by Staff Writers
Washington (AFP) May 29, 2012
Bluefin tuna caught off the US coast have been found to contain radioactive material from Japan's quake-struck Fukushima nuclear plant, according to a new study.
Researchers found "modestly elevated levels" of two radioactive isotopes in 15 bluefin tuna caught off the coast of San Diego, California in August 2011, according to the study published online Monday by the Proceedings of the National Academy of Sciences (PNAS).
The researchers said the elevated radioactivity posed no risk to public health as the observed levels were more than an order of magnitude lower than the Japanese safety limit and were lower than other naturally present isotopes.
"We were quite surprised to find that bluefin carried both of these isotopes," co-author Nicholas Fisher, of New York's Stony Brook University, told CNN on Tuesday.
The study found slightly higher levels of radioactive cesium-134 and cesium-137 in the 15 tuna, compared to bluefin tuna caught in the same area before the Fukushima nuclear disaster and to yellowfin tuna -- which keep to the eastern Pacific -- caught before or after the accident.
The study said the results provide "unequivocal evidence" that the fish had carried Fukushima-derived radioactive material across the ocean over the course of their easterly migration.
"These findings indicate that Pacific bluefin tuna can rapidly transport radionuclides from a point source in Japan to distant ecoregions and demonstrate the importance of migratory animals as transport vectors," it said.
The researchers emphasized that the level of cesium isotopes detected would not endanger public health, especially as they give off far less radiation than potassium-40, a naturally-present isotope found in all the fish.
"I personally would not hesitate to eat the tuna that were caught off the coast of California," Fisher said.
The massive 9.0-magnitude earthquake and tsunami on March 11, 2011 killed thousands of people and crippled the cooling systems at the Fukushima plant, causing meltdowns in several of its reactors.
Radiation leaked into the air, soil and sea around the plant, forcing tens of thousands of people to evacuate their homes.
Water News - Science, Technology and Politics
Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.
Deep sea animals stowaway on submarines and reach new territory
Chicago IL (SPX) May 28, 2012
Marine scientists studying life around deep-sea vents have discovered that some hardy species can survive the extreme change in pressure that occurs when a research submersible rises to the surface. The team's findings, published in Conservation Biology, reveal how a species can be inadvertently carried by submersibles to new areas, with potentially damaging effects on marine ecosystems. ... read more
|The content herein, unless otherwise known to be public domain, are Copyright 1995-2012 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement|