Observation of Radionuclides in Marine Biota off the Coast of Fukushima Prefecture After TEPCO’s Fukushima Daiichi Nuclear Power Station Accident

Monitoring and surveying of radioactivity in seawater and biota in the marine environment off the coast of Fukushima Prefecture in the Pacific Ocean are important for understanding the dispersion of artificial radionuclides after the TEPCO Fukushima Daiichi Nuclear Power Station (FD1NPS) accident. Marine biota were collected in the coastal area off Fukushima Prefecture after this accident to investigate the radioactivity of 134Cs, 137Cs, and 110mAg in marine biota, including not only fish and shellfish but also benthos. It is well known that 108mAg, one of the radioactive isotopes of Ag, was observed in some kinds of squid and octopus before this accident. As a result, 110mAg was observed in many kinds of marine biota off the coastal area of Fukushima. It is suggested that rapid change in the radioactivity in seawater, resuspension of particles from sediments, and food chain effects led to high radionuclide activities in the marine biota after this accident.