Great Lakes Basin Great Lakes Basin The Great Lakes Basin consists of the Great Lakes and the surrounding lands of the states of Illinois, Indiana, Michigan, Minnesota, New York, Ohio, Pennsylvania, and Wisconsin in the United States, and the province of Ontario in Canada, whose direct surface runoff and watersheds form a large drainage basin that feeds into the lakes. It is generally considered to also include a small area around and beyond Wolfe Island, Ontario, at the east end of Lake Ontario, which does not drain into the Great lakes, but into the Saint Lawrence River. The basin is home to 33
Great Lakes during the 1970s and 1980s, combined with successful salmonid stocking programs, have enabled the growth of a large recreational fishery. The last commercial fisherman left Milwaukee in 2011 because of overfishing and anthropogenic changes to the biosphere. Since the 19th century an estimated 160 new species have found their way into the Great Lakes ecosystem; many have become invasive; the overseas ship ballast and ship hull parasitism are causing severe economic and ecological impacts. According to the Inland Seas Education Association, on average a new species enters the Great Lakes every eight months. Introductions into the Great Lakes include the