Atlantic salmon in the context of "Salmonids"

Animal migration is the relatively long-distance movement of individual animals, usually on a seasonal basis. It is the most common form of migration in ecology. It is found in all major animal groups, including birds, mammals, fish, reptiles, amphibians, insects, and crustaceans. The cause of migration may be local climate, local availability of food, the season of the year or for mating.

To be counted as a true migration, and not just a local dispersal or irruption, the movement of the animals should be an annual or seasonal occurrence, or a major habitat change as part of their life. An annual event could include Northern Hemisphere birds migrating south for the winter, or wildebeest migrating annually for seasonal grazing. A major habitat change could include young Atlantic salmon or sea lamprey leaving the river of their birth when they have reached a few inches in size. Some traditional forms of human migration fit this pattern.

The River Lagan (from Irish Abhainn an Lagáin 'river of the low-lying district'; Ulster Scots: Lagan Wattèr) is a major river in Northern Ireland which runs 53.5 mi (86.1 km) from the Slieve Croob mountain in County Down to Belfast where it enters Belfast Lough, an inlet of the Irish Sea. The Lagan forms much of the border between County Antrim and County Down in the east of Ulster. It rises as a stream near to the summit of Slieve Croob. It runs to Belfast through Dromara, Donaghcloney and Dromore. On the lower slopes of the mountain, it combines with a branch from Legananny Mountain, just opposite Slieve Croob. The river then turns east to Magheralin into a broad plain between the plateaus of Antrim and Down.

The river drains approximately 609 square km of agricultural land and flows to the Stranmillis Weir, from which point on it is estuarine. The catchment consists mainly of enriched agricultural grassland in the upper parts, with the lower section draining urban Belfast and Lisburn. There is one significant tributary, the Ravernet River, and there are several minor tributaries, including the Carryduff River, the River Farset and the Blackstaff River. Work is proceeding to restore a self-sustaining population of Atlantic salmon to the river.

The Blackwater or Munster Blackwater (Irish: An Abhainn Mhór, The Great River) is a river which flows through counties Kerry, Cork and Waterford in Ireland. It rises in the Mullaghareirk Mountains in County Kerry and then flows in an easterly direction across County Cork through the towns of Mallow and Fermoy. It then enters County Waterford where it flows through Lismore, before abruptly turning south at Cappoquin and finally draining into the Celtic Sea at Youghal Harbour in Cork. In total, the Blackwater is 169 km (105 mi) long.

The total catchment area of the River Blackwater is 3,324 km. Its long-term average flow rate of is 89.1 cubic metres per second (m/s) The Blackwater is notable for being one of the best salmon fishing rivers in the country. Like many Irish rivers, salmon stocks declined in recent years, but the Irish government banned commercial netting of salmon off the coast of Ireland in November 2006.

Salmo is a genus of ray-finned fish from the subfamily Salmoninae of family Salmonidae, and is part of the tribe Salmonini along with the sister genera Salvelinus and Salvethymus. Almost all Salmo species are native only in the Old World (including most of Europe, coastal North Africa and part of West Asia around the Black Sea), the only exception being the Atlantic salmon (Salmo salar), which is also naturally found across the North Atlantic in eastern North America.

The number of distinct species and subspecies in Salmo is a debated issue. The Atlantic salmon and brown trout (Salmo trutta) are widespread species and have been introduced worldwide as farmed food fish or recreational game fish, while most of the other Salmo species are narrowly distributed forms endemic to single watersheds.

Salmonidae (/sælˈmɒnɪdiː/, lit. 'salmon-like') is a family of ray-finned fish, the only extant member of the suborder Salmonoidei, consisting of 11 extant genera and over 200 species collectively known as "salmonids" or "salmonoids". The family includes salmon (both Atlantic and Pacific species), trout (both ocean-going and landlocked), char, graylings, freshwater whitefishes, taimens and lenoks, all coldwater mid-level predatory fish that inhabit the subarctic and cool temperate waters of the Northern Hemisphere. The Atlantic salmon (Salmo salar), whose Latin name became that of its genus Salmo, is also the eponym of the family and order names.

Salmonids have a relatively primitive appearance among teleost fish, with the pelvic fins being placed far back, and an adipose fin towards the rear of the back. They have slender bodies with rounded scales and forked tail fins, and their mouths contain a single row of sharp teeth. Although the smallest salmonid species is just 13 cm (5.1 in) long for adults, most salmonids are much larger, with the largest reaching 2 m (6 ft 7 in).

A salmon run is an annual fish migration event where many salmonid species, which are typically hatched in fresh water and live most of their adult life downstream in the ocean, swim back against the stream to the upper reaches of rivers to spawn on the gravel beds of small creeks. After spawning, most Atlantic salmon and all species of Pacific salmon die, and the salmon life cycle starts over again with the new generation of hatchlings.

Salmon are anadromous, spending their juvenile life in rivers or lakes, and then migrating out to sea where they spend adult lives and gain most of their body mass. When they reach sexual maturity, the adults return to the upstream rivers to reproduce. Usually they return with uncanny precision to the natal river where they were born, and even to the very spawning ground of their birth. It is thought that, when they are in the ocean, they use magnetoreception to locate the general position of their natal river, and once close to the river, that they use their sense of smell to home in on the river entrance and even their natal spawning ground.

AquAdvantage salmon is a genetically engineered (GE) fish, a GE Atlantic salmon developed by AquaBounty Technologies in 1989. The typical growth hormone-regulating gene in the Atlantic salmon was replaced with the growth hormone-regulating gene from Pacific Chinook salmon, with a promoter sequence from ocean pout. This gene enables GM salmon to grow year-round instead of only during spring and summer.

These GE salmon are a commercially competitive alternative to wild-caught salmon and to fish farming of unmodified salmon. The purpose of the modifications is to increase the speed at which the fish grows without affecting its ultimate size or other qualities. Fish-farmed Atlantic salmon growth rates have already been improved over wild fish as a result of traditional selective breeding practices. However, GM fish are able to grow even faster and grow to market size in just 16 to 18 months rather than three years.

Catch and release is a practice within recreational fishing where after capture the fish is unhooked and returned live to the water. Originally adopted in the United Kingdom by coarse fishermen to preserve fish populations, it has since become a widely used technique to permit people to fish recreationally while ensuring sustainability in the face of growing human populations, mounting ecological pressure, increasingly effective fishing tackle and techniques, inadequate fishing regulations and enforcement, and habitat degradation.

Between 18 and 20% of fish released die from injuries and stress, although the rate varies by species. Among those that survive, their injuries may significantly reduce their ability to feed and grow. During tournaments, inadequate holding and weighing procedures may further increase mortality. With deep sea fishing in particular, fish are typically unable to adjust their physiology to the sudden pressure change. Scientific and philosophical debates over whether fish feel pain in a way similar to humans are unresolved. In the 21st century, there is a greater emphasis on developing techniques which increase the likelihood that released fish will survive, such as using barbless hooks. Catch and release is banned in Switzerland and Germany, while Canada requires barbless hooks in some cases.

The aquaculture of salmonids is the farming and harvesting of salmonid fish under controlled conditions for both commercial and recreational purposes. Salmonids (particularly salmon and rainbow trout), along with carp and tilapia, are the three most important fish groups in aquaculture. The most commonly commercially farmed salmonid is the Atlantic salmon (Salmo salar).

In the United States, Chinook salmon and rainbow trout are the most commonly farmed salmonids for recreational and subsistence fishing through the National Fish Hatchery System. In Europe, brown trout are the most commonly reared fish for recreational restocking. Commonly farmed non-salmonid fish groups include tilapia, catfish, black sea bass and bream. In 2007, the aquaculture of salmonids was worth USD $10.7 billion globally. Salmonid aquaculture production grew over ten-fold during the 25 years from 1982 to 2007. In 2012, the leading producers of salmonids were Norway, Chile, Scotland and Canada.