Decline in intertidal biota after the 2011 Great East Japan Earthquake and Tsunami and the Fukushima nuclear disaster: field observations.

Toshihiro Horiguchi,Hiroaki Shiraishi,Satoshi Mizuno,Hiroshi Yoshii

doi:10.1038/srep20416

Toshihiro Horiguchi, Hiroaki Shiraishi + Show 2 more

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https://doi.org/10.1038/srep20416

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Abstract

In 2011, 2012, and 2013, in the intertidal zones of eastern Japan, we investigated the ecological effects of the severe accident at the Fukushima Daiichi Nuclear Power Plant that accompanied the 2011 Great East Japan Earthquake and Tsunami. The number of intertidal species decreased significantly with decreasing distance from the power plant, and no rock shell (Thais clavigera) specimens were collected near the plant, from Hirono to Futaba Beach (a distance of approximately 30 km) in 2012. The collection of rock shell specimens at many other sites hit by the tsunami suggests that the absence of rock shells around the plant in 2012 might have been caused by the nuclear accident in 2011. Quantitative surveys in 2013 showed that the number of species and population densities in the intertidal zones were much lower at sites near, or within several kilometers south of, the plant than at other sites and lower than in 1995, especially in the case of Arthropoda. There is no clear explanation for these findings, but it is evident that the intertidal biota around the power plant has been affected since the nuclear accident.

Highlights

In 2011, 2012, and 2013, in the intertidal zones of eastern Japan, we investigated the ecological effects of the severe accident at the Fukushima Daiichi Nuclear Power Plant that accompanied the 2011 Great East Japan Earthquake and Tsunami
There is no clear explanation for these findings, but it is evident that the intertidal biota around the power plant has been affected since the nuclear accident
No rock shell (Thais clavigera) specimens were collected at eight sites near Fukushima Daiichi Nuclear Power Plant (FDNPP) in Fukushima Prefecture in 2012

Summary

Introduction

In 2011, 2012, and 2013, in the intertidal zones of eastern Japan, we investigated the ecological effects of the severe accident at the Fukushima Daiichi Nuclear Power Plant that accompanied the 2011 Great East Japan Earthquake and Tsunami. The Fukushima nuclear disaster released almost the same amount of 137Cs as the maximum annual emission from the Sellafield plants (5.2 PBq) into the coastal waters of Fukushima over a relatively short period (from mid-March to early May 2011)[4], suggesting that the marine organisms around FDNPP, unlike those around Sellafield, might have experienced acute or sub-acute, rather than chronic, exposure to 137Cs and other radionuclides. An analysis of calculated dose rates in Fukushima’s most affected areas indicated that more severe impacts were likely in the coastal ecosystem adjacent to FDNPP than in forest ecosystems[11] It is unknown whether any harmful chemicals leaked into the sea along with the various radionuclides, leakage of boric acid and hydrazine was possible[12,13]

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