Impact of damming on the Chironomidae of the upper zone of a tropical run-of-the-river reservoir/Impacto de um represamento sobre Chironomidae do remanso de um reservatorio fio d'agua tropical
We examined the effects of the Mogi-Guacu river damming (Sao Paulo State, Brazil) on the Chironomidae fauna. Pre, during, and post-filling sampling was carried out in the main channel and margins of one site in the upper zone of the reservoir, using a modified Petersen grab (325 [cm.sup.2]). We eval...
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| Published in: | Brazilian journal of biology Vol. 76; no. 2; p. 402 |
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| Main Authors: | , , |
| Format: | Journal Article |
| Language: | English |
| Published: |
São Carlos
Association of the Brazilian Journal of Biology
01-04-2016
Instituto Internacional de Ecologia |
| Subjects: | |
| Online Access: | Get full text |
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| Summary: | We examined the effects of the Mogi-Guacu river damming (Sao Paulo State, Brazil) on the Chironomidae fauna. Pre, during, and post-filling sampling was carried out in the main channel and margins of one site in the upper zone of the reservoir, using a modified Petersen grab (325 [cm.sup.2]). We evaluated the total, subfamily, and tribe densities and also their relative abundance. Analysis of genera included densities, relative abundance, richness, and dominance. The Rosso's ecological value index (EVI) determined the ecological importance of each genus. There was a tendency of decrease of the total Chironomidae density, increase in the percentage of Chironomini, and decrease in densities and percentages of Orthocladiinae and Tanytarsini. These changes in percentage were respectively related to Polypedilum, Lopescladius, andRheotanytarsus, the genera with the highest EVI values. After-filling richness was lower in the margins and dominance of genera did not change significantly. Chironomidae in the margins was more sensitive to damming than in the main channel. This difference in sensibility sustains the use of Chironomidae as bioindicators. Damming impact was indicated by the reduction of both genera richness in the margins and relative abundance of groups typical of faster waters. The results have highlighted the need for multi-habitat analysis combined with a before-after sampling approach in the environmental impact studies concerning the damming impact on the benthic fauna. |
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| Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
| ISSN: | 1519-6984 1678-4375 |
| DOI: | 10.1590/1519-6984.16814 |