Limnetica 38

Aquatic insects are the most widely used organisms in freshwater biomonitoring of human impacts and can provide reliable information on habitat and water quality. The Brazilian Cerrado has received strong anthropogenic impacts over the last decades, including the massive use of fertilizers in agriculture containing different concentrations of metals, with high potential of aquatic ecosystem contamination. In this context, this paper compared bioaccumulation of heavy metals among four trophic groups of aquatic insects from Cerrado streams. Sampling of sediments and aquatic insects for metal analysis (Cu, Mn, Cd and Zn) and for the bioaccumulation factor (BAF) calculation was performed from April to July, 2012. All metals were found in the stream sediments. Analysis of variance (ANOVA) showed no differences in metal concentrations among feeding guilds for Zn and Cu (F3,8 = 0.045; p > 0.005; H = 4.641; p > 0.005 respectively). With respect to manganese, the predators accumulated significantly lower concentrations than collector gatherers (F3,8 = 20.416; p < 0.05, Tukey < 0.05). Cadmium was not detected in the fauna. The results of the present study suggested that the use of aquatic insects as bioindicators might be an important strategy to detect metal pollution in aquatic environments.