Keywords: 
• ¹³⁷Cs /
• marine organisms /
• enrichment /
• ecological risk

Abstract: ¹³⁷Cs is one of the main artificial radionuclides and important indicators in the monitoring of radioactive liquid effluent of the coastal nuclear power plants. It is easily accumulated by marine organisms, and the enrichment status of radioactive cesium by marine biota in the surrounding sea areas of nuclear power plants has attracted much attention. After analysis of the manners of radioactive ¹³⁷Cs enrichment by marine organisms, the population characteristics of bioconcentration coefficient and the radiation dose rate of artificial radionuclides in marine organisms, the results show that 1) the radioactivity level of ¹³⁷Cs in seawater near the coastal nuclear power plant is rather low; 2) the population characteristics is not significant in bioconcentration coefficient; 3) the organisms with higher enrichment level of radioactive cesium mainly belong to benthic species; 4) the enrichment levels of marine organisms near the coastal nuclear power plants are usually lower than the threshold of radiation dose rate that can cause ionizing radiation damage. With the great development of coastal nuclear power plants in China, it is necessary to pay more attention to the indicator organism selection, biological quality safety in radioactivity monitoring and ecological health risks assessment of environmental radioactivity.