1. Department of Chemistry, McMaster University, Hamilton, Ontario, L8S 4M1 Canada,
Water Science and Technology Directorate, Environment Canada, Burlington, Ontario, L7R 4A6 Canada,
Department of Fisheries and Oceans, Fresh Water Institute, Winnipeg, Manitoba, R3T 2N6 Canada,
Ontario Ministry of the Environment, Etobicoke, Ontario, M9P 3V5 Canada