August 2016 Issue

Seafood: Genetically Engineered Salmon
By Carrie Dennett, MPH, RDN, CD
Today's Dietitian
Vol. 18 No. 8 P. 18

Despite FDA approval, questions remain about whether this controversial fish will make it to America's dinner plates.

The USDA's 2015–2020 Dietary Guidelines for Americans recommend that adults eat at least 8 oz of seafood per week for cardiac and prenatal health at the same time that most of the world's fisheries are being overexploited.1 Fish that's genetically engineered to quickly reach mature size has been suggested to be the solution to satisfying consumer demand while protecting wild fish populations. However, many consumers, retailers, and environmental groups disagree.

In November 2015, the FDA approved the genetically engineered (GE) AquAdvantage Salmon for production and human consumption.2,3 In March 2016, a broad coalition of environmental, consumer, commercial, and recreational fishing organizations filed suit against the FDA challenging that decision.4 The stakes are high: Because the AquAdvantage Salmon is the first genetically modified animal approved for human consumption, any legal ruling could set a precedent.

What Is GE Salmon?
AquAdvantage Salmon has been genetically engineered to grow twice as fast as its non-GE, farm-raised Atlantic salmon counterpart. The genetic modification comes from the insertion of a piece of DNA (an rDNA construct) that contains part of the Pacific Chinook salmon growth hormone gene and the promoter sequence from the ocean pout, a deepwater ocean fish that belongs to the eelpout family. A promoter is a sequence of DNA that turns on the expression of another gene.5 Whereas regular farmed Atlantic salmon take 32 to 36 months to reach maturity, the increased growth hormone output reduces the AquAdvantage Salmon's timetable to 16 to 18 months.6

Meeting Consumer Demand
As consumer thirst for seafood increases, there's concern about whether wild fisheries can meet the demand without depleting fish populations. According to the Monterey Bay Aquarium Seafood Watch, 90% of the world's fisheries are "fully exploited, overexploited, or have collapsed."7 About 90% of the fish consumed in the United States is imported, with one-half being wild-caught, according to the National Oceanic and Atmospheric Administration. Atlantic salmon is the second largest import, trailing only shrimp.8

The Food and Agriculture Organization (FAO) of the United Nations estimates that fish consumption in the 1960s was about 22 lbs per person per year. Today, that rate has increased to approximately 42 lbs per person per year.9 Currently, Americans eat an average of one meal of fish per week.8 If every American decided to follow USDA recommendations, demand would increase significantly. As it stands, the FAO reports that average global per-capita consumption is expected to increase 30% between 2010 and 2030.10

Concerns and Alternatives
Farmed salmon is one possible remedy to protecting against further depletion of wild populations. However, it's a solution that presents its own problems. Seafood Watch, a program that helps consumers choose seafood that's fished or farmed in ways that protect sea life and habitats, lists farmed Atlantic salmon on its "avoid" list, citing farming practices that can harm other marine life or the environment.11,12 Farmed salmon in open net sea cages can escape, which is a problem that's of particular risk during storms, since nets can get damaged or fish can escape due to rough waters. In addition, diseases, parasites, and waste products can flow out of the open nets and into surrounding coastal waters.13

According to AquaBounty's FDA-approved petition, the plan is to grow GE salmon eggs in a facility on Prince Edward Island, Canada, then transport them to a land-based indoor recirculating aquaculture system (RAS) in Panama to hatch and mature before being shipped back to the United States for sale and consumption.2,3 Indoor RAS facilities eliminate interactions between farmed fish and the environment.14

It's difficult to gauge the exact impact of GE fish escaping into the environment without actually allowing them to escape, an option with potentially serious consequences. Therefore, the focus remains on containment while data are gathered in environments that simulate nature.15 Research published in 2013 found that fertile AquAdvantage Salmon could interbreed in a lab setting with the closely related wild brown trout. Further, the hybrid offspring grew faster than their wild-type counterparts and showed a competitive advantage over their parent species in at least some seminatural conditions. However, it's unclear whether this would be observed in actual wild environments.16 AquaBounty says the hybrids themselves wouldn't be fertile, adding that all AquAdvantage Salmon currently being produced are sterile.17

FDA Approval and the Road to Market
AquAdvantage Salmon took the long road to FDA approval. In 1989, Canadian researchers found that inserting a Chinook salmon growth hormone gene sequence into the genome of an Atlantic salmon could greatly reduce the time to market.17,18 Seven years later, Massachusetts-based AquaBounty Technologies, a biotechnology company founded in 1991, submitted AquAdvantage Salmon for FDA approval.

In 2009, the FDA issued guidelines for producers of GE animals and clarified its statutory and regulatory authority.19 Then, in June 2015, the agency issued a revision based on public participation.20 Before approving AquAdvantage Salmon for market, the FDA accepted public comments and released draft environmental documents for public review. The agency also examined data from AquAdvantage Salmon and non-GE farm-raised Atlantic salmon and found no biologically relevant differences.5 Based on those findings, the FDA determined that AquAdvantage Salmon has a nutrition profile comparable to that of non-GE farm-raised Atlantic salmon and is just as safe to eat.21 In its environmental assessment, the FDA concluded that AquAdvantage Salmon doesn't present an environmental risk, noting that the fish are sterile and raised in confinement.22,23

In May, Health Canada, the department of the Canadian government responsible for national public health, approved AquAdvantage Salmon for commercial sale. The safety assessment considered how AquAdvantage Salmon was developed, how its composition and nutritional quality compares with nonmodified salmon, the potential for GE salmon to be toxic or cause allergic reactions, and the salmon's health status.24

Still, after all of this research, will GE salmon be showing up on dinner plates anytime soon? For several reasons, the answer likely is "no." In January 2016, in accordance with language in a spending bill passed by Congress and signed into law by President Obama last December, the FDA issued an import ban on GE salmon (AquAdvantage Salmon is produced outside of the United States) until labeling standards are established.25 Before that edict, the FDA had decided that labeling would be voluntary.26

Even without these logistics to overcome, there's a necessary ramp-up to getting AquAdvantage Salmon ready for market. "Our current production capacity is about 100 tons per year. To put that in perspective, the global salmon farming industry produced 2.5 million tons of salmon in 2014. We will not have any market-size fish for a year or more, and then only in limited quantity," says AquaBounty spokesperson Dave Conley.

Another hurdle to getting GE salmon on Americans' tables is pure business. Major retailers such as Costco, Whole Foods, Trader Joe's, Target, Kroger, and Safeway, as well as many restaurants and seafood suppliers, have said they won't sell GE salmon.

Legal Challenges
The FDA regulates GE animals under the "new animal drug" provisions of the Federal Food, Drug, and Cosmetic Act, which defines a drug as "an article (other than food) intended to affect the structure or any function of the body of man or other animals." Because the DNA insertion is intended to change the structure or function of the GE animal's body, the FDA considers it to be a drug.19

The categorization of genetic engineering as a drug is one of the focal points of a lawsuit brought in March by a broad coalition of environmental, consumer, commercial, and recreational fishing organizations, represented by legal counsel from the Center for Food Safety and Earthjustice.4 The plaintiffs are challenging the FDA's decision to approve AquaBounty's petition on the following grounds:27

• Genetic engineering isn't the same as a drug.
• Concern that GE salmon may escape into the wild and have adverse effects on wild salmon populations, including competing for resources, spreading disease, and interbreeding.
• Concern that the FDA approved AquaBounty's petition based on the Canada and Panama facilities, even though AquaBounty has stated publicly that it has plans to expand to additional facilities around the world, including the United States, and to sell AquAdvantage Salmon globally. The plaintiffs argue that the FDA didn't consider this expansion when assessing environmental impact.

The FDA's decision to approve AquAdvantage Salmon was precedent setting, as will be any legal decision. As of press time, a motion to intervene was scheduled for August 4.28

— Carrie Dennett, MPH, RDN, CD, a nutrition columnist for The Seattle Times, speaks frequently on nutrition-related topics. She also provides nutrition counseling via the Menu for Change program in Seattle.


1. US Department of Agriculture, US Department of Health and Human Services. 2015–2020 Dietary Guidelines for Americans. 8th ed. Washington, DC: US Government Printing Office; 2015.

2. AquAdvantage Salmon approval letter and appendix. US Food and Drug Administration website.
. Updated November 19, 2015.

3. FDA takes several actions involving genetically engineered plants and animals for food. US Food and Drug Administration website. Updated May 27, 2016.

4. Lawsuit challenges FDA's approval of genetically engineered salmon. Center for Food Safety website. Updated March 31, 2016.

5. AquAdvantage Salmon fact sheet. US Food and Drug Administration website.
. Updated December 21, 2015.

6. Technology. AquaBounty website. Accessed May 21, 2016.

7. Wild seafood. Monterey Bay Aquarium Seafood Watch website. Accessed May 23, 2016.

8. Basic questions about aquaculture. NOAA Office of Aquaculture website. Accessed May 23, 2016.

9. Food and Agriculture Organization of the United Nations. The state of world fisheries and aquaculture: opportunities and challenges. Published 2014.

10. The World Bank. Fish to 2030: prospects for fisheries and aquaculture. Published December 2013.

11. Consumer guide. Monterey Bay Aquarium Seafood Watch website. Accessed May 23, 2016.

12. Monterey Bay Aquarium Seafood Watch. Seafood watch standard for aquaculture.
. Published October 30, 2015.

13. Aquaculture. Monterey Bay Aquarium Seafood Watch website. Accessed May 23, 2016.

14. Bregnballe J. A guide to recirculation aquaculture: an introduction to the new environmentally friendly and highly productive closed fish farming systems. Published 2015.

15. Devlin RH, Sundstrom F, Leggatt RA. Assessing ecological and evolutionary consequences of growth-accelerated genetically engineered fishes. BioScience. 2015;65(7):685-700.

16. Oke KB, Westley PAH, Moreau DT, Fleming IA. Hybridization between genetically modified Atlantic salmon and wild brown trout reveals novel ecological interactions. Proc Biol Sci. 2013;280(1763):20131047.

17. AquaBounty. AquaBounty response to new research by Memorial University. Published May 29, 2013.

18. Du SJ, Gong ZY, Fletcher GL, et al. Growth enhancement in transgenic Atlantic salmon by the use of an "all fish" chimeric growth hormone gene construct. Biotechnology (N Y). 1992;10(2):176-181.

19. US Food and Drug Administration. FDA issues final guidance on regulation of genetically engineered animals. Published January 15, 2009.

20. US Food and Drug Administration, Center for Veterinary Medicine. Guidance for industry #187: regulation of genetically engineered animals containing heritable recombinant DNA constructs.
. Published June 2015.

21. US Food and Drug Administration. FDA has determined that AquAdvantage Salmon is as safe to eat as non-GE salmon. Published November 2015.

22. US Food and Drug Administration, Center for Veterinary Medicine. AquAdvantage Salmon: environmental assessment.
. Published November 12, 2015.

23. US Food and Drug Administration, Center for Veterinary Medicine. Finding of no significant impact: AquAdvantage Salmon.
. Published November 12, 2015.

24. Novel food information — AquAdvantage Salmon. Health Canada website. Updated May 19, 2016. Accessed May 26, 2016.

25. Import alert 99-40: genetically engineered (GE) salmon. US Food and Drug Administration website. Updated January 29, 2016.

26. Guidance for industry: voluntary labeling indicating whether foods have or have not been derived from genetically engineered plants. US Food and Drug Administration website.
. Updated December 3, 2015.

27. United States District Court for the Northern District of California. Institute for Fisheries Resources et al v. Burwell et al. Published 2016.

28. United States District Court for the Northern District of California. Calendar for: Judge Vince Chhabria. Updated July 5, 2016.