1. Graduate School of Oceanography, University of Rhode Island, Narragansett, Rhode Island 02882-1197, United States
2. Environment and Climate Change Canada, Aquatic Contaminants Research Division, 867 Lakeshore Road, Burlington, Ontario L7S 1A1, Canada
3. Ontario Ministry of the Environment, Conservation and Parks, Environmental Monitoring and Reporting Branch, 125 Resources Road, Toronto, Ontario M9P 3V6, Canada