Abundance, seasonal haul-out patterns and conservation of spotted seals Phoca largha along the coast of Bak-ryoung Island, South Korea

Abstract

The spotted seal Phoca largha, which is found in the Okhotsk, Bering, Chukchi, Beaufort and Yellow seas, is Critically Endangered in the Yellow Sea of China and Korea because of habitat destruction and human harassment in the region. Shipboard surveys were conducted in the inshore waters of Bak-ryoung Island off western South Korea from March 2000 to October 2002 to investigate the distribution, abundance and seasonal haul-out patterns of spotted seals and thereby to lay a foundation for developing conservation measures. Seals were seen on every survey during the study period, hauled out on offshore rocks rather than on beaches. The highest concentration of spotted seals occurred on Mul-Beum Rock, probably because of the relatively lower exposure of this site to waves and spray. There was a seasonal pattern in the total number of seals hauled out, with the highest numbers seen from late spring to late summer. Spotted seals arrived as early as 15 March and left the area by late December. We suggest that spotted seals spend the spring, summer and autumn feeding along the coast of Bak-ryoung Island and return to their breeding grounds in Liaodong Bay, China, in October. Because the spotted seal populations of China and South Korea are small and seasonally dispersed, the establishment of an international protected areas network and research cooperation between China and South Korea is urgently required.