Shark Bay

{{Short description|Bay of the Indian Ocean in Western Australia}}

{{Use Australian English|date=April 2013}}

{{Use dmy dates|date=August 2022}}

{{other uses}}

{{Infobox UNESCO World Heritage Site

| WHS = Shark Bay, Western Australia

| image = Shark Bay Phytoplankton in Bloom.jpg

| caption = Shark Bay

| Location = Gascoyne region, Western Australia, Australia

| Criteria = Natural: vii, viii, ix, x

| ID = 578

| Coordinates = {{coord|25|30|S|113|30|E|type:waterbody_scale:1500000_region:AU-WA|display=inline,title}}

| Year = 1991

| Area = {{cvt|2,200,902|ha}}

| locmapin = Australia

| map_caption = Location of Shark Bay at the most westerly point of the Australian continent

| map_width = 280

| relief = 1

}}

File:Shark Bay SPOT 1188.jpg]]

File:Shark Bay.svg

File:Zuytdorp Cliffs.jpg]]

Shark Bay ({{langx|vml|Gathaagudu|lit=two waters}}) is a World Heritage Site in the Gascoyne region of Western Australia. The {{convert|23000|km2|adj=on}}{{cite web |last1=Johns |first1=Angela |title=World Heritage Places - Shark Bay, Western Australia |url=https://www.dcceew.gov.au/parks-heritage/heritage/places/world/shark-bay |publisher=Department of Climate Change, Energy, the Environment and Water |access-date=6 June 2024 |location=Canberra |date=16 April 2024}} area is located approximately {{convert|800|km}} north of Perth, on the westernmost point of the Australian continent.

UNESCO's listing of Shark Bay as a World Heritage Site reads:{{cite web |url=https://whc.unesco.org/en/list/578|title=Shark Bay, Western Australia|website=World Heritage Convention|publisher= UNESCO World Heritage Centre |date=2014 |access-date=30 August 2014 |archive-url=https://web.archive.org/web/20140803191019/https://whc.unesco.org/en/list/578/ |archive-date=3 August 2014|url-status=live}}

{{blockquote |text=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.}}

The bay features Australia's most abundant marine ecosystems.{{cite news |last1=Prendergast |first1=Joanna |last2=Lewis |first2=Chris |date=13 May 2023 |title=Shark Bay locals fear influx of fishers to World Heritage site will harm fish stocks |url=https://www.abc.net.au/news/2023-05-13/fears-for-fish-in-shark-bay-world-heritage-marine-site/102271510 |work=ABC News |access-date=8 November 2023}} It is a popular fishing spot.

History

The record of Australian Aboriginal occupation of Shark Bay extends to {{formatnum:22000}} years BP. At that time most of the area was dry land, and rising sea levels flooded Shark Bay between {{formatnum:8000}} BP and {{formatnum:6000}} 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.

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,{{cite Q |Q126680180 |mode=cs1}} on 7 August 1699.{{cite book |last1=Burney |first1=James|author-link1=James Burney |title=A Chronological History of the Discoveries in the South Sea or Pacific Ocean |chapter=7. Voyage of Captain William Dampier, in the Roebuck, to New Holland |volume=4|publisher=G. & W. Nicol, G. & J. Robinson & T. Payne|year=1803|location=London|page=395 |chapter-url=https://books.google.com/books?id=1DhAAAAAYAAJ&q=James+Burney&pg=PR12|access-date=9 October 2013}} 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. Europeans, mostly pastoralists, settled in Shark Bay during the 1860s to 1870s. Pearling developed rapidly from 1870.

Commercial whaling was conducted in the bay in the first half of the 20th century by Norwegian-owned factory ships and their catcher vessels.{{cite book |last1=Brown |first1=Peter Lancaster |title=Australia's coast of coral and pearl |date=1995 |publisher=Seal Books |location=Sydney |page=16}} In the late 1930s, up to 1,000 humpback whales were taken per season.

The heritage-listed area had a population of fewer than {{formatnum:1000}} people as at the 2011 census. The half-dozen small communities making up this population occupy less than 1% of the total area.

Climate

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.{{cite web |url = http://www.bom.gov.au/climate/averages/tables/cw_006105_All.shtml|title = Shark Bay Airport Climate Statistics|publisher = Bureau of Meteorology |access-date = April 1, 2024

}}

{{Weather box

|metric first= Y

|single line= Y

|location= Shark Bay Airport (25º53'S, 113º35'E, 34 m AMSL) (2004-2020 normals and extremes)

|Jan record high C= 47.3

|Feb record high C= 49.8

|Mar record high C= 47.2

|Apr record high C= 39.9

|May record high C= 37.0

|Jun record high C= 30.7

|Jul record high C= 30.3

|Aug record high C= 35.6

|Sep record high C= 36.7

|Oct record high C= 42.8

|Nov record high C= 44.8

|Dec record high C= 46.2

|Jan high C= 34.1

|Feb high C= 34.9

|Mar high C= 34.2

|Apr high C= 31.0

|May high C= 27.5

|Jun high C= 23.8

|Jul high C= 22.9

|Aug high C= 24.2

|Sep high C= 26.1

|Oct high C= 28.4

|Nov high C= 30.4

|Dec high C= 32.5

|Jan low C= 21.6

|Feb low C= 22.3

|Mar low C= 21.4

|Apr low C= 18.3

|May low C= 14.5

|Jun low C= 11.7

|Jul low C= 10.6

|Aug low C= 11.2

|Sep low C= 12.8

|Oct low C= 15.4

|Nov low C= 17.7

|Dec low C= 19.8

|Jan record low C= 16.3

|Feb record low C= 16.5

|Mar record low C= 13.8

|Apr record low C= 10.0

|May record low C= 4.5

|Jun record low C= 3.7

|Jul record low C= 2.8

|Aug record low C= 5.0

|Sep record low C= 6.2

|Oct record low C= 7.6

|Nov record low C= 10.3

|Dec record low C= 13.2

|precipitation colour= green

|Jan precipitation mm= 6.7

|Feb precipitation mm= 24.5

|Mar precipitation mm= 16.3

|Apr precipitation mm= 10.3

|May precipitation mm= 23.1

|Jun precipitation mm= 42.3

|Jul precipitation mm= 28.6

|Aug precipitation mm= 19.3

|Sep precipitation mm= 8.1

|Oct precipitation mm= 4.6

|Nov precipitation mm= 2.1

|Dec precipitation mm= 7.1

|unit precipitation days = 1.0 mm

|Jan precipitation days = 0.7

|Feb precipitation days = 1.2

|Mar precipitation days = 0.9

|Apr precipitation days = 1.1

|May precipitation days = 2.8

|Jun precipitation days = 4.3

|Jul precipitation days = 4.1

|Aug precipitation days = 3.1

|Sep precipitation days = 2.0

|Oct precipitation days = 1.2

|Nov precipitation days = 0.5

|Dec precipitation days = 0.3

|Jan humidity= 43

|Feb humidity= 43

|Mar humidity= 38

|Apr humidity= 41

|May humidity= 40

|Jun humidity= 42

|Jul humidity= 43

|Aug humidity= 39

|Sep humidity= 40

|Oct humidity= 41

|Nov humidity= 41

|Dec humidity= 41

|Jan dew point C = 16.7

|Feb dew point C = 17.4

|Mar dew point C = 14.6

|Apr dew point C = 13.1

|May dew point C = 10.1

|Jun dew point C = 8.1

|Jul dew point C = 7.7

|Aug dew point C = 6.9

|Sep dew point C = 8.3

|Oct dew point C = 10.4

|Nov dew point C = 12.3

|Dec dew point C = 14.1

|source 1 = Bureau of Meteorology{{cite web

|url = http://www.bom.gov.au/climate/averages/tables/cw_006105_All.shtml

|title = Shark Bay Airport Climate Statistics

|publisher = Bureau of Meteorology

|access-date = April 1, 2024

}}

}}

Shark Bay World Heritage Site

The World Heritage status of the region was created and negotiated in 1991,{{cite book|title=Agreement between the state of Western Australia and the Commonwealth of Australia on administrative arrangements for the Shark Bay World Heritage Property in Western Australia|location=Perth, W.A. |publisher=WA Department of Conservation and Land Management |date=12 September 1997}} the first such site in Western Australia.{{cite journal |last1=Christensen |first1=Joseph |last2=Jones |first2=Roy |date=February 2020 |title=World Heritage and local change: Conflict, transformation and scale at Shark Bay, Western Australia |url=https://www.sciencedirect.com/science/article/abs/pii/S074301671830384X |journal=Journal of Rural Studies |volume=74 |pages=235–243 |doi=10.1016/j.jrurstud.2019.11.017 |bibcode=2020JRurS..74..235C |s2cid=213680094 |access-date=29 October 2022|url-access=subscription }} The site was gazetted on the Australian National Heritage List on 21 May 2007 under the Environment and Heritage Legislation Amendment Act (No. 1), 2003.{{cite web|url=http://www.environment.gov.au/system/files/pages/758ea283-6b9d-41bc-a29a-1276e1c7fced/files/10568601.pdf|type=PDF|title=Determination regarding including World Heritage places in the National Heritage List|work=Special government gazette|number=S.99|date=21 May 2007|access-date=30 August 2014|publisher=Department of the Environment and Water Resources, Commonwealth of Australia|archive-url=https://web.archive.org/web/20140903135629/http://www.environment.gov.au/system/files/pages/758ea283-6b9d-41bc-a29a-1276e1c7fced/files/10568601.pdf|archive-date=3 September 2014|url-status=live}}

= Protected areas =

Declared as a World Heritage Site in 1991, the site covers an area of {{convert|23000|km2}}, 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. Denham and Useless Loop both fall within the boundary of the site, yet are specifically excluded from it.

= Landforms =

The bay itself covers an area of {{convert|1300000|ha|acre}}, with an average depth of {{convert|9|m}}. It is divided by shallow banks and has many peninsulas and islands. The coastline is over {{convert|1500|km}} long. There are about {{convert|300|km}} of limestone cliffs overlooking the bay. 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.{{Cite web |title=Banded Hare-wallaby |url=https://www.australianwildlife.org/wildlife/banded-hare-wallaby/ |access-date=2022-06-05 |website=AWC – Australian Wildlife Conservancy |language=en-AU}} 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 {{convert|5,816|ha|adj=on}} 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.{{cite journal |last1=Algar |first1=David |last2=Angus |first2=Gary John |title=Feasibility study for the eradication of feral cats from Faure Island, Shark Bay, Western Australia |journal=WA Museum Records and Supplements |date=2008 |volume=75 |issue=75 |page=71 |doi=10.18195/issn.0313-122x.75.2008.071-075 |url=https://museum.wa.gov.au/research/records-supplements/records/feasibility-study-eradication-feral-cats-faure-island-shark-bay |access-date=6 June 2024}}

= Fauna =

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,{{cite book |title=Nature's Strongholds: The World's Great Wildlife Reserves |last=Riley |first=Laura and William |year=2005 |publisher=Princeton University Press |location=Princeton, New Jersey |isbn=0-691-12219-9 |pages=595–596 |url=https://books.google.com/books?id=icMuBQhW4vgC |access-date=12 July 2011}} and there are many Indo-Pacific bottlenose dolphins, particularly at Monkey Mia. The dolphins here have been particularly friendly since the 1960s. 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 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.

= Flora =

Shark Bay has the largest known area of seagrass, with seagrass meadows covering over {{convert|4000|km2}} of the bay. It includes the {{convert|1030|km2|adj=on}} Wooramel Seagrass Bank, the largest seagrass bank in the world and contains a {{convert|200|km2|adj=on}} Posidonia australis meadow formed by a single plant, the largest in the world.{{cite web|first1=Graham |last1=Readfearn | url=https://www.theguardian.com/environment/2022/jun/01/what-the-hell-australian-scientists-discover-biggest-plant-on-earth-off-wa-coast | title=Scientists discover 'biggest plant on Earth' off Western Australian coast | website=The Guardian|location=London |access-date=6 June 2024 | date=1 June 2022 }}

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.jpgs in Hamelin Pool are ancient structures that are built by microbes.]]

= Stromatolites =

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.{{cite book|last1=Giusfredi|first1=Paige E.|access-date=3 November 2014|title=Hamelin Pool Stromatolites: Ages and Interactions with the Depositional Environment|date=22 July 2014|publisher=University of Miami|location=Miami, FL|url=http://scholarlyrepository.miami.edu/oa_theses/501/|archive-url=https://web.archive.org/web/20141105113203/http://scholarlyrepository.miami.edu/oa_theses/501/|archive-date=5 November 2014|url-status=live}}{{cite web|url=http://www.sharkbay.org/Stromatolitesfactsheet.aspx|title=Stromatolites of Shark Bay: Nature fact sheets|work=WA Department of Environment and Conservation|publisher=Government of Western Australia|access-date=3 September 2011|archive-url=https://web.archive.org/web/20111109022625/http://www.sharkbay.org/Stromatolitesfactsheet.aspx|archive-date=9 November 2011|url-status=live}}{{Cite journal |last1=Chivas |first1=A. R. |last2=Torgersen |first2=T. |last3=Polach |first3=H. A. |date=1990-06-01 |title=Growth rates and Holocene development of stromatolites from Shark Bay, Western Australia |url=https://www.tandfonline.com/doi/full/10.1080/08120099008727913 |journal=Australian Journal of Earth Sciences |language=en |volume=37 |issue=2 |pages=113–121 |doi=10.1080/08120099008727913 |bibcode=1990AuJES..37..113C |issn=0812-0099|url-access=subscription }} These microbialites, a type of sedimentary structure, are modern examples of some of the earliest signs of life on Earth,{{Cite book |last=Nichols |first=Gary |title=Sedimentology and stratigraphy |date=2010 |publisher=Wiley-Blackwell |isbn=978-1-4051-3592-4 |edition=2. ed., [Nachdr.] |location=Chichester}} with fossilized stromatolites being found dating from 3.5{{nbsp}}billion 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. 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. 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. It is hypothesized that some stromatolites contain a new form of chlorophyll, chlorophyll f.{{cite press release|author=Avolio C.|url=http://sydney.edu.au/news/science/397.html?newsstoryid=5479|title=First new chlorophyll in 60 years discovered|publisher=Faculty of Science, The University of Sydney|date=20 August 2010|access-date=25 August 2011|archive-url=https://web.archive.org/web/20121012090602/http://sydney.edu.au/news/science/397.html?newsstoryid=5479|archive-date=12 October 2012|url-status=live}}

= Shark Bay World Heritage Discovery Centre =

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.

= Access =

Access to Shark Bay is by air via Shark Bay Airport, and by the World Heritage Drive, a {{convert|150|km|adj=on}} link road between Denham and the Overlander Roadhouse on the North West Coastal Highway.

Specific reserved areas

= National parks and reserves in the World Heritage Area =

= Bays of the World Heritage area =

= Islands of the World Heritage area =

= Peninsulas of the World Heritage area =

= IBRA sub regions of the Shark Bay Area =

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:{{cite book|year=2007|title=Shark Bay terrestrial reserves and proposed reserve additions: draft management plan 2007|publisher=WA Department of Environment and Conservation; Conservation Commission of Western Australia|location=Bentley, WA|pages=37–39|section=Bioregions; Figure 4: IBRA sub-regions of the Shark Bay Area (map)}}

  • 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

See also

References

{{reflist}}

Further reading

  • {{cite book|author=Duyker, Edward|author-link=Edward Duyker|title=François Péron: An Impetuous Life: Naturalist and Voyager|publisher=Miegunyah/MUP|location=Melbourne, Victoria|date=2006|page=349|isbn=978-0-522-85260-8|postscript=. (Winner, Frank Broeze Maritime History Prize, 2007).}}