Fish and plants in blue-green symbiosis

On the island of Smøla in Møre og Romsdal, local salmon farmer Nekton Settefisk is busy developing an aquaponics pilot project. This emission-free mini-ecosystem combines land-based salmon farming with greenhouse vegetable production.

'We are exploring how we can turn wastewater from fish farms into a resource for growing vegetables. The wastewater contains nutrients and CO2 that would normally go to waste. In an aquaponics system, these can instead nourish plants,' says Christian Wikan, CEO of Nekton Settefisk.

Aquaponics is a method in which fish and plants live in symbiosis. Nutrient-rich waste from the fish is converted into valuable nutrients for the plants, which in turn purify the water for the fish. This allows resources to be reused to produce clean, healthy food.

The Nekton team is currently working intensively to explore opportunities and build knowledge, testing different approaches to find the right balance of nutrients and water to be exchanged between the fish farm and the greenhouses.

‘We take samples of the water used in production and analyse its nutrient content. We then compare the results with the nutrient requirements of the crops that would be most suitable to grow, such as cucumbers, tomatoes and strawberries. We have been able to carry out this work thanks to the support we received from Innovation Norway through Bionova,’ says Wikan.

Aquaponics is a relatively well-established technology, but is not yet widely used in Norway. As well as helping aquaponics gain a stronger foothold in the country, Nekton aims to go one step further by developing its own technology to utilise CO2 from the juvenile fish production facility.

‘Extracting CO2 from juvenile fish production for use in greenhouses as part of an aquaponics system will be a new approach, and we will probably be the first to do this in Norway,’ says Wikan.

Nekton aims not only to produce salmon more sustainably, but also to supply fresh, organic vegetables to local markets. Because aquaponics is a closed ecosystem unaffected by changes in the surrounding environment, vegetables can be grown all year round.

'The vegetables are grown in a controlled greenhouse environment that remains stable all year round, using only fertiliser produced by the fish. This gives us clean vegetables that travel only a short distance to market,' Wikan concludes.

The preliminary project will be completed in spring 2024, and Nekton plans to make a final decision on whether to take the plans forward by summer 2024.