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Skretting and Andfjord’s journey to advance closed aquaculture systems

The companies are innovating to achieve the optimal synergy between biology and technology in Andfjord’s land-based systems and unlock the full potential of Atlantic salmon.

Andfjord Salmon
Credits: Andfjord Salmon

Norwegian salmon farmer, Andfjord Salmon, is working with Skretting to develop a salmon feed adapted for Andfjord’s closed aquaculture system (CAS).

Located far north in Norway’s Arctic archipelago of Vesterålen, on the island of Andøya, Andfjord Salmon has developed an innovative shore-based aquaculture farming system for Atlantic salmon. The company’s ambition is to build and operate the world’s most sustainable aquaculture facility of its kind.

Skretting became involved during the early stages, as Andfjord began constructing its first land-based pool and evaluating feed suppliers. “We found Skretting to be more than a feed supplier – they are a feed collaborator,” said Christian Halmøy Torgersen, COO of Andfjord Salmon.

Developing feed for CAS is complex. Beyond meeting the nutritional needs of the fish, other environmental factors, including water flow, temperature and waste collection systems, must be considered. The CAS concept Andfjord uses is based on laminar flow and low current, which enables them to collect feces and other particles on the bottom of the tank with remotely operated vehicles (ROVs). But this also posed some challenges.

“With our first batch of feed, we weren’t getting the appetite we wanted from the fish. Because we have a low flow of water through the pool, the feed pellets were falling straight down. With a depth of only 15-16 meters, the fish couldn’t catch the feed before it sank to the bottom.”

They worked closely with Skretting to develop “floating pellets,” or, more accurately, pellets with a slower sinking speed. “We were able to increase feeding by 60% in only three days,” said Christian. In addition, the use of a Skretting recirculation component, a feces binder that leads to more structured and water-stable feces, in the feed helped them achieve lower turbidity and collect more sludge per kilogram of feed.

The slower sinking feed also enabled smaller fish to eat more food, reducing weight variations and leading to better results at harvest. “When we introduce health feeds, like skin care feed, more fish are able to access it. I think this is one of the reasons we had no wounds during the whole winter,” Christian said.

Results showed that Andfjord’s first production cycle achieved a survival rate of 97.5%, a feed conversion ratio (FCR) of 1.05, and low energy use – just 1 kWh per kilo of salmon produced. These results aligned with Andfjord’s commitment to sustainability, a value shared by Skretting. “Our mission to do fish farming with a clear conscience and sustainably is a good match with the way Skretting thinks about not just producing feed but doing it in a sustainable way,” Christian said.

Innovating together

As the collaboration continued, Andfjord was keen to use novel ingredients with a higher sustainability value. “We wanted a higher omega-3 content in the feed, but instead of using fish oil, decided to use algae oil, and Skretting was very willing to support this,” Christian said.

They also wanted to try Calanus in the feed, a natural prey species for salmon that can be harvested locally. “We used it as an alternative protein source and an attractant, and it worked tremendously well,” said Christian.

Now, amid a huge expansion project, Andfjord is preparing to release smolt into their new pools later in 2025. Skretting continues to support the company as it grows and innovates. “We’re doing our own light regimes and looking at hydrodynamics and a new technology for distributing the feed,” Christian said.

Truls Dahl, commercial director for CAS at Skretting Norway, said that Skretting's early involvement, along with a strong sense of partnership, has been beneficial for both parties. "Our close relationship with Andfjord is a great example of customer intimacy. By joining them so early on in their journey, we became deeply acquainted with their issues, which allowed us to craft effective solutions together. This also provided us at Skretting with an opportunity to gain valuable experience that we were able to use in developing our CAS feeds."

Christian believes the two companies have much more to achieve together. “Salmon today has enormous potential, and that’s the most valuable thing about land-based farming. There are so many possibilities to realize the full genetic potential of the fish. For us, it’s not just about producing salmon, but about finding the right solutions for the whole industry.”