Saint Lawrence River - Great Rivers Of North America

The Saint Lawrence River passing under a bridge in the city of Montreal, Quebec, Canada.

5. Description

The Saint Lawrence River and Seaway is a major hydrographical system of North America. It begins at the North River in Minnesota, which flows into Lake Superior through the Cabot Strait and finally empties into the Atlantic Ocean east of Canada. The river system is of crucial hydrologic, geographic, and economic importance both to the United States and Canada. It can be divided into three broad sections: Upriver is the Great Lakes region with narrow streams linking the lakes. From the center, the River flows east to Lake Ontario and out from its eastern section to the Ile d’Orleans just downstream from Quebec. Now the River starts to broaden out and flows into the St. Lawrence estuary. The river then merges with the waters off Anticosti Island and empties into the Gulf of St. Lawrence. The St. Lawrence River is embedded in an ancient geologic depression and drains the heart of North America. It is at once an international, a multi-provincial and intra-Quebec system and an important water, fishing and navigational resource for the local populations. The landscape throughout the river’s length of 2,500 miles (4,000 kilometers) is of great natural beauty.

4. Historical Role

The first European explorer able to sail up the St. Lawrence River from the Gulf of St. Lawrence was Jacques Cartier in the 16th Century. As he had arrived at the Gulf on the feast day of St.Lawrence, he named the Gulf after the saint. At the time the lands along the river were occupied by the St. Lawrence Iroquoians. The earliest regular Europeans were the Basques from Spain and France who sailed in pursuit of whales, and they traded with Native Americans and set up settlements in eastern Canada and deep into St. Lawrence River. The St.Lawrence River as means of exploring the interior of the continent was pioneered by Samuel de Champlain. Control of the River was crucial to the British to capture New France in the American theater of the Seven Years’ War. The British also used the river to counter the French siege of Quebec. The St.Lawrence River was for a long time navigable only as far as Montreal. The Lachine Rapids after Montreal were practically impassable. It was only in 1825 that Lachine Canal opened. Thereafter, ships could sail through the rapids to the westernmost reaches of the St. Lawrence system. Almost the entire River system was the scene of some intense fighting in the Second World War, as German U-boats encroached into the Canadian waters.

3. Modern Significance

In the early Twentieth Century, vast amounts iron ore were discovered in Quebec and Labrador, which was needed by steel mills in the United States. Canada was the first to realize the importance of a seaway through which ships could sail in from the Atlantic creating a navigable sea route to Lake Superior. Work began on the Canadian-U.S. joint venture in 1954 and the Seaway was completed in 1959. The Seaway, with its extensive system of canals and locks, has had a significant economic impact on both stakeholder countries. The largest commodity transported is grain, which is shipped both from Canadian prairies and the American Midwest at considerable lower costs. A major portion of the shipping in the Seaway is by vessels known as lakers. Lakers ply a two-way trade within North America and the world. Lakers may pick up cargo in the Great Lakes and transport it for world markets. On their return journey, they can Canadian iron ore. The third-largest commodity shipped through the Seaway is coal from U.S. mines to Canadian steel mills. Imported iron and steel are the other important commodities used both by the U.S. and Canada.

2. Habitat and Biodiversity

The biodiversity around the St.Lawrence River System has remained unchanged for centuries though it has been influenced by humans. Ecologically, there are some regional distinctions between the upper and lower sectors of the System, between the depths and water surfaces and between the center of the river course and the banks. Naturally, aquatic life represents the predominant animal species of the system. The varieties of fish include sturgeon, smelt and herring. The Beluga (White Whale) still rules the Gulf of St. Lawrence. Also abundant are a variety of mollusks, including the soft-shell clam. Migration of birds such as ducks, bustards and geese are seen throughout the System. The birds come to the sandy shores and river reefs for seasonal food. Vegetation from Lake Erie through to the Gulf consists of deciduous, coniferous and mixed forests and the open taiga. The St. Lawrence River also has the characteristic river greenery like sandbank grasses and salt-tolerant plants, which grow from the middle estuary onward.

1. Environmental Threats and Territorial Disputes

Some of the greatest environmental threats in the Saint Lawrence River system are posed to its whales. Burgeoning metropolises along its banks, the ships that traverse its waters, and climate change alike pose threats to these whales and the balance of the ecosystems they live in. Among the resident whales of the St. Lawrence, the Blue Whale, Fin Whale, and Northern Right Whale are classified as "endangered", the Beluga whale is "near threatened", and the Sperm whale is "vulnerable", as per the International Union for the Conservation of Nature's Red List of Threatened Species.


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