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Insight & Intelligence : Jan 25, 2013
Transgenic Salmon Prove Tough to Tackle
Many salvos have been fired to prevent the introduction of genetically engineered fish into commercial aquaculture.!--h2>
On January 9, the Clatsop County, Oregon Board of Commissioners unanimously approved a resolution asking the FDA to reject an application from the Maynard, Massachusetts-based company, AquaBounty Technologies, for marketing approval of its genetically-engineered AquAdvantage® salmon.
The Board expressed fears that approval of the AquAdvantage salmon could eventually result in genetically-modified salmon being allowed in ocean-based fish farms, where escape and disease are common. It also notes that the FDA would likely require no labeling to identify the product as genetically altered, which could lead consumers leery of modified foods to avoid all salmon, a significant concern in a county where salmon fishing forms a significant part of the local economy.
This fish fight is but one of many salvos fired to prevent the introduction of genetically engineered fish into commercial aquaculture, as AquaBounty intends to supply the fast-growing transgenic salmon to commercial fish farms. The Center for Food Safety, an advocacy group in Washington, D.C., that is waging a vigorous campaigning against the salmon, said some of the safety studies reviewed by the FDA were based on sample sizes that were too small. The organization’s executive director, Andrew Kimbrell, said, “It is extremely disappointing that the Obama Administration continues to push approval of this dangerous and unnecessary product. The GE salmon has no socially redeeming value; it’s bad for the consumer, bad for the salmon industry, and bad for the environment. FDA’s decision is premature and misguided.”
The Company’s AquAdvantage salmon (AAS) product consists of Atlantic salmon eggs that contain a growth hormone gene from the Chinook salmon, which provides the fish with the potential to reach market size in half the time of conventional Atlantic salmon. Fish grown from AAS eggs are all female and sterile. Additionally, the FDA will require that, were approval of AquaBounty’s New Animal Drug Application (NADA) to be granted, the fish can only be grown in physically contained systems at approved facilities.
Regrettably, misinformation informs irrational opinions from otherwise rational people. For example, the local newspaper reported that the Clatsop County Board of Commissioners resolution tells the public that the much-maligned fish expresses two growth hormone genes: “The AquAdvantage salmon, created for ‘fish-farm’ aquaculture operations, was developed from an Atlantic salmon to which growth hormones from two other species—the Pacific Chinook salmon and the ocean pout—were added.”
In fact, the salmon construct expresses only one growth hormone gene that originated from Atlantic salmon. The transgenic fish contains a single copy of a DNA sequence encoding the Chinook salmon growth hormone and regulatory sequences derived from Chinook salmon and the ocean pout, along with some small synthetic linkers to aid in assembly of the inserts and plasmid.
Unlike wild Atlantic salmon that stop growing during winter, the genetically modified (GM) fish produces growth hormones, and are ready for market throughout the year. The altered fish stop growing when they reach normal size. The fish originate from microinjection of the hybrid gene construct into fertilized salmon eggs back in 1989, to create the first “founder” GM fish. Because of the growth hormone supplied by the added gene, the salmon reaches smolt stage, or the stage at which a freshwater juvenile Atlantic salmon has undergone the physiological changes necessary to be able to survive in salt water.
Back in 2010, the agency had concluded that the salmon “is as safe as food from conventional salmon, and there is a reasonable certainty of no harm from consumption.” For example, the flesh of the fish contains no more growth hormone than regular Atlantic salmon, the FDA said.
The document released last December by the FDA was an environmental assessment and preliminary “finding of no significant impact,” or FONSI, published Dec. 26 in the Federal Register and be available for public comment for 60 days, after which time the Agency could approve the fish for marketing.
The FDA has not provided the Company with an indication of the process or associated timing that will occur after the conclusion of the period for public comment. But additional delays would not shock AquaBounty’s CEO, Ron Stotish, Ph.D., whose company has been seeking FDA approval for the fish since 1995. When he was alerted to the decision he said, “I’ll wait until I see it because I’ve received calls like this before and it never happened.” The company has thus far invested 17 years and $60 million to get the salmon to market.
And fish farming is big business. In 2010, the Fisheries and Aquaculture Department of the United Nation’s Food and Agriculture Organization said that global production of farmed food sea creatures reached 59.9 million tons with the farmgate value of food fish production from aquaculture estimated at $119.4 billion.
But despite environmental concerns and the cost of feeding farmed fish, fish farming is likely to remain a growth industry as it remains a vital source of nutrition to the world, farmed finfish and shellfish now accounting for 47% of all seafood consumption.
Concerns about genetically modified fish in the food supply is at least equaled by the environmental dangers inherent in huge commercial aquaculture. Located inshore or in sheltered areas just offshore, these operations are cheaper and easier than managing a fish farm in a pond or inlet than miles out at sea.
Pollutants and waste concentrate in relatively calm, still water, and fish farms have contaminated coastal waters with waste and antibiotics. Farmed fish, concerned individuals say, may slip out of their enclosures, harming local populations by breeding with them, eating them, or displacing them from their habitats, as well as spreading diseases such as sea lice.
And, opponents say, “There is always going to be a possibility of escape,” as commented Peter Bridson, aquaculture research manager at the Monterey Bay Aquarium in California. “We would oppose the approval of the current application.” Some environmental groups are concerned that the fish might escape from their pens and mate with wild Atlantic salmon.
AquaBounty says, however, that it is unlikely that its strictly female and triploid fish would mate with other salmon. Triploidy, commonly used in aquaculture, renders the fish unable to reproduce, therefore dealing with uncontrolled reproduction issues in the wild.
The company produces, it says, greater than 99% of its fish with triploidy because, as Dr. Stotish told GEN, “We were aware that there would be a concern. Also, also if we are producing a high-value fish, we don’t want it available for other people to breed in an unregulated manner.”
AquaBounty has also said, to allay concerns that fish farmers will file for permits to keep the salmon in nets in the open ocean in order to lower costs, that it wouldn’t sell the fish to farmers who do not have enclosed, inland tanks. A condition of use for the pending FDA application is the fish will be grown only in FDA-approved, land-based contained systems.
With regard to the genetic construct in the fish, AquaBounty’s CEO told GEN that “this is a very straightforward construct. The FDA disclosed over 200 pages of data and analysis for the Veterinary Medicine Advisory Committee meeting in 2010.” Opponents have misrepresented or criticized much of this information, he says.
He further explained that the introduction of the first founder fish was “way back in 1989 and it has been bred conventionally for than 12 generations by classical methods.” The gene construct was initially made in the late 80’s–early 90’s, with the first introduction into “founder” fish back in 1989. It has been bred conventionally since that time.
And, he pointed out, the company has focused particularly on this Atlantic salmon and knows a lot about it. The fish, he says, “grows very slowly for the first two years of life. It spends part of its life in very cold water, with its growth regulated by photoperiod, or sunlight, water temperature, and availability of food. Therefore, when food is not plentiful and it’s cold, the fish doesn’t grow very much.” A young salmon, he explained may weigh only 50–100 grams in the wild at two years, meaning “that you need to keep the fish around to get it to market weight.” The engineered Atlantic salmon reaches market weight in 18 months instead of 36, thus halving the time needed.
Dr. Stotish further notes that “land-based cultivation can’t be done economically with Atlantic salmon that exist today, which remains impractical unless you can sell the fish for a premium price.” Alaskans are worried about reduction in salmon runs and are overfishing their own fisheries. “What better way than to take pressure off wild salmon populations than with environmentally sound fish farming.”
Properly managed science, he says, could offer a safe and environmentally sustainable solution to the developing food crisis due to overfishing of the worlds’ oceans. “This fish contains nothing that a consumer of salmon wouldn’t already eat.”
Patricia Fitzpatrick Dimond, Ph.D., ([email protected]) is technical editor at Genetic Engineering & Biotechnology News.
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