Illustration Credits

Front cover, National Aeronautics and Space Administration (NASA); back cover (top), Josh Ingersoll, Lake Michigan Federation and (bottom), Lauren Gordon, Morgan Edwards, Kyle Chandler, Environment Canada; Figure 1, Adrian Melnyk and Don Boyes, Department of Geography, University of 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, Pollution Data Branch, Environment Canada; Figure 6, (a), OhioLINK Digital Media Center; (b), Thomas Bridgeman, University of Toledo; (c), Scott Higgins, University of Waterloo; (d), Jeff Robinson, Canadian Wildlife Service; (e), National Oceanic and Atmospheric Administration (NOAA) Great Lakes Environmental Research Laboratory; (f), David Jude, University of Michigan; Figure 7, (a), (b) and (d), Fred Snyder, Ohio Sea Grant Program; (c), David Moore, University of Syracuse at Utica.