Great Australian Bight

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Great Australian Bight
Great Australian Bight Marine Park.jpg
Coastline of the Great Australian Bight, showing the marine park
Great Australian Bight is located in Australia
Great Australian Bight
Great Australian Bight
Location in Australia
Great Australian Bight Limits.svg
Limits of the Great Australian Bight (in red as defined by the International Hydrographic Organization, in green by the Australian Hydrographic Service).
Location South Australia, Tasmania, Victoria, Western Australia
Coordinates 33°S 130°E / 33°S 130°E / -33; 130Coordinates: 33°S 130°E / 33°S 130°E / -33; 130[1][2]
Type Oceanic bight
Primary outflows Southern Ocean; South Pacific Ocean
Basin countries Australia

The Great Australian Bight is a large oceanic bight, or open bay, off the central and western portions of the southern coastline of mainland Australia.

Extent[edit]

The Great Australian Bight south of the Nullarbor. Credit Jacques Descloitres, Visible Earth, NASA.

Two definitions of the extent are in use - one used by the International Hydrographic Organization (IHO) and the other used by the Australian Hydrographic Service (AHS).

The IHO defines the Great Australian Bight as having the following limits:[3]

On the North. The south coast of the Australian mainland.

On the South. A line joining West Cape Howe (35°08′S 117°37′E / 35.133°S 117.617°E / -35.133; 117.617) Australia to South West Cape, Tasmania.

On the East. A line from Cape Otway, Victoria to King Island and thence to Cape Grim, the northwest extreme of Tasmania.

The AHS defines the bight with a smaller area, from Cape Pasley, Western Australia, to Cape Carnot, South Australia - a distance of 1,160 kilometres (720 mi).[4][5]

Much of the bight lies due south of the expansive Nullarbor Plain, which straddles South Australia and Western Australia. The Eyre Highway passes close to the cliffs of the bight between the Head of the Bight and Eucla.

The Great Australian Bight is sometimes considered part of the Indian Ocean.[6] The AHS considers it to be part of the Southern Ocean, using the expanded Australian definition used for this ocean.[4] The IHO in its Limits of Oceans and Seas (1953)[3] does not specify an ocean explicitly, but groups the bight with the South Pacific Ocean, Bass Strait and Tasman Sea.

Great Australian Bight Marine Park, 2007

Exploration[edit]

The Great Australian Bight was first encountered by European explorers in 1627, when a Dutch navigator, François Thijssen, sailed along its western margins. The coast was later first accurately charted by the English explorer Matthew Flinders in 1802, during his circumnavigation of the Australian continent. A later land-based survey was accomplished by Edward John Eyre.

Natural history[edit]

The coast line of the Great Australian Bight is characterised by cliff faces (up to 60 m high), surfing beaches and rock platforms, ideal for whale-watching. The waters of the Great Australian Bight, despite being relatively shallow, are not fertile. While most continental shelves are rich in sea life and make popular fishing areas, the barren deserts north of the bight have very little rainfall, and what there is mostly flows inland, to dissipate underground or in salt lakes. In consequence, the Great Australian Bight receives very little of the runoff that fertilises most continental shelves and is essentially a marine desert. It is probably best noted for the large number of sharks that frequent its coastal waters, as well as the increasing numbers of Southern Right Whales that migrate within the region, especially at the Head of Bight.

One location on the bight that is specifically oriented towards the understanding of the natural history on its coastline is the Eyre Bird Observatory.

Current conditions[edit]

Economically, the Bight has been exploited over many years as part of the fishing, whaling and shellfish industries. Bluefin tuna have been a favoured target of fishing in the Bight.

The settlements existing along the coastline of the bight, such as Ceduna and Eucla have facilities to access the bight. Some other locations on the Eyre Highway or located on the Nullarbor do not have facilities or easy access.

See also[edit]

References[edit]

  1. ^ "Great Australian Bight (WA)". Gazetteer of Australia online. Geoscience Australia, Australian Government. 
  2. ^ "Great Australian Bight (SA)". Gazetteer of Australia online. Geoscience Australia, Australian Government. 
  3. ^ a b "Limits of Oceans and Seas, 3rd edition" (PDF). International Hydrographic Organization. 1953. Retrieved 7 February 2010. 
  4. ^ a b "AHS – AA609582" (PDF). The Australian Hydrographic Service. 5 July 2012. Retrieved 30 May 2013. 
  5. ^ "Great Australian Bight". Encyclopaedia Britannica. Retrieved 29 September 2011. 
  6. ^ "Marine Gazetteer Placedetails". VLIZ. Retrieved 30 May 2013. 

Further reading[edit]

  • Edminds, Jack (1976) Panorama of Western Australia : the Great Australian Bight Perth,W.A. Periodicals Division, West Australian Newspapers. ISBN 0-909699-11-9 (ANB/PRECIS SIN 0140147)

External links[edit]