The southern mud oyster, Australian flat oyster, native flat oyster, native mud oyster, or angasi oyster (''Ostrea angasi''), is endemic to southern

Australia Australia, officially the Commonwealth of Australia, is a sovereign country comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands. With an area of , Australia is the largest country by ...

, ranging from

Western Australia Western Australia (commonly abbreviated as WA) is a state of Australia occupying the western percent of the land area of Australia excluding external territories. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to t ...

to southeast

New South Wales ) , nickname = , image_map = New South Wales in Australia.svg , map_caption = Location of New South Wales in AustraliaCoordinates: , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , es ...

and around

Tasmania ) , nickname = , image_map = Tasmania in Australia.svg , map_caption = Location of Tasmania in AustraliaCoordinates: , subdivision_type = Country , subdi ...

. ''Ostrea angasi'' superficially resembles ''

Ostrea edulis ''Ostrea edulis'', commonly known as the European flat oyster, is a species of oyster native to Europe. In Britain and Ireland, regional names include Colchester native oyster, mud oyster, or edible oyster. In France, ''Ostrea edulis'' are known ...

'' and both species may be referred to with the name "flat oyster". However, the two species do not occur naturally in the same geographic distribution.

Habitat

This species is found in sheltered, silty or sand-bottomed

estuaries An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environme ...

at depths between 1 and 30 metres.

Diet

Flat oysters, like all other

oyster Oyster is the common name for a number of different families of salt-water bivalve molluscs that live in marine or brackish habitats. In some species, the valves are highly calcified, and many are somewhat irregular in shape. Many, but not ...

species, are

filter feeder Filter feeders are a sub-group of suspension feeding animals that feed by straining suspended matter and food particles from water, typically by passing the water over a specialized filtering structure. Some animals that use this method of feedin ...

s, feeding on, and taking in anything small enough to be filtered in their

gills A gill () is a respiratory organ that many aquatic organisms use to extract dissolved oxygen from water and to excrete carbon dioxide. The gills of some species, such as hermit crabs, have adapted to allow respiration on land provided they are ...

. This may include

plankton Plankton are the diverse collection of organisms found in water (or air) that are unable to propel themselves against a current (or wind). The individual organisms constituting plankton are called plankters. In the ocean, they provide a cruc ...

microalgae Microalgae or microphytes are microscopic algae invisible to the naked eye. They are phytoplankton typically found in freshwater and marine systems, living in both the water column and sediment. They are unicellular species which exist indiv ...

inorganic In chemistry, an inorganic compound is typically a chemical compound that lacks carbon–hydrogen bonds, that is, a compound that is not an organic compound. The study of inorganic compounds is a subfield of chemistry known as ''inorganic chemist ...

material.

Predators

Oyster growers at

Coffin Bay, South Australia Coffin Bay, originally Coffin's Bay, is a town at the southern extremity of the Eyre Peninsula, a wheat growing area of South Australia. At the 2016 census, Coffin Bay had a population of 611. Material was copied from this source, which is avai ...

have observed stingrays eating their experimental commercial stocks of ''Ostrea angasi''.

Commercial harvesting

Extensive oyster reefs in southern Australia were largely destroyed by over-exploitation during the 19th and early 20th Centuries. Oysters were dredged directly from the seabed. In the 21st century, commercial oyster growers in southern

have started experimentally

farming Agriculture or farming is the practice of cultivating plants and livestock. Agriculture was the key development in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that enabled peopl ...

''O. angasi'' as a means to diversify their businesses. This was prompted by other growers suffering massive stock losses of ''

Crassostrea gigas The Pacific oyster, Japanese oyster, or Miyagi oyster (''Magallana gigas''), is an oyster native to the Pacific coast of Asia. It has become an introduced species in North America, Australia, Europe, and New Zealand. Etymology The genus ''Ma ...

'' resulting from outbreaks of Pacific Oyster Mortality Syndrome (POMS)''.''

Not-for-profit projects

The not-for-profit organisation Estuary Care Foundation was established in

South Australia South Australia (commonly abbreviated as SA) is a States and territories of Australia, state in the southern central part of Australia. It covers some of the most arid parts of the country. With a total land area of , it is the fourth-largest o ...

to undertake trials growing ''Ostrea angasi'' in the

Port River The Port River (officially known as the Port Adelaide River) is part of a tidal estuary located north of the Adelaide city centre in the Australian state of South Australia. It has been used as a shipping channel since the beginning of European ...

and adjacent waters. The organisation is also involved in

seagrass Seagrasses are the only flowering plants which grow in marine environments. There are about 60 species of fully marine seagrasses which belong to four families ( Posidoniaceae, Zosteraceae, Hydrocharitaceae and Cymodoceaceae), all in the ...

monitoring and restoration work within the Port River.

Windara Reef

Windara Reef Ardrossan is a town in the Australian state of South Australia located on the eastern coast of the Yorke Peninsula, about by road from the Adelaide city centre. It is notable for its deepwater shipping port and its towering coastal cliffs of re ...

was constructed in Gulf St Vincent, offshore from

Ardrossan Ardrossan (; ) is a town on the North Ayrshire coast in southwestern Scotland. The town has a population of 10,670 and forms part of a conurbation with Saltcoats and Stevenston known as the ' Three Towns'. Ardrossan is located on the east shore ...

, to promote the reestablishment of ''Ostrea angasi''. The reef was also opened to recreational fishers in 2017. As of April 2019, it was the largest shellfish reef restoration project in the southern hemisphere.

The Nature Conservancy The Nature Conservancy (TNC) is a global environmental organization headquartered in Arlington, Virginia. it works via affiliates or branches in 79 countries and territories, as well as across every state in the US. Founded in 1951, The Nat ...

, the

Australian Government The Australian Government, also known as the Commonwealth Government, is the national government of Australia, a federal parliamentary constitutional monarchy. Like other Westminster-style systems of government, the Australian Governmen ...

, the

South Australian Government The Government of South Australia, also referred to as the South Australian Government, SA Government or more formally, His Majesty’s Government, is the Australian state democratic administrative authority of South Australia. It is modelled o ...

, the

Yorke Peninsula Council The Yorke Peninsula Council is a local government area in South Australia. Its boundaries include most of the Yorke Peninsula. The council seat is at Maitland; the council also maintains branch offices at Minlaton and Yorketown. History It c ...

, The

University of Adelaide The University of Adelaide (informally Adelaide University) is a public research university located in Adelaide, South Australia. Established in 1874, it is the third-oldest university in Australia. The university's main campus is located on N ...

and the

Ian Potter Foundation Sir William Ian Potter (25 August 190224 October 1994), known as Ian Potter, was an Australian stockbroker, businessman and philanthropist. Potter was knighted in 1962. The Ian Potter Foundation, which he established in 1964, has made grants to ...

have each contributed to funding the project.

Habitat

Diet

Predators

Commercial harvesting

Not-for-profit projects

Windara Reef

References

Further reading