Radioactive cesium up to 100 times pre-nuclear disaster levels has been detected in plankton inhabiting the sea far from the crippled nuclear plant following the March 2011 disaster, according to a survey conducted by Japanese and U.S. researchers.The high concentration of cesium, which is believed to derive from the Fukushima No. 1 Nuclear Power Plant, suggests that radioactive substances that have leaked from the complex are spreading extensively in the sea.
Jun Nishikawa, research associate with the University of Tokyo's Atmosphere and Ocean Research Institute, underscored the need for a long-term survey on the contamination of marine creatures with radioactive substances.
"Even though radiation levels detected from the plankton samples were still low, there is a possibility that large amounts of cesium will accumulate in fish through the food chain in a phenomenon called biological concentration. We need to continue our survey," he said. "Each species of marine creatures that feed on animal plankton need to be monitored over the long term."
The results of the survey were published in the Proceedings of the National Academy of Sciences of the United States on April 3. Read More
