title: Fukushima-derived radionuclides in the ocean and biota off Japan.
abstract: The Tōhoku earthquake and tsunami of March 11, 2011, resulted in unprecedented radioactivity releases from the Fukushima Dai-ichi nuclear power plants to the Northwest Pacific Ocean. Results are presented here from an international study of radionuclide contaminants in surface and subsurface waters, as well as in zooplankton and fish, off Japan in June 2011. A major finding is detection of Fukushima-derived (134)Cs and (137)Cs throughout waters 30-600 km offshore, with the highest activities associated with near-shore eddies and the Kuroshio Current acting as a southern boundary for transport. Fukushima-derived Cs isotopes were also detected in zooplankton and mesopelagic fish, and unique to this study we also find (110 m)Ag in zooplankton. Vertical profiles are used to calculate a total inventory of ~2 PBq (137)Cs in an ocean area of 150,000 km(2). Our results can only be understood in the context of our drifter data and an oceanographic model that shows rapid advection of contaminants further out in the Pacific. Importantly, our data are consistent with higher estimates of the magnitude of Fukushima fallout and direct releases [Stohl et al. (2011) Atmos Chem Phys Discuss 11:28319-28394; Bailly du Bois et al. (2011) J Environ Radioact, 10.1016/j.jenvrad.2011.11.015]. We address risks to public health and marine biota by showing that though Cs isotopes are elevated 10-1,000× over prior levels in waters off Japan, radiation risks due to these radionuclides are below those generally considered harmful to marine animals and human consumers, and even below those from naturally occurring radionuclides.
authors.affiliation: Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA. kbuesseler@whoi.edu
authors.forename: Ken O
authors.initials: KO
authors.lastname: Buesseler
authors.forename: Steven R
authors.initials: SR
authors.lastname: Jayne
authors.forename: Nicholas S
authors.initials: NS
authors.lastname: Fisher
authors.forename: Irina I
authors.initials: II
authors.lastname: Rypina
authors.forename: Hannes
authors.initials: H
authors.lastname: Baumann
authors.forename: Zofia
authors.initials: Z
authors.lastname: Baumann
authors.forename: Crystaline F
authors.initials: CF
authors.lastname: Breier
authors.forename: Elizabeth M
authors.initials: EM
authors.lastname: Douglass
authors.forename: Jennifer
authors.initials: J
authors.lastname: George
authors.forename: Alison M
authors.initials: AM
authors.lastname: Macdonald
authors.forename: Hiroomi
authors.initials: H
authors.lastname: Miyamoto
authors.forename: Jun
authors.initials: J
authors.lastname: Nishikawa
authors.forename: Steven M
authors.initials: SM
authors.lastname: Pike
authors.forename: Sashiko
authors.initials: S
authors.lastname: Yoshida
mesh_terms: D000818:Animals; D058448:Biota; D002588:Cesium Radioisotopes / Q000032:analysis; D004190:Disasters; D055866:Earthquakes; D005399:Fishes / Q000378:metabolism; D006801:Humans; D007564:Japan; D010140:Pacific Ocean; D011834:Radiation Monitoring / Q000706:statistics & numerical data; D011847:Radioactive Fallout / Q000706:statistics & numerical data*; D018788:Radioactive Hazard Release / Q000706:statistics & numerical data; D011868:Radioisotopes / Q000032:analysis*; D057192:Tsunamis; D014875:Water Pollutants, Radioactive / Q000032:analysis*; D015048:Zooplankton / Q000378:metabolism
chemical_list: D002588:Cesium Radioisotopes; D011847:Radioactive Fallout; D011868:Radioisotopes; D014875:Water Pollutants, Radioactive