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Upfeed is a sustainable aquaculture project founded by three master's students from DTU's Tech Entrepreneurship program. We develop natural feed additives for farmed fish by upcycling nutrient-rich brine - an abundant but underutilized by-product. We process this into a functional ingredient that improves feed efficiency through reducing feed waste and therefore boosts farm profitability. Currently, many marine byproducts such as brines are considered waste and usually discarded, establishing one of the biggest waste streams in the fish farming industry.
We chose salt-cured herring brine as our starting point, given its high resource potential and Upfeed’s exclusive access to a significant herring brine stream (see key assets below).
Aquaculture feed costs represent up to 70% of production expenses in global aquaculture, making them the sector’s largest operational cost (Frontiers in Sustainable Food Systems, 2024). About 80% of farmed predatory fish diets are plant-based (DTU Aqua, 2025). However, these diets often lack essential nutrients for carnivorous species, causing reduced growth, increased disease risks, and ultimately lower fish production - resulting in significant financial losses for producers (PMC, 2022; IMARC Group, 2023).
The European aquaculture feed market is substantial and rapidly expanding. In 2023, EU aquaculture output neared 1.1 million tonnes, generating roughly €4.8 billion in value (IMARC Group, 2023; Eurostat, 2023). The European aquaculture feed market was valued at USD 45 billion in 2024, with a projected CAGR of 5.8% through 2033, fueled by fish farming growth and sustainability demands (IMARC Group, 2023; MarketReportsWorld, 2024). Denmark is a leading European producer, with 2023 aquaculture valued at about 6 billion DKK across nearly 200 licensed farms, contributing significantly to a seafood export market that reached 29.3 billion DKK in 2024 (Danish Ministry of Food, Agriculture & Fisheries, 2024; Danish Agriculture & Food Council, 2025).
Despite growth, about 80% of predatory fish diets remain plant-based and nutritionally inadequate for species like salmon and sea bass (DTU Aqua, 2025). This results in biological inefficiencies such as slower growth, higher mortality, and compromised immunity (PMC, 2022; WUR, 2020). Nutrient imbalances impair feed conversion and fish welfare, negatively affecting productivity (WOAH Aquaculture Health Survey, 2025). Many predatory fish lack essential fatty acids and vitamins needed for development and disease resistance, increasing vulnerability to infections and stress (Frontiers in Marine Science, 2023). Globally, millions of tons of farmed fish are affected annually, highlighting urgent demand for nutrient-enhancing feed additives like Upfeed’s solution.
Malnutrition in predatory fish leads to slower growth, higher mortality, and disease outbreaks that impose significant economic burdens on farmers. Feed additives have been shown to reduce feed costs by approximately 18% and total production costs by nearly 8%, while improving fish health and survival rates (PMC, 2022). Better nutrition increases feed conversion efficiency, enabling more biomass production with less feed, reducing waste, and improving profitability - creating a substantial opportunity for sustainable, effective aquafeed additives.
“Predatory fish such as salmon and cod face palatability challenges and health issues with plant-based fish feed. Especially with salmon, we observed that plant-based diets can lead to smaller hearts and slower organ development. Plant-based diets often lack essential nutrients like taurine and contain anti-nutritional factors that can cause gut inflammation. A key part of our R&D work at Aller Aqua focuses on exploring new aquafeed enhancers and supplements that improve the palatability and nutritional quality of our feed.” Jesper Clausen, R&D Manager at Aller Aqua Problem Discovery Interview
By transforming waste into value, Upfeed aims to create healthier fish, minimize resource waste, and foster a more circular and resilient aquaculture industry.