Ecoregions

Central Australian Freshwater - A Global Ecoregion

Located in the most arid part of Australia

Lake Eyre dragon (Ctenophorus maculosus), endemic to the salt lake of Lake Eyre, Australia.

Snapshot: Ecoregion 193

Size:
1,340,000 sq. km (517,000 sq. miles)

Habitat type:
Xeric Basins

Geographic Location:
Central Australia

Conservation Status:
Vulnerable

Quiz Time

Is true that the Lake Eyre is dry most of the times?

Answer:
The heat in central Australia quickly evaporates much of the rain that falls, so lakes like Eyre are intermittent. When full, they are generally encircled by deposits of salt. In fact, it fills completely only about twice every century and takes two years to dry up again.

About the Area
Characterised by some of the most unpredictable flow patterns of any continent, freshwater systems in arid Australia support species with amazing adaptations to environmental variability. This ecoregion has high levels of local endemism with many species that have survived here for millions of years.

This ecoregion is defined primarily by the interior-draining Lake Eyre and Bulloo-Bancannia drainage basins, though it also overlays a portion of the Great Artesian Basin, one of the world's largest artesian (underground) basins.

Around the artesian basin occur numerous mound springs and spring-fed complexes, such as Dalhousie Springs. These springs, some of which are as warm as 46°C, can be as old as a million years.

Local Species
Seen here are exceptional levels of endemism in fish, wetland-dependent plants, amphipods, ostracods, isopods, and snails (more than 20 species in at least 2 endemic genera). A large portion of this ecoregion's freshwater species exhibits highly restricted ranges, though a few such as Spanged perch (Leiopotherapon unicolor) are more widespread.

The Dalhousie Springs fauna is notable for its extremely high endemicity that includes species like the Dalhousie catfish (Neosilurus sp.), Dalhousie hardyhead (Craterocephalus dalhousiensis), Dalhousie mogurnda (Mogurnda sp.), and Dalhousie goby (Chlamydogobius gloveri).

Other endemics found at Dalhousie Springs are at least 6 snails, 1 blind crustacean, possibly 1 crayfish, and 1 frog species. Endemic plants to the mound springs in general include Halosarcia fontinalis and Eriocaulon carsonii.

Threats
In this arid ecoregion, any water withdrawals or other modifications to the flow regime pose serious threats to aquatic species. Illegal fishing, exotic species, overgrazing, and untreated sewage disposal threaten the fragile aquatic ecosystems. In addition, proposed dams, water diversions, and commercial fisheries pose a future threat.

Resources
• NationalGeographic.com