The Southwest Shelf Province, also known as the Leeuwin

marine ecoregion A marine ecoregion is an ecoregion, or ecological region, of the oceans and seas identified and defined based on biogeography, biogeographic characteristics. Introduction A more complete definition describes them as “Areas of relatively homogen ...

, is a

biogeographic Biogeography is the study of the distribution of species and ecosystems in geographic space and through geological time. Organisms and biological communities often vary in a regular fashion along geographic gradients of latitude, elevation, ...

region of

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

continental shelf A continental shelf is a portion of a continent that is submerged under an area of relatively shallow water, known as a shelf sea. Much of these shelves were exposed by drops in sea level during glacial periods. The shelf surrounding an island ...

. It includes the temperate coastal waters of

Southwest Australia Southwest Australia is a biogeographic region in Western Australia. It includes the Mediterranean-climate area of southwestern Australia, which is home to a diverse and distinctive flora and fauna. The region is also known as the Southwest Aus ...

Geography

The Southwest Shelf Province includes the coastal waters and continental shelf of

south west The points of the compass are a set of horizontal, radially arrayed compass directions (or azimuths) used in navigation and cartography. A compass rose is primarily composed of four cardinal directions—north, east, south, and west—each sepa ...

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 th ...

, extending from the vicinity of

Perth Perth is the capital and largest city of the Australian state of Western Australia. It is the fourth most populous city in Australia and Oceania, with a population of 2.1 million (80% of the state) living in Greater Perth in 2020. Perth is ...

on the west coast to

Israelite Bay Israelite Bay is a bay and locality on the south coast of Western Australia. Situated in the Shire of Esperance local government area, it lies east of Esperance and the Cape Arid National Park, within the Nuytsland Nature Reserve and the Grea ...

on the

south coast South Coast is a name often given to coastal areas to the south of a geographical region or major metropolitan area. Geographical Australia *South Coast (New South Wales), the coast of New South Wales, Australia, south of Sydney * South Coast (Q ...

. The continental shelf is generally narrow, with some small offshore islets, including the

Recherche Archipelago The Archipelago of the Recherche, known locally as the Bay of Isles, is a group of 105 islands, and over 1200 "obstacles to shipping", off the south coast of Western Australia. The islands stretch from east to west and to off-shore encomp ...

. The coastline is affected by heavy, high-energy swells. Rocky headlands of granitic, doleritic, or gneissic rock are found along much of the coast, interspersed with curving bays and sandy beaches. Seagrass meadows are found in sheltered bays and inlets. The warm

Leeuwin Current The Leeuwin Current is a warm ocean current which flows southwards near the western coast of Australia. It rounds Cape Leeuwin to enter the waters south of Australia where its influence extends as far as Tasmania. Discovery The existence of the ...

runs southwards along the west coast, and turns eastwards to follow the south coast. A colder inshore counter-current runs northwards along the west coast. The

Southwest Shelf Transition The Southwest Shelf Transition, also known as the Houtman marine ecoregion, is a biogeographic region of Australia's continental shelf and coastal waters. It includes the subtropical coastal waters of Southwest Australia. Geography The Southwes ...

, or Houtman marine bioregion, lies to the north. The

Great Australian Bight The Great Australian Bight is a large oceanic bight, or open bay, off the central and western portions of the southern coastline of mainland Australia. Extent Two definitions of the extent are in use – one used by the International Hydrog ...

lies to the east."A Guide to the Integrated Marine and Coastal Regionalisation of Australia Version 4.0". Department of Environment and Heritage, Government of Australia. June 2006. ISBN 0 642 552274.

Meso-scale bioregions

The

Integrated Marine and Coastal Regionalisation of Australia The Integrated Marine and Coastal Regionalisation of Australia (IMCRA), formerly the Interim Marine and Coastal Regionalisation for Australia, is a biogeographic regionalisation of the oceanic waters of Australia's exclusive economic zone (EE ...

(IMCRA) identifies two meso-scale bioregions that make up the province. * Leeuwin–Naturaliste (LNE) extends from Perth on the west coast to Black Head (near

Wellstead Wellstead is a small rural town situated in Western Australia in the Great Southern region between Albany and Esperance. The name commemorates the Wellstead family who settled in the area in 1860 and had held grazing land between Cape Riche ...

) on the south coast. * Western Australia South Coast (WSC) extends along the south coast from Black Head to

References

{{reflist Biogeography of Western Australia Ecoregions of Australia Marine ecoregions Southwest Australia Temperate Australasia IMCRA provincial bioregions