Arcellaceans as pollution indicators in mine tailing contaminated lakes near Cobalt, Ontario, Canada

Six assemblages resulting from Q-mode cluster analysis of 27 arcellacean taxa in thirty-nine sediment-water interface samples collected from two small lakes heavily polluted by mine tailings near the town of Cobalt, northeastern Ontario, Canada, correlated well with various distinct polluted and remediated environments. Results of R-mode cluster analysis indicated that arcellacean strains within the same species often discriminate between environments, thus utilization of infraspecific categories increases resolution when studying lake microenvironments, pollutants, and rates of lake remediation. Results of this study suggest that successful lake remediation in these and similarly polluted lakes is best achieved by leaving the tailings undisturbed to be buried naturally, or to speed the process by addition of an allochthonous sediment cap.