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| Medeiros,Paulo Ricardo Petter; Knoppers,Bastiaan Adriaan; Cavalcante,Geórgenes Hilário; Souza,Weber Friederichs Landim de. |
| The aim of this study was to investigate the post-dam conditions of the loads and yields of dissolved inorganic nitrogen (DIN), orthophosphate (DIP, silicate (DSi) and total phosphorous (TP) in the Lower São Francisco river estuary (NE-Brazil) after the river was regulated to a constant flow by the dams. Loads and yields of monthly measurements performed from November 2000 to March 2002 at a gauging station downstream of the dams (80 km from the coast) showed 4.1 x 10³ t/yr and 0.006 t/km² /yr of DIN, 0.2 x 10³ t/yr and 0.002 t/km² /yr of DIP, and 448 x 10³ t/yr and 0.71 t/km² /yr of DSi, respectively. Over the last 15 years, DIN loads reduced by 94 % and DSi by 31%. The river turned into an oligotrophic system with primary production limited by nitrogen... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Nutrients; Fluvial loads; Dam impacts; Estuary; São Francisco River (NE-Brazil). |
| Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132011000200022 |
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| Paschoalini,Alessandro Loureiro; Perini,Violeta da Rocha; Ribeiro,Dirceu Marzulo; Formagio,Paulo Sérgio; Rizzo,Elizete; Bazzoli,Nilo. |
| The alterations to the hydrologic regime downstream from hydroelectric dams may cause an impact on the reproductive success of fishes. This study aimed to analyse the influence of the physical and chemical parameters of the water of the Grande and Pardo Rivers on gonadal maturation, oocyte diameter, follicular atresia and biological indices of Pimelodus maculatus collected from three river sections: Grande River, downstream from the Porto Colômbia dam (S1), Grande River, downstream from the confluence with the Pardo River (S2) and in the Pardo River channel (S3). Males and females captured in S1 presented significantly higher average values for total length and body weight than those captured in S2 and S3. The gonadosomatic index values were significantly... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Abiotic factors; Dam impacts; Environmental impacts; Gonadosomatic index. |
| Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252013000300615 |
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