Impacts of dam construction on the macroinvertebrate community in the Poxin-Açú, in a tropical region

Abstract

River regularization plays an important role in socio economic development. However, it also modifies the natural flow system of the river and its biotic and abiotic characteristics, causing significant impacts on rivers. To evaluate the impacts on the macroinvertebrate community caused by dam construction on the Poxim-Açú River, metrics of composition and community structure of the macroinvertebrates were analyzed, as well as ecological and biological traits of the region. Macroinvertebrates were collected at three sites located downstream the dam, before (2013) and after (2015) dam construction. The water quality was classified as “good” to “excellent” according to the biotics indices. The alterations of the flow regime of the river after the dam construction influenced the macroinvertebrate communities, modifying their diversity, equitability, richness, and the number of individuals.