Contents for Atlantic salmon

Scientific name: Salmo salar.

Distribution: North Atlantic Ocean: temperate and arctic zones in northern hemisphere. In the western Atlantic, it ranges from western Greenland and the coastal drainages of Quebec, Canada, to Connecticut, USA. Landlocked stocks are present in North America. In the eastern Atlantic, it ranges from the White and Barents Sea basins through northeastern Europe to the Baltic and North Sea basins, including Iceland. Introduced to New Zealand, Chile, southern Argentina and Australia.

Biology: Amphihaline species, spending most of its life in freshwater. Some landlocked populations exist. Found in all rivers where temperature rises above 10° C for about 3 months per year and does not exceed 20° C for more than a few weeks in summer (preferred temperatures 4-12°C). Juveniles may live in cold lakes in northern Europe. Parr (i.e. juveniles) are territorial and are found in the upper reaches of rivers and streams, in riffle areas with strong current and rough gravel bottoms. During winter, parr seek refuge in small spaces or under stones during the day. Young remain in freshwater for 1 to 6 years, then migrate to coastal marine waters or even to open oceans where they remain for 1 to 4 years before returning to freshwater for spawning. Adults inhabit cooler waters with strong to moderate flow. The Atlantic salmon is reported to live up to 10 years, but most individuals only reach 4-6 years. Juveniles feed mainly on aquatic insects, mollusks, crustaceans and fish; adults at sea feed on squids, shrimps, and fish. Most populations depend mostly or exclusively on stocking due to degradations of environmental conditions. Fishing pressure on wild stocks has decreased due to intensive farming but other problems have increased. Farmed salmons escape in large numbers and move to any river and hybridize with wild stocks.