Impacts on Tocantins River aquatic ecosystems resulting from the development of the hydropower potential

Abstract

Regardless the obvious success of using hydropower plants to supply energy for economic development, they may result in several environmental and social impacts with different levels of severity on the aquatic ecosystems and on the human communities living in the region. The objective of this study was to identify environmental problems and impacts to the aquatic ecosystems in Tocantins river related to the development of its hydropower potential and contribute to the target of balancing of energy generation with biodiversity and genetic flux preservation. The scenario considered the hydropower plants Peixe Angical and São Salvador. The Causal Chain Analysis (CCA) was used to identify the environmental impacts and their immediate, sectarian and root causes. The impacts were ranked according to the characterization matrix, having the fish communities as the main indicators. The most relevant impacts were: (i) degradation of water resources, (ii) loss and changes in habitats, (iii) changes in the ecosystems stability, (iv) reduction of fish stocks, (v) interference with benthic communities and microorganism’s populations, (vi) changes in the food-chain and (vii) interference with the dispersion of fishes and mammals.