Bioaccumulation of atrazine: effects on population growth and reproduction of the rotifer Brachionus calyciflorus fed atrazine-exposed microalgae

Little information is known about bioaccumulation of atrazine or the effects it has on consumers that ingest atrazine-contaminated prey. For that reason, freshwater microalgae Chlorella vulgaris cultures were exposed to different concentrations of atrazine for twenty-four hours and were then used as an exclusive food source for Brachionus calyciflorus for three days with the intent to evaluate the effects on rotifer population growth, reproduction, and survival. Considering a multivariate response, there was a deleterious effect of feeding on atrazineexposed algae. Specifically, the rate of population growth, total ovigerous females and egg ratio (i.e. the total number of parthenogenic eggs divided by the total number of females in a population) in the rotifer populations significantly decreased as atrazine exposure concentrations of C. vulgaris increased. The rate of mixis in rotifer populations fed atrazine-exposed microalgal cells also decreased as herbicide concentration increased. The results of this study suggest that herbicides absorbed by microalgal cells can adversely affect higher trophic level organisms.