|List||World Heritage List|
|Legal Status||Declared property (13/12/1991)|
|Place File No||5/14/193/0013|
|Statement of Significance|
Shark Bay is located
on the most western point of the coast of Australia and covers an area of 2.3
million hectares. The region is one of the few properties inscribed on the
World Heritage List for all four outstanding natural universal values:
The number of species that reach the end of their range is a major feature of the region's flora. Twenty-five per cent of vascular plants (283 species) are at the limits of their range in Shark Bay. Many vegetation formations and plant species are found only in the interzone area.
The area south of Freycinet Estuary contains the unique type of vegetation known as tree heath. There are also at least 51 species endemic to the region and others that are considered new to science.
The Shark Bay region is an area of major zoological importance, primarily due to habitats on peninsulas and islands being isolated from the disturbance that has occurred elsewhere. Of the 26 species of endangered Australian mammals, five are found on Bernier and Dorre Islands. These are the boodie or burrowing bettong, rufous hare wallaby, banded hare wallaby, the Shark Bay mouse and the western barred bandicoot.
The Shark Bay region has a rich avifauna with over 230 species, or 35 per cent, of Australia's bird species having been recorded. A number of birds attain their northern limit here, such as the regent parrot, western yellow robin, blue-breasted fairy wren and striated pardalote.
The region is also noted for the diversity of its amphibians and reptiles, supporting nearly 100 species. Again, many species are at the northern or southern limit of their range. The area is also significant for the variety of burrowing species, such as the sandhill frog, which, apparently, needs no surface water. Shark Bay contains three endemic sand swimming skinks, and 10 of the 30 dragon lizard species found in Australia.
The 12 species of seagrass in Shark Bay make it one of the most diverse seagrass assemblages in the world. Seagrass covers over 4 000 square kilometres of the bay, with the 1 030 square kilometre Wooramel Seagrass Bank being the largest structure of its type in the world.
Seagrass has contributed significantly to the evolution of Shark Bay as it has modified the physical, chemical and biological environment as well as the geology and has led to the development of major marine features, such as Faure Sill.
The barrier banks associated with the growth of seagrass over the last 5 000 years has, with low rainfall, high evaporation and low tidal flushing, produced the hypersaline Hamelin Pool and Lharidon Bight. This hypersaline condition is conducive to the growth of cyanobacteria which trap and bind sediment to produce a variety of mats and structures including stromatolites.
Stromatolites represent the oldest form of life on earth. They are representative of life-forms some 3 500 million years ago. Hamelin Pool contains the most diverse and abundant examples of stromatolite forms in the world.
Shark Bay is renowned for its marine fauna. The population of about 10 000 dugong, for example, is one of the largest in the world, and dolphins abound, particularly at Monkey Mia.
Humpback whales use the Bay as a staging post in their migration along the coast. This species was reduced by past exploitation from an estimated population of 20 000 on the west coast to 500-800 whales in 1962; the population is now estimated at 2 000-3 000.
Green and loggerhead turtles are found in Shark Bay near their southern limits, nesting on the beaches of Dirk Hartog Island and Peron Peninsula. Dirk Hartog Island is the most important nesting site for loggerhead turtles in Western Australia.
Shark Bay is also an important nursery ground for larval stages of crustaceans, fishes and medusae.
Shark Bay is a large, shallow bay with associated peninsulas
and islands on the coast of WA. The place, which has a total area of
22,000sqkm, includes the marine and estuarine areas of the bay, together with the
peninsulas and islands projecting into it and adjacent areas of the mainland
including the coastal strip along the eastern coast and the region immediately
to the south. Shark Bay is part of the Carnarvon Basin which includes
predominantly Cretaceous and Tertiary sandstones and limestones, overlain in
parts by siliceous dune systems. There are Quaternary deposits of sediments
from the Gascoyne and Worramel Rivers in coastal areas between Carnarvon and
Yaringa. Sediments in the bay itself are almost exclusively the result of
biological, chemical and physical processes operating within the bay rather
than from deposition of land derived sediments. A large beach ridge shell
deposit is located in the vicinity of Hamelin Pool and Lharidon Bight. The
Faure Sill, a sedimentary bank formed across the entrance of Hamelin Pool, is
derived from sediment accretions in seagrass meadows and is of relatively
recent origin (approximately 4,000 years bp). The Zuytdorp Cliffs in the west
are associated with a Quaternary fault line. Gypsum filled hollows (birridas)
formed during times of higher groundwater tables occur throughout the region.
Shark Bay consists of a series of north-south trending peninsulas and islands
which separate inlets and bays from each other and the Indian Ocean. The place
comprises three distinct landscape types: the Gascoyne-Wooramel Province, a low
lying plain backed by a limestone escarpment, forms a coastal strip to the east
of the bay; Peron Province, which comprises undulating sandy plains interspersed
with gypsum pans and terminating seaward in a scarp to 30m height, includes
Nanga and Peron Peninsulas and Faure Island; Edel Province is a landscape of
elongate north trending dunes terminating in steep cliffs to the west and
including Edel Land Peninsula and Dirk Hartog, Bernier and Dorre Islands. The
internal coastline (1,500km) of the bay includes a diversity of landscape
features ranging from ocean cliffs to rocky platforms to shallow bays and sandy
beaches. The terrestrial landscape includes low rolling hills interspersed with
gypsum filled pans. The marine areas comprise a large, shallow embayment of
about 13,000sqkm, with an average depth of 9m. The bay is enclosed by Bernier,
Dorre and Dirk Hartog Islands to the west and includes a series of gulfs,
narrow inlets and basins which project into the bay in a north-westerly
direction. Seawater influx to the bay occurs principally via channels between
the islands, resulting in a restricted circulation. Inflow of freshwater into
the bay from the Wooramel and Gascoyne Rivers is intermittent and runoff influx
is small. The semi-arid climate of the area, the low runoff and the
semi-enclosed nature of inlets and gulfs of the bay result in restricted tidal
flushing and increased salinities, particularly in the northern and western
parts of the bay. More extreme hypersaline conditions typically occur in the
southern parts associated with Lharidon Bight and Hamelin Pool where the Faure
Sill prevents outflow of denser saline waters produced by evaporation. Salinity
gradients in the bay range from sea water (35 to 40 parts per thousand) in the
northern and western parts of the bay to metahaline (40 to 56 parts per
thousand), to hypersaline (56 to 70 parts per thousand) in the Hamelin Pool and
Lharidon Bight. The salinity gradient has created three biotic zones that have
a marked effect on the distribution of the marine organisms in the bay. Shark
Bay includes a large range of vegetation types and species associated with the
diversity of environments and habitats which occur in the place. The
terrestrial vegetation of the place typically includes low shrublands, herb
fields and grasslands. The South West Botanical Province has vegetation rich in
eucalyptus species, forming forests and woodlands with diverse, shrubby
understoreys and heathlands, but with few grasses. In contrast, the Eremaean
Province is rich in acacia species but has large areas of grassland,
particularly dominated by hummock grasses belonging to the genera triodia and
pelectrachne. The transition from one botanical province to the other is near
the Denham Road, crossing the road near the southern end of the Peron
Peninsula. The main part of the South West Botanical Province is at its
northern limit on an area of red sandplain on Nanga Station. The sandplain has
a complex of vegetation types dominated by low trees and tall shrubs of the
genera EUCALYPTUS, LAMARCHEA, CALOTHAMNUS, GREVILLEA and EREMAEA and with
understoreys of HAKEA, CALYTRIX, BAECKEA, SCHOLTZIA, GREVILLEA, PITYRODIA and
MELALEUCA species. This vegetation complex is the most species rich in the
place and includes many species at their northern limit of distribution and
many endemic species. The rest of the Peron Peninsula has two Eremaean
vegetation types, one characterised by the endemic Hummock Grass, TRIODIA
plurinervaia and the other by a tall wattle species, ACACIA RAMULOSA, which
occurs in association with other wattles, especially A SCLEROSPERMA and A.
TETRAGONOPHYLLA. Other vegetation on Peron Peninsula includes heaths and shrublands
on recent coastal dunes and halophytic vegetation on coastal flats and small
salt lakes (birridas). Two vegetation types dominate the area from Tamal
Homestead to the coast and along Edel Land, including a vegetation type largely
on calcareous soils and dominated by atriplex species and another type on dunes
and dune swales dominated by melaleuca and acacia species. Specialised
vegetation types on the mainland include the limestone cliff vegetation on the
west coast of Edel Land which is subject to salt spray and areas of mangroves
on protected bay coasts. (Also see individual listings for the following
registered places: Peron Nanga Area; Edel Land; Bernier and Dorre Islands;
Small Islands, Shark Bay; Dirk Hartog Island; Denham Sound, Freycinet Reach and
Estuary, Hopeless Reach and Lharidon Bight, Shark Bay; Wooramel Seagrass Bank;
and Hamelin Pool and Faure Sill|
|History Not Available|
|Condition and Integrity Not Available|
About 2,197,300ha, surrounding Denham, comprising the Shark
Bay World Heritage Area as defined in Appendix 4 of the Agreement between the
State of Western Australia and the Commonwealth of Australia on Administrative
Arrangements for the Shark Bay World Heritage Property, signed on 12 September
Figgis, P. and Mosley, G. (1988) Australia's
Weldon Publishing, Sydney. |
Western Australia. Department of Conservation and Land Management 1(1989) Shark Bay Como, WADCLM
Trugden, M. (1995) Flora of Shark Bay World Heritage Area and its Environs Como, WADCLM.
Report Produced Sat Dec 14 07:01:21 2013