[M-ZZ46] Marine Manganese Deposits: Origin, Exploration, and Development

[MZZ46-P07] Biodiversity and connectivity of deep-sea amphipods at seamounts with cobalt-rich ferromanganese crusts in the Northwest Pacific

*Akira Iguchi¹, Eri Ikeuchi¹, Hiroyuki Yokooka², Hideki Sugishima², Kazumasa Ikeda³, Ryuichi Miwa⁴, Miyuki Nishijima¹, Nozomu Iwasaki⁵, Yuichiro Tanaka¹, Taiga Kunishima⁶, Shogo Kato⁷, Junpei Minatoya⁷, Yoshiaki Igarashi⁷, Nobuyuki Okamoto⁷, Atsushi Suzuki¹ (1.National Institute of Advanced Industrial Science and Technology, 2.IDEA Consultants, Inc., 3.Okamoto Glass Co., Ltd., 4.Kaiyo Engineering Co., Ltd., 5.Faculty of Geo-Environmental Science, Rissho University, 6.Wakayama Prefectural Museum of Natural History, 7. Japan Oil, Gas and Metals National Corporation)

Keywords:Seamounts, Cobalt-rich ferromanganese crust, Amphipods, DNA barcoding, Connectivity

To compare biodiversity and connectivity between seamounts with cobalt-rich ferromanganese crusts in the Northwest Pacific, we performed molecular ecological analysis targeting deep-sea amphipods, which are well diversified group in deep-sea area. We established baited traps in several sites and succeeded in collecting many amphipods specimens, likely including several species with different life characters. With these amphipod specimens, DNA barcoding and MOTUs community analysis detected different community structures among depths and seamounts. In addition, we also performed population genetic analysis by targeting several putative species and detected connectivity patterns between seamounts. Our molecular ecological approach using deep-sea amphipods around cobalt-rich ferromanganese crusts demonstrates its usefulness for performing environmental baseline studies and impact assessments in consideration of future deep-sea mining projects.