Ecotoxicological evaluation of water of the hydrographic Basin of the Una River using the bioindicator Ceriodaphnia dubia
Keywords:
toxicity, cladoceran, river Una basin
Abstract
The majority of the Una River Basin is located in Taubaté County and contributes significantly to its water supply. The main goal of this research was to evaluate the water quality of the Una River using the microcrustacean C. dubia as bioindicator for tests of chronic and acute toxicity. Bimonthly water samples were obtained from each of six localities throughout the Una Basin, from March to October, 2011. Physical-chemical water parameters such as pH, electrical conductivity, hardness, dissolved oxygen and precipitation were measured and correlated to the C. dubia reproductive rates. No significant relationships were found between the water’s electrical conductivity and precipitation with respect to bioindicator reproductive rates. However, at the Sete Voltas, Antas and Rocinha Sub-Basins, significant interactions were detected between some water parameters and reproductive rates, suggesting that water may constrain the reproduction of C. dubia. Acute toxicity was not detected in any of the six sites, while chronic toxicity was recorded at Rocinha, Sete Voltas, Antas, Médio and Baixo Una Sub-Basins. In general, the water quality of the Una Basin, as indicated by the absence of acute toxicity, still remains in an acceptable conservation condition. Caution is needed, however, since slight pollution sources are causing chronic toxicity in some localities. In addition, as the microcrustacean C. dubia, appeared to be a reliable bioindicator in this investigation, we suggest that it be used for continuous water quality monitoring programs.
Published
19/08/2014
Issue
Section
Special
Authors maintain the copyrights for their work. However, they grant rights of first publication to Ambiente e Agua - An Interdisciplinary Journal of Applied Science. In compensation, the journal can transfer the copyrights, allowing non-commercial use of the article including the right of sending the article to other data bases or publication media. The journal uses the CC BY 4.0 license"