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Lifespan, longevity, and ageing

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"Maximum longevity: 13 years (wild) Observations: Like in many other salmonid species, most animals die after spawning (Patnaik et al. 1994). While most animals return to spawn in rivers, however, there are alternative life histories: parr and jacks have a small body size and mature early, yet while jacks return early to spawn from the ocean, parr never migrate and can survive reproduction and breed again (Hutchings and Myers 1994). Unverified estimates suggest these animals may live up to 14 years (http://www.fishbase.org/).+p Interestingly, one study showed that animals infected with a Pearl mussel parasite live longer, have a lower cancer incidence, and avoid the typical "programmed death" that follows reproduction possibly because the parasite needs the salmon to live one more year to complete its life cycle (Ziuganov 2005)."
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Life Expectancy

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Range lifespan
Status: wild:
3 (high) years.

Average lifespan
Status: captivity:
3.3 years.

Average lifespan
Status: wild:
5.0 years.

Average lifespan
Status: wild:
13.0 years.

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Renzi, V. 1999. "Salmo salar" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Salmo_salar.html
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Vanessa Renzi, University of Michigan-Ann Arbor
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Habitat

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The Atlantic salmon is an anadromous species, living in fresh water for at least the first 2 or 3 years of life before migrating to sea. Relatively large cool rivers with extensive gravelly bottom headwaters are essential during their early life. Smolts migrate to sea where they may live for 1 or 2 years before returning to fresh water. The movements of Atlantic salmon at sea are not well understood. Tagging has shown that while some salmon wander, the great majority return to the river in which they were spawned. When at sea, salmon seem to prefer temperatures of 4 to 12 C. They may withstand exposure to temperatures in their lower lethal limit (-.7 C) and their upper lethal limit (27.8 C), but only for a short period of time (Bigelow, 1963).

Habitat Regions: temperate ; saltwater or marine ; freshwater

Aquatic Biomes: rivers and streams; coastal

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Renzi, V. 1999. "Salmo salar" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Salmo_salar.html
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Vanessa Renzi, University of Michigan-Ann Arbor
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Distribution

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The Atlantic salmon is native to the basin of the North Atlantic Ocean, from the Arctic Circle to Portugal in the eastern Atlantic, from Iceland and southern Greenland, and from the Ungava region of northern Quebec south to the Conneticut River (Scott and Crossman, 1973).

Biogeographic Regions: nearctic (Native ); palearctic (Native ); atlantic ocean (Native )

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Renzi, V. 1999. "Salmo salar" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Salmo_salar.html
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Vanessa Renzi, University of Michigan-Ann Arbor
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Trophic Strategy

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Young Atlantic salmon in streams eat mainly the larvae of aquatic insects such as blackflies, stoneflies, caddisflies, and chironomids. Terrestrial insects may also be important, especially in late summer. When at sea, salmon eat a variety of marine organisms. Plankton such as euphausiids are important food for pre-grisle but amphipods and decapods are also consumed. Larger salmon eat a variety of fishes such as herring and alewives, smelts, capelin, small mackerel, sand lace, and small cod. Prior to spawning, salmon cease to feed; they do not eat after they re-enter fresh water to spawn, despite their apparent willingness to take an artificial fly (Bigelow, 1963).

Animal Foods: fish; insects; aquatic crustaceans; other marine invertebrates; zooplankton

Primary Diet: carnivore (Piscivore , Insectivore , Eats non-insect arthropods)

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Renzi, V. 1999. "Salmo salar" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Salmo_salar.html
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Vanessa Renzi, University of Michigan-Ann Arbor
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Benefits

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The Atlantic salmon is renowned among game fishermen and is a highly prized food fish. Because of the strong market demand, an active aquaculture industry, which involves cage-rearing, hatcheries, and some sea ranching, has been developed all over the world. The commercial yield of the Atlantic salmon is estimated to be in the millions of dollars with expected annual doubling in the future (Scott and Crossman, 1973).

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Renzi, V. 1999. "Salmo salar" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Salmo_salar.html
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Vanessa Renzi, University of Michigan-Ann Arbor
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Life Cycle

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Hatching of the eggs usually occurs in April but the young remain in the gravel until the yolk sac is absorbed and finally emerge in May or June of the year following egg deposition. The newly hatched salmon, called "alevins," remain in rapid water until they are about 65mm long. The fish are now called "parr," and their growth is slow. Parr are called "smolts" when they reach a length of 12 to 15 cm and are ready to go to sea. Salmon grow rapidly while at sea. Some may return to the river to spawn after one year at sea, as "grilse," or may spend 2 years at sea, as "2 sea-year salmon" (Bigelow, 1963; Scott and Crossman, 1973).

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Renzi, V. 1999. "Salmo salar" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Salmo_salar.html
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Vanessa Renzi, University of Michigan-Ann Arbor
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Conservation Status

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North America's population of large salmon is at its lowest point in history. Declining numbers and loss of whole stocks in some rivers are causing increasing concern. Habitat destruction, denial of access to spawning grounds by dams and other obstructions, overfishing (including high-seas fishing and poaching), pollution, and especially acid rain are taking their toll. Cooperation and compromise by the major groups harvesting Atlantic salmon are essential if native stocks are to be saved. Scientific research has led to the creation of artificial spawning channels which provide a significant supplement to the production of salmon from natural streams. The Atlantic Salmon Federation is the largest, most effective organization devoted to the conservation of the Atlantic salmon and its habitat. This group has been successful in reducing commercial salmon fishing and some salmon streams have reported encouraging increases in the number of returning sea run fish as a result (Scott and Crossman, 1973; Atlantic Salmon Federation, 1996). Atlantic salmon are listed as lower risk by the IUCN, and they are considered an endangered species by the U.S. Fish and Wildlife Service.

US Federal List: endangered

CITES: no special status

State of Michigan List: no special status

IUCN Red List of Threatened Species: lower risk - least concern

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Renzi, V. 1999. "Salmo salar" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Salmo_salar.html
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Vanessa Renzi, University of Michigan-Ann Arbor
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Behavior

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Salmon have a great sense of smell, hearing, and taste which helps them find food and sense danger. Salmon are also able to sense danger by feeling the waves on their body.

Atlantic salmon also use their senses to find and return to their home river. Through imprinting, young fry memorize details about their home streams, and they use this knowledge as adult spawners to find their way back. Scientists are not exactly sure how salmon complete this feat, but some theories are the salmon use the sun and stars as navigational guides, while others claim these fish have stored the taste of their home water in their brain. Most feel that salmon are guided home by the characteristic odor of the parent stream which is imprinted during the smolts' migration (Maynor, 1996).

Communication Channels: visual ; tactile ; chemical

Perception Channels: visual ; tactile ; chemical

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Renzi, V. 1999. "Salmo salar" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Salmo_salar.html
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Vanessa Renzi, University of Michigan-Ann Arbor
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Untitled

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The major difference between Atlantic and Pacific salmon is that Atlantic salmon may spawn more than once while Pacific salmon die soon after one spawn. Long ago, some people made boots out of salmon skin!

The Atlantic salmon's sense of smell is 1000 times greater than that of a dog (Maynor, 1996).

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Renzi, V. 1999. "Salmo salar" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Salmo_salar.html
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Vanessa Renzi, University of Michigan-Ann Arbor
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Morphology

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Sea-run Atlantic salmon usually attain a larger size than do landlocked (those living in entirely fresh water) salmon. Sea-run salmon range from 2.3 to 9.1 kg and commercially caught fish average 4.5 to 5.4 kg. The world record rod-caught Atlantic salmon weighed 35.89 kg and was caught in the Tana River of Norway.

The adult Atlantic salmon is a graceful fish, deepening rearward from a small pointed head to the deepest point under the dorsal fin, then tapering to a slender caudal peduncle which supports a spreading and slightly emarginate caudal fin. Atlantic salmon are distinguished from the Pacific salmon because they have fewer than 13 rays in the anal fin. Their mouth is moderately large. The shape, length of head, and depth of body vary with each stage of sexual maturity.

Color varies with age of this fish. Small "parr," older young salmon, have 8 to 11 pigmented bars, or "parr marks," along each side of their body, alternating with a single row of red spots along the lateral line. These markings are lost when the "smolt" age is reached. Salmon in the sea are silvery on the sides and belly, while the back varies with shades of brown, green, and blue. Atlantic salmon also have numerous black spots, usually "X"-shaped and scattered around the body. When spawning, both sexes take on an overall bronze-purple coloration and may acquire reddish spots on the head and body. After spawning, the "kelts" are so dark in color that these fish are also called "black salmon"

(Eddy and Underhill, 1974; Bigelow, 1963; Scott and Crossman, 1973).

Range mass: 2.3 to 35.89 kg.

Other Physical Features: ectothermic ; heterothermic ; bilateral symmetry

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Renzi, V. 1999. "Salmo salar" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Salmo_salar.html
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Vanessa Renzi, University of Michigan-Ann Arbor
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Reproduction

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Atlantic salmon spawn in October and November, the peak of spawning usually occurring in late October. As spawning time nears, males undergo conspicuous changes in head shape: the head elongates and a pronounced hook, or kype, develops on the tip of the lower jaw. The nesting site is chosen by the female, usually a gravel-bottom riffle above a pool. The female digs the nest, called the "redd," by flapping strongly with her caudal fin and peduncle while on her side; the redd is formed by her generated water currents. The female rests freely during redd preparation while the male continues to court her and drive away other males. When the redd is finished, the male aligns himself next to the female, the eggs and sperm are released, and the eggs are fertilized during the intermingling of the gametes. On average, a female deposits 700-800 eggs per pound of her body weight. The eggs are pale orange in color, large and spherical, and somewhat adhesive for a short time. The female then covers the eggs with gravel, using the same method used to create the redd. The eggs are buried in gravel at a depth of about 12.7 to 25.4 cm.

The female rests after spawning and then repeats the operation, creating a new redd, depositing more eggs, and resting again until spawning is complete. The male continues to court and drive off intruders. Complete spawning by individuals may take a week or more, by which time the spawners are exhausted. Some Atlantic salmon die after spawning but many survive to spawn a second time; a very few salmon spawn three or more times.

Spawning completed, the fish, now called "kelts," may drop downriver to a pool and rest for a few weeks, or they may return at once to the ocean. Some may also remain in the river over winter and return to sea in the spring.

Hatching of the eggs usually occurs in April but the young remain in the gravel until the yolk sac is absorbed and finally emerge in May or June of the year following egg deposition. The newly hatched salmon, called "alevins," remain in rapid water until they are about 65mm long. The fish are now called "parr," and their growth is slow. Parr are called "smolts" when they reach a length of 12 to 15 cm and are ready to go to sea. Salmon grow rapidly while at sea. Some may return to the river to spawn after one year at sea, as "grilse," or may spend 2 years at sea, as "2 sea-year salmon" (Bigelow, 1963; Scott and Crossman, 1973).

Breeding interval: Breed once yearly, few breed twice before dying

Breeding season: October and November

Range age at sexual or reproductive maturity (female): 1 to 2 years.

Range age at sexual or reproductive maturity (male): 1 to 2 years.

Key Reproductive Features: seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization (External ); oviparous

There is no parental investment beyond spawning.

Parental Investment: pre-fertilization (Provisioning)

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Renzi, V. 1999. "Salmo salar" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Salmo_salar.html
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Vanessa Renzi, University of Michigan-Ann Arbor
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Biology

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Until the early 19th century the life cycle of the Atlantic salmon was not understood and juvenile stages were thought to be different species. Females dig a depression in the gravel into which eggs and sperm are released simultaneously. The first juvenile stage (alevins) hatch and remain in the gravel, feeding on yolk sacs that are attached to the body. The next stage (fry) feed on microscopic particles in the stream. When vertical markings appear on the young fish's body the juveniles are known as parr. This stage remains in the river for two to six years before they transform into 'smolt'. A silvery colouration develops and complex internal changes occur to allow survival in salt water. Adult Atlantic salmon spend most of their lives at sea where they roam vast distances in small groups in search of food. At sea their diet consists of squid, shrimp and small fish such as herring or cod. After one or more years the salmon return to their birthplace in order to spawn, and do not eat during this phase of their life cycle. It appears that an olfactory sense (sense of smell) enables the salmon to identify their exact natal location and they are able to leap vertical distances of up to an amazing 12 feet in their endeavour to return there.
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Conservation

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The North Atlantic Salmon Conservation Organisation was established in 1983 under the Convention for the Conservation of Salmon in the North Atlantic. It is an international organisation that aims to conserve and promote the rational management of salmon stocks in the wild. The organisation includes all countries in which the Atlantic salmon is historically found and many different measures have been taken to reduce exploitation and protect the salmon. However, numbers of salmon are not recovering and further research is being carried out into why this is the case.
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Description

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The Atlantic salmon, 'the leaper', has been called the king of fish, due primarily to their spectacular ability to clear seemingly insurmountable obstacles. Their large body is long and hydrodynamic and can measure up to 150 cm in length and weigh up to 39 kg. Adults are usually a silvery grey colour with some black spots but become more reddish with purple spots in the breeding season, and males develop a hooked lower jaw for fighting.
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Habitat

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Adult Atlantic salmon are found in the open ocean at depths between 2 to 10 metres. They return to freshwater to spawn in the streams in which they themselves were born, often only returning to pristine river systems. This makes them a useful indicator species of a river's quality.
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Range

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Historically the Atlantic salmon could be found throughout the North Atlantic in a range spreading from Quebec to Connecticut in the west and from the Arctic Circle to Portugal in the east. In the last 30 years however, the salmon population has suffered a devastating decline with catches falling by more than 80 percent. Today many populations are teetering on the brink of extinction or have already been lost, and it is believed that Atlantic salmon numbers are only reasonably healthy in four countries; Norway, Ireland, Iceland and Scotland. Across the UK, populations in nearly 50 percent of salmon rivers are at risk and over 30 percent are endangered.
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Status

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Classified as Lower Risk/least concern (LR/lc) on the IUCN Red List and listed on Appendix III of the Berne Convention. Freshwater populations are listed on Annex II of the EC Habitats Directive and Schedule 3 of the Conservation Regulations (1994).
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Threats

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The Atlantic salmon has shown a steady decline over the last two centuries, seemingly related to increased industrial development throughout their traditional home range. The situation has become drastically worse since the 1970s and catches of wild salmon have fallen by 80 percent. River pollution caused by industrialisation can severely damage local populations as can the increased number of man-made obstacles such as dams, weirs or the alteration of watercourses, which makes migration impossible. Salmon has become an extremely popular dish in the western world and commercial farming can affect wild populations in a number of ways; escaped salmon may erode the gene pool through interbreeding, or farms may act as foci for the spread of parasites and diseases to wild stocks.
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Brief Summary

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Salmon can grow very large: up to 1.5 meters long. They eat herring, smelt and crustaceans. The first years of life is spent in fresh water, after which they migrate to sea. After 1 to 3 years at sea, they migrate back to their place of birth to spawn. There is little known about where they stay at sea. From marked specimen, it appears that a large number of salmon migrate to waters around Greenland, thousands of kilometers from their spawning grounds.
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Large numbers of salmon are killed by parasites, finds new study

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On Phys.org:

The study, published today in Proceedings of the Royal Society B, involved experts at the University of St Andrews and is the first evidence of the full impact of sea lice on salmon mortality levels.

Read more at:http://phys.org/news/2012-11-large-salmon-parasites.html#jCp

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Seine River Benthopelagic Habitat

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This taxon is one of a number of benthopelagic species, whose habitat includes the Seine River system of Western Europe. Benthopelagic fish are found near the bottom of the water column, feeding on benthos and zooplankton The Marne and Yonne exhibit the greatest torrential flows, due to the percentage of their courses underlain by impermeable strata, in combination with the river gradients. Although the Loing manifests the highest percentage of impermeable strata of all the tributaries, its low gradient mitigates against torrential velocities. Thus the majority of the Seine and its tributaries exhibit a relaxed generally even flow rate. Seine water pollutant loads of heavy metals, nutrients, sediment and bacteria are relatively high, especially influnced by wastewater and surface runoff from Paris and its suburbs. Parisian pollutant loadings are noted to be particularly high during periods of high rainfall, not only due to high runoff, but also from the inadequate sewage treatment facilities in periods of high combined wastewater/stormwater flow. Heavy metal concentrations at Poses weir reveal the following levels: copper, 1.9 milligrams per liter; cadmium, 32 mg/l; and lead, 456 mg/l. Concentrations of zinc are also quite high, making the Seine Estuary one of the most highly contaminated estuaries in the world with respect especially to lead and cadmium. Significant amounts of toxic pollutants are also attached to sediments deposited in the Seine during the last two centuries, including mercury, nickel, chromium, toluene, DDT and a variety of herbicides and pesticides. Downriver from Paris, significant quantites of ammonium are discharged into the Seine from effluent of the Achères wastewater treatment plant. There are a total of 37 fish species inhabiting the Seine, and another two taxa that are known to have been extirpated in modern times. Two of the largest aquatic fauna known to have lived in the Seine are now locally extinct: the 500 centimeter (cm) long sturgeon (Acipenser sturio) and the 83 cm long allis shad (Alosa alosa). The largest bentho-pelagic species occurring in the Seine are: * the introduced 105 cm silver carp (Hypophthalmichthys molitrix); * the native 120 cm barbel (Hypophthalmichthys molitrix); * the native 150 cm Atlantic salmon (Salmo salar); and, * the native 500 cm Wels catfish (Silurus glanis).
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C.Michael Hogan. 2012. ''Seine River. Encyclopedia of Earth, National Council for Science and the Environment, Washington DC ed. Peter Saundry; ed.in-chief C.M.Hogan
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C. Michael Hogan (cmichaelhogan)
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Benefits

provided by FAO species catalogs
Caught by gillnets ("salmon fishing") and trawl nets. Also important for game fishing. The total catch reported for this species to FAO for 1999 was 4 287 t. The countries with the largest catches were Finland (914 t) and Ireland (511 t). Marketed fresh, dried/salted, smoked and frozen; eaten steamed, fried, broiled, microwaved and baked.

Brief Summary

provided by FAO species catalogs
Anadromous, adults in sea not forming shoals, making considerable migrations, often transatlantic (but life in sea not well known).Young remain in freshwater for 2-3 years, then migrate to the ocean for one or more years before returning to freshwater to spawn. Does not die after spawning but returns to the ocean. Active mainly during the day.Feeds at sea, crustaceans and small fishes (herring, sprat, sand-eels, capelin, small gadids); in freshwater, adults do not feed, but juveniles take mainly aquatic larvae of insects. Spawning runs April to August, the adults ascending far upstream, but not actually spawning until October-December at 5-6 years of age.

Size

provided by FAO species catalogs
To about 150 cm and 39 kg or more; usually 40-130 cm.

Distribution

provided by FAO species catalogs
Atlantic coasts of Europe, from Barents Sea, northern Norway and Baltic southward to northern Portugal, also around Iceland and southern Greenland; not in Mediterranean. Elsewhere, coasts of Canada and North America.

Diagnostic Description

provided by FAO species catalogs
Body elongate, but becoming deeper with age, caudal peduncle slender, the fish easily grasped by it. Tip of upper jaw reaching to hind margin of eye, but not beyond; jaws in adult males become greatly hooked just before and during breeding. A staggered line of teeth on shaft of vomer, but none on head of vomer. Gillrakers 17-24. Dorsal finrays iii-iv + 9-12, and an adipose fin behind it; pelvic finray i-ii (7) 8-9, base below latter half of dorsal fin. Anal finrays iii-iv + 7-9 (10). Caudal fin fairly deeply forked. Scales small, 114-130 in lateral line, 11-15 obliquely from adipose fin to lateral line. Vertebrae 59-60. Colour back brown, or green/blue, flanks silvery, belly white; back and flanks above lateral line (rarely below it) with X-shaped black spots; in freshwater, flanks greenish or brown, mottled with red or orange and with large dark spots with lighter edges.

References

  • Alegre, M., J. Lleonart & J. Veny. - 1992Espècies Pesqueres d'interès comercial. Nomenclatura oficial catalana. Generalitat de Catalunya. Departament de Cultura, DARP, TERMCAT. 64 pp.
  • Froese, R. and D. Pauly. Editors. 2003. FishBase. World Wide Web electronic publication. www.fishbase.org
  • Scott, W.B. & E.J. Crossman. - 1973Freshwater Fishes of Canada. Fisheries Research Board of Canada, Bulletin 184: 966 pp.
  • Svetovidov, A.N. - 1973 Salmonidae. In: J. C. Hureau & Th. Monod (eds.). Check-list of the fishes of the north-eastern Atlantic and of the Mediterranean (CLOFNAM). Unesco, Paris. Vol. I: 145-151.
  • Svetovidov, A.N. - 1984 Salmonidae. In: P.J.P. Whitehead et al., (eds.). Fishes of the North-eastern Atlantic and the Mediterranean (FNAM). Unesco, Paris, vol. I: 373-385.
  • Wheeler, A. - 1978Key to the Fishes of Northern Europe. A guide to the identification of more than 350 species. Frederick Warne (Publishers) Ltd., London. 380 pp.

Diagnostic Description

provided by Fishbase
Distinguished from congeners by having the following unique characters: 10-13 scales between end of adipose base and lateral line; 17-24 gill rakers (Ref. 59043); caudal fin deeply forked in individuals smaller than 20 cm SL; hyaline or grey adipose margin; posterior part of vomer toothless (Ref. 59043). Mouth extends only to area below rear of eye and has well developed teeth (Ref. 51442). Vomerine teeth weak (Ref. 7251). Caudal fin with 19 rays (Ref. 2196). Little scales (Ref. 51442). Juveniles have 8-12 blue-violet spots on the flanks with little red spots in-between (Ref. 51442). Adults at sea are bluish-green dorsally becoming silvery along the sides and white ventrally; with a few black spots but none under lateral line (Ref. 37032, Ref. 51442). Caudal fin usually unspotted and adipose fin not black bordered. During reproduction individuals lose the silvery shine and become dull brown or yellowish. Males may be mottled with red or have large black patches (Refs. 37032, 51442, 88171). Skin becomes thick and leathery. Survivors lose their spawning coloration and are generally dark in colour (Ref. 84357). During the spawning season, males are characterized by elongated hooked jaws that meet at the tips, thicker fins, and slime covering their body. Hook of males dwindle after spawning (Ref. 35388).
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Trophic Strategy

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Juveniles feed mainly on aquatic insects and crustaceans. At sea the Atlantic salmon is pelagic, usually found feeding near the surface (Ref. 59043) preying on fish and crustaceans (Ref. 35387). May make long distance feeding migrations while at sea (e.g. individuals from European rivers may migrate to rich feeding grounds around the Faeroes Islands and in western Greenland (Ref. 58137)). Adults do not feed in freshwater during the spawning and post-spawning migrations (Refs. 30578, 51442, 59043). Preyed upon by American mergansers, kingfishers, harbor seals, grey seals, sharks, pollock and tuna.
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Morphology

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Dorsal spines (total): 3 - 4; Dorsal soft rays (total): 9 - 15; Anal spines: 3 - 4; Analsoft rays: 7 - 11; Vertebrae: 58 - 61
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Migration

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Anadromous. Fish that ascend rivers to spawn, as salmon and hilsa do. Sub-division of diadromous. Migrations should be cyclical and predictable and cover more than 100 km.
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Life Cycle

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At the onset of sexual maturity this species is known to return from the ocean to the river where it was born, and even to its specific natal site (Refs. 7471, 51442). Lacustrine populations move to tributaries (Ref. 59043). Spawning migration into freshwater lasts from June to November. Spawns at 6-10°C (Ref. 89464) in gravel river areas far upstream with moderate to fast-flowing, well-oxygenated waters and a succession of riffles and pools (Refs. 6390, 59043). The female selects a site where the gravel is of the right size and of sufficient depth (0.1 to 0.3 m) (Refs. 7471, 51442) and water depth is around 0.5-3 m (Ref. 35387). The female digs a depression ("redd") by turning on her side and flexing her body up and down, without touching the stones (Ref. 36794). This species spawns in pairs. The male guards and defends the female against other males (Ref. 59043). A female releases between 8,000-25,000 eggs during a spawning season (Ref. 7471, 88187); 500 to 2000 per kg (Ref. 51442). Fertilized eggs sink into the redd and are covered with a layer of gravel (0.1-0.3 m) usually by the male (Refs. 7471, 59043). Females are also observed to cover the eggs. Individual spawning is completed in 2-3 days (Ref. 7471) after a female digging several redds and spawning with several males. Period of spawning lasts for 1-2 weeks. Most males die after spawning, while 10-40% of females may survive and return to the sea in autumn or overwinter in rivers, feed one summer, and migrate again. They may spawn in the year following the first reproduction or may remain at sea for 18 months before returning once more to the river. Of the returning females, about 0.3-6 % spawn a second time and very few spawn a third or fourth time. In short rivers with presumably less exhaustive upstream migration, up to 34% of returning individuals spawn a second time; some individuals may spawn for up to six seasons (Ref. 59043). Eggs hatch in spring, usually after 70-160 days (Ref. 59043). Upon hatching, alevins (i.e. newly-hatched young up to 1 month) are negatively phototactic and move deeper into the gravel (Refs. 58137, 59043). As their yolk sac is absorbed, the fry emerge from the bottom and move to shallow riffles just downstream of their redd (Ref. 59043). Mortality of young individuals during the first months may range from 14-61 % (Ref. 89465). Parr (i.e. juveniles) may remain in freshwater environments for 1-7 years (depending on temperature and feeding conditions) but most stay for 2-3 years. Parr undergo morphological and physiological changes called smoltification which prepares them for life in the sea. At the southern end of their range, many reach a length of 12-15 cm, transform into smolts and are ready for migration in spring of the first year after hatching (Refs. 7471, 51442). At the northern end of the range they may take 5-6 years to reach smolt stage (Ref. 36794). Smolts move towards estuaries, the continental shelf and eventually the open ocean (Ref. 89462). The Atlantic salmon matures between 3-7 years (Ref. 41851). After 1-4 years at sea, it migrates back to the upper reaches of its natal river to spawn (Refs. 59043, 89461). It has an acute sense of smell and it is suggested that it imprints a sequence of odours while inhabiting rivers and during its smolt run. It presumably reverses this sequence to return to its natal site (Ref. 89461). Several studies have shown that smolt runs are strongly correlated to increasing water temperature and water flow during spring (Ref. 89461).There is little evidence of natural spawning by land-locked populations of Atlantic salmon in Australia, and populations are maintained by stocking (Ref. 6390, 26519).
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Rainer Froese
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Diseases and Parasites

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Edwardsiellosis. Bacterial diseases
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Allan Palacio
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Diseases and Parasites

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Epitheliocystis. Bacterial diseases
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Diseases and Parasites

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Enteric Redmouth Disease. Bacterial diseases
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Biology

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Amphihaline species, spending most of its life in freshwater (Ref. 51442). Occurs in lakes and rocky runs and pools of small to large rivers (Ref. 86798). Some landlocked populations exist. Found in all rivers where temperature rises above 10° C for about 3 months per year and does not exceed 20° C for more than a few weeks in summer (Ref. 59043) (preferred temperatures 4-12°C). Juveniles may live in cold lakes in northern Europe (Ref. 59043). Parr (i.e. juveniles) are territorial and are found in the upper reaches of rivers and streams, in riffle areas with strong current and rough gravel bottoms (Ref. 7471). During winter, parr seek refuge in small spaces or under stones during the day (Refs. 59043, 89461). Young remain in freshwater for 1 to 6 years, then migrate to coastal marine waters or even to open oceans where they remain for 1 to 4 years before returning to freshwater for spawning (Ref. 51442). Adults inhabit cooler waters with strong to moderate flow (Ref. 44894). The Atlantic salmon is reported to live up to 10 years, but most individuals only reach 4-6 years (Ref. 88187). Juveniles feed mainly on aquatic insects, mollusks, crustaceans and fish; adults at sea feed on squids, shrimps, and fish (Ref. 51442). Most populations depend mostly or exclusively on stocking due to degradations of environmental conditions. Fishing pressure on wild stocks has decreased due to intensive farming but other problems have increased. Farmed salmons escape in large numbers and move to any river and hybridize with wild stocks (Ref. 59043). This species may hybridize with trout (Salmo trutta) (Ref. 59043). Diseases of the species include furunculosis (Aeromonas salmonicida), corynebacterial kidney disease (Renibacterium salmoninarum), enteric red mouth disease (Yersinia ruckeri), infectious pancreatic necrosis virus, bacterial kidney disease, fin rot and fungus infections (Ref. 5951). Marketed fresh, dried or salted, smoked, and frozen; eaten steamed, fried, broiled, cooked in microwave, and baked (Ref. 9988).
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Importance

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fisheries: highly commercial; aquaculture: commercial; gamefish: yes; price category: very high; price reliability: reliable: based on ex-vessel price for this species
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Atlantic salmon

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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 found in the northern Atlantic Ocean and in rivers that flow into it. Most populations are anadromous, hatching in streams and rivers but moving out to sea as they grow where they mature, after which the adults seasonally move upstream again to spawn.[2]

When the mature fish re-enter rivers to spawn, they change in colour and appearance. Some populations of this fish only migrate to large lakes, and are "landlocked", spending their entire lives in freshwater. Such populations are found throughout the range of the species. Unlike Pacific species of salmon, S. salar is iteroparous, which means it can survive spawning and return to sea to repeat the process again in another year with 5-10% returning to the sea to spawn again. Such individuals can grow to extremely large sizes, although they are rare. The different life stages of the fish are known by many different names in English: alevin, fry, parr and smolt.

Atlantic salmon is considered a very healthy food and one of the fish with a more refined taste in many cultures. As such it features in numerous popular traditional cuisines and can fetch a higher price than some other fish. It has thus long been the target of recreational and commercial fishing, and this, as well as habitat destruction, has impacted the population in some areas. As a result, the species is the subject of conservation efforts in several countries, which appear to have been somewhat successful since the 2000s. Techniques to farm this species using aquacultural methods have also been developed, and at present it is farmed in great numbers in many places around the world. Although this is now a viable alternative to wild-caught fish, farming methods have attracted criticism from environmentalists.

Nomenclature

The Atlantic salmon was given its scientific binomial name by Swedish zoologist and taxonomist Carl Linnaeus in 1758. The name, Salmo salar, derives from the Latin salmo, meaning salmon, and salar, meaning leaper, according to M. Barton,[3] but more likely meaning "resident of salt water". Lewis and Short's Latin Dictionary (Clarendon Press, Oxford, 1879) translates salar as a kind of trout from its use in the Idylls of the poet Ausonius (4th century CE). Later, the differently coloured smolts were found to be the same species.

Other names used for the Atlantic salmon are: bay salmon, black salmon, caplin-scull salmon, fiddler, sebago salmon, silver salmon, outside salmon and winnish. At different points in their maturation and life cycle, they are known as parr, smolt, grilse, grilt, kelt, slink, and spring salmon. Atlantic salmon that do not journey to sea are known as landlocked salmon (or ouananiche in North America).[4]

Description

Atlantic salmon are among the largest salmon species

Atlantic salmon are the largest species in their genus, Salmo. After two years at sea, the fish average 71 to 76 cm (28 to 30 in) in length and 3.6 to 5.4 kg (7.9 to 11.9 lb) in weight.[5] But specimens that spend four or more winters feeding at sea can be much larger. An Atlantic salmon netted in 1960 in Scotland, in the estuary of the river Hope, weighed 49.44 kg (109.0 lb), the heaviest recorded in all available literature. Another netted in 1925 in Norway measured 160.65 cm (63.25 in) in length, the longest Atlantic salmon on record.[6]

The colouration of young Atlantic salmon does not resemble the adult stage. While they live in fresh water, they have blue and red spots. At maturity, they take on a silver-blue sheen. The easiest way of identifying them as an adult is by the black spots predominantly above the lateral line, though the caudal fin is usually unspotted. When they reproduce, males take on a slight green or red colouration. The salmon has a fusiform body, and well-developed teeth. All fins, except the adipose fin, are bordered with black.

Distribution and habitat

Ocean migration of Atlantic salmon[7]

The natural breeding grounds of Atlantic salmon are rivers in Europe and the northeastern coast of North America. In Europe, Atlantic salmon are still found as far south as Spain, and as far north as Russia. Because of sport-fishing, some of the species' southern populations in northern Spain are growing smaller.[8] The species distribution is easily influenced by changes in freshwater habitat and climate. Atlantic salmon are a cold-water fish species and are particularly sensitive to changes in water temperature.

The Housatonic River, and its Naugatuck River tributary, hosted the southernmost Atlantic salmon spawning runs in the United States.[9][10] However, there is a 1609 account by Henry Hudson that Atlantic salmon once ran up the Hudson River.[11] In addition, fish scale evidence dating to 10,000 years BP places Atlantic salmon in a coastal New Jersey pond.[12]

Two publications from 1988 and 1996 questioned the notion that Atlantic salmon were prehistorically plentiful in New England, when the climate was warmer as it is now. This argument was primarily based on a paucity of bone data in archaeological sites relative to other fish species, and the assertion that historical claims of abundance may have been exaggerated.[13][14] This argument was later challenged in another paper which claimed that lack of archaeological bone fragments could be explained by salmon bones being rare at sites that still have large salmon runs and that salmonid bones in general are poorly recovered relative to other fish species.[15][16]

Atlantic salmon populations were significantly reduced in the United States following European settlement. The fur trade, timber harvesting, dams and mills and agriculture degraded freshwater habitats and lowered the carrying capacity of most North American streams. Beaver populations were trapped to near-extinction by 1800, and log drives and clear-cutting further exacerbated stream erosion and habitat loss. As timber and fur gave way to agriculture, freshwater Atlantic salmon habitat was further compromised. According to historian D.W. Dunfield (1985) "over half of the historical Atlantic salmon runs had been lost in North America by 1850". As early as 1798, a bill for the preservation of Atlantic Salmon was introduced in Canadian Parliament, to protect populations in Lake Ontario.[17] In the Gulf Region of Nova Scotia it was reported that 31 of the 33 Atlantic salmon streams were blocked off by lumber dams, leading to the extirpation of early-run fish in many watersheds. The inshore Atlantic salmon fishery became a major export of the New World, with major fishing operations establishing along the shores of major river systems. The southernmost populations were the first to disappear.

Young salmon spend one to four years in their natal river. When they are large enough (c. 15 centimetres (5.9 in)), they smoltify, changing camouflage from stream-adapted with large, gray spots to sea-adapted with shiny sides. They also undergo some endocrinological changes to adapt to osmotic differences between fresh water and seawater habitat. When smoltification is complete, the parr (young fish) now begin to swim with the current instead of against it. With this behavioral change, the fish are now referred to as smolt. When the smolt reach the sea, they follow sea surface currents and feed on plankton or fry from other fish species such as herring. During their time at sea, they can sense the change in the Earth magnetic field through iron in their lateral line.

When they have had a year of good growth, they will move to the sea surface currents that transport them back to their natal river. It is a major misconception that salmon swim thousands of kilometres at sea; instead they surf through sea surface currents. It is possible they find their natal river by smell, although this is not confirmed;[18] only 5% of Atlantic salmon go up the wrong river. The range of an individual Atlantic salmon can thus be the river where they are born and the sea surface currents that are connected to that river in a circular path.

Wild salmon continued to disappear from many rivers during the twentieth century due to overfishing and habitat change.[18]

Ecology

Diet

Young salmon begin a feeding response within a few days. After the yolk sac is absorbed by the body, they begin to hunt. Juveniles start with tiny invertebrates, but as they mature, they may occasionally eat small fish. During this time, they hunt both in the substrate and in the current. Some have been known to eat salmon eggs. Plankton such as euphausiids are important food for pre-grilse but amphipods and decapods are also consumed.[19] The most commonly eaten foods include caddisflies, blackflies, mayflies, stoneflies,[18] and chironomids, as well as terrestrial insects.[19]

As adults, the salmon prefer capelin as their meal of choice. Capelin are elongated silvery fish that grow up to 20–25 centimetres (8–10 in) long.[20] Other fish consumed include herring, alewives, smelts, scomberids, sand lance, and small cod.[19]

Behavior

Fry and parr have been said to be territorial, but evidence showing them to guard territories is inconclusive. While they may occasionally be aggressive towards each other, the social hierarchy is still unclear. Many have been found to school, especially when leaving the estuary.

Adult Atlantic salmon are considered much more aggressive than other salmon, and are more likely to attack other fish than others.[18]

Life stages

Life cycle of the Atlantic salmon

Most Atlantic salmon follow an anadromous migration pattern,[2] in that they undergo their greatest feeding and growth in saltwater; however, adults return to spawn in native freshwater streams where the eggs hatch and juveniles grow through several distinct stages.

Atlantic salmon do not require saltwater. Numerous examples of fully freshwater (i.e., "landlocked") populations of the species exist throughout the Northern Hemisphere,[2] including a now extinct population in Lake Ontario, which have been shown in recent studies to have spent their entire life cycle in watershed of the lake.[21] In North America, the landlocked strains are frequently known as ouananiche.

Freshwater phase

The freshwater phases of Atlantic salmon vary between two and eight years, according to river location.[22] While the young in southern rivers, such as those to the English Channel, are only one year old when they leave, those further north, such as in Scottish rivers, can be over four years old, and in Ungava Bay, northern Quebec, smolts as old as eight years have been encountered.[22]

The first phase is the alevin stage, when the fish stay in the breeding ground and use the remaining nutrients in their yolk sacs. During this developmental stage, their young gills develop and they become active hunters. Next is the fry stage, where the fish grow and subsequently leave the breeding ground in search of food. During this time, they move to areas with higher prey concentration. The final freshwater stage is when they develop into parr, in which they prepare for the trek to the Atlantic Ocean.

During these times, the Atlantic salmon are very susceptible to predation. Nearly 40% are eaten by trout alone. Other predators include other fish and birds. Egg and juvenile survival is dependent on habitat quality as Atlantic salmon are sensitive to ecological change.

Saltwater phases

When parr develop into smolt, they begin the trip to the ocean, which predominantly happens between March and June. Migration allows acclimation to the changing salinity. Once ready, young smolt leave, preferring an ebb tide.

Having left their natal streams, they experience a period of rapid growth during the one to four years they live in the ocean. Typically, Atlantic salmon migrate from their home streams to an area on the continental plate off West Greenland. During this time, they face predation from humans, seals, Greenland sharks, skate, cod, and halibut. Some dolphins have been noticed playing with dead salmon, but it is still unclear whether they consume them.

Once large enough, Atlantic salmon change into the grilse phase, when they become ready to return to the same freshwater tributary they departed from as smolts. After returning to their natal streams, the salmon will cease eating altogether prior to spawning. Although largely unknown, odor – the exact chemical signature of that stream – may play an important role in how salmon return to the area where they hatched. Once heavier than about 250 g, the fish no longer become prey for birds and many fish, although seals do prey upon them. Grey and common seals commonly eat Atlantic salmon. Survivability to this stage has been estimated at between 14 and 53%.[18]

Breeding

Fish ladder for Atlantic salmon constructed to allow Atlantic salmon and Sea-trout to navigate over a weir

Atlantic salmon breed in the rivers of Western Europe from northern Portugal north to Norway, Iceland, and Greenland, and the east coast of North America from Connecticut in the United States north to northern Labrador and Arctic Canada.

The species constructs a nest or "redd" in the gravel bed of a stream. The female creates a powerful downdraught of water with her tail near the gravel to excavate a depression. After she and a male fish have eggs and milt (sperm), respectively, upstream of the depression, the female again uses her tail, this time to shift gravel to cover the eggs and milt which have lodged in the depression.

Unlike the various Pacific salmon species which die after spawning (semelparous), the Atlantic salmon is iteroparous, which means the fish may recondition themselves and return to the sea to repeat the migration and spawning pattern several times, although most spawn only once or twice.[2][23] Migration and spawning exact an enormous physiological toll on individuals, such that repeat spawners are the exception rather than the norm.[23] Atlantic salmon show high diversity in age of maturity and may mature as parr, one- to five-sea-winter fish, and in rare instances, at older sea ages. This variety of ages can occur in the same population, constituting a 'bet hedging' strategy against variation in stream flows. So in a drought year, some fish of a given age will not return to spawn, allowing that generation other, wetter years in which to spawn.[22]

Hybridization

When in shared breeding habitats, Atlantic salmon will hybridize with brown trout (Salmo trutta).[24][25][26] Hybrids between Atlantic salmon and brown trout were detected in two of four watersheds studied in northern Spain. The proportions of hybrids in samples of salmon ranged from 0 to 7-7% but these proportions were not significantly homogeneous among locations, resulting in a mean hybridization rate of 2-3%. This is the highest rate of natural hybridization so far reported and is significantly greater than rates observed elsewhere in Europe.[27]

Beaver impact

The decline in anadromous salmonid species over the last two to three centuries is correlated with the decline in the North American beaver and European beaver, although some fish and game departments continue to advocate removal of beaver dams as potential barriers to spawning runs. Migration of adult Atlantic salmon may be limited by beaver dams during periods of low stream flows, but the presence of juvenile salmon upstream of the dams suggests they are penetrated by parr.[28] Downstream migration of Atlantic salmon smolts was similarly unaffected by beaver dams, even in periods of low flows.[28]

In a 2003 study, Atlantic salmon and sea-run brown trout spawning in the Numedalslågen River and 51 of its tributaries in southeastern Norway was unhindered by beavers.[29] In a restored, third-order stream in northern Nova Scotia, beaver dams generally posed no barrier to Atlantic salmon migration except in the smallest upstream reaches in years of low flow where pools were not deep enough to enable the fish to leap the dam or without a column of water over-topping the dam for the fish to swim up.[30]

The importance of winter habitat to salmonids afforded by beaver ponds may be especially important in streams of northerly latitudes without deep pools where ice cover makes contact with the bottom of shallow streams.[28] In addition, the up to eight-year-long residence time of juveniles in freshwater may make beaver-created permanent summer pools a crucial success factor for Atlantic salmon populations. In fact, two-year-old Atlantic salmon parr in beaver ponds in eastern Canada showed faster summer growth in length and mass and were in better condition than parr upstream or downstream from the pond.[31]

Relationship to humans

Atlantic salmon is a popular fish for human consumption[2] and is commonly sold fresh, canned, or frozen.

Seine fishing for salmon – Wenzel Hollar, 1607–1677

Wood and stone weirs along streams and ponds were used for millennia to harvest salmon in the rivers of New England.[32] European fishermen gillnetted for Atlantic salmon in rivers using hand-made nets for many centuries[33] and gillnetting was also used in early colonial America.[34]

In its natal streams, Atlantic salmon are considered prized recreational fish, pursued by fly anglers during its annual runs. At one time, the species supported an important commercial fishery, but having become endangered throughout its range globally, wild-caught Atlantic salmon are now virtually absent from the market.[35] Instead, nearly all are from aquaculture farms, predominantly in Norway, Chile, Canada, the UK, Ireland, Faroe Islands, Russia and Tasmania in Australia.[23]

Aquaculture

Atlantic salmon marine cages in the Faroe Islands

Adult male and female fish are anaesthetised; their eggs and sperm are "stripped" after the fish are cleaned and cloth dried. Sperm and eggs are mixed, washed, and placed into freshwater. Adults recover in flowing, clean, well-aerated water.[36] Some researchers have even studied cryopreservation of their eggs.[37]

Fry are generally reared in large freshwater tanks for 12 to 20 months. Once the fish have reached the smolt phase, they are taken out to sea, where they are held for up to two years. During this time, the fish grow and mature in large cages off the coasts of Canada, the US, or parts of Europe.[23]

There are many different commercially available cage designs built to operate in a wide variety of aquatic conditions. High-density polyethylene (HDPE) cages are widely used, with HDPE pipes forming a floating collar ring onto which the fish net pen is secured and suspended in the water below.[38]

Advancements in cage technologies have allowed for reduction in fish escapes, improvement in growing conditions, and maximization of aquaculture production volume per unit area of growing space.[38]

Controversy

Farmed Atlantic salmon are known to occasionally escape from cages and enter the habitat of wild populations. Interbreeding between escaped farm fish and wild fish decreases genetic diversity and introduces "the potential to genetically alter native populations, reduce local adaptation and negatively affect population viability and character".[39] A study in 2000 demonstrated that the genes of farmed Atlantic salmon intrude wild populations mainly through wild males breeding with farmed females, though farmed specimens showed reduced capacity for breeding success overall compared to their wild counterparts.[40] Further study in 2018 discovered extensive cross-breeding of wild and farmed Atlantic salmon in the Northwest Atlantic, showing that 27.1% of fish in 17 out of 18 rivers examined are artificially stocked or hybrids. Farming of Atlantic salmon in open cages at sea has also been linked, at least in part, to a decline in wild stocks attributed to the passing of parasites from farmed to wild individuals.[41]

On the west coast of the United States and Canada, aquaculturists are generally under scrutiny to ensure that non-native Atlantic salmon cannot escape from their open-net pens, however occasional incidents of escape have been documented.[42] During one incident in 2017, for example, up to 300,000 potentially invasive Atlantic salmon escaped a farm among the San Juan Islands in Puget Sound, Washington.[43] Washington went on in 2019 to implement a gradual phase out of salmon farming to be completed by 2025.[44]

Despite being the source of considerable controversy,[45] the likelihood of escaped Atlantic salmon establishing an invasive presence in the Pacific Northwest is considered minimal, largely because a number of 20th century efforts aimed at deliberately introducing them to the region were ultimately unsuccessful.[46] From 1905 until 1935, for example, in excess of 8.6 million Atlantic salmon of various life stages (predominantly advanced fry) were intentionally introduced to more than 60 individual British Columbia lakes and streams. Historical records indicate, in a few instances, mature sea-run Atlantic salmon were captured in the Cowichan River; however, a self-sustaining population never materialized. Similarly unsuccessful results were realized after deliberate attempts at introduction by Washington as late as the 1980s.[47] Consequently, environmental assessments by the US National Marine Fisheries Service (NMFS), the Washington Department of Fish and Wildlife and the BC Environmental Assessment Office have concluded the potential risk of Atlantic salmon colonization in the Pacific Northwest is low.[48]

Future prospects

A study of Næve et al. (2022) estimated the impact of 50 years of genetic selection and tried to predict the impact it could have until 2050. In order to do this, a common garden experiment was used to model and simulate past and future effects for 11 generations of genetic selection of increased growth rate in Atlantic salmon. To model the contribution that breeding has made in the industry from generation 0 (harvested in 1975– 1978) to generation 11 (harvested in 2017 – 2019), and to simulate growth until 2050 (generation 24), the Norwegian salmon aquaculture production between 2016 and 2019 was used as a base case. The simulation of the expected growth until 2050 (generation 24) gave five different scenarios : Historical (H1), Forecast 1 (F1), Forecast 2 (F2), Forecast 3 (F3) and Forecast 4 (F4). Changes in thermal growth coefficient (TGC) per generation were used in the model to simulate the differences in the five scenarios. The genetic data, H1, and the most conservative forecast scenario, F1, simulate what can be expected in 2050 if the trend from generation 0 through 11 is maintained. The following forecast scenarios assume a greater increase in genetic growth with a larger increase in the TGC in the generations to come. In the next two generations, more advanced selection methods such as marker assisted selection (from generation 10) and genomic selection (from generation 11) were implemented. This resulted in increased gain in selection for growth and simulated F2 and F3. The most progressive scenario, F4, aimed at exploring the effect in the industry when the full genetic potential is utilized. This assumes a further development of advanced techniques in the years to come. The authors of the article found that the daily yield of the biomass increased with increasing generations in the historic and forecast scenarios. Further, the production time in seawater to reach the harvest weight of 5100 g is expected to be reduced by 53% in 2050. When production time can be reduced, this will also reduce e.g. time at risk of diseases. In the most progressive scenario, mortality in seawater was expected to be reduced by up to 50%. Further, the authors found that production per license can increase by up to 121%. Additionally, 77% of the new volume needed to achieve five million tonnes in 2050, may be provided by genomic selection. However, one should keep in mind that this article was published by the firm Aquagen, and can possibly be biased and too optimistic. [49]

Conservation

The IUCN rates this as a common species with a conservation status of "least concern", however it has been 25 years since the IUCN has released this status.[50][51] A more recent regional assessment revealed that the European population of this species is vulnerable, and this might be the same or a similar status globally. Location-specific assessments have shown population declines across parts of the Atlantic Salmon's natural range, with populations along the coast of Maine and the Inner Bay of Fundy now listed as "endangered" under the Endangered Species Act, and the Canadian Species at Risk Act, respectively.[52][50]

Human activities have impacted salmon populations across parts of its range. The major threats are from overfishing and habitat change.[17] Salmon decline in Lake Ontario goes back to the 18th–19th centuries, due to logging and soil erosion, as well as dam and mill construction. By 1896, the species was declared extirpated from the lake.[21][53]

In the 1950s, salmon from rivers in the United States and Canada, as well as from Europe, were discovered to gather in the sea around Greenland and the Faroe Islands. A commercial fishing industry was established, taking salmon using drift nets. After an initial series of record annual catches, the numbers crashed; between 1979 and 1990, catches fell from four million to 700,000.[54]

A man fishing for Atlantic salmon in the Pabos River of Quebec as recreation.

Beginning around 1990, the rates of Atlantic salmon mortality at sea more than doubled in the western Atlantic. Rivers of the coast of Maine, southern New Brunswick and much of mainland Nova Scotia saw runs drop precipitously, and even disappear. An international effort to study the increased mortality rate was organized by the North Atlantic Salmon Conservation Organization.[4] In 2000 the numbers of Atlantic salmon dropped to very low levels in Newfoundland, Canada.[55] In 2007 at least one sport fishing organization from Iceland and Scandinavia blamed less fish caught by recreational anglers on overfishing at sea, and thus created the North Atlantic Salmon Fund to buy commercial quotas in the Atlantic from commercial fishermen in an effort to preserve wild Salmo salar stocks.[54]

Possibly because of improvements in ocean feeding grounds, returns in 2008 were very positive. On the Penobscot River in Maine, returns were about 940 in 2007, and by mid-July 2008, the return was 1,938. Similar stories were reported in rivers from Newfoundland to Quebec. In 2011, more than 3,100 salmon returned to the Penobscot, the most since 1986, and nearly 200 ascended the Narraguagus River, up from the low two digits just a decade before.[4][56]

Recreational fishing of stocked, landlocked Atlantic salmon is now authorized in much of the US and Canada where it occurs in large numbers, but this is subject to regulations in many states or provinces which are designed to maintain the continuity of the species. Strict catch limits, catch and release practices and forced fly fishing are examples of those regulations.[57][58] However, catch and release angling can be an additional stressor on Atlantic salmon populations, especially when its impacts are combined with the existing pressures of climate change, overfishing, and predation.[59][57]

Restoration efforts

A fishmonger in Lysekil, Sweden shows a Norwegian salmon.

Around the North Atlantic, efforts to restore salmon to their native habitats are underway, with slow progress. Habitat restoration and protection are key to this process, but issues of excessive harvest and competition with farmed and escaped salmon are also primary considerations. In the Great Lakes, Atlantic salmon have been reintroduced, but the percentage of salmon reproducing naturally is very low. Most areas are re-stocked annually.[17] Since the extirpation of Atlantic salmon from Lake Ontario in the late 19th century, the state of New York has stocked its adjoining rivers and tributaries, and in many cases does not allow active fishing.[2][60][17]

The province of Ontario started the Atlantic Salmon Restoration Program[61] in 2006, which is one of the largest freshwater conservation programs in North America. It has since stocked Lake Ontario and surrounding tributaries with upwards of 6,000,000 young Atlantic salmon, with efforts growing each year.[62] In New England, many efforts are underway to restore salmon to the region by knocking down obsolete dams and updating others with fish ladders and other techniques that have proven effective in the West with Pacific salmon. There is some success thus far, with populations growing in the Penobscot and Connecticut Rivers. Lake Champlain now has Atlantic salmon. The Atlantic Salmon Federation is involved in restoration efforts along the eastern United States and Canada, where their projects are focused on removing barriers to fish passage and eradicating invasive species.[63]

Recent documented successes in the reintroduction of Atlantic salmon include the following:

  • In October 2007, salmon were video-recorded running in Toronto's Humber River by the Old Mill.[53]
  • A migrating salmon was observed in Ontario's Credit River in November 2007.[53]
  • As of 2013, there has been some success in establishing Atlantic salmon in Fish Creek, a tributary of Oneida Lake in central New York.[64]
  • In November 2015, salmon nests were observed in Connecticut in the Farmington River, a tributary of the Connecticut River where Atlantic salmon had not been observed spawning since "probably the Revolutionary War".[65] However, both state and federal experts indicated that this find likely represented a dwindling wave of returning stocked fish from massive salmon restoration efforts that had concluded years earlier in 2012. Significant doubt was cast on fish returning to spawn in meaningful numbers after 2017, when the last generation of stocked salmon would return.[66]

NASCO

The North Atlantic Salmon Conservation Organization is an international council made up of Canada, the European Union, Iceland, Norway, the Russian Federation, and the United States, with its headquarters in Edinburgh. It was established in 1983 to help protect Atlantic salmon stocks, through the cooperation between nations. They work to restore habitat and promote conservation of the salmon.[67] In December 2021, NASCO published an updated interactive map of their Rivers Database, showing the stock status of wild Atlantic salmon populations across the species range.

Legislation

England and Wales

Edward I instituted a penalty for collecting salmon during certain times of the year. His son Edward II continued, regulating the construction of weirs. Enforcement was overseen by those appointed by the justices of the peace. Because of confusing laws and the appointed conservators having little power, most laws were barely enforced.

Based on this, a royal commission was appointed in 1860 to thoroughly investigate the Atlantic salmon and the laws governing the species, resulting in the 1861 Salmon Fisheries Act. The act placed enforcement of the laws under the Home Office's control, but it was later transferred to the Board of Trade, and then later to the Board of Agriculture and Fisheries. Another act passed in 1865 imposed charges to fish and catch limits. It also caused the formation of local boards having jurisdiction over a certain river. The next significant act, passed in 1907, allowed the board to charge 'duties' to catch other freshwater fish, including trout.

Despite legislation, board effects decreased until, in 1948, the River Boards Act gave authority of all freshwater fish and the prevention of pollution to one board per river. In total, it created 32 boards. In 1974, the 32 boards, which by then were integrated into regional river authorities, were reduced to 10 regional water authorities (RWAs). Although only the Northumbrian Water Authority, Welsh National Water Development Authority, Northwest Water Authority and Southwest Water Authority had significant salmon populations, all ten also regulated and conserved trout and freshwater eel fisheries

The Salmon and Freshwater Fisheries Act was passed in 1975. Among other things, it regulated fishing licences, seasons, and size limits, and banned obstructing the salmon's migratory paths.[18]

Scotland

Salmon was greatly valued in medieval Scotland, and various fishing methods, including the use of weirs, cruives, and nets, were used to catch the fish. Fishing for salmon was heavily regulated in order to conserve the resource.[68] In 1318, King Robert I enacted legislation setting a minimum size for cruives, "so that no fry of fish are impeded from ascending and descending..." Laws on catching fish upon royal lands were frequently updated, demonstrating their importance.[68] Because the fish were held in such high regard, poachers were severely punished; a person twice convicted of poaching salmon on a royal estate could be sentenced to death.[69] The export of salmon was economically important in Aberdeen; beginning in the 15th century, the fish could be preserved through salting and barreling, allowing them to be exported abroad, including as far away as the Baltic. The volume of the early Scottish salmon trade is impossible to determine, since surviving custom records date only from the 1420 onward, and since Aberdeen burgesses enjoyed an exemption on salmon customs until the 1530s.[70]

During the 15th century, many laws were passed; many regulated fishing times, and worked to ensure smolts could safely pass downstream. James III even closed a meal mill because of its history of killing fish attracted to the wheel.

More recent legislation has established commissioners who manage districts. Furthermore, the Salmon and Freshwater Fisheries Act in 1951 required the Secretary of State be given data about the catches of salmon and trout to help establish catch limits.[18][36]

United States

Commercial and recreational fishing of wild, anadromous Atlantic salmon is prohibited in the United States.[5] Several populations of Atlantic salmon are in serious decline, and are listed as endangered under the Endangered Species Act (ESA). Currently, runs of 11 rivers in Maine are on the list – Kennebec, Androscoggin, Penobscot, Sheepscot, Ducktrap, Cove Brook, Pleasant, Narraguagus, Machias, East Machias and Dennys. The Penobscot River is the "anchor river" for Atlantic salmon populations in the US. Returning fish in 2008 were around 2,000, more than double the 2007 return of 940.

Section 9 of the ESA makes it illegal to take an endangered species of fish or wildlife. The definition of "take" is to "harass, harm, pursue, hunt, shoot, wound, kill, trap, capture, or collect, or to attempt to engage in any such conduct".[71]

Canada

The federal government has prime responsibility for protecting the Atlantic salmon, but over the last generation, effort has continued to shift management as much as possible to provincial authorities through memoranda of understanding, for example. A new Atlantic salmon policy is in the works, and in the past three years, the government has attempted to pass a new version of the century-old Fisheries Act through Parliament.

Federal legislation regarding at-risk populations is weak. Inner Bay of Fundy Atlantic salmon runs were declared endangered in 2000. A recovery and action plan is in place.[72]

Nongovernmental organizations, such as the Atlantic Salmon Federation,[73] constantly demand for improvements in management, and for initiatives to be considered. For example, the ASF and the Nova Scotia Salmon Association desire the use of technology for mitigation of acid rain-affected rivers such as used in Norway is in 54 Nova Scotia rivers and managed to raise the funds to get a project in place in one river.

In Quebec, the daily catch limit for Atlantic salmon is dependent on the individual river. Some rivers are strictly catch and release with a limit of 3 released fish. Each catch must be declared. Some rivers allow you to keep between 1 or 2 grilse (30 cm to 63 cm), while some of the more prolific rivers (mainly on the north coast) will allow you to keep 1 salmon over 63 cm. The annual catch limit is 4 Atlantic salmon of small size and only 1 of those may be bigger than 63 cm.

In Lake Ontario, the historic populations of Atlantic salmon became extinct, and cross-national efforts have been under way to reintroduce the species, with some areas already having restocked naturally reproducing populations.[74][75]

See also

Notes

  1. ^ World Conservation Monitoring Centre (1996). "Salmo salar". IUCN Red List of Threatened Species. 1996: e.T19855A9026693. doi:10.2305/IUCN.UK.1996.RLTS.T19855A9026693.en. Retrieved 29 May 2023.
  2. ^ a b c d e f The Audubon Society Field Guide to North American Fishes, Whales & Dolphins. Chanticleer Press. 1983. p. 395. ISBN 0394534050.
  3. ^ Barton, M.: "Biology of Fishes.", pages 198–202 Thompson Brooks/Cole 2007
  4. ^ a b c "Atlantic Salmon". animallist.weebly.com. Retrieved 19 November 2013.
  5. ^ a b "Atlantic salmon (Salmo salar)". NOAA Fisheries - Office of Protected Resources. 5 May 2017.
  6. ^ Buller F., The Domesday Book of Giant Salmon Volume 1 & 2. Constable (2007) & Constable (2010)
  7. ^ "Atlantic Salmon Life Cycle". Connecticut River Coordinator's Office. U.S. Fish and Wildlife Service. 13 September 2010. Archived from the original on 15 January 2014.
  8. ^ J. L. Horreo; G. Machado-Schiaffino; A. M. Griffiths; D. Bright; J. R. Stevens; E. Garcia-Vazquez (2011). "Atlantic Salmon at Risk: Apparent Rapid Declines in Effective Population Size in Southern European Populations". Transactions of the American Fisheries Society. 140 (3): 605–610. doi:10.1080/00028487.2011.585574.
  9. ^ Fay, C.; M. Bartron; S. Craig; A. Hecht; J. Pruden; R. Saunders; T. Sheehan; J. Trial (2006). Status Review for Anadromous Atlantic Salmon (Salmo salar) in the United States. Report to the National Marine Fisheries Service and U.S. Fish and Wildlife Service (Report). p. 294. Retrieved 3 July 2016.
  10. ^ Kendall, W. C. (1935). The fishes of New England: the salmon family. Part 2 - the salmons. Boston, Massachusetts: Memoirs of the Boston Society of Natural History: monographs on the natural history of New England. pp. 90. Retrieved 3 July 2016.
  11. ^ W.C. Kendall (1935). "The fishes of New England- the salmon family. Part 2 - the salmons". Memoirs of the Boston Society of Natural History- Monographs on the Natural History of New England. 9 (1): 1–166. Retrieved 3 July 2016.
  12. ^ Robert A. Daniels; Doroty Peteet (November 1998). "Fish scale evidence for rapid post-glacial colonization of an Atlantic coastal pond". Global Ecology and Biogeography Letters. 7 (6): 467–476. doi:10.2307/2997716. hdl:2060/19990023267. JSTOR 2997716. Retrieved 3 July 2016.
  13. ^ Catherine C. Carlson (1988). GP Nicholas (ed.). Where's the salmon? A reevaluation of the role of anadromous fisheries in aboriginal New England in Holocene human ecology in Northeastern North America. New York: Plenum Press. ISBN 978-0306428692.
  14. ^ Catherine C. Carlson (1996). "The [In]Significance of Atlantic Salmon". History Through a Pinhole. 8(3/4 (Fall/Winter). Retrieved 3 July 2016.
  15. ^ Stephen F. Jane; Keith H. Nislow; Andrew R. Whiteley (September 2014). "The use (and misuse) of archaeological salmon data to infer historical abundance in North America with a focus on New England". Reviews in Fish Biology and Fisheries. 24 (3): 943–954. doi:10.1007/s11160-013-9337-3. S2CID 15892424.
  16. ^ Brian S. Robinson; George L. Jacobson; Martin G. Yates; Arthur E. Spiess; Ellen R. Cowie (October 2009). "Atlantic salmon, archaeology and climate change in New England". Journal of Archaeological Science. 36 (10): 2184–2191. doi:10.1016/j.jas.2009.06.001.
  17. ^ a b c d Dymond, John R.; MacKay, Hugh H.; Burridge, Mary E.; Holm, Erling; Bird, Phillip W. (2019). "The history of the Atlantic Salmon in Lake Ontario". Aquatic Ecosystem Health & Management. 22 (3): 305–315. doi:10.1080/14634988.2019.1641044. ISSN 1463-4988. S2CID 202851801.
  18. ^ a b c d e f g Shearer, W. (1992). The Atlantic Salmon. Halstead Press.
  19. ^ a b c Renzi, Vanessa. "ADW: Salmo salar: INFORMATION". Animaldiversity.org. Retrieved 23 August 2022.
  20. ^ Fisheries, NOAA (21 August 2018). "Atlantic Salmon - Protected | NOAA Fisheries". www.fisheries.noaa.gov. Retrieved 26 November 2018.
  21. ^ a b "Study sheds light on extinct Lake Ontario salmon". Toronto Star, 9 November 2016, page GT1.
  22. ^ a b c Klemetsen A, Amundsen P-A, Dempson JB, Jonsson B, Jonsson N, O'Connell MF, Mortensen E (2003). "Atlantic salmon Salmo salar L., brown trout Salmo trutta L. and Arctic charr Salvelinus alpinus (L.): a review of aspects of their life histories". Ecology of Freshwater Fish. 12: 1–59. doi:10.1034/j.1600-0633.2003.00010.x.
  23. ^ a b c d Heen, K. (1993). Salmon Aquaculture. Halstead Press.
  24. ^ Youngson, A. F., Webb, J. H., Thompson, C. E., and Knox, D. 1993. Spawning of escaped farmed Atlantic salmon (Salmo salar): hybridization of females with brown trout (Salmo trutta). Canadian Journal of Fisheries and Aquatic Sciences, 50:1986-1990.
  25. ^ Matthews, M. A., Poole, W. R., Thompson, C. E., McKillen, J., Ferguson, A., Hindar, K., and Wheelan, K. F. 2000. Incidence of hybridization between Atlantic salmon, Salmo salar L., and brown trout, Salmo trutta L., in Ireland. Fisheries Management and Ecology, 7:337–347.
  26. ^ Seawater tolerance in Atlantic salmon, Salmo salar L., brown trout, Salmo trutta L., and S. salar × S. trutta hybrids smolt. Urke HA, Koksvik J, Arnekleiv JV, Hindar K, Kroglund F, Kristensen T. Source Norwegian Institute of Water Research, 7462, Trondheim, Norway
  27. ^ Leaniz, C. Garcia; Verspoor, E. (1989). "Natural hybridization between Atlantic salmon, Salmo salar, and brown trout, Salmo trutta, in northern Spain". Journal of Fish Biology. 34 (1): 41–46. doi:10.1111/j.1095-8649.1989.tb02956.x – via www.academia.edu.
  28. ^ a b c P. Collen & R. J. Gibson (2001). "The general ecology of beavers (Castor spp.), as related to their influence on stream ecosystems and riparian habitats, and the subsequent effects on fish – a review". Reviews in Fish Biology and Fisheries. 10 (4): 439–461. doi:10.1023/A:1012262217012. S2CID 8713798.
  29. ^ Howard Park & Øystein Cock Rønning (2007). "Low potential for restraint of anadromous salmonid reproduction by beaver Castor fiber in the Numedalslågen river catchment, Norway". River Research and Applications. 23 (7): 752–762. doi:10.1002/rra.1008. S2CID 128889683.
  30. ^ Barry A. Taylor; Charles MacInnis; Trevor A. Floyd (2010). "Influence of Rainfall and Beaver Dams on Upstream Movement of Spawning Atlantic Salmon in a Restored Brook in Nova Scotia, Canada". River Research and Applications: 183–193. doi:10.1002/rra.1252. S2CID 128484339.
  31. ^ Douglas B. Sigourney, Benjamin H. Letcher & Richard A. Cunjak (2006). "Influence of beaver activity on summer growth and condition of age-2 Atlantic salmon parr". Transactions of the American Fisheries Society. 135 (4): 1068–1075. doi:10.1577/T05-159.1. S2CID 84441693.
  32. ^ "The River". The Penobscot River Restoration Trust. 25 September 2013. Retrieved 19 November 2013.
  33. ^ Jenkins, J. Geraint (1974). Nets and Coracles, p. 68. London, David and Charles.
  34. ^ Netboy, Anthony (1973) The Salmon: Their Fight for Survival, pp. 181–182. Boston, Houghton Mifflin.
  35. ^ Bittman, Mark (10 April 2009). "The Bottom Line on Salmon". Diner’s Journal Blog. New York Times. Retrieved 8 May 2021.
  36. ^ a b Sedgwick, S. (1988). Salmon Farming Handbook. Fishing News Books LTD.
  37. ^ N. Bromage (1995). Broodstock Management and Egg and Larval Quality. Blackwell Science.
  38. ^ a b Food and Agriculture Organization of the United Nations. (2015). Aquaculture operations in floating HDPE cages - A field handbook. Retrieved from http://www.fao.org/3/i4508e/i4508e.pdf
  39. ^ Thorstad, Eva B.; Fleming, Ian A.; McGinnity, Philip; Soto, Doris; Wennevik, Vidar; Whoriskey, Fred (2008). Incidence and impacts of escaped farmed Atlantic salmon Salmo salar in nature (PDF). World Wildlife Fund, Inc. p. 6. ISBN 978-82-426-1966-2. Retrieved 25 August 2017.
  40. ^ Wringe, Brenden; et al. (2018). "Extensive hybridization following a large escape of domesticated Atlantic salmon in the Northwest Atlantic". Communications Biology. 1: 108. doi:10.1038/s42003-018-0112-9. PMC 6123692. PMID 30271988.
  41. ^ Ford, Jennifer S.; Myers, Ransom A. (12 February 2008). "A Global Assessment of Salmon Aquaculture Impacts on Wild Salmonids". PLOS Biology. 6 (2): e33. doi:10.1371/journal.pbio.0060033. ISSN 1545-7885. PMC 2235905. PMID 18271629.
  42. ^ Barry, Tricia K.; VanderZwaag, David L. (2007). Preventing Salmon Escapes from Aquaculture in Canada and the USA: Limited International Coordinates, Divergent Regulatory Currents and Possible Future Courses (PDF). Oxford, UK: Blackwell Publishing Ltd. p. 58. Retrieved 25 August 2017.
  43. ^ Donaldson, Jim (22 August 2017). "Fish farm fiasco: Why officials want you to catch as many salmon as you can". Bellingham Herald. Retrieved 23 August 2017.
  44. ^ Treviño, Julissa. "Why Washington State Is Phasing Out Atlantic Salmon Farming". Smithsonian Magazine. Retrieved 16 July 2020.
  45. ^ Mapes, Linda V.; Bernton, Hal (22 August 2017). "Please go fishing, Washington state says after farmed Atlantic salmon escape broken net". The Seattle Times. Retrieved 27 December 2017.
  46. ^ Amos, Kevin H.; Appleby, Andrew. "Atlantic Salmon in Washington State: A Fish Management Perspective" (PDF). Washington Department of Fish & Wildlife. State of Washington. Archived from the original (PDF) on 28 August 2017. Retrieved 27 December 2017.
  47. ^ Pechlaner, Gabriela; Rutherford, Murray B. (Summer 2006). "Common Future, Different Policy Paths? Managing the Escape of Farmed Atlantic Salmon in British Columbia and Washington State". BC Studies. No 150: Aquaculture (150): 47. doi:10.14288/bcs.v0i150.692. Retrieved 25 August 2017.
  48. ^ R. M. J. Ginetz (May 2002). "On the Risk of Colonization by Atlantic Salmon in BC waters". B.C. Salmon Farmers Association.
  49. ^ Næve, Ingun; Korsvoll, Sven A.; Santi, Nina; Medina, Matias; Aunsmo, Arnfinn (2022). "The power of genetics: Past and future contribution of balanced genetic selection to sustainable growth and productivity of the Norwegian Atlantic salmon (Salmo salar) industry". Aquaculture. 553: 738061. doi:10.1016/j.aquaculture.2022.738061. S2CID 247071145.
  50. ^ a b Centre, World Conservation Monitoring (1 August 1996). "IUCN Red List of Threatened Species: Salmo salar". IUCN Red List of Threatened Species. Retrieved 12 July 2021.
  51. ^ World Conservation Monitoring Centre (1996). "Salmo salar". IUCN Red List of Threatened Species. 1996: e.T19855A9026693. doi:10.2305/IUCN.UK.1996.RLTS.T19855A9026693.en. Retrieved 19 November 2021.
  52. ^ Fisheries, NOAA (22 June 2021). "Atlantic Salmon (Protected) | NOAA Fisheries". NOAA. Retrieved 12 July 2021.
  53. ^ a b c Harb, M. "Upstream Battle", Canadian Geographic Magazine, June 2008, p. 24
  54. ^ a b "Salmon campaigner lands top award". BBC News. 22 April 2007.
  55. ^ B. Dempson; C. J. Schwarz; D. G. Reddin; M. F. O'Connell; C. C. Mullins; C. E. Bourgeois (2001). "Estimation of marine exploitation rates on Atlantic salmon (Salmo salar L.) stocks in Newfoundland, Canada". ICES Journal of Marine Science. 58: 331–341. doi:10.1006/jmsc.2000.1014.
  56. ^ Carpenter, Murray (26 December 2011). "Shiny Patches in Maine's Streambeds Are Bright Sign for Salmon". The New York Times. Retrieved 11 February 2012.
  57. ^ a b RichardAntoine; BernatchezLouis; ValiquetteEliane; DionneMélanie (16 July 2014). "Telemetry reveals how catch and release affects prespawning migration in Atlantic salmon (Salmo salar)". Canadian Journal of Fisheries and Aquatic Sciences. 71 (11): 1730–1739. doi:10.1139/cjfas-2014-0072.
  58. ^ Government of Canada, Fisheries and Oceans Canada (14 April 2021). "Atlantic Salmon Recreational Fishing for the Gulf Region in 2021". www.glf.dfo-mpo.gc.ca. Retrieved 28 July 2021.
  59. ^ Leeuwen, Travis E. Van; Dempson, J. Brian; Burke, Chantelle M.; Kelly, Nicholas I.; Robertson, Martha J.; Lennox, Robert J.; Havn, Torgeir B.; Svenning, Martin; Hinks, Ross; Guzzo, Matthew M.; Thorstad, Eva B. (8 June 2020). "Mortality of Atlantic salmon after catch and release angling: assessment of a recreational Atlantic salmon fishery in a changing climate". Canadian Journal of Fisheries and Aquatic Sciences. 77 (9): 1518–1528. doi:10.1139/cjfas-2019-0400. hdl:11250/2671784. S2CID 225771922.
  60. ^ Mills, D. (1989). Ecology and Management of Atlantic Salmon. Springer-Verlag.
  61. ^ "Lake Ontario Atlantic Salmon Restoration Program |".
  62. ^ "About the Program | Lake Ontario Atlantic Salmon Restoration Program". Retrieved 12 August 2021.
  63. ^ "Restoration". Atlantic Salmon Federation. Retrieved 12 August 2021.
  64. ^ Figura, David (13 August 2013). "Cicero angler lands 27-inch Atlantic salmon in Oneida Lake". Syracuse.com. Syracuse Media Group. Retrieved 4 February 2016.
  65. ^ Hladky, Gregory B. (25 December 2015). "Salmon Found Spawning in Farmington River Watershed For First Time in Centuries". Hartford Courant. Tribune Company. Retrieved 4 February 2016.
  66. ^ Vancini, Peter (29 March 2016). "So Long, Salmon! Atlantic salmon are spawning in the CT River, but it's too little, too late". Valley Advocate. Retrieved 26 October 2021.
  67. ^ "NASCO ~ The North Atlantic Salmon Conservation Organization". Nasco.int. Archived from the original on 21 January 2013. Retrieved 11 February 2012.
  68. ^ a b Kate Buchanan, "Wheeles and Creels: The Physical Representation of the Right to Milling and Fishing in Sixteenth-Century Angus, Scotland" in Medieval and Early Modern Representations of Authority in Scotland and the British Isles (eds. Kate Buchanan & Lucinda H.S. Dean with Michael Penman: Routledge, 2016), pp. 59–60.
  69. ^ Jim Mac Laughlin,Troubled Waters: A Social and Cultural History of Ireland's Sea Fisheries (Four Courts Press, 2010), p. 77.
  70. ^ Katie Stevenson, Power and Propaganda: Scotland, 1306–1488 (Edinburgh University Press, 2014).
  71. ^ (16 U.S.C. 1532(19)) [1]
  72. ^ Canada, Environment and Climate Change (10 September 2019). "Atlantic Salmon inner Bay of Fundy population: action plan". www.canada.ca.
  73. ^ "Atlantic Salmon Federation". Atlantic Salmon Federation.
  74. ^ "Frequently Asked Questions (FAQ)". Bring Back the Salmon Lake Ontario. Archived from the original on 11 August 2015. Retrieved 17 September 2015.
  75. ^ "Endangered Populations". Atlantic Salmon Federation. Archived from the original on 19 September 2015. Retrieved 17 September 2015.

References

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Atlantic salmon: Brief Summary

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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 found in the northern Atlantic Ocean and in rivers that flow into it. Most populations are anadromous, hatching in streams and rivers but moving out to sea as they grow where they mature, after which the adults seasonally move upstream again to spawn.

When the mature fish re-enter rivers to spawn, they change in colour and appearance. Some populations of this fish only migrate to large lakes, and are "landlocked", spending their entire lives in freshwater. Such populations are found throughout the range of the species. Unlike Pacific species of salmon, S. salar is iteroparous, which means it can survive spawning and return to sea to repeat the process again in another year with 5-10% returning to the sea to spawn again. Such individuals can grow to extremely large sizes, although they are rare. The different life stages of the fish are known by many different names in English: alevin, fry, parr and smolt.

Atlantic salmon is considered a very healthy food and one of the fish with a more refined taste in many cultures. As such it features in numerous popular traditional cuisines and can fetch a higher price than some other fish. It has thus long been the target of recreational and commercial fishing, and this, as well as habitat destruction, has impacted the population in some areas. As a result, the species is the subject of conservation efforts in several countries, which appear to have been somewhat successful since the 2000s. Techniques to farm this species using aquacultural methods have also been developed, and at present it is farmed in great numbers in many places around the world. Although this is now a viable alternative to wild-caught fish, farming methods have attracted criticism from environmentalists.

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Diet

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Feeds on mollusks, crustaceans, insects, squids, shrimps, herring, alewives and smelts

Reference

North-West Atlantic Ocean species (NWARMS)

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Distribution

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northern Quebec to Connecticut

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North-West Atlantic Ocean species (NWARMS)

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Habitat

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anadromous species; born in large, cool rivers, migrate to sea after 1-6 years, then return to natal rivers to spawn

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North-West Atlantic Ocean species (NWARMS)

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Habitat

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nektonic

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North-West Atlantic Ocean species (NWARMS)

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Introduction

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This species has been introduced or released in Dutch waters.

Reference

2. Fish, J. D. & Fish, S. (1996) A student's guide to the seashore. Second Edition. Cambridge University Press, Cambridge.

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