These tuna make this circuit each year. Some of the same fish will feed and grow and make the same second circuit next year - except they will consume and concentrate more cesium from the fish they feed on while near Japan. Since cesium's half life is 30 years then this problem is going to be around for a few human generations. The article doesn't detail other dangerous radioactive isotopes that might also be present from Fukushima's nuclear plants - and their nuclear plant designs that chose to ignore the area's earth quakes and tsunami risks. "The Fukushima accident has led to trace amounts of radiation, including iodine-131, caesium-134 and caesium-137, being observed around the world (New York State, Alaska, Hawaii, Oregon, California, Montreal, and Austria).[352][353][354] Large amounts of radioactive isotopes have also been released into the Pacific Ocean." (
http://www.smartplanet.com/blog/intelligent-energy/radioactive-tuna-found-off-californian-coast/16378?tag=nl.e660)
