In the North Pacific, it ranges from 20°N to 23°N latitude in the winter, and from 35°N to 50°N latitude in the summer. Approximately 75% of the North Pacific population lives east of the International Date Line, but there is little information regarding the North Pacific distribution. , the U.S. National Marine Fisheries Service estimated that the eastern North Pacific population stood at 374 whales. Two whales tagged in deep waters off California were later recaptured off Washington and British Columbia, revealing a possible link between these areas, but the lack of other tag recovery data makes these two cases inconclusive. Occurrences within the Gulf of California have been fewer. In Sea of Japan and Sea of Okhotsk, whales are not common, although whales were more commonly seen than today in southern part of Sea of Japan from Korean Peninsula to the southern Primorsky Krai in the past, and there had been a sighting in Golden Horn Bay, and whales were much more abundant in the triangle area around Kunashir Island in whaling days, making the area well known as sei – ground, and there had been a sighting of a cow calf pair off the Sea of Japan coast of mid-Honshu during cetacean survey.