*Chizuru Takashima¹, Tomoyo Okumura², Akihiro Kano³, Susumu Kakubuchi¹ (1.Faculty of Education, Saga University, 2.Center for Advanced Marine Core Research, Kochi University, 3.Department of Earth and Planetary Science The University of Tokyo)

*Shota Amekawa¹, Kenji Kashiwagi², Masako Hori³, Tomomi Sone⁴, Hirokazu Kato¹, Tomoyo Okumura⁵, Tsai-Luen Yu⁶, Chuan-Chou Shen^6,7,8, Akihiro Kano¹ (1.Graduate School of Science, The University of Tokyo, 2.Department of Environmental Biology and Chemistry, Faculty of Science, University of Toyama, 3.Division of Natural Sciences, Osaka Kyoiku University, 4.Marine Works Japan LTD., 5.Center for Advanced Marine Core Research, Kochi University, 6.High-precision Mass Spectrometry and Environment Change Laboratory (HISPEC), Department of Geosciences, National Taiwan University, 7.Global Change Research Center, National Taiwan University, 8.Research Center for Future Earth, National Taiwan University)