A long-term ecological monitoring of subtidal macrozoobenthos around Dokdo waters, East Sea, Korea

Dokdo's high marine biodiversity has received worldwide attention recently. A total of 578 macrozoobenthos are recorded since the 1960s, but ecology of Dokdo's fauna is unknown. We monitored Dokdo's subtidal macrozoobenthos for 5 years in 2013–17, in the present study. Five stations representing three subtidal habitats were monitored; 1) oceanic plateau, 2) coastal terrace, and 3) island wharf. In total, 13,664 individuals belonging to 141 taxa were recorded during the survey. The number of species and density varied greatly among stations without distinct year-round variation. Faunal compositions significantly differed in time and space, reflecting varied faunal adaptations in a harsh environment. Whilst, temporal stability in faunal assemblages was evidenced for some dominant or cosmopolitan taxa. High spatial heterogeneity reflects site-specific oceanographic conditions. Meantime, sea-surface temperature and wave action were associated with year-round faunal compositions. Overall, the Dokdo's macrozoobenthos significantly contribute to marine biodiversity of the East Sea. [Display omitted] •Dokdo's subtidal faunal distributions showed high spatial but lesser temporal variations.•High spatial heterogeneity reflected multiple interactions between abiotic and biotic components.•Temporal stability in diversity and abundance of some dominant species was evidenced.•Dokdo's macrozoobenthos significantly contributed to marine biodiversity of the East Sea.•Site-specific conservation strategy would be necessary to protect Dokdo's future ecosystem.