Great Lakes passenger steamers Lakes) and a high-speed catamaran running between Milwaukee, Wisconsin and Muskegon, Michigan. An international ferry ran on Lake Ontario from Rochester, New York to Toronto from 2004 to 2005, but it was plagued with high operating costs and low demand. The privately owned company was taken over by the City of Rochester, and the ship was sold overseas where it operated across the Strait of Gibraltar. Cruise ship traffic on the Great Lakes increased in the early-21st century, with ships like the MS Hamburg, the MS Saint Laurent and the smaller ships of the Great Lakes Cruise Company offering multi-day
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