions and services. However, this approach is poorly understood for zooplankton communities. In degraded aquatic systems, the study of zooplankton functional diversity provides important information about restoring the community functional characteristics which has great importance in ecosystem processes, such as energy and matter flow. Here we compared the efficiency of natural and induced restoration processes in restoring the zooplankton functional composition and diversity. We sampled zooplankton and limnological variables in March 2015 in Batata Lake (Oriximiná - PA), an Amazonian lake that was impacted by mining activity. We evaluated zooplankton taxonomic diveristy, as well the functional diversity in six sample points from the six areas: 1) Natural pelagic area; 2) Natural igapó area; 3) Impacted pelagic area; 4) Igapó planting area; 5) Rice banks area; 6) Igapó natural restoration area. We estimate zooplankton taxonomic and functional diversity for each area. The zooplankton taxonomic and functional diversity were evaluated and compared. Zooplankton diversity patterns were related to limnological variables, by a canonical correspondence analysis (CCA). The relationship between bauxite tailings impact and functional attributes composition of each area was evaluated. We found that induced restoration process in Batata Lake had an important role in reestablishing the functional composition and diversity of zooplankton. In addition, the natural colonization of rice banks area played an active role supporting the restoration of the lake physical conditions and to restore the functional composition and diversity of zooplankton. These results complement previous studies in this particular lake, which until the present moment were based only on structural characteristics, contributing with the knowledge about the restoration of zooplankton role in the ecosystem functioning.