Published on Tuesday, April 3, 2012 by Common Dreams
Radiation Moving Steadily Across Pacific Fukushima
Concentrated levels found as scientists sample the Pacific for signs of Fukushima
- Common Dreams staff
Teams of scientists have already found debris and levels of radiation far off the coast of
"What this means for the marine environment of the Northwest Pacific over the long term is something that we need to keep our eyes on," said the WHOI.
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Fukushima Radiation Tracked Across Pacific Ocean (Live Science):
"We saw a telephone pole," study leader Ken Buesseler, a marine chemist and oceanographer at WHOI, told LiveScience. "There were lots of chemical plants. A lot of stuff got washed into the ocean."
The Tohoku earthquake and tsunami of March 11, 2011, led to large releases of radioactive elements from the
The drifters are tracked via GPS, showing the direction of currents over a period of about five months. Meanwhile, the team also took samples of zooplankton (tiny floating animals) and fish, measuring the concentration of radioactive cesium in the water.
Small amounts of radioactive cesium-137, which takes about 30 years for half the material to decay (called its half-life), would be expected in the water, largely left over from atmospheric nuclear tests in the 1960s and the
The team also looked at the amounts of cesium isotopes in the local sea life, including zooplankton, copepods (tiny crustaceans), shrimp and fish. They found both cesium-137 and cesium-134 in the animals, sometimes at concentrations hundreds of times that of the surrounding water. Average radioactivity was about 10 to 15 Bq per kilogram, depending on whether it was zooplankton or fish (concentrations were lowest in the fish).
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An international research team is reporting the results of a research cruise they organized to study the amount, spread, and impacts of radiation released into the ocean from the tsunami-crippled reactors in
Led by Ken Buesseler, a senior scientist and marine chemist at the Woods Hole Oceanographic Institution (WHOI), the team found that the concentration of several key radioactive substances, or radionuclides, were elevated but varied widely across the study area, reflecting the complex nature of the marine environment. In addition, although levels of radioactivity in marine life sampled during the cruise were well below levels of concern for humans and the organisms themselves, the researchers leave open the question of whether radioactive materials are accumulating on the seafloor sediments and, if so, whether these might pose a long-term threat to the marine ecosystem. The results appear in the online edition of the journal Proceedings of the National Academy of Sciences (PNAS).
"Our goal was to provide an independent assessment of what the Japanese were reporting and also to get further off shore to sample in places where we thought the currents would be carrying most of the radionuclides," said Buesseler. "We also wanted to provide as wide ranging a look as possible at potential impacts on the marine system to give a better idea of what was going on in the region, but also to provide a stronger baseline from which to measure future changes." [...]
Another open question is why radiation levels in the waters around
"What this means for the marine environment of the Northwest Pacific over the long term is something that we need to keep our eyes on," said Buesseler.
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