What can replace fish meal?

November 20, 2025 •

4 min read

As aquaculture now provides more than half of the fish consumed globally, the traditional reliance on fish meal from wild-caught stocks has raised significant sustainability concerns. The industry is rapidly adopting innovative solutions for what can replace fish meal to reduce pressure on marine ecosystems and ensure a secure, sustainable food supply for the future.

Quick Summary

Several sustainable alternatives are emerging to replace traditional fish meal in aquaculture. These include plant-based sources like soy and rapeseed, high-protein insect meals, nutrient-rich algae, and innovative single-cell proteins derived from microbes. These alternatives mitigate overfishing impacts and enhance feed efficiency.

Key Points

Diverse Alternatives: Options like plant-based proteins, insect meal, algae, and single-cell proteins offer sustainable and nutritionally viable replacements for traditional fish meal.
Technological Advancements: Processing methods such as fermentation, enzymatic treatment, and genetic engineering are key to overcoming the limitations of plant proteins and maximizing the potential of novel alternatives.
Circular Bioeconomy: Insect meal and single-cell proteins, in particular, promote a circular economy by utilizing organic waste streams and even greenhouse gases to produce high-quality feed ingredients.
Species-Specific Formulas: The success of alternative feeds depends on tailoring formulations to the specific nutritional needs of different fish species, mitigating issues like anti-nutritional factors and low palatability.
Environmental Benefits: Reducing reliance on wild-caught fish for feed helps protect marine ecosystems, while many alternatives offer a lower carbon footprint and reduced environmental impact.
Economic Viability: As costs for traditional fish meal rise, the increasing availability and improved production of alternative protein sources present more cost-effective solutions for the aquaculture industry.
Nutrient Biofortification: Technologies can be used to biofortify single-cell proteins and other feeds with essential nutrients like omega-3 fatty acids, further enhancing their nutritional value.

The search for reliable, sustainable, and cost-effective alternatives to fish meal is a top priority for the global aquaculture industry. Driven by increasing demand for seafood and fluctuating prices of traditional feed, researchers and farmers are turning to diverse sources to meet the nutritional needs of farmed fish.

Plant-Based Alternatives

For decades, plant-based proteins have been the most widely used alternative to fish meal due to their availability and affordability. However, their use requires careful formulation to overcome inherent nutritional limitations.

Types of plant protein meals

Soybean Meal (SBM): The most common plant protein source, offering a balanced amino acid profile and high protein content. It is widely used in diets for omnivorous species like tilapia and carp. However, it contains anti-nutritional factors (ANFs) like phytates and protease inhibitors that can impact digestibility and intestinal health in some carnivorous fish.
Rapeseed (Canola) Meal: A cost-effective, domestic plant protein source in many regions, especially Europe. It is a good source of protein but contains ANFs like glucosinolates, which can affect feed palatability and fish health. Processing techniques like fermentation and the use of phytase enzymes can improve its nutritional value.
Cottonseed Meal (CSM): A byproduct of the cotton industry, CSM is protein-rich but contains the toxin gossypol, which limits its inclusion levels in aquafeeds. Modern processing methods produce low-gossypol meals, improving its safety and utilization.
Pea Protein Concentrate (PPC): Offers high protein and low ANF content, making it a promising option, particularly for carnivorous species. It is used in premium feed formulations.

Insect Meal

Insects offer an eco-friendly and nutritionally compelling alternative to fish meal, leveraging the principles of a circular bioeconomy.

Key insect species and benefits

Black Soldier Fly (BSF) Larvae: A fast-growing insect species that can be reared on agricultural waste, providing a high-quality protein and lipid source for fish feed. BSF meal has been shown to enhance fish immunity and is suitable for species like salmon, shrimp, and tilapia.
Yellow Mealworms: Rich in protein and fat, mealworms can be cultivated efficiently and have demonstrated positive effects on fish growth and immune response.
Earthworm Meal: Known for its high protein content and good palatability, earthworm meal has been used as a fish meal alternative with promising results.

Addressing chitin challenges

Insect exoskeletons contain chitin, a polysaccharide that can affect feed digestibility. Research into exogenous enzymes, like chitinase, and specific fermentation methods is helping overcome this challenge, unlocking more of the nutritional potential of insect meal.

Algae and Single-Cell Proteins (SCPs)

Algae and SCPs represent some of the most innovative and sustainable solutions for replacing fish meal, providing essential nutrients and functional benefits.

Algae-based feeds

Microalgae and macroalgae (seaweed) are rich in protein, essential fatty acids (including omega-3s), and other valuable compounds.

Microalgae (e.g., Spirulina, Chlorella): A source of high-quality protein and lipids, particularly omega-3 fatty acids, which are crucial for fish health. Algal oils can directly replace fish oil, improving the nutritional profile of farmed fish.
Macroalgae (Seaweed): Provides vitamins, minerals, and fiber, and can also offer prebiotics and immunostimulatory properties.

Single-cell proteins (SCPs)

SCPs are derived from microorganisms like bacteria, yeasts, and fungi and offer a highly sustainable protein source.

Bacterial SCPs: Produced by bacteria like Methylococcus capsulatus using waste materials or methane as a feedstock. These proteins have excellent nutritional profiles and can reduce greenhouse gas emissions.
Yeast SCPs: Rich in protein and vitamins, yeast biomass is a valuable feed additive that can enhance fish immunity and gut health. Some yeast products are produced from ethanol fermentation byproducts.

Comparison of Major Fish Meal Alternatives


Feature	Plant-Based Proteins (e.g., Soy, Rapeseed)	Insect Meal (e.g., BSF, Mealworm)	Algae (Microalgae/Macroalgae)	Single-Cell Proteins (SCP)
Protein Content	35-50%	40-60%	Up to 70% (e.g., Spirulina)	30-70%
Sustainability	Variable (land use, deforestation concerns)	High (utilizes organic waste, low footprint)	High (minimal land/water use, waste recycling)	High (utilizes waste streams, captures GHG)
Cost	Relatively low	Becoming competitive, depends on scale	Historically high, decreasing with technology	Competitive in some cases, scalable
Digestibility	Varies by source, can be limited by ANFs	Generally high, but chitin can be a factor	High (lack tough cell walls of terrestrial plants)	Generally high, good nutrient availability
Key Challenges	ANFs, amino acid imbalance, land use competition	Scaling production, processing costs, chitin digestibility	High production costs, harvesting, strain stability	Cost, scalability, public perception, regulatory approval

Improving Plant Protein Utilization

To maximize the benefits of plant-based ingredients and mitigate their drawbacks, several strategies are employed. Fermentation, using microorganisms like bacteria or fungi, can break down complex compounds and reduce ANFs, improving palatability and digestibility. For instance, fermented soybean meal shows improved performance in many fish species. Enzymatic treatments, such as adding phytase, can increase the bioavailability of minerals like phosphorus, which are often bound up by phytates in plant material. Finally, amino acid supplementation is used to balance dietary profiles, adding key limiting amino acids like methionine and lysine.

Conclusion: A Diverse and Sustainable Future

The move towards diversified feed ingredients is essential for the sustainable growth of aquaculture. The golden standard of fish meal is no longer a necessity for carnivorous fish, with research proving they can thrive on fish-free diets. A combination of alternatives, from refined plant proteins to novel insect, algae, and single-cell proteins, offers a more resilient and environmentally responsible approach. As technology improves processing techniques and lowers costs, these alternatives will not only provide balanced nutrition but also contribute to a circular, resource-efficient food system for a growing global population. You can learn more about the transition to sustainable aquafeeds from authoritative sources like NOAA Fisheries.

Frequently Asked Questions

The most widely used plant-based protein source in aquaculture is soybean meal due to its high protein content and cost-effectiveness, although it requires processing to manage anti-nutritional factors.

Yes, insect meals, particularly from black soldier fly larvae and mealworms, are highly promising. They offer a high protein content, can be produced sustainably on organic waste, and have demonstrated positive effects on fish growth and immunity.

Yes, microalgae can be an excellent source of high-quality protein and essential omega-3 fatty acids, which are traditionally sourced from fish oil. Technological advances are making algae-based feeds more viable.

SCPs are proteins derived from microorganisms like bacteria, yeasts, and fungi. They are produced through fermentation using various feedstocks, including waste products, and can be incorporated into aquafeeds to replace fish meal.

Plant proteins contain anti-nutritional factors (ANFs) that can impair digestibility and potentially cause intestinal inflammation in some fish species, especially carnivores. However, processing techniques like fermentation and enzyme supplements can mitigate these effects.

Yes, research has shown that fish, even carnivorous species, can be fed diets containing no fish-based ingredients. This is achieved by carefully blending different alternative protein sources and supplementing with necessary nutrients.

Processing techniques such as fermentation, enzymatic treatment with additives like phytase, and supplementing with specific limiting amino acids are used to improve the nutritional quality of plant protein sources.