Experimentos eco-hidráulicos com bioindicadores bentônicos em mesocosmo fluvial

Abstract

The river flow characteristics influence directly the benthic fauna of a stream. This study aims to evaluate (i) if artificial microhabitats colonized in a stream reach similar composition, richness, and abundance of the instream assemblages and (ii) the response of a benthic community to flow changes in terms of propensity to drift. Water and invertebrates were collected on the Taboões spring, Serra do Rola Moça State Park, Belo Horizonte (MG) and transferred to hydraulic channel of CEFET-MG in order to identify the effects of hydraulic changes on the community structure of (i) invertebrates that colonized artificial micro-habitats for 71 days and (ii) invertebrates transferred directly from the stream (no pre-colonization). The results allow concluding that the process of colonization was effective, and the flow changes modified the density of Ephemeroptera and Diptera individuals in drift. The composition and richness of macroinvertebrates in the drift did not change, evidencing that benthic organisms are adapted to sudden changes of flow. These experiments will support future eco-hydraulic experiments in mesocosms in situ to test the effects of global changes on biodiversity and ecological processes in headwater streams.