As aquaculture booms, it’s consuming more fish than it produces

Aquaculture is one way to meet Asia’s growing demand for seafood, but using fish as feed could worsen the problem of declining fish stocks globally. What alternatives has the industry come up with to end this ‘fish-eat-fish’ world?

fish farm thailand
A fish farm in Thailand. Aquaculture is the fastest-growing source of protein today. Image: Shutterstock

From conveyor belt sushi to grilled fish stalls on the streets of Bangkok, the popularity of seafood as a source of protein is on the rise globally.

This is particularly so in Asia Pacific, which is predicted to account for 70 per cent of global seafood sales in the next 13 years, according to the Food and Agriculture Organization of the United Nations (FAO). Small-scale fisheries are also an important source of income and food in Asia, employing over 30 million people in coastal communities.

But although farmed seafood is touted as a more environmentally friendly source of protein—land-based livestock farming now facing fierce criticism and wild fish stocks in drastic decline—one issue remains a thorn in the side of farming seafood or aquaculture: fish feed.

Known in the industry as forage fish, species lower down in the food chain such as anchovies and sardines are turned into fishmeal and fed to farmed fish, and contributes to unstable fish populations. For instance, a study has found that aquaculture worsens the problem of falling fish populations in China.

Furthermore, feeding fish to fish is also inefficient. For every kilogram of salmon produced, for example, the farmer uses two kilograms of fishmeal over the course of the animal’s life.

Michael Philips, director of aquaculture science and fisheries at WorldFish, an international research organisation headquartered in Malaysia, explains: “A fair proportion of the fish production on the planet relies on fish feed. As we get intensive with our farming and try to increase productivity from the water to meet global demand for fish, demand for the fish that feed them grows even more.”

Alternative protein for fish feed

With the global spotlight on illegal, unregulated fishing and wild fish stocks at an all-time low, the aquaculture industry is looking to alternatives to forage fish.

One organisation doing this is the new Aquaculture Innovation Centre (AIC) at Temasek Polytechnic in Singapore, which is dedicating the first three years on research into optimal nutrition for fish farmed in intensive, high-tech environments. 

Centre director Dr Lee Chee Wee reveals that the centre is experimenting with different food pellets with reformulated nutrients that will be able to meet special requirements of urban fish farming and keep the animals healthy even under stressful conditions.

Due to Singapore’s limited land area, aquaculture farms are built vertically with tanks stacked on top of one another. Packed tightly, the marine creatures can suffer from heightened stress levels from being packed densely together. 

“The best feed is still protein, which comes from fish meat. But catching fish to feed fish doesn’t make sense, and there’s no longer any fish for you to catch anyway,” says Lee.

According to him, the answer to sustainable aquaculture lies in cities, where large quantities of high quality waste, such as food waste, are produced. As part of the centre’s research, he is investigating how waste products can be processed into fish feed. 

“Every city has their own urban waste and this waste is usually disposed with at a cost, but we can actually turn that into a high-quality valuable product for the fish. With urban fish farming, there’s huge potential to have a very small environmental footprint,” he says. 

Fish-free opportunities for business

Companies are jumping on board the business of alternative fish feed to address the depletion of wild fish stocks and deliver health benefits to seafood consumers.

One example is a joint venture by DSM and German chemicals company Evonik. Veramaris cultivates marine algae rich in omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).

Using technology developed by US space agency NASA in the 1960s, Veramaris produces an omega-3 algal oil that Karim Kurmlay, chief executive officer, says is richer in EPA and DHA than alternatives and more than twice as rich as feed grade fish oils, leading to more benefits to both fish and consumer health.

“This innovation will help alleviate pressure on over-fished wild fisheries, enable the salmon industry to become a net producer of fish, help improve marine biodiversity and allow the salmon industry to raise the omega-3 levels in the fillet sustainably,” says David Nickell, vice president of sustainability, animal nutrition and health at DSM, adding that the Veramaris facility can produce the amount of algal oil equivalent to 1.2 million tonnes of wild-caught forage fish in a year.

Farmers include fish oils in feed because fish must get sufficient EPA and DHA omega-3 fatty acids to stay healthy, while the omega-3 levels in salmon have declined to less than half of what it used to be over the last decade, says Oyvind Ihle, Veramaris’ global marketing and communications director. The main reason being that forage fisheries were not able to keep up with demand as well as cost considerations.

“Fish farming relying on fish oil as a source of omega-3 cannot grow much further as there is simply not enough fish in the ocean. On the other hand, if fish farmers could get alternative sources of EPA and DHA they could both relieve some pressure off [natural fish stocks] and get on a more sustainable growth path for their business,” Nickell adds.

Catching fish to feed fish doesn’t make sense, and there’s no longer any fish for you to catch anyway.

Dr Lee Chee Wee, director, Aquaculture Innovation Centre, Temasek Polytechnic

Around the world, business have come up with other creative ways to produce fish feed that do not further exploit the marine environment.

In Africa, cassava waste is being processed to feed fish in farms, while start-ups in Asia are investing in cultivating black soldier fly larvae and single cell proteins derived from yeast and bacteria to replace fishmeal. There are many more ways to use ingredients to feed fish that are not competing in any way with human food, said WorldFish’s Philips.

“The world is eating and likely needs to eat more seafood. But oceans have limited capacity to supply the seafood that the human population requires,” he adds.

Experts predict that aquaculture will have to more than double production by 2050 to meet global demand, and that within the next two years, the amount of fish farmed will exceed that caught in the wild.

“This is a part of the food system that has changed very quickly over a short period of time, from very wild-based to being a production system split between the waters and farming,” says Philips.

The impact of fisheries can be managed by using alternative feedstock so that rivers and oceans can be allowed to recover, even as they are harvested sustainably for food, he adds.

Like this content? Join our growing community.

Your support helps to strengthen independent journalism, which is critically needed to guide business and policy development for positive impact. Unlock unlimited access to our content and members-only perks.

Most popular

Featured Events

Publish your event
leaf background pattern

Transforming Innovation for Sustainability Join the Ecosystem →