Heavy-metal tolerance in algae isolated from contaminated lakes near Sudbury, Ontario

Abstract

Chemical analyses of lake waters in the Sudbury smelting area indicated abnormally high levels of metals, especially of copper and nickel. Two of the algal isolates from these contaminated lakes, a Scenedesmus species and a Chlorella species, were chosen for study. Their growth, as determined by cell number, was tested under controlled conditions in defined media. Nutrient conditions, pH, and concentration in solution of copper and nickel were used as variables in bioassays. In comparison with laboratory strains of similar algae, in medium with no chelate (ethylenediaminetetraacetic acid) the isolated lake strains were found to be tolerant of the heavy metals nickel (Scenedesmus) and copper (Scenedesmus and Chlorella). The patterns of response to metals in solution differed markedly between laboratory and lake strains. The ecological implications are considered.