History | World Heritage Criteria 1 | 2 | 3 | 4

How Hinchinbrook Island meets World Heritage Criterion:

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  These figures indicate that this section of coastline is a major feeding ground for dugongs (Marsh 1992, unpublished data).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 Wilderness Lodge), 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.

PO Box 3
Cardwell
Queensland
Australia 4849