U.S. Consumers Might Get Their First Taste of Transgenic Salmon This Year

Photo: AquaBounty Technologies After 12 months, an AquAdvantage salmon [above, rear] is much larger than its nontransgenic sibling [front].

Inside a row of nondescript buildings in the small town of Albany, in northeast Indiana-approximately 1,000 kilometers from the nearest coast-Atlantic salmon are sloshing around in fiberglass tanks.

Only in the past five years has it become possible to raise thousands of healthy fish so far from the shoreline without contaminating millions of gallons of fresh water. A technology called recirculating aquaculture systems (RAS) now allows indoor aquaculture farms to recycle up to 99 percent of the water they use. And the newest generation of these systems will help one biotech company bring its unusual fish to U.S. customers for the first time this year.

For AquaBounty Technologies, which owns and operates the Indiana facility, this technology couldn't have come at a better time. The company has for decades tried to introduce a transgenic salmon it sells under the brand name AquAdvantage to the U.S. market. In this quest, AquaBounty has lost between US $100 million and $115 million (so far).

In the final months of 2020, the company will harvest its first salmon raised in the United States and intended for sale there. Thanks to modifications that involved splicing genetic material into its salmon from two other species of fish, these salmon grow twice as fast and need 25 percent less food to reach the same weight as salmon raised on other fish farms.

Since AquAdvantage salmon are genetically modified, the company has taken special precautions to reduce the odds that these fish could reproduce in the wild. Raising all the salmon indoors, far away from wild populations, is key to that equation. And that strategy wouldn't be possible without modern recirculating systems.

But it's not yet clear whether U.S. consumers will buy AquaBounty's salmon, or even if stores will sell it. Already Costco, Target, Trader Joe's, Walmart, Whole Foods, and roughly 80 other North American grocery store chains have said they don't plan to carry it. As of December, AquaBounty was unable to name any restaurants or stores where customers would be able to buy its salmon.

A 2018 report by Diamond Equity Research, paid for by AquaBounty, estimated potential annual sales of $10 million in the United States. Meanwhile, sales in Canada-where AquAdvantage salmon has been sold since 2017-brought in just $140,371 in the first nine months of 2019.

In late October, the biotech firm Intrexon Corp., which held 38.1 percent of AquaBounty's shares, sold its entire stake to Virginia-based TS AquaCulture for $21.6 million. Both firms are owned by billionaire biotech investor Randal Kirk.

Eric Hallerman, a fisheries scientist at Virginia Tech who served on the U.S. Food and Drug Administration panel that reviewed AquAdvantage salmon, thinks it deserves a place on the table. "People want to eat more meat. We have to do it efficiently," Hallerman says. "So, I think this has to be part of that."

Photo: AquaBounty Technologies At AquaBounty's Indiana facility, a recirculating system cleans and recycles water from tanks.

The first generation of recirculating systems, which rolled out in the 1980s and 1990s, largely failed. The filters involved couldn't remove enough waste to maintain water quality at the indoor aquaculture farms that installed them. "Few [of these systems], if any, are still around," says Brian Vinci, director of the Freshwater Institute, a program sponsored by a nonprofit called the Conservation Fund that has developed recirculation technology. "The ones that [still exist] grow tilapia-a very hardy species that's able to handle 'just okay' water quality."

Since then, scientists and engineers at the Freshwater Institute, Cornell University's College of Agriculture and Life Sciences, and companies including Veolia have improved the technology for the next generation of systems-such as the one installed at AquaBounty's Indiana facility.

These systems use a series of mechanical and biological filters to remove solid waste, ammonia, and carbon dioxide-all produced by the fish-from the water used on the farm. Sensors monitor temperature, pH, and water levels in every tank and track the oxygen content of the water, which must be replenished before it cycles back through. Alarms alert staff to potential problems.

Like all salmon, AquAdvantage fish begin life as fertilized eggs. In AquaBounty's case, salmon start out at a hatchery on Prince Edward Island, in Canada, where the company keeps a small breeding stock. Technicians there gently massage female fish to extract eggs and prompt males to expel milt, or semen, which the staff mix together to produce fertilized eggs. Aside from the fish used in breeding, all the other salmon the company produces are sterile females, which cannot reproduce with one another or with wild salmon.

When these eggs become "eyed eggs"-so named because two little black eyes suddenly become visible inside each gelatinous orange blob-the eggs are considered stable enough to transport. At this point, they're moved from the Prince Edward hatchery to AquaBounty's Indiana farm, where the company had about 150,000 eyed eggs on site in November.

When the eyed eggs arrive, they're put onto large trays that hold as many as 10,000 at a time. Then they're placed into one of two incubation units until they hatch (typically within two weeks) and absorb their yolk sac-at which point the fry are said to be "buttoned up."

The buttoned-up fry then slide into one of 12 small tanks in a nursery, where they begin eating commercial feed (the same kind used on other fish farms) until they weigh about 5 grams. Then they're transferred into one of 24 tanks-still in the nursery-until they hit 40 to 50 grams.

At that point, the fish are moved from the nursery to a set of "pre-grow out" tanks, which can hold up to 20,000 fish at a time. Once they reach 300 grams, they're switched over to a set of six tanks where they grow to about 4.5 kilograms.

Right before harvest, the fish must spend about six days being purged in specially-designed tanks that pump in fresh water. Here the fish are rinsed of any compounds that may have built up in the recirculation system and could spoil the salmon's flavor.

Then, it's harvest time. Common methods include electrocution or percussive stunning; AquaBounty isn't yet sure which technique it will use. AquaBounty's salmon are ready to harvest just 18 months after they hatch. It can take up to three years for wild salmon to reach market weight of 4.5 kg.

AquaBounty's recirculating system cleans and recycles water and monitors conditions throughout every stage of a salmon's life. Mechanical filters, such as the Hydrotech drum filters, capture fish waste. Biological filters containing bacteria convert ammonia to nitrite, and then change nitrite into nitrate. Water temperature is kept to between 13 and 15 C.

One advance developed at Cornell, adopted by the Freshwater Institute and installed at AquaBounty's facility, is a "self-cleaning" circular fish tank fitted with strategically placed nozzles, which create a whirlpool effect to mechanically separate waste such as uneaten food. "We get the tank to operate like a teacup or coffee cup, so when you swirl the water, the grounds go to the bottom," Vinci says.

With its recirculating tech, AquaBounty aims to recycle 95 percent of the water used at its Indiana facility. Any water that can't be recycled will pass through an on-site water treatment plant and then go into wetlands, according to Dave Conley, AquaBounty's director of communications.

Even with the newest recirculating tech, Vinci at the Freshwater Institute says there's still room for improvement. "We do use a lot of sensors, and that is one of the weakest parts of the RAS industry, in my opinion," Vinci says. "I can't tell you how many different probes we've tried."

He hopes that the machine-vision technology developed by Aquabyte to count sea lice in coastal fish farms will someday be able to recognize individual fish in indoor aquaculture facilities and monitor their health and well-being. Compared with traditional fish farms, AquaBounty's salmon live in close quarters-there are more than three times as many fish per cubic meter of water at the Indiana facility as there are in traditional fish farms.

Even so, the AquaBounty farm uses no vaccines, antibiotics, or chemical treatments, Conley says. Eyed eggs are disinfected with iodine upon arrival, and technicians clean and disinfect the tanks and incubator trays between each batch (about every three months). Before a fish leaves the nursery, it's screened for eight different bacterial, parasitic, and viral diseases.

Rosalind Leggatt, a postdoctoral researcher at Fisheries and Oceans Canada who contributed to the agency's environmental assessment of AquAdvantage salmon, says the development of recirculating technology has dovetailed nicely with AquaBounty's plans. "The recirculating systems are advancing every six months," she says. "They might go hand in hand together."

Photo: AquaBounty Technologies The embyros in these AquAdvantage salmon eggs have begun to develop eyes.

Now, AquaBounty must try to win over retailers, restaurateurs, and consumers who have plenty of wild-caught and farm-raised salmon from which to choose. AquaBounty plans to produce about 1,200 metric tons of salmon a year. That's a tiny fraction of the 351,136 metric tons of salmon imported in 2018 to the United States.

To entice customers, AquaBounty is touting the environmental benefits of its salmon. The company's website even declares it to be "The World's Most Sustainable Salmon." The fact that this fish consumes far less feed to reach market weight is part of that story, as is the notion that eating farm-raised salmon preserves wild stocks. Decades of overfishing have landed U.S. wild Atlantic salmon populations on the endangered species list, making it illegal to catch them.

AquaBounty also points out that, for U.S. customers, the carbon emissions generated by the transportation of its salmon will be a fraction (1/25, according to the company) of the emissions produced by transporting Atlantic salmon raised on farms in Norway and Chile to the United States. All wild Atlantic salmon and the vast majority of farm-raised Atlantic salmon consumed in the United States are imported-a condition AquaBounty refers to as the "national salmon deficit."

However, there's a smattering of U.S. and Canadian fish farms that raise Atlantic salmon either indoors or along the coasts, and it's not clear how AquaBounty's sustainability claims would stack up against these homegrown options-or against wild Alaskan stocks that are sustainably caught, says Bruce Bugbee, a crop physiologist at Utah State University. "The question here is not whether it's good to eat, and not whether it's profitable. It's [whether] they should be using the word 'sustainable' on their website." he says. "And that's a key question."

Some North American fish farms even tout their products as not genetically modified-possibly to differentiate themselves from AquaBounty's offering. Scientific reviews have repeatedly found that genetically modified (GM) crops are as safe to eat as non-GM crops. And reviews by the FDA and Environment and Climate Change Canada concluded that the environmental risks of AquAdvantage salmon were extremely low or negligible thanks to the containment measures that AquaBounty has put in place.

Starting this month, companies that produce bioengineered food-defined as food containing genetic material that does not occur naturally and which could not have resulted from conventional breeding-are required by the United States Department of Agriculture to apply a new label to their products. At press time, AquaBounty could not confirm whether its fish would carry the labels or not.

Undeterred, AquaBounty is already moving forward with its second product-gene-edited tilapia cleared for sale in Argentina. These fish grow faster, consume less food, and produce bigger fillets than conventional tilapia do.

With its progress in Argentina, Canada, and the United States, AquaBounty is finally nearing the end of its protracted push to bring bioengineered fish to consumers. But being first brings no guarantees-and for AquaBounty, it's time to sink or swim.

This article appears in the January 2020 print issue as "Transgenic Salmon Hits U.S. Shelves."

A correction to this article was made on 6 January 2020.