533 Re-Establishing Lake Trout in the Laurentian Great Lakes: Past, Present, and Future Andrew M. Muir, Charles C. Krueger, and Michael J. Hansen Lake Trout (Salvelinus namaycush) were native to the Laurentian Great Lakes (hereafter, Great Lakes) and were widely distributed throughout lakes Superior, Michigan, Huron, and Ontario and the eastern basin of Lake Erie (fig. 1). Prior to European colonization, Lake Trout were an important resource for aboriginal peoples living around the Great Lakes (Bogue 2000). European colonization of the Laurentian Basin, during the eighteenth and nineteenth centuries, resulted in rapid expansion of Lake Trout fisheries. Colonization also brought about dramatic changes to landscapes, which, ultimately, had devastating and long-lasting effects on the ecology of watersheds. Forestry and shipping were two destructive practices that, when combined with rapidly expanding commercial fisheries, drove Lake Trout populations into decline by the early 1900s. Sea Lamprey (Petromyzon marinus), a voracious parasitic predator of fishes, invaded the Great Lakes via shipping channels and, ultimately, led to the demise of several Lake Trout populations, during the late nineteenth and early twentieth centuries. By the late 1950s, native Lake Trout were gone from lakes Ontario, Erie, and Michigan, nearly so from Lake Huron, and at low levels in most near-shore locations in Lake Superior. In response to these collapses, fishery management during the mid-1900s aimed to control fishing mortality, mitigate habitat loss and changes to native food webs, control non-native species invasions, conserve remnant stocks, and, ultimately, rehabilitate Great Lakes Lake Trout populations. Fisheries regulations, invasive species control programs, stocking, research, and assessment programs were among the tools used within a binational context. In this chapter, the history and current status of Lake Trout fisheries in the Great Lakes, their management, and efforts toward re-establishment is reviewed and future management is discussed within the context of historical lessons learned. Information from two previous reviews, one by Hansen (1999) published in the first edition of this book and a second by Krueger and Ebener (2004) published in Boreal Shield Watersheds: Lake Trout Ecosystems in a Changing Environment is consolidated and updated. Our specific objectives were to (1) review the history of Lake Trout fisheries and their management in the Great Lakes, (2) describe new and ongoing management actions to achieve Lake Trout rehabilitation goals, and (3) review lessons learned and describe emerging research themes that support Lake Trout rehabilitation.