1. Water Quality Monitoring and Surveillance Division, Water Science and Technology Directorate, Environment Canada, 867 Lakeshore Road, P.O. Box 5050, Burlington, ON L7R 4A6, Canada.
2. Environmental Monitoring and Reporting Branch, Ontario Ministry of the Environment, 125 Resources Road, Toronto, ON M9P 3V6, Canada.
3. Ecotoxicology and Wildlife Health Division, Wildlife and Landscape Science Directorate, Environment Canada, 867 Lakeshore Road, Box 5050, Burlington, ON L7R 4A6, Canada.
4. United States Environmental Protection Agency, Great Lakes National Program Office, Mail Code G-17J, 77 W. Jackson Boulevard, Chicago, IL 60604-3590, USA.