A far more accurate title for the thread given the article you based it on would be "Overfishing is depleting the ocean's fish stocks".
If you had bothered to read the information I provided, you would be aware that fish meal production has been fairly steady for many years. The increasing use in salmon farming has not meant that more is produced. Instead it has meant that less is used for terrestrial animal feed. A decrease in use in salmon farming would simply mean the meal would be used for terrestrial animal feed again. The fishermen who have depleted the world fish stocks aren't fishing for the salmon feed market and don't care where the catch ends up; they are supplying the protein market and that market will take all they can produce. Blaming the salmon farms is the functional equivalent of blaming you for the environmental pollution and damage caused by the oil sands projects because you use oil in your car.
The only way to preserve the fish stocks is to control the fishermen that are overharvesting. That is what that article you based the thread on states and in spite of your entirely predictable attempt to turn it into an indictment of salmon farms, it is the only rational conclusion that can be arrived at.
While the global production of fishmeal has not risen above 7 million tonnes since 1995, it has fluctuated between 5 ans 7 million tonnes since then:
Since then "aquaculture's share of global fishmeal and fish oil consumption more than doubled over the past decade to 68% and 88%, respectively"
1Since those pig farmers you mention still need to feed their livestock, they will put increased pressure on the market and drive prices up further, encouraging even more over fishing. While your analogy of blaming AF for the damage caused by the oil sands is a good one, until we DO blame ourselves for consuming these globally damaging products, we will continue to have people arguing that they should be allowed to continue damaging the environment because "the consumer wills it." I have lived within walking distance of my workplace so that I can walk to work instead of drive. This means I rent as I cannot afford to buy in the neighbourhood, but it is what I can do for the environment. I use those carbon credits for my weekly trips to the flow in my fuel efficient Honda civic. You have to do what you can to stop the rampant destruction of the environment in the name of the consumer.
STOP BUYING FARMED SALMON!!
1. Naylor et al., "Feeding aquaculture in an era of finite resources,"
PNAS September 8, 2009, vol. 106, no. 36, pp. 15103–15110