The western gray whale summers in the OkhotskSea, mainly off the northeastern coast of SakhalinIsland (Russian Federation). There are also occasional sightings off the eastern coast of Kamchatka (Russian Federation) and in other coastal waters of the northern OkhotskSea (Vladimirov 1994, Weller et al. 1999). Its migration routes and wintering grounds are poorly known, the only recent information being from occasional records on both the eastern and western coasts of Japan (Kato et al. 2006) and along the Chinese coast (Zhu and Yue 1998). Until 1966, there was a whaling ground off Ulsan (southeastern KoreaPeninsula), where whales were taken during November to April, with two peaks (in December/January and March/April), suggestive of south- and northbound migrations respectively through the Sea of Japan (Kato and Kasuya 2002). However, no gray whales have been recorded in the Korean whaling grounds since 1968. The great majority of recent Japanese records are on the Pacific side, suggesting that this is now the more important migration route. The few modern records from China are scattered along virtually the entire Chinese coast from the northern Yellow Sea to the HainanStrait in the south (Zhu and Yue 1998). The calving grounds are unknown but may be around HainanIsland, this being the southwestern end of the known range (Brownell and Chun 1977).