The aquaculture sector in Trøndelag generates more than one million tons of sludge annually, primarily from food fish production. The sludge consists of feed residues and fish excreta and contains substantial amounts of nitrogen, phosphorus, and carbon.
Despite this, approximately 84% of the resource remains unutilised, representing significant potential for increased circular value creation with both economic and environmental benefits.
Currently, sludge is mainly collected from land-based facilities and used for biogas production, fertilisers, and compost—solutions that offer limited upgrading into high-value products. Biological approaches, such as the cultivation of low-trophic organisms, have demonstrated the ability to convert both organic and inorganic material in sludge into high-quality biomass, which can be used, for example, in fish feed and other bio-based products.
Although extensive knowledge exists in this field, there is a clear need to make this knowledge more accessible and applicable for actors across the value chain.
This project therefore builds on existing research and expertise to develop a structured and practice-oriented knowledge base for more resource-efficient treatment and utilisation of aquaculture sludge.
The project focuses primarily on low-trophic and biological processing and maps relevant processes for sludge utilisation, assesses their suitability across different parts of the value chain, and evaluates implementation opportunities, technological maturity, and relevant regulatory and operational frameworks.
The outcome will be a structured knowledge base, disseminated through a report and a final webinar, with the aim of making research-based knowledge more operational for stakeholders seeking to develop new, profitable, and sustainable value chains based on aquaculture sludge.
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