Figure 1. Effect of mine (MS) and synthetic (SS) seepage on growth rate of Chlorella sp.

Results are normalized to the percent of control response, and are expressed as mean ± standard error (n = 3 per tested concentration). Mine seepage toxicity data from Harford et al. [8] are also plotted. Mean ± standard error (n = 3) control growth rates (doublings/day) for the present study were as follows: MS sample 1–1.71±0.015; SS sample 1–1.71±0.015; MS sample 2–1.59±0.023; SS sample 2–1.61±0.032.