''Oncorhynchus'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

of fish in the

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

Salmonidae; it contains the Pacific salmon and Pacific trout. The name of the genus is derived from the Greek ὄγκος (ónkos, “lump, bend”) + ῥύγχος (rhúnkhos, “snout”), in reference to the hooked

snout A snout is the protruding portion of an animal's face, consisting of its nose, mouth, and jaw. In many animals, the structure is called a muzzle, rostrum, or proboscis. The wet furless surface around the nostrils of the nose of many mammals is ...

(the " kype") that the males develop during mating season.

Range

Salmon Salmon () is the common name for several commercially important species of euryhaline ray-finned fish from the family Salmonidae, which are native to tributaries of the North Atlantic (genus '' Salmo'') and North Pacific (genus '' Onco ...

and

trout Trout are 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-salm ...

with native ranges in waters draining to the

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the conti ...

are members of the genus. Their range extends from

Beringia Beringia is defined today as the land and maritime area bounded on the west by the Lena River in Russia; on the east by the Mackenzie River in Canada; on the north by 72 degrees north latitude in the Chukchi Sea; and on the south by the tip ...

southwards, roughly to

Taiwan Taiwan, officially the Republic of China (ROC), is a country in East Asia, at the junction of the East and South China Seas in the northwestern Pacific Ocean, with the People's Republic of China (PRC) to the northwest, Japan to the no ...

in the west and

Mexico Mexico (Spanish language, Spanish: México), officially the United Mexican States, is a List of sovereign states, country in the southern portion of North America. It is borders of Mexico, bordered to the north by the United States; to the so ...

to the east. In

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and th ...

, some subspecies of '' O. clarkii'' are native in the

Rocky Mountains The Rocky Mountains, also known as the Rockies, are a major mountain range and the largest mountain system in North America. The Rocky Mountains stretch in straight-line distance from the northernmost part of western Canada, to New Mexico ...

and

Great Basin The Great Basin is the largest area of contiguous endorheic watersheds, those with no outlets, in North America. It spans nearly all of Nevada, much of Utah, and portions of California, Idaho, Oregon, Wyoming, and Baja California. It is noted fo ...

, while others are native to the

Rio Grande The Rio Grande ( and ), known in Mexico as the Río Bravo del Norte or simply the Río Bravo, is one of the principal rivers (along with the Colorado River) in the southwestern United States and in northern Mexico. The length of the Rio G ...

and western tributaries of the Mississippi River Basin which drain to the

Gulf of Mexico The Gulf of Mexico ( es, Golfo de México) is an ocean basin and a marginal sea of the Atlantic Ocean, largely surrounded by the North American continent. It is bounded on the northeast, north and northwest by the Gulf Coast of the United ...

, rather than to the Pacific. Several species of ''Oncorhynchus'' have been introduced into non-native waters around the globe, establishing self-sustaining wild populations. The six Pacific salmons of ''Oncorhynchus'' are

anadromous Fish migration is mass relocation by fish from one area or body of water to another. Many types of fish migrate on a regular basis, on time scales ranging from daily to annually or longer, and over distances ranging from a few metres to thousa ...

(migratory) and semelparous (die after

spawn Spawn or spawning may refer to: * Spawn (biology), the eggs and sperm of aquatic animals Arts, entertainment, and media * Spawn (character), a fictional character in the comic series of the same name and in the associated franchise ** '' Spawn: A ...

ing). Migration can be affected by

parasite Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson h ...

s. Infected individuals can become weak and probably have shortened lifespans. Infection with parasites creates an effect known as

culling In biology, culling is the process of segregating organisms from a group according to desired or undesired characteristics. In animal breeding, it is the process of removing or segregating animals from a breeding stock based on a specific tr ...

whereby fish that are infected are less likely to complete the migration. Anadromous forms of ''Oncorhynchus mykiss'' known as steelhead are iteroparous. The

coastal cutthroat trout The coastal cutthroat trout (''Oncorhynchus clarkii clarkii''), also known as the sea-run cutthroat trout, blue-back trout or harvest trout, is one of the several subspecies of cutthroat trout found in Western North America. The coastal cutthroa ...

(''Oncorhynchus clarkii clarkii'') is considered semi-anadromous, as it spends some time in the ocean, usually much closer to its native stream than its fully anadromous relatives.

Evolution

Several Late

Miocene The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recen ...

(about 7 million years ago ( Mya)) trout-like fossils in

Idaho Idaho ( ) is a U.S. state, state in the Pacific Northwest region of the Western United States. To the north, it shares a small portion of the Canada–United States border with the province of British Columbia. It borders the states of Monta ...

, in the Clarkia Lake beds, appear to be of '' Oncorhynchus''. The presence of these species so far inland established ''Oncorhynchus'' was not only present in the Pacific drainages before the beginning of the

Pliocene The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58rainbow and

cutthroat trout The cutthroat trout is a fish species of the family Salmonidae native to cold-water tributaries of the Pacific Ocean, Rocky Mountains, and Great Basin in North America. As a member of the genus '' Oncorhynchus'', it is one of the Pacific t ...

, and Pacific salmon lineages had diverged before the beginning of the Pliocene. Consequently, the split between ''Oncorhynchus'' and '' Salmo'' (Atlantic salmon) must have occurred well before the Pliocene. Suggested dates have gone back as far as the Early Miocene (about 20 Mya). One fossil species assigned to this genus, '' O. rastrosus'', the saber-toothed salmon (

synonym A synonym is a word, morpheme, or phrase that means exactly or nearly the same as another word, morpheme, or phrase in a given language. For example, in the English language, the words ''begin'', ''start'', ''commence'', and ''initiate'' are al ...

''Smilodonichthys''), is a -long species known from Late Miocene to

Pleistocene The Pleistocene ( , often referred to as the ''Ice age'') is the geological Epoch (geology), epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fina ...

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

Speciation Speciation is the evolutionary process by which populations evolve to become distinct species. The biologist Orator F. Cook coined the term in 1906 for cladogenesis, the splitting of lineages, as opposed to anagenesis, phyletic evolution withi ...

among ''Oncorhynchus'' has been examined for decades, and a family "tree" is not yet completely developed for the Pacific salmonids.

Mitochondrial DNA Mitochondrial DNA (mtDNA or mDNA) is the DNA located in mitochondria, cellular organelles within eukaryotic cells that convert chemical energy from food into a form that cells can use, such as adenosine triphosphate (ATP). Mitochondrial D ...

(mtDNA) research has been completed on a variety of Pacific trout and salmonid species, but the results do not necessarily agree with fossil research, or molecular research.

Chum Chum may refer to: Broadcasting * CHUM Limited, a defunct Canadian media company * CHUM Radio, now Bell Media Radio, a Canadian radio broadcasting company * CHUM (AM), a Toronto radio station * CHUM-FM, a Toronto radio station * CHUM Chart, ...

pink Pink is the color of a namesake flower that is a pale tint of red. It was first used as a color name in the late 17th century. According to surveys in Europe and the United States, pink is the color most often associated with charm, politeness, ...

and

sockeye salmon The sockeye salmon (''Oncorhynchus nerka''), also called red salmon, kokanee salmon, blueback salmon, or simply sockeye, is an anadromous species of salmon found in the Northern Pacific Ocean and rivers discharging into it. This species is a ...

lineages are generally agreed to have diverged in the sequence after other species. Montgomery (2000) discusses the pattern of the fossil record as compared to

tectonic Tectonics (; ) are the processes that control the structure and properties of the Earth's crust and its evolution through time. These include the processes of mountain building, the growth and behavior of the strong, old cores of continents ...

shifts in the plates of the

Pacific Northwest The Pacific Northwest (sometimes Cascadia, or simply abbreviated as PNW) is a geographic region in western North America bounded by its coastal waters of the Pacific Ocean to the west and, loosely, by the Rocky Mountains to the east. Thou ...

of America. The (potential)

divergence In vector calculus, divergence is a vector operator that operates on a vector field, producing a scalar field giving the quantity of the vector field's source at each point. More technically, the divergence represents the volume density of ...

in ''Onchorhyncus'' lineages appear to follow the uprising of the Pacific Rim. The climatic and habitat changes that would follow such a geologic event are discussed, in the context of potential stressors leading to adaptation and speciation. One interesting case involving speciation with salmon is that of the kokanee (

landlocked A landlocked country is a country that does not have territory connected to an ocean or whose coastlines lie on endorheic basins. There are currently 44 landlocked countries and 4 landlocked de facto states. Kazakhstan is the world's largest ...

) sockeye. Kokanee sockeye evolve differently from

sockeye—they reach the level of "biological species". Biological species—as opposed to morphological species—are defined by the capacity to maintain themselves in

sympatry In biology, two related species or populations are considered sympatric when they exist in the same geographic area and thus frequently encounter one another. An initially interbreeding population that splits into two or more distinct species s ...

as independent genetic entities. This definition can be vexing because it apparently applies only to sympatry, and this limitation makes the definition difficult to apply. Examples in

Washington State Washington (), officially the State of Washington, is a U.S. state, state in the Northwestern United States, Pacific Northwest region of the Western United States. Named for George Washington—the first President of the United States, U.S. p ...

Canada Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by to ...

, and elsewhere have two populations living in the same lake, but

ing in different substrates at different times, and eating different food sources. There is no pressure to compete or interbreed (two responses when resources are short). These types of kokanee salmon show the principal attributes of a biological species: they are reproductively isolated and show strong resources partitioning.

Decline of ''Oncorhynchus'' populations

A general decline in overall Pacific salmon populations began in the mid-19th century. As the result of western expansion and development in the U.S., experts estimate salmon populations in the

Columbia River The Columbia River ( Upper Chinook: ' or '; Sahaptin: ''Nch’i-Wàna'' or ''Nchi wana''; Sinixt dialect'' '') is the largest river in the Pacific Northwest region of North America. The river rises in the Rocky Mountains of British Columbia ...

basin had been reduced to less than 20% of their pre-1850 levels by 1933. In 2008, Lackey estimated that Pacific salmon stocks in the Pacific Northwest were less than 10% of their pre-1850 numbers. Many of the remaining salmon runs are dominated by hatchery-raised salmon, not wild salmon. Many isolated subspecies of the Pacific trouts, particularly those of ''Oncorhynchus mykiss''

rainbow trout The rainbow trout (''Oncorhynchus mykiss'') is a species of trout native to cold-water tributaries of the Pacific Ocean in Asia and North America. The steelhead (sometimes called "steelhead trout") is an anadromous (sea-run) form of the coast ...

and ''Oncorhynchus clarki''

have declined in their native ranges. Many local populations or distinct population segments of anadromous forms of steelhead have declined in their native ranges. The resulting declines have resulted in a number of populations of ''Oncorhynchus'' species or subspecies being listed as either

endangered An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching and in ...

threatened Threatened species are any species (including animals, plants and fungi) which are vulnerable to endangerment in the near future. Species that are threatened are sometimes characterised by the population dynamics measure of '' critical depe ...

or as "Species of Special Concern" by state, federal or international authorities. Two ''Oncorhynchus clarki'' subspecies are considered

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

. Declines are attributed to a wide variety of causes—overfishing, habitat loss and degradation, artificial propagation, stocking, and hybridization with or competition with introduced, non-native species. For example, the yellowfin cutthroat trout (''Oncorhynchus clarki macdonaldi'') is extinct as a result of the introduction of non-native rainbow trout into its native waters. Pacific salmon body size declines are significant and nonlinear

Pacific salmon body size declines are significant and nonlinear

Pacific salmon size declines could result in negative consequences for ecosystems and people

In August 2020 researchers reported that widespread declines in Pacific salmon size resulted in substantial losses to

ecosystem An ecosystem (or ecological system) consists of all the organisms and the physical environment with which they interact. These biotic and abiotic components are linked together through nutrient cycles and energy flows. Energy enters the syst ...

s and people, which they estimate, and are associated with a number of factors that include climate change and competition with growing numbers of wild and hatchery salmon. CC-BY icon

Text and images are available under
Creative Commons Attribution 4.0 International License

Influence of hatcheries

Declines in the abundance of wild salmon due to over fishing placed greater pressure on hatcheries to increase production and restore the wild salmon stock to supply fisheries. The problem is that hatcheries can never truly replicate the environment of wild salmon, an issue which often results in physiological and behavioral differences between wild salmon and those reared in hatcheries. These differences are often the product of genetic changes associated with

inbreeding Inbreeding is the production of offspring from the mating or breeding of individuals or organisms that are closely related genetically. By analogy, the term is used in human reproduction, but more commonly refers to the genetic disorders a ...

artificial selection Selective breeding (also called artificial selection) is the process by which humans use animal breeding and plant breeding to selectively develop particular phenotypic traits (characteristics) by choosing which typically animal or plant ma ...

, and

natural selection Natural selection is the differential survival and reproduction of individuals due to differences in phenotype. It is a key mechanism of evolution, the change in the heritable traits characteristic of a population over generations. Cha ...

, as well as different environmental pressures acting on hatchery fish than wild populations. Due to the size selective nature of fishing favoring larger fish, a reduction in average size of the adult salmon has been observed over time. The smaller salmon make a greater proportion of the remaining individuals continuing the population, and problems arise when these hatchery-reared fish are introduced into the wild populations. Unlike wild salmon, larger salmon are selected for in hatcheries and are typically much larger than wild salmon. The result is that hatchery-produced salmon tend to out-compete wild salmon for space, food, and other resources. Some salmon species in hatcheries exhibit predatory behavior toward wild salmon because they grow to be much larger. Regardless of whether predation is observed, natural social interactions are disturbed by the release of large numbers of hatchery-reared salmon where wild populations are low because salmon in hatcheries naturally have a higher propensity towards

aggressive behavior Aggression is overt or covert, often harmful, social interaction with the intention of inflicting damage or other harm upon another individual; although it can be channeled into creative and practical outlets for some. It may occur either reacti ...

. Overall, natural salmon populations are put at risk when hatchery-reared salmon populations are introduced due to competition for resources, predation by larger individuals, and negative social interactions that upset the natural order observed in wild salmon populations. As a result, wild salmon populations are steadily dropping as the pressure to continue breeding salmon in hatcheries increases. Conservation efforts that work to place limitations on hatcheries to increase the wild salmon populations are hindered by financial pressures because hatcheries effectively support many states

economically Economics () is the social science that studies the production, distribution, and consumption of goods and services. Economics focuses on the behaviour and interactions of economic agents and how economies work. Microeconomics analyze ...

by accounting for over 70% of the salmon harvested for

recreational Recreation is an activity of leisure, leisure being discretionary time. The "need to do something for recreation" is an essential element of human biology and psychology. Recreational activities are often done for enjoyment, amusement, or pleas ...

and commercial purposes.

Influence of overfishing

Pacific salmon are harvested throughout the world as a source of food in countries ranging from the United States to South Korea.Groot, Cornelis, and Leo Margolis. (1991) Pacific salmon life histories. UBC press. Over the past century, Pacific salmon have been extensively fished through both

artisan An artisan (from french: artisan, it, artigiano) is a skilled craft worker who makes or creates material objects partly or entirely by hand. These objects may be functional or strictly decorative, for example furniture, decorative art ...

and

commercial fishing Commercial fishing is the activity of catching fish and other seafood for commercial profit, mostly from wild fisheries. It provides a large quantity of food to many countries around the world, but those who practice it as an industry must oft ...

. In fact, since the 1970s there has been a nearly threefold increase in catch of Pacific salmon. As this catch has increased, a selection of reduced body size has been observed. In Japanese

chum salmon The chum salmon (''Oncorhynchus keta''), also known as dog salmon or keta salmon, is a species of anadromous salmonid fish from the genus '' Oncorhynchus'' (Pacific salmon) native to the coastal rivers of the North Pacific and the Beringian A ...

, for example, between 1970 and 1988 there has been a continuous decrease in body weight averaging between 11 and 32 percent. In part, this decline in body weight has been related to the size selective effect of fishing gear used in the harvesting of salmon populations. Salmon of larger body weight are more apt to be caught during fishing efforts, causing lower body weight to be a beneficial character trait for survival. Thus, Pacific salmon have become continuously smaller in body size. However, studies have also shown that for Pacific salmon, a larger mean size at the time of reproduction increases the survival of

offspring In biology, offspring are the young creation of living organisms, produced either by a single organism or, in the case of sexual reproduction, two organisms. Collective offspring may be known as a brood or progeny in a more general way. This ca ...

. The life history of salmon favors delayed reproduction because fecundity increased with body size. Consequently, the smaller body size of salmon results in a negative impact on population growth by decreasing the survivability of progeny, and thus decreasing the growth rate of populations. This reduction of productivity in Pacific salmon is, in part, seeded in

overfishing Overfishing is the removal of a species of fish (i.e. fishing) from a body of water at a rate greater than that the species can replenish its population naturally (i.e. the overexploitation of the fishery's existing fish stock), resulting in t ...

and has caused a reduction in population sizes throughout Pacific salmon species. Today, it seems that population numbers of Pacific salmon are on the rise; however, the consequences from the overfishing in the 70s and 80s are still being reflected, with the average body size of salmon being smaller than before the event of overfishing.

Conservation

Canadian efforts

There has been evidence that the sockeye salmon are affected by thermal conditions and their responses to temperature are relatively strong and tend to vary from region to region. Canada has also used the Species at Risk Act to recognize the importance of biological diversity when it comes to the conservation of the salmon population. This means that multiple species of salmon would be looked at when it comes to conservation as well as multiple areas that each species live in. COSEWIC, a Canadian organization for the conservation of species, has named the Interior

Fraser River The Fraser River is the longest river within British Columbia, Canada, rising at Fraser Pass near Blackrock Mountain in the Rocky Mountains and flowing for , into the Strait of Georgia just south of the City of Vancouver. The river's annual ...

Coho, the Cultus Lake Sockeye, and the Sakinaw Lake Sockeye to all be endangered. In

British Columbia British Columbia (commonly abbreviated as BC) is the westernmost province of Canada, situated between the Pacific Ocean and the Rocky Mountains. It has a diverse geography, with rugged landscapes that include rocky coastlines, sandy beaches, for ...

sockeye salmon in four different watersheds were certified by the

Marine Stewardship Council The Marine Stewardship Council (MSC) is a non-profit organization which aims to set standards for sustainable fishing. Fisheries that wish to demonstrate they are well-managed and sustainable compared to the MSC's standards are assessed by a t ...

, or MSC, as sustainable fisheries in July 2010 and the certification is good for a period of five years. In 2011 MSC also certified the Pink Salmon Fishery and as of 2012 The Chum Salmon Fisheries started their review under the MSC to become certified as a

sustainable fishery A conventional idea of a sustainable fishery is that it is one that is harvested at a sustainable rate, where the fish population does not decline over time because of fishing practices. Sustainability in fisheries combines theoretical discipli ...

.Certification Status of Pacific Salmon Fisheries. State of the Salmon. N.p., n.d. Web.

American efforts

The US government has been working to develop a nationwide policy for the salmon populations. The Pacific Salmon Stronghold Conservation Act was re-submitted to congress and if passed will create geographic strongholds for salmon populations.The Salmon Stronghold Initiative. Wild Salmon Center. N.p., n.d. Web. Other policies include the Wild Salmon Policy which was enacted in 2005; its number one focus is the conservation of salmon off of the coasts. Even localized policies have begun, with one in Oregon which focuses on the southernmost watershed and was approved January 2013. In the Alaskan efforts, there is evidence of eight known regional groups of survival. It is also seen that the emigration of smolts (young salmon) from freshwater to other areas such as marine areas have shown significant consequences on the survival of different salmon groups. The Alaska Department of Fish and Game first received MSC, Marine Stewardship Council, Certification in sustainable seafood back in 2000. Each certification is good for a period of five years, with yearly check ups to ensure that the fishery remains sustainable. It was renewed again in 2007, but in 2012 The ADFG left the program. The

Annette Island Annette Island or ''Taak'w Aan'' (Tlingit) is an island in the Gravina Islands of the Alexander Archipelago of the Pacific Ocean on the southeastern coast of the U.S. state of Alaska. It is at . It is about long and about wide. The land are ...

Reserve salmon fishery is under the control of the Metlakatla Indian community and as such was not included in the previous assessments of the Alaskan fisheries. It received its sustainability certification in June 2011. The Wild Salmon Center is a nonprofit organization that works on promoting conservation efforts for salmon worldwide and in the United States; it has helped secure protected watershed areas for Russian and west coast salmon. Other efforts of the Wild Salmon Center include combating

illegal fishing Illegal, unreported and unregulated fishing (IUU) is an issue around the world. Fishing industry observers believe IUU occurs in most fisheries, and accounts for up to 30% of total catches in some important fisheries. Illegal fishing takes p ...

, maintaining sustainable fisheries, and creating local watersheds as new habitats.

Russian efforts

Poaching is a threat to ''Oncorhynchus'' salmon and steelhead populations in

Russia Russia (, , ), or the Russian Federation, is a transcontinental country spanning Eastern Europe and Northern Asia. It is the largest country in the world, with its internationally recognised territory covering , and encompassing one-ei ...

. It is estimated that illegal catching of salmon is 1.5 times more than the reported catch. The Wild Salmon Center is working with Russian authorities to try to help improve traceability systems so that markets can distinguish between legal sustainable salmon and the illegal salmon. The Wild Salmon Center has secured some of its protected locations for the salmon populations. In efforts with the WWF, the Wild Salmon Center was also able to have a Sockeye Salmon fishery certified as completely sustainable in 2012. The Iturup Island Pink and Chum Salmon Fishery was first certified in 2009 and was the first Russian salmon fishery to receive certification in sustainability by MSC. Other fisheries that were certified by MSC include the Northeast

Sakhalin Island Sakhalin ( rus, Сахали́н, r=Sakhalín, p=səxɐˈlʲin; ja, 樺太 ''Karafuto''; zh, c=, p=Kùyèdǎo, s=库页岛, t=庫頁島; Manchu: ᠰᠠᡥᠠᠯᡳᠶᠠᠨ, ''Sahaliyan''; Orok: Бугата на̄, ''Bugata nā''; Nivkh ...

Pink Salmon, certified in June 2012, and the Ozernaya River Sockeye Salmon, certified in September 2012. The

Aniva Bay Aniva Bay (Russian: Залив Анива (''Zaliv Aniva''), Japanese: 亜庭湾, Aniwa Bay, or Aniva Gulf) is located at the southern end of Sakhalin Island, Russia, north of the island of Hokkaidō, Japan. The largest city on the bay is Kors ...

Pink Salmon and the Sakhalin Island Pink salmon are both under review by the MSC.

Introductions and aquaculture

Several species of ''Oncorhynchus'' have been successfully introduced into non-native waters, establishing self-sustaining wild populations. The

Rainbow Trout The rainbow trout (''Oncorhynchus mykiss'') is a species of trout native to cold-water tributaries of the Pacific Ocean in Asia and North America. The steelhead (sometimes called "steelhead trout") is an anadromous (sea-run) form of the coast ...

''Oncorhynchus mykiss'' is the most widely introduced species of the genus. Rainbow Trout,

Chinook Salmon The Chinook salmon (''Oncorhynchus tshawytscha'') is the largest and most valuable species of Pacific salmon in North America, as well as the largest in the genus '' Oncorhynchus''. Its common name is derived from the Chinookan peoples. Other ...

''Oncorhynchus tshawytscha'' and

Coho Salmon The coho salmon (''Oncorhynchus kisutch;'' Karuk: achvuun) is a species of anadromous fish in the salmon family (biology), family and one of the five Pacific salmon species. Coho salmon are also known as silver salmon or "silvers". The scientif ...

''Oncorhynchus kisutch'' have established wild, self-sustaining populations in the

Great Lakes The Great Lakes, also called the Great Lakes of North America, are a series of large interconnected freshwater lakes in the mid-east region of North America that connect to the Atlantic Ocean via the Saint Lawrence River. There are five lakes ...

and Chinook in

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island coun ...

(known there as quinnat, king or spring salmon).

Aquaculture Aquaculture (less commonly spelled aquiculture), also known as aquafarming, is the controlled cultivation ("farming") of aquatic organisms such as fish, crustaceans, mollusks, algae and other organisms of value such as aquatic plants (e.g. lot ...

of Chinook and Coho salmon and Rainbow Trout are major industries in

Chile Chile, officially the Republic of Chile, is a country in the western part of South America. It is the southernmost country in the world, and the closest to Antarctica, occupying a long and narrow strip of land between the Andes to the eas ...

and

Australia Australia, officially the Commonwealth of Australia, is a sovereign country comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands. With an area of , Australia is the largest country by ...

. Chinook from Chile were released into Argentinean rivers and there were stockings of Coho and Sockeye Salmon and Rainbow Trout in Patagonia.

Species

Some of the species in this genus are highly variable and a number of now-obsolete taxa have been described. In 1989, morphological and genetic studies by Gerald Smith and Ralph Stearley indicated that trouts of the Pacific basin were genetically closer to Pacific salmon (''Onchorhynchus'' species) than to the '' Salmos'' –

brown trout The brown trout (''Salmo trutta'') is a European species of salmonid fish that has been widely introduced into suitable environments globally. It includes purely freshwater populations, referred to as the riverine ecotype, ''Salmo trutta'' morp ...

(''Salmo trutta'') or

Atlantic salmon The Atlantic salmon (''Salmo salar'') is a species of ray-finned fish in the family Salmonidae. It is the third largest of the Salmonidae, behind Siberian taimen and Pacific Chinook salmon, growing up to a meter in length. Atlantic salmon are ...

(''Salmo salar'') of the

Atlantic basin The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the "Old World" of Africa, Europe an ...

. Thus, in 1989, taxonomic authorities moved the Rainbow, Cutthroat and other Pacific basin trouts into the genus ''Oncorhynchus''. Currently, 12 species and numerous subspecies in this genus are recognized: Behnke (2002). *

Notes

References

* (2002): ''Trout and Salmon of North America''. Free Press, 2002. * (2002): Osteichthyes. ''In:'' A compendium of fossil marine animal genera. ''Bulletin of American Paleontology'' 364: 560
HTML fulltext
* (1993): Phylogeny of the Pacific trout and salmon (''Oncorhynchus'') and the genera of family Salmonidae. ''Transactions of the American Fisheries Society'' 122(1): 1-33.
HTML fulltext
* (2005) ''The distribution of Pacific salmon (Oncorhynchus spp.) in the Canadian western Arctic''. http://www.dfo-mpo.gc.ca/Library/321160.pdf * *

External links

British Columbia Salmon Farmer's Association

Global Aquaculture AllianceUS mulls Pacific salmon fishing banWatershed Watch Salmon Society
A British Columbia advocacy group for wild salmon

- Watershed Watch Salmon Society. Animated short video based on peer-reviewed scientific research, with subject background article ''Watching out for Wild Salmon''.

- Watershed Watch Salmon Society. Short video documentary. Prominent scientists and First Nation representatives speak their minds about the salmon farming industry and the effects of sea lice infestations on wild salmon populations. {{Taxonbar, from=Q133325 Taxa named by George Suckley Ray-finned fish genera Extant Miocene first appearances