Shark Bay

Template:Short description Template:Use Australian English Template:Use dmy dates {{#invoke:other uses|otheruses}} Template:Infobox UNESCO World Heritage Site

File:Shark Bay SPOT 1188.jpg

Louis Henri de Saulces de Freycinet's Useless Harbour in Shark Bay, seen from the SPOT satellite

File:Shark Bay.svg

Map of Shark Bay area

File:Zuytdorp Cliffs.jpg

Zuytdorp Cliffs

Shark Bay (Template:Langx) is a World Heritage Site in the Gascoyne region of Western Australia. The Template:Convert<ref name=auto>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> area is located approximately Template:Convert north of Perth, on the westernmost point of the Australian continent.

UNESCO's listing of Shark Bay as a World Heritage Site reads:<ref name=whl>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>

Shark Bay's waters, islands and peninsulas....have a number of exceptional natural features, including one of the largest and most diverse seagrass beds in the world. However, it is for its stromatolites (colonies of microbial mats that form hard, dome-shaped deposits which are said to be the oldest life forms on earth), that the property is most renowned. The property is also famous for its rich marine life including a large population of dugongs, and provides a refuge for a number of other globally threatened species.{{#if:|{{#if:|}}
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The bay features Australia's most abundant marine ecosystems.<ref name="sbl">Template:Cite news</ref> It is a popular fishing spot.

HistoryEdit

The record of Australian Aboriginal occupation of Shark Bay extends to 22,000 years BP. At that time most of the area was dry land, and rising sea levels flooded Shark Bay between 8,000 BP and 6,000 BP. A considerable number of Aboriginal midden sites have been found, especially on Peron Peninsula and Dirk Hartog Island, which provide evidence of some of the foods gathered from the waters and nearby land areas.<ref name=whl />

An expedition led by Dirk Hartog happened upon the area in 1616, becoming the second group of Europeans known to have visited Australia, after the crew of Duyfken under Willem Janszoon had visited Cape York in 1606. The area was given the name Shark Bay by the English explorer William Dampier,<ref>Template:Cite Q</ref> on 7 August 1699.<ref>Template:Cite book</ref> Shark Bay was also visited by Louis Aleno de St Aloüarn in 1772, Nicolas Baudin from 1801 to 1803 and Louis de Freycinet in 1818.<ref name="wha"/> Europeans, mostly pastoralists, settled in Shark Bay during the 1860s to 1870s.<ref name="wha"/> Pearling developed rapidly from 1870.<ref name="wha"/>

Commercial whaling was conducted in the bay in the first half of the 20th century by Norwegian-owned factory ships and their catcher vessels.<ref>Template:Cite book</ref> In the late 1930s, up to 1,000 humpback whales were taken per season.

The heritage-listed area had a population of fewer than 1,000 people as at the 2011 census. The half-dozen small communities making up this population occupy less than 1% of the total area.

ClimateEdit

The Shark Bay Heritage Area has a hot desert climate under the Köppen Climate Classification, with hot, dry summers, and very mild, relatively wet winters.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>

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Shark Bay World Heritage SiteEdit

The World Heritage status of the region was created and negotiated in 1991,<ref>Template:Cite book</ref> the first such site in Western Australia.<ref name="wha">Template:Cite journal</ref> The site was gazetted on the Australian National Heritage List on 21 May 2007<ref name=auto/> under the Environment and Heritage Legislation Amendment Act (No. 1), 2003.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>

Protected areasEdit

Declared as a World Heritage Site in 1991, the site covers an area of Template:Convert, of which about 70 per cent are marine waters. It includes many protected areas and conservation reserves, including Shark Bay Marine Park, Francois Peron National Park, Hamelin Pool Marine Nature Reserve, Zuytdorp Nature Reserve and numerous protected islands.<ref name=whl /> Denham and Useless Loop both fall within the boundary of the site, yet are specifically excluded from it.

LandformsEdit

The bay itself covers an area of Template:Convert, with an average depth of Template:Convert.<ref name=whl /> It is divided by shallow banks and has many peninsulas and islands. The coastline is over Template:Convert long. There are about Template:Convert of limestone cliffs overlooking the bay.<ref name="natstr" /> One spectacular segment of cliffs is known as the Zuytdorp Cliffs. The bay is located in the transition zone between three major climatic regions and between two major botanical provinces.

Peron Peninsula divides the bay and is the home of its largest settlements as well as a National Park at the northern end.

Dirk Hartog Island is of historical significance due to landings upon it by early explorers. In 1616, Dirk Hartog landed at Inscription Point on the north end of the island and marked his discovery with a pewter plate, inscribed with the date and nailed to a post. This plate was then replaced by Willem de Vlamingh and returned to the Netherlands. It is now kept in the Rijksmuseum. The Shark Bay Discovery Centre in Denham has a replica of this plate.

Bernier and Dorre islands in the north-west corner of the heritage area are among the last-remaining habitats of two varieties of Australian mammals, hare-wallabies, threatened with extinction.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> They are used, with numerous other smaller islands throughout the marine park, to release threatened species that are being bred at Project Eden in François Peron National Park. These islands are free of feral non-native animals which might predate upon the threatened species, and so provide a safe haven in which to restore species that are threatened on the mainland.

In 1999 the Australian Wildlife Conservancy acquired the Template:Convert pastoral lease over Faure Island, off Monkey Mia. Sea turtles nest there seasonally and are the subject of studies conducted in conjunction with the Department of Biodiversity, Conservation and Attractions.<ref>Template:Cite journal</ref>

FaunaEdit

Shark Bay is an area of major zoological importance. It is home to about 10,000 dugongs ('sea cows'), around 12.5% of the world's population,<ref name="natstr">Template:Cite book</ref> and there are many Indo-Pacific bottlenose dolphins, particularly at Monkey Mia. The dolphins here have been particularly friendly since the 1960s.<ref name="natstr" /> The area supports 26 threatened Australian mammal species, over 230 species of bird, and nearly 150 species of reptile. It is an important breeding and nursery ground for fish, crustaceans, and coelenterates. There are over 323 fish species, many of them sharks and rays.

Some bottlenose dolphins in Shark Bay exhibit one of the few known cases of tool use in marine mammals (along with sea otters): they protect their nose with a sponge while foraging for food in the sandy sea bottom. Humpback and southern right whales use the waters of the bay as migratory staging post<ref name="natstr" /> while other species such as Bryde's whale come into the bay less frequently but to feed or rest. The threatened green and loggerhead sea turtles nest on the bay's sandy beaches. The largest fish in the world, the whale shark, gathers in the bay during the April and May full moons.<ref name="natstr" />

FloraEdit

Shark Bay has the largest known area of seagrass, with seagrass meadows covering over Template:Convert of the bay.<ref name=auto/> It includes the Template:Convert Wooramel Seagrass Bank, the largest seagrass bank in the world<ref name=auto/> and contains a Template:Convert Posidonia australis meadow formed by a single plant, the largest in the world.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>

Shark Bay also contains the largest number of seagrass species ever recorded in one place; twelve species have been found, with up to nine occurring together in some places. The seagrasses are a vital part of the complex environment of the bay. Over thousands of years, sediment and shell fragments have accumulated in the seagrasses to form vast expanses of seagrass beds. This has raised the sea floor, making the bay shallower. Seagrasses are the basis of the food chain in Shark Bay, providing home and shelter to various marine species and attracting the dugong population.

In Shark Bay's hot, dry climate, evaporation greatly exceeds the annual precipitation rate. Thus, the seawater in the shallow bays becomes very salt-concentrated, or hypersaline. Seagrasses also restrict the tidal flow of waters through the bay area, preventing the ocean tides from diluting the sea water. The water of the bay is 1.5 to 2 times more salty than the surrounding ocean waters.

File:Stromatolites in Shark Bay.jpg

Stromatolites in Hamelin Pool are ancient structures that are built by microbes.

StromatolitesEdit

Based on growth rate it is believed that about 1,000 years ago cyanobacteria (blue-green algae) began building up stromatolites in Hamelin Pool at the Hamelin Station Reserve in the southern part of the bay.<ref>Template:Cite book</ref><ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref><ref name=Chivas>Template:Cite journal</ref> These microbialites, a type of sedimentary structure, are modern examples of some of the earliest signs of life on Earth,<ref>Template:Cite book</ref> with fossilized stromatolites being found dating from 3.5Template:Nbspbillion years ago at North Pole near Marble Bar, in Western Australia, and are considered the type of fossil with the longest continuous presence in the geological record.<ref name="natstr" /> Shark Bay's modern examples were first identified in 1956 at Hamelin Pool, before that only being known in the fossil record. They may, however, be significantly different from fossilised examples, as growth rates may be up to 250 times slower than the estimated growth rates of some Precambrian stromatolites. There is debate, however, over whether this indicates a true difference in growth rate, or if Precambrian growth estimates are instead too high.<ref name=Chivas/> Hamelin Pool contains the most diverse and abundant examples of living stromatolite forms in the world. Other occurrences are found at Lake Clifton near Mandurah and Lake Thetis near Cervantes.<ref name=auto/> It is hypothesized that some stromatolites contain a new form of chlorophyll, chlorophyll f.<ref>Template:Cite press release</ref>

Shark Bay World Heritage Discovery CentreEdit

Facilities around the World Heritage area, provided by the Shire of Shark Bay and the Department of Biodiversity, Conservation and Attractions, include the Shark Bay World Heritage Discovery Centre in Denham which provides interactive displays and comprehensive information about the features of the region.

AccessEdit

Access to Shark Bay is by air via Shark Bay Airport, and by the World Heritage Drive, a Template:Convert link road between Denham and the Overlander Roadhouse on the North West Coastal Highway.

Specific reserved areasEdit

National parks and reserves in the World Heritage AreaEdit

File:A143, Shark Bay Marine Park, Western Australia, dolphin, 2007.JPG

Dolphin at Monkey Mia

File:A226, Shark Bay Marine Park, Western Australia, Shell Beach, 2007.JPG

Shell Beach

Bays of the World Heritage areaEdit

Islands of the World Heritage areaEdit

Peninsulas of the World Heritage areaEdit

IBRA sub regions of the Shark Bay AreaEdit

The Shark Bay area has three bioregions within the Interim Biogeographic Regionalisation for Australia (IBRA) system: Carnarvon, Geraldton Sandplains, and Yalgoo. The bioregions are further divided into sub-bioregions:<ref>Template:Cite book</ref>

Carnarvon bioregion (CAR) –
- Wooramel sub region (CAR2) – most of Peron Peninsula and coastline east of Hamelin Pool
- Cape Range sub region (CAR1) – (not represented in area)
Geraldton Sandplains bioregion (GS) –
- Geraldton Hills sub region (GS1) – Zuytdorp Nature Reserve area
- Leseur sub region (GS2) – (not represented in area)
Yalgoo bioregion (YAL) –
- Tallering sub region (YAL2) (not represented in area)
- Edel subregion (YAL1) – Bernier, Dorre and Dirk Hartog Islands