Marine Bioregions of South Australia
Marine bioregions (biogeographic regions) are regions containing distinctly recognisable patterns of biodiversity. For example, the life forms of the cold, exposed waters of the lower south-east differ distinctly from those of the warmer, sheltered waters of upper Spencer Gulf. A number of marine bioregions spanning thousands of square kilometres have been identified around Australia on the basis of biological and physical attributes, through a process called the Interim Marine and Coastal Regionalisation of Australia (IMCRA). A total of 60 bioregions have been defined for Version 3.3 of IMCRA, of which eight overlap at least some part of South Australian waters. Since the publication of IMCRA Version 3.3, further work has been done in South Australia which has resulted in some modifications to the bioregion boundaries. These are reflected in the maps and descriptions shown on this page.
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| Bioregion | Location | Description |
| Eucla | Western Australian border to Cape Adieu (extends westwards to Israelite Bay) | Shallow offshore gradient. Approx. 0.8 to 1.2 m tidal range. Open, moderate energy, west facing coastline. High Nullarbor tertiary limestone cliffs, Pleistocene dune rock headlands and reefs, Holocene beaches and dune barriers. Warm temperate water influenced by periodic intrusion of the Leeuwin current. |
| Murat | Cape Adieu to Point Brown. | Shallow offshore gradient. Moderate to low energy coastline. Microtidal ~ 0.8 to 1.2 m range. Crenulate bays due to Precambrian crystalline rock headlands usually with a dune rock capping. Pleistocene dune rock cliffs, reefs and headlands. Holocene beaches, dunes and estuarine deposits including intertidal and supratidal flats. Offshore islands and seamounts. Warm temperate waters. Leeuwin current |
| Eyre | Point Brown to Cape Torrens, to West Cape, to Port Neill and Cape Willoughby | Shallow to moderate offshore gradients. Moderate to high energy coastline. Pleistocene dune rock cliffs, headlands and shore platforms. Microtidal ~ 0.8 to 1.2 m range. Holocene dune barriers, beaches and lagoon deposits. Precambrian metasediment cliffs. Cainozoic colluvial and fluvial sediments. Cool temperate water subject to nutrient rich upwellings |
| Spencer Gulf | West Cape to Port Neill, Point Riley to Shoalwater Point | Semi-confined. Shallow offshore gradients. Low to moderate energy shorelines. Microtidal ~ 1.8 m range. Precambrian crystalline rock headlands forming embayments. Cainozoic outwash sediments forming low cliffs. Holocene beaches, dunes and estuarine deposits. Warm temperate waters |
| Northern Spencer Gulf | Point Riley to Port Augusta to Shoalwater Point | Confined, inverse estuary with minimal land water input. Shallow offshore gradients. Low energy shorelines. Micro to mesotidal ~ 1.8 to 3.6 m range. Precambrian metasediment shore platforms. Holocene sandflats, beach ridges, recurved spits, and extensive intertidal and supratidal flats. Warm temperate waters with a subtropical biotic element |
| Gulf St Vincent | Cape Torrens to West Cape, Port Elliot to Cape Willoughby | Confined inverse estuary. Shallow offshore gradients. Low to moderate energy coastline. Micro to mesotidal ~ 1.2 to 3.3 m range. Precambrian metasediment and Tertiary cliffs. Holocene beaches, sandflats, dunes, beach ridges, estuarine deposits, extensive intertidal and supratidal flats. Warm temperate waters. High tidal flow environments at the southern corners of the Gulf |
| Coorong | Port Elliot to Cape Jaffa | Offshore gradient decreases from steep to flat resulting in a gradational coastline change from high to low energy. Microtidal ~ 0.8 to 1.2 m range. Precambrian crystalline rock and metasediment headlands and cliffs. Pleistocene dune rock cliffs, headlands, shore platforms and reefs. Holocene pocket beaches and an extensive beach-dune barrier lagoon complex. Cool temperate waters |
| Otway | Cape Jaffa to Victorian border (extends eastwards to slightly north of Apollo Bay and including King Island environs) | Very steep to moderate offshore gradients. High wave energy. Currents generally slow, but moderately strong through entrance to Bass Strait. Cold temperate waters subject to nutrient rich upwellings |
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| This page was last modified 2006-09-04 | ||
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