II.

Lake Shipping

The Great Lakes, interconnected by rivers, straits, and canals, together form one of the world's busiest shipping arteries. They are linked with the Atlantic Ocean by the St Lawrence River, and, since the completion in 1959 of the St Lawrence Seaway, they have been open to medium-sized ocean-going vessels, allowing them to travel as far west as Duluth, Minnesota. In addition, Lake Erie is connected with the Atlantic by way of the Erie Canal and the Hudson River, and Lake Michigan is linked with the Gulf of Mexico via the Illinois Waterway and the Mississippi River. Interlake waterways include the Welland Ship Canal, which bypasses Niagara Falls to link Lakes Ontario and Erie, and the Sault Sainte Marie Canals, which permit navigation between Lakes Huron and Superior.

Specially designed long, narrow vessels, called lakers, handle most of the freight carried on the lakes, which are closed to shipping by ice during the winter. The principal cargoes transported are iron ore and grain. Although iron and steel production have decreased in recent years, iron ore is still the largest single cargo shipped on the lakes; it is transported from the Lake Superior region to ports on the southern shore of Lake Erie, from which it is sent to the steel mills of Ohio, Pennsylvania, and Indiana. Vast quantities of grain produced in the upper Midwest of the United States and in the Prairie provinces of Canada are transported via the lakes, principally from Thunder Bay, Ontario, to processing centres such as Buffalo, New York, on Lake Erie, and also abroad. Coal, limestone, and manufactured goods are also shipped on the lakes. Most of the cargo is carried from west to east. About 10-20 per cent of the freight shipped from Great Lakes’ ports passes through the St Lawrence Seaway.