Fish diversity in the cascade of reservoirs along the Paranapanema River, southeast Brazil

Abstract

The Paranapanema River is a major tributary of the upper Paraná river basin. Eleven hydropower dams regulate its main course, but no study has investigated fish diversity in these impoundments at the basin-scale. The present study investigated spatial patterns of richness, composition, and abundance of native (non-migratory and migratory) and non-native fishes in the cascade of reservoirs along the Paranapanema River. The study is based on data collected from 34 independent studies conducted in nine reservoirs (47 samples). The compilation recorded 161 species, being 111 native (14 migratory) and 50 non-native. Total richness ranged between 56 and 112 species/reservoir, with a mean of 72 (49.9 non-migratory, 8.1 migratory and 14 non-native). The number of non-migratory species showed no spatial trend along the cascade system, but migratory and non-native richness increased toward downstream reaches. We also observed spatial variation in species composition along the cascade system, but some non-native fishes were widely distributed. Migratory fishes showed low relative abundance (usually < 10%), while non-native species were common and more abundant, especially in reservoirs downstream. Our results revealed a high diversity of fishes in the cascade of impoundments, but indicated that migratory fishes are rare, while non-native species are common or dominant.

Damming and seasonality as modulators of fish community structure in a small tributary

“…Species richness observed in this study is in accordance with some previous studies conducted in nearby areas, with an average of 40–50 species (Nobile et al, ; Pelicice, Azevedo‐Santos, Esguícero, Agostinho, & Arcifa, ; Queiroz et al, ). The diversity indices corroborated hypothesis 1 (Willis & Magnuson, ) because the transition area exhibited the greatest species richness, abundance and biomass with increase in the wet season.…”

“…In dam-free rivers, flood pulses tend to homogenise the different habitats present in a flood plain, such as rapids, river corridors and marginal lagoons (Thomaz et al, 2007), by connecting all these environment. However, in this study an inverse situation was observed, with more similar habitats in the dry season, since, in the Species richness observed in this study is in accordance with some previous studies conducted in nearby areas, with an average of 40-50 species Pelicice, Azevedo-Santos, Esguícero, Agostinho, & Arcifa, 2018;Queiroz et al, 2015Queiroz et al, , 2016.…”

Temporal changes in fish diversity in lotic and lentic environments along a reservoir cascade

“…Therefore, a better understanding of the effects of reservoir cascades on fish assemblages is necessary, particularly in Brazil, where hydropower represents the country's main energy source. Studies of reservoir cascades in Brazilian rivers have demonstrated that fish composition, richness, and functional diversity change with a longitudinal gradient along the cascade and over time (Ferrareze, Nogueira, & Sartori, 2014;Oliveira, Baumgartner, Gomes, Dias, & Agostinho, 2018;Pelicice, Azevedo-Santos, Esguícero, Agostinho, & Arcifa, 2018;Pereira et al, 2018;Petesse & Petrere, 2012;dos Santos et al, 2017), both in reservoirs (lentic environment) Bailly et al, 2016;Ortega et al, 2018), and also downstream from dams (lotic environment) (Granzotti, Miranda, Agostinho, & Gomes, 2018;de Mérona, Vigouroux, & Tejerina-Garro, 2005;Zdankus, Vaikasas, & Sabas, 2008). Impoundments change the river's flow regime by reducing variability in annual discharge and flood pulses, which in turn impact ecological processes in downstream habitat (Bunn & Arthington, 2002;Pompeu & Godinho, 2006).…”

Population and reproductive parameters of the red-tailed catfish, Phractocephalus hemioliopterus (Pimelodidae: Siluriformes), from the Xingu River, Brazil

“…This abrupt and permanent intervention in the characteristics of physical habitats may affect the reproductive and recruitment patterns of most fish species (Agostinho et al, 2004). In particular, migratory fish, like P. hemioliopterus, may be prevented from completing their reproductive migrations due to the obstruction of the river, which impedes the fish from reaching suitable spawning locations (Antonio et al, 2007;Pelicice et al, 2018), which could eventually lead to local population decline and even extinction.…”