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Are Genetically Modified Salmon Headed to the Supermarket?

The FDA is poised to decide whether biotech animals should be sold as food.
September 7, 2010

A genetically engineered strain of Atlantic salmon that’s designed to grow twice as fast as its unaltered cousins may soon be eligible for dinner. After a decade of debate, the U.S. Food and Drug Administration this month will review an application to market fish created by AquaBounty Technologies, a company headquartered in Waltham, MA. If approved, the salmon would become the first “transgenic” animal–one that has DNA from another animal–in the world to be sold for human consumption.

Big fish: A genetically engineered salmon (in back) designed to reach market size twice as fast as an unaltered fish (in front) will come under FDA review this month. Both fish in the image are the same age.

The agency released a report on Friday stating that the animals appear to be as safe to eat as traditional salmon and do not pose a significant risk to the environment. However, it will likely not make a final decision regarding the salmon until the weeks after the hearing.

“The decision will affect whether and how transgenic animals are approved and regulated here and around the world,” says Eric Hallerman, head of the Department of Fisheries and Wildlife Sciences at Virginia Polytechnic Institute and State University. Other genetically modified animals are waiting in the wings. They include other types of fish, cattle that are resistant to mad cow disease, and the so-called enviro-pig, which was designed to generate more ecofriendly manure. Even if the government approves, however, it remains an open question whether food producers and consumers would accept such animals.

The FDA will decide not only whether to allow the fish, but also whether it would require it to be labeled as genetically modified. That could have a strong impact on how consumers respond. Genetically modified plants, such as the soybeans used in tofu, do not carry special labeling. Although these crops generated strong suspicion when first introduced over a decade ago, many have now become seamlessly integrated into the food supply.

The new fish wouldn’t be bigger than conventional salmon–but they would reach full size twice as fast. Created in the early 1990s, the salmon were engineered to carry the gene for growth hormone from a closely related species, Chinook salmon. (Conventionally bred Atlantic salmon produce little of this hormone in cold weather.) A short stretch of DNA derived from a third type of fish is added to control the gene’s ability to produce the hormone. This genetic on-switch increases hormone production during the salmon’s first year of life, leading the animals to reach market size in about half the time it takes their conventionally bred counterparts. The engineered fish also convert food into flesh more efficiently. As a result, AquaBounty, which aims to sell eggs to fish farmers, says the technology will make salmon farming more economically viable by reducing the time producers need to rear the fish.

At the hearing, scheduled for September 19 to 21, a panel of experts convened by the FDA committee will decide whether the fish are safe to eat, and whether they pose environmental risks. It’s this latter question that has been the topic of intense debate and extensive research over the last few years; some fisheries scientists and ecologists worry that the fish might escape their farms and endanger wild salmon strains. Farmed salmon, which now generate most of the world’s salmon supply, are typically grown in ocean pens, and the animals can escape through broken nets. Lab studies suggest that when food is scarce, the engineered salmon can outcompete unaltered ones.

AquaBounty’s president, Ronald Stotish, says the company has addressed these concerns by making the fish sterile, prohibiting mating with wild fish, and by growing them only in indoor tanks. Stotish says there’s an environmental benefit to this approach: producers can grow salmon closer to where the fish will be sold, reducing transportation costs.

But not everyone agrees. “Land-based aquaculture uses huge amounts of water and energy to keep that water flowing,” says Anne Kapuscinski, professor of sustainability science at Dartmouth College. “I am really skeptical that companies can make money raising salmon in a highly contained land-based facility.”

Kapuscinski also worries that requirements limiting farming of the fish to pools on land will not adequately contain the risk of escape. “What about other countries? Salmon farming is global,” she says, with large farms in Chile and Tasmania. “If it’s not highly regulated and carefully contained, there could still be cases of escape.”

For consumers, the primary concern is likely whether the fish are safe to eat. Stotish says that extensive testing shows that the nutritional content of the engineered fish is the same as that of traditionally bred Atlantic salmon. It also has no greater likelihood of prompting allergic reactions, he adds.

While it’s unclear how consumers would respond to engineered salmon, the fish farming industry appears pessimistic. Trade groups–which are already sensitive to criticism of their industry–such as the International Salmon Farmers Association, the Canadian Aquaculture Industry Alliance, and the British Columbia Salmon Farmers Association, have come out against the commercial use of genetically modified salmon. “We don’t support production of transgenic fish for food consumption until it has been proven safe and the market demands it,” says Ruth Salmon (yes, that is her name), executive director of the Canadian Aquaculture Industry Alliance. “We have not seen any market demand at this time.”

AquaBounty’s long journey–the company first filed for regulatory approval in 1995–highlights the challenge of commercializing transgenic animals for food. It was only in 2008 that the FDA outlined how it would regulate genetically engineered animals meant for human consumption; rather than being reviewed like other foods, they are regulated as new animal drugs, reflecting their strange status in the regulatory landscape.

Some scientists say these hurdles have slowed down the field, and may push cutting-edge research to other countries. For instance, James Murray, a professor of animal science at the University of California, Davis, has genetically engineered goats that produce a human immune protein, which he hopes will help children suffering from severe diarrhea. He has moved some of his research to Brazil, which he says has enacted regulation and offered funding to support research and commercialization of transgenic animals.

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