Can Algae Save Our Seas? Sustainable Fish Feed for a Healthier Planet

Elliot Brynn in Climate & Environment August 2025 • 4 min read.

"Discover how marine microalgae production is revolutionizing global fisheries and aquaculture, offering a sustainable alternative to traditional fishmeal and fish oil."

The world's oceans are facing unprecedented challenges. Overfishing, habitat destruction, and climate change are threatening marine ecosystems and the livelihoods of billions who depend on them. One critical issue is the unsustainable practice of using wild-caught fish to produce fishmeal and fish oil, essential ingredients in aquaculture feed.

But what if there was a better way? A solution that not only reduces pressure on wild fish populations but also provides a more sustainable and environmentally friendly source of nutrition for farmed fish? The answer may lie in the microscopic world of marine microalgae.

Recent research suggests that commercial production of marine microalgae could revolutionize the aquaculture industry, offering a viable and sustainable alternative to traditional fishmeal and fish oil. Let's dive into the details of this game-changing innovation.

Why Microalgae Could Be the Future of Fish Feed

Surreal illustration of microalgae forming a fish shape in the ocean, symbolizing sustainable aquaculture.

Fishmeal and fish oil are traditionally produced by rendering approximately 30% of the wild fish catch. However, with global fish catch reaching its maximum sustainable yield in the 1980s, annual production has stagnated at around 5-6 million tonnes of fishmeal and 1 million tonnes of fish oil. As the aquaculture industry continues to expand, demand for these ingredients is soaring, driving up prices and exacerbating the strain on marine resources.

The challenge is finding replacements that can match the nutritional profile and benefits of fishmeal and fish oil. Plant-based alternatives like soybean protein concentrate, wheat gluten, and corn gluten often require supplementation with essential amino acids. Moreover, they may contain anti-nutritional components that hinder digestion. Finding sustainable sources of n-3 highly unsaturated fatty acids (HUFAs), crucial for optimal growth and health, is even more problematic, as terrestrial plants do not produce them in sufficient quantities.

Nutritional Powerhouse: Marine microalgae boast a balanced amino acid profile and are a natural source of n-3 HUFAs, making them an ideal replacement for fishmeal and fish oil.
Sustainable Solution: Commercial microalgae production can significantly reduce pressure on wild fish populations, promoting a more sustainable aquaculture industry.
Economic Viability: Large-scale algae production facilities can generate substantial revenue and net income, making them an attractive investment opportunity.
Environmental Benefits: Microalgae production can lower greenhouse gas emissions compared to traditional fishmeal production, contributing to a healthier planet.

A study published in Scientific Reports explores the commercial aspects of producing fishmeal and fish oil replacements from marine microalgae. The researchers adapted a model based on microalgae production results in Hawaii and applied it to Thailand, the world's fourth-largest producer of fishmeal. The results are promising.

A Sea Change for Sustainability

By embracing marine microalgae as a sustainable alternative to traditional fishmeal and fish oil, we can reduce fishing pressure, restore marine ecosystems, and ensure a more secure and sustainable food future for generations to come. It's time to turn the tide and invest in the potential of microalgae to save our seas.

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This article is based on research published under:

DOI-LINK: 10.1038/s41598-018-33504-w, Alternate LINK

Title: Marine Microalgae Commercial Production Improves Sustainability Of Global Fisheries And Aquaculture

Subject: Multidisciplinary

Journal: Scientific Reports

Publisher: Springer Science and Business Media LLC

Authors: Colin M. Beal, Léda N. Gerber, Supis Thongrod, Wutiporn Phromkunthong, Viswanath Kiron, Joe Granados, Ian Archibald, Charles H. Greene, Mark E. Huntley

Published: 2018-10-10

Everything You Need To Know

What are the primary advantages of using marine microalgae as a fish feed ingredient compared to traditional fishmeal and fish oil?

Marine microalgae offer a balanced amino acid profile and are a natural source of n-3 HUFAs, making them an ideal replacement for fishmeal and fish oil. Commercial microalgae production can significantly reduce pressure on wild fish populations, promoting a more sustainable aquaculture industry. Large-scale algae production facilities can generate substantial revenue and net income, making them an attractive investment opportunity and microalgae production can lower greenhouse gas emissions compared to traditional fishmeal production, contributing to a healthier planet.

Why is there a growing need for alternatives to traditional fishmeal and fish oil in the aquaculture industry?

Traditional fishmeal and fish oil are produced by rendering a significant portion of the wild fish catch. As aquaculture expands, the demand for these ingredients is soaring. The challenge is finding replacements that can match the nutritional profile of fishmeal and fish oil, particularly n-3 highly unsaturated fatty acids (HUFAs). Plant-based alternatives often require supplementation and may contain anti-nutritional components.

How might marine microalgae transform the aquaculture industry and contribute to sustainability?

Commercial production of marine microalgae has the potential to revolutionize the aquaculture industry by offering a sustainable alternative to fishmeal and fish oil. This can lead to reduced pressure on wild fish populations, the restoration of marine ecosystems, and a more secure food future. A study adapting a model based on microalgae production results in Hawaii and applied it to Thailand showed promising results.

Why are n-3 highly unsaturated fatty acids (HUFAs) so important in fish feed, and how do marine microalgae address this need?

Marine microalgae have a balanced amino acid profile and are a natural source of n-3 HUFAs, crucial for optimal growth and health in fish. Terrestrial plants do not produce these in sufficient quantities, making marine microalgae a superior alternative for aquaculture feed.

Is the commercial production of marine microalgae economically viable for replacing fishmeal and fish oil?

Yes, studies, including one published in *Scientific Reports*, show that large-scale marine microalgae production facilities can generate substantial revenue and net income. This makes them an attractive investment opportunity, particularly as demand for sustainable fish feed alternatives increases. The economic viability, combined with environmental benefits, makes it a promising option.