http://deepseanews.com/2013/11/true-facts-about-ocean-radiation-and-the-fukushima-disaster/
Always look for the information source that isn't screaming "ZOMFG THE SKY IS FALLING!"
Basically, it says the graphics going around the web are a bunch of baloney, the end result for most of the Pacific will be less than Chernobyl was for the Black Sea, and that only bottom-dwelling marine life in the immediate area of Fukushima is that badly hit.