In 2005, the New York Times sent a reporter to buy salmon advertised as "wild" at eight stores in the city. The Times then had the salmon tested and learned that six of the eight pieces of fish, some of which sold for as much as $29 per pound, were farmed, not wild.
The latest chapter in this dispiriting story comes from Consumer Reports August 2006 issue. The magazine's representatives did the same thing the Times reporter did, but in this case bought fish from markets in several states, first in the summer of 2005, then in November and December of 2005, and a third time in March, 2006. The Consumer Reports shoppers bought both farmed and wild salmon and then had them tested for the tell-tale coloring (astaxanthin, a natural carotenoid pigment) added to the feed of farmed salmon so that their flesh will be pink, not gray. Wild salmon flesh is pink because of the crustaceans and algae they feed on. Farmed salmon have a different diet – fish meal and fish oil that doesn't contain the natural pigments.
Of the 27 pieces of salmon bought in the summer – the height of salmon season - all were correctly labeled. But of the 17 pieces of fish bought in November and December (after the season ends), seven turned out to be farmed. In March, shopping was confined to the stores that had sold the mislabeled salmon. This time, all of the "wild" salmon purchased turned out to be farmed. In two stores, the salmon was described as "organic,"a misnomer because no fish are certified organic by the U.S. Department of Agriculture.
Unfortunately, there's no way to tell at a glance whether salmon is wild or farmed, and you certainly can't go around having fish tested. Once you've eaten wild salmon, you may be able to recognize the taste – it's stronger than farmed salmon; the flesh is firmer, too. Bear in mind that you're most likely to find wild salmon between the months of May and September, when the Alaska commercial harvest is in progress. But if the published reports cited here are representative, anything marked "wild" from November through April probably is farmed.
I recommend eating wild Alaskan salmon because it is delicious and a good source of health-protective omega-3 fatty acids. I also have concerns about potential contaminants in farm-raised salmon, although I recognize that this is a complex issue and some farms no doubt have purity standards and raise a good product.
If wild salmon isn't readily available where you live, you can order it online from one of my favorite sources, Vital Choice Seafood (www.vitalchoice.com). The wild Alaskan salmon available from this source is flash-frozen when caught and comes from sustainable, well-managed ocean fishing operations.
If wild Alaskan salmon is too pricey for your food budget, you can buy canned sockeye (red) salmon in the supermarket; it's all wild (sockeye can not be farmed) and will give you the same omega-3 fatty acids found in fresh or frozen Alaskan wild salmon. You can also get the same fatty acids from other cold water fish including, mackerel, sardines, herring, and black cod.
Andrew Weil, M.D.