by Dr Margaret Hegwood, Corporate Engagement Manager, The Centre for Feed Innovation, The USA
Unstable supply and future shortages of wild-caught forage fish pose major risks to the aquaculture sector, particularly concerning the supply of fishmeal. In addition to supply chain risks, including rising price volatility and disruptions, the aquaculture industry’s continued reliance on a finite supply of fishmeal (FM) has far-reaching consequences. The majority of the world’s fisheries are either overfished or maximally fished. Aquafeed’s demand for wild-caught forage fish also competes directly with human consumption, threatening food security. As demand grows amid increasingly restrictive fisheries quotas and persistent climate impacts, sustaining aquaculture production will require an estimated 1.8 million tonnes of alternative ingredients annually, leading up to 2050.
Single-cell proteins (SCPs) are well-positioned to support this transition. As a safe, sustainable and protein-rich alternative to fishmeal, they are nutritionally validated and can replace meaningful levels of fishmeal in aquafeed while maintaining or improving fish health. They also decouple aquaculture production from wild-capture fisheries and require substantially less land than traditional alternatives such as soybean meal. Crucially, their production builds on fermentation technologies that have been deployed safely across several industries, including animal feed, for decades. Together, these qualities make SCPs a reliable, cost-effective and resilient alternative to fishmeal. Realising that potential, however, means building on these foundations to overcome challenges related to capital intensity, feedstock reliance and regulatory uncertainty. How quickly the aquafeed and feed-ingredients sector can address these challenges will determine whether SCPs shift from a promising alternative to a dependable supply.
The potential of single-cell proteins in aquafeed
Single-cell proteins (SCPs) are emerging as a promising alternative to fishmeal, with early signs of commercial integration in aquafeeds. CFI estimates that current global SCP production for aquafeed was 30,000–40,000 metric tonnes (MT) in 2025. Major aquafeed companies such as Cargill and Skretting have reported including SCP in selected commercial formulations. While current uptake is modest, early uptake by major players in the aquafeed industry signals that SCPs have credible potential to scale as a key protein ingredient. This potential is bolstered by several key aspects of SCPs and their production.
First, SCPs are nutritionally validated. SCPs can replace up to 100 percentof fishmeal in shrimp feeds and up to 50 percent for some fish species, while maintaining or improving growth, health and feed efficiency. When fish are fed SCPs, particularly microalgae, the final fillet product can also have improved flesh quality, colouration and pigmentation.
SCPs are also completely decoupled from marine supply chains, providing a safe, nutritious alternative while minimising the supply chain risks conventionally associated with marine ingredients. Further, SCPs can have emissions comparable to those of fishmeal, especially when produced using industrial sidestreams or agricultural byproducts. And although they use more land and water than fishmeal, they use much less than other conventional land-based sources of protein, such as soybean meal.
SCPs are also produced in established safety frameworks and familiar production systems. Despite the novelty of some SCPs in aquafeed, several yeast and fungal species have a long history of safe use in animal feed. Further, industrial fermentation is a well-established technology across the food, feed and biotechnology sectors. Several SCP products (e.g., bacterial proteins) have received regulatory approval in major markets and feeding trials across species demonstrate consistent safety, digestibility and performance.
Advances in process efficiency, feedstock utilisation and modular production models are also improving the unit economics of SCP production. In some high-value or sustainability-driven market segments, methanotrophic bacterial proteins are approaching cost competitiveness with fishmeal. Reported prices for methanotrophic SCP are approximately US$ 1500 per MT, placing them within the historical range of high- quality fishmeal, which has fluctuated between US$ 1068 and US$ 2388 per MT since 2010.
Based on technological advances, announced investments and industry forecasts, CFI estimates that SCP production could reach between 150,000 and 500,000 MT by 2030, representing more than a tenfold increase in five years. Achieving this scale and commercial uptake would have enormous benefits for the aquaculture industry and marine ecosystems. Under best-case scenarios, one tonne of SCP can replace the protein from six tonnes of wild-caught fish but achieving this growth will also require the sector to overcome several barriers, most notably capital intensity.
Overcoming CapEx barriers to scale SCP production
Commercial SCP plants are highly capital-intensive, and scaling SCP supply is constrained by high capital costs. Small-scale (~20,000 MT/year) SCP production facilities are highly capital-intensive, requiring roughly US$ 10,000–12,000/MT of investment. Regardless of production volume, infrastructure such as multi-stage gas handling, compression and fermentation tanks must be installed and cannot be proportionally reduced at lower throughputs. This fixed-cost burden creates challenges in producing sufficient volumes to meet aquafeed formulators’ needs. Like many capital-intensive industries, SCP producers risk being left in the ‘missing middle’ – too capital-intensive for venture capital and too nascent to be considered an infrastructure investment.
Regardless, SCP’s show very promising unit economics at scale. Larger facilities (~100,000 MT/year) can reduce upfront capital investments by 75 percent to below US$ 3000/MT, maximising both return and impact. Still, these larger facilities require substantial upfront capital and further expansion will depend on bespoke funding models.
Industrial joint ventures, sometimes with additional government support, have shown promise as an investment model for scaling SCP production. In 2020, Calysta and Adisseo formed a joint venture, Calysseo, to construct a 20,000 MT SCP production facility in Chongqing, with plans to expand capacity by 80,000 MT. More recently, Unibio formed a joint venture with the Saudi Industrial Investment Group (SIIG) to build an initial 50,000 MT SCP production facility with plans to scale to 300,000 MT in the coming years. These joint ventures spread investment risk and benefit from co-location with industrial inputs and government support.
Performance at scale is strongly affected by how fully the plant is used, how efficiently it produces biomass and local operating costs. While larger plants can spread fixed costs over more output, some expenses, especially drying, downstream processing and feedstocks, depend heavily on local electricity costs and feedstock availability. Co-location with low-cost energy and feedstock sources and the development of efficient processes are therefore also decisive factors in determining competitiveness and environmental performance.
The future of SCPs in aquafeed
Achieving sustainable growth in the aquaculture sector will require alternative ingredients that reduce reliance on marine ingredients such as fishmeal. In the coming years, the rising supply of SCPs is well-positioned to supplement fishmeal in commercial aquafeed formulations, thanks to their safety, sustainability and stability benefits. However, their long-term contribution will depend on the industry’s ability to overcome barriers to scale, especially securing new investments in production facilities. Scaling the supply of SCPs will require continued investment, innovation and collaboration across the value supply chain to achieve cost reductions and expanded production capacity. If these challenges are addressed, the potential of SCPs as a sustainable and resilient feed ingredient can be fully realised.
