RASTECH Magazine

Industry update News
Study uses RAS waste water to grow salad


The possibility of your next plate of salad coming from a recirculating aquaculture system (RAS) facility, could be a reality sooner than expected.

One of the latest entrants in the aquaponic research arena are European salmon faming company Columbi Salmon, global aquafeeds company BioMar, the Norwegian Institute of Bioeconomy Research (NIBIO) and aquaculture research body, Morefish.

The project, which was carried out at NIBIO Landvik’s aquaponic plant in Grimstad from December 2020 to May this year. The project uses “fish sludge” and water used in the RAS process.

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The experiment was performed with 1,000 salmon, and by cultivating the salad type “Partition”, according to Columbi. Fresh water was used since many plants are sensitive to salt, according to project manager Mari Båtnes Birkeland of Columbi Salmon.

The next step is develop a full-scale production plant that can grow salad or other vegetables in water coming from onshore fish farming.

“The salad that was grown in the aquaponics system had an impressive growth. In line with our hypotheses, we saw very encouraging results,” said  Siv Lene Gangenes Skar, a researcher at NIBIO. “Plant production with RAS means that food production can be multiplied using the same amount of water. In addition, we promote sustainable usage and protection of water and marine resources in support of the UN sustainability goals.”

Water quality, fish welfare, carbon dioxide, and plant quality, are among the factors that were analysed and carefully assessed throughout the trial period. BioMar performed a life cycle assessment (LCA) analysis of the feed given to the plant, and NIBIO performed further measurements of the carbon flow throughout the system.