Sources des illustrations

Couverture recto : National Aeronautics Space Administration (NASA); couverture verso (haut), Josh Ingersoll, Lake Michigan Federation et (bas), Lauren Gordon, Morgan Edwards, Kyle Chandler, Environnement Canada; Figure 1, Adrian Melnyk et Don Boyes, département de géographie de l’Université de Toronto; page 17, NASA; Figure 2, Barry H. Rosen, Natural Resources Conservation Service, Watershed Science Institute, University of Vermont, Burlington; page 26, NASA; Figure 3, Jane C. Thapa, New York State Department of Health, Bureau of Water Supply Protection; Figure 4, Anne Pope, U.S. Environmental Protection Agency; Figure 5, Marc Deslauriers, Direction des données sur la pollution, Environnement Canada; Figure 6, a), OhioLINK Digital Media Center; b), Thomas Bridgeman, University of Toledo; c), Scott Higgins, University of Waterloo; d), Jeff Robinson, Service canadien de la faune; e), National Oceanic and Atmospheric Administration (NOAA) Great Lakes Environmental Research Laboratory; f), David Jude, University of Michigan; Figure 7, a), b) et d), Fred Snyder, Ohio Sea Grant Program; c), David Moore, University of Syracuse à Utica.