Understanding the Spatial and Temporal Distribution and Environmental Characteristics of Polychaete Assemblages in the Coastal Waters of Ulleungdo, East Sea of Korea

Abstract

The coastal area of Ulleungdo in the East Sea has experienced large climate and environmental changes. However, research on marine benthic animals in this area has been very limited. In the present study, we investigated the spatial and temporal distribution of benthic polychaetes to determine their seasonal adaptability to environmental changes in the coastal waters of Ulleungdo in 2019. In total, 116 species (34 families) of polychaetes were identified with an average of 25 species per site. The average density was 772.8 individuals m−2, with the highest density in August and the lowest in February. The dominant species were Pseudobranchiomma zebuensis (15.6%), Scolelepis sp. (8.6%), Haplosyllis spongiphila (7.3%), and Lumbrineris nipponica (6.3%). The main factors affecting polychaete community structure were water depth and sediment type (gravel, sand, silt, clay). Based on cluster analysis, the polychaetes tended to group mainly in winter and summer with P. zebuensis and Syllis sp. contributing to the grouping. The dominant species was the suspension feeder, which correlated highly with habitat sediment type and was substantially consistent with the coast of Dokdo. Some species overlapped in the East Sea coast, but the number and diversity of species were higher in Ulleungdo. Our study results confirm the ecological characteristics of benthic polychaetes of Ulleungdo and provide information for future monitoring of the environmental and biological changes in the East Sea.

Prey Selectivity in Juvenile Red King Crabs from the Coastal Barents Sea

“…In contrast to Kola Bay, other studies have shown the highest contributions to the total benthic biomass for echinoderms (mainly sea urchins) and bivalves or barnacles [21,66,69]. The observed differences in the structure of benthic communities along a gradient of environmental factors in Kola Bay (Table 2, Figure 2) agree with those found in several estuarine systems with expressed salinity gradients [70][71][72][73].…”

Establishing a Marine Protected Area in the Waters Surrounding Dokdo: Necessity and Legality

“…The South Korean government had long discussed the necessity of such an establishment. The surrounding waters include various invertebrates [20,21]. Figure 2 shows the waters surrounding the northern and western parts of Ulleungdo as a marine protected area.…”

Trophic structure of fish assemblages in two offshore islands (Ulleungdo and Dokdo) of Korea revealed using stable isotope analysis

“…In addition, these islands are known to have unique environmental and biological characteristics that are considerably different from those of mainland coastal regions at the same latitude (Kang et al, 2013;Kang et al, 2019;Chung et al, 2020;Kim et al, 2020). In particular, the coastal ecosystems of Ulleungdo and Dokdo are characterized by high biodiversity and are home to several endangered and endemic species (usually, marine invertebrates and plants) (Song et al, 2017;Kim and Yu, 2021;Kim et al, 2023). Thus, to understand the ecological features of these islands as biological hotspots, it is necessary to characterize the structure and function of marine ecosystems.…”