September 24, 2015
Water laps gently against the canoe as Felix paddles across Lake Volta. Once he reaches the floating cages, he scoops some pellets that look like typical fish food and sprinkles them over the water. Hungry tilapias dart to the top. They gobble the beads in such a frenzy the surface of the water erupts like a fountain.
Felix is feeding fish as part of a research study in Ghana. The tilapia fingerlings in this one-month growth trial have been divided into four groups. Felix feeds one group by tossing them a cupful of typical tilapia food enriched with vitamins, minerals, wheat, poultry by-products and fishmeal. The other three groups feast on the same feed, but instead of fishmeal, they get varying amounts of insect meal. Like fish, insects can be converted into a high-protein, high-energy feed.
Fingerling Food in Ghana
The trial was part of PROteINSECT, a project headed by the Food and Environment Research Agency in the United Kingdom, started in February 2013. Emilie Devic, a scientist at the Institute of Aquaculture, University of Stirling, UK, ran the trial. She’s studying black soldier fly larvae meal to determine if it’s a viable substitute for fishmeal.
“I spent sixteen months in Ghana setting up the insect farm and producing enough insects for this trial. That was a big challenge. There was nothing like this when I started,” explains Devic. “Dried black soldier fly larvae were ground into meal and incorporated into a commercial mixture for tilapia fingerlings.”
Once the insect farm was generating enough material, her study got underway. “Fish were fed six times a day, manually, by experienced feeders,” says Devic. To understand how well the fish developed with the various feeds, Devic and her team netted the tilapias and slid them into buckets. As the fingerlings flopped, Devic’s group counted, weighed, examined, and recorded them.
Although her results have not been published yet, she is enthusiastic about the project. “They were aggressive feeders,” says Devic. “They have grown well and shown a good response. The preliminary results will encourage others!”
The insect farm is still operating in Ghana, but Devic has moved on to the next phase of the project, which will be in the United Kingdom. “We’re starting a trial on Atlantic salmon,” says Devic. “We’re replacing different levels of fishmeal, but this time we will go further and also study digestibility.” The project is important, she says, because it looks at insect meal as an alternative to fishmeal in poultry, pigs, and fish production systems.
The Overfished Meal
Americans savor flaky salmon and plump shrimp—but how does our appetite for these fish affect the oceans? Atlantic salmon is an endangered species, so commercial fishing is prohibited. As a result, only a small fraction of the salmon we consume is wild-caught salmon from the Pacific. About two thirds of the salmon we devour comes from fish farms.
Fish-farming, also known as aquaculture, is a booming business. In 1980, only nine percent of the fish we ate was farmed. Today, nearly half of the world’s seafood is grown and raised through aquaculture, but these farms are not as efficient as they appear.
Fish raised on farms get fat either on a diet of soy, or on a diet of fishmeal and fish oil, which are made from other ocean fish. It takes three pounds of fishmeal to raise one pound of salmon. With the world’s population expected to expand by over two billion in 2050, the need for fish feed is predicted to surge. The Food and Agriculture Organization of the United Nations projects that by 2030, aquaculture may face a serious challenge—fishmeal could be depleted. A substitute is urgently needed. While soy is outpacing fishmeal in aquaculture and may represent one option, another promising alternative is insect meal.
Larvae Flour Power
“Black soldier fly larvae meal is a really fantastic substitute for fishmeal,” says Cheryl Preyer of EnviroFlight, an Ohio company that produces the meal. “It’s got the right amino acid profile and the right protein levels. It’s highly digestible.”
EnviroFlight, founded by Glen Courtright, is not the only player developing and producing insect feed. Other companies have sprung up in Canada, France, Spain, the Netherlands, and South Africa. “Many people are open to the idea,” says Preyer. “It’s gaining a lot of traction.”
In polluted areas, tiny fish may contain mercury, PCBs, or dioxins. When farmed fish gulp down contaminated fishmeal, they ingest these toxins—but that’s not a problem with insect meal. “We have much more control of what our larvae are exposed to,” explains Preyer. “We’re feeding them pre-consumer food waste that would be approved by the Association of American Feed Control Officials.”
At EnviroFlight, wriggling larvae gorge on gruel. They’re lightly toasted, sifted and pressed. “When we crush the larvae our oil is not high in omega-3 fatty acids, like fish. We’re looking for ways for them to uptake more.” After pressing to extract fat, the protein-rich substance is then ground to make a fine meal. “It looks like brown flour,” says Preyer. “It smells nutty.” Currently, EnviroFlight sells larvae meal as feed for pangolins, reptiles, ornamental fish and exotic birds.
Although insect meal holds a lot of promise, hurdles remain. It’s costly because production is so new that systems and technology aren’t in place to produce it in great quantities. “Regulatory approval is the biggest barrier we have at the moment,” says Preyer.
In the United States, the laws are unclear on farming and selling insects as feed. But one thing is crystal clear—if we don’t find a suitable substitute for fishmeal, we could face a shortage. “If we’re going to feed all the people that we’re going to have on this planet, fish is a fantastic option,” says Preyer, “but we have to be able to feed the fish.”
Images by Alexander Winch (illustration), and Mike Milli (photograph).
This work by Linda Zajac and the Johns Hopkins Center for a Livable Future is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
Based on work at www.livablefutureblog.com. Images in this post are included in the Creative Commons license.