Salmon farmers in Norway and Scotland look to the future with investments in semi-closed and closed containment technologies, writes Jenny Hjul in this month’s round-up of industry news

The Scottish salmon farming sector approaches the end of 2025 with grounds for optimism after a year of relatively low prices and continuing environmental challenges.

Exports for the year are expected to reach £1 billion for the first time, with international sales rising by 33% to £941 million in the rolling 12 months to the end of June.

The sector is now worth nearly £1 billion to Scotland’s economy, according to an independent report commissioned by Salmon Scotland, a 25% increase over the past four years.

The new survey, conducted by BiGGAR Economics, also found that average salmon wages are around £44,500, generating at least £37 million in tax last year, with more contributed by the supply chain, Fish Farming Expert reported.

Salmon, both domestically produced and imported, remains the UK’s favourite fish, accounting for almost a third of all fish sales, and making up 32% of the £4.77 billion spent on seafood in Britain and Northern Ireland.

Producers would like to grow more to meet the demand and will be watching next May’s Scottish elections closely to see if the incoming government (current polls are predicting a fifth term for the SNP) will support the sector’s clamour for long awaited regulatory reform.

Salmon Scotland has issued manifesto wish lists to all political parties, with greater regulatory efficiency the priority as always.

Post-smolt success

Meanwhile, companies continue to invest in measures to boost production and address fish health issues. Mowi Scotland reported strong Q3 results in November, with increased harvest volumes partly driven by increased smolt stocking.

The company’s post-smolt operation in low salinity Loch Etive, which Mowi acquired from trout farmer Dawnfresh in early 2023, has delivered a ‘steady rhythm of two outputs per year’, said Mowi, with sea lice levels very low and post-smolt survival high.

Two sites in Loch Awe, also bought from Dawnfresh and upgraded with new equipment, will provide five million large smolts per year, providing a further supply source for Loch Etive.

Mowi sold other Dawnfresh assets, including two trout hatcheries and a net pen trout farm, plus its own Ardnish site in Loch Ailort, to a new company, SeaQureFarming Ltd, founded by Gael Force Group owner Stewart Graham, earlier this year.

In November, the venture was awarded more than £1.8 million by the Scottish government to part-fund a pioneering semi-closed containment trout farm project at Ardnish, which Mowi had already transitioned from salmon to trout.

The farm will be an innovation site where trout will be reared in a semi-closed Gael Force SeaQureFarm unit – known as a SeaQureWell. The total cost of the system is £4.6 million and Graham hopes the reduced environmental impact of the unit, which he expects will be installed next year, will enable SeaQureFarming to increase biomass on the site.

Closed containment

In Norway, salmon farmers Lerøy Seafood Group and SalMar, which jointly own Scottish Sea Farms, are investing in closed cage technology, together purchasing six Aquatraz C2 cages. Both companies have previously operated Aquatraz systems from Seafarming Systems, reported Salmon Business, but the new units represent the next phase, being fully closed, and will double Norway’s production volume using closed technology when they are stocked in 2027.

Both the salmon companies stressed that the innovative systems will not replace traditional open net pen farming, which will continue to be the bedrock of the Norwegian salmon sector.

But the industry and the Norwegian government are exploring various alternative farming models to address environmental pressures in marine sites. In October, fisheries minister Marianne Sivertsen Næss announced a ‘flexibility scheme’ that will allow farmers to reclaim their lost biomass in the ‘red light’ zone of Western Norway, but only if they use closed containment technology to rear their fish.

Mowi has also bought into the closed containment trend, ordering four more closed fish farms to be deployed in Western Norway and bringing 2.6 withdrawn licences back into use in the region. Mowi already has six closed facilities in operation in Western Norway.

The new units are reported to be Protectus closed aquaculture systems on order from FiiZK, which expects to have 24 such installations in total delivered by the end of the year, of which 14 are currently in operation. The company says there have so far been no reported cases of sea lice or escapes in these units.

Another salmon producer, Cermaq, has taken delivery of an Aquafarm Equipment closed unit, a huge pen comprised of modular glass reinforced plastic sections, at its Horsvågen, Northern Norway, site, Fish Farming Expert reported.

And Nordlaks, which already operates the giant steel ship-shaped Havfarm, named Jostein Albert, is awaiting the arrival of its new semi-closed containment ‘Big Boat Egg’ (Storbåtsegget in Norwegian).

The pen, built in Turkey, is designed for a maximum permitted biomass of 3,120 tonnes and has a sealed roof and walls down to 20m below sea level to prevent lice and disease microbes.

Vaccine holy grail

While manufacturers devise innovative technical solutions to parasites and pathogens, scientists say they are making ‘meaningful progress’ on salmon farming’s holy grail, a sea lice vaccine, Intrafish reported.

Pharmaq and other international research institutions believe there has been a sharper research focus in the past decade and the global push for a vaccine has gained momentum.

Pharmaq is pursuing multiple vaccine concepts, leveraging both Norwegian expertise and parent company Zoetis’ global R&D network of more than 1,500 researchers.

‘Several vaccines are showing positive effects in lab conditions,’ said a professor from the University of Bergen which has spent 15 years building knowledge about the parasite.

The University of Chile is also reporting progress and a multidisciplinary team of scientists led by Dr Sean Monaghan at Stirling’s Institute of Aquaculture is working on a project to develop an oral vaccine.

Phamaq is investigating various vaccine designs and delivery methods, though injection remains the most likely route. Pharmaq research director Simen Kristoffersen told Intrafish: ‘It’s difficult, but we will get there.’

Keep up to date with the industry’s top stories, all in our next news review.