 Populations are denser close to continental shelves and canyons. Sperm whales are usually found in deep, off-shore waters, but may be seen closer to shore, in areas where the continental shelf is small and drops quickly to depths of 310 to 920 metres (1,020 to 3,020 ft). Coastal areas with significant sperm whale populations include the Azores and Dominica. In Asian waters, whales are also observed regularly in coastal waters in places such as Commander and Kuril Islands, Shiretoko Peninsula, off Kinkasan, vicinity to Tokyo Bay and Boso Peninsula to Izu and Izu Islands, Volcano Islands, Yakushima and Tokara Islands to Ryukyu Islands, Taiwan, Northern Mariana Islands, and so forth. Historical catch records suggest there could have been smaller aggression grounds in the Sea of Japan as well.
