Comparisons of single-species, microcosm and experimental pond responses to atrazine exposure

摘要: Results from single-species toxicity tests form the basis for guidance about concentrations of chemicals that are likely to be environmentally hazardous. Microcosm bioassays have been proposed as better tools this purpose under some circumstances. Rarely comparisons made among responses in various test systems and those seen natural communities. We compared algal assays, a synthetic microcosm (the Taub microcosm) experimental ponds exposed similar atrazine by comparing reduced activity or biomass 50% control values (EC50). Eight species were examined; mean EC50 14C uptake ranged 37 308 μg/L. For microcosm, 103 159 μg/L uptake, 126 165 dissolved oxygen production 106 164 consumption. Values dependent on time intervals selected calculations. In ponds, 100 chlorophyll a, 82 The basic similarity across suggests results combination provided reasonable estimate concentration produced direct effects more