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GM fish coming to your plate? So what!

If I have to read another article about ‘Frankenfish’ or ‘Frankensalmon’, I might require psychiatric treatment. These articles evoke images of double-headed salmon and seven-finned abominations. Why all the fuss? In the US, the Food and Drug Administration (FDA) will soon allow genetically modified (GM) salmon made by AquaBounty to be sold–unlabelled–on the US market. There are no plans yet to sell them in the UK, but the story was still covered extensively by the British media.

The villain is a genetically engineered Atlantic salmon that has a single copy of a growth hormone gene from the chinook salmon. This growth hormone is under the control of an antifreeze gene promoter that the scientists at AquaBounty have taken from the eel-like ocean pout. The promoter keeps growth hormone production switched on all year round instead of only in the warmer months. Thus, the salmon progresses from an egg to your plate in just 18 months instead of the normal 3 years.

The consumer should get more fish at a lower cost, and economically everyone benefits. However, consumer groups are in uproar. “[They] jammed up the White House telephone lines last week protesting any approval”, said Eve Mitchell, European food policy adviser at Food and Water Watch Europe. The two main concerns about GM fish are its effects on human health and on the environment.

I’ve read over 20 articles about GM fish and most journalists seem to assume that GM fish are bad for you. They imply that these fish could cause allergic reactions, since the human body has never been exposed to this salmon and seafood in general is highly likely to cause allergic reactions. In my opinion this is a load of wishy-washy argumentation and scaremongering. No data backs these claims. The only decent article I came across that discussed health was Henry Miller’s “Turning gene science into a fishy business”. His conclusion? GM food has not resulted in huge health epidemics so far, although traditional crossbreeding has resulted in new vegetable varieties with elevated levels of toxins and weakness to diseases.

The FDA has given this GM salmon a clean bill of health and has made the data publicly available to appease critics. Health concerns, though widely touted, don’t seem like the greatest problem.

On the other hand, the environmental consequences are worrying. Ron Stotish, the chief executive of AquaBounty, says, "This is perhaps the most studied fish in history…Environmentally this is a very sustainable technology." These are claims that Aquabounty does not back up with easily available information (no third-party research on these GM salmon is available).

The greatest fear is that these salmon could escape and cause the collapse of wild Atlantic salmon. This fear is based on the ‘Trojan gene’ hypothesis initially coined by Howard and Muir in their seminal study in 1999. They inserted a salmon growth hormone gene into the Japanese medaka, which made these fish grow bigger and stronger. Predictably, this resulted in the GM males becoming dominant over normal males and producing more, but less fit, young. The data was plugged into a computer model and extrapolated over multiple generations. The result, assuming that GM males have a 4-fold mating advantage over wild fish, was extinction of the entire population in less than 50 generations.

Applying this hypothesis to AquaBounty’s GM salmon, an escape could lead to quick extinction of wild type Atlantic salmon. AquaBounty have already predicted this scenario and accordingly, their facility is land-based to prevent escapes. AquaBounty also subject their eggs to high pressures that results in eggs with 3 sets of chromosomes, which causes 98% of adult salmon to be rendered sterile. Contamination seems very unlikely.

The problem for AquaBounty is that it needs to sell its GM eggs worldwide to become profitable. The UK has already banned GM fish from being grown in sea- or river-based pens, but will other countries have the appropriate legislation? Escapes from non land-based facilities are not uncommon.

AquaBounty says that even if they manage to escape, their GM salmon are more susceptible to the environment and would be easily outcompeted by wild salmon. They also say their male salmon would not gain mating advantages due to size. A 1997 study by Thomas et al. proves them wrong. Such dubious claims, coupled with the company’s decision not to allow third party research or release all of its data, simply breeds mistrust.

Greater openness and collaboration with academics is sorely needed for environmental and perhaps even health issues to be addressed. Otherwise the deluge of Frankenfood stories will never end and the PR catastrophe that was GM crops will be repeated. Unless we have more information and good scientific research performed on GM food, no one is going to want roasted AquAdvantage salmon with a maple nut crust any time soon.

Edward Duca is a freelance science writer and communicator


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