The company's primary interest is fish farming, primarily salmon, the operations of which are focused on Norway, Scotland, Canada, the Faroe Islands, Ireland and Chile.

The company assumed its current form as a result of massive expansion in 2006, when Pan Fish ASA conducted an effective three-way merger with Marine Harvest N.V. and Fjord Seafood.

[10] In 1992, Unilever sold the business to Lord's Hanson and White, together with Ground Round restaurants, Tommy Armour golf clubs and a tuna processor in Long Island California.

[14] After deciding to divest Marine Harvest McConnell so as to concentrate on its core cash and carry business in 1998, Booker eventually succeeded in finding a buyer in July 1999.

[19] In May 2005, Nutreco merged its fish-farming operations with the salmon, trout, halibut, tilapia, cod, sturgeon and caviar businesses of Stolt-Nielsen,[20] creating a new stand-alone company, again named Marine Harvest.

[22] When the market price of salmon collapsed in 2001,[23] Pan Fish encountered extreme financial difficulties, posting a heavy loss in 2002,[24] and having to sell off assets in order to repay creditors.

[28] Fjord Seafood has its origins in Torgnes Invest, a company founded in June 1996 which initially operated a single fish farm in the Norwegian town of Brønnøysund.

[29] Expansion over the following four years was aggressive—by September 2000, when Fjord Seafood (as it was now called) listed on the Oslo Stock Exchange, the company's portfolio comprised 60 ongrowing concessions, of which 50 were wholly owned, as well as a number of smolt and broodstock farms, slaughterhouses and processing factories.

[30] Fjord continued to conduct mergers and acquisitions - the purchase of Belgian fish-processing company Pieters N.V. in November 2000[31] was swiftly followed by the addition of ContiSea, the seafood joint-venture of ContiGroup and Seaboard Corporation.

[37] Moves toward consolidation in the aquaculture sector were sparked by the activity of shipping magnate John Fredriksen, Norway's richest man before abandoning his citizenship of the country in 2006.

[40] In October of that year, with salmon prices high,[41] Fjord submitted an offer for a majority stake in Cermaq to the Norwegian Government, which was preparing it for a public listing.

[42] Fredriksen's efforts to effect change finally bore fruit in March 2006, as Geveran Trading succeeded in purchasing Marine Harvest from its joint owners for €881 million, before immediately turning ownership over to Pan Fish.

[49] After an initial deal to sell the unit to Norskott Havbruk, owners of rival company Scottish Sea Farms, was called off in July 2007,[50] Pan Fish Scotland was spun off into a separate publicly traded entity, Lighthouse Caledonia, that November.

[54] Eide was replaced on an interim basis by Leif Frode Onarheim, before the CEO position was filled permanently by former GE Healthcare executive Åse Aulie Michelet in March 2008.

In Scotland, Mowi operates 25 sea farms, plus three hatcheries (in Lochailort, Finfish and Inchmore), four freshwater loch sites, a harvest station in Mallaig and a processing plant in Fort William.

[83][84] The rapid propagation of the virus has motivated the enterprise to sell some of its facilities, firing more than a thousand employees,[83] with the aim of moving its installations further south to the Aisén Region.

[86] In January 2017 Private Eye reported that Mowi had been depositing large quantities of the insecticide azamethiphos into Scottish waters to control sea lice in salmon.

[87] In April 2019 Irish minister for marine Michael Creed discontinued a fish farm licence held by Mowi in County Kerry for overstocking.

[88] On February 18, 2020 Mowi Scotland assistant manager Clive Hendry was crushed between workboat Beinn Na Caillich and a large barge while attempting to cross between them.