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| Author(s): |
Welber Senteio Smith
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | São Carlos. |
| Institution: | Universidade de São Paulo (USP). Escola de Engenharia de São Carlos (EESC/SBD) |
| Defense date: | 2004-08-27 |
| Examining board members: |
Evaldo Luiz Gaeta Espíndola;
Walter Barrella;
Mauro César Lambert de Brito Ribeiro;
Odete Rocha;
Virginia Sanches Uieda
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| Advisor: | Evaldo Luiz Gaeta Espíndola |
| Abstract | |
This research was developed at reservoirs and tributaries from the medium and low Tietê river section, São Paulo state, aiming to evaluate the modifications occurred on the fish fauna due to the impoundment, introduction of species and environmental modifications layed on the reservoir as a result of its multiple uses. To attend the objectives proposed, usual parameters for fish community structures studies had been used, as well as limnological varieties determination, stomachal content analysisand ecomorphology. To amplify the temporal analysis (decades), bibliographic researchs about an anterior to the impoundments period were used, allowing to evaluate the effects of the impoundments. The results evidenced several alterations on the fish fauna composition in the last years and decades, mainly in relation to the loss of reophilic species and introduction of exotic and alóctone species. At this moment, the Characiphorms are more abundant, with species adaptated to lentic environment, and a reduction on the Siluriforms abundance was verified. A richness and diversity gradient of species had been observed at the Tietê reservoirs, ocurring a clear reduction from Barra Bonita to Três Irmãos reservoirs. However, no significative differences were verified between the reservoirs and tributaries for the species richness and diversity. Important ecomorphological and trophic characterization had been accomplished for the fish species from the reservoirs and tributaries, allowing a wide evaluation of the fish fauna. (AU) | |