Abstract

CORDOVA, Salomé; GAETE, Hernán; ARANGUIZ, Fernanda  and  FIGUEROA, Ricardo. Water quality assessment in the Limache stream (central Chile), using bioindicators and bioassays. Lat. Am. J. Aquat. Res. [online]. 2009, vol.37, n.2, pp.199-209. ISSN 0718-560X.

The water quality in the Limache stream was evaluated at five sampling stations during the pe-riod of low water flow. At each station, aquatic macroinvertebrates were collected and the following parame-ters were measured in situ: pH, conductivity, dissolved oxygen, and total dissolved solids. The biological oxy-gen demand, total phosphorus, and total nitrogen were determined in the laboratory. Water toxicity was deter-mined through toxicity bioassays with the microalga Pseudokirchrneriella subcapitata. Thirty-three macroin-vertebrate families were found and the dominant taxa were Dugessidae, Oligochaeta and Chironomidae. A significant correlation was found among the Family Biotic índex ChFBI, conductivity, and total dissolved solids (r = 0.92; p < 0.05). Species diversity was lowest, as was the growth rate of P. subcapitata, at the stations with the greatest anthropogenic activity and in the discharge zone of a domestic wastewater treatment plant.

Keywords : water quality; aquatic macroinvertebrates; toxicity; Pseudokirchrneriella subcapitata; Chile.

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