Salmon in the context of Steelhead trout

Fishery can mean either the enterprise of raising or harvesting fish and other aquatic life or, more commonly, the site where such enterprise takes place (a.k.a., fishing grounds). Commercial fisheries include wild fisheries and fish farms, both in freshwater waterbodies (about 10% of all catch) and the oceans (about 90%). About 500 million people worldwide are economically dependent on fisheries. 171 million tonnes of fish were produced in 2016, but overfishing is an increasing problem, causing declines in some populations.

Because of their economic and social importance, fisheries are governed by complex fisheries management practices and legal regimes that vary widely across countries. Historically, fisheries were treated with a "first-come, first-served" approach, but recent threats from human overfishing and environmental issues have required increased regulation of fisheries to prevent conflict and increase profitable economic activity on the fishery. Modern jurisdiction over fisheries is often established by a mix of international treaties and local laws.

Becharof National Wildlife Refuge is a National Wildlife Refuge in the Aleutian Range of the Alaska Peninsula of southwestern Alaska. It is adjacent to Katmai National Park and Preserve. This national wildlife refuge, which covers an area of 1,200,000 acres (4,900 km), was established in 1980 to conserve major brown bears, salmon, migratory birds, caribou, marine birds, and mammals and to comply with treaty obligations. It lies primarily in the east-central part of Lake and Peninsula Borough, but extends eastward into the mainland portion of Kodiak Island Borough. The refuge is administered from offices in King Salmon.

Becharof Wilderness it comprises approximately 500,000 acres (2,000 km) and is bordered by the Katmai Wilderness on the north. It was designated a wilderness area in 1980 by the Alaska National Interest Lands Conservation Act.

Fish farming or pisciculture involves commercial breeding of fish, most often for food, in fish tanks or artificial enclosures such as fish ponds. It is a particular type of aquaculture, which is the controlled cultivation and harvesting of aquatic animals such as fish, crustaceans, molluscs and so on, in natural or pseudo-natural environments. A facility that releases juvenile fish into the wild for recreational fishing or to supplement a species' natural numbers is generally referred to as a fish hatchery. Worldwide, the most important fish species produced in fish farming are carp, catfish, salmon and tilapia.

Global demand is increasing for dietary fish protein, which has resulted in widespread overfishing in wild fisheries, resulting in significant decrease in fish stocks and even complete depletion in some regions. Fish farming allows establishment of artificial fish colonies that are provided with sufficient feeding, protection from natural predators and competitive threats, access to veterinarian service, and easier harvesting when needed, while being separate from and thus do not usually impact the sustainable yields of wild fish populations. While fish farming is practised worldwide, China alone provides 62% of the world's farmed fish production. As of 2016, more than 50% of seafood was produced by aquaculture. In the last three decades, aquaculture has been the main driver of the increase in fisheries and aquaculture production, with an average growth of 5.3 percent per year between 2000 and 2018, rising from 32.4 to 82.1 million tonnes.

Fish marketing is the marketing and sale of fish products.

Carotenoids (/kəˈrɒtɪnɔɪd/) are yellow, orange, and red organic pigments that are produced by plants and algae, as well as several bacteria, archaea, and fungi. Carotenoids give the characteristic color to pumpkins, carrots, parsnips, corn, tomatoes, canaries, flamingos, salmon, lobster, shrimp, and daffodils. Over 1,100 identified carotenoids can be further categorized into two classes – xanthophylls (which contain oxygen) and carotenes (which are purely hydrocarbons and contain no oxygen).

All are derivatives of tetraterpenes, meaning that they are produced from 8 isoprene units and contain 40 carbon atoms. In general, carotenoids absorb wavelengths ranging from 400 to 550 nanometers (violet to green light). This causes the compounds to be deeply colored yellow, orange, or red. Carotenoids are the dominant pigment in autumn leaf coloration of about 15-30% of tree species, but many plant colors, especially reds and purples, are due to polyphenols.

Biomass is the total mass of living biological organisms in a given area or ecosystem at a specific time. Biomass may refer to the species biomass, which is the mass of one or more species, or to community biomass, which is the mass of all species in the community. It encompasses microorganisms, plants, and animals, and is typically expressed as total mass or average mass per unit area.

The method used to measure biomass depends on the context. In some cases, biomass refers to the wet weight of organisms as they exist in nature. For example, in a salmon fishery, the salmon biomass might be regarded as the total wet weight the salmon would have if they were taken out of the water. In other contexts, biomass can be measured in terms of the dried organic mass, so perhaps only 30% of the actual weight might count, the rest being water. In other contexts, it may refer to dry weight (excluding water content), or to the mass of organic carbon, excluding inorganic components such as bones, shells, or teeth.

A rebus (/ˈriːbəs/ REE-bəss) is a puzzle device that combines the use of illustrated pictures with individual letters to depict words or phrases. For example: the word "been" might be depicted by a rebus showing an illustrated bumblebee next to a plus sign (+) and the letter "n".

It was a favourite form of heraldic expression used in the Middle Ages to denote surnames. For example, in its basic form, three salmon (fish) are used to denote the surname "Salmon". A more sophisticated example was the rebus of Bishop Walter Lyhart (d. 1472) of Norwich, consisting of a stag (or hart) lying down in a conventional representation of water. The composition alludes to the name, profession or personal characteristics of the bearer, and speaks to the beholder Non verbis, sed rebus, which Latin expression signifies "not by words but by things" (res, rei (f), a thing, object, matter; rebus being ablative plural).

Fish migration is mass relocation by fish from one area or body of water to another. Many types of fish migrate on a regular basis, on time scales ranging from daily to annually or longer, and over distances ranging from a few metres to thousands of kilometres. Such migrations are usually done for better feeding or to reproduce, but in other cases the reasons are unclear.

Fish migrations involve movements of schools of fish on a scale and duration larger than those arising during normal daily activities. Some particular types of migration are anadromous, in which adult fish live in the sea and migrate into fresh water to spawn; and catadromous, in which adult fish live in fresh water and migrate into salt water to spawn.

The Nivkh, or Gilyak (also Nivkhs or Nivkhi, or Gilyaks; ethnonym: Нивхгу, Nʼivxgu (Amur) or Ниғвңгун, Nʼiɣvŋgun (E. Sakhalin) "the people"), are an indigenous ethnic group inhabiting the northern half of Sakhalin Island and the lower Amur River and coast on the adjacent Russian mainland. Historically, they may have inhabited parts of Manchuria.

Nivkh were traditionally fishermen, hunters, and dog breeders. They were semi-nomadic, living near the coasts in the summer and wintering inland along streams and rivers to catch salmon. The land the Nivkh inhabit is characterized as taiga forest with cold snow-laden winters and mild summers with sparse tree cover. The Nivkh are believed to be the original inhabitants of the region, and to derive from a proposed Neolithic people that migrated from the Transbaikal region during the Late Pleistocene.

The Indigenous peoples of the Pacific Northwest Coast are composed of many nations and tribal affiliations, each with distinctive cultural and political identities. They share certain beliefs, traditions and practices, such as the centrality of salmon as a resource and spiritual symbol, and many cultivation and subsistence practices. The term Northwest Coast or North West Coast is used in anthropology to refer to the groups of Indigenous people residing along the coast of what is now called British Columbia, Washington State, parts of Alaska, Oregon, and Northern California. The term Pacific Northwest is largely used in the American context.

At one point, the region had the highest population density of a region inhabited by Indigenous peoples in Canada.

The Pacific decadal oscillation (PDO) is a robust, recurring pattern of ocean-atmosphere climate variability centered over the mid-latitude Pacific basin. The PDO is detected as warm or cool surface waters in the Pacific Ocean, north of 20°N. Over the past century, the amplitude of this climate pattern has varied irregularly at interannual-to-interdecadal time scales (meaning time periods of a few years to as much as time periods of multiple decades). There is evidence of reversals in the prevailing polarity (meaning changes in cool surface waters versus warm surface waters within the region) of the oscillation occurring around 1925, 1947, and 1977; the last two reversals corresponded with dramatic shifts in salmon production regimes in the North Pacific Ocean. This climate pattern also affects coastal sea and continental surface air temperatures from Alaska to California.

During a "warm", or "positive", phase, the west Pacific becomes cooler and part of the eastern ocean warms; during a "cool", or "negative", phase, the opposite pattern occurs. The Pacific decadal oscillation was named by Steven R. Hare, who noticed it while studying salmon production pattern results in 1997.

The Žeimena River is a river in Aukštaitija, eastern Lithuania, and right tributary of Neris River. Žeimena begins in Labanoras Forest and at Lake Žeimenys. Žeimena flows to the south passing Kaltanėnai town, Švenčionėliai city, and Pabradė city. Its confluence with Neris is located near the border of Švenčionys and Vilnius districts. The main tributaries of Žeimena are Lakaja, Saria, Mera [lt], Kiauna, Luknelė and Jusinė.

Žeimena is one of the cleanest rivers in Lithuania. Also, it is one of the main places of salmon's spawning. The length of Žeimena is an object of discussion because it originates in a large lakeland of Aukštaitija National Park. The lakeland has many lakes that are interconnected by various rivers and streams, so it is difficult to say which lake is the source of which river. Traditionally, Lake Žeimenys is considered to be the source of Žeimena.

The River Suir (/ʃʊər/ SHOOR; Irish: an tSiúr [ənʲ ˈtʲuːɾˠ] or Abhainn na Siúire [ˌəun̠ʲ n̪ˠə ˈʃuːɾʲə]) is a river in Ireland that flows into the Celtic Sea through Waterford after a distance of 185 kilometres (115 mi).The catchment area of the Suir is 3,610 km.Its long-term average flow rate is 76.9 cubic metres per second (m/s), about twice the flow of either the River Barrow (37.4 m/s) or the River Nore (42.9 m/s) before these join, but a little less than the Barrow's flow when it meets the Suir 20 km downstream (over 80 m/s).

Popular with anglers, it abounds in brown trout and salmon. Although the Suir holds the record for a salmon taken from an Irish river (weighing 57 lb/26 kg, taken on a fly in 1874), as has been the case in many other Atlantic rivers, salmon stocks have been in decline in recent years.

Euryhaline organisms are able to adapt to a wide range of salinities. An example of a euryhaline fish is the short-finned molly, Poecilia sphenops, which can live in fresh water, brackish water, or salt water.

The green crab (Carcinus maenas) is an example of a euryhaline invertebrate that can live in salt and brackish water. Euryhaline organisms are commonly found in habitats such as estuaries and tide pools where the salinity changes regularly. However, some organisms are euryhaline because their life cycle involves migration between freshwater and marine environments, as is the case with salmon and eels.

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).