Special features of Great Australian Bight Marine Park

The continental shelf in the Bight is very wide, in some places extending well over 200 Nautical Miles. It has the longest ice-free east-west extent of coastline in the Southern Hemisphere and is adjacent to the only circumpolar ocean in the world. The waters are treacherous and the region experiences some of the world's highest and most persistent waves.

A southern right whale and calf.

The Great Australian Bight region is an area of great conservation significance. It provides important calving habitat for the endangered southern right whale and colonies of Australia's only endemic pinniped, the Australian sea lion (Neophoca cinerea), are found there. It supports some of the highest levels of marine diversity found anywhere in Australia, particularly among red algae (sea weed), ascidians (sea squirts), bryozoans, molluscs (shellfish) and echinoderms (sea urchins and sea stars). Many of these species are found nowhere else in the world.

The abundant wildlife in this region exists due to the unique environmental conditions arising from its location in a transitional zone between the warm tropical waters from Western Australia carried to the Great Australian Bight via the Leeuwin current, and the cold waters from other areas around South Australia. The seasonal influence of the Leeuwin current and the localised periodic cold, nutrient-rich up-wellings in the eastern part of the region provide ideal conditions in which biodiversity can prosper.

There are no major land-based watercourses that flow into the Bight. The arid climate of the Nullabor and the flat terrain of the coastline has meant that very little land-based sediment has been washed into the wide continental shelf. This lack of fluvial or land-based deposits has been a major factor in preserving a comprehensive record of global climate and oceanographic changes in the sediments along the southern temperate Australian coastline.

The marine park is in relatively pristine condition due to the low levels of human utilisation, which arises from its isolation and difficult coastal access. Such sites can provide important reference areas for scientific studies and long-term environmental monitoring.