Genetically modified or no, farmed salmon a risky proposition
Get ready, folks: A genetically modified salmon, AquAdvantage, may soon be approved by the Food and Drug Administration for use in U.S. commercial fish farming. That is, assuming that an opposition bill that made it halfway through Congress last session doesn't derail the 15-year permitting process, and fierce opposition from environmental groups doesn’t convince the FDA to leave the process in limbo.
The news has got me thinking. How risky is it really, to farm genetically modified salmon that would grow faster, thus using fewer resources and creating less pollution than traditionally farmed fish?
After all, both GM salmon proponents and environmental advocates seem to align on aquaculture as a possible solution to an oceanic world that has become increasingly bereft of wild fish. Take this line, for example:
The depletion of wild stocks due to overfishing and failed management practices in the capture industry leave aquaculture as the only obvious alternative to meet the demand for seafood.
It sounds like it could have come verbatim from environmental journalist Paul Greenberg's book, Four Fish, which chronicled the decline of fish worldwide, and advocated for fish farms as one solution. In fact, the sentence comes from the website of AquaBounty Technologies, the company behind the engineered salmon in question.
If you happen to have come across writing on this topic in the envirosphere, you might think that AquAdvantage frankenfish, once approved by the FDA, were going to escape their cages and swim all over the ocean, polluting the genes of native stocks and destroying the livelihoods of the charismatically crusty, blue-collar workers that make up the Pacific salmon industry while also wreaking havoc on wild salmon runs.
To help ground truth some of these dire warnings, I looked for studies on farmed salmon. A number of researchers have examined the impacts to native fish from escapees of the non-modified farmed salmon industry, which at a worth of $7.2 billion is the second largest aquaculture industry in the world and accounts for 67 percent of the salmon sold worldwide. The industry raises primarily Atlantic salmon, although some Pacific species are also raised.
In a 2005 paper in the journal BioScience, a group of scientists analyzed how escaped farmed fish affected the environments where they ended up. And boy, do they escape. In the North Atlantic, where the majority of salmon farming takes place, an estimated 2 million domesticated salmon escape yearly. And millions of fish have also slip out from farms off the West Coast, possibly to the detriment of the native salmon runs so highly prized by fisherman and conservationists. Atlantic salmon escapees have even been found in Alaskan rivers, one of the last places with healthy wild salmon runs.
These escapees do breed successfully with each other and occasionally with wild salmon, but Atlantic-Pacific salmon hybrids are commonly sterile. The biggest risk appears to be competitive -- like the invasive species they are, juvenile feral salmon in rivers with native runs can outgrow and outcompete native juveniles, limiting their access to food and pushing them out into lower quality habitat, according to research by invasion ecologist John Volpe, who has done extensive work on interactions between escaped and native salmon populations in British Columbia.
Farm escapees can also transmit diseases like sea lice to natives. Martin Krkosek, a scientist who studied sea lice's impact on populations in the Broughton Archipelago, above Vancouver Island, says sea lice from farms drove declines in wild salmon in the archipelago. The British Columbia ministry of agriculture, which has stood steadfastly behind fish farms, debates these claims, but Krkosek stands behind his data. Researchers also fear the spread of viruses like salmon anemia, which recently appeared on the Pacific coast. Viruses spread rapidly in the close quarters of fish farms, and can devastate wild populations.
But let's get back to the AquaBounty fish. Most scientists warning of the risks of aquaculture to native species have called for farmed fish to be grown in land-based operations, so escapees wouldn't make it to the native populations, and for a sterilization technique called "induced triploidy." And guess what: Unlike their non-GM farmed salmon counterparts, AquAdvantage fish (which are all female) are sterilized using this method, and are also grown in land-based operations, which regular fish farms say are too expensive. And AquaBounty recently got a $500,000 grant from the USDA to explore an even more fail-safe sterilization method.
From a 60,000-foot view, then, AquaBounty seems to be doing all of the things environmentalists should be calling on standard fish farms to do.
But there's still that pesky genetic modification aspect. The AquaBounty fish is supposed to grow from smolt to servable in half the time of an ordinary farmed fish thanks to two genes from other fish species: a Chinook one for faster, year round growth and an ocean pout (a sort of sea eel) gene, which doesn't express itself, but allows the Chinook one to work. It's hard to get over such overt meddling with our food’s genetic code; U.S. consumers (yours truly included) are squeamish about it, and, as others have noted, there's no government structure that adequately assesses the public's concerns about genetically modified foods. So while AquAdvantage salmon may be the most studied farmed fish [PDF] in the industry, proven safer on an allergenic and human health level than any other farmed fish in history, it still gets stuck with the ick factor of: "you put a gene from what, where?!"
And, of course, it is difficult to determine the precise environmental impacts of a modified fish getting out into the wild, however unlikely the event is to occur in the case of AquaBounty’s operation. Essentially, it all comes down to acceptance of risk. If we live in a world where consumers demand cheap, farmed salmon (and we do), and a company has come up with a way to do it cheaper and faster, is improved efficiency worth the very small risk that the modified salmon might escape and possible impact the environment?
From a risk perspective, the worries about AquAdvantage are speculative and seem somewhat hyperbolic, since they pertain to a possible altering of our world at some future date in a hypothetical situation where many redundant safeguards fail.
In contrast, the non-modified aquaculture industry is already altering our world, has no redundant safeguards, and therefore, from a conservation perspective, is already failing. In Norway, which pioneered the salmon farming industry in the 1960s, the number of escaped feral salmon in some rivers outnumber the natives, and in some rivers the percent of salmon that are escapees has reached 80 percent -- which doesn't seem to bode well for natives.
It's understandable that consumers and environmentalists are upset at our country's failure to create a holistic regulatory framework that addresses fears over genetically modified organisms' entry into our food supply and natural environments.
Yet seems like, at least right now, the ecological impacts of existing fish farms are the bigger fish in the proverbial sea.
Stephanie Paige Ogburn is the online editor at High Country News. She writes frequently about agriculture and the environment.
Fish image courtesy Flickr user Cheryl Q.
Salmon farm image courtesy Flickr user Sam Mudge