Salmon Salmon Recursive acronym Category="Cold water fish"Category="Salmon"Category="Salmonidae"
This article is about the fish. For other uses, see Salmon (disambiguation).

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Salmon is the common name for several species of fish of the Salmonidae family. Several other fishes in the family are called Trout. Salmon live in both the Atlantic and Pacific Oceans, as well as the Great Lakes and other land locked lakes. The Kamchatka Peninsula, in the Russian Far East, contains the world's greatest salmon sanctuary.

Salmon are anadromous: they are born in fresh water, migrate to the ocean, then return to fresh water to reproduce. Folklore has it that the fish return to the exact spot where they were born to spawn and modern research shows that usually at least 90% of the fish Spawning in a stream were born there. In Alaska, the crossing over to other streams allows salmon to populate new streams, such as those that emerge as a Glacier retreats. How they navigate is still a mystery, though their keen sense of smell may be involved. In all species of Pacific salmon, the mature individuals die within a few weeks of Spawning.

Coastal dwellers have long respected the salmon. Most peoples of the Northern Pacific shores had a ceremony to honor the first return of the year. For many centuries, people caught the salmon as they swam upriver. A famous spearfishing site on the Columbia River at Celilo Falls was inundated after great dams were built on the river. The Ainu, of northern Japan taught dogs how to catch salmon as they returned to their breeding grounds en masse. Now, salmon are caught in bays and near shore. Long drift net fisheries have been banned on the high seas except off the coast of Ireland.

Both Atlantic and Pacific Salmon are important to recreational fishing around the world.

In the southern hemisphere there is the Australian Salmon, which is a salt water species not related in any way to the salmonide. It is found along the southern coastline of Australia and Tasmania. Commonly caught there with large beach nets, its use as a commercial fish has been declining over the last 20 years.

Life History

[image] [image] The female salmon lays fertilized salmon eggs in stream bottom gravel nests called redds. These eggs usually range from an orange to red in color. The eggs hatch into alevin or sac fry. The fry quickly develop into parr with camouflaging vertical stripes. The parr stay for one to three years in their native stream before becoming smolts. The smolt body chemistry changes allowing them to live in salt water. As soon as they become covered with silvery scales they are called grilse. They migrate to the ocean where they will develop in about two to three years, (depending on the species) into mature salmon. After they develop, the adult salmon will return to its native stream, breed, spawn and die. When it spawns, depending on the Species, the salmon undergoes gruesome changes. Some grow a hump, others develop canine teeth and change colors, they rot while they are still alive. No one knows why they go back to the stream they were born in to die, but in order to complete their cycle they must die. Before they die the females release the eggs and the males fertilize them.

Salmon as Food

Salmon is a popular Food, and reasonably healthy due to its high Protein and Omega-3 fatty acids and its overall low Fat levels. According to reports by Science, however, farmed salmon may contain high levels of dioxins. PCB (Polychlorinated biphenyl) levels may also be up to 8 times higher in farmed salmon compared to wild salmon, and Omega-3 content may also be lower than wild caught species. But according to the British FSA (Food Standards Agency) the benefits of eating even farmed salmon still outweigh the risks. Conversely, salmon is generally one of the least tainted by Methylmercury of all fish.

A simple Rule of thumb is that the vast majority of Atlantic salmon available on the world market is farmed (greater than 99%), whereas the majority of Pacific salmon is wild-caught (greater than 80%).

Salmon is a white-flesh fish. The natural color of salmon results from carotenoids - Astaxanthin and to a lesser degree, Canthaxanthin - in the fish flesh. Wild salmon get these carotenoids from eating Krill and other tiny Shellfish. Farm salmon get them in their feed, along with other essential nutrients. Astaxanthin is a potent Antioxidant that also stimulates fish nervous systems and improves fertility and growth.

Canned salmon in the U.S. is always wild Pacific catch. Smoked salmon is another popular preparation method, and can either be hot or cold smoked. Lox can refer either to cold smoked salmon, or to salmon cured in a brine solution (also called Gravlax).

Raw salmon meat may contain anisakidae, marine parasites that cause Anisakiasis. Before the availability of Refrigeration, Japanese did not consume raw salmon. Salmon and salmon roes were not used to make Sashimi (raw fish) and Sushi until recently.

Aquaculture

Salmon is the third largest seafood product raised on fish farms, with shrimp being the second and carps being by far the largest product. Raising salmon on farms decreases the demand for wild salmon but paradoxically increases the demand for other wild fish. Salmon are carnivorous and are currently fed a meal produced from catching other wild fish, so as the number of farmed salmon increase, the demand for other fish to feed the salmon increases. Work continues on substituting vegetable proteins for animal proteins in the salmon diet. Most of the farms in Alaska have a special process for breeding the salmon in the farm. The salmon are born inside a stream in the farm and are bred in special waters until they are old enough to become independent. They are released into the ocean were they are free to live and develop fully until it is time for them to die. When they sense they are going to spawn they immediately return to their stream of birth, in this case they return to the farm where they were born, to breed and then they die. The farmers allow them to release some of their eggs and some of the other eggs are stripped of to produce the eggs that are sold around the world.

Species

The various species of salmon have many names.

Atlantic Ocean species

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Pacific Ocean species

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Pacific Ocean Salmon
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Sockeye Salmon
Scientific classification
Kingdom:Animalia
Phylum:Chordata
Class:Actinopterygii
Order:Salmoniformes
Family:Salmonidae
Genus:Oncorhynchus
Species
O. nerka
O. tshawytscha
O. gorbuscha
O. keta
O. kisutch
O. masou

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External links

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Wikibooks Cookbook has more about this subject:
Salmon

Further reading