Go back and look at my post that summarizes the 101 on-land fish farm systems, now comprising more than 10,000 actual, on land systems around the world: http://fishfarmnews.blogspot.ca/2012/01/key-document-34-mostly-on-land-closed.html.
There is no need anymore for the dinosaur, old-tech Norwegian-style in-ocean fish farms that use the world's oceans as free, open sewers. If you hear a fish farm making the claim they have to be in the public's oceans, tell them it just isn't so, and they need to get out of our oceans, contain their sewage, eliminate lice problems and chemicals, avoid killing sea lions and sea birds, avoid killing wild salmon and get with the rest of the world.
Marine Harvest operates in 22 countries - dumping their raw sewage right from their cages - and along with Cermaq and Grieg Seafood need to be chastised until they come out of the ocean. Don't buy farmed fish if you don't want our oceans polluted by companies that, collectively, put out more sewage than the entire human populations of many of the countries they operate in. This includes Norway itself, Scotland and BC Canada.
Note that you should also boycott Mitsubishi products, including their cars, because it bought Cermaq earlier this year.
Also, this just in Aug 20, 2015: AKVA on-land fish farms systems (a Norwegian company) is having its highest growth ever, even in Norway. See: http://www.undercurrentnews.com/2015/08/20/akva-seeing-historically-high-interest-in-land-based-farming-amid-record-quarter-h1/?utm_source=Undercurrent+News+Alerts&utm_campaign=d35cf2dd4c-Europe_briefing_Aug_20_2015&utm_medium=email&utm_term=0_feb55e2e23-d35cf2dd4c-92426209.