If you haven't already, I'd check out Chris Kresser's stance on the issue. Take a look at the comments as well; there are a lot of good points being tossed back and forth, with supporting references.
Fukushima Radiation: Is It Still Safe To Eat Fish?
Personally, I am limiting intake from the Pacific until more long-term research is done. I live close to the Atlantic, where the water may be a bit cleaner (for now).