All the speculations of contaminated sea water that some articles have published show maps of how the radiation is spreading, if you read the fine print on the bottom of the chart it says" proposed current patterns " or something similar. All they are doing is trying to make their story as scary as possible.
Just finished a Radiation Safety Officer training seminar a couple days ago, and the head instructor was laughing at all the stories about the Japan melt down. He was Canada's leading nuclear inspector till he went private, he said only 3 or 4 people were actually hurt during this whole event over two years. And two of them was because they were walking in radio active water and went over their boots which caused their over exposure.