ABSTRACT
The goal of this study was to evaluate the water quality of Samambaia Creek (São Pedro, São Paulo, Brazil) through physical chemical parameters, trophic state index (TSI) and ecotoxicological assay with Daphnia magna. From January to December 2011 water samples were monthly collected from upstream, downstream and inside the São Pedro city, and exposed to D. magna in laboratory for 48 hours to evaluate mobility effects. Conductivity, phenols, dissolved oxygen, biochemical oxygen demand, surfactants, pH, and TSI were measured. Values of the first five parameters showed low water quality downstream of the city. Chlorophyll a values were within the range permitted by the Brazilian environmental legislation and thus the TSI in Samambaia Creek was classified as ultra-oligotrophic for most sites and months. Water samples collected from January to April downstream of São Pedro were toxic to D. magna. The physical chemical analysis and the toxicity test indicate low quality of water from Samambaia Creek downstream the city of São Pedro.
Keywords:
ecotoxicological assay; microcrustaceans; mobility;water quality
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