Hinchinbrook Island World Heritage

Rainforest

The Hinchinbrook area has perhaps a unique distinction as a place twice worthy of World Heritage Listing.

The highly successful conservation convention, known as the 'Convention Concerning the Protection of the World Cultural and Natural Heritage' commonly know as the "World Heritage Convention" began as a UNESCO agreement in 1972. It came into force with the sufficient level of ratifications in 1974 and achieved substance in 1978 with the inscription of the first four natural sites on the World Heritage List. By 1994 there were 137 signatories and 110 natural or mixed natural sites. Australia was the seventh country to lodge its ratification in August 1974 and in 1981 had its first three nominations inscribed on the World Heritage List (Kakadu National Park, Willandra Lakes and the Great Barrier Reef)

A World Heritage Site must meet one or more of the following criteria:

  • be outstanding examples representing major stages of the earth's history, including the record of life, significant on-going process in the development of landforms, or significant geomorphic or physiographic features.
  • be an outstanding example representing significant on-going ecological and biological processes in the evolution and development of terrestrial, freshwater, coastal and marine ecosystems and communities of plants and animals.
  • contain superlative natural phenomena or areas of exceptional natural beauty and aesthetic importance.
  • contain the most important and significant natural habitats for in situ conservation of biological diversity, including those containing threatened species of outstanding universal value from the point of view of science or conservation.

Summary of World Heritage Values of Hinchinbrook Island

  • geological and geomorphologic process and features of Hinchinbrook Island and Channel
  • the high diversity of Brook Island coral reefs and their outstanding scenic properties
  • the visual splendour and outstanding diversity of the mangrove communities of Hinchinbrook Island and Channel
  • the extremely high floristic diversity of Hinchinbrook Island lowlands
  • the critical habitat of seagrasses and associated threatened marine animals
  • the present high levels of integrity associated with the site

How Hinchinbrook Island meets World Heritage Criterion

Criteria 1

Orchid Beach

be outstanding examples representing major stages of the earth's history, including the record of life, significant on-going process in the development of landforms, or significant geomorphic or physiographic features

The Hinchinbrook Area includes an exceptional collection of interrelated elements form the mangrove communities, active sand dune process, coastal lowlands through a very wide range of biological communities to a peak altitude of 1142 metres (Mt Bowen). All of these are very close to their natural condition and provide a rare opportunity to stay that way.

The mountain, gorge and waterfall landscape of the Hinchinbrook Area is the result ,in the Australian context, the result of relatively recent uplift of the earth's crust. The common summit level of Hinchinbrook Island is also a vestige of an older dissected surface uplifted to approximately 1000 metres or more above sea level. Seen from almost any viewpoint, the spectacular profile of Hinchinbrook Island is clearly very special.

The main mass of Hinchinbrook Island and the coastal rangers are comprised of 260 million year old Almaden Granites. These rocks formed deep below the surface where they cooled slowly to form large-grained crystals.

Hinchinbrook Passage is thought to be fault controlled, with the Island and ranges being thrust up as blocks and subsidence occurring in between to form the coastal plain. Hinchinbrook Island has had dry land connections to the mainland for most of the past few million years and was separated from the mainland by a shallow, narrow water barrier only at times of high sea-level such as present.

The dune systems at Ramsay Bay, on the east coast of Hinchinbrook Island provide further evidence of former sea level oscillation and geomorphologic processes.. Two major periods of dune building have been dated for the periods 9500-6000 years BP and within the last 900 years.

Fossilised crabs, include a species of Fiddler Crab (6000 years old) are found in the creeks of the Island and on the shore of Ramsay Bay. There are only two other places (Southern California and the Panama Canal) in the world where fossilised fiddler crabs have been found.

The Brook Island reefs contain in excess of half the coral species recorded from the entire Great Barrier Reef.. The Brook Island fringe reefs are of high quality supporting diverse coral communities comprised of over 200 reef-building species (approximately two-thirds of the species of hard coral found on the GBR ) and including large colonies of a variety of species, several of which are amount the largest of their species yet reported. These corals are the tropical marine equivalents of emergent rainforest tress both in terms of their age, which are likely to be in the order of several hundred years, and in terms of the provision of habitat for other species. These Brook Island corals include some of the larges and presumably oldest yet found anywhere on earth. Such large corals play a significant role as "seed stock" in recolonisation of nearby disturbed areas.

Criteria 2

Sunset

be an outstanding example representing significant on-going ecological and biological processes in the evolution and development of terrestrial, freshwater, coastal and marine ecosystems and communities of plants and animals.

A 1989 survey of tropical lowlands between Ingham to Cooktown indicate that Hinchinbrook Island and Channel National Parks are of outstanding importance because of the diversity of rare communities.

Mangroves: Hinchinbrook Island, Channel and the adjacent mainland support one of the larges occurrences of mangroves along the "Wet Tropics" coastline. This area represents the largest, richest and most divers mangrove habitat in Australia. There are at least 30 species represented in these forests.

Other Vegetation Communities: The area between Cardwell and the Cardwell range contains by far the best remaining Melaleuca forest home of the mahogany glider (thought to be extinct), at least two endangered species of orchids, and endangered species of "ant plant" (Myrmecodia beccarii) and the rare apollo jewel butterfly (Hypochrysops apollo apollo) the larvae of which lives on the ant plants. The association between these ant plant, butterflies and the ant species which occupiers the galleries of the plant provide a classical example of symbiotic mutualism.

Orchids: Fifteen terrestrial orchids have been recorded in the broad-leafed Melaleuca viridiflora forests and a further eight species in the mixed eucalyptus forests of the region. The ground orchids Genoplesium tectium and Arthrochilus stenophyllus are also endemic to the Hinchinbrook Region. The endangered species Phais tankervillaea is found behind the beach at Zoe Bay on the east coast of the Island.

Criteria 3

contain superlative natural phenomena or areas of exceptional natural beauty and aesthetic importance.

"Hinchinbrook Island is one of Queensland's best known national parks and is also the largest of the State's island parks. It contains a divers array of flora, fauna, habitat types and geological formations. In particular it is important for the length of undeveloped coastline- a scarce commodity in the rapidly developing Wet Tropics Region of North Queensland. But above all Hinchinbrook Island is known for scenery. The rugged, often cloud-covered peaks are a spectacular feature seen by all travellers on the Bruce Highway between Ingham and Cardwell. The scenery of Hinchinbrook Channel is nothing short of awe-inspiring."(GW Mercer Regional Director Queensland Department of Environment and Heritage in the Forward to the draft Hinchinbrook Island Management Plan 1994).

Hinchinbrook Island was included in the Wet Tropics Study conducted by the Rainforest Conservation Society of Queensland 1986 not only because of its important vegetation, especially its mangrove forests, but also because of its magnificent scenery. With and are of 395 square kilometres, it is the largest island in the wet tropics.... The difficult climb to the summit of Mount Bowen provides magnificent views of the white sandy beaches of the Pacific Ocean to the east, the unique almost parallel tidal channel of the mangrove systems of Missionary Bay to the north and the winding channels of the mangroves of Hinchinbrook Channel to the west" Hinchinbrook is indeed a unique "passage landscape" one of only four such passage systems in Australia.

Criteria 4

contain the most important and significant natural habitats for in situ conservation of biological diversity, including those containing threatened species of outstanding universal value from the point of view of science or conservation.

"With an area of 39350 ha, Hinchinbrook Island National Park is Australia's largest island national park and one of the largest island nation parks in the world.... It provides a unique opportunity to set aside an area in the Wet Tropics region of North Queensland where natural communities from sea level to 1000 metres can be preserved in something very close to their natural condition" (QDEH 1994)

Seagrasses: Hinchinbrook Channel has the second highest biomass of seagrass in the Central Section of the Great Barrier Reef. Seagrasses play a part i9n stabilising shallow mudflats and help maintain the productivity of coastal waters. However the most important role of seagrasses is that they are essential food for dugongs and sea turtles and an important habitat for the juveniles of a number of prawn species. The herbivorous dugong graze on the seagrasses Holadule uninervis, Holadule pinifola and Halophila ovalis. Of recent significance is the identification of the seagrass Halophila tricostata in the Hinchinbrook Channel. This species of seagrass is not normally associated with shallow inshore waters.

Dugongs: "Dugongs are vulnerable because of their low rate of reproduction and because their association with shallow inshore habitats brings them into contact with human activities... The rate of population change is most sensitive to changes in survivorship. Even a slight reduction in adult survivorship can result in a chronic decline in dugong population" (Marsh et al. 1992)

Major feeding places observed, in the northern end of Hinchinbrook Channel are Hecate Point and offshore from Cardwell. In 1992 aerial surveys recorded six dugongs in the Hinchinbrook Channel. The population in the channel was estimated to be 141 +/- 89 mammals. In comparison, offshore from Hinchinbrook Island two dugongs were sighted. The offshore population estate is 257 +/- 105. These figures indicate that this section of coastline is a major feeding ground for dugongs (Marsh 1992, unpublished data). the error figures also indicate the large uncertainty about population numbers, hence the need for extreme caution in management

Dolphins: The Irrawaddy (river dolphin) is known to occur in tropical and subtropical coastal waters in some of the major river systems of the Indo-West Pacific region from the Bay of Bengal to the east Australian coast and between 25 degrees latitude north and south of the equator. The Irrawaddy dolphin is interim listed as vulnerable by the Queensland National Parks and Wildlife Service (Thompson, pers. comm 1993). It is not know how important the Hinchinbrook Areas is to the species.

The Indo-Pacific Hump-back dolphin (Sousa chinensis) is typically found in tropical inshore waters, estuaries and tidal reaches of rivers. It frequents mangrove regions and its distribution apparently coincides with that of mangroves (Klinowska 1991) This species can be found in mixed schools with bottlenose dolphins. The hump-back dolphin is interim listed as rare by the Queensland National Parks and Wildlife Service.

The Bottlenose dolphin (Tursiops truncatusI is found worldwide in tropical and temperate waters, both inshore and offshore. The inshore varieties have a range that includes river moths, bays, lagoons, estuaries and shallow coastal waters to a depth of 20m. The population estimates for Bottlenose dolphins in the Channel is 1288 +/- 428 whereas the population offshore from Hinchinbrook Island is 29 +/- 20 (Marsh 1992 unpublished data)

Sea Turtles The Australian Heritage Commission notes the significance of Hinchinbrook Channel and surrounding waters as a home to sea turtles. (AHC 1993) Sea turtles have been sighted near more seagrass meadows in the Hinchinbrook Channel than in any other management area in the Central Section of the Great Barrier reef Marine Park.

Large numbers of turtles are associated with extensive sea grass beds in the northern par of Hinchinbrook Channel. Turtle "nests" and tracks have been seen on the beach at Ramsay Bay on the western side of Missionary Bay, and on the Brook Islands (Thorsborne & Thorsborne 1988) The Green turtle (Chelonia mydas) is herbivorous and is frequently seen grazing on seagrasses in the Channel. Loggerhead turtles (Caretta caretta) and Flatback turtles (Chelonia depressa) also frequently seen in the Channel. The Hawksbill and Pacific Ridley turtles are seen occasionally.

All species of sea turtles are listed as endangered by the International Union for the Conservation of Nature.

"...green turtles are endangered because their long life cycle and their association with shallow inshore habitats brings them into contact with human activities. The rate of population change is very sensitive to changes in adult survivorship. As a result, population models suggest that maximising survivorship of sea turtles on their benthic feeding grounds is very important for their conservation." Crose (1987).

The Queensland National Parks and Wildlife Service have been investigating population declines of the loggerhead turtles for many years and record that the, population has declined by at least 50% in the last 11 years. The population decline is still in progress. The Queensland rookeries are the breeding sites for most of the loggerhead turtles of the South Pacific (Limpus et al. ca1990). Hence, protectionmust be afforded to nesting sites, feeding grounds and waters that these migratory species follow>

Population estimates for the turtles in the Hinchinbrook area are 429 +/- 96 turtles inside the Channel and 2376 +/- 463 in waters outside the Channel (Marsh 1992).

Estuarine Crocodiles: The estuarine crocodile (Crocodylus poosus), otherwise known as the saltwater crocodile, has its prime habitat in coastal mangrove swamps and freshwater lagoons. saltwater crocodiles have been depleted in most other countries that Australia could now be considered a potential source of stock for the species. The mangrove swamps of Hinchinbrook Channel are an important habitat for the estuarine crocodile. Crocodiles breed in the estuaries of Gayundah, Paluma, Mendal Creeks and Deluge Inlet on the western side of Hinchinbrook Island (QDEH 1994).

Fish and Crustaceans:In a study of seagrass beds and fish nurseries between Cairns and Bowen (Coles et al. 1989) the highest number of fish species was recorded in Hinchinbrook channel, which also had the second highest fish species diversity. The highest number of crab species and the highest crab species diversity index were also recorded in the Hinchinbrook Channel.

Birds: The area shares some of the rich bird diversity of the wet tropics but there is a special focus on some species. Torresian Imperial Pigeons The Brook Islands, five nautical miles east of Hinchinbrook's Cape Richards (Site of the Hinchinbrook Island Resort), have a particular significance as host to a colony of over 30,000 Torres Strait Pigeons (Ducula spilorrhoa formerly Myristicivora spilorrhoa) or nutmeg pigeons. This is the largest nesting colony for tghe pigeons in the southern part of their range.

Beach thick-knees (Burhinus neglectus), which nest on the beaches of Hinchinbrook Island, are regarded as vulnerable (Australian Nature conservation Agency). These beach nesting birds have come under threat on the mainland due to heavy demands humans have put on coastal resources and becase of predation by introduced animals.