[A-OS13] Marine ecosystems and biogeochemical cycles: theory, observation and modeling

[AOS13-P11] Geographic characteristics of fish community structures around Japan revealed by eDNA survey

*Yuan LIN^1,2, Zeshu Zeshu¹, Sk Istiaque AHMED^1,2, Xueding WANG^1,2, Tomihiko HIGUCHI¹, Itsuka YABE¹, Sachihiko ITO¹, Eisuke TSUTSUMI³, Hiroaki SAITO¹, Kosei KOMATSU¹, Atsushi TSUDA¹, Yusuke KAWAGUCHI¹, Eitarou OKA¹, Kyoko OKINO¹, Hajime OBATA¹, Yuki MINEGISHI¹, Hideki FUKUDA¹, Marty Kwok-Shing WONG¹, Jun INOUE¹, Susumu HYODO¹, Shin-Ichi ITO¹ (1.Atmosphere and Ocean Research Institute, The University of Tokyo, 2.Graduate School of Agricultural and Life Sciences, The University of Tokyo, Japan, 3.Faculty of Fisheries, Kagoshima University, Japan)

Keywords:Geographic characteristics, fish community structures, environmental DNA

The Northwest Pacific is one of the regions where possess the richest fishing resources and highest diversity in the world. Especially, around Japan, the complex water mass structures with the western boundary currents, the warm Kuroshio and cold Oyashio, provide abundant living conditions for the biodiversity and fishery resources of the region. However, in recent years, due to overfishing, environmental pollution, and global climate change, the biodiversity and fishery resources have faced continuous challenges that represent the Anthropocene. Therefore, it is an urgent task to understand the large-scale distribution characteristics of fish communities around Japan responding to ocean environments to establish effective fisheries managements and conservation strategies of biodiversity in the Anthropocene.
Environmental DNA (eDNA) technology, which is a non-invasive method, can quickly and efficiently monitor and evaluate aquatic communities only by sampling the environmental waters. We collected water samples from various ocean areas around Japan, covering a variety of ecological zones from coastal regions to open ocean environments. The water samples were collected from 7 different depths (0-200 m) at 187 stations extending from coastal to open ocean during 15 cruises. A total of 1101 samples were analyzed using eDNA metabarcoding, and a total of 1387 species sets were detected. By a non-hierarchical clustering method, all samples are divided into three main groups, which are basically divided by the current structures: the Kuroshio region, Oyashio region and the Tsushima Warm Current region (Sea of Japan side). The Kuroshio and Oyashio regions were divided by the latitudinal position. The species richness was lower in the Tsushima Warm Current region than the other regions, but some part of the Oyashio region also showed lower species richness. The results demonstrate the strong connection between the biodiversity and the current systems surrounding Japan.