Planning and construction of the James Bay Hydroelectric project began in the early 1970s, when the effect of such projects on the physical and social environment was seldom considered. As the project matured, however, its unique and diverse environmental impacts came under intense scrutiny on both sides of the border. The first mega-scale hydro project to be built in the sub-Arctic, capable of generating as much electricity as fifteen nuclear power plants, its impact includes disruption of vast areas in an extremely fragile ecosystem as well as displacement of native peoples and the introduction of dangerous levels of mercury into their food supply. The debate over these complex environmental issues has been further complicated by political issues stemming from the importance of the project to the economic development of Quebec and the sale of at least ten percent of the electricity generated the United States. The contributors examine core issues of the controversy both in relation to James Bay and to other large hydroelectric projects, such as the Aswan dam in Egypt and the Three Gorges dam in China. Providing insights from an unusual variety of disciplines, the authors offer important considerations that must be taken into account as Quebec assesses additional phases of hydroelectric development of the watershed east of Hudson Bay. Contributors include Raymond B. Coppinger (Hampshire College), Bill Dale Roebuck (Dartmouth Medical School), Will Ryan (Hampshire College), Adrian Tanner (Memorial University), Stanley L. Warner (Hampshire College), Kessler E. Woodward (University of Alaska), and Oran R.Young (Dartmouth College). James F. Hornig is professor emeritus of chemistry and environmental studies, Dartmouth College.