Estudo comparativo da assembleia de peixes em ambientes lóticos e lênticos, em duas PCHs, Rio Veríssimo, Goiás, Brasil

Abstract

The construction of Small Hydroelectric Power Plants (SHPPs) causes significant changes in aquatic ecosystems, particularly in fish community structure. This study aimed to characterize and compare fish assemblages in lotic (pre-impoundment) and lentic (post-impoundment) environments within the influence area of the Goiandira and Nova Aurora SHPPs, located in the Veríssimo River, Goiás, Brazil. Sampling was conducted during four field campaigns, covering rainy and dry seasons before and after reservoir filling. Different capture methods were employed, including gillnets, minnow traps, sieves, cast nets, and seine nets. A total of 2,897 individuals were recorded, belonging to 58 species, 31 genera, 12 families, and 4 orders. Lentic environments showed higher abundance and species richness, especially during the dry season, with 1,016 individuals and 37 recorded species. Similarity analyses revealed differences between lotic and lentic fish communities, indicating that damming influenced the composition of the ichthyofauna. Trophic level assessment showed a predominance of omnivorous and detritivorous species. The results demonstrate that river impoundment alters fish community structure, affecting species diversity, abundance, and feeding habits.