I went back and googled transgenic salmon and got a bunch of stories from a year ago. Evidently this particular salmon story first came to light because some researchers at Duke wrote a paper and got it in Science. It's from Nov 19, 2010:
http://www.sciencedaily.com/releases/2010/11/101118141539.htm
Frontline/Nova ran a program on this subject. As corporate shills their documentary begins with a both sides to any subject. The program opens with a eco-terrorist group who burned down some biologist's lab in Uni Michigan that was doing research back in the 90s
http://www.youtube.com/watch?v=6NsI0ba9dNg
I am almost finished with it. If you haven't followed this issue, and can stand corporate propaganda, its worth watching. It does cover the some of the basic science. To hear the salmon story and its potential to make the whole species extinct, you have to get to about 10/12. The problem is the giant faster growing males are choose as the preferred mate by female salmon. It turns out that the transgenic male produces fewer offspring who are the weakest survivers. It's the reverse of best. They are the worse mates to select. The consequence is enormous as this spreads across all the salmon in the ocean.
The corporate answer is to sell only sterile female eggs for stocking ocean penned farmers. As the scientist who modelled the outcome of a few transgenic males noted, it still only takes a few of these transgenic males to get into the environment to produce the same disaster. As with industries, mistakes happen and with more farms of transgenic fish grow, so does the probability some male eggs will get through and will get to the open ocean.
There is a simliar risk to all the transgenic fish which are planned for third world markets like Thailand.
In the Frontline/Nova program notice that safety concerns are dismissed by comparing genetic engineered products with first generations of aircraft and other technologies that seem to turn out to be worth the risk. The one technology that is never used in these comparison is the nuclear power industry or the carbon fuel industries which have caused vast amounts of damage to the environment and people, not to mention the biosphere.
CG