Fast Facts: Salmon

Name: Atlantic or Pacific salmon
Descriptive name: Salmonid
Family name: Salmonidae
Pacific salmon species name: Oncorhynchus
Atlantic salmon species name: Salmo
Average weight: 7 kg
Average wingspan: 127 to 173 cm

Did you know?

Many salmon are anadromous — this means they live in the saltwater of the ocean but return to freshwater, their native river, to spawn.

Physiology

The salmon is part of a family of fish called Salmonidae, which includes trout and char. The fish has soft fin rays, a short dorsal fin, a fatty (adipose) fin, and teeth in its jaws. A young salmon has a splotched colour on its sides for the first three years of its life, and then its scales turn to silver when it leaves for the ocean. Upon returning to its native river to reproduce, the salmon turns black. The head of a female salmon is streamlined throughout its lifetime. A male, on the other hand, develops a hook, called a kype, in its jaw before reproducing.

Habitats/Behaviours

A young salmon will stay in the river where it was born for the first one to three years of its life. It will then leave for the ocean and return only to spawn. Adult salmon are excellent jumpers and can ascend rapids to reach freshwater. They have been known to cover over 3,200 kilometres to reach their spawning ground. In the '70s, there were 900,000 Atlantic salmon returning to spawn; today, there are only 100,000 that return. Atlantic salmon are able to spawn more than once, but some die of exhaustion after breeding. Pacific salmon reproduce only once and die shortly after.

There are five species of Pacific salmon on the West Coast: the kokanee, which spends its whole life in freshwater, the chinook, which grows as long as one metre, the pink Pacific salmon, known as the smallest Pacific salmon, the chum and the coho salmon.

Range

Atlantic salmon can be found in Quebec and the Maritimes, while Pacific salmon are found on the West Coast. Salmon aquaculture is big business in Canada – when humans raise the fish in an aquatic farm.  Currently, one out of every two salmonids are farmed. In 2001, British Columbia's production of farmed salmon was 95,000 tonnes. This was 65 percent of Canada's total farmed salmon production, and five percent of the world's total. In the case of wild salmon, the Atlantic salmon, the sockeye salmon and the coho are listed as threatened or endangered species in Canada.

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