|List||World Heritage List|
|Legal Status||Declared property (17/12/1982)|
|Place File No||1/00/373/0001|
|Statement of Significance|
The Lord Howe Island
Group was inscribed on the World Heritage List for its outstanding natural
Nearly seven million years ago geologic movement of the Lord Howe Rise (an underwater plateau) gave birth to a large shield volcano on its western edge. Over time the sea eroded 90 per cent of the original volcano, leaving the islands that today comprise the Lord Howe Island Group.
Lord Howe Island has a spectacular landscape with the volcanic mountains of Mount Gower (875 m) and Mount Lidgbird (777 m) towering above the sea. The central low-lying area provides a marked contrast to the adjacent mountains and northern hills.
There are 241 different species of native plants, of which 105 are endemic to Lord Howe Island. Most of the island is dominated by rainforests and palm forest. Grasslands occur on the more exposed areas of Lord Howe Island and on the offshore islands. Most of the main island and all of the offshore islands are included in the Lord Howe Island Permanent Park Preserve.
The islands support extensive colonies of nesting seabirds and at least 168 bird species have been recorded either living at, or visiting, the islands. A number of these are rare or endangered.
The endangered woodhen is one of the world's rarest bird species. During this century the population of woodhens experienced a significant decline in numbers as a result of hunting by humans, habitat loss and disturbance by feral animals. Over the last few years a successful captive breeding program and other conservation measures have increased the numbers of these small flightless birds to around 220.
The islands are one of two known breeding areas for the providence petrel, a species that is also found nesting on Phillip Island, near Norfolk Island. They also contain probably the largest breeding concentration in the world of the red-tailed tropicbird, and the most southerly breeding colony of the masked booby.
The waters surrounding Lord Howe Island provide an unusual mixture of temperate and tropical organisms. The reef is the southern most coral reef in the world and provides a rare example of the transition between coral and algal reefs. A marine national park was declared by the State of New South Wales in 1999 to increase protection of the marine environment.
Europeans apparently discovered Lord Howe Island when the island was sighted in 1788 from the British colonial naval vessel HMS Supply, en route from Sydney to the penal colony on Norfolk Island. The first landing was made two months later on the return voyage to Sydney.
By the 1830s there was a small permanent settlement in the lowland area of the main island. The settlers made a living by hunting and fishing, and by growing vegetables, fruit and meat for trade with passing ships.
Pigs and goats, which were introduced to Lord Howe Island for food, later went wild and caused extensive vegetation and habitat changes, threatening populations of native species. Rats arrived on the island in 1918 from a wrecked ship, and have since been responsible for the extinction of five bird species. Over the last decade there have been intensive efforts to control these feral animals and the wild pigs have been successfully eradicated.
Lord Howe Island and its associated islands are under the care, control and management of the Lord Howe Island Board. When carrying out its functions, the Board is required to have particular regard to the World Heritage status of the area and to conserve those values for which the area was listed as a World Heritage property.
The main island
of Lord Howe measures
10km from north and south and is little more than 2km in width. It roughly
describes a crescent, enclosing a coral reef lagoon on its south-western side.
The island's topography is dominated by the southerly Mount
Gower (875m) and Mount Lidgbird
(777m). Steep cliffs rise several hundred metres to
form theseaward flanks of Mount Gower.
Only a narrow isthmus of lowland country in the north-central part of the
island is habitable. The northern tip consists of steep hillsides culminating
in extensive sea cliffs against the northern coastline. Scattered around the
main island are several groups of smaller islands and rocks. The most distant
of these is a group of small islets and rock stacks around the 650m pinnacle of
Balls Pyramid, 25km to the south-east of Lord Howe. |
Lord Howe Island is the eroded remnant of a large shield volcano which erupted from the sea floor intermittently for about 500,000 years, 6.5 to 7 million years ago in the late Miocene (McDougall et al., 1981). The island group represents the exposed peaks of a large volcanic seamount which is about 65km long and 24km wide and which rises from ocean depths of over 1,800m. The Lord Howe seamount is near the southern end of a chain of such seamounts, mostly below sea level, extending for over 1,000km. These mark the successive movement of the Australian tectonic plate over a 'hotspot' within the upper mantle below. Four separate series of volcanic rocks are recognised on the main island group, the oldest being exposed in the Admiralty Group and on the north-eastern tip of Lord Howe. These include tuffs, breccia and basalts, with widespread intrusion of basaltic dykes, and are overlain by progressively younger units to the south (Davey, 1986). The youngest volcanic rock is Mt Lidgbird basalt, which is present in lava flows up to 30m thick. Sedimentary aeolian calcarenite or dune limestone characterise the lowland parts of the main island (Davey, 1986).
The dominant landforming process on Lord Howe since the last of the volcanic eruptions has been marine erosion, which has cut and maintained major cliffs. Slope failure and accumulation of talus at the foot of some cliffs, especially in the south, have modified their original shape. Local variations in lithology are the major determinant of the shape of the irregular rocky coastline and of the small residual islands and rock stacks. There are numerous resistant projecting points and sea caves (Davey, 1986).
Subsequent erosion means that the present islands occupy only one-fortieth of the original area. Lord Howe Island has sedimentary deposits of Pleistocene and Holocene (Recent) age, including cross-bedded calcarenite with intercalated soil horizons, lagoonal deposits, a single sand dune, and alluvium. The island supports the southernmost true coral reef in the world, which is of Pleistocene to Recent age and differs considerably from more northerly warm water reefs. It is unique in being a transition between the algal and coral reef, due to fluctuations of hot and cold water around the island. The entire island group has remarkable volcanic exposures not known elsewhere, with slightly weathered exposed volcanics showing a great variety of upper mantle and oceanic type basalts. Ball's Pyramid represents the nearly complete stage in the destruction of a volcanic island. The intercalated soil horizons have yielded important palaeontological data, with interesting fossil finds such as the shells of land snail Placostylus and the terrestrial giant horned turtle Meiolania platyceps, which probably became extinct more than 20,000 years ago. A fossil bat skull, uncovered in 1972, has been described as a new species Nyctophilus howensis; it may have persisted into modern times. Significant landforms in the preserve are listed in Davey (1986).
Climate is humid subtropical with a mean temperature of 16 degrees C in August and 23 degrees C in February. Both diurnal and seasonal temperature range is about 7 degrees C. A temperature of 0 degrees C has been recorded on the summit of Mount Gower. Mean annual rainfall in the lowlands isalmost 1700mm, with a pronounced maximum in winter and a mean rainfall of 100mm in February. The highest annual rainfall recorded in the lowlands is 2870mm, with a minimum of 1000mm. The southerly part of Lord Howe Island is generally wetter due to orographic effects. Relative humidity is high at 75-78% and wind levels average 13 knots in August, 9-10 knots in January and March. Climatic data and summaries are available in Anon. (1969), Gentilli (1971), Pickard (1983) and Rodd (1981).
A wide variety of vegetation types has been described for the islands, with the diversity corresponding with the range of habitats, viz. lowland, montane, valleys, ridges and areas exposed to the maritime influence. Variable exposure to wind and penetration of salt spray appear to be the main determinants of vegetation occurrence, structure and floristics. Lord Howe Island is almost unique among small Pacific Ocean islands in that its mountains have sufficient altitude for the development of true cloud forest on their summits. These are 241 native species of vascular plants on the island, including 105 endemics (DEST/ERIN (1995). Sixteen of these are considered rare, endangered or vulnerable. There are four endemic palm species in three endemic genera. There are also two other endemic genera in the families Asteraceae and Gesneriaceae. Other endemic species are widely scattered among families. Endemism is particularly noticeable among ferns and in the families Asteraceae, Myrsinaceae, Myrtaceae and Rubiaceae. There are 48 species of indigenous pteriodphytes (including 19 endemic ferns) belonging to 32 genera, and 180 species of angiosperms (56 endemics) in 149 genera. A further four species are represented by endemic subspecies or varieties; there are no gymnosperms. Some of the endemics suggest recent speciation, and many have confusing origins, such as the three endemic palm genera Howea, Hedyscope and Lepidorrhachis, and also Dietes sp., the three congeners of which are endemic to southern Africa and which has seeds with apparently only short range dispersal capacity. Other noteworthy endemics are Dendrobium moorei and Bubbia howeana. Many species are threatened or have restricted distribution on the island; there is only one known plant of non-endemic Pandanus pedunculatus, and Chionochloa conspicua ssp. nov. (Poaceae) is an endemic known only from one clump on Mount Lidgbird.
The vegetation has affinities with sub-tropical and temperate rain forests, and 129 plant genera are shared with Australia, 102 with New Caledonia and only 75 with New Zealand. There are 160 naturalised, introduced plant species, mostly, but not exclusively, in the lowland settlement area. Weed species of the greatest immediate concern within the preserve are bone seed (biton bush), kikuya grass (Davey, 1986) and asparagus fern Protoasparagus eathiopicus (Lord Howe Island Board in litt., August 1995). Many other species are potentially serious problems (Davey, 1986).
Twenty-five vegetation associations in twenty alliances have been identified (Pickard, 1983). Fourteen of these associations have endemic species as their dominant components. The slopes of the northern hills are dominated mostly by Drypetes/Cryptocaria rain forest, with Howea forsterana palm forest on the flats behind North Bay and H. belmoreana palm forest in the narrower gullies running down towards Old Settlement Beach. Melaleuca/Cassinia scrubs and Cyperus and Poa grasslands occur on the exposed slopes of Mount Eliza and along the crest of the sea cliffs on the northern coast. The southern mountains are covered with a more variable suite of rain forest and palm associations, often with Pandanus along drainage lines, and with scrub and cliff associations in the more exposed parts and along the coastline. Mutton Bird Point(on the east coast) and King Point (at the southern tip) have small occurrences of Poa grassland. The upper slopes of mounts Gower and Lidgbird include areas of forest dominated by another of the endemic palms, Hedyscepe canterburyana. The very humid summit plateau on Gower and the summit ridge on Lidgbird consist of structurally distinct gnarled mossy forest (Davey, 1986).
A small population of little cave eptesicus Eptesicus sagittula still occurs. No other indigenous native mammals are known. Introduced species, however, include mouse Mus musculus and rats Muridae, goat Capra hircus and, formerly, pig Sus domestica.
There are at least 129 native and introduced bird species, mostly vagrants, with 27 breeding regularly. A partial species list is given in Davey (1986). Lord Howe is now the only known breeding ground for providence petrel Pterodroma solandri, although it also probably breeds on Ball's Pyramid. Fleshy-footed shearwater Puffinus carneipes hullianus breeds in substantial numbers on Lord Howe, with possibly half the world's population present. Other important species breeding within the preserve include Kermadec petrel Pterodroma neglecta, black-winged petrel P. nigripennis, wedge-tailed shearwater Puffinus pacificus, little shearwater P. assimilis, white-bellied storm petrel Fregetta grallaria, masked booby Sula dactylatra, red-tailed tropic bird Phaeton rubricauda in greater concentrations than probably anywhere else in the world. Sooty tern Sterna fuscata, noddy Anous stolidus and grey ternlet Procelsterna cerula. Several migratory wader species are regular visitors to the island, principally are double-banded dotterel Charadrius bicinctus, eastern golden plover Pluvialis dominica, turnstone Arenaria interpres, whimbrel Numenius phaeopus and bar-tailed godwit Limosa lapponica. Four endemic birds are present. Lord Howe Island woodhen Tricholimnas sylvestris, reduced to some 26 individuals in 1975, has been successfully bred in captivity and now numbers around 220 (DEST/ERIN, 1995). The other endemic land birds are silver-eye Zosterops tephropleura, Lord Howe Island golden whistler Pachycephala pectoralis contempta, both reasonably abundant(Davey, 1986). The Lord Howe Island currawong Strepera graculina crissalis is relatively common in the southern mountains, with lesser number found in the north (Lord Howe Island Board, in litt., August 1995).
The islands support two species of terrestrial reptile, skink Leiolopisma lichenigera and gecko Phyllodactylus guentheri, which are threatened with extinction on the main island but are abundant on other islands in the group. Many of the endemic invertebrates from the moss forest on the summit of Mount Gower have been collected and described. The small terrestrial gastropods (Hydrobiidae) comprises nine species and sixteen subspecies, a greater number of subspecies than those found on the eastern Australian mainland. The terrestrial molluscs have suffered from habitat changes; two colonies of large ground snails Placostylus sp. appear to be maintaining their numbers, though distinct forms seem to have become extinct on other parts of the island. There are five endemic species of flies (Diptera) and a further nine confined to Lord Howe and Norfolk Islands. Specimens of Lord Howe Island phasmid Dryococoelus australis (Ex), a large flightless phasmatid thought to be extinct on Lord Howe Island, is known to occur still on Ball's Pyramid. Over 50% of more than 100 species of spiders recorded for Lord Howe Island are thought to be endemic. One endemic species of leech and ten endemic species of earthworm have also been recorded. The terrestrial and freshwater crustacea are not well known, but include a freshwater crab Halicarcinus lacustris and a freshwater prawn Paratya howensis. Three new genera and 12 new species of terrestrial isopod have been recorded and recently anew species of talitrid amphipod from the top of Mount Gower was described. The waters around Lord Howe Island provide an unusual mixture of temperate and tropical organisms, 477 fish species having been recorded in 107 families of which 4% are unrecorded elsewhere other than in Norfolk Island-Middleton Reef waters. Lionfish Pterois volitans is protected in the marine waters (ANPWS, 1981).
The earliest European discovery of Lord Howe appears to have been in 1788 by the British colonial vessel HMS Supply. There is no recognised evidence of prior Polynesian or Melanesian discovery or settlement. A small permanent settlement was established in the 19th century, subsisting on trade with passing ships. With numerous fluctuations over the years, the settlement slowly expanded and consolidated, developing a distinctive social structure and culture with the passage of time (Davey, 1986). The island is an interesting example of restricted island settlement, although the World Heritage nomination was not made on cultural grounds (ANPWS, 1981).
There is currently a resident population of approximately 300 individuals inhabiting the relatively level ground in the central part of the main island. Tourism is the major component of the island economy, followed by public administration and community service. Approximately 10% of the main island's vegetation has been cleared for agriculture, and another 10% has been subject to physical disturbance. Commercial activities within the preserve include collection of palm seed, especially Kentia palm Howea forsterana and cutting of Pandanus foliage for production of baskets and other craft items, subject to control by the Lord Howe Island Board (Davey, 1986).
|Condition and Integrity Not Available|
About 152000ha, 700km north-east of Sydney, being an area bounded by the
following latitude and longitude co-ordinates: |
Latitude: 31 degrees 25 minutes S – 31 degrees 50 minutes S
Longitude: 159 degrees E – 159 degrees 20 minutes E
Included are Lord Howe Island and adjacent islets, Admiralty Islands, Mutton Bird Islands, Ball’s Pyramid, and associated coral reefs and marine environ.
Burbidge, A. A. and
Jenkins, R. W. G. (1984) Endangered Vertebrates of Australia and its Island
Territories ANPWS, Canberra. |
Hutton, I. (1986) Lord Howe Island Conservation Press, Canberra
Hutton, I. (1998) The Australian Geographic Book of Lord Howe Island, Australian Geographic.
Miller, B. and Kingston, T. (1980) Lord Howe Island Woodhen'in Endangered Species of New South Wales, National Parks and Wildlife Service.
Pickard, J. (1983) Vegetation of Lord Howe Island in Cunninghamia 1(2), pp133-266.
Report Produced Sat Dec 21 07:01:39 2013