A study on marine organisms as indicators of radioactive pollution in environmental monitoring

Based on the 'Basic plan for Onagawa Nuclear Power Station to measure environmental radioactivity and hot wastewater,' 'Eisenia bicyclis (arame)' has traditionally been positioned as an indicator marine product to measure radioactivity. However, there were concerns that a decrease in seaweed would proceed and collection of 'arame' would become difficult in the Oshika Peninsula. In view of this situation, as an alternative sample, 'Sargassum yezoense' was subject to trial collection, radioactivity measurement and concentration coefficient calculation. As a result, its compatibility as an indicator marine product was confirmed, and 'Sargassum yezoense' was positioned as an indicator marine product from FY2019. This action has made it possible to reduce the frequency of collecting 'arame' and maintain an appropriate radioactivity monitoring system. (A.O.)