The broad Gulf of Saint Lawrence funnels imperceptibly from the Atlantic into Canada’s most important river, which remains tidal as far upstream as Quebec City. It is the largest estuary on earth, draining the Great Lakes Basin from the outflow of Lake Ontario some 800 miles inland. At the Gulf end, it is home to a known ten species of whales from giant blue whales to sperm humpback, fin, minke, right whales the small, porcelain-white belugas. Half of Canada’s ten provinces border the Gulf of Saint Lawrence: New Brunswick, Labrador and Newfoundland, Nova Scotia, Quebec and Prince Edward Island.