Boundaries

This ecoregion is flanked in the west by the Great Dividing Range and runs along the eastern coast of Australia from Halifax Bay in the north to Wilsons Promontory in the south.

Topography

Elevations reach upwards of 1300 m asl along the Eastern Highlands, but elevation quickly decreases toward the coast.

Freshwater habitats

This ecoregion is moderately sized, covering 589,000 square kilometers or 7.5% of Australia. Rivers, streams, floodplains, wetlands, and highland lakes are the major freshwater habitats. Many of the rivers in this ecoregion experience seasonal flooding associated with high rainfall events. Streams in northern upland areas from the southern Burdekin River to the Burnett River tend to be intermittent, with upland areas gradually becoming more permanent with perennial flow in higher and wetter headwaters as one moves south. The lower reaches of most rivers have perennial flow, with high seasonal variability. Many of larger rivers have been impounded.

Terrestrial habitats

Eucalypt forests interspersed with patches of rainforest extend through much of the ecoregion, with heath and associated sandplain vegetation near the coast (World Wildlife Fund 2001). Small patches of tropical rainforest are found in the north.

Description of endemic fishes

Neoceratodus forsteri, the Australian lungfish, occurs only in this ecoregion and is the only extant member of the family Neoceratodontidae, which is now endemic to this ecoregion following the extinction of the other six species in the family. One genus, Rhadinocentrus, is endemic. Families with multiple endemic species in this ecoregion are Percichthyidae, Eleotridae, and Melanotaeniidae (rainbowfishes). Australia’s only non-parasitic lamprey, Mordacia praecox, is endemic to this ecoregion.

Justification for delineation

The northern boundary of this ecoregion is marked by a steep decline in species richness and the disappearance of thirteen species between northeastern Queensland and the Burdekin River. The southern boundary is in the vicinity of Wilsons Promontory, which marks the approximate eastern limit of six species. This large province is unusual in that few clear faunal barriers within it exist, yet the fauna at the northern and southern extremes have no species in common. Movement between many basins is likely difficult due to the narrow continental shelf, however, some species do appear to be moving more frequently, suggesting they have some mechanism for movement via the ocean (Unmack 2001). Climate and ecology likely play an important role in determining distributional limits within this province as there is a distinct cline involving the loss and gain of northern and southern species respectively as one compares the fauna of drainages from north to south. However, few of these species share any common distributional boundaries (Unmack 2001).

Level of taxonomic exploration

Overall taxonomic exploration is good. However, many species within this province remain poorly studied and recent evidence suggests several undescribed taxa exist within more widespread forms. These include species in the groups Galaxias, Retropinna, Tandanus, Rhadinocentrus, Pseudomugil signifer (southern blue-eye), Macquaria australasica (Macquarie perch), Nannoperca, Hypseleotris, and Mogurnda (Raadik 2005; Hammer et al. 2007; Jerry & Woodland 1997; Page et al. 2004; Wong et al. 2004; Unmack 2005; Thacker et al. 2007; M. Adams, unpub data).