|List||World Heritage List|
|Legal Status||Declared property (06/12/1997)|
|Place File No||6/01/101/0007|
|Statement of Significance|
Macquarie Island was
inscribed on the World Heritage List
in 1997 on the basis of its outstanding natural universal values: ·
It provides evidence of the rock types found at great depths in the earth's crust and of plate tectonics and continental drift, the geological processes that have dominated the earth's surface for many millions of years.
It is the only island in the world composed entirely of oceanic crust and rocks from the mantle - deep below the earth's surface.
Macquarie Island probably began as a spreading ridge under the sea with the formation of new oceanic crust somewhere between 11 and 30 million years ago.
At some stage the spreading halted and the crust began to compress, squeezing rocks from deep within the mantle upward like toothpaste from a tube. As the ridge grew it eventually became exposed above the ocean's surface about 600,000 years ago. Thus, rocks normally only occurring deep within the earth's mantle have become exposed on the earth's surface.
Since Macquarie Island emerged, it has mainly been carved by marine processes such as wave action, unlike other subantarctic islands, which have been shaped by glaciers.
The geodiversity of Macquarie Island provides the foundation for the landforms, soils, plants and animals occurring here. It is an island of unique natural diversity, a site of major geoconservation significance and one of the truly remarkable places on earth.
Around the shoreline there is a coastal terrace formed from a wave-cut platform now raised above sea level. Vast waterlogged areas on the coastal platform are heavily vegetated, forming a mire based on deep peat beds and known locally as "featherbed" from the sensation gained when walking over them. Old sea stacks testify to the continual uplifting of the island as they protrude through the peat beds, some of them now being several hundred metres from the existing coastline.
Behind the coastal terrace, steep escarpments rise more than 200 metres to the undulating central plateau which has three peaks over 400 metres, the highest being Mt Hamilton at 433 metres. The plateau scarps are most spectacular at the southern end of the island and along the west coast where the relentless pounding by the Southern Ocean has cut a myriad of rugged bays and coves, fringed with sea stacks and reefs.
The plateau surface is dotted with innumerable lakes, tarns and pools, mainly of structural origin. Fluctuations in sea level and marine erosion have cut away the original escarpments leaving some lakes now perched on the edge of the plateau, while others have been partially or totally drained. The continual westerly winds, which increase in force as they rise over the barrier of the island, and changes in the topography on the plateau, result in dramatic changes in the vegetation cover.
Among the most aesthetically appealing sights of the island are the vast congregations of wildlife, particularly penguins, on suitable parts of the coastal terrace, especially during breeding seasons. The breeding population of royal penguins on Macquarie Island is estimated at over 850,000 pairs - one of the greatest concentrations of sea birds in the world.
Four species of albatross nest on steep and rugged cliffs, both on the main island and on nearby Bishop and Clerk Islands. These are majestic birds, easily viewed when nesting.
Elephant seals also form impressive colonies during the breeding season on suitable beaches. These animals can grow to over 4.5 metres in length and to a weight of 3.5 tonnes. Conflicts between the larger bulls are among the more memorable sights that may be witnessed on the island.
The terrestrial area of Macquarie Island is a State Reserve with protection extending to low water mark. The marine values are protected by the Macquarie Island Marine Park declared by the Commonwealth on 28 October 1999. The primary purpose of the marine park is to protect the conservation values of the region from human disturbance. The marine park contains the world's largest marine highly protected zone, covering more than 16 million hectares.
There are no permanent human inhabitants on Macquarie Island although the Australian Antarctic Division station is occupied year round. The only access to the island is by sea and there are no harbours or landing facilities. Ship-traffic in the area is minimal and mainly consists of resupply vessels for the station.
The reserve, an island
34km long and up to 5km wide, is the exposed crest of the Macquarie Ridge
Complex. This is a component of the oceanic crust, formed in deep water at a
spreading ridge and raised to its present position as the Indian-Australian
tectonic plate interacts with the Pacific plate (Christodoulu et al.
1984). It is perhaps the best preserved section on the globe of oceanic crust
formed in deep water and now exposed above sea level. Volcanic rocks, mainly pillow
lavas with varying proportions of rare massive lava flows, basaltic dykes and
various sediments comprise about 80% of the island (Griffin, 1982; Varne and
Rubenach, 1972). A study of coccoliths in the nanno/foram ooze, characteristic
of ocean floor deposition at depths of between 2,000m and 4,000m (Varne et
al., 1969), indicates that the crust was formed during the early or middle
Miocene (Quilty et al., 1973). The northern part of the island mainly
comprises intrusive rocks apparently derived from deeper crustal levels than
the southern section (Griffin and Varne, 1980; Varne and Rubenach, 1973).
Dolerite dyke swarms are extensive in the northern region and also around
Lusitania Bay and Sandell Bay in the south. Besides the dyke swarms, the
northern section is composed mainly of serpentinised peridotite and gabbro
masses, although there are small areas of extrusive volcanic rocks. |
The main landscape feature is a central rolling plateau 250m-300m above sea level, bounded on all sides by steep cliffs, from the foot of which extends a coastal platform up to 800m wide. Glacial drift up to 20m thick covers much of the plateau and there are several lakes with a combined area of more than 200ha. Numerous smaller lakes, tarns and pools are found both on the plateau and on the raised beach terraces. Soils are gravelly loams and peat. The coastline is generally rocky with a number of offshore islands and stacks (DPWH, 1991).
Meteorological observations have been carried out at the ANARE (Australian National Antarctic Research Expedition) station on the Isthmus during 1911-1913, 1913-1915 and from 1948 to the present.
The island has a cold temperate oceanic climate. Mean seasonal temperature, measured at sea-level, varies from 6.6?C in summer to 3.3?C in winter. Mean annual precipitation is 901mm, falling over an average of 308 days per annum. Some 70% of winds are westerly, cloud cover averages seven-eighths in all months, and mean daily sunshine ranges from 0.6 hours in June to 3.5 hours in February (DPWH, 1991).
The vascular flora comprises at least 46 species, in addition to 80 moss species and at least 50 hepatic species. Lichens number some 141 species, and there are at least 90 diatoms and 20 other species of freshwater algae. The number of marine algae known around the reserve is over 100 (Lowry et al., 1978; Ricker, 1981, 1987), Antarctic kelp Durvillaea antarctica being dominant (DPWH, 1991). Over 135 mushrooms, 60 cup fungi, 22 slime moulds and 1 false slime mould were recently identified (Commonwealth of Australia, 1996).
Since their introduction to the island, rabbits have modified vegetation alliances in most areas. The rabbit control programme, which commenced in 1978, has led to rapid changes in the growth and to a lesser extent the distribution of many vascular species in the reserve (Copson, 1984).
Four main vegetation formations are recognised: tall tussock grassland, short tussock grassland, mire and feldmark (Selkirk et al., 1990). Tall tussock grassland provides the tallest vegetation cover on the island, there being no trees or tall shrubs. It is dominated by Poa foliosa, either in pure stands or allied with P. cookii and/or Stilbocarpa polaris. Herbfield and short grassland cover areas of the raised beach terraces and the plateau. They also occur on extensive areas of coastal slopes which may previously have been covered by tall tussock grassland associations. Mire occurs on areas of the raised beach terraces, valley bottoms and some poorly drained areas on the plateau and rush Juncus scheuchzerioides is dominant in many areas. Feldmark is the most widespread formation, covering approximately half of the island and occupying the most wind-exposed areas of the plateau region and mountain tops. The cushion-forming Azorella macquariensis is the dominant vascular species in the more sheltered parts of the feldmark.
The indigenous fur seal, species unknown, was virtually exterminated within ten years of the island being discovered (Cumpston, 1968). The remaining indigenous mammals are all marine, comprising whales and seals, and include Southern right whale Balaena glacialis, rare sightings of sperm whale Physeter macrocephalus, orca Orcinus orca, the most common whale observed at Macquarie Island, and long fin pilot whale Globicephala melaena, the only other whale to be seen in any numbers around Macquarie Island. The only other positive whale records are southern bottlenose whale Hyperoodon planifrons and Cuviers beaked whale Ziphius cavirostris.
Southern elephant seal Mirounga leonina numbered 110,000 during the mid-1950s (Carrick and Ingham, 1962). New Zealand fur seal Arctocephalus forsteri, sub-Antarctic fur seal A. tropicalis and Antarctic fur seal A. gazella are found. Hookers sea lion Phocarctos hookeri and leopard seal Hydrurga leptonyx visit each winter and spring. Weddell seal Leptonychotes weddelli and crabeater seal Lobodon carcinophagus are very rare vagrants from the south.
Four species of introduced mammal still survive. In 1978 the over wintering population of European rabbit Oryctolagus cuniculus was estimated at 150,000 (Copson et al., 1981), but in December 1978 control measures were begun using myxomatosis, with an initial overall reduction of more than 50% and in some areas a reduction of over 90% (Brothers et al., 1982). In 1993 the rabbit population was estimated at less than 10,000 (Parks and Wildlife Service of Tasmania, 1994). Feral cat Felis catus numbers 170-250; their disastrous effects on some of the smaller indigenous birds have been well documented by Jones (1977) and Brothers (1985). House mouse Mus musculus and ship rat Rattus rattus both became established on the island in the last century (Cumpston, 1968).
Seventy-two species of birds have been recorded at Macquarie Island, comprising two endemic sub-species which became extinct in the 19th century (banded rail Rallus phillippensis macquariensis and red-fronted parakeet Cyanoramphus novaezelandiae erythrolis), 25 breeding species, four probably breeding, 38 non-breeding species and three species of domestic poultry which are no longer on the island). The breeding bird fauna includes four penguin species, four albatrosses, fourteen petrels, two ducks, two passerine, one species each of rail, skua, gull, tern, and an endemic sub-species of king cormorant Phalacrocorax albiventer purpurascens, estimated at 660 pairs (Brothers, 1985).
Penguins are the most numerous birds breeding on the island at the present day. King penguin Aptenodytes patagonicus has recovered dramatically from the slaughter of the last century and the population, estimated at 400,000 in 1989, is still expanding (Rounsevell and Copson, 1982; Scott, 1994); gentoo penguin Pygoscelis papua papua population in the area is about 5,000 breeding pairs (Robertson, 1986; Rounsevell and Brothers, 1984); royal penguin Eudyptes schelegli is endemic to the MacQuarie Island (Woelher. 1984), with a breeding population of 850,000 in 57 colonies (Copson and Rounsevell, 1987); and rockhopper penguin E. chrysocome breed in medium to large colonies with a total population of 500,000 breeding pairs (Rounsevell and Brothers, 1984).
Wandering albatross Diomedea exulans, black-browed albatross D. melanophrys and grey-headed albatross D. chrysostoma occur in lower numbers than the 1,500-2,000 pairs of light-mantled sooty albatross Phoebetria palpebrata (Copson, 1988; Kerry and Colback, 1972; Tomkins, 1985). No native passerine have been recorded, but redpoll Acanthis flammea and common starling Sturnus vulgaris are both widespread and common. Weka Gallirallus australis scotti were introduced from New Zealand in the mid 1800s as a source of food for the sealers (Cumpston, 1968). They probably contributed significantly to the extinction of the endemic sub-species of land rails and parakeets (Taylor, 1979).
The number of fish recorded around the island is 12 benthic and 21 pelagic species (Williams, 1988). Some 27 species of marine mollusc (64%) are endemic (Dell, 1964).
It has been estimated that the MacQuarie Island fauna has probably less than 300 species of terrestrial invertebrates. Approximately 10 percent are endemic with a few others doubtfully so (Greenslade, 1990).
An annotated checklist of mammals, birds and fish is given in DPWH (1991), and of mammals and birds is given in Commonwealth of Australia (1996).
discovered the island in 1810 and inhabited it periodically throughout the 19th
century, exterminating the fur seals and greatly reducing the elephant seal
population. In 1870, gangs came to exploit the king and royal penguins
populations also for oil, eliminating the former. The original elephant seal
population of about 93,000 to 110,000 animals was reduced by 70 percent as a
result of these operations. The visitors also brought exotic mammals and caused
the extermination of two endemic subspecies of land birds.|
|Condition and Integrity Not Available|
About 600 000ha,
located in the Southern Ocean, about half way between New Zealand and the
Antarctic continent, approximately 1,500km south-south-east of Tasmania.
Comprises all those areas of Crown land being the islands known as Macquarie
Island, Bishop and Clerk Islets, 37km to the south, Judge and Clerk Islets,
11km to the north, and including all offshore islands, rocks and reefs
extending in each case to the low water mark. Also included are surrounding
territorial waters to a distance of 12 nautical miles. |
of Parks, Wildlife and Heritage (1991) Macquarie Island Nature Reserve
Management Plan 1991 The Department: Hobart 57pp|
Banks, M.R. and Smith, S.J. (eds.) (1987) Proceedings of the Symposium on Macquarie Island. May 1987. in Pap. Proc. Roy. Soc. Tas., 122 (1)
Clark, M.R. and Dingwall, P.R. (1985) Conservation of islands in the Southern Ocean: a review of the protected areas of Insulantarctica. IUCN. Gland
Report Produced Fri Apr 18 02:38:34 2014