Changes in nutrient loads (N, P and Si) in the São Francisco estuary after the construction of dams
Braz. arch. biol. technol
;
54(2): 387-397, Mar.-Apr. 2011. ilus, tab
Article
in English
| LILACS
| ID: lil-582389
ABSTRACT
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 percent and DSi by 31 percent. The river turned into an oligotrophic system with primary production limited by nitrogen and nutrient yields being among the lowest of Brazilian coastal rivers.
Full text:
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Index:
LILACS (Americas)
Language:
English
Journal:
Braz. arch. biol. technol
Journal subject:
Biology
Year:
2011
Type:
Article
/
Project document
Affiliation country:
Brazil
/
Japan
Institution/Affiliation country:
Instituto Nacional de Tecnologia/BR
/
United Nations University/AE
/
Universidade Federal Fluminense/BR
/
Universidade Federal de Alagoas/BR
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