1. Department of Biological Sciences, University of Alberta, Edmonton, Alberta, T6G 2E9 Canada, Department of Fisheries and Oceans, Freshwater Institute, 501 University Crescent, Winnipeg, Manitoba, R3T 2N6 Canada, Water Chemistry Program, University of WisconsinMadison, 660 North Park Street, Madison, Wisconsin 53706, Department of Microbiology, University of Manitoba, Winnipeg, Manitoba, R3T 2N2 Canada, and Environmental Sciences Division, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, Tennessee...