The Sea of Okhotsk Coast (or Okhotsk Coast) is split into natural major parts according to the delineation of the Sea of Okhotsk: its northwestern part, which is part of the mainland of Eastern Siberia (Russian Far East), the west coast of the Kamchatka Peninsula (Russia), the coasts of the Kuril Islands (Russia; some are disputed by Japan), the northeastern coast of Hokkaido (Japan), the north and east coasts of Sakhalin (Russia),[1][2][3] as well as the coasts of the inner islands.