Seasonal variation of Cesium-137 concentration in Asian black bear (Ursus thibetanus) and wild boar (Sus scrofa) in Fukushima Prefecture, Japan.

To elucidate and reduce the risk of radionuclide contamination in wildlife caused by the Tokyo Electric Power Company Fukushima Dai-ichi Nuclear Power Station accident, it is important to understand radionuclide variations in the wild animal population. Here, we used environmental monitoring data an...

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Main Authors: Yui Nemoto, Rie Saito, Hitoshi Oomachi
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2018-01-01
Series:PLoS ONE
Online Access:http://europepmc.org/articles/PMC6051634?pdf=render
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author Yui Nemoto
Rie Saito
Hitoshi Oomachi
author_facet Yui Nemoto
Rie Saito
Hitoshi Oomachi
author_sort Yui Nemoto
collection DOAJ
description To elucidate and reduce the risk of radionuclide contamination in wildlife caused by the Tokyo Electric Power Company Fukushima Dai-ichi Nuclear Power Station accident, it is important to understand radionuclide variations in the wild animal population. Here, we used environmental monitoring data and muscle samples collected from Asian black bear (Ursus thibetanus) and wild boar (Sus scrofa) from May 2011 to March 2016 to examine seasonal variation in radiocesium (137Cs) concentrations in muscle tissues (hereafter, muscle 137Cs) of these important game species in Fukushima Prefecture. We measured muscle 137Cs of bears and wild boars killed by hunters or in animal control culls. First, using a linear mixed model (LMM), we tested for a positive relationship between muscle 137Cs and 137Cs in the soil at the site of capture (hereafter, soil 137Cs) estimated from a soil 137Cs deposition map produced by the Japan Atomic Energy Agency. In the LMM, muscle 137Cs was positively related to estimated soil 137Cs, which corroborates the results of previous studies. The LMM regression coefficients differed between the two species, with wild boar muscle 137Cs being higher than that of bears sampled at the same locations. We then employed a generalized additive mixed model (GAMM) to estimate seasonal variation in the muscle 137Cs of the target species. GAMM showed that muscle 137Cs varied seasonally and that this seasonal variation also differed between the two species. In bears, muscle 137Cs decreased from spring to early autumn, before increasing in winter. Wild boar muscle 137Cs remained low during spring and summer and was high during autumn and early spring. These patterns are likely influenced by differences in diet, habitat use, and physiology between these two species.
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spelling doaj.art-c77654c50383482fbb55abf393de4d922022-12-22T02:00:13ZengPublic Library of Science (PLoS)PLoS ONE1932-62032018-01-01137e020079710.1371/journal.pone.0200797Seasonal variation of Cesium-137 concentration in Asian black bear (Ursus thibetanus) and wild boar (Sus scrofa) in Fukushima Prefecture, Japan.Yui NemotoRie SaitoHitoshi OomachiTo elucidate and reduce the risk of radionuclide contamination in wildlife caused by the Tokyo Electric Power Company Fukushima Dai-ichi Nuclear Power Station accident, it is important to understand radionuclide variations in the wild animal population. Here, we used environmental monitoring data and muscle samples collected from Asian black bear (Ursus thibetanus) and wild boar (Sus scrofa) from May 2011 to March 2016 to examine seasonal variation in radiocesium (137Cs) concentrations in muscle tissues (hereafter, muscle 137Cs) of these important game species in Fukushima Prefecture. We measured muscle 137Cs of bears and wild boars killed by hunters or in animal control culls. First, using a linear mixed model (LMM), we tested for a positive relationship between muscle 137Cs and 137Cs in the soil at the site of capture (hereafter, soil 137Cs) estimated from a soil 137Cs deposition map produced by the Japan Atomic Energy Agency. In the LMM, muscle 137Cs was positively related to estimated soil 137Cs, which corroborates the results of previous studies. The LMM regression coefficients differed between the two species, with wild boar muscle 137Cs being higher than that of bears sampled at the same locations. We then employed a generalized additive mixed model (GAMM) to estimate seasonal variation in the muscle 137Cs of the target species. GAMM showed that muscle 137Cs varied seasonally and that this seasonal variation also differed between the two species. In bears, muscle 137Cs decreased from spring to early autumn, before increasing in winter. Wild boar muscle 137Cs remained low during spring and summer and was high during autumn and early spring. These patterns are likely influenced by differences in diet, habitat use, and physiology between these two species.http://europepmc.org/articles/PMC6051634?pdf=render
spellingShingle Yui Nemoto
Rie Saito
Hitoshi Oomachi
Seasonal variation of Cesium-137 concentration in Asian black bear (Ursus thibetanus) and wild boar (Sus scrofa) in Fukushima Prefecture, Japan.
PLoS ONE
title Seasonal variation of Cesium-137 concentration in Asian black bear (Ursus thibetanus) and wild boar (Sus scrofa) in Fukushima Prefecture, Japan.
title_full Seasonal variation of Cesium-137 concentration in Asian black bear (Ursus thibetanus) and wild boar (Sus scrofa) in Fukushima Prefecture, Japan.
title_fullStr Seasonal variation of Cesium-137 concentration in Asian black bear (Ursus thibetanus) and wild boar (Sus scrofa) in Fukushima Prefecture, Japan.
title_full_unstemmed Seasonal variation of Cesium-137 concentration in Asian black bear (Ursus thibetanus) and wild boar (Sus scrofa) in Fukushima Prefecture, Japan.
title_short Seasonal variation of Cesium-137 concentration in Asian black bear (Ursus thibetanus) and wild boar (Sus scrofa) in Fukushima Prefecture, Japan.
title_sort seasonal variation of cesium 137 concentration in asian black bear ursus thibetanus and wild boar sus scrofa in fukushima prefecture japan
url http://europepmc.org/articles/PMC6051634?pdf=render
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AT riesaito seasonalvariationofcesium137concentrationinasianblackbearursusthibetanusandwildboarsusscrofainfukushimaprefecturejapan
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