Macquarie Island, one of Australia’s subantarctic islands and a site of outstanding geological significance on a world scale, has recently been added to the World Heritage List for its geological wonder. It is the only island in the world composed entirely of oceanic crust and rocks from the mantle – deep below the earth’s surface. Macquarie Island is recognized for its rich and diverse animal life. Around 3.5 million seabirds arrive on Macquarie Island each year to breed and moult. Most of these are penguins. The Macquarie Island Nature Reserve covers the main island, surrounding islands, and includes all of the ocean surrounding the island out to a distance of 3 nautical miles. Macquarie Island is an UNESCO Biosphere Reserve and is listed on the Register of the National Estate. The Macquarie Island World Heritage Area includes the Island and surrounding waters out to a distance of 12 nautical miles. A scientific station on the Island is operated by the Australian Antarctic Division (AAD) on behalf of the Commonwealth Government.