© Finnfjord AS
At the heart of the innovation is a collaboration between ferrosilicon producer Finnfjord AS and research institutes – The Arctic University of Norway (UiT), SINTEF, Nofima. By cultivating microalgae on CO₂ emissions from Finnfjord’s smelter, the team aims to transform a major environmental challenge into a sustainable solution for the aquaculture industry.
“We incorporate the algae into the feed and conduct growth trials with the salmon, from fry to slaughter weight. It is technically challenging, but results so far show that the salmon grow well on the algae feed and are in good health,” said Sten Siikavuopio, senior scientist at Nofima, in a press release.
Algae, a nutritious source of fatty acids
Microalgae, especially diatoms, are rich in omega-3 fatty acids like DHA and EPA – nutrients essential for salmon health. With the global industry facing challenges around sustainable sources of marine oils, algae-based ingredients could provide a valuable alternative.
“Microalgae can grow quickly and produce more of the healthy omega-3 fatty acids when cultivated in large reactors at Finnfjord AS. This makes them particularly interesting as a feed ingredient,” added Siikavuopio.
The algae are grown in large tanks connected directly to Finnfjord’s exhaust system, using CO₂ from ferrosilicon production as a growth driver. Once harvested, the algae biomass is sent to feed producers at Nofima, Skretting and Cargill, who develop custom feed blends. In addition to good growth and health, scientists and fish farmers can note yet another highly positive side effect of the algae feed - microalgae in the feed also result in less salmon lice infection.
He believes algae oil has qualities that mean it could replace fish oil in fish feed. The research project AlgOpti at Finnfjord AS received NOK 93.3 million (€7.9 million) in 2021 from Green Platform – a funding scheme for new sustainable technology – to develop salmon feed using CO₂. The project will also establish methods for cultivating useful algae. Out of this, the project Mikro-fôr – Microalgae as a feed raw material for farmed fish – was born. This project is funded by The Norwegian Seafood Research Fund (FHF) and led by SINTEF Ocean.
“Previous tests where diatoms were added to standard salmon feed have demonstrated that the salmon have maintained good health throughout their life cycle on such feed. But the maximum addition of algae in feed so far has only been three percent. With the new feed we have tested, we have managed to include up to 15 percent algae in the feed. Trials so far show that the fish grow and thrive very well with a high inclusion of algae in the feed” continued Siikavuopio.
One reason for the low proportion of algae in the feed until now has been issues with water in processed algae biomass, but improved technology has now made it possible to add more algae to the feed.
