As the pressure on the ocean’s resources intensifies, aquafeed companies—big and small—are searching to find new ways to provide the protein fish need to grow. Many of these alternatives are promising, but can they ever replace fishmeal?

Fish farms are the fastest-growing food production method in the world and the fish feed industry, which relies on small fish around the world to feed those farms, has come under increasing pressure to find alternative nutrition sources. A recent study in the science journal Nature predicted that the demand for fish feed “will eventually surpass ecological supply of forage fish” and called for “alternative feed sources.”

Wing Yin Mo, an environmental scientist, is trying to offer just that. He has developed a fish feed made from food waste—including expired items from grocery stores and discarded food and scraps from restaurants.

“We have lots of food waste in Hong Kong and China,” says Mo, who is completing his postdoctoral studies at Hong Kong Education University. He says 3,600 tons of food waste is sent to landfills every day in Hong Kong. “I am trying to recover those resources as much as possible.”

Mo’s alternative feed aims to address two problems at once—the need for fishmeal and too much trash. Nearly 40 percent of Hong Kong’s municipal garbage is food waste. Using some of that for feed could both reduce the amount of garbage and relieve pressure on the South China Sea’s wild fish stocks that are currently caught for fishmeal.

For small-scale fish farmers in particular, Mo says his product is an environmentally and financially sustainable choice, since his formula uses about half the amount of fishmeal as commercial feed, at about half the price. Typically, fish feed is the largest cost for farmers, so cheaper feeds can have a big effect on bottom lines for local fish farmers.

But Mo’s research is only in its preliminary stages. He acknowledges that the formula still needs improving, and that more collaboration and support will be required to make his product scalable.

Scientist working on food waste as alternative protein source
Win Ying Mo has developed a pilot project in Hong Kong that uses food waste as an alternative protein source for fishmeal. Photo by Annie Rueter

Global incentive to develop alternatives

As more and more of the world’s people rely on farmed fish for meals, innovators around the world are working to find sustainable alternatives to produce the feed needed to sustain farms long-term. The World Wildlife Fund has been pressuring the fishmeal industry to develop alternative sources of protein for fish feed.

“It’s time for the commercialization of these sustainable alternatives, so we can achieve sustainable and affordable food in a way that is ethical, economical and environmentally respectful,” said Marcela Navarro, co-founder and CEO of Project X, an independent company first launched as a project by WWF.

According to a recent report commissioned by Project X, the global feed industry is one of the 10 industry sectors particularly harmful to biodiversity and climate due to its high levels of greenhouse emissions.

Overhead view of fish farm
WWF affiliate Project X is partnering with fish feed giant Skretting to find ways to make more sustainable feeds. Photo by Project X

To respond, Navarro and her team launched a challenge earlier this year to help identify innovations that will enable the fishmeal and fish feed industry to shift toward more sustainable alternatives. Norwegian company Skretting, which is the largest producer of salmon feed in the world, partnered with Project X to create the FEED-X challenge.

Their aim is to shift 10 percent of the world’s feed production to alternative ingredients by 2025. FEED-X invites and incentivizes innovators to develop more sustainable fishmeal alternatives and technology for producing feed for shrimp and salmon—two of the world’s most popular seafood products—on a marketable scale.

“To feed the 9.7 billion people on this planet [by 2050],” says Navarro, “we need to look into non-traditional innovations and collaboration models to achieve the results we need, at the pace the planet needs it.”

Novel ingredients on the rise

The push for industry to replace forage fish with alternative ingredients isn’t new. For the past 30 years, the percent of farmed fish eating fishmeal has declined as the $69 billion aquafeed industry increasingly turned to novel ingredients.

Skretting, for example, developed aquafeed for salmon without using fishmeal or fish oil more than three years ago. The feed’s source of omega-3 fatty acids, typically found in forage fish like mackerel and anchovies, comes from marine algal oil. The acids are essential for brain development and human health.

iAlgal oil

Extracted directly from algae, algal oil is is seen as a good alternative to fishmeal because it’s packed with healthy oils. Algal oil provides a natural source of omega-3 fatty acids DHA and EPA, which are important to keep farmed fish healthy. In the past, fish feeds have traditionally relied on fish oil as the main source of these fatty acids. But the finite amount of fish oil available means that the industry has turned to algal oil as a viable alternative.

The company behind Skretting’s algal oil project, Veramaris, recently opened a $200 million facility in Nebraska. Now, major European retailers, including UK-based Tesco and French supermarket chain Match, are selling salmon raised on algal oil-based feeds, and are encouraging salmon suppliers to use alternative ingredients.

Another possible protein substitute are soybeans. Most soybeans go toward animal feed, but they are also the most commonly used vegetable protein in fish feed. However, relying on soy to replace forage fish poses challenges of its own. A recent study by Rainforest Foundation Norway found the three main soy suppliers to the Norwegian farmed salmon industry “are linked to illegal deforestation, land conflict, soy on Indigenous territories, illegal pesticides and slave-like labor conditions, through their supply chains.”

Insects as alternative to fishmeal
Insects are an increasingly popular alternative to fishmeal. Photo by Enterra Feed Corporation

Since most farmed fish are carnivorous, one alternative to forage fish in fishmeal is another source of animal protein—insects.

Taplow Feeds, based in Canada, has been using bugs to supplement fishmeal in its pet and aquafeeds for more than a decade. The company sources the grubs from Enterra Feed Corporation, also based in Canada, who grow black fly soldier larvae on food waste. The insects then get processed into grubs, protein meal or oil suitable for fish diets.

“If we can take what is currently a waste stream and turn it into food, it’s actually not a bad idea in my view,” says Brad Hicks, vice president of Taplow.

Insect meal has high-quality protein, vitamins and amino acids and produces minimal greenhouse gas emissions. They may have potential, but it’s not a magic bullet. Even Hicks acknowledges the relatively-new industry cannot supply enough quantity to replace fishmeal, and there are limits on how much insect meal can be incorporated into feeds.

“At this stage of industry development, it’s really not feasible [to completely replace fishmeal with insect meal],” Hicks says. “Insect meal is not going to replace fishmeal tomorrow or the day after. We are talking years and years.”

But finding substitutes for forage fish seems inevitable. Even the leading fishmeal and fish oil industry group acknowledges the need for alternative ingredients even if it maintains that fishmeal and fish oil will forever be a key part of the aquafeed industry.

“The way that we see the rise of the novel ingredients is that they’re very much needed to help provide that additional volume for feed for agriculture and aquaculture,” says Neil Auchterlonie, technical director of IFFO–The Marine Ingredients Organization. But “fishmeal and fish oil are always going to be part of [the feed] because they are [a] very effective and practical means of supplying that nutrition.”

Over the past three decades, the industry has significantly decreased its “Fish In: Fish Out” ratios, a measurement used to compare the amount of wild fish it takes to produce an equivalent weight of farmed fish.

According to the IFFO’s most recent figures, the ratio is now better than 1:1—in other words, it takes less than a pound of wild fish to produce a pound of farmed salmon or trout. So today, according to industry numbers, there is a net gain in protein, which is a huge improvement over the ratio in 2000, when it took 2.5 pounds of wild fish to produce one pound of farmed salmon.

Fisherman supplements with an alternative feed produced using food waste
Fisherman Lueng Kam Wah supplements with an alternative feed produced using food waste but still relies heavily upon wild fish to feed his farm. Photo by Yuxian Wang

What consumers can do

Globally, there are more than 30 different aquaculture certifications, standards, and schemes intended to guide consumers’ choices when purchasing seafood.

Criteria vary, and some of them evaluate the source of feed for farmed fish as part of the assessment.

“We look at both the source of the fishmeal and how efficiently it is processed into fish protein on the other end,” said Alasdair Lindop, the science lead on aquaculture at Ocean Wise in Vancouver. “[We] make sure [the fishmeal] is from a wild fishery that’s already been assessed as sustainable. And then we are looking at the energy transfer—we want it to be as close to a ratio of one to one, so one kilo of fish in, to one kilo of fish out,” he said.

Lindop says that many fish consumers do not know that most farmed fish need fishmeal to grow, and he urges shoppers to choose sustainably-sourced seafood.

“From a layman’s point of view, I don’t think fishmeal is something that people understand well,” he said. “But I think that’s across all kinds of agriculture. I don’t think people think too much about what you’re feeding [cows] or chickens.”

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