Metabarcoding data in the Ulleung Basin, East Sea of Korea

The East Sea, a semi-enclosed marginal sea in the northwestern Pacific Ocean, is bordered by Korea, Japan, and Russia. It consists of three major basins deeper than 2,000 meters of water depths, the Japan, Yamato, and Ulleung Basins. The Ulleung Basin, located in the southwestern part of the East Sea near the Korean Peninsula, is particularly influenced by upwelling and eddies that enhance biological and geochemical processes, resulting in high biological productivity compared to the Yamato and Japan Basin. These processes are closely linked to the surface sediments of Ulleung Basin, enriched with organic carbon and manganese oxides. Under the suboxic conditions, this sediment composition facilitates carbon oxidation pathways and nutrient cycling through microbial processes, further enhancing the geochemical dynamics in the Ulleung Basin.Additionally, multi-channel seismic data exhibited abundant acoustic chimneys in this basin, which can serve as the gas migration pathways from deep sediment to potentially feed massive gas hydrate accumulations near the seafloor. These unique sedimentary and geophysical features provided ideal conditions for methane hydrate formation and stability in this basin. As a result, the Ulleung Basin serves as a natural laboratory for studying the complex interplay of biological and geological processes in methane-rich marine sediments. Using metabarcoding, this study investigates microbial communities in hydrate-bearing sediments from gas chimney structures in the Ulleung Basin, East Sea of Korea.