Heard Island and McDonald Islands
Encyclopedia
The Heard Island and McDonald Islands (abbreviated as HIMI) are an Australian external territory
and volcanic group
of barren Antarctic
islands, about two-thirds of the way from Madagascar
to Antarctica. The group's overall size is 372 square kilometres (144 sq mi) in area and it has 101.9 km (63 mi) of coastline. Discovered in the mid-19th century, they have been territories of Australia since 1947 and contain the only two active volcano
es in Australian territory, one of which, Mawson Peak
, is the highest Australian mountain. They lie on the Kerguelen Plateau
in the Indian Ocean
.
The islands are among the most remote places on Earth: They are located approximately 4099 km (2,547 mi) southwest of Perth
, 3845 km (2,389.2 mi) southwest of Cape Leeuwin
, Australia, 4200 km (2,609.8 mi) southeast of South Africa
, 3830 km (2,379.9 mi) southeast of Madagascar
, 1630 km (1,012.8 mi) north of Antarctica, and 450 km (279.6 mi) southeast of Kerguelen. The islands are currently uninhabited.
Heard Island, by far the largest of the group, is a 368 square kilometres (142.1 sq mi) bleak and mountainous island located at 53°06′00"S 73°31′00"E. Its mountains are covered in glaciers (the island is 80% covered with ice) and dominated by Mawson Peak
, a 2745 metres (9,006 ft) high complex volcano
which forms part of the Big Ben
massif
. A July 2000 satellite image from the University of Hawaii
's Institute of Geophysics and Planetology (HIGP) Thermal Alert Team, University of Hawai'i showed an active 2 kilometres (1.2 mi) long (and 50–90 m (164–295.3 ft) wide) lava flow trending south-west from the summit of Big Ben.
Mawson Peak is the highest Australian mountain (higher than Mount Kosciuszko
), and one of only 2 active volcanoes in Australian territory, the other being McDonald Island. A long thin sand and gravel spit
named "Elephant Spit
" extends from the eastern end of the island. There is a small group of islets and rocks about 10 kilometres (6 mi) north of Heard Island, consisting of Shag Islet, Sail Rock, Morgan Island and Black Rock. They total about 1.1 square kilometre (0.424712374451789 sq mi) in area.
The McDonald Islands are located 44 kilometres (27.3 mi) to the west of Heard Island at 53°02′20"S 72°36′04"E. The islands are small and rocky. In 1980 they consisted of McDonald Island (186 metres (610.2 ft) high), Flat Island (55 metres (180.4 ft) high) and Meyer Rock (170 metres (557.7 ft) high). They totalled approximately 2.5 square kilometre (0.965255396481338 sq mi) in area, where McDonald Island was 1.13 square kilometre (0.436295439209565 sq mi) large. Like Heard Island, they were surface exposures of the Kerguelen Plateau
.
The volcano on McDonald Island, after being dormant for 75,000 years, became active in 1992 and has erupted several times since. A satellite image taken in 2004 showed that recent volcanic activity had joined McDonald Island and Flat Island into one island and generally doubled the land size of the resultant island. As a result of volcanic activity between November 2000 and the end of 2001 the area of McDonald Island increased to 2.45 square kilometre (0.945950288551711 sq mi) and the highest summit now was at least 230 metres (754.6 ft) high. However, the volcanic activity destroyed nearly all the vegetation on the island. The most recent eruption is thought to have been on 10 August 2005.
Currently there is on-going regeneration of vegetation.
Heard Island and the McDonald Islands have no ports or harbours; ships must anchor offshore. The coastline is 101.9 kilometres (63.3 mi), and a 12 nmi (22.2 km; 13.8 mi) territorial sea and 200 nmi (370.4 km; 230.2 mi) exclusive fishing zone are claimed.
The antipode
to the central Mawson Peak of Heard Island is located less than 70 kilometres (43.5 mi) West by south of Prince Albert, Saskatchewan
, Canada.
ecoregion
that includes several subantarctic
islands. In this cold climate plant life is mainly limited to grasses, moss
es and lichen
s. Low plant diversity reflects the islands’ isolation, small size, severe climate, the short, cool growing season and, for Heard Island, substantial permanent ice cover. The main environmental determinants of vegetation on subantarctic islands are wind exposure, water availability, parent soil composition, salt spray exposure, nutrient availability, disturbance by trampling (from seabirds and seals) and, possibly, altitude. At Heard Island, exposure to salt spray and the presence of breeding and moulting seabirds and seals are particularly strong influences on vegetation composition and structure in coastal areas.
(a period with a cool and moist climate.) Neither group of plants is present today, although potential Tertiary survivors include the vascular plant Pringlea antiscorbutica and six moss species. Volcanic activity has altered the distribution and abundance of the vegetation. The vascular flora covers a range of environments and, although only six species are currently widespread, glacial retreat and the consequent connection of previously separate ice–free areas is providing opportunities for further distribution of vegetation into adjacent areas.
flowering plants and bryophyte
s are the major vegetation components. The vascular flora comprises the smallest number of species of any major subantarctic island group, reflecting its isolation, small ice–free area and severe climate. Twelve vascular species are known from Heard Island, of which five have also been recorded on McDonald Island. None of the vascular species is endemic, although Pringlea antiscorbutica, Colobanthus kerguelensis
, and Poa kerguelensis
occur only on subantarctic islands in the southern Indian Ocean.
The plants are typically subantarctic, but with a higher abundance of the cushion-forming Azorella selago
than other subantarctic islands. Heard Island is the largest subantarctic island with no confirmed human–introduced plants. Areas available for plant colonisation on Heard Island are generally the result of retreating glaciers or new ice–free land created by lava flows. Today, substantial vegetation covers over 20 km2 of Heard Island, and is best developed on coastal areas at elevations below 250 m.
occur at a number of sites around Heard Island and at least 17 other species of seaweed are known, with more to be added following the identification of recent collections. Low seaweed diversity is due to the island's isolation from other land masses, unsuitable beach habitat, constant abrasion by waves, tides and small stones, and the extension of glaciers into the sea in many areas.
now absent from the Heard Island flora may colonise the island if climate change produces more favourable conditions.
Some plant species are spreading and modifying the structure and composition of communities, some of which are also increasing in distribution. It is likely that further changes will occur, and possibly at an accelerated rate. Changes in population numbers of seal and seabird species are also expected to affect the vegetation by changing nutrient availability and disturbance through trampling.
One plant species on Heard Island, Poa annua
, a cosmopolitan grass native to Europe, was possibly introduced by humans, though is more likely to have arrived naturally, probably by skua
s from the Kerguelen Islands where it is widespread. It was initially recorded in 1987 in two recently deglaciated areas of Heard Island not previously exposed to human visitation, while being absent from known sites of past human habitation. Since 1987 Poa annua populations have increased in density and abundance within the original areas and have expanded beyond them. Expeditioner boot traffic during the Australian Antarctic program expedition in 1987 may be at least partly responsible for the spread, but it is probably mainly due to dispersal by wind and the movement of seabirds and seals around the island.
The potential for introducing additional plant species (including invasive species not previously found on subantarctic islands) by both natural and human–induced means is high. This is due to the combination of low species diversity and climatic amelioration. During the 2003/04 summer a new plant species, Cotula plumosa
, was recorded. Only one small specimen was found growing on a coastal river terrace that had experienced substantial development and expansion of vegetation over the past decade. The species has a circumantarctic distribution and occurs on many subantarctic islands.
s, seals
and penguin
s.
at Heard Island came to an end in the late 19th century, after the seal populations there had either become locally extinct or reduced to levels too low to exploit economically. Since then the populations have generally increased and are protected. Seals breeding on Heard include the Southern Elephant Seal
, the Antarctic Fur Seal
and the Subantarctic Fur Seal
. Leopard Seal
s visit regularly in winter to haul-out
though they do not breed on the islands. Crabeater
, Ross
and Weddell Seal
s are occasional visitors.
Nineteen species of birds have been recorded as breeding on Heard Island and the McDonald Islands, although recent volcanic activity at the McDonald Islands in the last decade is likely to have reduced vegetated and un–vegetated nesting areas.
Penguins are by far the most abundant birds on the islands, with four breeding species present, comprising King
, Gentoo
, Macaroni
and Eastern Rockhopper Penguin
s. The penguins mostly colonise the coastal tussock and grasslands of Heard Island, and have previously been recorded as occupying the flats and gullies on McDonald Island.
Other seabirds recorded as breeding at Heard Island include three species of albatross (Wandering
, Black–browed
and Light-mantled Albatross
es, Southern Giant Petrel
s, Cape Petrel
s, four species of burrowing petrels Antarctic
and Fulmar Prion
s, Common and South Georgian Diving-Petrels), Wilson's Storm-Petrel
s, Kelp Gull
s, Subantarctic Skuas, Antarctic Tern
s and the Heard Shag
. Although not a true seabird, the Heard Island subspecies of the Black-faced Sheathbill
also breeds on the island. Both the shag and the sheathbill are endemic to Heard Island.
A further 28 seabird species are recorded as non–breeding visitors or from at–sea surveys. All recorded breeding species, other than the Heard Island sheathbill, are listed marine species under the Australian Environmental Protection and Biodiversity Act (1999, four are listed as threatened species and five are listed migratory species. Under the EPBC Act a recovery plan has been made for albatrosses and giant petrels, which calls for ongoing population monitoring of the species found at HIMI, and at the time of preparing this Plan a draft recovery plan has also been made for the Heard Island cormorant and Antarctic tern.
The recorded populations of some seabird species found in the Reserve have shown marked change. The King Penguin population is the best studied seabird species on Heard Island and has shown a dramatic increase since first recorded in 1947/48, with the population doubling every five years or so for more than 50 years.
A paper reviewing population data for the Black–browed Albatross between 1947 and 2000/01 suggested that the breeding population had increased to approximately three times that present in the late 1940s, although a Convention for the Conservation of Antarctic Marine Living Resources CCAMLR) Working Group was cautious about the interpretation of the increasing trend given the disparate nature of the data, as discussed in the paper. The discovery of a large, previously unknown, colony of Heard Shags in 2000/01 at Cape Pillar raised the known breeding population from 200 pairs to over 1000 pairs. On the other hand, the breeding population of Southern Giant Petrels decreased by more than 50% between the early 1950s and the late 1980s.
Two species, including the thrip Apterothrips apteris and the mite Tyrophagus putrescentiae are thought to be recent, possibly natural, introductions. An exotic species of earthworm Dendrodrilus rubidus was also collected in 1929 from a dump near Atlas Cove, and has recently been collected from a variety of habitats including wallows, streams and lakes on Heard Island.
The arthropods of Heard Island are comparatively well known with 54 species of mite and tick, one spider and eight springtails recorded. A study over summer at Atlas Cove in 1987/88 showed overall densities of up to 60 000 individual springtails per square metre in soil under stands of Pringlea antiscorbutica. Despite a few recent surveys, the non–arthropod invertebrate fauna of Heard Island remain poorly known.
Beetles and flies dominate Heard Island's known insect fauna, which comprises up to 21 species of ectoparasite (associated with birds and seals) and up to 13 free-living species. Approximately half of the free–living insects are habitat-specific, while the remainder are generalists found in a variety of habitats, being associated with either supralittoral or intertidal zones, Poa cookii and Pringlea antiscorbutica stands, bryophytes, lichen-covered rocks, exposed rock faces or the underside of rocks. There is a pronounced seasonality to the insect fauna, with densities in winter months dropping to a small percentage (between
0.75%) of the summer maximum. Distinct differences in relative abundances of species between habitats has also been shown, including a negative relationship between altitude and body size for Heard Island weevils.
The fauna of the freshwater pools, lakes, streams and mires found in the coastal areas of Heard Island are broadly similar to those on other subantarctic islands of the southern Indian Ocean. Many species reported from Heard Island are found elsewhere. Some sampling of freshwater fauna has been undertaken during recent expeditions and records to date indicate that the freshwater fauna includes a species of Protista, a gastrotrich, two species of tardigrade, at least four species of nematode, 26 species of rotifer, six species of annelid and 14 species of arthropod.
As with the other shore biota, the marine macro-invertebrate fauna of Heard Island is similar in composition and local distribution to other subantarctic islands, although relatively little is known about the Heard Island communities compared with the well-studied fauna of some other islands in the subantarctic region, such as Macquarie
and Kerguelen.
Despite Heard Island's isolation, species richness is considered to be moderate, rather than depauperate, although the number of endemic species reported is low. The large macro-alga Durvillaea antarctica supports a diverse array of invertebrate taxa and may play an important role in transporting some of this fauna to Heard Island.
The rocky shores of Heard Island exhibit a clear demarcation between fauna of the lower kelp holdfast zone and the upper shore zone community, probably due to effects of desiccation, predation and freezing in the higher areas. The limpet Nacella kerguelensis is abundant in the lower part of the shore, being found on rock surfaces and on kelp holdfasts. Other common but less abundant species in this habitat include the chiton Hemiarthrum setulosum and the starfish Anasterias mawsoni. The amphipod Hyale sp. and the isopod Cassidinopsis sp. are closely associated with the kelp. Above the kelp holdfast zone, the littornid Laevilitorina (Corneolitorina) heardensis and the bivalve mollusc Kidderia bicolor are found in well–sheltered situations, and another bivalve Gaimardia trapesina trapesina has been recorded from immediately above the holdfast zone. Oligochaetes are also abundant in areas supporting porous and spongy layers of algal mat.
The HIMI wetland is listed on the Directory of Important Wetlands in Australia and, in a recent analysis of Commonwealth–managed wetlands, was ranked highest for nomination under the Convention on Wetlands of International Importance Especially as Waterfowl Habitat (Ramsar Convention) as an internationally important wetland.
Six wetland types have been identified from HIMI covering approximately 1860 ha: coastal ‘pool complex’ (237 ha); inland ‘pool complex’ (105 ha); vegetated seeps mostly on recent glaciated areas (18 ha); glacial lagoons (1103 ha); non-glacial lagoons (97ha); Elephant Spit (300 ha) plus some coastal areas. On Heard Island, the majority of these types suites are found below 150m asl The wetland vegetation occurs in the ‘wet mixed herbfield’ and ‘coastal biotic vegetation’ communities described above.
The wetlands provide important breeding and feeding habitat for a number of Antarctic and subantarctic wetland animals. These include the southern elephant seal and macaroni, gentoo, king and southern rockhopper penguins, considered to be wetland species under the Ramsar Convention. Non–wetland vegetated parts of the islands also support penguin and other seabird colonies.
Magnet during a voyage from Kerguelen to the Antarctic and was believed to have entered the island on his 1833 chart.
An American sealer, Captain John Heard, on the ship Oriental, sighted the island on 25 November 1853, en route from Boston
to Melbourne. He reported the discovery one month later and had the island named after him. Captain William McDonald aboard the Samarang discovered the nearby McDonald Islands six weeks later, on 4 January 1854.
No landing was made on the islands until March 1855, when sealers from the Corinthian, led by Captain Erasmus Darwin Rogers, went ashore at a place called Oil Barrel Point. In the sealing period from 1855 to 1880, a number of American sealers spent a year or more on the island, living in appalling conditions in dark smelly huts, also at Oil Barrel Point. At its peak the community consisted of 200 people. By 1880, most of the seal population had been wiped out and the sealers left the island. In all, more than 100,000 barrels of elephant seal
oil was produced during this period.
There are a number of wrecks in the vicinity of the islands. There is also a discarded building left from John Heard's sealing station which is situated near Atlas Cove.
The islands have been a territory of Australia since 1947, when they were transferred from the U.K. The archipelago became a World Heritage Site
in 1997.
Island and the McDonald Islands was transferred to the Australian government on 26 December 1947 at the commencement of the first Australian National Antarctic Research Expedition (ANARE) to Heard Island, with a formal declaration that took
place at Atlas Cove. The transfer was confirmed by an exchange of letters between the two governments on 19 December 1950.
The islands are a territory (Territory of Heard Island and McDonald Islands) of Australia administered from Hobart
by the Australian Antarctic Division
of the Australian Department of the Environment and Water Resources. They are populated by large numbers of seal and bird species. The islands are contained within a 65000 square kilometres (25,096.6 sq mi) marine reserve and are primarily visited for research. There is no permanent human habitation.
From 1947 until 1955 there were camps of visiting scientists on Heard Island (at Atlas Cove
in the northwest, which was in 1969 again occupied by American scientists and expanded in 1971 by French scientists) and in 1971 on McDonald Island (at Williams Bay). Later expeditions used a temporary base at Spit Bay
in the northeast, such as in 1988, 1992–93 and 2004–05.
With no population, there is no indigenous economic activity. The islands' only natural resource is fish; the Australian government allows limited fishing in the surrounding waters. Despite the lack of population, the islands have been assigned the country code
HM in ISO 3166-1
(ISO 3166-2:HM
) and therefore the Internet top-level domain
.hm
. The timezone of the islands is UTC+5.
States and territories of Australia
The Commonwealth of Australia is a union of six states and various territories. The Australian mainland is made up of five states and three territories, with the sixth state of Tasmania being made up of islands. In addition there are six island territories, known as external territories, and a...
and volcanic group
Volcanic group
A volcanic group is a collection of related volcanoes or volcanic landforms. Note that the term is also used in a different sense when it denotes a suite of associated rock strata largely of volcanic origin; see group for details.-Notable volcanic groups:-See also:*Complex...
of barren Antarctic
Antarctic
The Antarctic is the region around the Earth's South Pole, opposite the Arctic region around the North Pole. The Antarctic comprises the continent of Antarctica and the ice shelves, waters and island territories in the Southern Ocean situated south of the Antarctic Convergence...
islands, about two-thirds of the way from Madagascar
Madagascar
The Republic of Madagascar is an island country located in the Indian Ocean off the southeastern coast of Africa...
to Antarctica. The group's overall size is 372 square kilometres (144 sq mi) in area and it has 101.9 km (63 mi) of coastline. Discovered in the mid-19th century, they have been territories of Australia since 1947 and contain the only two active volcano
Volcano
2. Bedrock3. Conduit 4. Base5. Sill6. Dike7. Layers of ash emitted by the volcano8. Flank| 9. Layers of lava emitted by the volcano10. Throat11. Parasitic cone12. Lava flow13. Vent14. Crater15...
es in Australian territory, one of which, Mawson Peak
Mawson Peak
Mawson Peak is a mountain on Heard Island, an external Australian territory in the Southern Ocean. With its summit at , it is the second highest peak in any state or territory of Australia, surpassed only by the Mount McClintock in the Britannia Range in Australian Antarctic Territory...
, is the highest Australian mountain. They lie on the Kerguelen Plateau
Kerguelen Plateau
The Kerguelen Plateau is an underwater volcanic large igneous province , also the microcontinent and submerged continent in the southern Indian Ocean. It lies about 3,000 km to the southwest of Australia and is nearly three times the size of Japan...
in the Indian Ocean
Indian Ocean
The Indian Ocean is the third largest of the world's oceanic divisions, covering approximately 20% of the water on the Earth's surface. It is bounded on the north by the Indian Subcontinent and Arabian Peninsula ; on the west by eastern Africa; on the east by Indochina, the Sunda Islands, and...
.
The islands are among the most remote places on Earth: They are located approximately 4099 km (2,547 mi) southwest of Perth
Perth, Western Australia
Perth is the capital and largest city of the Australian state of Western Australia and the fourth most populous city in Australia. The Perth metropolitan area has an estimated population of almost 1,700,000....
, 3845 km (2,389.2 mi) southwest of Cape Leeuwin
Cape Leeuwin
Cape Leeuwin is the most south-westerly mainland point of the Australian Continent, in the state of Western Australia.A few small islands and rocks, the St Alouarn Islands, extend further to the south. The nearest settlement, north of the cape, is Augusta. South-east of Cape Leeuwin, the coast...
, Australia, 4200 km (2,609.8 mi) southeast of South Africa
South Africa
The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...
, 3830 km (2,379.9 mi) southeast of Madagascar
Madagascar
The Republic of Madagascar is an island country located in the Indian Ocean off the southeastern coast of Africa...
, 1630 km (1,012.8 mi) north of Antarctica, and 450 km (279.6 mi) southeast of Kerguelen. The islands are currently uninhabited.
Geography
Mawson Peak
Mawson Peak is a mountain on Heard Island, an external Australian territory in the Southern Ocean. With its summit at , it is the second highest peak in any state or territory of Australia, surpassed only by the Mount McClintock in the Britannia Range in Australian Antarctic Territory...
, a 2745 metres (9,006 ft) high complex volcano
Complex volcano
A complex volcano, also called a compound volcano, is a volcano with more than one feature. They form because changes of their eruptive characteristics or the location of multiple vents in an area...
which forms part of the Big Ben
Big Ben (Heard Island)
Big Ben is a volcanic massif that dominates the geography of Heard Island in the southern Indian Ocean. It is a composite cone with a diameter of approximately 25 kilometres. Its highest peak is Mawson Peak, which is 2,745 m above sea level. Much of it is covered by ice, including 14...
massif
Massif
In geology, a massif is a section of a planet's crust that is demarcated by faults or flexures. In the movement of the crust, a massif tends to retain its internal structure while being displaced as a whole...
. A July 2000 satellite image from the University of Hawaii
University of Hawaii
The University of Hawaii System, formally the University of Hawaii and popularly known as UH, is a public, co-educational college and university system that confers associate, bachelor, master, and doctoral degrees through three university campuses, seven community college campuses, an employment...
's Institute of Geophysics and Planetology (HIGP) Thermal Alert Team, University of Hawai'i showed an active 2 kilometres (1.2 mi) long (and 50–90 m (164–295.3 ft) wide) lava flow trending south-west from the summit of Big Ben.
Mawson Peak is the highest Australian mountain (higher than Mount Kosciuszko
Mount Kosciuszko
Mount Kosciuszko is a mountain located in the Snowy Mountains in Kosciuszko National Park. With a height of 2,228 metres above sea level, it is the highest mountain in Australia...
), and one of only 2 active volcanoes in Australian territory, the other being McDonald Island. A long thin sand and gravel spit
Spit (landform)
A spit or sandspit is a deposition landform found off coasts. At one end, spits connect to land, and extend into the sea. A spit is a type of bar or beach that develops where a re-entrant occurs, such as at cove's headlands, by the process of longshore drift...
named "Elephant Spit
Elephant Spit
Elephant Spit is a 9 km long sand spit at the eastern end of subantarctic Heard Island, in the Australian territory of Heard Island and McDonald Islands, lying in the Southern Ocean on the Kerguelen Plateau about 450 km south-east of the Kerguelen Islands...
" extends from the eastern end of the island. There is a small group of islets and rocks about 10 kilometres (6 mi) north of Heard Island, consisting of Shag Islet, Sail Rock, Morgan Island and Black Rock. They total about 1.1 square kilometre (0.424712374451789 sq mi) in area.
The McDonald Islands are located 44 kilometres (27.3 mi) to the west of Heard Island at 53°02′20"S 72°36′04"E. The islands are small and rocky. In 1980 they consisted of McDonald Island (186 metres (610.2 ft) high), Flat Island (55 metres (180.4 ft) high) and Meyer Rock (170 metres (557.7 ft) high). They totalled approximately 2.5 square kilometre (0.965255396481338 sq mi) in area, where McDonald Island was 1.13 square kilometre (0.436295439209565 sq mi) large. Like Heard Island, they were surface exposures of the Kerguelen Plateau
Kerguelen Plateau
The Kerguelen Plateau is an underwater volcanic large igneous province , also the microcontinent and submerged continent in the southern Indian Ocean. It lies about 3,000 km to the southwest of Australia and is nearly three times the size of Japan...
.
The volcano on McDonald Island, after being dormant for 75,000 years, became active in 1992 and has erupted several times since. A satellite image taken in 2004 showed that recent volcanic activity had joined McDonald Island and Flat Island into one island and generally doubled the land size of the resultant island. As a result of volcanic activity between November 2000 and the end of 2001 the area of McDonald Island increased to 2.45 square kilometre (0.945950288551711 sq mi) and the highest summit now was at least 230 metres (754.6 ft) high. However, the volcanic activity destroyed nearly all the vegetation on the island. The most recent eruption is thought to have been on 10 August 2005.
Currently there is on-going regeneration of vegetation.
Heard Island and the McDonald Islands have no ports or harbours; ships must anchor offshore. The coastline is 101.9 kilometres (63.3 mi), and a 12 nmi (22.2 km; 13.8 mi) territorial sea and 200 nmi (370.4 km; 230.2 mi) exclusive fishing zone are claimed.
The antipode
Antipodes
In geography, the antipodes of any place on Earth is the point on the Earth's surface which is diametrically opposite to it. Two points that are antipodal to one another are connected by a straight line running through the centre of the Earth....
to the central Mawson Peak of Heard Island is located less than 70 kilometres (43.5 mi) West by south of Prince Albert, Saskatchewan
Prince Albert, Saskatchewan
Prince Albert is the third-largest city in Saskatchewan, Canada. It is situated in the centre of the province on the banks of the North Saskatchewan River. The city is known as the "Gateway to the North" because it is the last major centre along the route to the resources of northern Saskatchewan...
, Canada.
Climate
The islands have an Antarctic climate, tempered by their maritime setting. The weather is marked by low seasonal and daily temperature ranges, persistent and generally low cloud cover, frequent precipitation and strong winds. Monthly average temperatures at Atlas Cove (at the northwestern end of Heard Island) range from 0 °C (32 °F) to 4.2 °C (39.6 °F), with an average daily range of 3.7 °C (38.7 °F) to 5.2 °C (41.4 °F) in summer and -0.8 °C to 0.3 °C (32.5 °F) in winter. The winds are predominantly westerly and persistently strong. At Atlas Cove, monthly average wind speeds range between around 26 to 33.5 km/h (16.2 to 20.8 mph). Gusts in excess of 180 km/h (111.8 mph) have been recorded. Annual precipitation at sea level on Heard Island is in the order of 1300 to 1900 mm (51.2 to 74.8 in); rain or snow falls on about 3 out of 4 days.Constraints
The islands are part of the Southern Indian Ocean Islands tundraSouthern Indian Ocean Islands tundra
The Southern Indian Ocean Islands tundra is a tundra ecoregion that includes several subantarctic islands in the southern Indian Ocean.-Location and description:...
ecoregion
Ecoregion
An ecoregion , sometimes called a bioregion, is an ecologically and geographically defined area that is smaller than an ecozone and larger than an ecosystem. Ecoregions cover relatively large areas of land or water, and contain characteristic, geographically distinct assemblages of natural...
that includes several subantarctic
Subantarctic
The Subantarctic is a region in the southern hemisphere, located immediately north of the Antarctic region. This translates roughly to a latitude of between 46° – 60° south of the Equator. The subantarctic region includes many islands in the southern parts of the Indian Ocean, Atlantic Ocean and...
islands. In this cold climate plant life is mainly limited to grasses, moss
Moss
Mosses are small, soft plants that are typically 1–10 cm tall, though some species are much larger. They commonly grow close together in clumps or mats in damp or shady locations. They do not have flowers or seeds, and their simple leaves cover the thin wiry stems...
es and lichen
Lichen
Lichens are composite organisms consisting of a symbiotic organism composed of a fungus with a photosynthetic partner , usually either a green alga or cyanobacterium...
s. Low plant diversity reflects the islands’ isolation, small size, severe climate, the short, cool growing season and, for Heard Island, substantial permanent ice cover. The main environmental determinants of vegetation on subantarctic islands are wind exposure, water availability, parent soil composition, salt spray exposure, nutrient availability, disturbance by trampling (from seabirds and seals) and, possibly, altitude. At Heard Island, exposure to salt spray and the presence of breeding and moulting seabirds and seals are particularly strong influences on vegetation composition and structure in coastal areas.
History
Evidence from microfossil records indicates that ferns and woody plants were present on Heard Island during the TertiaryTertiary
The Tertiary is a deprecated term for a geologic period 65 million to 2.6 million years ago. The Tertiary covered the time span between the superseded Secondary period and the Quaternary...
(a period with a cool and moist climate.) Neither group of plants is present today, although potential Tertiary survivors include the vascular plant Pringlea antiscorbutica and six moss species. Volcanic activity has altered the distribution and abundance of the vegetation. The vascular flora covers a range of environments and, although only six species are currently widespread, glacial retreat and the consequent connection of previously separate ice–free areas is providing opportunities for further distribution of vegetation into adjacent areas.
Flowering plants and ferns
Low-growing herbaceousHerbaceous plant
A herbaceous plant is a plant that has leaves and stems that die down at the end of the growing season to the soil level. They have no persistent woody stem above ground...
flowering plants and bryophyte
Bryophyte
Bryophyte is a traditional name used to refer to all embryophytes that do not have true vascular tissue and are therefore called 'non-vascular plants'. Some bryophytes do have specialized tissues for the transport of water; however since these do not contain lignin, they are not considered to be...
s are the major vegetation components. The vascular flora comprises the smallest number of species of any major subantarctic island group, reflecting its isolation, small ice–free area and severe climate. Twelve vascular species are known from Heard Island, of which five have also been recorded on McDonald Island. None of the vascular species is endemic, although Pringlea antiscorbutica, Colobanthus kerguelensis
Colobanthus kerguelensis
Colobanthus kerguelensis is a low-growing, moss-like flowering cushion plant in the Caryophyllaceae, or carnation family, found on subantarctic islands in the southern Indian Ocean...
, and Poa kerguelensis
Poa kerguelensis
Poa kerguelensis is a species of tussock grass native to various subantarctic islands. The specific epithet refers to the type locality – the Kerguelen Islands.-Description:...
occur only on subantarctic islands in the southern Indian Ocean.
The plants are typically subantarctic, but with a higher abundance of the cushion-forming Azorella selago
Azorella selago
Azorella selago is a species of cushion plant native to the sub-Antarctic islands of the Southern Ocean, including the Crozet Islands, the Possession Islands, the Heard Island and McDonald Islands, the Kerguelen Islands, and the Prince Edward Islands. The closely related Azorella macquariensis,...
than other subantarctic islands. Heard Island is the largest subantarctic island with no confirmed human–introduced plants. Areas available for plant colonisation on Heard Island are generally the result of retreating glaciers or new ice–free land created by lava flows. Today, substantial vegetation covers over 20 km2 of Heard Island, and is best developed on coastal areas at elevations below 250 m.
Mosses, liverworts and lichens
Bryophytes (mosses and liverworts) and lichens contribute substantially to the overall biodiversity of Heard Island, with 43 mosses, 19 liverworts and 71 lichens being recorded, often occupying habitats unsuitable for vascular plants, such as cliff faces. Bryophytes are present in most of the major vegetation communities including several soil and moss-inhabiting species. Lichens are common on exposed rock and dominate the vegetation in some areas. A 1980 survey of McDonald Island found lower diversity than that on Heard Island; four mosses, eight lichens and a number of algal and fungal species are recorded from there.Algae
At least 100 species of terrestrial algae are known from Heard Island, commonly in permanently moist and ephemeral habitats. Forests of the giant Antarctic kelp Durvillaea antarcticaDurvillaea antarctica
Durvillaea antarctica is a large, robust bull kelp species and the dominant seaweed in southern New Zealand and Chile. D. antarctica has a circumpolar distribution between the latitudes of 29°S and 55°S . It is found on exposed shores, especially in the northern parts of its range, and attaches...
occur at a number of sites around Heard Island and at least 17 other species of seaweed are known, with more to be added following the identification of recent collections. Low seaweed diversity is due to the island's isolation from other land masses, unsuitable beach habitat, constant abrasion by waves, tides and small stones, and the extension of glaciers into the sea in many areas.
Vegetation communities
Heard Island has a range of terrestrial environments in which vegetation occurs. Seven general vegetation communities are currently recognised, although vegetation composition is considered more of a continuum than discrete units:- Open cushionfieldCushion plantA cushion plant is a compact, low growing, mat forming plant that is found in alpine, subalpine, arctic, or subarctic environments around the world...
vegetation is the most widespread and abundant vegetation type on Heard Island. It is characterised by Azorella selagoAzorella selagoAzorella selago is a species of cushion plant native to the sub-Antarctic islands of the Southern Ocean, including the Crozet Islands, the Possession Islands, the Heard Island and McDonald Islands, the Kerguelen Islands, and the Prince Edward Islands. The closely related Azorella macquariensis,...
cushions interspersed with bryophytes, small vascular species and bare ground with 20–75% cover, and found mainly at altitudes between 30–70m asl.
- FellfieldFellfieldA fellfield or fell field comprises the environment of a slope, usually alpine or tundra, where the dynamics of frost and of wind give rise to characteristic plant forms in scree interstices.-Soil dynamics:...
describes vegetation with abundant bare ground and less than 50% plant cover. Fellfield may occur as a result of harsh climatic and/or edaphic factors, or recent deglaciation which has exposed bare ground.
- MossMossMosses are small, soft plants that are typically 1–10 cm tall, though some species are much larger. They commonly grow close together in clumps or mats in damp or shady locations. They do not have flowers or seeds, and their simple leaves cover the thin wiry stems...
y fellfieldFellfieldA fellfield or fell field comprises the environment of a slope, usually alpine or tundra, where the dynamics of frost and of wind give rise to characteristic plant forms in scree interstices.-Soil dynamics:...
is a community with high species richness and consists of bryophytes and small Azorella selago cushions. It is found at altitudes between 30–150 m in areas with intermediate exposure.
- Wet mixed herbfieldHerbfieldHerbfields are plant communities dominated by herbaceous plants, especially forbs and grasses. They are found where climatic conditions do not allow large woody plants to grow, such as in subantarctic and alpine tundra environments...
occurs on moist substrate, mostly on moraines and moist lee slopes (often in association with burrowing petrels colonies) at low altitude (< 40 m) where the water table is at or close to the surface. Species richness is highest here of all the communities, with dominant species being Poa cookiiPoa cookiiPoa cookii , sometimes called Cook’s tussock-grass or bluegrass, is a species of tussock grass native to various subantarctic islands...
, Azorella selago, Pringlea antiscorbutica, Acaena magellanicaAcaena magellanicaAcaena magellanica, commonly called Buzzy Burr or Greater Burnet , is a species of flowering plant whose range includes southern South America and many subantarctic islands....
, and Deschampsia antarcticaDeschampsia antarcticaDeschampsia antarctica is one of two flowering plants native to Antarctica, the other being Colobanthus quitensis ....
.
- Coastal bioticCoastal StrandCoastal Strand is a term used to describe a plant community of flowering plants that form along the shore in loose sand just above the high tide line, the on West Coast of the United States.Many plants that grow in this area are endemic to the strand...
vegetation is dominated by Poa cookii and Azorella selago, occurring mainly on coastal sites of moderate exposure and in areas subject to significant influence from seals and seabirds.
- Saltspray vegetationSupralittoral zoneThe supralittoral zone, also known as the splash zone, spray zone or the supratidal zone, is the area above the spring high tide line, on coastlines and estuaries, that is regularly splashed, but not submerged by ocean water...
is dominated by the salt–tolerant moss Muelleriella crassifolia and limited in extent, being found at low elevations on lavas in exposed coastal sites.
- Closed cushionfieldCushion plantA cushion plant is a compact, low growing, mat forming plant that is found in alpine, subalpine, arctic, or subarctic environments around the world...
is found on moraines and sand at altitudes mostly below 60 m, and is dominated almost entirely by Azorella selago cushions that often grow together to form continuous carpets which can be subject to burrowing by seabirds.
Outlook
One of the most rapidly changing physical settings in the subantarctic has been produced on Heard Island by a combination of rapid glacial recession and climate warming. The consequent increase in habitat available for plant colonisation, plus the coalescing of previously discrete ice–free areas, has led to marked changes in the vegetation of Heard Island in the last 20 years or so. Other species and vegetation communities found on subantarctic islands north of the Antarctic ConvergenceAntarctic Convergence
The Antarctic Convergence is a curve continuously encircling Antarctica where cold, northward-flowing Antarctic waters meet the relatively warmer waters of the subantarctic. Antarctic waters predominantly sink beneath subantarctic waters, while associated zones of mixing and upwelling create a zone...
now absent from the Heard Island flora may colonise the island if climate change produces more favourable conditions.
Some plant species are spreading and modifying the structure and composition of communities, some of which are also increasing in distribution. It is likely that further changes will occur, and possibly at an accelerated rate. Changes in population numbers of seal and seabird species are also expected to affect the vegetation by changing nutrient availability and disturbance through trampling.
One plant species on Heard Island, Poa annua
Poa annua
Poa annua, or annual meadow grass , is a widespread low-growing turfgrass in temperate climates. Though P. annua is commonly considered a solely annual plant due to its name, perennial bio-types do exist. 'Poa' is Greek for fodder. It is one of the sweetest grasses for green fodder, but less ...
, a cosmopolitan grass native to Europe, was possibly introduced by humans, though is more likely to have arrived naturally, probably by skua
Skua
The skuas are a group of seabirds with about seven species forming the family Stercorariidae and the genus Stercorarius. The three smaller skuas are called jaegers in North America....
s from the Kerguelen Islands where it is widespread. It was initially recorded in 1987 in two recently deglaciated areas of Heard Island not previously exposed to human visitation, while being absent from known sites of past human habitation. Since 1987 Poa annua populations have increased in density and abundance within the original areas and have expanded beyond them. Expeditioner boot traffic during the Australian Antarctic program expedition in 1987 may be at least partly responsible for the spread, but it is probably mainly due to dispersal by wind and the movement of seabirds and seals around the island.
The potential for introducing additional plant species (including invasive species not previously found on subantarctic islands) by both natural and human–induced means is high. This is due to the combination of low species diversity and climatic amelioration. During the 2003/04 summer a new plant species, Cotula plumosa
Cotula plumosa
Cotula plumosa is a small flowering plant in the daisy family, in a genus the members of which are often called buttonweeds. It is a circumantarctic species found on many subantarctic islands in the Southern Ocean...
, was recorded. Only one small specimen was found growing on a coastal river terrace that had experienced substantial development and expansion of vegetation over the past decade. The species has a circumantarctic distribution and occurs on many subantarctic islands.
Fauna
The main indigenous animals are insects along with large populations of ocean-going seabirdSeabird
Seabirds are birds that have adapted to life within the marine environment. While seabirds vary greatly in lifestyle, behaviour and physiology, they often exhibit striking convergent evolution, as the same environmental problems and feeding niches have resulted in similar adaptations...
s, seals
Pinniped
Pinnipeds or fin-footed mammals are a widely distributed and diverse group of semiaquatic marine mammals comprising the families Odobenidae , Otariidae , and Phocidae .-Overview: Pinnipeds are typically sleek-bodied and barrel-shaped...
and penguin
Penguin
Penguins are a group of aquatic, flightless birds living almost exclusively in the southern hemisphere, especially in Antarctica. Highly adapted for life in the water, penguins have countershaded dark and white plumage, and their wings have become flippers...
s.
Mammals
SealingSeal hunting
Seal hunting, or sealing, is the personal or commercial hunting of seals. The hunt is currently practiced in five countries: Canada, where most of the world's seal hunting takes place, Namibia, the Danish region of Greenland, Norway and Russia...
at Heard Island came to an end in the late 19th century, after the seal populations there had either become locally extinct or reduced to levels too low to exploit economically. Since then the populations have generally increased and are protected. Seals breeding on Heard include the Southern Elephant Seal
Southern Elephant Seal
The Southern Elephant Seal is one of the two extant species of elephant seal. It is both the most massive pinniped and member of the order Carnivora living today...
, the Antarctic Fur Seal
Antarctic Fur Seal
The Antarctic fur seal is one of eight seals in the genus Arctocephalus, and one of nine fur seals in the subfamily Arctocephalinae. As its name suggests, the Antarctic fur seal is distributed in Antarctic waters. Around 95% of the world population breeds at the Island of South Georgia...
and the Subantarctic Fur Seal
Subantarctic Fur Seal
The subantarctic fur seal is a fur seal found in the southern parts of the Indian and Atlantic Oceans. It was first described by Gray in 1872 from a specimen recovered in northern Australia—hence the inappropriate tropicalis specific name.- Description :The subantarctic fur seal is...
. Leopard Seal
Leopard Seal
The leopard seal , also referred to as the sea leopard, is the second largest species of seal in the Antarctic...
s visit regularly in winter to haul-out
Hauling-out
Hauling-out is the behaviour associated with pinnipeds , of temporarily leaving the water between periods of foraging activity for sites on land or ice...
though they do not breed on the islands. Crabeater
Crabeater Seal
The crabeater seal, Lobodon carcinophagus, is a true seal with a circumpolar distribution around the coast of Antarctica. They are medium to large-sized , relatively slender and pale-colored, found primarily on the free floating pack ice that extends seasonally out from the Antarctic coast, which...
, Ross
Ross Seal
The Ross seal is a true seal with a range confined entirely to the pack ice of Antarctica. It is the only species of the genus Ommatophoca. First described during James Clark Ross' British Antarctic Expedition in 1841, it is the smallest, least abundant and least well known of the Antarctic...
and Weddell Seal
Weddell Seal
The Weddell seal , is a relatively large and abundant true seal with a circumpolar distribution surrounding Antarctica. Weddell seals have the most southerly distribution of any mammal, with a habitat that extends as far south as McMurdo Sound...
s are occasional visitors.
Birds
Heard Island and the McDonald Islands are free from introduced predators and provide crucial breeding habitat in the middle of the vast Southern Ocean for a range of birds. The surrounding waters are important feeding areas for birds and some scavenging species also derive sustenance from their co–habitants on the islands.Nineteen species of birds have been recorded as breeding on Heard Island and the McDonald Islands, although recent volcanic activity at the McDonald Islands in the last decade is likely to have reduced vegetated and un–vegetated nesting areas.
Penguins are by far the most abundant birds on the islands, with four breeding species present, comprising King
King Penguin
The King Penguin is the second largest species of penguin at about , second only to the Emperor Penguin. There are two subspecies—A. p. patagonicus and A. p...
, Gentoo
Gentoo penguin
The Gentoo Penguin , Pygoscelis papua, is easily recognized by the wide white stripe extending like a bonnet across the top of its head and its bright orange-red bill. The gentoo penguin has pale whitish-pink webbed feet and a fairly long tail - the most prominent tail of all penguins. Chicks have...
, Macaroni
Macaroni Penguin
The Macaroni Penguin is a species of penguin found from the Subantarctic to the Antarctic Peninsula. One of six species of crested penguin, it is very closely related to the Royal Penguin, and some authorities consider the two to be a single species...
and Eastern Rockhopper Penguin
Eastern Rockhopper Penguin
The Eastern Rockhopper Penguin although genetically differnt is still often considered as a subspecies of the Southern Rockhopper Penguin.-Distribution:...
s. The penguins mostly colonise the coastal tussock and grasslands of Heard Island, and have previously been recorded as occupying the flats and gullies on McDonald Island.
Other seabirds recorded as breeding at Heard Island include three species of albatross (Wandering
Wandering Albatross
The Wandering Albatross, Snowy Albatross or White-winged Albatross, Diomedea exulans, is a large seabird from the family Diomedeidae, which has a circumpolar range in the Southern Ocean. It was the first species of albatross to be described, and was long considered the same species as the Tristan...
, Black–browed
Black-browed Albatross
The Black-browed Albatross or Black-browed Mollymawk, Thalassarche melanophrys, is a large seabird of the albatross family Diomedeidae, and it is the most widespread and common albatross.-Taxonomy:...
and Light-mantled Albatross
Light-mantled Albatross
The Light-mantled Albatross, Phoebetria palpebrata, also known as the Grey-mantled Albatross or the Light-mantled Sooty Albatross, is a small albatross in the genus Phoebetria, which it shares with the Sooty Albatross...
es, Southern Giant Petrel
Southern Giant Petrel
The Southern Giant Petrel , also known as the Antarctic Giant Petrel, Giant Fulmar, Stinker, and Stinkpot, is a large seabird of the southern oceans. Its distribution overlaps broadly with the similar Northern Giant Petrel, though it overall is centered slightly further south...
s, Cape Petrel
Cape Petrel
The Cape Petrel also called Cape Pigeon or Pintado Petrel, is a common seabird of the Southern Ocean from the family Procellariidae. It is the only member of the genus Daption, and is allied to the fulmarine petrels, and the Giant Petrels. It is also sometimes known as the Cape Fulmar...
s, four species of burrowing petrels Antarctic
Antarctic Prion
The Antarctic Prion, Pachyptila desolata, also known as the Dove Prion, or Totorore in Maori, is the largest of the prions, a genus of small petrels of the Southern Ocean.-Taxonomy:...
and Fulmar Prion
Fulmar Prion
The Fulmar Prion, Pachyptila crassirostris, is a species of seabird in the Procellariidae family, found in the southern oceans-Taxonomy:...
s, Common and South Georgian Diving-Petrels), Wilson's Storm-Petrel
Wilson's Storm-petrel
Wilson's Storm Petrel , also known as Wilson's Petrel, is a small seabird of the storm-petrel family. It is one of the most abundant bird species in the world and has a circumpolar distribution mainly in the seas of the southern hemisphere but extending northwards during the summer of the northern...
s, Kelp Gull
Kelp Gull
The Kelp Gull , also known as the Dominican Gull, breeds on coasts and islands through much of the southern hemisphere. The race L. d. vetula occurs around southern Africa, and nominate L. d...
s, Subantarctic Skuas, Antarctic Tern
Antarctic Tern
The Antarctic Tern is a typical tern. It ranges throughout the southern oceans. It is very similar in appearance to the closely related Arctic Tern, but is stockier, and the wing tips are grey instead of blackish in flight...
s and the Heard Shag
Heard Shag
The Heard Island Shag , or Heard Island Cormorant, is a marine cormorant native to the Australian territory comprising the Heard and McDonald Islands in the Southern Ocean, about 4100 km south-west of Perth, Western Australia.-Taxonomy:The Heard Island Shag is one of the blue-eyed shags,...
. Although not a true seabird, the Heard Island subspecies of the Black-faced Sheathbill
Black-faced Sheathbill
The Black-faced Sheathbill , also known as the Lesser Sheathbill or Paddy bird, is one of only two species of sheathbills, aberrant shorebirds which are terrestrial scavengers of subantarctic islands.-Description:...
also breeds on the island. Both the shag and the sheathbill are endemic to Heard Island.
A further 28 seabird species are recorded as non–breeding visitors or from at–sea surveys. All recorded breeding species, other than the Heard Island sheathbill, are listed marine species under the Australian Environmental Protection and Biodiversity Act (1999, four are listed as threatened species and five are listed migratory species. Under the EPBC Act a recovery plan has been made for albatrosses and giant petrels, which calls for ongoing population monitoring of the species found at HIMI, and at the time of preparing this Plan a draft recovery plan has also been made for the Heard Island cormorant and Antarctic tern.
The recorded populations of some seabird species found in the Reserve have shown marked change. The King Penguin population is the best studied seabird species on Heard Island and has shown a dramatic increase since first recorded in 1947/48, with the population doubling every five years or so for more than 50 years.
A paper reviewing population data for the Black–browed Albatross between 1947 and 2000/01 suggested that the breeding population had increased to approximately three times that present in the late 1940s, although a Convention for the Conservation of Antarctic Marine Living Resources CCAMLR) Working Group was cautious about the interpretation of the increasing trend given the disparate nature of the data, as discussed in the paper. The discovery of a large, previously unknown, colony of Heard Shags in 2000/01 at Cape Pillar raised the known breeding population from 200 pairs to over 1000 pairs. On the other hand, the breeding population of Southern Giant Petrels decreased by more than 50% between the early 1950s and the late 1980s.
Terrestrial, freshwater and coastal invertebrates
Heard Island supports a relatively low number of terrestrial invertebrate species compared to other Southern Ocean islands, in parallel with the low species richness in the flora–that is, the island's isolation and limited ice–free area. Endemism is also generally low and the invertebrate fauna is exceptionally pristine with few, if any, (successful) human–induced introductions of alien species.Two species, including the thrip Apterothrips apteris and the mite Tyrophagus putrescentiae are thought to be recent, possibly natural, introductions. An exotic species of earthworm Dendrodrilus rubidus was also collected in 1929 from a dump near Atlas Cove, and has recently been collected from a variety of habitats including wallows, streams and lakes on Heard Island.
The arthropods of Heard Island are comparatively well known with 54 species of mite and tick, one spider and eight springtails recorded. A study over summer at Atlas Cove in 1987/88 showed overall densities of up to 60 000 individual springtails per square metre in soil under stands of Pringlea antiscorbutica. Despite a few recent surveys, the non–arthropod invertebrate fauna of Heard Island remain poorly known.
Beetles and flies dominate Heard Island's known insect fauna, which comprises up to 21 species of ectoparasite (associated with birds and seals) and up to 13 free-living species. Approximately half of the free–living insects are habitat-specific, while the remainder are generalists found in a variety of habitats, being associated with either supralittoral or intertidal zones, Poa cookii and Pringlea antiscorbutica stands, bryophytes, lichen-covered rocks, exposed rock faces or the underside of rocks. There is a pronounced seasonality to the insect fauna, with densities in winter months dropping to a small percentage (between
0.75%) of the summer maximum. Distinct differences in relative abundances of species between habitats has also been shown, including a negative relationship between altitude and body size for Heard Island weevils.
The fauna of the freshwater pools, lakes, streams and mires found in the coastal areas of Heard Island are broadly similar to those on other subantarctic islands of the southern Indian Ocean. Many species reported from Heard Island are found elsewhere. Some sampling of freshwater fauna has been undertaken during recent expeditions and records to date indicate that the freshwater fauna includes a species of Protista, a gastrotrich, two species of tardigrade, at least four species of nematode, 26 species of rotifer, six species of annelid and 14 species of arthropod.
As with the other shore biota, the marine macro-invertebrate fauna of Heard Island is similar in composition and local distribution to other subantarctic islands, although relatively little is known about the Heard Island communities compared with the well-studied fauna of some other islands in the subantarctic region, such as Macquarie
Macquarie Island
Macquarie Island lies in the southwest corner of the Pacific Ocean, about half-way between New Zealand and Antarctica, at 54°30S, 158°57E. 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...
and Kerguelen.
Despite Heard Island's isolation, species richness is considered to be moderate, rather than depauperate, although the number of endemic species reported is low. The large macro-alga Durvillaea antarctica supports a diverse array of invertebrate taxa and may play an important role in transporting some of this fauna to Heard Island.
The rocky shores of Heard Island exhibit a clear demarcation between fauna of the lower kelp holdfast zone and the upper shore zone community, probably due to effects of desiccation, predation and freezing in the higher areas. The limpet Nacella kerguelensis is abundant in the lower part of the shore, being found on rock surfaces and on kelp holdfasts. Other common but less abundant species in this habitat include the chiton Hemiarthrum setulosum and the starfish Anasterias mawsoni. The amphipod Hyale sp. and the isopod Cassidinopsis sp. are closely associated with the kelp. Above the kelp holdfast zone, the littornid Laevilitorina (Corneolitorina) heardensis and the bivalve mollusc Kidderia bicolor are found in well–sheltered situations, and another bivalve Gaimardia trapesina trapesina has been recorded from immediately above the holdfast zone. Oligochaetes are also abundant in areas supporting porous and spongy layers of algal mat.
Wetlands
Heard Island has a number of small wetland sites scattered around its coastal perimeter, including areas of wetland vegetation, lagoons or lagoon complexes, rocky shores and sandy shores, including the Elephant Spit. Many of these wetland areas are separated by active glaciers. There are also several short glacier–fed streams and glacial pools. Some wetland areas have been recorded on McDonald Island but, due to substantial volcanic activity since the last landing was made in 1980, their present extent is unknown.The HIMI wetland is listed on the Directory of Important Wetlands in Australia and, in a recent analysis of Commonwealth–managed wetlands, was ranked highest for nomination under the Convention on Wetlands of International Importance Especially as Waterfowl Habitat (Ramsar Convention) as an internationally important wetland.
Six wetland types have been identified from HIMI covering approximately 1860 ha: coastal ‘pool complex’ (237 ha); inland ‘pool complex’ (105 ha); vegetated seeps mostly on recent glaciated areas (18 ha); glacial lagoons (1103 ha); non-glacial lagoons (97ha); Elephant Spit (300 ha) plus some coastal areas. On Heard Island, the majority of these types suites are found below 150m asl The wetland vegetation occurs in the ‘wet mixed herbfield’ and ‘coastal biotic vegetation’ communities described above.
The wetlands provide important breeding and feeding habitat for a number of Antarctic and subantarctic wetland animals. These include the southern elephant seal and macaroni, gentoo, king and southern rockhopper penguins, considered to be wetland species under the Ramsar Convention. Non–wetland vegetated parts of the islands also support penguin and other seabird colonies.
History
Neither island cluster had recorded visitors until the mid-1850s. Peter Kemp, a British sealer, is the first person thought to have seen the island. On 27 November 1833, he spotted it from the brigBrig
A brig is a sailing vessel with two square-rigged masts. During the Age of Sail, brigs were seen as fast and manoeuvrable and were used as both naval warships and merchant vessels. They were especially popular in the 18th and early 19th centuries...
Magnet during a voyage from Kerguelen to the Antarctic and was believed to have entered the island on his 1833 chart.
An American sealer, Captain John Heard, on the ship Oriental, sighted the island on 25 November 1853, en route from Boston
Boston
Boston is the capital of and largest city in Massachusetts, and is one of the oldest cities in the United States. The largest city in New England, Boston is regarded as the unofficial "Capital of New England" for its economic and cultural impact on the entire New England region. The city proper had...
to Melbourne. He reported the discovery one month later and had the island named after him. Captain William McDonald aboard the Samarang discovered the nearby McDonald Islands six weeks later, on 4 January 1854.
No landing was made on the islands until March 1855, when sealers from the Corinthian, led by Captain Erasmus Darwin Rogers, went ashore at a place called Oil Barrel Point. In the sealing period from 1855 to 1880, a number of American sealers spent a year or more on the island, living in appalling conditions in dark smelly huts, also at Oil Barrel Point. At its peak the community consisted of 200 people. By 1880, most of the seal population had been wiped out and the sealers left the island. In all, more than 100,000 barrels of elephant seal
Elephant seal
Elephant seals are large, oceangoing seals in the genus Mirounga. There are two species: the northern elephant seal and the southern elephant seal . Both were hunted to the brink of extinction by the end of the 19th century, but numbers have since recovered...
oil was produced during this period.
There are a number of wrecks in the vicinity of the islands. There is also a discarded building left from John Heard's sealing station which is situated near Atlas Cove.
The islands have been a territory of Australia since 1947, when they were transferred from the U.K. The archipelago became a World Heritage Site
World Heritage Site
A UNESCO World Heritage Site is a place that is listed by the UNESCO as of special cultural or physical significance...
in 1997.
Administration and economy
The United Kingdom formally established its claim to Heard Island in 1910, marked by the raising of the Union Jack and the erection of a beacon by Captain Evensen, master of the Mangoro. Effective government, administration and control of HeardIsland and the McDonald Islands was transferred to the Australian government on 26 December 1947 at the commencement of the first Australian National Antarctic Research Expedition (ANARE) to Heard Island, with a formal declaration that took
place at Atlas Cove. The transfer was confirmed by an exchange of letters between the two governments on 19 December 1950.
The islands are a territory (Territory of Heard Island and McDonald Islands) of Australia administered from Hobart
Hobart
Hobart is the state capital and most populous city of the Australian island state of Tasmania. Founded in 1804 as a penal colony,Hobart is Australia's second oldest capital city after Sydney. In 2009, the city had a greater area population of approximately 212,019. A resident of Hobart is known as...
by the Australian Antarctic Division
Australian Antarctic Division
The Australian Antarctic Division is an agency of the Department of Sustainability, Environment, Water, Population and Communities . The division undertakes science programs and research projects to contribute to an understanding of Antarctica and the Southern Ocean...
of the Australian Department of the Environment and Water Resources. They are populated by large numbers of seal and bird species. The islands are contained within a 65000 square kilometres (25,096.6 sq mi) marine reserve and are primarily visited for research. There is no permanent human habitation.
From 1947 until 1955 there were camps of visiting scientists on Heard Island (at Atlas Cove
Atlas Cove
Atlas Cove is a cove on the north coast of Heard Island in the southern Indian Ocean, and is entered between the base of Laurens Peninsula and Rogers Head. It was named by American sealers after the schooner sealing fleet which landed at Heard Island in 1855...
in the northwest, which was in 1969 again occupied by American scientists and expanded in 1971 by French scientists) and in 1971 on McDonald Island (at Williams Bay). Later expeditions used a temporary base at Spit Bay
Spit Bay
Spit Bay is an open bight formed by the northeast coastline of Heard Island and Spit Point, the east extremity of the island. The name derives from the conspicuous Elephant Spit which forms the south and east shore of the bight, and may have been given by American sealers at Heard Island in the...
in the northeast, such as in 1988, 1992–93 and 2004–05.
With no population, there is no indigenous economic activity. The islands' only natural resource is fish; the Australian government allows limited fishing in the surrounding waters. Despite the lack of population, the islands have been assigned the country code
Country code
Country codes are short alphabetic or numeric geographical codes developed to represent countries and dependent areas, for use in data processing and communications. Several different systems have been developed to do this. The best known of these is ISO 3166-1...
HM in ISO 3166-1
ISO 3166-1
ISO 3166-1 is part of the ISO 3166 standard published by the International Organization for Standardization , and defines codes for the names of countries, dependent territories, and special areas of geographical interest. The official name of the standard is Codes for the representation of names...
(ISO 3166-2:HM
ISO 3166-2:HM
ISO 3166-2:HM is the entry for Heard Island and McDonald Islands in ISO 3166-2, part of the ISO 3166 standard published by the International Organization for Standardization , which defines codes for the names of the principal subdivisions of all countries coded in ISO 3166-1.Currently no ISO...
) and therefore the Internet top-level domain
Top-level domain
A top-level domain is one of the domains at the highest level in the hierarchical Domain Name System of the Internet. The top-level domain names are installed in the root zone of the name space. For all domains in lower levels, it is the last part of the domain name, that is, the last label of a...
.hm
.hm
.hm is the Internet country code top-level domain for the Heard and McDonald Islands, an uninhabited territory of Australia.There has been limited use of this top-level domain, most of it unrelated in any way to the Heard and McDonald Islands. For instance, my.hm issues firstname.lastname.hm in a...
. The timezone of the islands is UTC+5.
See also
- Australian Antarctic TerritoryAustralian Antarctic TerritoryThe Australian Antarctic Territory is a part of Antarctica. It was claimed by the United Kingdom and placed under the authority of the Commonwealth of Australia in 1933. It is the largest territory of Antarctica claimed by any nation...
- Birds of Heard and McDonald Islands
- List of islands of Australia
- List of Antarctic islands north of 60° S
- List of sub-Antarctic islands
Further reading
- Scholes, Arthur. (1949) Fourteen men; story of the Australian Antarctic Expedition to Heard Island. Melbourne: F.W. Cheshire.
- Smith, Jeremy. (1986) Specks in the Southern Ocean. Armidale: University of New England Press. ISBN 0-85834-615-X
- Green, Ken and Woehler Eric. (2006) Heard Island: Southern Ocean Sentinel. Chipping Norton: Surrey Beatty and Sons.
- Australian Government. (2005) "Heard Island and McDonald Islands Marine Reserve Management Plan". Australian Antarctic Division: Kingston (Tas). ISBN 1 876 93408 5.
External links
- Click here to see a map of Heard Island and McDonald Islands, including all major topographical features
- Heard Island and McDonald Islands official website
- World heritage listing for Heard Island and McDonald Islands
- Image gallery of Heard Island and McDonald Island with high quality limited copyright images.
- MODIS satellite image, taken 30 September 2004 and showing a von KármánTheodore von KarmanTheodore von Kármán was a Hungarian-American mathematician, aerospace engineer and physicist who was active primarily in the fields of aeronautics and astronautics. He is responsible for many key advances in aerodynamics, notably his work on supersonic and hypersonic airflow characterization...
vortex streetVon Kármán vortex streetA Kármán vortex street is a term in fluid dynamics for a repeating pattern of swirling vortices caused by the unsteady separation of flow of a fluid over bluff bodies...
in the clouds, caused by Mawson Peak's effect on the wind - UNESCO World Heritage site entry
- Fan's page with further historical and geographic information and a map