Last week I noted in my podcast with Jimmy Moore  how expensive genuine wild salmon can cost. Since then, I?ve received a healthy number of emails asking for more info, tips, and the real benefits behind buying ?wild.?
What exactly are salmon ?farms?? How does the farm setting change the nutritional content of salmon? Is there really that much of a difference? Is farmed salmon even worth buying?
First off, salmon farms of some kind make up about 80% of salmon on the market today. (In the United States, the number is higher ? 90% by some estimates.) Thirty percent come from traditional hatcheries, and the remaining 50% are raised in aquaculture or ?open pen nets? just off shore. Farms can ?raise? up to a million salmon at a time. I?ll throw in a visual.
Yup, gets more than a little crowded in there.
Because the farmed salmon are largely confined and fed a steady diet of formulated protein pellets, they?re inevitably fattier. ?But isn?t that a good thing?? you might ask. ?More omega-3s per serving, right?? The answers are ?no? and ?not really? to the above. I?ll explain.
Many assessments have found fewer omega-3s per ounce in farmed salmon compared with wild salmon, but we know the farmed stuff also comes with a hefty (not healthy) wallop of other fats including omega-6s. We then deal with the problem that the omega-6s and omega-3s compete for the same receptors in our bodies. Consequently, the ?net? omega-3 gain will always be less than what you?ll get with a wild serving. Here?s a nifty chart that compares the fat content of some popular wild versus farmed fish varieties (including salmon) from this PDF .
And because the farmed fish are fattier, you?ll get less protein per serving as well.
To truly whet your appetite, I can?t skip the added ingredients you?ll get with a farmed fillet : dioxins, PCBs, fire retardants (those da-n things are everywhere, aren?t they???), pesticides (especially for sea lice), antibiotics, copper sulfate (to take care of algae on the nets), and ? oh yeah ? canthaxanthin (a dye associated with retinal damage used to make gray farmed fish various shades of ?wild? pink).
As for dioxins, PCBs, and fire retardants, they show up in wild varieties as well, but the concentrations are vastly different. Tests have shown that farmed salmon contains 16 times more cancer-linked PCBs than wild salmon . The reason behind this difference? It?s those nasty little protein pellets ? nuggets of mostly mashed fish and fish oil. The intense concentration of toxins from the fish feed builds up in the raised salmon over time ? from fish farm to your fish dinner. Bon Appétit, by the way!
O.K., so you?re no fan of the farm anymore. To cloud the issue further, a ?wild? label may only be telling a half truth. (They?re generally the less expensive ?wild? brands offered in your grocery store.) As I described a few months back in Encore on Omegas , many to most ?wild? salmon actually spend half their lives in hatcheries before being released. While these quasi-wild fish are a better nutritional deal than fully farmed salmon, they still bear the burdens of early exposure to toxins (dioxin, PCBs, etc.) and a less impressive omega 6:3 ratio.
So, what about truly wild salmon? As suggested, the genuine wild article only accounts for about 20% at most of the harvest. Some of the reasons it?s so darn expensive? The flood of farmed fish (and subsequent drop in asking price) has forced many traditional fishermen/women out of business. Add to this scenario the ongoing destruction of wild salmon populations by aquaculture farms, and we all end up paying a premium for the real thing.
Because the farm pens are essentially open, the enormous amount of disease- and parasite- (a.k.a. sea lice ? yum!) laden waste is routinely allowed to contaminate the waters around the farm. Add to this environment the megadoses of pesticide-, toxin-, and antibiotic-laced waste, and the farms create a deadly environment for wild stocks that inhabit the areas. For more on the environmental destruction caused by aquaculture farms, check out these resources from the National Geographic , the New York Times , and the L.A. Times .
Your best bet finally is this: buy less salmon in order to afford the real deal. It?s all about bang for your buck after all. A smaller wild fillet will give you equal nutrition with fewer toxins. Additionally, look for Alaskan over Northwestern salmon. And don?t rule out canned salmon for big savings. Apparently, farmed salmon doesn?t can well , which means the majority of canned salmon is wild. (Pink salmon, the most commonly canned variety, doesn?t contain as much good fats as other kinds.) It?s one way to make salmon a more affordable addition to your Primal-style salad !
Finally, if you do choose to eat farmed salmon, the Environmental Working Group (applying EPA health standards) suggests  eating no more than one serving of farmed salmon a month.
And, of course, I suggest you ensure a healthy daily dose of omega-3s with a good quality, pure fish oil supplement! (We know: broken record. What can we say?)
Your comments, questions, anecdotes, or additions? I look forward to them!
Omega-3 Round Up:
Omega 3 to 6 Ratio 
Omega 3 Food Sources 
Cooking Omegas