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Pacific bluefin tuna which have migrated from Japan to Californiahave been found to be contaminated with radioactive cesium from theFukushima nuclear accident, researchers from Stanford's HopkinsMarine Station in Pacific have reported in PNAS (Proceedings of theNational Academy of Sciences) . Despite radiation contamination, levels so far detected are wellbelow those considered hazardous for human health, the authorsemphasized. The researchers have no doubt that the fish caught of the San Diegocoast in 2011 were contaminated with radiation that originated fromthe nuclear disaster. Seafood distributors have been assuring the American public thattheir bluefin tuna should not be affected by radiation because theyare fished thousands of miles from Japanese waters. Bluefin tuna migrate, and on this occasion were caught by sportsfishermen off the Californian coast. Daniel J. Madigan, a marineecologist, senior author in this study, added that the affectedtuna had not been headed for the consumer market in the USA. Pacific bluefin tuna Contaminated tuna, a surprise discovery Madigan explained that he and his colleagues had been studyingbluefin tina migratory patterns; fish radiation levels had not beenthe aim of their overall Pacific fish migration study. San Diego had given them muscle samples from 15 fishes, average age2 years, by sports fishermen in August last year. Routine testsdetected radioactivity in one of the samples. All samples weresubsequently sent to Nicolas Fisher at Stony Brook University onLong Island for further testing. Fisher is a radiation hazardsexperts of international repute. The tuna were found to be contaminated with radioactive cesium; twoforms: Cesium-134 isotope Cesium-137 isotope These two isotopes are only produced in nuclear explosions, and donot exist naturally. Cesium-137 takes thousands of years to break down, while Cesium-134is shorter-lived. Madigan said that radiation contamination, if it is also present inother migratory sea animals, such as sharks, turtles, and evenbirds and seals, acts as a tracer and helps researchers bettertrack their migratory patterns. New group of bluefin tuna to be studied soon Madigan and team say they are about to collect samples from anothergroup of bluefin tuna that has migrated to Californian watersrecently. Their aim is specifically to find out whether thesefishes are also contaminated with radioactive cesium. The tuna in this new group have spent a year longer off theJapanese coast after the nuclear accident. The scientists want tofind out whether their radiation levels have dropped or increased. Fisher said: "We don't think there will be any public health concern from theresults of the new tests, but if we do see any higherconcentrations of cesium, we will certainly alert public healthagencies again." Written by Christian Nordqvist Copyright: Medical News Today Not to be reproduced without permission of Medical News Today Additional References Citations. The e-commerce company in China offers quality products such as AVL GPS System Manufacturer , GPS GSM Personal Tracker, and more. For more , please visit SD Card GPS Receiver today!
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