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75-718: The Oyashio Current ( 親潮 , "Parental Tide") , also known as the Okhotsk Current or Kurile Current , is a cold subarctic ocean current that flows south and circulates counterclockwise in the western North Pacific Ocean . The waters of the Oyashio Current originate in the Arctic Ocean and flow southward via the Bering Sea , passing through the Bering Strait and transporting cold water from

150-506: A common ancestor . The Eocene salmon's fossil from British Columbia 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 10 to 20 million years ago during the Miocene . This independent evidence from DNA analysis and the fossil record indicate that salmon divergence occurred long before

225-442: 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. This body chemistry change is hormone-driven, causing physiological adjustments in the function of osmoregulatory organs such as

300-477: 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

375-569: A high demand for wild forage fish . As a predator, 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 kilogram of salmon. As the salmon farming industry expands, it requires more 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

450-548: 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

525-683: A mean depth of 859 metres (2,818 ft) and a maximum depth of 3,372 metres (11,063 ft). It is connected to the Sea of Japan on either side of Sakhalin: on the west through the Sakhalin Gulf and the Gulf of Tartary ; on the south through the La Pérouse Strait . In winter, navigation on the Sea of Okhotsk is impeded by ice floes . Ice floes form due to the large amount of freshwater from

600-517: A narrow strait. The first detailed summary of the hydrology of the Sea of Okhotsk was prepared and published by Stepan Makarov in 1894. The Sea of Okhotsk is rich in biological resources, with various kinds of fish, shellfish and crabs. The harsh conditions of crab fishing in the Sea of Okhotsk is the subject of the most famous novel of the Japanese writer Takiji Kobayashi , The Crab Cannery Ship (1929). The Peanut Hole (named for its shape)

675-618: A storm in the Sea of Okhotsk, some 124 km (77 mi) from Sakhalin island, where it was being towed from Kamchatka . Reportedly, its pumps failed, causing it to take on water and sink. The platform carried 67 people, of which 14 were rescued by the Magadan and the tugboat Natftogaz-55 . The platform was subcontracted to a company working for the Russian energy giant Gazprom . Salmon all other members of Salmoninae Salmon ( / ˈ s æ m ən / ; pl. : salmon)

750-412: A technically demanding kind of sport fishing , not necessarily intuitive 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

825-573: A way that all the narrow waters between Hokusyû and Kamchatka are included in the Sea of Okhotsk. Some of the Sea of Okhotsk's islands are quite large, including Japan's second-largest island, Hokkaido, as well as Russia's largest island, Sakhalin. Practically all of the sea's islands are either in coastal waters or belong to the various islands making up the Kuril Islands chain. These fall either under undisputed Japanese or Russian ownership or disputed ownership between Japan and Russia. Iony Island

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900-858: 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 , and need to be fed meals produced from catching other wild forage fish and other marine organisms. Salmon farming leads to

975-680: Is derived from Middle English : samoun , samon and saumon , which in turn are from Anglo-Norman : saumon , from Old French : saumon , and from Latin : salmō (which in turn might have originated from salire , meaning "to leap". ). The unpronounced "l" absent from Middle English was later added as a Latinisation to make the word closer to its Latin root. The term salmon has mostly displaced its now dialectal synonym lax , in turn from Middle English : lax , from Old English : leax , from Proto-Germanic : * lahsaz from Proto-Indo-European : *lakso- . The seven commercially important species of salmon occur in two genera of

1050-441: 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 m (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

1125-966: 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

1200-488: Is the common name for several commercially important species of euryhaline ray-finned fish from the genera Salmo and Oncorhynchus of the family Salmonidae , native to tributaries of the North Atlantic ( Salmo ) and North Pacific ( Oncorhynchus ) basins. Other closely related fish in the same family include trout , char , grayling , whitefish , lenok and taimen , all coldwater fish of

1275-591: Is the only island located in open waters and belongs to the Khabarovsk Krai of the Russian Federation . The majority of the sea's islands are uninhabited, making them ideal breeding grounds for seals , sea lions , seabirds , and other sea island fauna. Large colonies of crested auklets use the Sea of Okhotsk as a nesting site. The Okhotsk culture and the later Ainu people , a coastal fishing and hunter-gatherer people, were located around

1350-480: 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

1425-481: The Amur River , lowering the salinity of upper levels, often raising the freezing point of the sea surface. The distribution and thickness of ice floes depends on many factors: the location, the time of year, water currents, and the sea temperatures. Cold air from Siberia forms sea ice in the northwestern Sea of Okhotsk. As the ice forms, it expels salt into the deeper layers. This heavy water flows east toward

1500-624: 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,

1575-489: The Japanese word for trout. On the other hand, the steelhead and sea trout , the anadromous forms of rainbow trout and brown trout respectively, are from the same genera as salmon and live identical migratory lives, but neither is termed "salmon" . The extinct Eosalmo driftwoodensis , the oldest known Salmoninae fish in the fossil record , helps scientists figure how the different species of salmon diverged from

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1650-526: The Pacific Northwest and Alaska , salmon are keystone species . The migration of salmon represent a massive retrograde nutrient transfer, rich in nitrogen , sulfur , carbon and phosphorus , from the ocean to the inland freshwater ecosystems . Predation by piscivorous land animals (such as ospreys , bears and otters ) along the journey serve to transfer the nutrients from the water to land, and decomposition of salmon carcass benefits

1725-461: 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 μPa s. As can be seen from the production chart at

1800-514: The Quaternary glaciation began the cycle of glacial advance and retreat. There are several other species of fish which are colloquially called "salmon" but are not true salmon. Of those listed below, the Danube salmon or huchen is a large freshwater salmonid closely related (from the same subfamily) to the seven species of salmon above, but others are fishes of unrelated orders , given

1875-672: The Salmo and Oncorhynchus genera also contain a number of trout species informally referred to as salmon. Within Salmo , the Adriatic salmon ( Salmo obtusirostris ) and Black Sea salmon ( Salmo labrax ) have both been named as salmon in English , although they fall outside the generally recognized seven salmon species. The masu salmon ( Oncorhynchus masou ) is actually considered a trout ("cherry trout") in Japan , with masu actually being

1950-508: The Soviet attack on Korean Air Lines Flight 007 in 1983. The Soviet Pacific Fleet used the sea as a ballistic missile submarine bastion , a strategy that Russia continues. Despite its proximity to Japan, the Sea of Okhotsk has no native etymology in the Japanese language ; its name, Ohōtsuku-kai ( オホーツク海 ), is a transcription of the Russian name. This is also reflected in the name of Hokkaidō's Okhotsk Subprefecture , which faces

2025-524: The Soviet Union occupied the territory. During the Cold War , the Sea of Okhotsk was the scene of several successful U.S. Navy operations (including Operation Ivy Bells ) to tap Soviet Navy undersea communications cables. These operations were documented in the 1998 book Blind Man's Bluff: The Untold Story of American Submarine Espionage . The sea (and surrounding area) were also the scene of

2100-497: The forest ecosystem . In the case of Pacific salmon , most (if not all) of the salmon that survive to reach the headwater spawning grounds will die after laying eggs and their dead bodies sink to cover the gravel beds, with the nutrients released from the biodegradation of their corpses providing a significant boost to these otherwise biomass -poor shallow streams. Grizzly bears function as ecosystem engineers , capturing salmon and carrying them into adjacent dry land to eat

2175-524: 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 by larger fish. 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

2250-590: 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

2325-616: The subarctic and cooler temperate regions with some sporadic endorheic populations in Central Asia . Salmon are typically anadromous : they hatch in the shallow gravel beds of freshwater headstreams and spend their juvenile years in rivers , lakes and freshwater wetlands , migrate to the ocean as adults and live like sea fish , then return to their freshwater birthplace to reproduce . However, populations of several species are restricted to fresh waters (i.e. landlocked) throughout their lives. Folklore has it that

Oyashio Current - Misplaced Pages Continue

2400-849: The subfamily Salmoninae . The genus Salmo contains the Atlantic salmon , found in both sides of the North Atlantic , as well as more than 40 other species commonly named as trout . The genus Oncorhynchus contains 12 recognised species which occur naturally only in the North Pacific, six of which are known as Pacific salmon while the remainder are considered trout. Outside their native habitats, Chinook salmon have been successfully introduced in New Zealand and Patagonia , while coho , sockeye and Atlantic salmon have been established in Patagonia, as well.     Both

2475-835: The Arctic Sea into the Pacific Ocean and the Sea of Okhotsk . It collides with the Kuroshio Current off the eastern shore of Japan to form the North Pacific Current (or Drift). The nutrient-rich Oyashio is named for its metaphorical role as the parent ( 親 , oya ) that provides for and nurtures marine organisms. The current has an important impact on the climate of the Russian Far East , mainly in Kamchatka and Chukotka , where

2550-708: The Limits of the Continental Shelf ruled in favor of the Russian Federation. Bowhead whales were first caught in 1847, and dominated the catch between 1852 and the late 1860s. Between 1850 and 1853 the majority of the fleet went to the Bering Strait region to hunt bowheads, but intense competition, poor ice conditions, and declining catches forced the fleet back to the Sea of Okhotsk. From 1854 to 1856, an average of over 160 vessels cruised in

2625-479: The North American West Coast salmon sport fishing has completely replaced inshore commercial salmon fishing. In most cases, the commercial value of a salmon sold as seafood can be several times less than the value attributed to the same fish caught by a sport fisherman. This is "a powerful economic argument for allocating stock resources preferentially to sport fishing". Salmon aquaculture

2700-452: The Oyashio Current also causes Vladivostok to be the most equatorward port to seasonally freeze and require icebreaking ships to remain open in winter. Nonetheless, this has relatively little effect on the fish yield through the Sea of Okhotsk, because the large tides mean freezing does not occur so easily. During glacial periods , when lower sea level exposed the Bering land bridge ,

2775-507: 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,

2850-498: The Pacific, carrying oxygen and nutrients, supporting abundant sea life. The Sea of Okhotsk has warmed in some places by as much as 3°C (5.4°F) since preindustrial times, three times faster than the global mean. Warming inhibits the formation of sea ice and also drives fish populations north. The salmon catch on the northern Japanese coast has fallen 70% in the last 15 years, while the Russian chum salmon catch has quadrupled. With

2925-513: The Sea of Okhotsk and is also known as the Okhotsk region ( オホーツク地方 , Ohōtsuku-chihō ) . Twenty-nine zones of possible oil and gas accumulation have been identified on the Sea of Okhotsk shelf, which runs along the coast. Total reserves are estimated at 3.5 billion tons of equivalent fuel, including 1.2 billion tons of oil and 1.5 billion cubic meters of gas. On 18 December 2011, the Russian oil drilling rig Kolskaya capsized and sank in

3000-701: The Southwest. The Northeastern and Northern limits on the Japan Sea [In La Perouse Strait (Sôya Kaikyô). A line joining Sôni Misaki and Nishi Notoro Misaki (45°55'N). From Cape Tuik (51°45'N) to Cape Sushcheva]. :: On the Southeast. A line running from Nosyappu Saki (Cape Noshap, 43°23'N) in the Island of Hokusyû (Yezo) through the Kuril or Tisima Islands to Cape Lopatka (South point of Kamchatka ) in such

3075-432: 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

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3150-608: The common name "salmon" simply due to similar shapes, behaviors and niches occupied: 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

3225-898: The current could not flow in the regions the Oyashio affects today. The level of cooling with the onset of glacial conditions (after an interglacial ) was much less than in other areas of the Earth at similar latitudes. This allowed Tōhoku and Hokkaidō – the only areas of East Asia with enough snowfall to potentially form glaciers – to remain unglaciated except at high elevations during periods when Europe and North America were largely glaciated. This lack of glaciation explains why, despite its present climate being much colder than most of Europe , East Asia has retained 96 percent of Pliocene tree genera, whereas Europe has retained only 27%. Sea of Okhotsk The Sea of Okhotsk covers an area of 1,583,000 square kilometres (611,000 sq mi), with

3300-430: 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

3375-472: 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: Beaver 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

3450-413: The entire coast of the sea, starting in 1733. Jean-François de Galaup, comte de Lapérouse and William Robert Broughton were the first non-Russian European navigators known to have passed through these waters other than Vries. Ivan Krusenstern explored the eastern coast of Sakhalin in 1805. Mamiya Rinzō and Gennady Nevelskoy determined that Sakhalin was indeed an island separated from the mainland by

3525-821: 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 . Salmon are mid- level carnivores whose diet change according to their life stage. Salmon fry predominantly feed upon zooplanktons until they reach fingerling sizes, when they start to consume more aquatic invertebrates such as insect larvae , micro crustaceans and worms . As juveniles (parrs), they become more predatory and actively prey upon aquatic insects , small crustaceans, tadpoles and small bait fishes . They are also known to breach

3600-491: The exception of Hokkaido , one of the Japanese home islands , the sea is surrounded on all sides by territory administered by the Russian Federation. South Sakhalin and the Kuril Islands were administered by Japan until 1945. Japan claims the southern Kuril Islands and refers to them as Northern Territories . The International Hydrographic Organization defines the limits of the Sea of Okhotsk as follows: :: On

3675-432: The fish return to the exact stream where they themselves hatched to spawn , and 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 are important food fish and are intensively farmed in many parts of

3750-443: The fish. There they deposit nutrient-rich urine and feces and partially eaten carcasses. Bears preparing for hibernation tend to preferentially consume the more nutrient- and energy -rich salmon roes and brain over the actual flesh , and are estimated to discard up to half the salmon they've harvested uneaten on the forest floor, in densities that can reach 4,000 kg (8,800 lb) per hectare, providing as much as 24% of

3825-566: The gills, which leads to large increases in their ability to secrete salt. Hormones involved in increasing salinity tolerance include insulin-like growth factor I , cortisol , and thyroid hormones , which permits the fish to endure the transition from a freshwater environment to 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

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3900-704: The lands surrounding the Sea of Okhotsk, as well as in northern Japan. Russian explorers Vassili Poyarkov (1639) and Ivan Moskvitin (1645) were the first Europeans to visit the Sea of Okhotsk (and, probably, the island of Sakhalin ) in the 1640s. The Dutch captain Maarten Gerritsz Vries in the Breskens entered the Sea of Okhotsk from the south-east in 1643, and charted parts of the Sakhalin coast and Kuril Islands, but failed to realize that either Sakhalin or Hokkaido are islands. During this period,

3975-684: 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

4050-458: 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

4125-411: The northern limit of tree growth is moved south up to ten degrees compared with the latitude it can reach in inland Siberia . The waters of the Oyashio Current form probably the richest fishery in the world owing to the extremely high nutrient content of the cold water and the very high tides (up to 10 metres (33 ft)) in some areas – which further enhances the availability of nutrients. However,

4200-446: 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

4275-526: 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

4350-408: 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

4425-466: 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. Farm-raised salmon are fed the carotenoids astaxanthin and canthaxanthin to match their flesh colour to wild salmon to improve their marketability. Wild salmon get these carotenoids , primarily astaxanthin, from eating shellfish and krill . One proposed alternative to

4500-407: 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

4575-509: 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 non-profit groups, such as

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4650-414: The sea each year. As catches declined between 1858 and 1860 the fleet shifted back to the Bering Strait region. The Russian military marine mammal program reportedly sources some of its animals from the Sea of Okhotsk. South Sakhalin was administered by Japan as Karafuto Prefecture from 1907 to 1949. The Kuril Islands were Japanese from 1855 and 1875 till the end of World War II in 1945. Afterward,

4725-409: The sea was sometimes known as the Sea of Kamchatka . The first and foremost Russian settlement on the shore was the port of Okhotsk , which relinquished commercial supremacy to Ayan in the 1840s. The Russian-American Company all but monopolized the commercial navigation of the sea in the first half of the 19th century. The Second Kamchatka Expedition under Vitus Bering systematically mapped

4800-421: 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

4875-546: 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

4950-458: The stream. Also, along with species like rainbow trout 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

5025-534: The survivability of other wild predatory fish which rely on them for food. Research is ongoing into sustainable and plant-based salmon feeds. Intensive salmon farming uses open-net cages, which have low production costs. It has the drawback of allowing disease and sea lice to spread to local wild salmon stocks. 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

5100-496: 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

5175-467: 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 the fished salmon. Beavers also function as ecosystem engineers; in the process of tree-cutting and damming , beavers alter the local ecosystems extensively. Beaver ponds can provide critical habitat for juvenile salmon . An example of this

5250-597: 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

5325-417: The water to attack terrestrial insects such as grasshoppers and dragonflies , as well as consuming fish eggs (even those of other salmon). As adults, salmon behave like other mid-sized pelagic fish , eating a variety of sea creatures including smaller forage fish such as lanternfish , herrings , sand lances , mackerels and barracudina . They also eat krill , squid and polychaete worms . In

5400-581: The world, with Norway being the world's largest producer of farmed salmon, followed by Chile . They are also highly prized game fish for recreational fishing , by both freshwater and saltwater anglers . Many species of salmon have since been introduced and naturalized into non-native environments such as the Great Lakes of North America , Patagonia in South America and South Island of New Zealand . The Modern English term salmon

5475-527: Was an area of open ocean at the center of the Sea of Okhotsk, about 55 km (30 mi) wide and 480 km (300 mi) long, that was surrounded by Russia's exclusive economic zone (EEZ). Since the Peanut Hole was not in the Russian EEZ, any country could fish there, and some began doing so in large numbers in 1991, catching perhaps as much as one million metric tons of pollock in 1992. This

5550-532: Was seen by the Russian Federation as presenting a danger to Russian fish stocks, since the fish move in and out of the Peanut Hole from the Russian EEZ. The Russian Federation petitioned the United Nations to declare the Peanut Hole to be part of Russia's continental shelf . In November 2013, a United Nations subcommittee accepted the Russian argument, and in March 2014 the full United Nations Commission on

5625-644: 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

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