[en] The development of marine radioecology research by the China Institute for Radiation Protection (CIRP) is reviewed and recent research described. The focus of the work is on studies of the impact of radioactive effluents discharged from the Guangdong Nuclear Power Plant (GNPP) on the offshore marine ecosystem of Daya Bay both before and after the start of the plant's operation. The results indicate that after the plant started operating the sea water ⁹⁰Sr and ¹³⁷Cs concentrations were similar to background levels. The ¹¹⁰Ag^m concentration in some species of marine organisms was about 1.0 Bq.kg^-1 (fresh weight). The concentration factor for ¹³⁷Cs in Pteria martensii Dunkar ranged from 4 to 19 in gill tissue. The equilibration time for ¹³⁷Cs in the shell of Portunus dayawanensis was 117 days. For cobalt and zinc in the tissues of Sparus macrocephalus the times were 660 and 473 days respectively. (author)