I moved to Vancouver Island a couple of years ago, but I fished here 50
years ago, and I can tell you that, in this part of the world at least, wild
salmon numbers are diminishing very rapidly. 

I understand that one of the causes of this decline is that farmed salmon
have developed some parasites that also attach to wild salmon. The farmed
fish are harvested early enough that the parasites apparently have little
impact on the profits of the salmon farms, but the wild salmon are affected
in several ways - all negative. 

Further, the extensive commercial fishing that has taken place in this area
has also taken its toll. 

Finally, the rivers and creeks in which these fish spawn have been damaged
by dams, pollution, mining, and clear cut logging. All of these practices
are reducing available spawning grounds. The net result is that wild salmon
are dramatically reduced in this area. 

Some government bureaucrats have subsidized salmon farms, approved dams,
permitted pollution, encouraged mining, and turned a blind eye to the
environmental impact and economic short-sightedness of clear-cut logging.  I
can't imagine how these people call themselves public servants, and our
elected representatives seem to be better at representing their own
interests than those of the people who elected them. 

End Rant. 
Ron