Impact on the marine environment of radioactive releases resulting from the Fukushima-Daiichi nuclear accident. May 13, 2011

This information note updates and supplements the previous note of 4 April on the same subject. It describes the origins of the contamination of the marine environment (Direct releases into the sea close to the damaged reactors, atmospheric fall-out onto the surface of the sea, transport of radioactive pollution by leaching of contaminated soil). Then, while proposing several maps, the authors analyse and comment the dispersion in the sea of radioactive pollutants: ocean currents off the Japanese coasts, charts showing the distribution of caesium 137 in seawater, and results of simulations of dispersion. The report briefly discusses the impact of radioactive pollution on living species: concentrations observed in fish, expected concentrations based on the seawater measurements. Finally, it briefly discusses the presence of radionuclides in sediments