Salmon- popular food

Salmon is the common name for several species of fish of the family Salmonidae. Several other fish in the family are called trout; the difference is often attributed to the migratory life of the salmon as compared to the residential behaviour of trout, a distinction that holds true for the Salmo genus. Salmon live in both the Atlantic (one migratory species Salmo salar) and Pacific Oceans, as well as the Great Lakes (approximately a dozen species of the genus Oncorhynchus).

Typically, salmon are anadromous: they are born in fresh water, migrate to the ocean, then return to fresh water to reproduce. However, there are rare species that can only survive in fresh water habitats. This is most likely due to the domestication of these certain species of Salmon. Folklore has it that the fish return to the exact spot where they were born to spawn, tracking studies have shown this to be true but the nature of how this memory works has long been debated.

Salmon as food

Salmon is a popular food. Consuming salmon is considered to be healthy due to the fish's high protein, high Omega-3 fatty acids, and high vitamin D content. Salmon is also a source of cholesterol, ranging 23–214 mg/100g depending on the species. According to reports in the journal Science, however, farmed salmon may contain high levels of dioxins. PCB (polychlorinated biphenyl) levels may be up to eight times higher in farmed salmon than in wild salmon. Omega-3 content may also be lower than in wild caught specimens, and in a different proportion to what is found naturally. Omega 3 comes in three types, ALA, DHA and EPA; wild salmon has traditionally been an important source of DHA and EPA, which are important for brain function and structure, among other things. This means that if the farmed salmon is fed on a meal which is partially grain then the amount of Omega 3 it contains will be present as ALA (alpha-linolenic acid). The body can itself convert ALA Omega 3 into DHA and EPA, but at a very inefficient rate (2–15%). Nonetheless, according to a 2006 study published in the Journal of the American Medical Association, the benefits of eating even farmed salmon still outweigh any risks imposed by contaminants . Type of Omega 3 present may not be a factor for other important health functions. A simple rule of thumb is that the vast majority of Atlantic salmon available on the world market are farmed (greater than 99%), whereas the majority of Pacific salmon are wild-caught (greater than 80%). Farmed Atlantic salmon outnumber wild Atlantic salmon 85 to 1.


Vitamin D is naturally produced by the human body when exposed to direct sunlight. Season, geographic latitude, time of day, cloud cover, smog, and sunscreen affect UV ray exposure and vitamin D synthesis in the skin, and it is important for individuals with limited sun exposure to include good sources of vitamin D in their diet.



Salmon flesh is generally orange to red in colour, although there are some examples of white fleshed wild salmon. The natural colour of salmon results from carotenoid pigments, largely astaxanthin but also canthaxanthin, in the flesh. Wild salmon get these carotenoids from eating krill and other tiny shellfish. Because consumers have shown a reluctance to purchase white fleshed salmon, astaxanthin (E161j), and very minutely canthaxanthin (E161g), are added as artificial colorants to the feed of farmed salmon because prepared diets do not naturally contain these pigments. In most cases the astaxanthin is made chemically; alternatively it is extracted from shrimp flour. Another possibility is the use of dried red yeast, which provides the same pigment.