|Cladistically included but traditionally excluded taxa|
Salmon /ˈsæmən/ is the common name for several species of ray-finned fish in the family Salmonidae. Other fish in the same family include trout, char, grayling and whitefish. Salmon are native to tributaries of the North Atlantic (genus Salmo) and Pacific Ocean (genus Oncorhynchus). Many species of salmon have been introduced into non-native environments such as the Great Lakes of North America and Patagonia in South America. Salmon are intensively farmed in many parts of the world.
Typically, salmon are anadromous: they hatch in fresh water, migrate to the ocean, then return to fresh water to reproduce. However, populations of several species are restricted to fresh water through their lives. Folklore has it that the fish return to the exact spot where they hatched to spawn. Tracking studies have shown this to be mostly true. A portion of a returning salmon run may stray and spawn in different freshwater systems; the percent of straying depends on the species of salmon. Homing behavior has been shown to depend on olfactory memory. Salmon date back to the Neogene.
The term "salmon" comes from the Latin salmo, which in turn might have originated from salire, meaning "to leap". The nine commercially important species of salmon occur in two genera. The genus Salmo contains the Atlantic salmon, found in the north Atlantic, as well as many species commonly named trout. The genus Oncorhynchus contains eight species which occur naturally only in the North Pacific. As a group, these are known as Pacific salmon. Chinook salmon have been introduced in New Zealand and Patagonia. Coho, freshwater sockeye, and Atlantic salmon have been established in Patagonia, as well.
† Both the Salmo and Oncorhynchus genera also contain a number of species referred to as trout. Within Salmo, additional minor taxa have been called salmon in English, i.e. the Adriatic salmon (Salmo obtusirostris) and Black Sea salmon (Salmo labrax). The steelhead anadromous form of the rainbow trout migrates to sea, but it is not termed "salmon".
Also a number of other species have common names which refer to them as being salmon. Of those listed below, the Danube salmon or huchen is a large freshwater salmonid related to the salmon above, but others are marine fishes of the unrelated Perciformes order:
Eosalmo driftwoodensis, the oldest known salmon in the fossil record, helps scientists figure how the different species of salmon diverged from a common ancestor. The British Columbia salmon fossil provides evidence that the divergence between Pacific and Atlantic salmon had not yet occurred 40 million years ago. Both the fossil record and analysis of mitochondrial DNA suggest the divergence occurred by 10 to 20 million years ago. This independent evidence from DNA analysis and the fossil record rejects the glacial theory of salmon divergence.
Salmon eggs are laid in freshwater streams typically at high latitudes. The eggs hatch into alevin or sac fry. The fry quickly develop into parr with camouflaging vertical stripes. The parr stay for six months to three years in their natal stream before becoming smolts, which are distinguished by their bright, silvery colour with scales that are easily rubbed off. Only 10% of all salmon eggs are estimated to survive to this stage. The smolt body chemistry changes, allowing them to live in salt water. While a few species of salmon remain in fresh water throughout their life cycle, the majority are anadromous and migrate to the ocean for maturation: in these species, smolts spend a portion of their out-migration time in brackish water, where their body chemistry becomes accustomed to osmoregulation in the ocean.
The salmon spend about one to five years (depending on the species) in the open ocean, where they gradually become sexually mature. The adult salmon then return primarily to their natal streams to spawn. Atlantic salmon spend between one and four years at sea. When a fish returns after just one year's sea feeding, it is called a grilse in Canada, Britain, and Ireland. Grilse may be present at spawning, and go unnoticed by large males, releasing their own sperm on the eggs. Prior to spawning, depending on the species, salmon undergo changes. They may grow a hump, develop canine-like teeth, or develop a kype (a pronounced curvature of the jaws in male salmon). All change from the silvery blue of a fresh-run fish from the sea to a darker colour. Salmon can make amazing journeys, sometimes moving hundreds of miles upstream against strong currents and rapids to reproduce. Chinook and sockeye salmon from central Idaho, for example, travel over 1,400 km (900 mi) and climb nearly 2,100 m (7,000 ft) from the Pacific Ocean as they return to spawn. Condition tends to deteriorate the longer the fish remain in fresh water, and they then deteriorate further after they spawn, when they are known as kelts. In all species of Pacific salmon, the mature individuals die within a few days or weeks of spawning, a trait known as semelparity. Between 2 and 4% of Atlantic salmon kelts survive to spawn again, all females. However, even in those species of salmon that may survive to spawn more than once (iteroparity), postspawning mortality is quite high (perhaps as high as 40 to 50%).
To lay her roe, the female salmon uses her tail (caudal fin), to create a low-pressure zone, lifting gravel to be swept downstream, excavating a shallow depression, called a redd. The redd may sometimes contain 5,000 eggs covering 2.8 m2 (30 sq ft). The eggs usually range from orange to red. One or more males approach the female in her redd, depositing sperm, or milt, over the roe. The female then covers the eggs by disturbing the gravel at the upstream edge of the depression before moving on to make another redd. The female may make as many as seven redds before her supply of eggs is exhausted.
Each year, the fish experiences a period of rapid growth, often in summer, and one of slower growth, normally in winter. This results in ring formation around an earbone called the otolith (annuli), analogous to the growth rings visible in a tree trunk. Freshwater growth shows as densely crowded rings, sea growth as widely spaced rings; spawning is marked by significant erosion as body mass is converted into eggs and milt.
Freshwater streams and estuaries provide important habitat for many salmon species. They feed on terrestrial and aquatic insects, amphipods, and other crustaceans while young, and primarily on other fish when older. Eggs are laid in deeper water with larger gravel, and need cool water and good water flow (to supply oxygen) to the developing embryos. Mortality of salmon in the early life stages is usually high due to natural predation and human-induced changes in habitat, such as siltation, high water temperatures, low oxygen concentration, loss of stream cover, and reductions in river flow. Estuaries and their associated wetlands provide vital nursery areas for the salmon prior to their departure to the open ocean. Wetlands not only help buffer the estuary from silt and pollutants, but also provide important feeding and hiding areas.
Salmon not killed by other means show greatly accelerated deterioration (phenoptosis, or "programmed aging") at the end of their lives. Their bodies rapidly deteriorate right after they spawn as a result of the release of massive amounts of corticosteroids.
In the Pacific Northwest and Alaska, salmon are keystone species, supporting wildlife such as birds, bears and otters. The bodies of salmon represent a transfer of nutrients from the ocean, rich in nitrogen, sulfur, carbon and phosphorus, to the forest ecosystem.
Grizzly bears function as ecosystem engineers, capturing salmon and carrying them into adjacent wooded areas. There they deposit nutrient-rich urine and feces and partially eaten carcasses. Bears are estimated to leave up to half the salmon they harvest on the forest floor, in densities that can reach 4,000 kilograms per hectare, providing as much as 24% of the total nitrogen available to the riparian woodlands. The foliage of spruce trees up to 500 m (1,600 ft) from a stream where grizzlies fish salmon have been found to contain nitrogen originating from fished salmon.
Beavers also function as ecosystem engineers; in the process of clear-cutting and damming, beavers alter their ecosystems extensively. Beaver ponds can provide critical habitat for juvenile salmon. An example of this was seen in the years following 1818 in the Columbia River Basin. In 1818, the British government made an agreement with the U.S. government to allow U.S. citizens access to the Columbia catchment (see Treaty of 1818). At the time, the Hudson's Bay Company sent word to trappers to extirpate all furbearers from the area in an effort to make the area less attractive to U.S. fur traders. In response to the elimination of beavers from large parts of the river system, salmon runs plummeted, even in the absence of many of the factors usually associated with the demise of salmon runs. Salmon recruitment can be affected by beavers' dams because dams can:
Beavers' dams are able to nurture salmon juveniles in estuarine tidal marshes where the salinity is less than 10 ppm. Beavers build small dams of generally less than 60 cm (2 ft) high in channels in the myrtle zone. These dams can be overtopped at high tide and hold water at low tide. This provides refuges for juvenile salmon so they do not have to swim into large channels where they are subject to predation.
It has been discovered that rivers which have seen a decline or disappearance of anadromous lampreys, loss of the lampreys also affects the salmon in a negative way. Like salmon, anadromous lampreys stop feeding and die after spawning, and their decomposing bodies release nutrients into the stream. Also, along with species like steelhead redds and Sacramento sucker, lampreys clean the gravel in the rivers during spawning. Their larvae, called ammocoetes, are filter feeders which contribute to the health of the waters. They are also a food source for the young salmon, and being fattier and oilier, it is assumed predators prefer them over salmon offspring, taking off some of the predation pressure on smolts. Adult lampreys are also the preferred prey of seals and sea lions, which can eat 30 lampreys to every salmon, allowing more adult salmon to enter the rivers to spawn without being eaten by the marine mammals.
According to Canadian biologist Dorothy Kieser, the myxozoan parasite Henneguya salminicola is commonly found in the flesh of salmonids. It has been recorded in the field samples of salmon returning to the Haida Gwaii Islands. The fish responds by walling off the parasitic infection into a number of cysts that contain milky fluid. This fluid is an accumulation of a large number of parasites.
Henneguya and other parasites in the myxosporean group have complex life cycles, where the salmon is one of two hosts. The fish releases the spores after spawning. In the Henneguya case, the spores enter a second host, most likely an invertebrate, in the spawning stream. When juvenile salmon migrate to the Pacific Ocean, the second host releases a stage infective to salmon. The parasite is then carried in the salmon until the next spawning cycle. The myxosporean parasite that causes whirling disease in trout has a similar life cycle. However, as opposed to whirling disease, the Henneguya infestation does not appear to cause disease in the host salmon—even heavily infected fish tend to return to spawn successfully.
According to Dr. Kieser, a lot of work on Henneguya salminicola was done by scientists at the Pacific Biological Station in Nanaimo in the mid-1980s, in particular, an overview report which states, "the fish that have the longest fresh water residence time as juveniles have the most noticeable infections. Hence in order of prevalence coho are most infected followed by sockeye, chinook, chum and pink." As well, the report says, at the time the studies were conducted, stocks from the middle and upper reaches of large river systems in British Columbia such as Fraser, Skeena, Nass and from mainland coastal streams in the southern half of B.C., "are more likely to have a low prevalence of infection." The report also states, "It should be stressed that Henneguya, economically deleterious though it is, is harmless from the view of public health. It is strictly a fish parasite that cannot live in or affect warm blooded animals, including man".
According to Klaus Schallie, Molluscan Shellfish Program Specialist with the Canadian Food Inspection Agency, "Henneguya salminicola is found in southern B.C. also and in all species of salmon. I have previously examined smoked chum salmon sides that were riddled with cysts and some sockeye runs in Barkley Sound (southern B.C., west coast of Vancouver Island) are noted for their high incidence of infestation."
Sea lice, particularly Lepeophtheirus salmonis and various Caligus species, including C. clemensi and C. rogercresseyi, can cause deadly infestations of both farm-grown and wild salmon. Sea lice are ectoparasites which feed on mucus, blood, and skin, and migrate and latch onto the skin of wild salmon during free-swimming, planktonic nauplii and copepodid larval stages, which can persist for several days. Large numbers of highly populated, open-net salmon farms can create exceptionally large concentrations of sea lice; when exposed in river estuaries containing large numbers of open-net farms, many young wild salmon are infected, and do not survive as a result. Adult salmon may survive otherwise critical numbers of sea lice, but small, thin-skinned juvenile salmon migrating to sea are highly vulnerable. On the Pacific coast of Canada, the louse-induced mortality of pink salmon in some regions is commonly over 80%.
The risk of injury caused by underwater pile driving has been studied by Dr. Halvorsen and her co-workers. The study concluded that the fish are at risk of injury if the cumulative sound exposure level exceeds 210 dB relative to 1 μPa2 s.
As can be seen from the production chart at the left, the global capture reported by different countries to the FAO of commercial wild salmon has remained fairly steady since 1990 at about one million tonnes per year. This is in contrast to farmed salmon (below) which has increased in the same period from about 0.6 million tonnes to well over two million tonnes.
Nearly all captured wild salmon are Pacific salmon. The capture of wild Atlantic salmon has always been relatively small, and has declined steadily since 1990. In 2011 only 2,500 tonnes were reported. In contrast about half of all farmed salmon are Atlantic salmon.
Recreational salmon fishing can be a technically demanding kind of sport fishing, not necessarily congenial for beginning fishermen. A conflict exists between commercial fishermen and recreational fishermen for the right to salmon stock resources. Commercial fishing in estuaries and coastal areas is often restricted so enough salmon can return to their natal rivers where they can spawn and be available for sport fishing. On parts of the North American west coast sport salmon fishing completely replaces inshore commercial fishing. The commercial value of a salmon can be several times less than the value of the same fish caught by a sport fisherman. This is "a powerful economic argument for allocating stock resources preferentially to sport fishing."
Salmon aquaculture is a major contributor to the world production of farmed finfish, representing about US$10 billion annually. Other commonly cultured fish species include tilapia, catfish, sea bass, carp and bream. Salmon farming is significant in Chile, Norway, Scotland, Canada and the Faroe Islands; it is the source for most salmon consumed in the United States and Europe. Atlantic salmon are also, in very small volumes, farmed in Russia and Tasmania, Australia.
Salmon are carnivorous. They are fed a meal produced from catching other wild fish and other marine organisms. Salmon farming leads to a high demand for wild forage fish. Salmon require large nutritional intakes of protein, and farmed salmon consume more fish than they generate as a final product. On a dry weight basis, 2–4 kg of wild-caught fish are needed to produce one kg of salmon. As the salmon farming industry expands, it requires more wild forage fish for feed, at a time when 75% of the world's monitored fisheries are already near to or have exceeded their maximum sustainable yield. The industrial-scale extraction of wild forage fish for salmon farming affects the survivability of the wild predator fish which rely on them for food.
Work continues on substituting vegetable proteins for animal proteins in the salmon diet. This substitution results in lower levels of the highly valued omega-3 fatty acid content in the farmed product.
Another form of salmon production, which is safer but less controllable, is to raise salmon in hatcheries until they are old enough to become independent. They are released into rivers in an attempt to increase the salmon population. This system is referred to as ranching. It was very common in countries such as Sweden, before the Norwegians developed salmon farming, but is seldom done by private companies. As anyone may catch the salmon when they return to spawn, a company is limited in benefiting financially from their investment.
Because of this, the ranching method has mainly been used by various public authorities and nonprofit groups, such as the Cook Inlet Aquaculture Association, as a way to increase salmon populations in situations where they have declined due to overharvesting, construction of dams, and habitat destruction or fragmentation. Negative consequences to this sort of population manipulation include genetic "dilution" of the wild stocks. Many jurisdictions are now beginning to discourage supplemental fish planting in favour of harvest controls, and habitat improvement and protection.
A variant method of fish stocking, called ocean ranching, is under development in Alaska. There, the young salmon are released into the ocean far from any wild salmon streams. When it is time for them to spawn, they return to where they were released, where fishermen can catch them.
An alternative method to hatcheries is to use spawning channels. These are artificial streams, usually parallel to an existing stream, with concrete or rip-rap sides and gravel bottoms. Water from the adjacent stream is piped into the top of the channel, sometimes via a header pond, to settle out sediment. Spawning success is often much better in channels than in adjacent streams due to the control of floods, which in some years can wash out the natural redds. Because of the lack of floods, spawning channels must sometimes be cleaned out to remove accumulated sediment. The same floods that destroy natural redds also clean the regular streams. Spawning channels preserve the natural selection of natural streams, as there is no benefit, as in hatcheries, to use prophylactic chemicals to control diseases.
One proposed alternative to the use of wild-caught fish as feed for the salmon, is the use of soy-based products. This should be better for the local environment of the fish farm, but producing soy beans has a high environmental cost for the producing region. The fish omega-3 fatty acid content would be reduced compared to fish-fed salmon.
Another possible alternative is a yeast-based coproduct of bioethanol production, proteinaceous fermentation biomass. Substituting such products for engineered feed can result in equal (sometimes enhanced) growth in fish. With its increasing availability, this would address the problems of rising costs for buying hatchery fish feed.
Yet another attractive alternative is the increased use of seaweed. Seaweed provides essential minerals and vitamins for growing organisms. It offers the advantage of providing natural amounts of dietary fiber and having a lower glycemic load than grain-based fish meal. In the best-case scenario, widespread use of seaweed could yield a future in aquaculture that eliminates the need for land, freshwater, or fertilizer to raise fish.
The population of wild salmon declined markedly in recent decades, especially North Atlantic populations, which spawn in the waters of western Europe and eastern Canada, and wild salmon in the Snake and Columbia River systems in northwestern United States.
Salmon population levels are of concern in the Atlantic and in some parts of the Pacific. Alaska fishery stocks are still abundant, and catches have been on the rise in recent decades, after the state initiated limitations in 1972. Some of the most important Alaskan salmon sustainable wild fisheries are located near the Kenai River, Copper River, and in Bristol Bay. Fish farming of Pacific salmon is outlawed in the United States Exclusive Economic Zone, however, there is a substantial network of publicly funded hatcheries, and the State of Alaska's fisheries management system is viewed as a leader in the management of wild fish stocks. In Canada, returning Skeena River wild salmon support commercial, subsistence and recreational fisheries, as well as the area's diverse wildlife on the coast and around communities hundreds of miles inland in the watershed. The status of wild salmon in Washington is mixed. Of 435 wild stocks of salmon and steelhead, only 187 of them were classified as healthy; 113 had an unknown status, one was extinct, 12 were in critical condition and 122 were experiencing depressed populations.
The commercial salmon fisheries in California have been either severely curtailed or closed completely in recent years, due to critically low returns on the Klamath and or Sacramento rivers, causing millions of dollars in losses to commercial fishermen. Both Atlantic and Pacific salmon are popular sportfish.
Salmon populations have been established in all the Great Lakes. Coho stocks were planted by the state of Michigan in the late 1960s to control the growing population of non-native alewife. Now Chinook (king), Atlantic, and coho (silver) salmon are annually stocked in all Great Lakes by most bordering states and provinces. These populations are not self-sustaining and do not provide much in the way of a commercial fishery, but have led to the development of a thriving sport fishery.
Salmon is a popular food. Classified as an oily fish, 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, with a range of 23–214 mg/100 g depending on the species. According to reports in the journal Science, 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, but still well below levels considered dangerous. 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. Farmed salmon has a high omega 3 fatty acid content comparable to wild salmon. The type of omega-3 present may not be a factor for other important health functions.
Salmon flesh is generally orange to red, although white-fleshed wild salmon with white-black skin colour occurs. 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.
The vast majority of Atlantic salmon available around the world are farmed (almost 99%), whereas the majority of Pacific salmon are wild-caught (greater than 80%). Canned salmon in the US is usually wild Pacific catch, though some farmed salmon is available in canned form. Smoked salmon is another popular preparation method, and can either be hot or cold smoked. Lox can refer to either cold-smoked salmon or salmon cured in a brine solution (also called gravlax). Traditional canned salmon includes some skin (which is harmless) and bone (which adds calcium). Skinless and boneless canned salmon is also available.
Raw salmon flesh may contain Anisakis nematodes, marine parasites that cause anisakiasis. Before the availability of refrigeration, the Japanese did not consume raw salmon. Salmon and salmon roe have only recently come into use in making sashimi (raw fish) and sushi.
To the Indigenous peoples of the Pacific Northwest Coast, salmon is considered a vital part of the diet. Specifically, the indigenous peoples of Haida Gwaii, located near former Queen Charlotte Island in British Columbia, rely on salmon as one of their main sources of food, although many other bands have fished Pacific waters for centuries. Salmon are not only ancient and unique, but it is important because it is expressed in culture, art forms, and ceremonial feasts. Annually, salmon spawn in Haida, feeding on everything on the way upstream and down. Within the Haida nation, salmon is referred to as "tsiin", and is prepared in several ways including smoking, baking, frying, and making soup.
Historically, there has always been enough salmon, as people would not overfish, and only took what they needed. In 2003, a report on First Nation participation in commercial fisheries, including salmon, commissioned by BC's Ministry of Agriculture, Food and Fisheries found that there were 595 First Nation-owned and operated commercial vessels in the province. Of those vessels, First Nations’ members owned 564. However, employment within the industry has decreased overall by 50% in the last decade, with 8,142 registered commercial fishermen in 2003. This has affected employment for many fisherman, who rely on salmon as a source of income.
Black bears also rely on salmon as food. The leftovers the bears leave behind are considered important nutrients for the Canadian forest, such as the soil, trees, and plants. In this sense, the salmon feed the forest and in return receive clean water and gravel in which to hatch and grow, sheltered from extremes of temperature and water flow in times of high and low rainfall. However, the condition of the salmon in Haida has been affected in recent decades. Due to logging and development, much of the salmon's habitat (i.e., Ain River) has been destroyed, resulting in the fish being close to endangered. For residents, this has resulted in limits on catches, in turn, has affected families diets, and cultural events such as feasts. Some of the salmon systems in danger include: the Davidon, Naden, Mamim, and Mathers. It is clear that further protection is needed for salmon, such as their habitats, where logging commonly occurs.
The salmon has long been at the heart of the culture and livelihood of coastal dwellers, which can be traced as far back as 5,000 years when archeologists discovered Nisqually tribes remnants. The original distribution of the Genus Oncorhynchus covered the Pacific Rim coastline. History shows salmon used tributaries, rivers and estuaries without regard to jurisdiction for 18–22 million years. Baseline data is near impossible to recreate based on the inconsistent historical data, but confirmed there have been massive depletion since 1900s. The Pacific Northwest was once sprawled with native inhabitants who practiced eco management, to ensure little degradation was caused by their actions to salmon habitats. As animists, the indigenous people relied not only for salmon for food, but spiritual guidance. The role of the salmon spirit guided the people to respect ecological systems such as the rivers and tributaries the salmon used for spawning. Natives often used the entire fish and left no waste by creating items such turning the bladder into glue, bones for toys, and skin for clothing and shoes. The first salmon ceremony was introduced by indigenous tribes on the pacific coast, which consists of three major parts. First is the welcoming of the first catch, then comes the cooking and lastly, the return of the bones to the Sea to induce hospitality so that other salmon would give their lives to the people of that village. Many tribes such as the Yurok had a taboo against harvesting the first fish that swam upriver in summer, but once they confirmed that the salmon had returned in abundance they would begin to catch them in plentiful. The indigenous practices were guided by deep ecological wisdom, which was eradicated when Euro-American settlements began to be developed. Salmon have a much grander history than what is presently shown today. The Salmon that once dominated the Pacific Ocean are now just a fraction in population and size. The Pacific salmon population is now less than 1–3% of what it was when Lewis and Clark arrived at the region. In his 1908 State of the Union address, U.S. President Theodore Roosevelt observed that the fisheries were in significant decline:
The salmon fisheries of the Columbia River are now but a fraction of what they were twenty-five years ago, and what they would be now if the United States Government had taken complete charge of them by intervening between Oregon and Washington. During these twenty-five years the fishermen of each State have naturally tried to take all they could get, and the two legislatures have never been able to agree on joint action of any kind adequate in degree for the protection of the fisheries. At the moment the fishing on the Oregon side is practically closed, while there is no limit on the Washington side of any kind, and no one can tell what the courts will decide as to the very statutes under which this action and non-action result. Meanwhile very few salmon reach the spawning grounds, and probably four years hence the fisheries will amount to nothing; and this comes from a struggle between the associated, or gill-net, fishermen on the one hand, and the owners of the fishing wheels up the river.
On the Columbia River the Chief Joseph Dam completed in 1955 completely blocks salmon migration to the upper Columbia River system.
The salmon is an important creature in several strands of Celtic mythology and poetry, which often associated them with wisdom and venerability. In Irish mythology, a creature called the Salmon of Knowledge plays key role in the tale The Boyhood Deeds of Fionn. In the tale, the Salmon will grant powers of knowledge to whoever eats it, and is sought by poet Finn Eces for seven years. Finally Finn Eces catches the fish and gives it to his young pupil, Fionn mac Cumhaill, to prepare it for him. However, Fionn burns his thumb on the salmon's juices, and he instinctively puts it in his mouth. In so doing, he inadvertently gains the Salmon's wisdom. Elsewhere in Irish mythology, the salmon is also one of the incarnations of both Tuan mac Cairill and Fintan mac Bóchra.
Salmon also feature in Welsh mythology. In the prose tale Culhwch and Olwen, the Salmon of Llyn Llyw is the oldest animal in Britain, and the only creature who knows the location of Mabon ap Modron. After speaking to a string of other ancient animals who do not know his whereabouts, King Arthur's men Cai and Bedwyr are led to the Salmon of Llyn Llyw, who lets them ride its back to the walls of Mabon's prison in Gloucester.
In Norse mythology, after Loki tricked the blind god Höðr into killing his brother Baldr, Loki jumped into a river and transformed himself into a salmon to escape punishment from the other gods. When they held out a net to trap him he attempted to leap over it but was caught by Thor who grabbed him by the tail with his hand, and this is why the salmon's tail is tapered.
Astaxanthin (3,3'-hydroxy-β,β-carotene-4,4'-dione) is a carotenoid pigment, one of a large group of organic molecules related to vitamins and widely found in plants. In addition to providing red, orange, and yellow colours to various plant parts and playing a role in photosynthesis, carotenoids are powerful antioxidants, and some (notably various forms of carotene) are essential precursors to vitamin A synthesis in animals.
Aquaculture (less commonly spelled aquiculture), also known as aquafarming, is the farming of fish, crustaceans, molluscs, aquatic plants, algae, and other organisms. Aquaculture involves cultivating freshwater and saltwater populations under controlled conditions, and can be contrasted with commercial fishing, which is the harvesting of wild fish. Mariculture refers to aquaculture practiced in marine environments and in underwater habitats.
According to the Food and Agriculture Organization (FAO), aquaculture "is understood to mean the farming of aquatic organisms including fish, molluscs, crustaceans and aquatic plants. Farming implies some form of intervention in the rearing process to enhance production, such as regular stocking, feeding, protection from predators, etc. Farming also implies individual or corporate ownership of the stock being cultivated." The reported output from global aquaculture operations in 2014 supplied over one half of the fish and shellfish that is directly consumed by humans; however, there are issues about the reliability of the reported figures. Further, in current aquaculture practice, products from several pounds of wild fish are used to produce one pound of a piscivorous fish like salmon.Particular kinds of aquaculture include fish farming, shrimp farming, oyster farming, mariculture, algaculture (such as seaweed farming), and the cultivation of ornamental fish. Particular methods include aquaponics and integrated multi-trophic aquaculture, both of which integrate fish farming and aquatic plant farming.Aquaculture of salmonids
The aquaculture of salmonids is the farming and harvesting of salmonids under controlled conditions for both commercial and recreational purposes. Salmonids (particularly salmon and rainbow trout), along with carp, and tilapia are the three most important fish species in aquaculture. The most commonly commercially farmed salmonid is the Atlantic salmon. In the U.S. Chinook salmon and rainbow trout are the most commonly farmed salmonids for recreational and subsistence fishing through the National Fish Hatchery System. In Europe, brown trout are the most commonly reared fish for recreational restocking. Commonly farmed nonsalmonid fish groups include tilapia, catfish, sea bass, and bream.
In 2007, the aquaculture of salmonids was worth US$10.7 billion globally. Salmonid aquaculture production grew over ten-fold during the 25 years from 1982 to 2007. In 2012, the leading producers of salmonids were Norway, Chile, Scotland and Canada.Much controversy exists about the ecological and health impacts of intensive salmonids aquaculture. Of particular concern are the impacts on wild salmon and other marine life. Some of this controversy is part of a major commercial competitive fight for market share and price between Alaska commercial salmonid fishermen and the rapidly evolving salmonid aquaculture industry.Atlantic salmon
The Atlantic salmon (Salmo salar) is a species of ray-finned fish in the family Salmonidae. It is found in the northern Atlantic Ocean, in rivers that flow into the north Atlantic and, due to human introduction, in the north Pacific Ocean. Atlantic salmon have long been the target of recreational and commercial fishing, and this, as well as habitat destruction, has reduced their numbers significantly; the species is the subject of conservation efforts in several countries.Chinook salmon
The Chinook salmon (Oncorhynchus tshawytscha) is the largest species in the Pacific salmon genus Oncorhynchus. The common name refers to the Chinookan peoples. Other vernacular names for the species include king salmon, Quinnat salmon, spring salmon, chrome hog, and Tyee salmon. The scientific species name is based on the Russian common name chavycha (чавыча).
Chinook are anadromous fish native to the North Pacific Ocean and the river systems of western North America, ranging from California to Alaska, as well as Asian rivers ranging from northern Japan to the Palyavaam River in the Arctic north-east Siberia. They have been introduced to other parts of the world, including New Zealand, the Great Lakes of North America and Patagonia. A large Chinook is a prized and sought-after catch for a sporting angler. The flesh of the salmon is also highly valued for its dietary nutritional content, which includes high levels of important omega-3 fatty acids. Some populations are endangered; however, many are healthy. The Chinook salmon has not been assessed for the IUCN Red List. According to NOAA the Chinook salmon population along the California coast is declining, due to factors like overfishing, loss of freshwater and estuarine habitat, hydropower development, poor ocean conditions, and hatchery practices.Coho salmon
The coho salmon (Oncorhynchus kisutch; Karuk: achvuun) is a species of anadromous fish in the salmon family, one of the several species of Pacific salmon. Coho salmon are also known as silver salmon or "silvers". The scientific species name is based on the Russian common name kizhuch (кижуч).Fish disease and parasites
Like humans and other animals, fish suffer from diseases and parasites. Fish defences against disease are specific and non-specific. Non-specific defences include skin and scales, as well as the mucus layer secreted by the epidermis that traps microorganisms and inhibits their growth. If pathogens breach these defences, fish can develop inflammatory responses that increase the flow of blood to infected areas and deliver white blood cells that attempt to destroy the pathogens.
Specific defences are specialised responses to particular pathogens recognised by the fish's body, that is adaptative immune responses. In recent years, vaccines have become widely used in aquaculture and ornamental fish, for example vaccines for furunculosis in farmed salmon and koi herpes virus in koi.Some commercially important fish diseases are VHS, ich and whirling disease.Fish farming
Fish farming or pisciculture involves raising fish commercially in tanks or enclosures such as fish ponds, usually for food. It is the principal form of aquaculture, while other methods may fall under mariculture. A facility that releases juvenile fish into the wild for recreational fishing or to supplement a species' natural numbers is generally referred to as a fish hatchery. Worldwide, the most important fish species produced in fish farming are carp, tilapia, salmon, and catfish.Demand is increasing for fish and fish protein, which has resulted in widespread overfishing in wild fisheries. China provides 62% of the world's farmed fish. As of 2016, more than 50% of seafood was produced by aquaculture.Farming carnivorous fish, such as salmon, does not always reduce pressure on wild fisheries. Carnivorous farmed fish are usually fed fishmeal and fish oil extracted from wild forage fish. The 2008 global returns for fish farming recorded by the FAO totaled 33.8 million tonnes worth about $US 60 billion.Oncorhynchus
Oncorhynchus is a genus of fish in the family Salmonidae; it contains the Pacific salmon and Pacific trout. The name of the genus is derived from the Greek onkos ("hook") and rynchos ("nose"), in reference to the hooked jaws of males in the mating season (the "kype").Roe
Roe () or hard roe is the fully ripe internal egg masses in the ovaries, or the released external egg masses of fish and certain marine animals, such as shrimp, scallop and sea urchins. As a seafood, roe is used both as a cooked ingredient in many dishes and as a raw ingredient. The roe of marine animals, such as the roe of lumpsucker, hake and salmon, is an excellent source of omega-3 fatty acids. Roe from a sturgeon or sometimes other fish is the raw base product from which caviar is made.
The term soft roe or white roe denotes fish milt.Salmon P. Chase
Salmon Portland Chase (January 13, 1808 – May 7, 1873) was a U.S. politician and jurist who served as the sixth Chief Justice of the United States. He also served as the 23rd Governor of Ohio, represented Ohio in the United States Senate, and served as the 25th United States Secretary of the Treasury. Chase was therefore one of a few US politicians who served in all three branches of the federal government.
Born in Cornish, New Hampshire, Chase studied law under Attorney General William Wirt before establishing a legal practice in Cincinnati. He became an anti-slavery activist and frequently defended fugitive slaves in court. Chase left the Whig Party in 1841 to become the leader of Ohio's Liberty Party. In 1848, he helped establish the Free Soil Party and recruited former President Martin Van Buren to serve as the party's presidential nominee. Chase won election to the Senate the following year, and he opposed the Compromise of 1850 and the Kansas–Nebraska Act. In the aftermath of the Kansas–Nebraska Act, Chase helped establish the Republican Party, which opposed the extension of slavery into the territories. After leaving the Senate, Chase served as the Governor of Ohio from 1856 to 1860.
Chase sought the Republican nomination for president in the 1860 presidential election, but the party chose Abraham Lincoln at its National Convention. After Lincoln won the election, he asked Chase to serve as Secretary of the Treasury. Chase served in that position from 1861 to 1864, working hard to ensure the Union was well-financed during the Civil War. Chase resigned from the Cabinet in June 1864, but retained support among the Radical Republicans. Partly to appease the Radical Republicans, Lincoln nominated Chase to fill the Supreme Court vacancy that arose following Chief Justice Roger Taney's death.
Chase served as Chief Justice from 1864 to his death in 1873. He presided over the Senate trial of President Andrew Johnson during the impeachment proceedings of 1868. Despite his service on the court, Chase continued to pursue the presidency. He unsuccessfully sought the Democratic presidential nomination in 1868 and the Liberal Republican nomination in 1872.Salmon Ruins
Salmon Ruins is an ancient Chacoan and Pueblo site located in the northwest corner of New Mexico, USA. Salmon was constructed by migrants from Chaco Canyon around 1090 CE, with 275 to 300 original rooms spread across three stories, an elevated tower kiva in its central portion, and a great kiva in its plaza. Subsequent use by local Middle San Juan people (beginning in the 1120s) resulted in extensive modifications to the original building, with the reuse of hundreds of rooms, division of many of the original large, Chacoan rooms into smaller rooms, and emplacement of more than 20 small kivas into pueblo rooms and plaza areas. The site was occupied by ancient Ancestral Puebloans until the 1280s, when much of the site was destroyed by fire and abandoned (Reed 2006b). The pueblo is situated on the north bank of the San Juan River, just to the west of the modern town of Bloomfield, New Mexico, and about 45 miles (72 km) north of Pueblo Bonito in Chaco Canyon. The site was built on the first alluvial terrace above the San Juan River floodplain.
The ruins of Salmon Pueblo were excavated between 1970 and 1979, under the direction of Cynthia Irwin-Williams of Eastern New Mexico University in partnership with the San Juan County Museum Association (Irwin-Williams 2006, p. 17-27). The San Juan Valley Archaeological Program resulted in the excavation of slightly more than one-third of Salmon's ground floor rooms. More than 1.5 million artifacts and samples were recovered from Salmon. In 1980, Irwin-Williams and co-principal investigator Phillip Shelley wrote, compiled and edited a multivolume, 1,500-page report. The document fulfilled the reporting requirements for the series of grants under which the project had been completed but it was not intended for publication. Throughout the 1980s, Irwin-Williams and Shelley worked on a modified and greatly reduced manuscript, with the goal of producing a publishable report. This work ended with the untimely death of Cynthia Irwin-Williams in 1990.
In 2000, Archaeology Southwest (formerly the Center for Desert Archaeology) President Bill Doelle and staff met with Salmon Executive Director Larry Baker and forged a multiyear partnership. Archaeology Southwest's work at Salmon began in 2001 as the Salmon Reinvestment and Research Program, with archaeologist Paul Reed leading the effort. The research initiative comprised two primary tasks: first, to condense and edit the original 1980 Salmon report into a new, published technical report, and second, to conduct additional, primary research in several targeted areas, with the goal of producing material for a detailed technical report, as well as a synthetic volume. The three-volume report, entitled Thirty-Five Years of Archaeological Research at Salmon Ruins, New Mexico, was published in 2006 (Reed 2006a), followed by the synthetic-summary volume Chaco’s Northern Prodigies, published in 2008 (Reed 2008a). An additional component of the Archaeology Southwest effort at Salmon focused on the curation needs of the massive collection. These needs were partially addressed through a Save America's Treasures grant for $150,000 awarded in 2002. The curation effort (repackaging and reboxing artifacts) has continued over the last 10 years.Salmon as food
Salmon is a popular food. Classified as an oily fish, salmon is high in protein, omega-3 fatty acids, and vitamin D, and is therefore considered to be healthy.. Salmon is also a source of cholesterol, with a range of 23–214 mg/100 g depending on the species. According to reports in the journal Science, however, farmed salmon may contain high levels of dioxins. PCB levels may be up to eight times higher in farmed salmon than in wild salmon, but still far below levels considered dangerous. Nonetheless, according to a 2006 study published in the Journal of the American Medical Association, the benefits of eating even farmed salmon far outweigh any risks imposed by contaminants.Salmon run
The salmon run is the time when salmon, which have migrated from the ocean, swim to the upper reaches of rivers where they spawn on gravel beds. After spawning, all Pacific salmon and most Atlantic salmon die, and the salmon life cycle starts over again. The annual run can be a major event for grizzly bears, bald eagles and sport fishermen. Most salmon species migrate during the fall (September through November).Salmon spend their early life in rivers, and then swim out to sea where they live their adult lives and gain most of their body mass. When they have matured, they return to the rivers to spawn. Usually they return with uncanny precision to the natal river where they were born, and even to the very spawning ground of their birth. It is thought that, when they are in the ocean, they use magnetoception to locate the general position of their natal river, and once close to the river, that they use their sense of smell to home in on the river entrance and even their natal spawning ground.
In northwest America, salmon is a keystone species, which means the impact they have on other life is greater than would be expected in relation to their biomass. The death of the salmon has important consequences, since it means significant nutrients in their carcasses, rich in nitrogen, sulfur, carbon and phosphorus, are transferred from the ocean to terrestrial wildlife such as bears and riparian woodlands adjacent to the rivers. This has knock-on effects not only for the next generation of salmon, but to every species living in the riparian zones the salmon reach. The nutrients can also be washed downstream into estuaries where they accumulate and provide much support for estuarine breeding birds.Salmonidae
Salmonidae is a family of ray-finned fish, the only living family currently placed in the order Salmoniformes. It includes salmon, trout, chars, freshwater whitefishes, and graylings, which collectively are known as the salmonids. The Atlantic salmon and trout of the genus Salmo give the family and order their names.
Salmonids have a relatively primitive appearance among the teleost fish, with the pelvic fins being placed far back, and an adipose fin towards the rear of the back. They are slender fish, with rounded scales and forked tails. Their mouths contain a single row of sharp teeth. Although the smallest species is just 13 cm (5.1 in) long as an adult, most are much larger, with the largest reaching 2 m (6.6 ft).All salmonids spawn in fresh water, but in many cases, the fish spend most of their lives at sea, returning to the rivers only to reproduce. This lifecycle is described as anadromous. They are predators, feeding on small crustaceans, aquatic insects, and smaller fish.Snake River
The Snake River is a major river of the greater Pacific Northwest region in the United States. At 1,078 miles (1,735 km) long, it is the largest tributary of the Columbia River, in turn the largest North American river that empties into the Pacific Ocean. The Snake River rises in western Wyoming, then flows through the Snake River Plain of southern Idaho, the rugged Hells Canyon on the Oregon–Idaho border and the rolling Palouse Hills of Washington, emptying into the Columbia River at the Tri-Cities, Washington.
The Snake River drainage basin encompasses parts of six U.S. states and is known for its varied geologic history. The Snake River Plain was created by a volcanic hotspot which now lies underneath the Snake River headwaters in Yellowstone National Park. Gigantic glacial-retreat flooding episodes that occurred during the previous Ice Age carved out canyons, cliffs and waterfalls along the middle and lower Snake River. Two of these catastrophic flooding events, the Missoula Floods and Bonneville Flood, significantly affected the river and its surroundings.
Prehistoric Native Americans lived along the Snake starting more than 11,000 years ago. Salmon from the Pacific Ocean spawned by the millions in the river, and were a vital resource for people living on the Snake downstream of Shoshone Falls. By the time Lewis and Clark explored the area, the Nez Perce and Shoshone were the dominant Native American groups in the region. Later explorers and fur trappers further changed and used the resources of the Snake River basin. At one point, sign language used by the Shoshones representing weaving baskets was misinterpreted to represent a snake, giving the Snake River its name.By the middle 19th century, the Oregon Trail had become well established, bringing numerous settlers to the Snake River region. Steamboats and railroads moved agricultural products and minerals along the river throughout the 19th and early 20th centuries. Starting in the 1890s, fifteen major dams have been built on the Snake River to generate hydroelectricity, enhance navigation, and provide irrigation water. However, these dams blocked salmon migration above Hells Canyon and have led to water quality and environmental issues in certain parts of the river. The removal of several dams on the lower Snake River has been proposed, in order to restore some of the river's once-tremendous salmon runs.Sockeye salmon
Sockeye salmon (Oncorhynchus nerka), also called red salmon, kokanee salmon, or blueback salmon, is an anadromous species of salmon found in the Northern Pacific Ocean and rivers discharging into it. This species is a Pacific salmon that is primarily red in hue during spawning. They can grow up to 84 cm (2 ft 9 in) in length and weigh 2.3 to 7 kg (5–15 lb). Juveniles remain in freshwater until they are ready to migrate to the ocean, over distances of up to 1,600 km (1,000 mi). Their diet consists primarily of zooplankton. Sockeye salmon are semelparous, dying after they spawn. Some populations, referred to as kokanee, do not migrate to the ocean and live their entire lives in freshwater.Sushi
Sushi (すし, 寿司, 鮨, pronounced [sɯꜜɕi] or [sɯɕiꜜ]) is a Japanese dish of prepared vinegared rice (鮨飯, sushi-meshi), usually with some sugar and salt, accompanying a variety of ingredients (ネタ, neta), such as seafood, vegetables, and occasionally tropical fruits. Styles of sushi and its presentation vary widely, but the one key ingredient is "sushi rice", also referred to as shari (しゃり), or sumeshi (酢飯). The term sushi is no longer used in its original context; it literally means "sour-tasting".
Sushi is traditionally made with medium-grain white rice, though it can be prepared with brown rice or short-grain rice. It is very often prepared with seafood, such as squid, eel, yellowtail, salmon, tuna or imitation crab meat. Many types of sushi are vegetarian. It is often served with pickled ginger (gari), wasabi, and soy sauce. Daikon radish or pickled daikon (takuan) are popular garnishes for the dish.
Sushi is sometimes confused with sashimi, a related dish in Japanese cuisine that consists of thinly sliced raw fish, or occasionally meat, and an optional serving of rice.Trout
Trout is the common name for a number of species of freshwater fish belonging to the genera Oncorhynchus, Salmo and Salvelinus, all of the subfamily Salmoninae of the family Salmonidae. The word trout is also used as part of the name of some non-salmonid fish such as Cynoscion nebulosus, the spotted seatrout or speckled trout.
Trout are closely related to salmon and char (or charr): species termed salmon and char occur in the same genera as do fish called trout (Oncorhynchus – Pacific salmon and trout, Salmo – Atlantic salmon and various trout, Salvelinus – char and trout).
Lake trout and most other trout live in freshwater lakes and rivers exclusively, while there are others, such as the steelhead, which can spend two or three years at sea before returning to fresh water to spawn (a habit more typical of salmon). Steelhead that live out their lives in fresh water are called rainbow trout. Arctic char and brook trout are part of the char family. Trout are an important food source for humans and wildlife, including brown bears, birds of prey such as eagles, and other animals. They are classified as oily fish.UFC 236
UFC 236: Holloway vs. Poirier 2 was a mixed martial arts event produced by the Ultimate Fighting Championship held on April 13, 2019 at the State Farm Arena in Atlanta, Georgia.
|Atlantic and Pacific salmon|
|Genus||Image||Common name||Scientific name||Maximum
|Atlantic salmon||Salmo salar Linnaeus, 1758||150 cm||120 cm||46.8 kg||13 years||4.4||||||||Least concern|
|Chinook salmon||Oncorhynchus tshawytscha (Walbaum, 1792)||150 cm||70 cm||61.4 kg||9 years||4.4||||||||Not assessed|
|Chum salmon||Oncorhynchus keta (Walbaum, 1792)||100 cm||58 cm||15.9 kg||7 years||3.5||||||||Not assessed|
|Coho salmon||Oncorhynchus kisutch (Walbaum, 1792)||108 cm||71 cm||15.2 kg||5 years||4.2||||||||Not assessed|
|Masu salmon||Oncorhynchus masou (Brevoort, 1856)||79 cm||cm||10.0 kg||3 years||3.6||||||Not assessed|
|Pink salmon||Oncorhynchus gorbuscha (Walbaum, 1792)||76 cm||50 cm||6.8 kg||3 years||4.2||||||||Not assessed|
|Sockeye salmon||Oncorhynchus nerka (Walbaum, 1792)||84 cm||58 cm||7.7 kg||8 years||3.7||||||||Least concern|
|Some other fishes called salmon|
|Common name||Scientific name||Maximum
|Australian salmon||Arripis trutta (Forster, 1801)||89 cm||47 cm||9.4 kg||26 years||4.1||||||Not assessed|
|Danube salmon||Hucho hucho (Linnaeus, 1758)||150 cm||70 cm||52 kg||15 years||4.2||||||Endangered|
|Hawaiian salmon||Elagatis bipinnulata (Quoy & Gaimard, 1825)||180 cm||90 cm||46.2 kg||years||3.6||||||||Not assessed|
|Indian salmon||Eleutheronema tetradactylum (Shaw, 1804)||200 cm||50 cm||145 kg||years||4.4||||||Not assessed|
Principal commercial fishery species groups