Thursday, 3 July 2008

Farmed versus Wild Salmon

Easy. Wild salmon's better.
But why?

First- a brief history:

Because wild salmon is only catchable from late May to late September (and even during the season, can be quite pricey), in the 1960s Norway invented a system of farming salmon in pens along the coastline. Today four countries produce about 98% of the world’s farmed salmon: Norway, Chile, the UK (mainly Scotland) and Canada. Most of the US’ farmed salmon comes from Canada and Chile.

Choosing wild salmon is better for the environment

  • Farmed salmon are grown in floating netcages and fed processed anchovies, sardines, herring- all fish humans eat, thus reducing the amount of fish available for human consumption. Wild salmon eat deep-ocean small fish that are generally not eaten by humans. It takes a lot of fish- 3-5 lbs- to provide enough fish meal and fish oil to add 1 lbs of weight to a farmed salmon. Moreover, the small fish fed to the farmed salmon are caught closer to shore and are therefore more contaminated with PCBs, pesticides and dioxins.
  • According to a 2003 study, a salmon farm of 200 000 fish releases as much fecal matter as 65 000 humans, killing marine animals and plants and causing harmful algae to grow.
  • Over 1 million Atlantic salmon have escaped from their netcages into British Columbia waters. Farmed salmon have more diseases and can carry sea lice that eat fish flesh. The concern is not only that they spread their diseases but that they breed with the wild salmon and weaken their genetic makeup- farmed salmon have smaller fins and larger bodies- thus affecting their ability to survive.

sing wild salmon is better for your health
  • A study that analyzed 700 wild and farmed salmon from 8 different countries found that farmed salmon contained 7 times higher levels of pesticides, PCBs and dioxins than wild salmon and eating it can increase your risk of getting cancer (see “putting it into perspective” below). As a result of this study, the US Environmental Protection Agency recommends you eat no more than 1 meal a month of farmed salmon from Washington state and Chile- the places with the least-contaminated farmed salmon. Farmed salmon from Canada, Maine and Norway were found to be twice as contaminated as the salmon from Washington and Chile, therefore the recommendation is to eat no more than 1 meal every 2 months of fish from those places. Lastly, farmed salmon from Scotland and the Faroe Islands were so contaminated that it's recommended you not eat it more than once a year!
  • Salmon farmers often use antibiotics to help control the spread of disease. In fact, farmed salmon receives more antibiotics by weight than any other livestock. Many of the antibiotics used are the same ones used to treat human infections and traces of these substances are passed on to consumers and can contribute to the dangerous increase of antibiotic-resistant disease worldwide.
  • Farmed salmon contains higher levels of unhealthy saturated fats and lower levels of beneficial omega-3 fatty acids because of the makeup of their feed—fish meal, fish oil and various by-products and filler.

Putting it into perspective

Your risk of cancer does increase if you eat pesticide-contaminated farmed salmon regularly. If you eat 6oz of farmed salmon from Washington or Chile once a month, your risk of getting cancer rises by 1 in 100 000.

Another way of looking at it

According to current stats, 33 000 of every 100 000 people will be diagnosed with cancer if they live to the age of 80.
If all 100 000 ate farmed salmon once a month, the number would rise to 33 001. If all 100 000 ate farmed salmon once a week, the number would rise to 33 004. If the farmed salmon was from Canada, the number would be 33 008.

Now, about 5000 of every 100 000 Americans will die of a heart attack, according to some estimates. If these 100 000 ate salmon- farmed or wild- once a week, the research estimates that there would be 1500 less deaths.

We know that cold-water fatty fish are great sources of the heart healthy DHA form of omega 3 that has a huge impact in lowering your risk of getting a heart attack or stroke. This is why it’s recommended you eat these fattier fish 2-3 times a week.

However, if you don’t want to eat fish- you can now purchase algae-oil supplements that provide the same type of beneficial DHA omega 3.
Fish oil supplements have been found to have very little, if any, contaminants.
You want to aim for 1 g of omega 3 from these sources but always talk to your doctor before taking any of these supplements!

Other tips and facts

Grilling your salmon and letting the juices drip away, cooking it until it reaches an internal temperature of 175 degrees Fahrenheit and removing the skin before eating it will reduce the amount of contaminants by at least half.

Farmed organic salmon means that the pens are less crowded and the fish are exposed to less pesticides.

All salmon from Alaska is wild. Chinook is the most contaminated, Chum is the least contaminated

Most salmon sushi is from farmed fish.

Most canned salmon is from Alaska therefore wild. It will have more sodium so buy salmon canned in water and rinse under water for at least a minute to reduce the sodium by about 40%.

Smoked salmon is usually farmed. Although the heating kills some of the contaminants, smoking creates others.

Farmed trout is high in omega 3 and less contaminated than salmon.


Schardt D. Farmed salmon under fire. CSPI: Nutrition Action Healthletter. June 2004.


Anonymous said...

wow awesome info Sybil!


nc said...

Thanks for the info. You saved me from doing the lenghty research. I need to eat more fish, but only wild!!!