Most of what people think they know about aquaculture salmon is obsolete, or wasn’t true in the first place
FROM FOOD SAFETY NEWS – by Ross Anderson | May 01, 2012
Food Safety News writer Ross Anderson recently toured fish farms and processing plants in southern Chile as a guest of Salmon of the Americas, a Chilean trade organization. This is the second of two reports.
Puerto Montt, Chile – In the Pacific Northwest, where I’ve lived and worked for 40 years, salmon is more than a commodity. It’s a regional icon and an article of faith, part of a regional doctrine that dictates: thou shalt eat wild salmon only, for farmed salmon is a blasphemy.
As a journalist with agnostic tendencies, I’ve never really subscribed to this belief. But I’ve always been a tad suspicious of farmed salmon. I suppose it has to do with vague recollections of something I read about the use of antibiotics, or to the label we frequently see on salmon packages: “color added.”
So when I jetted off to Chile a few weeks ago, it was with a twinge of skepticism.
Over the following five days, I saw a lot of fish. I walked the galvanized steel catwalks around floating netpens the size of three football fields and 100 feet deep – pens that contained millions of Atlantic salmon, shadowy missiles milling beneath the surface until the automatic feeders spring to action and the surface suddenly boils with bright, silvery, hungry salmon that reminded me of an Alaska spawning run.
I toured factories that resemble surgical wards, with scores of workers draped in white gowns, masks and rubber boots, stepping through disinfectant baths between rooms. I watched men and women trimming gorgeous, red fillets into meal-size portions for freezing, then for shipment to markets around the world. I listened to workers explain what they do, and what they’ve learned from the last few years, when an invading virus killed millions of fish, and almost killed the industry.
At each stop, I asked questions about our perceptions of farmed salmon, about antibiotics and Omega 3 fatty acids and food coloring.
Industry leaders, of course, assure us that all is well. So in recent days, I’ve consulted with several independent experts, including Dr. Mike Rust, aquaculture researcher at the Northwest Fisheries Science Center in Seattle; Dr. John Forster, a marine biologist and aquaculture expert based in Port Angeles, WA; and Gary Marty, a fisheries expert with the Canadian Agriculture Ministry and a professor at the University of California. Here’s what I’ve learned.
What’s the deal with “color added?” OK, this is one that bugged me. And unnecessarily so, it seems. Wild salmon get their color from eating algae, insects, shrimp or other food containing “astaxanthin,” the same natural pigment that makes carrots orange. Fish farmers achieve the same result by adding minute amounts of astaxanthin, natural or synthetically produced, to the food pellets. “You’ll find the same stuff on the shelf at your local health food store,” Marty reports.
What’s the risk? None, Rust agrees. “It’s also used in poultry, to make egg yolks more yellow. And it’s actually a bit of an antioxidant.”
Are farmed salmon laced with antibiotics? Aquaculture experts explain that antibiotics have been used to ward off diseases that would sicken or kill fish – in precisely the same way they are used in many common foods. The antibiotics are added to the fishfood, primarily in the early, freshwater stages of their development, when the fish are most susceptible to disease. Two years later, when those fish are harvested, there is little or no trace left in the fish.
In Norway and Canada, those antibiotics have been almost completely eliminated, replaced by vaccines which do the same job. Chile’s warmer waters, however, are susceptible to “salmon rickettsial syndrome,” or “SRS,” which affects fish, but not people. So the industry continues to use antibiotics in the early stages, while awaiting a vaccine to ward off the disease.
“Disease is part and parcel of all biology, whether it is apples or corn or salmon,” Forster says. “But it gets more attention because aquaculture tends to fall under the authority of fisheries agencies instead of agriculture.”
Don’t farmed salmon lack the Omega 3 fatty acids, along with all their health benefits? No. The experts agree that the Omega 3 benefits are derived from what fish eat, and that pellet-fed farmed salmon offer as much, and in some cases more of those benefits than wild fish.
If there is an issue of food safety, Marty says, it might be that there is a higher risk of Listeria in farmed fish. In one sampling of Canadian fish, two of 40 tested positive for Listeria – a level similar to poultry and other meats. But Listeria is quickly and efficiently killed by cooking, he adds.
There are risks with any food, he says. “But the benefits of eating farmed salmon far exceed the risks.”
Rust agrees. “I’d have to say that 95 percent of what people think they know about aquaculture salmon is either obsolete, or was not true in the first place.”
And so it goes. There are other issues, of course. Environmental critics contend that those floating mega-farms generate an enormous amount of waste that sifts down through the nets and creates ecological deadzones on the sea bottom. They say that escaped fish pose a risk of competing with native fish. And they argue that fish-farms mine the ocean of important forage fish to be converted into fish-food pellets.
Chile’s salmon farmers now acknowledge that their critics have been right on some issues. The industry grew too fast, packed too many fish into their farms, leaving them susceptible to the virus that nearly brought the industry to its knees just three years ago. But they say they’ve learned their lesson, and are doing a far better job of dealing with the ecosystem they depend on.
Still, the industry is still young. Perhaps the jury is still out on those environmental issues.
But food safety doesn’t appear to be one of them. So, later this month, when my wife and I host a neighborhood gathering, there will be farmed salmon on my barbecue.
Photos courtesy WarnerHanson