The first salmon to be raised in Scottish Sea Farms’ smolt hatchery at Barcaldine, on the west coast of Scotland, were harvested in November last year from the company’s Loch Nevis C farm.
It was a major milestone for Scottish Sea Farms (SSF), which had invested £58m in the Barcaldine site. Taking up 17,500 square metres, the hatchery has the capacity to produce as many as 10 million smolts annually, and crucially, it gives the freshwater team the ability to grow bigger, more robust smolts that require up to two months less at sea.
For the first generation of smolts which transferred from Barcaldine in December 2019, this means they had reached an average weight of 160g on transfer, more than double the typical weight of smolts that are produced using a traditional hatchery process.
For the first generation of smolts which transferred from Barcaldine in December 2019, this means they had reached an average weight of 160g on transfer, more than double the typical weight of smolts produced using a traditional hatchery process.
Barcaldine represented a major investment for SSF, so what was the motivation? Pål Tangvik, Freshwater Manager at the company, explains: “Our motivation was two-fold. Firstly, we wanted to become self-sufficient in smolt production for our growing estate of marine farms. Secondly, by opting for a recirculating aquaculture system (RAS), we wanted to gain more control over key factors such as water quality, temperature, oxygen levels, light and speed of flow so that we could create the optimum growing conditions.”
Previously, SSF had grown its own smolts at three smaller, flow-through hatcheries in Scotland, meeting any surplus requirements via third parties.
Using the latest recirculating aquacultural systems (RAS) technology, Barcaldine requires 20 times less freshwater than conventional methods and employs a combination of energy-efficient heat pumps and heat exchangers to maintain and adjust water temperature; a system that can also recover energy from waste water so that it can be reused elsewhere in
the process.

Pal Tangvik. Photo: Scottish Sea Farms

Furthermore, the hatchery uses a filtration system to capture waste, which is treated and re-purposed as fertiliser for land farming rather than ending up in the marine environment.
One of the toughest tasks, says Tangvik who oversaw the project to completion, was to find the right location for the land-based facility: “We wanted to be close to the sea so we could transfer the fish directly onto the wellboat then on to the marine farm, without the need for road or air transport; a key advance for fish welfare. And we needed water to be available – Barcaldine already had a hydro-electric installation which met some of our power and water needs.”
He adds: “The hatchery uses a lot of energy, but it needs much less energy per fish produced than conventional hatchery methods.”
Increasingly, other farming businesses are making this kind of investment, in Scotland, Norway and elsewhere. As Tangvik observes: “More and more companies are seeking to gain greater control over their production methods. We all have the same goal of giving the fish in our care the very best journey.”
Recently, SalMar announced it was working with RAS specialist Krüger Kaldnes and construction firm Consto to build what it says will be the world’s biggest smolt hatchery at Tjuin in Malm, Norway. The building work begins in May of this year.
Meanwhile in Canada, Cooke Aquaculture is planning to invest nearly CAN $60m dollars building a new post-smolt hatchery in Digby Neck, Nova Scotia. The land based hatchery is planned to produce three million salmon a year, supplying Cooke’s 13 fish farms in the province. Here too the fish will be kept longer before being transferred to marine sites, reaching an average 500g.
One of the key benefits of a RAS hatchery is that it becomes possible to keep production going throughout the year. So says Lars Halvorsen, Project Manager with Norway’s Alvestad Marin AS.
He says: “The advantage is that you can have a more controlled environment, which is less dependent on the seasons and on local water sources. It makes it possible to have continuous production.”
Alvestad specialises in RAS technology for hatcheries. The company began in 2002 with salmon hatcheries using flow-through technology, before developing a fully RAS approach using more complex water treatment.
The company sees significant opportunities in the growth in land-based salmon production internationally. He says: “Salmon are now being farmed in many places throughout the world, so they will need hatcheries!”
The big land-based farm projects under way now have financial muscle, but they also need to make use of expertise and this typically comes from Denmark and Norway, he notes.
The land-based division of aquaculture technology business AKVA group has around 300 employees, mainly based in Denmark, Norway and Chile. Jacob Bregnballe, Sales Director, Land Based Salmon Projects, says the company has been working on RAS projects to grow salmon to harvest size for several years now.
He says: “It’s a proven technology – we have shown that it works with smolts, so applying it to adult fish is more about size [of the system] than anything else”.
“This market is growing. We’re working on five or six big projects, with capacities of 5,000, 10,000 or even 15,000 tonnes annually, and all of them are going through to execution.”
AKVA group’s current projects include sites in Middle East, Norway, Sweden, USA and in China, where AKVA group is working with Nordic Aqua Partners and feed supplier Nutreco on an 8,000 tonne RAS facility in Ningbo.
Why is there increasing interest in land-based farming worldwide? Bregnballe says there are a number of drivers. One is that, by locating large firms close to consumers, it is possible to cut the costs of transport, and also reduce CO2 emissions. With land-based farms it is possible to grow salmon in locations where the marine environment is too warm, or otherwise unsuitable, or where public policy has decreed – as in Denmark recently – that further marine fish farm development should not be allowed.
Another argument is sustainability and environmental impact. AKVA group is working on a facility in Sweden that will be owned and run by Premium Svensk Lax (PSL), a Swedish company committed to a zero-emissions
approach. The farm will have 88 tanks to accommodate different growth stages from first feed to big grow-out tanks, powered by renewable energy. The fish waste will be collected and used for biogas.
Bregnballe says: “10 years ago the technology focused on water treatment, such as biofilters. We have learned how to build big biofilters and we understand RAS technology. Now we are looking further than the RAS itself: for example, how do we handle large salmon? We are developing systems to move and grade fish even up to 5kg, 6kg. How do we feed the massive amounts of salmon in large RAS systems? These projects are of interest to the big feed companies because they want to gain knowledge about what is exactly needed to feed this generation of land-based salmon.”
Consultants Kontali forecast that, by 2030, worldwide salmon production will go up from 2.6m tonnes to 4.5m tonnes, of which AKVA group estimates that 800,000 tonnes will be land-based.
Bregnballe says: “It’s a large market. You can get a premium product this way and the cost will come down as we find ways to do it better. It’s a completely new way of looking at aquaculture, and there is a lot of interest from investors in the sector. It’s not money that’s the challenge, it’s the ability to execute.”
Even now, however, not all land-based developments use RAS technology. Kvarøy Arctic operates several marine farms off Kvarøy island, part of an archipelago on the edge of the Arctic Circle. The company’s sites are located in deep water, open ocean, sites where the water quality is excellent and the temperature ideal for salmon.
Under Norway’s “traffic light” system, the area is counted as “green” but even so, the capacity for any more farms in the locality is extremely limited. That’s why, according to Kvarøy’s Chief Executive Officer, Alf-Gøran Knutsen, the company is building a land-based farm.
He explains: “There is no more space [at sea], but we want to produce more and we see advantages in terms of where we are located.”
Logistical issues such as feed and harvesting are also easier with a farm located close to the existing sites. The solution, for Kvarøy, is a land-based farm using “flow through” technology, making use of the abundant and clean seawater in the area. The Kvarøy site will recirculate only 40-50% of the water it uses – in contrast to a RAS facility which could typically recirculate up to 98% – and it does not require expensive filtration systems and chemicals.
The flow through system uses more energy than a RAS, but it is connected to a renewable hydro-electric source. Also the capital expenditure required is lower. Following “circular economy” principles, fish waste will be collected and reused to create biofuel to power Kvarøy’s wellboats and trucks. Another advantage is that the Kvarøy system can keep the fish in self-contained units, so if there is a disease outbreak in one it will not affect the others.
Knutsen stresses: “We’re not in a hurry – we don’t have investors who want their money back straight away. We are on track to have the first fish in the tanks in 2023, for harvesting in late 2023 or early 2024.”

How Kvaroy’s flow-through installation will look

Advances in land-based farming have been impressive, but it should never be forgotten that at the heart of the system is a living organism.
Professor Herve Migaud, of the University of Stirling’s Institute of Aquaculture, says: “A huge amount of work has gone into developing RAS technology – which has been fantastic over the last 20 years – but there has not been enough study yet to understand the impact on biology.”
Migaud is co-ordinator for the Robust-Smolt project. Launched in January 2019, the aim is to understand the biological implications for smolts reared in RAS facilities. It is intended to continue through 2021.
The initiative is a collaboration between the University of Stirling, (which is leading the project) and academic staff at Aberdeen, Edinburgh and Exeter Universities, together with the leading players in the fish farming sector in Scotland and trade, corporate and government organisations.
Migaud notes: “There are clear environmental, welfare and production benefits with RAS. For example, fish in RAS facilities are protected against pathogens, their environment is fully controlled and environmental impact reduced.”
He adds, however: “We wanted to understand anecdotal reports that smolts transferred to sea from RAS are not doing as well as those from ambient loch systems. Practice in Scotland offers a unique opportunity given that smolts are produced in both environments. In a way it makes sense; RAS provides a very constant and consistent environment to the fish which contrasts with sea conditions characterised by daily and seasonal changes in photoperiod, with darkness not really experienced in RAS, and tides, cooler temperatures, depth. Fish would benefit from a period of acclimatisation prior to transfer as seen for other species.
“Another question was whether fish immunocompetence in RAS is different than in ambient systems. Early results from the project show that the microbiome in RAS fish – the collection of micro-organisms on the fish mucosal layers like skin, gills and intestine – is different from that of fish from ambient loch systems. However, the potential long term effects remain to be understood and the saline environment has been shown to reset the microbiome”.
Migaud and his colleagues are also looking at the impact of water chemistry, genetic factors, diets. He says: “This is an ambitious project given the wide range of factors at play and it is too early for conclusions from the project, many more questions and hypotheses remains to be studied during the years to come!”
With the growth of land-based fish farming, aquaculture is embarking on an exciting and challenging new phase. Whether it turns out to be successful in the long term will depend on a number of factors , such as technology and the price of fish, but there is no doubt at all that considerable resources are being committed to growing the sector.

Professor Herve Migaud, Institute of Aquaculture, University of Stirling

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