Gulf of St Lawrence

St Lawrence, Gulf of
Gulf of St Lawrence, a large (250 000 km²), roughly triangular inland sea receiving on average 10 100 m³/s of fresh water from the ST LAWRENCE R at its northwest apex, is connected to the Atlantic by the Strait of Belle Isle at the northeast and CABOT STRAIT at the southeast corners. The deep Laurentian Channel extends from the St Lawrence estuary near TADOUSSAC, Qué, through the Cabot Strait to the edge of the Continental Shelf.

To the south lie the Iles de la MADELEINE and PRINCE EDWARD ISLAND, with the extensive Magdalen Shallows in between. North of the channel is Ile d' ANTICOSTI. Additional sources of fresh water include the SAGUENAY R and other north shore rivers, plus smaller amounts from New Brunswick and Newfoundland.

Much of the runoff is entrained in the Gaspé Current, flowing along the south shore of the estuary, out onto the Magdalen Shallows and eventually around the northern tip of CAPE BRETON ISLAND to form the Nova Scotian Current. The physical and biological effects of this fresh water are detectable as far away as the Gulf of Maine. Newfoundland Shelf water enters the gulf on the eastern side of Cabot Strait, drifts northeast along the west coast of Newfoundland and, coupled with a westerly drift along the north shore, completes a large counterclockwise gyre in the surface circulation.

Deep inflow of Atlantic water through Cabot Strait compensates for the net outflow of surface waters. Winter cooling and contributions from the Labrador Shelf via Belle Isle Strait result in significant ice cover (and associated navigational hazards) in the gulf for at least 3 months each winter. Economically the gulf, with the St Lawrence River and ST LAWRENCE SEAWAY, forms a transportation corridor to the heartland of industrial North America, carries away its waste products, and still yields about one-quarter of Canadian fish landings, both by weight and by value.

Before European contact, the gulf was frequented by nomadic Indian tribes, such as the MICMAC, who came seasonally to fish. The north shore was inhabited by INUIT, whose fierce opposition long prevented safe harbour. Jacques CARTIER explored the gulf in 1534, but was likely preceded in the area by BASQUE fishermen.

Author P.C. SMITH AND R.J. CONOVER

Links to Other Sites
Jacques Cartier
Watch the Heritage Minute about French explorer Jacques Cartier from the Historica-Dominion Institute. See also related online learning resources.

Maurice Lamontagne Institute
Learn about oceanographic research and management programs in the Gulf of St. Lawrence and northern Québec. A Fisheries and Oceans Canada website.

Gaspé
The official website of the City of Gaspé.

Anticosti Island
This website offers a detailed description of Anticosti Island. From the University of Laval.

Prince Edward Island Map and Satellite Image
A map and satellite image of Prince Edward Island and adjacent waterways. From geology.com.

The Memory Project: Gulf of St Lawrence
Listen to an interview with a seaman who served on a Canadian merchant ship that transported passengers and supplies in the Gulf of St Lawrence during the Second World War. Also check out related digitized artefacts and memorabilia. From the Historica-Dominion Institute.