Dozens, maybe thousands of european salmon farming small companies vanished about 15 years ago and dumping was the final nail in the coffin. I could tell you some histories that producers said to me, but all is a little more complex than that. In the last 10 years we have a big recession in Europe by the scam. You can not expect a lot of regrowth inside Europe.
We have also two big and destructive tsunamis: Indonesia 2005 and Japan 2011. Ironically the banda-aceh tsunami that wipped entire villages favoured a vigorous regrowth of the aquaculture sector from India to Philipines because: 1-the fisher float was distroyed and 2-survivors were mortally afraid of working at the ocean. The sector in Japan have enough economical muscle to survive practically unscathed to the 2011 disaster. Another consequence was a renewed interest of the investors in South-America; and of course China is growing at at impressive "bigger-better-faster" pace that the rest of the world, as always. Aquaculture of trout and salmon in the south of europe is currently frozen and probably will never recover