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
Rideau Canal canal to Kingston and out into Lake Ontario. The objective was to bypass the stretch of the St. Lawrence bordering New York; a route which would have left British supply ships vulnerable to an attack or a blockade of the St. Lawrence. The canal also served a commercial purpose. The Rideau Canal was easier to navigate than the St. Lawrence River because of the series of rapids between Montreal and Kingston. As a result, the Rideau Canal became a busy commercial artery from Montreal to the Great Lakes. However, by 1849, the rapids of the St. Lawrence had been tamed