[M-ZZ47] Marine Manganese Deposits - Genesis, environment, and development -

[MZZ47-P02] Comparative analysis of biodiversity among multiple size classes in seamounts

*Akira Iguchi^1,2, Miyuki Nishijima¹, Eri Ikeuchi^1,2, Taiga Kunishima³, Hiroyuki Yokooka⁴, Hideki Sugishima^5,6, Kazumasa Ikeda⁵, Ryuichi Miwa⁶, Yoshiro Sekido⁷, Nozomu Iwasaki⁸, Masahiro Suzumura⁹, Ayumi Tsukasaki⁹, Yuichiro Tanaka¹, Shogo Kato⁴, Jumpei Minatoya¹⁰, Nobuyuki Okamoto¹⁰, Travis Washburn¹, Atsushi Suzuki^1,2 (1.Geological Survery of Japan, National Institute of Advanced Industrial Science and Technology, 2.Research Laboratory on Environmentally-conscious Developments and Technologies [E-code], AIST, 3.Wakayama Prefectural Museum of Natural History, 4.IDEA Consultants, Inc., 5.Okamoto Glass Co., Ltd., 6.Kaiyo Engineering Co., Ltd., 7.Marine Biological Research Institute of Japan Co., Ltd., 8.Faculty of Geo-Environmental Science, Rissho University, 9.Environmental Management Research Institute, AIST, 10.Japan Oil, Gas and Metals National Corporation)

Keywords:Seamounts, Cobalt-rich ferromanganese crust, Biological communities

In this study, we focused on multiple size classes communities (i.e., microbes, infaunal benthos, and motile megafauna) to clarify differences in biodiversity around a seamount with cobalt-rich crusts off Minami-Torishima Island. The methods used were image analysis obtained using “Edokko Mark I” and genetic analysis using DNA metabarcoding. As a result of the analyses, it was confirmed that the community structure was significantly different between the flat top and the base of the seamounts, and that the degree of difference in community structure between seamounts was also different for each size class. By taking into account the connectivity patterns between seamounts, we hope to elucidate the formation and maintenance mechanisms of seamount communities, and to use this scientific knowledge to contribute to environmental baseline studies and impact assessments for the development of marine mineral resources.