Sustaining Lake Superior: An Extraordinary Lake in a Changing World by Nancy Langston (review)

Lake Superior is extraordinary. By surface area, it is the largest lake in the world, and it is bigger by volume than all of the other Great Lakes combined, containing a remarkable 12 percent of the world's fresh water. It is also an unusually cold lake, though it is one of the fastest-warming lakes in the world. As Nancy Langston shows in Sustaining Lake Superior, it embodies the environmental challenges to be faced as the climate continues to warm. Langston, a professor of environmental history and member of the Great Lakes Research Center at Michigan Technological University, is the perfect person to tell this story. She made her reputation as an environmental historian with two influential histories of conservation in the Pacific Northwest and then turned to the history of endocrine-disrupting toxics. Sustaining Lake Superior is a synthesis of these conservation and public health interests, one animated by Langston's own personal investment in a lake on whose shores she now lives.

Early chapters of Sustaining Lake Superior explore the lake's late nineteenth- and early twentieth-century histories of forest exploitation and mining. The region's forests were initially exploited for their white pines, but when those gave out and farming failed, a pulp and paper industry harvested the boreal forests on the Canadian shore. Pulp and paper brought industrial processing to the lakeshore, and regulators initially assumed that the massive lake could absorb pollution. But Langston shows that the limnological specifics of lake, in combination with the nature of the pollutants being discharged, made that model inadequate, particularly as lake pollutants became more toxic in the postwar years.

Lake Superior also was a major mining area, with the Lake Superior Iron Region producing 85 percent of the nation's iron ore by World War II. In three chapters at the heart of the book, Langston examines a shift after the war to the mining of a low-grade iron ore called taconite, which produced huge amounts of tailings. In 1947, the Reserve Mining Company proposed a massive mine in the eastern Mesabi Range that shipped taconite to a lakeside processing plant in Silver Bay, Minnesota. The company dumped its tailings into the lake, insisting that those "natural" wastes would remain in place. They did not. When it became clear that tailings were more mobile than the company cared to admit, and more toxic to boot, the federal government shut down the mine. A new era of federal environmental regulation beginning in the 1970s eventually undid a state-level conservation regime characterized by "cooperative pragmatism." Langston also includes a recent case study of a proposed but ultimately thwarted taconite mine just outside of the Bad River Reservation in Wisconsin, and the ways in which the mine threatened traditional Anishinaabe hunting, fishing, and gathering. One of Langston's central points is that pollution impacts that industrial interests saw as distant, and thus acceptable, were profoundly local and often dire for native peoples.

Over the last half-century, as a result of modern regimes of environmental regulation and U.S.-Canadian cooperation, Lake Superior experienced a recovery, and yet the lake has also faced more global challenges. In the 1990s, scientists noticed that the levels of toxaphene, a powerful pesticide used in cotton and soybean farming in the South, were rising in Lake Superior. This was strange, because the chemical had not been used in or near the lake for a long time. Eventually scientists figured out that legacy chemicals continued to be volatilized from southern landscapes and carried atmospherically to the north (they also arrived from China, Russia, and parts of Africa, where the chemical is still in use). Because Lake Superior is so cold, it became a sink for these and other mobile chemicals, which have biomagnified in fish as well as other birds and mammals. Langston shows that these global dynamics are making even remote boreal regions toxic in ways...