With respect. Your description of the triploid process is somewhat inaccurate. When the egg is fertilised the germ cell from the egg divides into two polar bodies each containing a set of chromosomes. The sperm will combine with one of the female sets of chromosomes to form the first cell - having two sets of chromosomes one from each parent, hence the term diploid. The mechanism which drives away the second polar body from the union with the sperm can be interrupted to retain the chromosomes. This process allows all three sets to combine and form the first cell, hence the term triploid. Just to add, triploidy in salmonids occurs naturally albeit at a low frequency - one in 5-10,000. By harnessing this natural trait for sterility we can protect our wild fish stocks, grow larger fish more efficiently and provide good quarry for sports anglers.
It's true that triploids won't reproduce in the wild, but male salmon will in fact disturb the mating season for wild salmon, while females won't. I wonder if these guys know that.
In UK we only stock all-female triploid salmonids as male triploids display all the characteristics of fertile males but are nonetheless sterile. This means they may well try to spawn with a wild female and prevent her contribution to the next generation. A very dangerous event in progressive genetic adaptation and a reduction in overall wild recruitment.
