The story of AquAdvantage Salmon is an interesting one. Aquaculture is one of the world’s fastest-growing sectors in terms of food production with the potential of nipping poverty and malnutrition in the bud. However, this sector’s potential may be short-lived if the rate of global overfishing continues at its current trajectory.

Dr Mark Walton.

According to the Food and Agriculture Organization (FAO) of the United Nations, the number of global overfished stocks has tripled in just half a century. In addition, a third of the world’s assessed fisheries are currently being pushed beyond their biological limits. This not only directly affects the marine environment, but it also threatens the livelihood of millions of people around the world.

One solution that may help to slow down overfishing and cater to the ever-increasing demand for aquaculture, is on-land fisheries.

Why AquAdvantage Salmon is no small fry

AquaBounty is a small biotechnology company headquartered in Maynard, Massachusetts, in the United States (US). AquaBounty grows and sells sustainable Atlantic salmon in a bid to increase aquaculture’s productivity. They achieve this through the research and development of the company’s own genetically engineered AquAdvantage Salmon.

Key milestones AquaBounty has reached in its quest to get
AquAdvantage Salmon to market.

In a webinar presented by The International Service for the Acquisition of Agri-biotech Applications (ISAAA), Dr Mark Walton, chief technology officer of AquaBounty, discussed the company’s progress.

According to Dr Walton, they have had to jump through many regulatory hoops to get their transgenic salmon to market. “The first AquAdvantage Salmon was actually developed in 1989 at Memorial University in Canada. Elliot Entis, who founded AquaBounty, spotted the potential of the fish created the company, and began working towards getting regulatory approval. The first regulatory filings took place in 1995 and in 2015 the US Food and Drug Administration (FDA) approved AquAdvantage Salmon for consumption in the country. A year later, Health Canada also approved AquAdvantage Salmon for consumption.

“We also obtained production approval in Canada prior to 2015, since our salmon hatcheries are located on Prince Edward Island. In 2017 the company purchased a farm in Albany, Indiana. It had an existing aquaculture facility. In 2019 the first AquAdvantage Salmon eggs were moved to the farm and we are now approximately four months away from harvesting our first transgenic AquAdvantage Salmon,” Dr Walton explains.

The company also farms its own line of non-transgenic, conventional salmon on the farm in Indiana. They harvested the first of this salmon in June this year.

AquaBounty wishes to expand its product range on a global scale.

The inner workings of AquAdvantage Salmon

Transgenic organisms contain genetic material into which scientists artificially introduce DNA from an unrelated organism. According to Dr Walton, the transgene in the AquAdvantage Salmon includes a growth hormone-regulating gene from the Pacific Chinook salmon (Oncorhynchus tshawytscha) and a promoter sequence (the sequence of DNA needed to turn a gene on or off) from a fish called the ocean pout (Zoarces americanus). The growth hormone-regulating gene allows the salmon to grow all year, instead of only during spring and summer.

The ocean pout is commonly found in the northwest Atlantic Ocean, off the coast of New England and eastern Canada. Therefore, it has adapted to living in cold temperatures. “The promoter sequence obtained from the ocean pout was harvested from an anti-freeze gene in order to promote the freezing tolerance in AquAdvantage Salmon.

“Seeing as the AquAdvantage Salmon eggs are hatched on Prince Edward Island in Canada, this was a necessary modification to help the salmon thrive in freezing temperatures. Moreover, the promoter sequence also stimulates the salmon’s appetite, which means they grow at a much faster pace compared to conventional salmon,” he adds.

While wild Atlantic salmon (Salmo salar) have two sets of chromosomes, AquAdvantage Salmon have three. As a result, they are triploid. “The induced triploidy by treatment of the salmon eggs renders the salmon completely sterile, which also means we don’t need to worry about any AquAdvantage Salmon breeding with conventional salmon. AquAdvantage Salmon are all female and homozygous, which means each female fish carries only one copy of the transgene,” Dr Walton explains.

AquAdvantage Salmon
Salmon siblings twelve to 15 months after their first feed. The bottom salmon is one of AquaBounty’s AquAdvantage Salmon with the upper two salmon part of their conventional line

According to the FDA’s assessment of the transgenic fish, significantly more AquAdvantage Salmon grow to 100g than non-transgenic salmon within 2 700 degree days.

The advantages of genetically engineered salmon

Some of the other advantages of the AquAdvantage construct is that the fish are 25% more feed efficient than non-transgenic salmon. Seeing that the salmon is also grown inland, operations do not need to be located near saltwater. This translates into reduced transportation costs in getting the product to its intended market.

According to Dr Walton, there is growing pressure on role-players in agriculture to produce food in a sustainable and eco-friendly way. “Fish is an important protein source and approximately 90% of the world’s fisheries are overfished. The ability to increase productivity at current coastal fisheries is minimal. However, the expectation is that aquaculture is going to have to produce 60 million additional tons of fish by 2050 to meet the growing demand and interest in seafood.

“At our farm in Indiana, 95% of the water is recirculated. This is a very efficient way of using water to produce protein,” Dr Walton explains.

AquAdvantage Salmon
AquaBounty’s farm in Indiana recirculates 95% of its water.

Certain conditions must be met for their salmon to be a feasible solution in terms of growing and harvesting salmon in an inland aquaculture facility in any country. “Firstly, there has to be a regulatory framework for genetically modified aquaculture in place so that companies can get regulatory approval.

“Secondly, you must be willing to invest in the infrastructure necessary to get your facility up and running, most of which is fairly expensive. Lastly, a colder climate would be preferable since salmon grows in water with a temperature between 12 and 14°C,” adds Dr Walton.

Consumer sentiment

According to Dr Walton, consumers seem open to trying their salmon. Insights from the proprietary research done in the US and Canada shows that consumer consent is evolving. Up to 70% of participants in the survey were willing to purchase and try the product at least once.

Up to 81% of participants felt neutral to very positive about it. “I think that this is good news for all of us who work in livestock and livestock biotechnology. There is a growing recognition that technology is important in food production. This year’s pandemic has made it more obvious to people that our supply chains may be at risk and that being able to produce protein efficiently and locally is a very positive thing,” he concludes. – Claudi Nortjé, AgriOrbit