While “wild” and “farmed” conjure up profoundly different images (one of happy salmonand the other of hormone-stuffed Frankenfish),the differences between the two aren’t as troubling as one might expect — at least, not in terms of health. We took a closer look at the salmon industry so you can finally decide which is worth your cash.
Which is Better When it Comes to Health?
With a nutritional profile full of heart-healthy omega-3 fatty acids, salmon is one of the most popular fish among health-conscious folk, and about 70 percent of our supply is raised in farms (via “aquaculture”) to meet global demand. Between 1990 and 2010, the world’s total production of farmed salmon jumped from 299,000 tons per year to 1.9 million, an increase of over 600 percent. But is more farming a step in the right direction?
While it provides some health benefits, fish farming can have some seriously harmful environmental impacts. Salmon are typically bred inside of densely-populated net-cages, which float in natural bodies of water and allow for all sorts of damage to the seabed and local sea life: They’re known to leach pesticides, viruses, antibiotics, and heavy metals like zinc and copper into their surrounding waters. Farmed salmon are also known to escape from farms and interbreed with native fish, damaging local gene pools and creating infertile spawn.
However, the most serious risk involved with farming tightly-packed salmon might be the spread of sea lice. One study found that, typically, 80 percent of local salmon die from farm origin sea lice outbreaks, and incidences of 95 percent mortality are not unheard ofEpizootics+of+wild+fish+induced+by+farm+fish.+Krkosek+M,+Lewis+M.A.+et+al.+Centre+for+Mathematical+Biology,+Department+of+Mathematical+and+Statistical+Sciences,+University+of+Alberta,+Canada.+Proceedings+of+the+National+Academy+of+Sciences,+U.S.A.+2006+Oct+17;+103(42):+15506-10.. All of these factors contribute to farming’s negative environmental footprint: A study of farms in Scotland, Ireland, and Canada showed many cases of aquaculture reducing nearby salmon and other fish populations by more than 50 percentA+global+assessment+of+salmon+aquaculture+impacts+on+wild+salmonids.+Ford+J.S.,+Myers+R.A.+Department+of+Biology,+Dalhousie+University,+Halifax,+Canada.+Public+Library+of+Science+Biology+2008+Feb;+6(2):+e33..
If the only consideration is health and price, there’s nothing wrong with enjoying farmed salmon, particularly if it hails from Chile or Western Canada. If the environment is more of a concern, the research seems to favor the wild variety.
In any event, it’s important to remember that while salmon is a healthy food, it’s not a unique source of any nutrients. A serving of oily fish like herring and mackerel contains just as many omega-3s as salmon. If chemicals are of concern, oily fish that are lower on the food chain, such as sardines and anchovies, tend to harbor far fewer toxins. Any issues one might have with salmon’s risks can be mitigated with a varied diet — something that’s tremendously important both for one’s health and for the environment.