Arnie Gundersen, Chief Engineer at Fairewinds Energy Education, World Uranium Symposium — Fukushima Workshop, April 2015 (emphasis added):

• At 7:30 in — Last week, Woods Hole announced a study that showed that about… 7 becquerels per cubic meter [has reached the west coast of North America].
• They called it ‘trace amounts’. I don’t call 7 Bq/m^3 a ‘trace amount’… that’s significant and measurable, and it’s just the beginning of the onslaught.
• There was a study in 2012 that predicted how much radiation was going to get to the west coast of B.C. … [It] was 29 times lower than what [Woods Hole] actually measured.
• So scientists have no clue how to measure what’s transporting through the ocean. Studies two years ago are already wrong by essentially a factor of 30.
• The scientists’… real goal was to downplay the significance of the damage to the Pacific Ocean. It is in fact 29 times worse than predicted.

Woods Hole scientist Ken Buesseler, Apr 24, 2015: “The bad news is, the Japanese found, through their own monitoring data, cesium levels weren’t going down in fish. That means they’re getting a source-they’re getting fed more cesium. There are still leaks at the site… There are 300 tons coming out a day… It’s maintaining levels that are high enough to keep fisheries closed… My latest concern is shifting, as the exposure for cesium has gone done [sic] 10,000 times, but it has stayed pretty constant for strontium-90… The U.S. government has failed us because they don’t analyze ocean waters for radioactivity… It’s crazy… Some say we shouldn’t have cesium in the fish, but there’s already cesium in the fish [he says while laughing]… Don’t worry about the cesium.”

Deutsche Welle, Apr 9, 2015: Scientists have detected radiation… off the Canadian coast. Experts disagree as to whether the amount detected constitutes a dangerous level or not… [According to scientist Peer van de Rijk]… “There is only one safe level: that is zero level. Every amount is possibly harmful, and it adds up. You can never say that there is a safe dose for radiation.” If cesium-134 and cesium-137 accumulate in the body, this can damage cell structures… radiation is also likely to be measured in other parts of the globe… “Radiation travels with the wind and the ocean. And it’s very possible that it will show up everywhere else in the coming years,” van de Rijk adds.

Watch Gundersen’s presentation here