Atlantic salmon

The Atlantic salmon is an anadromous fish. They spend their first years in freshwater, and when they are big enough they undergo physiological and morphological changes, and migrate into seawter as a ’smolt’.

The smolt migrates from the rivers, throughout the fjords and into the open seas where they spend one to four years. In this period they grow fast, and when they are sexually mature, they migrate back to the river where they were born, to spawn.

The adult and sexually maturing salmon enters the rivers from early spring until late autumn. The spawning takes place from late autumn until mid winter. In Norway the salmon spawns within the same year they enter the river. In other areas (e.g. Scotland)…

Facts on Atlantic salmon

Latin name: Salmo salar
Other english names: Fry, parr, smolt, jacks, grilse
Family: Salmonidae
Maximum size: Up to 150 cm and 40 kg (males)
Life span: 2-8 years
Distribution: Lives in rivers on both sides of the Atlantic ocean, from Spain to Northwest Russia and from Maine to Northern Canada. A separate population lives in the Baltic. In the marine part of its lifecycle the salmon is spread over large parts of the Northern Atlantic ocean.
Spawning area: Rivers
Spawning time: October-January
Food: Juveniles in freshwater, mainly insects. As smolts and postsmolts in seawater, plancton and fish fry and as larger salmon, shrimp, pelagic fish as herring and lanternfish
Predators: Birds (e.g. Mergansers), coalfish, pollack and cod. In some areas sea mammals
Special features: The salmon is andromous, i.e. it is born and lives in freshwater for one to five years before it smoltifies and migrates into the ocean. It stays in the ocean for one to four years before it returns to the river to spawn.