Biodiversity assessment of benthic macroinvertebrates along a reservoir cascade in the lower São Francisco river (northeastern Brazil)

Brazilian Journal of Biology

M. Callisto²  M. Goulart²  F. A. R. Barbosa²  O. Rocha¹ 

[1] ,Federal University of Minas Gerais Dept. General Biology Belo Horizonte Minas Gerais ,Brazil

关键词: benthic macroinvertebrates;    reservoir;    biodiversity assessment;    reservoir cascade concept;    São Francisco river;    macroinvertebrados bentônicos;    reservatórios;    avaliação da biodiversidade;    conceito de cascata de reservatórios;    rio São Francisco;   

DOI  :  10.1590/S1519-69842005000200006

来源: SciELO

【 摘 要 】

In order to verify the cascade-system effect in benthic macroinvertebrate communities, and the implications for policy making and proposals for conservation and sustainable use of the lower portion of São Francisco river basin (Bahia State, Brazil), a three-reservoir cascade system including two stretches downstream were studied during dry (June, 1997) and rainy (March, 1998) periods. The dominant groups found were Mollusca (Melanoides tuberculata), Oligochaeta, and Chironomidae larvae. Low Shannon-Wiener and Pielou index values were found, but with no significant difference between the sampling periods. However, density and taxonomic richness were significantly different (t(0.05; 31) = -2.1945; p < 0.05; e t(0.05; 31) = -3.0600; p < 0.01) between the sampling periods, with a reduction in the number of taxaand macroinvertebrate abundance during the rainy period. An increasing gradient in benthic macroinvertebrate community structures was noted along the reservoir cascade from the first reservoir (Apolônio Sales), followed by a decrease downstream from the third reservoir of the system (Xingó). Despite the negative consequences of rapid proliferation of dams, which have caused widespread loss of freshwater habitats, the reservoir cascade system promoted an increase in benthic macroinvertebrate diversity, due to water-quality improvement along the system.

【 授权许可】

CC BY   
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