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The Atlantic salmon, Salmo salar, is a fish in the family Salmonidae, which is found in the northern Atlantic Ocean and in rivers that flow into the north Atlantic and, due to human introduction, the north Pacific.
It is also commercially known as bay salmon, black salmon, caplin-scull salmon, fiddler, grilse, grilt, kelt, landlocked salmon, ouananiche, outside salmon, parr, Sebago salmon, silver salmon, slink, smolt, spring salmon, or winnish.
- 1 Life stages
- 2 Nomenclature
- 3 Physiology
- 4 Distribution and habitat
- 5 Diet
- 6 Behaviour
- 7 Breeding
- 8 Hybridization
- 9 Aquaculture
- 10 Human impact
- 11 Recovery
- 12 Beaver impact
- 13 Legislation
- 14 NASCO
- 15 Sustainable consumption
- 16 See also
- 17 Notes
- 18 References
- 19 External links
Life stages[edit source | edit]
Most Atlantic salmon follow an anadromous fish migration pattern, in that they undergo their greatest feeding and growth in salt water; however, adults return to spawn in native freshwater streams where the eggs hatch and juveniles grow through several distinct stages.
Atlantic salmon do not require salt water. Numerous examples of fully freshwater (i.e., "landlocked") populations of the species exist throughout the Northern Hemisphere. In North America, the landlocked strains are frequently known as ouananiche.
Freshwater phase[edit source | edit]
The freshwater phases of Atlantic salmon vary between one and eight years, variably according to river location. While the young in southern rivers, such as those to the English Channel, are only one year old when they leave, those further north, such as in Scottish rivers, can be over four years old, and in Ungava Bay, northern Quebec, smolts as old as eight years have been encountered. The average age correlates to temperature exceeding 7°C (45°F).
The first phase is the alevin stage, when the fish stay in the breeding ground and use the remaining nutrients in their yolk sacs. During this developmental stage, their young gills develop and they become active hunters. Next is the fry stage, where the fish grow and subsequently leave the breeding ground in search of food. During this time, they move to areas with higher prey concentration. The final freshwater stage is when they develop into parr, in which they prepare for the trek to the Atlantic Ocean.
Saltwater phases[edit source | edit]
When parr develop into smolt, they begin the trip to the ocean, which predominantly happens between March and June. Migration allows acclimation to the changing salinity. Once ready, young smolt leave, preferring an ebb tide.
Having left their natal streams, they experience a period of rapid growth during the one to four years they live in the ocean. Typically, Atlantic salmon migrate from their home streams to an area on the continental plate off West Greenland. During this time, they face predation from humans, seals, Greenland sharks, skate, cod, and halibut. Some dolphins have been noticed playing with dead salmon, but it is still unclear whether they consume them.
Once large enough, Atlantic salmon change into the grilse phase, when they become ready to return to the same freshwater tributary they departed from as smolts. After returning to their natal streams, the salmon will cease eating altogether prior to spawning. Although largely unknown, odor – the exact chemical signature of that stream – may play an important role in how salmon return to the area where they hatched. Once heavier than about 250 g, the fish no longer become prey for birds and many fish, although seals do prey upon them. Grey and common seals commonly eat Atlantic salmon. Survivability to this stage has been estimated at between 14 and 53%.
Nomenclature[edit source | edit]
The name, Salmo salar, is from the Latin salmo, meaning salmon, and salar, meaning leaper, according to M. Barton, but more likely meaning "resident of salt water". Lewis and Short's Latin Dictionary (Clarendon Press, Oxford, 1879) translates salar as a kind of t