Transforming CO₂ into Sustainable Salmon Feed: A Revolutionary Approach

Innovative scientists are creating healthy feed for farmed salmon from carbon dioxide (CO₂), turning an environmental liability into a nutritional resource.

Turning Emissions into Nutrition

An annual release of 300,000 tonnes of CO₂ at Finnfjord AS, a ferrosilicon manufacturer in Northern Norway, is now being captured and utilized by microalgae. These tiny powerhouses use CO₂ as an energy source, effectively ‘consuming’ it just like land plants do.

Collaboration for Change

The feed enriched with algae is produced by Nofima, the Norwegian Institute of Food, Fisheries and Aquaculture Research. Senior scientist Sten Siikavuopio, who heads Nofima’s research on this project, explains: “We incorporate the algae into the feed and conduct growth trials with the salmon, from fry to slaughter weight. Although technically challenging, preliminary results indicate that the salmon thrive on this algae-based diet.”

Zero Emissions Goals

Finnfjord AS aims for zero emissions by fully utilizing the CO₂ generated during production. This ambitious project is a collaborative effort involving UiT – The Arctic University of Norway, SINTEF, and Nofima.

Diatoms: Nutritional Powerhouses

Diatoms, a type of microalgae, are rich in essential fatty acids, an integral part of salmon feed. With increasing global demands for marine oils in aquaculture, microalgae offer a promising alternative. “When cultivated in large reactors at Finnfjord AS, microalgae can grow rapidly and yield higher amounts of omega-3 fatty acids like DHA and EPA, which are vital for salmon,” Siikavuopio adds.

Funding and Development

The research project, named AlgOpti, secured NOK 93.3 million in 2021 from the Green Platform to develop this innovative salmon feed. The project Mikro-fôr subsequently emerged, focusing on the use of microalgae as a raw material for aquaculture, with funding from FHF – The Norwegian Seafood Research Fund.

Increasing Algal Content in Feed

Previous studies limited the algae content in salmon feed to 3%. However, improved technology now allows for a higher incorporation rate. “With our new formulations, we’ve successfully included up to 15% algae in the feed, showing promising results for fish growth and overall health,” says Siikavuopio.

A Well-Developed Recipe

Finnfjord AS and UiT have created a system for channeling CO₂ emissions into algae cultivation tanks. The algae process the CO₂ to produce protein and valuable marine oil. This biomass is then sent to feed manufacturers like Nofima, Skretting, and Cargill, where it is transformed into a specialized feed blend.

Positive Impacts of Algae Feed

In addition to enhancing growth and health, the algae feed also appears to reduce infections of salmon lice, a significant issue in aquaculture. “Microalgae in the diet have demonstrated a reduction in salmon lice infestations,” Siikavuopio confirms.

Interdisciplinary Collaboration

This research project showcases a high degree of collaboration among various departments within Nofima. According to Siikavuopio, “Interdisciplinarity is at its very best in projects like this,” involving colleagues from feed technology, quality science, and fish health.

Future Research Directions

Despite the advancements, only a small fraction of microalgae species have been evaluated for aquaculture feed. “Further exploration and testing different types of algae are essential for optimizing both cultivation processes and the incorporation of marine oils into fish feed,” concludes Siikavuopio.

Facts About Finnfjord AS

• Finnfjord AS is one of the world’s most energy-efficient and environmentally friendly ferrosilicon producers.
• The company aims to be the first CO₂-free ferrosilicon producer globally.
• It operates three furnaces with a total production capacity of 100,000 tonnes per year.
• A thermal energy recovery plant installed in 2012 generates 340 GWh of electricity.
• In 2014, Finnfjord AS partnered with UiT to utilize algae for CO₂ emissions reduction.

Image: Three research environments are collaborating with Finnfjord AS to convert CO₂ emissions into nutritious salmon feed. Credit: Nofima