Fish need all the breaks they can get, with the Japanese dumping billions of pounds of Fukushima rad-waste into the ocean  (& no end to thatin sight); ocean acidification from uncontrolled carbon emissions, which creates carbolic acid to the detriment of crustacean shells and the base of the salmon pyramid, krill, and increasing harvests by offshore fisheries, which intercept fish before they ever reach the Elwha. 
Continued use of coal for power means all fish has mercury in it, and the farther up the chain, the more it concentrates, so sardines are healthier to eat than salmon (but beware of BPA from the lining of cans they're cooked in.) At least salmon aren't bottom-feeders like halibut, but are any fish safe to eat anymore? Gov't response is simply to raise allowable limits of radioactivity and pollutants in our food. Eat lots of cilantro and garlic to detox, and enjoy what time we have left. 
http://www.globalpossibilities.org/earths-sixth-mass-extinction-already-underway/