title: Spatiotemporal abnormality dynamics of the pale grass blue butterfly: three years of monitoring (2011-2013) after the Fukushima nuclear accident.
abstract: BACKGROUND
  Long-term monitoring of the biological impacts of the radioactive pollution caused by the Fukushima nuclear accident in March 2011 is required to understand what has occurred in organisms living in the polluted areas. Here, we investigated spatial and temporal changes of the abnormality rate (AR) in both field-caught adult populations and laboratory-reared offspring populations of the pale grass blue butterfly, Zizeeria maha, which has generation time of approximately one month. We monitored 7 localities (Fukushima, Motomiya, Hirono, Iwaki, Takahagi, Mito, and Tsukuba) every spring and fall over 3 years (2011-2013).
  
  
  RESULTS
  The adult ARs of these localities quickly increased and peaked in the fall of 2011, which was not observed in non-contaminated localities. In the offspring generation, the total ARs, which include deaths at the larval, prepupal, and pupal stages and morphological abnormalities at the adult stage, peaked either in the fall of 2011 or in the spring of 2012, with much higher levels than those of the parent field populations, suggesting that high incidence of deaths and abnormalities might have occurred in the field populations. Importantly, the elevated ARs of the field and offspring populations settled back to a normal level by the fall of 2012 and by the spring of 2013, respectively. Similar results were obtained not only in the spatiotemporal dynamics of the number of individuals caught per minute but also in the temporal dynamics of the correlation coefficient between the adult abnormality rate and the ground radiation dose or the distance from the Power Plant.
  
  
  CONCLUSIONS
  These results demonstrated an occurrence and an accumulation of adverse physiological and genetic effects in early generations, followed by their decrease and leveling off at a normal level, providing the most comprehensive record of biological dynamics after a nuclear accident available today. This study also indicates the importance of considering generation time and adaptive evolution in evaluating the biological impacts of artificial pollution in wild organisms.
authors.affiliation: The BCPH Unit of Molecular Physiology, Department of Chemistry, Biology and Marine Science, University of the Ryukyus, Okinawa, 903-0213, Japan. atsuki.hiyama@gmail.com.
authors.forename: Atsuki
authors.initials: A
authors.lastname: Hiyama
authors.affiliation: The BCPH Unit of Molecular Physiology, Department of Chemistry, Biology and Marine Science, University of the Ryukyus, Okinawa, 903-0213, Japan. wataira@gmail.com.
authors.forename: Wataru
authors.initials: W
authors.lastname: Taira
authors.affiliation: The BCPH Unit of Molecular Physiology, Department of Chemistry, Biology and Marine Science, University of the Ryukyus, Okinawa, 903-0213, Japan. chiyodon@gmail.com.
authors.forename: Chiyo
authors.initials: C
authors.lastname: Nohara
authors.affiliation: The BCPH Unit of Molecular Physiology, Department of Chemistry, Biology and Marine Science, University of the Ryukyus, Okinawa, 903-0213, Japan. im.05h.nar@gmail.com.
authors.forename: Mayo
authors.initials: M
authors.lastname: Iwasaki
authors.affiliation: The BCPH Unit of Molecular Physiology, Department of Chemistry, Biology and Marine Science, University of the Ryukyus, Okinawa, 903-0213, Japan. enjoy.kingyo@gmail.com.
authors.forename: Seira
authors.initials: S
authors.lastname: Kinjo
authors.affiliation: The BCPH Unit of Molecular Physiology, Department of Chemistry, Biology and Marine Science, University of the Ryukyus, Okinawa, 903-0213, Japan. iwata0805@gmail.com.
authors.forename: Masaki
authors.initials: M
authors.lastname: Iwata
authors.affiliation: The BCPH Unit of Molecular Physiology, Department of Chemistry, Biology and Marine Science, University of the Ryukyus, Okinawa, 903-0213, Japan. otaki@sci.u-ryukyu.ac.jp.
authors.forename: Joji M
authors.initials: JM
authors.lastname: Otaki
mesh_terms: D000818:Animals; D002080:Butterflies / Q000254:growth & development* / Q000528:radiation effects*; D062406:Fukushima Nuclear Accident; D007564:Japan; D007814:Larva / Q000254:growth & development; D011157:Population Dynamics; D011679:Pupa / Q000254:growth & development; D012990:Soil Pollutants, Radioactive / Q000032:analysis
chemical_list: D012990:Soil Pollutants, Radioactive