Frankenfish: Is GM Salmon a Vital Part of Our Future?

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Salmon at a fish market.

As I write in this week's TIME cover story, aquaculture — fish farming — is an increasingly essential part of our global food system. Already about half of our seafood starts on an aquatic farm, and as seafood demand continues to rise and the wild ocean catch plateaus, you can be certain that the emphasis on aquaculture will continue to grow.

For much of the world, that's a good thing. Seafood tends to be healthier than land-raised meat, and fish farming on the whole is a more efficient way to produce protein than raising traditional farm animals. (Efficiency in this case means turning inputs — fish feed — into outputs, fillets on your table.) If aquaculture can deliver inexpensive protein to the masses, it could go a long way toward meeting the increasing demand for food globally, expected to double by midcentury. "We need to shift from collecting and harvesting fish in the wild to a culture bred around seafood production," says Yonathan Zohar, the director of the Center of Marine Biotechnology at the University of Maryland. "[Fish farming] needs to be sustainable and it needs to be economically feasible."

But there's a major problem with the expansion of aquaculture as it's practiced today: fish feed. The most popular commercial species — think salmon — tend to be carnivores high on the food chain, so they need to be fed a lot of smaller fish in order to grow. If we end up taking more fish mass out of the ocean for feed than we produce via farming, well, that's not very sustainable. One way around that obstacle is to pick more farmable species, like barramundi and tilapia, which produce more protein than they need as feed. But that doesn't satisfy the consumer demand for salmon or tuna or cod. "With aquaculture it's a bit like we're trying to fit a square peg into a round hole," says Paul Greenberg, the author of Four Fish, one of the best books on global seafood. "We can try to change the hole with different species, or we can try to make the peg fit that hole."

Trying to make a better peg — that's a pretty good description of what a small Massachusetts-based biotech company called AquaBounty is trying to do with Atlantic salmon. AquaBounty's AquAdvantage salmon contains a gene from the chinook salmon, a larger cousin that cruises colder waters in the north. That gene keeps a vital growth hormone activated rather than shutting it down after a certain point, enabling the AquAdvantage salmon to grow more quickly — up to twice as fast as a conventional Atlantic salmon, according to AquaBounty. Such speed has obvious economic benefits for producers, enough that it could possibly make farming of salmon much more economically viable in the U.S. (Nearly all of the farmed salmon consumed in the U.S. comes from abroad, in part because costs tend to be lower.) "We're loading up 747s from Chile full of farmed salmon and flying them to North America with a huge carbon footprint," says Ronald Stotish, AquaBounty's CEO. "With this we could grow salmon in land-based systems in the U.S., raising fresh seafood close to where it's needed."

The Food and Drug Administration convened a panel of experts last fall to review the genetically modified (GM) salmon, and they were mostly satisfied with AquaBounty's proposals. Many environmental groups, however, haven't been so happy with what they've come to term the Frankenfish — which would be the first GM animal to hit the market if approved. (A spokesperson for the FDA said that the agency was still reviewing the AquAdvantage salmon, and that there was no timetable for a decision.) "You can have unknown outcomes from genetically modifying a species," says Zach Corrigan, the fish-program director for Food & Water Watch, an NGO opposed to GM technology. "We don't think they've looked carefully enough at those possible effects."

Skeptics worry the GM salmon might provoke an allergic reaction in some consumers, but the real fear has more to do with what kind of damage the modified fish might do if it escaped into the wild. Conventional farmed salmon frequently break free of the sea nets they're raised in, and they can mix with wild populations of fish. That's not good for their wild cousins: a farmed fish, like a domesticated pig, is bred for a life in captivity, not in the open oceans, where it needs a different suite of survival traits. Not only can escaped farmed fish spread disease — farmed salmon, for instance, can transmit the deadly parasite sea lice to wild fish — they can actually degrade the gene pool through interbreeding. So it's not hard to see why many environmentalists worry about the havoc a GM salmon might do if it got loose and started mating. Just watch Jurassic Park.

For its part, AquaBounty says it will ensure that its modified fish never taste freedom. According to the company's proposal, the GM salmon would be raised only in closed containment systems — inland or indoor tanks that are essentially Alcatraz for fish — not the open-ocean nets that are common for conventionally farmed species. AquaBounty would ensure that nearly all of the fish are sterile by ensuring they carry only female genes. And even if the fish did manage to escape into the wild, many scientists believe they wouldn't have innate skills to compete for mates — and therefore wouldn't do much damage to the wild gene pools. "If they have no mating advantage, than it seems like natural selection would purge them quickly," says William Muir, a population geneticist at Purdue University who has developed models used for evaluating the risks posed by modified fish. "I have no concerns about this fish in this environment."

Not every scientist is so sanguine, and the reality is that there's no real way of knowing what impact GM salmon might have on the wild environment unless you let a bunch loose in the ocean — and nobody plans for that to happen. Skeptics also argue that the GM salmon aren't worth the trouble. Fish farmers have managed to create increasingly efficient salmon the conventional way — breeding them — reducing the advantage that AquaBounty's nearly two-decade-old technology might offer. And salmon farmers, who have long fought the public perception that their industry is a dirty one, may not be eager to court public controversy by raising a transgenic fish. (AquaBounty wants to sell the eggs to producers, not raise the fish themselves, meaning that the farmers would take the heat from unhappy consumers.) "I can't see an [aquaculture company] that would go out and hurt the market by taking on that contentious issue," says Nell Halse, a spokesperson for Cooke Aquaculture, a major fish-farming company in Canada and the U.S.

Even if AquaBounty's technology doesn't take off in the U.S., it may find success in China or other parts of the developing world where wealth and seafood consumption is rising, where the government is more comfortable with GM foods and, significantly, where regulation might be more lax. There are also other genetically modified animals in the development pipeline, from a transgenic trout that can pack on 15% to 20% more muscle than a conventional trout to a GM pig that produces less-polluting manure. Genetic modification — especially in animals — is a new technology and a potentially very scary one, but if scientists can engineer species to use feed more efficiently and emit less waste, they could help fish farming become more environmentally friendly, not less. "With the right safety measures, I'm willing to embrace the technology as an incremental step toward sustainability," says Eric Hallerman, a fisheries scientist at Virginia Tech who has studied the GM salmon. "You have to consider the larger picture." The Frankenfish isn't without its risks — but neither is a crowded and hungry future.