Half of the ten provinces of Canada adjoin the Gulf: New Brunswick, Nova Scotia, Prince Edward Island, Newfoundland and Labrador, and Quebec.

The prevailing winds and currents push this ice towards the estuary, generally reaching east of Les Méchins around the end of December.

[15][16] Large marine mammals travel in all the seas of the earth, the research and observations of these giants concern fishermen and shipping industry, exercise a fascination and a keen interest for laymen and, subjects of endless studies for scientists from Quebec, Canada and around the world.

[citation needed] Download coordinates as: The Laurentian Channel is a feature of the floor of the Gulf that was formed during previous ice ages, when the Continental Shelf was eroded by the St. Lawrence River during the periods when the sea level plunged.

The Laurentian Channel is about 290 m (950 ft) deep and about 1,250 km (780 mi) long from the Continental Shelf to the mouth of the St. Lawrence River.

Deep waters with temperatures between 2 and 6.5 °C (36 and 44 °F) enter the Gulf at the continental slope and are slowly advected up the channel by estuariane circulation.

In its annual report on maritime traffic in Canada, the Federal Bureau of Statistics gives detailed annual statistics for the years 2019, 2020, 2021, 2022, 2023[52][53] Ports of the Gulf of St. Lawrence, on the Côte-Nord Shore: Blanc-Sablon, Harrington Harbor, Natashquan, Havre-Saint-Pierre, Mingan, Port-Menier (Anticosti Island), Cap-aux-Meules (Îles-de-la -Madeleine).

[52] The gulf has provided a historically important marine fishery for various First Nations that have lived on its shores for millennia and used its waters for transportation.