Great Lakes are estimated at 900 trillion. The influx of parasitic lamprey populations after the development of the Erie Canal and the much later Welland Canal led to the two federal governments of the US and Canada working on joint proposals to control it. By the mid-1950s, the lake trout populations of Lakes Michigan and Huron were reduced, with the lamprey deemed largely to blame. This led to the launch of the bi-national Great Lakes Fishery Commission. "The Great Lakes: An Environmental Atlas and Resource Book" (1972) noted: "Only pockets remain of the once large commercial fishery." But, water quality improvements realized
Great Lakes Greyhound Lines new subsidiary, named as the Great Lakes Greyhound Lines, which in 1941 took over the EMM. In 1941, when the Great Lakes GL came into existence, The Greyhound Corporation merged the Ohio GL into the new Great Lakes GL. The Ohio GL had run between Detroit and Louisville (in Kentucky) via Toledo, Dayton, and Cincinnati (all three in Ohio), plus along a detached route between Evansville and Indianapolis (both in Indiana). [The route segment between Louisville and Cincinnati had come from the Southland Transportation Company, which Harris Spearin, with the backing and financing of Wickman in Minnesota, had founded in