1. Department of Environmental Biology, University of Guelph, Bovey Building, Guelph, Ontario N1G 2W1, Canada, Carleton University, Ottawa, Ontario K15 5B6, Canada, Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario M5S 3H6, Canada, National Environmental Research Institute of Denmark, P.O. Box 358, Frederiksborgvej 399, DK-4000, Roskilde, Denmark, United States Fish and Wildlife Service, 1011 East Tudor Road, Anchorage, Alaska 99503, Canadian Wildlife Service,...