From salmon sludge and manure to fertiliser: a circular economy around land-based salmon farming

ongoing

Human population is growing, and neither aquaculture nor agriculture are adapting to overcome this challenge sustainably. On the one hand, fish production must increase, but sea-pen aquaculture is facing pollution and spreading of disease and water eutrophication. On the other hand, animal manure is the primary source of ammonia emissions and nitrate leaching. Fertilisers are needed to ensure food security. However, raw materials imports are limited, fertiliser production processes are high-energy intensive (2% of the world’s energy), and phosphates scarcity has raised fertiliser prices by 80% in the last year. Terraforming LIFE designs and develops new technologies and methods to create an Integrated Agriculture Aquaculture (IAA) system where aquaculture, agriculture farmers, and agriculturists are at the heart of a circular economy. This project optimises a new water recycling technology (Sideflow), complementary to the “Flow-Through System with Reuse” (FTS-R) aquaculture system. Both CAPEX and OPEX will be lower below any other high-tech aquaculture system (e.g., sea-pens, Recirculation Aquaculture System (RAS), and hybrid systems) while maximising the amount of nutrients of fish sludge. A combination of processed sludge and animal manure will be transported by a mobile treatment unit to a bio-fertiliser plant. Lastly, it will be boosted with digestate from any dead-fish that unavoidably perish during the rearing, and eventually dried to create a powerful natural fertilizer and biogas. Within five years beyond the end of the project, we will implement 6 IAA systems (one in Iceland and five more across Europe), generating 138 new FTE and € 3.9 bn of revenue - based on 0.5 Mt of salmon sales, and 1.08 Mt of bio-fertiliser sales (0.82 Mt of landfilled manure and 0.25 Mt of salmon sludge). This project will reduce 1.04 Mt of CO2 eq by shifting production from mineral to bio-fertilisers and avoid 0.08 Mt of CO2 eq due to ammonia evaporation from landfilled manure.