The following article link is a a really good one and I think that anyone who has eaten or is considering eating farmed fish should reconsider, and not buy it.
The health problems with eating farmed salmon started in 2004 with a Science article Jan 9, 2004 by the Hites group from Albany University. The fish farm industry literally went after the group to neutralize the article. I read the Spinwatch article on what they did and it was the beginning of my not believing anything a fish farm company says without ground proofing it myself. Look in the index for this site in October 2014. It will lead you to the Hites article and the Spinwatch piece by David Miller, UK.
The Hites group has published several articles in the past ten years on the organic and cancer-causing chemicals in farmed salmon.
In 2014, Norwegian scientists and doctors warned Norwegians not to eat farmed salmon, particularly women and children.
Go read for yourself: http://worldtruth.tv/norwegian-scientists-warn-against-eating-farmed-salmon-everything-you-need-to-know-about-farmed-fish/.
Despite this, Stephen Harper, Justin Trudeau and Thomas Mulcair will not take fish farms out of the ocean and put them on land. Elizabeth May will take fish farms out of the water.