Macquarie Island lies in the southwest Pacific Ocean, about half-way between New Zealand and Antarctica, at 54° 30' S, 158° 57' E. Politically, it is part of Tasmania, Australia since 1900 and became a Tasmanian State Reserve in 1978, and a World Heritage Site in 1997. It was a part of Esperance Municipality until 1993, when the municipality was merged with other municipalities to Huon Valley. The island is home to the entire royal penguin population on earth during their annual nesting season. Ecologically, it is part of the Antipodes Subantarctic Islands tundra ecoregion.
Since 1948 the Australian Antarctic Division (AAD) has maintained a permanent base, the Macquarie Island Station, on the isthmus at the northern end of the island at the foot of Wireless Hill. The population of the base, the island's only human inhabitants, usually varies from 20 to 40 people over the year.
History
The Australian/Briton Frederick Hasselborough discovered the uninhabited island accidentally on 11 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. Hasselborough reported a wreck "of ancient design", which has given rise to speculation that the island may have been visited before by Polynesians or others.
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 28 November 1820, defined its geographical position and traded his rum and food for Macquarie Island's fauna with the sealers. Between 1810 to 1919, seals and then penguins were hunted almost to the point of extinction. The conditions on the island and the surrounding seas were considered so harsh that the idea to use it as a penal settlement was rejected.
In 1877, the crew of the schooner Bencleugh was shipwrecked on the islands for four months. The ship's owner, John Sen Inches Thomson, wrote a book on his sea travels, including his time on the island. The book, written in 1912, was entitled "Voyages and Wanderings In Far-off Seas and Lands".
In 1890, New South Wales transferred the island to Tasmania, which leased it to Joseph Hatch (1837â€"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 to 1914) and by Arthur Tulloch from 1914 until it was shut down in 1915.
In 1933, the authorities declared the island a wildlife sanctuary under the Tasmanian Animals and Birds Protection Act 1928 and in 1972 it was made a State Reserve under the Tasmanian National Parks and Wildlife Act 1970.
The Australian National Antarctic Research Expeditions (ANARE) established its expedition headquarters on 25 May 1948 on Macquarie Island.
On 5 December 1997, Macquarie Island was listed as a World Heritage Site mainly because of its unique geological features.
On 23 December 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 12 April 2008, a 7.1 earthquake on the Macquarie Fault occurred near Macquarie Island.
Geography
Macquarie Island is an exposed portion of the Macquarie Ridge, and is located where the Australian plate meets the Pacific plate. It is the only place in the Pacific Ocean where rocks from the mantle are actively exposed at sea level. Due to this it was made a UNESCO world heritage site in 1997.
The island is about 34 km (21 mi) long and 5 km (3 mi) wide, with an area of 128 km2 (49 sq mi). Near Macquarie Island are two small groups of minor islands, the Judge and Clerk Islets, 54°21′S 159°01′E, 14 km (9 mi) to the north, and 0.2 km2 (49 acres) in area, and the Bishop and Clerk Islets, 55°03′S 158°46′E, 34 km (21 mi) to the south, and 0.6 km2 (150 acres) in area.
The island is in two main pieces of plateau of around 150â€"200 m (490â€"660 ft) elevation to the north and south, joined by a narrow isthmus close to sea level. The high points include Mount Elder on the north-east coastal ridge at 385 m (1,263 ft), and Mounts Hamilton and Fletcher in the south at 410 m (1,345 ft).
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. The Bishop and Clerk Islets mark the southernmost point of Australia (including islands). In the 19th century the phantom Emerald Island supposedly lay to the south of Macquarie Island.
Climate
Macquarie Island's climate is moderated by the sea, and all months have an average temperature above freezing, although snow is common between June and October and may even occur in Macquarie Island's "summer".
Average daily maximum temperatures range from 4.9 °C (40.8 °F) in July to 8.8 °C (47.8 °F) in January. Precipitation occurs fairly evenly throughout the year and averages 967.9 mm (38.11 in) annually. Macquarie Island is one of the cloudiest places on Earth with an average of only 856 hours of sunshine per year, similar to that in Tórshavn in the Faroe Islands.
Flora and fauna
The flora has taxonomic affinities with other subantarctic islands, especially those to the south of New Zealand. Plants rarely grow over 1Â m in height, though the tussock-forming grass Poa foliosa can grow up to 2Â m tall in sheltered areas. There are over 45 vascular plant species and more than 90 moss species, as well as many liverworts and lichens. Woody plants are absent. The island has five principal vegetation formations: grassland, herbfield, fen, bog and feldmark. Bog communities include 'featherbed', a deep and spongy peat bog vegetated by grasses and low herbs, with patches of free water. Endemic flora include the cushion plant Azorella macquariensis, the grass Puccinellia macquariensis, as well as two orchids - Nematoceras dienemum and Nematoceras sulcatum.
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. The island has been identified by BirdLife International as an Important Bird Area because it supports about 3.5 million breeding seabirds of 13 species.
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 were 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 2,500 cats were culled in an effort to save the seabirds. Seabird populations responded rapidly, but rats and rabbits continued to cause 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 then grew again to over 100,000 by 2006. 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, suggested 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. However, in a comment published in the same journal other scientists argued that a number of factors (primarily a reduction in the use of the Myxoma virus) were almost certainly involved and the absence of cats may have been relatively minor among them. The original authors examined the issue in a later reply and concluded that the effect of the Myxoma virus use was small and reaffirmed their original position.
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, was based on mass baiting the island similar to an eradication program on New Zealand's Campbell Island, to be followed up with dog hunting teams trained by Steve Austin over a period of up to seven years. The baiting was expected to inadvertently affect kelp gulls but higher than expected levels of bird deaths caused a temporary suspension of the program. Other species killed by the baits include giant petrels, black ducks and skuas.
In February 2012, The Australian reported that rabbits, rats and mice had been nearly eradicated from the island.
By April 2012, the hunting teams had located and exterminated 13 rabbits still surviving since the baiting in 2011. The last five rabbits found were in November 2011, including a lactating doe and four kittens. No fresh rabbit signs were found up to July 2013. On 8 April 2014 Macquarie Island was officially declared pest-free after seven years of conservation efforts. This achievement is the largest successful island pest-eradication program ever attempted.
Gallery
Wildlife sounds
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See also
- List of administrative heads of Macquarie Island
- List of islands of Australia
- List of Antarctic and subantarctic islands
- Island restoration
- Lachlan Macquarie
- Campbell Macquarie (shipwreck)
References
- Macquarie Island, an 1882 paper in the Transactions of the Royal Society of New Zealand
- Macquarie Island, an 1894 paper in the Transactions of the Royal Society of New Zealand
External links
- Macquarie Island station (Australian Antarctic Division)
- Macquarie Island station webcam
- World heritage listing for Macquarie Island
- Macquarie Island oceanic crust
- A picture of Macquarie Island (historical heritage - Remnants of seal hunting)