The common dolphin (Delphinus delphis) is the second-most bycaught species in Korean waters. To provide key information about their habitat boundaries and hotspots for spatial conservation and management, the spatial use of this species was examined using data obtained from sighting and bycatch surveys of cetaceans in the past 20 years. The 95% minimum convex polygon and 95% density contour of fixed-kernel analysis suggested that the boundary of the home range of common dolphins is limited to the coastal region (Busan–Sokcho) of the East Sea/Sea of Japan. From 50% density contours drawn by kernel density estimation, it was suggested that their hotspots are around the coast of Ulsan–Pohang, Doghae, and Sokcho within the home range. Common dolphins were not observed in the Yellow Sea. Hence, shallow waters in the geographic area of the coastal region of the Yellow Sea are likely not a suitable habitat for common dolphins in this region.

The common dolphin is the second most bycaught species in Korean waters. To provide key information about their habitat boundaries and hotspots for spatial conservation and management, the spatial use of this species was examined using data obtained from sighting and bycatch surveys of cetacean during the past 20 years. The 95% minimum convex polygon and 95% density contour of fixed kernel suggested that the boundary of home range of common dolphins is limited to the coastal region (Busan-Sokcho) of the East Sea/Sea of Japan. From 50% density contours dawn by kernel density estimation, it was suggested that their hotspots are around the cost of Ulsan-Pohang, Doghae, and Sokcho within the home range. Common dolphins are not at all distributed in the Yellow Sea. Hence, shallow waters, such as the coastal region of the Yellow Sea, are not suitable habitats for common dolphins.