Gnu, that blog or whatever you want to call it is one of those scare the hell out of them exaggerations from anti-GMO anti-everything
nutcakes.

Go to the U.S. FDA, or the Canadian equivalent.
http://www.fda.gov/ucm/groups/fdagov-publin/@fdagov-foods-gen/docurr
(or just google "acceptable radiation levels, Pacific fish" and look for a government release.

The radiation is slowly spreading from the Fukushima site, but is nowhere near unacceptable limits in fish sold in North America. It has not reached major N. Am. fisheries. The data at the site linked is 2 years old, but more up-to-date articles can be found, and show little difference.
See 2013 article in sciencedaily.com on Fukushima radiation "poses minimal threat"; google "Fukushima-derived radiation in seafood poses minimal health risk, experts say."

That there is a possible threat in the future is real; but FDA, etc., will keep track of the situation.