“…A large number of investigations on plutonium isotopes in soil, sediments, seawater and coral in the Northern Hemisphere (Wang and Yamada, 2005;Zheng et al, 2012;Zhang et al, 2018;Xu et al, 2018;Wang et al, 2017;Liu et al, 2011Liu et al, , 2020Wu et al, 2014;Dong et al, 2010;Roviello et al, 2020;Guan et al, 2021;Yamada et al, 2021) and Southern Hemisphere (Srncik et al, 2014;Tims et al, 2016) have been J o u r n a l P r e -p r o o f 3 reported. Among of them, the marginal seas of the western Pacific Ocean, e.g.…”