Inter-tissue differences and temporal trends in ¹³⁷Cs activities of a brown alga arame, following the Fukushima Daiichi Nuclear Power Plant accident

Inter-tissue differences in ¹³⁷Cs activities of a brown alga, arame (Eisenia bicyclis) and also temporal trends of the ¹³⁷Cs activities in the laminae were investigated in Miyagi Pref., Japan, following the Fukushima Daiichi Nuclear Power Plant Accident on March 11, 2011. In the western and northern areas of the Oshika peninsula in August and November 2012, remarkable inter-tissue differences in ¹³⁷Cs activities in arame were observed. The ¹³⁷Cs activities in the stipes of the arame were an order of magnitude higher than those in the laminae. On the contrary, there was not much difference between stipes and laminae in ⁴⁰K . No clear seasonal fluctuations in ¹³⁷Cs activity of laminae of arame were found in the early 2011 to 2017, although seasonal fluctuations were observed in ⁴⁰K . Thus, useful findings for environmental radioactivity monitoring using marine organisms as a bioindicator were obtained. (author)