A land-based fish facility with a daily feed consumption of two tons normally has a feed wastage of 200 kilograms every day. This feed mixes with fish feces and creates sludge. To solve this issue, Nofima and Vard Aqua have developed a solution that separates uneaten feed from feces, recovering it to be reused.

Vard Aqua, which has been partnering with Nofima since 1985, is developing a commercial solution that will enable farmers to reprocess uneaten feed and convert it into a new resource. The innovation is also meant to avoid additional sludge drying processes, saving energy and producing a final mud with a higher concentration of minerals. The invention, which has been recently presented by Nofima and Vard Aqua during the conference Smolt production in the future, has been given the preliminary name of ‘spill box’.

The spill box is a result of several years of research on feed digestibility. This area of study is difficult in farmed fish where uneaten feed and feces are mixed in the water. Scientists started developing tools for the collection of feed and feces until the solution came from the bounce in the feed pellet versus the sticky properties of the feces. That allowed scientists to separate feed and feces into different fractions.

However, the tool must be further developed if it is to be used commercially but have yielded positive results at Nofima’s research station at Sunndalsøra separating uneaten feed from the wastewater so it can be recycled back to the salmon.

“We are very pleased that we get the chance to collaborate with technology suppliers like Vard Aqua so that they can take our research tool and develop it on a commercial scale. Economy and resource utilization will be the major advantages of the spill box for industry actors,” said Kjell-Åge Rognli, director of business development at Nofima.