Photograph by Brian J. Skerry, Nat Geo Image Collection
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Many farmed fish like these cobia eat other fish, which makes them less sustainable than vegetarian fish.
Photograph by Brian J. Skerry, Nat Geo Image Collection

Will a Reward Entice Inventors to Tackle Fish-Free Fish Food?

There’s a contest going on, and the prize is $100,000. Anyone can play! Anyone, that is, with the ability to make 100,000 metric tons of fish feed. Vegetarian fish feed.

One of the biggest challenges facing aquaculture is how to feed fish without having to raid the oceans for the small fish that go into feeding those farmed fish. Wild fish such as anchovies and menhaden produce two of the components of all fish feed, protein and oil. But harvesting them from the ocean only adds pressure to depleting global fish stocks.

The purpose of the F3 [Fish-Free Feed] Challenge, according to University of Arizona professor Kevin Fitzsimmons, who started it, is to bring attention to this critical issue. “We have to make the limited amount of fish meal and fish oil we’ve got go a whole lot further,” he says. But right now vegetarian feed is a “niche market.” He’s hoping that the contest will get feed companies, fish farmers, chefs, and consumers to “support the equivalent of grass-fed fish.”

The $100,000 comes from a donor who would prefer to remain anonymous, but there’s also a crowdfunding element for anyone who wants to sweeten the pot. To win the challenge, you have to produce those 100,000 metric tons (that’s 220 million pounds, a tall order) by September 2017.

It’s important to add that there’s already fish-free feed on the market. You can even buy vegetarian trout raised by a San Francisco company called TwoXSea. And, if you’re an American taxpayer, you made it possible, since the formula for the feed was developed by USDA fish nutritionist Rick Barrows in the Fish Technology Center in Bozeman, Montana.

So why do we need a contest for what already exists? According to Barrows, it comes down to affordability. “Vegetarian feed is double the price, maybe more,” he says.

According to Barrows, the challenge of fish-free feed lies in its protein and fat components. Wild fish destined for feed are processed into fish meal (the protein) and fish oil (the fat). To replace fish in the diet, you have to find substitutes for both those elements.

Feed formulators have gotten pretty good at the protein part. They’ve figured out how to process soybeans, which, straight off the plant, don’t make good fish protein because they contain compounds that are bad for fish. And not just for fish. Some of those same compounds—particularly indigestible starches called oligosaccharides—are bad for other animals too.

“Remember 20 years ago when dogs used to fart all the time?” Barrows asked. “That was oligosaccharides.” Soy protein concentrate, a distillate that contains the protein and not much else, is much more digestible by fish and dogs alike. Meanwhile, plant breeders are tackling the problem from the other end by trying to develop a soy plant that has less of what animals can’t digest.

Soy isn’t the only protein choice. “There are going to be a lot of regional ingredients,” says Barrows. “There’s a company in California using pistachio and almonds that can’t be certified—too big, too small, too green, too pale.” Barley is another choice, as is the spent grain from brewers and distillers.

Fat is the bigger challenge because fish contain healthful fats, long-chain omega-3s that they get from food and that are essentially found only in marine sources. Terrestrial plants have different kinds of omega-3 fats—short-chain—but only trace amounts of the long-chain kind. Right now, virtually the only vegetarian choice is algae. And algae is expensive. “Growing something inside, in tanks, is more expensive than outside, in a field,” say Barrows.

Barrows is confident that technology will gradually bring down the cost of vegetarian feed and hopes the contest will shine a light on the problem. But it’ll be a while before fish-free feed is completely cost competitive, and consumers, meanwhile, need to be willing to pay more to eat a fish that eats it. The biggest hurdle F3 contestants will face, Barrows says, is finding enough farmers to buy 100,000 tons of the feed; chefs and consumers need to create the demand.

Michael Tlusty is director of ocean sustainability science at the New England Aquarium, which will be teaming with the Monterey Bay Aquarium to judge the contest. “It’s a way to spur innovation,” he says of the $100,000 prize, but he emphasizes that vegetarian feed isn’t the only way to raise fish sustainably. “There are some really good sources of fish meal,” he says, pointing to processing waste and well-managed forage fisheries. “But we also need more tools. We need to get people OK with the idea of alternate feed components.”

Here’s hoping $100,000 helps.

Tamar Haspel is a food and science journalist. She can be reached on Twitter @TamarHaspel.