Great Lakes Patrol assigned to operate against criminals who were ravaging the logging industry. These so called timber pirates conducted illegal cutting of timber on federal land and then smuggled the valuable commodity out of the area in order to sell it. The areas most affected were in the western Great Lakes region, along the coasts of Michigan, Wisconsin, Illinois and Minnesota. Much of these forested areas controlled by the government were reserved for the building of new warships. The illegal timber trade centered on Chicago and Milwaukee. It was nearly as violent as the alcohol trade, which was carried out over the
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