There are some excellent, small, organic fish farms out there. However, the majority of the fish you will buy in the grocery store or be served in the restaurant is from the nasty big farms. The environmental impact of these farms deserves a blog - One of the biggest concerns is the amount of food required to raise farmed salmon. It generally takes three pounds of wild fish to grow one pound of farmed salmon. The environmental impact of salmon farming is still increasing as global production continues to rise.
Most salmon are farmed in open pens and cages in coastal waters. Waste from these farms is released directly into the ocean. Parasites and diseases from farmed salmon can spread to wild fish swimming near the farms and escaping farmed salmon can harm wild populations.
But for now I want you to know about the nutritional impact on you.
A large survey yet of pollutants in salmon, reported in the January 9, 2004 issue of Science, clearly indicates that because of the feed they receive, farmed fish have much higher levels of carcinogenic pesticides (specifically polychlorinated biphenyls or PCBs, and two other organochlorine compounds, dieldrin and toxaphene) than wild caught salmon. Although this study was a few years ago, things are no better.
The massive study, funded by the Pew Charitable Trusts' Environment program, was conducted by six scientists who analyzed about 700 salmon from around the world for more than 50 contaminants. For 13 of 14 of the organochlorines tested, farmed salmon were more contaminated than wild ones. Levels were highest in European farmed salmon, followed by those from North America. Chilean farmed salmon were the cleanest. The oil and meal the farmed salmon were fed exhibited a similar pattern.
For the most contaminated fish-from farms in Scotland and the Faroe Islands-a quarter of one serving (55 grams of uncooked salmon) per month was the maximum amount that could be eaten before boosting cancer risk, according to EPA guidelines. One half-serving (110 grams) of farmed salmon from Canada or Maine could be eaten per month without adding to significant risk, and one serving (220 grams) per month would be acceptable for fish from Chile or the U.S. state of Washington.
In comparison, according to EPA guidelines, it is considered safe to eat one serving (220 grams) of some types of wild salmon from Alaska or British Columbia eight times a month.
It is strongly recommended that pregnant women, nursing mothers and women of childbearing age avoid eating all farm raised fish including salmon. Organochlorines damage the developing endocrine system, immune system, and brain. Once consumed, these toxic compounds are stored in body fat where they can remain for decades until they are passed to a woman's fetus during pregnancy or excreted in her breast milk.
How to get wild salmon:
Fresh Salmon The season for fresh wild salmon begins around late February so ask your fishmonger about its availability. Salmon will become more affordable in the succeeding months as increasing numbers return to fresh water to spawn. Wild salmon is a great addition to your menu because it is rich in essential omega-3 fats and also is an excellent source of high quality protein. While it is difficult to get fresh wild salmon during certain times of the year because the season for wild salmon begins in late February and ends in November, frozen or previously frozen salmon is available. If you don't see previously frozen salmon on ice or frozen salmon at your local fishmonger's, ask if it can be ordered for you. Frozen salmon may also be ordered on-line. Just enter "Frozen wild salmon" into your Search engine, and you'll find a number of suppliers. While King salmon is often considered the best tasting salmon and also has the highest levels of omega-3 fatty acids, Coho salmon is also very good.
Canned Salmon Another way to add wild salmon to your menu is to purchase canned salmon, which is available year round and is much less expensive than fresh or frozen salmon. Most all canned salmon is wild salmon, and this is indicated on the label. Canned salmon offers some additional advantages as well. It is usually packed in its own oil, so you can benefit from greater quantities of omega-3s.
Smoked Salmon Smoked wild salmon is also available year round, but because the smoking process reduces its omega-3 content by 75% and also deposits carcinogenic compounds on the salmon, it is not recommended to eat smoked salmon often.
Lox Although only very lightly smoked, this type of prepared salmon contains large quantities of preservatives including sodium nitrate. Since frequent consumption of sodium nitrate has been linked to colon cancer, it is not recommended to eat lox often.
Stokstad, E. Salmon survey stokes debate about farmed fish. Science, vol 303, p154-5, January 9, 2004.