Murchison

The Murchison subegion of the Western Australian Rangelands covers an area of approximately 331,775 square kilometres. It is bordered by the South West Region and Goldfields subregion in the south, the Gascoyne subregion in the North, the Indian Ocean to the west and the Desert Rangelands to the east.

According to the Australian Bureau of Statistics, around 7083 people lived in the Murchison subregion in 2011.

History and Economy

For thousands of years the Murchison has been home to many different Indigenous groups. These groups are collectively known as the Yamaji People. Much of the traditional customs and knowledge of the Yamaji People has been lost as a result of dispossession of their homelands. The culture of the Yamaji People has been slowly eroded by the dominance of the western culture, however, the spirit and identity of these people still remains very strong.

In the early 1800s European exploration and settlement of the subregion began. On his voyage to the Shark Bay region and subsequent journey to Perth, Lieutenant George Gray named and explored many of the coastal geographical features. By the 1850s pastoralism, agriculture and mining industries had begun to establish. In the late 1880s gold prospectors sought fortune in the Murchison gold rushes.

Today the major towns of the Murchison are Leinster, Leonora, Meekatharra, Mount Magnet, Laverton, Cue and Wiluna. The main economic activities of the region include mining, agriculture, fishing and tourism.

Resources that are being mined in the region include gold, coal, iron, mineral sands, copper, lead, zinc, magnesite, nickel, talc, uranium, vanadium and titanium.

Agricultural industries include cereal and legume crops e.g. wheat, lupins and canola, livestock e.g. cattle, sheep, pigs and goats, horticulture and aqaculture.

The Murchison subregion is a popular tourist destination. Visitors to this region make an important contribution to the regions local economy.

This subregion also has a strong manufacturing sector. Most of the manufacturing businesses are focussed on servicing the agriculture, mining and fishing industries.

Natural Environment

Climate

The climate of the Murchison is semi-arid to arid, with hot summers and mild winters. Temperatures are highest between January and February, during this time inland average temperatures generally exceed 37°C. Due to sea breezes, coastal temperatures are kept well below those inland. Average winter temperatures are below 18°C. The average annual rainfall of the Murchison is between 190 mm to 250 mm Rainfall in the Murchison is unreliable. Most of the rainfall occurs in winter and most years there is a dry period of four to sixmonths.

Rivers

The watercourses of the Murchison are ephemeral, meaning the rivers dry up for at least part of the year. The major catchment of the region is the Murchison River catchment.The Murchison River Basin has a total area of approximately 91,000 km2 and discharges into the Indian Ocean at Kalbarri. It includes tributaries of the Sandford, Roderick, Yalgar and Hope rivers.

Wetlands

Although much of the subregion’s surface water is ephemeral, there are a number of permanent pools and soaks that survive the summer as wetlands. Wetlands of national significance in the Murchison subregion are Hamelin Pool, Murchison River (lower reaches), Anneen Lake (Lake Nannine), Breberle Lake, Lake Ballard, Lake Barlee, Lake Marmion and Wooleen Lake.

Coastline

The major area of coastline in the Murchison subregion is the Shark Bay World Heritage Area. The Shark Bay World Heritage Area is Australia’s largest enclosed marine embayment. It covers an area more than 2.2 million hectares and has a coastline greater than 1,500 km long.

Flora and Fauna

The biodiversity of the Murchison is rich and varied across extensive terrestrial ecosystems. The Shark Bay World Heritage Area is an exceptional marine and coastal zone. This subregion contains 18 species of Declared Rare Flora (DRF), 95 Priority One Flora, 49 Priority Two Flora, 142 Priority Three Flora and 26 Priority Four Flora. There are no threatened ecological communities known to occur here.

Vegetation

Vegetation is predominantly chenopod and Acacia shrublands and woodlands, however many other vegetation types can be found within this region. The Murchison subregion is essentially Western Australia’s mulga region. Vegetation within this subregion is closely associated with the climate, geology and soils. Mulga low woodlands are supported by areas of outcropping rock with skeletal soils. On calcareous soils there are hummock grasslands and saltbush shrublands while on saline alluvium areas there are samphire (Halosarcia sp.) low shrubland. To the east of the subregion, mallee-mulga parkland over hummock grassland is supported by red sand plains. The lake margins in the Murchison are dominated by lignum (Muehlenbaeckia cunninghamii) and low open woodland of river red gum (Eucalyptus camuldulensis).

IBRA Subregions

The Murchison contains two IBRA sub-regions: Murchison and Yalgoo. To read more about IBRA subregions, and to access the Australian Government’s detailed descriptions of each, visit the Department of the Environment and Energy.