Turning yeast into sustainable fish food

Genetically modified yeast can replace wild-caught fish in farmed salmon diets, says Scott Nichols, director of DuPont’s aquaculture joint venture.

As a child living in Hawaii, Scott Nichols woke early. By 6 a.m., the 5-year-old boy had usually reeled in his first catch from a pre-dawn fishing expedition with his dad. The first week that he carried his bounty—a whole fish—into the family kitchen for breakfast, his father gave him an impromptu lesson in gutting and cleaning fish. And a love affair with seafood was born.

How ingenuity will feed the world.
Scott Nichols

Much later in life, Scott Nichols found himself in the lucky position of being able to turn that love for fish into a business venture. As a biochemist with a doctorate from UCLA who also studied business at the Wharton’s Advanced Management Program at the University of Pennsylvania, Nichols was in charge of DuPont’s business development. It was 2006, and the company had created an innovation around bio-based omega-3 fatty acids: DuPont’s genetically modified yeast could substitute for fish oils and preserve the omega-3 fatty acids. But Nichols knew it was a breakthrough in another area as well. “In the blink of an eye, I realized that we could solve a big problem with salmon aquaculture,” says Nichols, who now directs Verlasso, a joint venture between DuPont and AquaChile—an aquaculture operation based in Patagonia—that was formalized in 2009. Before the partnership, DuPont had been involved in supplying the aquaculture industry but had no experience in aquaculture production.

There seems to be precious little international enthusiasm to talk about how to reduce pressure on fisheries, but it is surely needed.”
—Scott Nichols

Reducing reliance on wild-caught fish for salmon feed

Fish oil produced from wild-caught fish supplies critical nutrients that farmed salmon need to grow, but these wild-caught fish are harvested unsustainably. By 2006, salmon aquaculture was consuming some 80 percent of the world’s fish oil and still growing at a rate of 8 to 10 percent per year. Oily fish like anchovies, menhaden and mackerel provide the main source of fish oils, and their harvests are threatened as their populations deplete.

“We are looking at a future where there would be no more fish oil to be had,” says Nichols. “I thought, if we are able to provide the omega-3 to the salmon using DuPont’s yeast that is rich in omega-3s, and use far fewer wild-caught feeder fish for the diet, it would do a lot of good for the oceans while sustainably supplying farmed salmon with omega-3s.”

Verlasso’s method of salmon aquaculture reduces reliance on wild-caught fish by 75 percent. Four pounds of wild-caught feeder fish are typically needed to produce the fish oil to make one pound of salmon. Verlasso, on the other hand, relies on just one pound of wild-caught fish to produce one pound of salmon. “We have lowered the fish in/fish out ratio. One in and one out,” says Nichols.

Verlasso has also identified ways to get down to about three-quarters of a pound of wild-caught fish used per one pound of fish produced, and Nichols believes the company will be able to achieve that over time. Although the joint venture’s current focus is on raising Atlantic salmon, the feed could certainly be useful for other salmon species, says Nichols, such as steelhead or coho.

“Everyone recognizes we can’t continue to harvest forage fish to feed oil to salmon,” he says. “Some people ask, How do we use these [forage] fish with most efficiency? The proper question is, How do we use them not at all? They need to be food sources themselves.”

According to Verlasso, the company saved more than 6 million pounds of feeder fish in 2013 by significantly reducing the amount of fish oil it uses in raising salmon. However, Nichols says providing omega-3s to the fish through the yeast is more expensive than using fish oil.

“The company formulates the fish diets based on optimal performance rather than least cost, and a number of the ingredients in our feed are more expensive than those used in traditional salmon aquaculture,” he says. The fish grow in the southern Pacific Ocean off of Chile, reaching harvest size in about two years in pens with fewer than four salmon per ton of water, or about 50 percent more room per fish than the industry standard.

The case for sustainable fish farming

While fish farming is Nichols’ business, he says he often thinks of the pressing problems with world agriculture and how enough food will be produced to feed the expanding global population in decades to come. “We’ve got to find ways to do more with less. How do we develop agriculture practices that operate in harmony with the environment and allow us greater intensity? There is a lot of ocean out there that we could use for raising plants and animals,” Nichols says. “We need to find ways to use the oceans and use them properly to raise more food. I heard a great quote from former NOAA [National Oceanic and Atmospheric Association] administrator Jane Lubchenco: ‘It’s OK to use the oceans, and not OK to use them up.’”

Nichols remains concerned about the way oceans currently are used. He points to a 2012 study from the Food and Agriculture Organization of the United Nations (FAO) that reported 87 percent of the world’s fisheries were harvested at or above their sustainable limits. In 2014, that number rose to 91 percent.

“We are not going in the right direction,” says Nichols. “I hope it is axiomatic to say that it is indefensible to harvest a fishery above its sustainable level. A thornier question is how we should respond to roughly half of the world’s fisheries being harvested at the upper limits of sustainability. Operating at the very edge leaves little or no room to accommodate things unforeseen. . . . There seems to be precious little international enthusiasm to talk about how to reduce pressure on fisheries, but it is surely needed.”

If people are going to continue to eat fish, says Nichols, they must be farmed and they must be raised sustainably. “All agricultural production, whether on land or in water, has environmental effects. The key consideration is that we manage those effects so that our practices today do not impinge on our ability to practice in the future,” he says.

Based on Verlasso’s continuous improvement in its award-winning aquaculture practices, the company’s ocean-raised farmed Atlantic salmon was the first to receive the “good alternative” ranking in 2013 from the Monterey Bay Aquarium’s Seafood Watch Program. Looking ahead, Nichols says the next phase of work is a bit unglamorous but important: Verlasso is re-examining its farming practices to see how they can raise fish more efficiently and to be more healthful without increasing their costs. They hope to achieve this while searching for ways to reduce the use of wild-caught fish because, he says, “it is imperative we diminish our pressure on wild fisheries.”

Lisa Palmer

Lisa Palmer is a freelance journalist and writer based in Maryland. She reports on food, the environment and sustainable business for publications such as Slate, Scientific American, Nature, Yale e360, and The Guardian. She is a fellow for socio-environmental understanding at the National Socio-Environmental Synthesis Center (www.sesync.org) in Annapolis, Md.

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