M Muslim Department of Oceanography, Diponegoro University, Semarang, 50275 Indonesia Indonesia
H. Suseno Marine Radioecology Group, Center for Radiation Safety Technology and Metrology - National Nuclear Energy Agency,
Jl. Lebak Bulus Raya No. 49, Kotak Pos 7043 JKSKL Jakarta Selatan 12070 Indonesia. Indonesia
M.J. Pratiwi Department of Oceanography, Diponegoro University, Semarang, 50275 Indonesia Indonesia