1. Department of Integrative Biology; University of Guelph; Guelph Ontario N1G 2W1 Canada
2. Center for Limnology; University of Wisconsin-Madison; Madison Wisconsin 53706 USA
3. Great Lakes Institute for Environmental Research; University of Windsor; Windsor Ontario N9B 3P4 Canada
4. Great Lakes Fisheries Commission; Ann Arbor Michigan 48105 USA
5. Harkness Laboratory of Fisheries Research; Aquatic Research and Monitoring Section; Ontario Ministry of Natural Resources; Peterborough Ontario K9J 7B8 Canada
6. School of Environmental Sciences; University of Guelph; Guelph Ontario N1G 2W1 Canada