The AP’s science writer Alicia Chan indicates that ‘[a]cross the vast Pacific, the mighty bluefin tuna carried radioactive contamination that leaked from Japan’s crippled nuclear plant to the shores of the United States 6,000 miles away — the first time a huge migrating fish has been shown to carry radioactivity such a distance. “We were frankly kind of startled,” said Nicholas Fisher, one of the researchers reporting the findings online Monday [, 28 May] in the Proceedings of the National Academy of Sciences. The levels of radioactive cesium were 10 times higher than the amount measured in tuna off the California coast in previous years. But even so, that’s still far below safe-to-eat limits set by the U.S. and Japanese governments. Previously, smaller fish and plankton were found with elevated levels of radiation in Japanese waters after a magnitude-9 earthquake in March 2011 triggered a tsunami that badly damaged the Fukushima Dai-ichi reactors. But scientists did not expect the nuclear fallout to linger in huge fish that sail the world because such fish can metabolize and shed radioactive substances. One of the largest and speediest fish, Pacific bluefin tuna can grow to 10 feet and weigh more than 1,000 pounds. They spawn off the Japan coast and swim east at breakneck speed to school in waters off California and the tip of Baja California, Mexico. Five months after the Fukushima disaster, Fisher of Stony Brook University in New York and a team decided to test Pacific bluefin that were caught off the coast of San Diego. To their surprise, tissue samples from all 15 tuna captured contained levels of two radioactive substances — ceisum-134 and cesium-137 — that were higher than in previous catches. To rule out the possibility that the radiation was carried by ocean currents or deposited in the sea through the atmosphere, the team also analyzed yellowfin tuna, found in the eastern Pacific, and bluefin that migrated to Southern California before the nuclear crisis. They found no trace of cesium-134 and only background levels of cesium-137 left over from nuclear weapons testing in the 1960s’.
And those still in doubt about the dangers posed by the Fukushimadisaster, the Woods Hole Oceanographic Institution’s Ken Buesseler declares that the results “are unequivocal. Fukushimawas the source [of the radioactive contamination]”.
The above-quoted article begins with the clear statement that the “Fukushima Dai-ichi release of radionuclides into ocean waters caused significant local and global concern regarding the spread of radioactive material”, and then adding, “We now report unequivocal evidence that Pacific bluefin tuna, Thunnus orientalis, transported Fukushima-derived radionuclides across the entire North Pacific Ocean. The operative word in this context is clearly “unequivocal” . . . Is this the beginning of a radioactive ocean inhabited by fish and other creatures spreading the good news of contamination wide and far across the world???
 Alicia Chan, “Radioactive bluefin tuna crossed the Pacific to US” AP (28 May 2012). http://www.google.com/hostednews/ap/article/ALeqM5jQLZGd4Qz6APSA3YNA2Wkyi3HGBQ?docId=8aef0b7418e546cb85f6436b3ff6b49e.
 Alicia Chan, “Radioactive bluefin tuna crossed the Pacific to US”.
 D. J. Madigan, Z. Baumann, and N.S. Fisher, “Pacific bluefin tuna transport Fukushima radionuclides from Japan to California” Proceedings of the National Academy of Sciences http://www.pnas.org/content/early/2012/05/22/1204859109.full.pdf+html?sid=d5c8c422-e873-4d05-8062-e3039a2b2617.