The Southwest Shelf Transition, also known as the Houtman marine ecoregion, [1] is a biogeographic region of Australia's continental shelf and coastal waters. It includes the subtropical coastal waters of Southwest Australia.
The Southwest Shelf Transition, also known as the Houtman marine ecoregion, [1] is a biogeographic region of Australia's continental shelf and coastal waters. It includes the subtropical coastal waters of Southwest Australia.
The Southwest Shelf Transition includes the coastal waters and continental shelf of the west coast of Western Australia, extending from Kalbarri to Perth, and including the Houtman Abrolhos archipelago. It is a transitional zone between the subtropical Central Western Shelf Province to the north, and the warm temperate Southwest Shelf Province to the south. The warm Leeuwin Current runs southwards along the coast. [2]
The continental shelf is generally narrow. The coastline is affected by moderate-energy swells from the Indian Ocean. [3]
Depth ranges from zero to nearly 300 metres, with a mean depth of 41 metres. Geomorphically the seabed is almost entirely shelf, but there is a small area of scarp at the northern limits. [4]
The Houtman Abrolhos Archipelago lies about 60 km from the mainland coast, near the edge of the continental shelf. The archipelago is made up of three groups of low islands. Each group rests on a shallow undersea carbonate platform that includes extensive coral reefs. It is the southernmost coral reef system in the Indian Ocean.
Biologically, it is a highly complex transition zone, with many species from other provinces reaching a limit of their range in this bioregion. In particular, it represents a northern limit of a number of warm temperate species, and the southern limit of a number of sub-tropical and tropical species. The Houtman Abrolhos is home to the highest concentration of west coast endemic species. [5]
The Integrated Marine and Coastal Regionalisation of Australia (IMCRA) identifies two meso-scale bioregions that make up the transition. [3]
This bioregion was referred to as the South Western Biotone in Integrated Marine and Coastal Regionalisation of Australia (IMCRA) Version 3.3, [3] and as the Southwest IMCRA Transition in the National Marine Bioregionalisation of Australia. Both Southwest IMCRA Transition and Southwest Shelf Transition are used in IMCRA Version 4.0. [2]
The Houtman Abrolhos is a chain of 122 islands, and associated coral reefs, in the Indian Ocean off the west coast of Australia, about eighty kilometres (50 mi) west of Geraldton, Western Australia. It is the southernmost true coral reef in the Indian Ocean, and one of the highest latitude reef systems in the world. It is one of the world's most important seabird breeding sites, and is the centre of Western Australia's largest single-species fishery, the western rock lobster fishery. It has a small seasonal population of fishermen, and a limited number of tourists are permitted for day trips, but most of the land area is off limits as conservation habitat. It is well known as the site of numerous shipwrecks, the most famous being the Dutch ships Batavia, which was wrecked in 1629, and Zeewijk, wrecked in 1727.
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 (EEZ). As of 2008, the most recent version is IMCRA Version 4.0.
The Bass Strait Shelf Province is a biogeographic region of Australia's coastal and continental shelf waters. It covers the central Bass Strait between Tasmania and the southern Australian mainland. It is a provincial level bioregion in the Integrated Marine and Coastal Regionalisation of Australia (IMCRA) system. The Bassian and adjacent Tasmanian Shelf provinces correspond to the Bassian marine ecoregion in the WWF's Marine Ecoregions of the World system.
The Central Eastern Shelf Province is a biogeographic region of Australia's coastal and continental shelf waters. It includes the warm temperate coastal waters of eastern Australia. It is a provincial level bioregion in the Integrated Marine and Coastal Regionalisation of Australia (IMCRA) system. It corresponds to the Manning-Hawkesbury marine ecoregion in the WWF's Marine Ecoregions of the World system.
Tweed–Moreton, also known as the Central Eastern Shelf Transition, is a marine biogeographic region of eastern Australia.
The Central Western Shelf Province, also known as the Shark Bay marine ecoregion, is a biogeographic region of Australia's continental shelf and coastal waters. It includes the subtropical coastal waters of Western Australia.
The Northeast Shelf Province is a biogeographic region of Australia's coastal and continental shelf waters. It includes the tropical coastal waters of the central and southern Great Barrier Reef in northeastern Australia. It is a provincial level bioregion in the Integrated Marine and Coastal Regionalisation of Australia (IMCRA) system. It corresponds to the Central and Southern Great Barrier Reef marine ecoregion in the WWF's Marine Ecoregions of the World system.
The Northeast Shelf Transition is a biogeographic region of Australia's coastal and continental shelf waters. It includes the tropical coastal waters of the northern Great Barrier Reef and the Torres Strait in northeastern-most Australia. It is a provincial level bioregion in the Integrated Marine and Coastal Regionalisation of Australia (IMCRA) system. It corresponds to the Torres Strait and Northern Great Barrier Reef marine ecoregion in the WWF's Marine Ecoregions of the World system.
The Northern Shelf Province, also known as Arnhem Coast to Gulf of Carpentaria, is a biogeographic region of Australia's continental shelf. It includes the coastal waters of Arnhem Land and the Gulf of Carpentaria in Northern Australia.
The Northwest Shelf Province, also known as Exmouth to Broome, is a biogeographic region of Australia's continental shelf.
The Northwest Shelf Transition, also known as Bonaparte Coast, is a biogeographic region of Australia's continental shelf. It adjoins the Kimberley region of Western Australia and the adjacent coast of the Northern Territory.
The Southeast Shelf Transition is a biogeographic region of Australia's coastal and continental shelf waters. It covers a portion of Australia's southeastern coast, from southern New South Wales to eastern Victoria, including the islands of the Kent Group and Furneaux Group at the eastern end of the Bass Strait. It is a provincial level bioregion in the Integrated Marine and Coastal Regionalisation of Australia (IMCRA) system, and is a transitional region between the warm temperate Central Eastern Shelf Province to the northwest and the cool temperate Bass Strait Shelf and Tasmanian Shelf provinces to the west and south. It corresponds to the Cape Howe marine ecoregion in the WWF's Marine Ecoregions of the World system.
The Southwest Shelf Province, also known as the Leeuwin marine ecoregion, is a biogeographic region of Australia's continental shelf. It includes the temperate coastal waters of Southwest Australia.
The Spencer Gulf Shelf Province, also known as the South Australian Gulfs marine ecoregion, is a biogeographic region of Australia's continental shelf and coastal waters. It includes the warm temperate coastal waters of South Australia's central coast. It is a provincial bioregion in the Integrated Marine and Coastal Regionalisation of Australia (IMCRA) system.
The Tasmanian Shelf Province is a biogeographic region of Tasmania's coastal and continental shelf waters. It covers the western, eastern, and southern coasts of Tasmania. It is a provincial level bioregion in the Integrated Marine and Coastal Regionalisation of Australia (IMCRA) system. The Tasmanian Shelf and adjacent Bass Strait Shelf provinces correspond to the Bassian marine ecoregion in the WWF's Marine Ecoregions of the World system.
The Western Bass Strait Shelf Transition is a biogeographic region of Australia's coastal and continental shelf waters. It is a transitional region between the cold-temperate Bass Strait Shelf and Tasmanian Shelf provinces and the warm-temperate Spencer Gulf Shelf Province. It is a provincial bioregion in the Integrated Marine and Coastal Regionalisation of Australia (IMCRA) system. It is the southern portion of the Western Bassian marine ecoregion in the World Wildlife Fund's (WWF) Marine Ecoregions of the World system.
Western Australia has the longest coastline of any state or territory in Australia, at 10,194 km or 12,889 km. It is a significant portion of the coastline of Australia, which is 35,877 km.
The South-west Corner Marine Park is a marine protected area on the lower south west and southern coast of Western Australia, one of 14 in the South-west Marine Parks Network.
The marine ecoregions of the South African exclusive economic zone are a set of geographically delineated regions of similar ecological characteristics on a fairly broad scale, covering the exclusive economic zone along the South African coast.
The Bassian ecoregon is a biogeographic region of Australia's coastal and continental shelf waters. It includes the cold-temperate waters surrounding Tasmania, including the central Bass Strait between Tasmania and the southern Australian mainland. This ecoregion, designated in the Marine Ecoregions of the World system by the World Wildlife Fund (WWF), includes both the Bass Strait Shelf and Tasmanian Shelf provincial level bioregions from the Integrated Marine and Coastal Regionalisation of Australia (IMCRA) system.