List of longest rivers of Canada
Nine rivers in this list cross international boundaries or form them. Four—the Yukon, Columbia, Porcupine, and Kootenay—begin in Canada and flow into the United States. Five—the Milk, Pend d'Oreille, Saint Lawrence, Red, and Saint John—begin in the United States and flow into Canada. Of these, the Milk and the Kootenay cross the international border twice, the Milk leaving and then re-entering the United States, the Kootenay leaving and then re-entering Canada. The drainage basins of these nine rivers extend into both countries; in addition, the drainage basins of six others—the Fraser, Assiniboine, South Saskatchewan, Saskatchewan, Nelson, and Winnipeg—extend into the United States even though their main stems flow entirely within Canada.
Fauna of Canada
Canada's rivers are famous for their annual runs of Atlantic salmon on the east coast and Pacific salmon on the west coast. Canada's many freshwater lakes and streams are home to rainbow trout, Arctic char, and brook trout. In the past, invasive species such as the lamprey and zebra mussel have threatened these native species, and while efforts to combat them have been made they still remain a hazard in some areas, and there are ongoing effort to prevent the spread of Asian carp from the United States.
There are also significant commercial fisheries of many salt-water species, including Atlantic cod, haddock and halibut, although some of these are in decline.