Coasts and Oceans Theme Report
Australia State of the Environment Report 2001 (Theme Report)
Australian State of the Environment Committee, Authors
Published by CSIRO on behalf of the Department of the Environment and Heritage, 2001
ISBN 0 643 06751 5
Habitats and species (continued)
Habitats of Australia's external territories
Australia's seven external territories comprise tropical and temperate islands and a large segment of Antarctica, and include the 200 nm Exclusive Economic Zone surrounding each. The location of several of these islands has resulted in substantial areas of the extended continental shelf being included in Australia's marine area (Figure 2).
Heard Island and McDonald Islands are volcanic in origin and are an undisturbed habitat for sub-Antarctic plants and animals. Heard Island (368 km2) is dominated by the 2745-metre active volcano Big Ben, whose last major eruption was in 1992. McDonald Island (1 km2) is the major island in the McDonald Islands group. They might be described as the wildest places on Earth - a smoking volcano under a burden of snow and glacial ice rising above the world's stormiest waters.
All of Australia's uninhabited Island territories are significant breeding sites or migratory staging posts for birds. Ninety-three bird species have been recorded at Ashmore Reef, and 17 breed on the islands. These islands are also important breeding habitat for other species, such as penguins and seals on Heard Island and the McDonald Islands, and turtles and seabirds on and around the tropical islands.
The Antarctic Treaty provides a framework and governing philosophy for the work of nations in the Antarctic, namely the twin ideals of peace and science. Australia was a driving force behind the development and implementation of a Protocol to the Treaty (the Madrid Protocol) in 1998. The Protocol provides the Antarctic with a comprehensive international environmental protection regime.
Antarctic waters have many biological surprises. The biomass of krill rivals that of the human population, while Crabeater Seals may be the most numerous of all the world's larger animals apart from people. At the other size extreme, Antarctic microbes (algae, protozoa and bacteria) can be abundant and diverse in the marine, terrestrial and lake environments. Marine algae in Antarctic waters play a major role in the draw-down of atmospheric carbon dioxide, and some produce chemicals that induce cloud formation that can influence global climate.