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Macquarie Island
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Macquarie Island lies in the southwest corner of the Pacific Ocean, about half-way between Australia and Antarctica. 54°37'53"S, 158°52'15"E. Politically, it has formed part of the Australian state of Tasmania since 1900 and became a Tasmanian State Reserve in 1978. In 1997 it became a world heritage site. It was a part of Esperance Municipality until 1993, when the municipality was merged with other municipalities to Huon Valley. Ecologically, it is part of the Antipodes Subantarctic Islands tundra ecoregion.
The Australian Antarctic Division (AAD) maintains a permanent base, the Macquarie Island Station, on the island.
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Encyclopedia
Macquarie Island lies in the southwest corner of the Pacific Ocean, about half-way between Australia and Antarctica. 54°37'53"S, 158°52'15"E. Politically, it has formed part of the Australian state of Tasmania since 1900 and became a Tasmanian State Reserve in 1978. In 1997 it became a world heritage site. It was a part of Esperance Municipality until 1993, when the municipality was merged with other municipalities to Huon Valley. Ecologically, it is part of the Antipodes Subantarctic Islands tundra ecoregion.
The Australian Antarctic Division (AAD) maintains a permanent base, the Macquarie Island Station, on the island. The base's residents, the island's only inhabitants, range in numbers from 20 to 40 people throughout the year.
History
The Australian/Briton Frederick Hasselborough discovered the island accidentally in July 1810 when looking for new sealing grounds. He claimed Macquarie Island for Britain and annexed it to the colony of New South Wales in 1810. The island took its name after Colonel Lachlan Macquarie, Governor of New South Wales from 1810 to 1821. Fabian Gottlieb von Bellingshausen, who explored the area for Alexander I of Russia, produced the first map of Macquarie Island. Bellingshausen landed on the island on November 28, 1820, defined its geographical position and traded his rum and food for Macquarie Island's fauna with the sealers.
In 1890 New South Wales transferred the island to Tasmania, which leased it to Joseph Hatch (1837 - 1928) between 1902 and 1920 for his oil industry based on harvesting penguins.
Between 1911 and 1914, the island became a base for the Australasian Antarctic Expedition under Sir Douglas Mawson. George Ainsworth operated a meteorological station between 1911 and 1913, followed by Harold Power (1913 until 1914) and by Arthur Tulloch from 1914 until its shutdown in 1915. In 1933 the authorities declared the island a wildlife sanctuary and eventually transferred it to the Commonwealth of Australia under the administration of the Australian Antarctic Territory on December 26, 1947. The Australian National Antarctic Research Expeditions (ANARE) established its expedition headquarters on May 25, 1948 on Macquarie Island.
On December 23, 2004 an earthquake measuring 8.1 on the Richter magnitude scale (one of the largest earthquakes ever recorded) rocked the island, but caused little damage.
On April 12, 2008, a 7.1 earthquake on the Macquarie Fault occurred near Macquarie Island.
Geography
The island has an approximate length of 34 km and a width of 5 km, with an area of 128 km². Near Macquarie Island are two minor groups of islets, Judge and Clerk Islets, , 14 km to the north, and 0.2 km² in area, and Bishop and Clerk Islets, , 34 km to the south, and 0.6 km² in area.
The island is in two main pieces of plateau of around 150-200m elevation to north and south, joined by a narrower and lower isthmus. The high points include Mt Elder on the north-east coastal ridge at 385m, and Mt Hamilton and Mt Fletcher in the south at 410m.
Bishop and Clerk Islets mark the southernmost point of Australia (including islands).
Macquarie Island lies atop a geographic feature named for the island, the Macquarie Ridge. This seafloor ridge is aligned along the eastern margin of the tectonic plate boundary between the Indo-Australian Plate and the Pacific Plate.
In the 19th Century Emerald Island was supposed to exist south of Macquarie Island.
Fauna and flora
Fauna found on the island include: Subantarctic Fur Seals, Antarctic Fur Seals, New Zealand Fur Seals and Southern Elephant Seals - over 80,000 individuals of this species. Royal Penguins and Macquarie Shags are endemic breeders, while King Penguins, Southern Rockhopper Penguins and Gentoo penguins also breed here in large numbers.
Ecological balance
The ecology of the island was affected soon after the beginning of European visits to the island in 1810. The island's fur seals, elephant seals and penguins were killed for fur and blubber. Rats and mice that inadvertently introduced from the ships prospered due to lack of predators. Cats were subsequently introduced deliberately to keep the rodents from eating human food stores. In about 1870, rabbits were left on the island by sealers to breed for food. By the 1970s, the then 130,000 rabbits were causing tremendous damage to vegetation.
The feral cats introduced to the island have had a devastating effect on the native seabird population, with an estimated 60,000 seabird deaths per year. From 1985, efforts were undertaken to remove the cats. In June 2000, the last of the nearly 2500 cats were culled in an effort to save the seabirds. Although seabird numbers began to rise initially, the removal of the cats allowed a rapid growth in the number of rats and rabbits which together are causing widespread environmental damage.
The rabbits rapidly multiplied before numbers were reduced to about 10,000 in the early 1980s when myxomatosis was introduced. Rabbit numbers have grown again to around 100,000 on the island. The rodents feed on young chicks while rabbits nibbling on the grass layer has led to soil erosion and cliff collapses, destroying seabird nests. Large portions of the Macquarie Island bluffs are eroding as a result. In September 2006 a large landslip at Lusitania Bay, on the eastern side of the island, partially destroyed an important penguin breeding colony. Tasmania Parks and Wildlife Service attributed the landslip to a combination of heavy spring rains and severe erosion caused by rabbits.
Research by Australian Antarctic Division scientists, published in the 13 January 2009 edition of the British Ecological Society's Journal of Applied Ecology, showed that the success of the feral cat eradication program has allowed the rabbit population to increase, damaging the Macquarie Island ecosystem by altering significant areas of island vegetation.
On 4 June 2007 a media release by the Australian Federal Minister for the Environment and Water Resources, Malcolm Turnbull, announced that the Australian and Tasmanian Governments had reached an agreement to jointly fund the eradication of rodent pests, including rabbits, to protect Macquarie Island's World Heritage values. The plan, estimated to cost $24 million Australian dollars, will involve mass baiting the island similar to an eradication program on New Zealand's Campbell Island and is expected to take up to seven years.
Gallery
Image:MacquarieIsland7.JPG|A Macquarie Island beach
Image:MacquarieIsland4.JPG|Macquarie Island flora
Image:MacquarieIsland5.JPG|Macquarie Island flora just inland from the beach
Image:Royal penguins arguing.jpg|Royal Penguins are arguing
Image:Elephant seals play fight.jpg|Play fight, elephant seals
Image:Macquarie Island geology.png|Simplified geological map
See also
External links
- (Australian Antarctic Division)
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