The Darling River is a 2,739-kilometer long river which arises in the Eastern Highlands region near the New South Wales-Queensland border, and then flows southwest until it merges with the Murray River in Wentworth, New South Wales. It is the third longest river in Australia. Together, the Murray and Darling rivers form the Murray-Darling basin, which drains about one-seventh of the Australian landmass, while the Darling River alone drains an area of 650,000 square kilometers. The Severn River, a perennial river arising in the Great Dividing Range, is considered as the primary source of the Darling. As the Darling River flows past dry areas of salt-bush pastures, it often loses large amounts of water by evaporation. Bourke, Tilpa, Menindee, and Wentworth are some of the most important Australian settlements situated along the course of the Darling River.
Since prehistoric times, the Darling River has served the needs of the human populations settled along its banks. The region drained by the river is thought to have probably been inhabited as far back as 20,000 years ago. Initially, the land was inhabited by the aboriginals of Australia. With the arrival of the Europeans over the past few centuries, the river witnessed the growth of European settlements along its banks, and sheep farming and the sheep wool trade flourished in the region. Since then, the river has become the lifeline for the thousands of Australians who are dependent on the river for agriculture, fishing, animal grazing, and drinking water.
Large sections of arid, pastoral lands along the Darling River Basin are owned by wool growers who utilize the land for their sheep grazing activities. Agricultural lands are found along the more humid sections of the river's basin, wherein farmers own small irrigated areas and primarily grow fodder crops and citrus fruits. Though the river was used as an important transport route for carrying wool grown in western New South Wales to trade centers in South Australia, the irregular flow of the river has currently limited its use as a major water transport route. To some extent, commercial fishing is carried out in the waters of the Darling as well.
Their different dependencies on rainfall divides the vegetation along the Darling basin into two primary types. Namely, these are the western arid region type, supporting steppe vegetation, and the eastern types, which are found in the humid sections of the river that allow agricultural practices to flourish. Fish in the Darling River include a combination of both native and invasive fish species. There are around 35 native species of fish in the Darling, of which about 9 are regarded as nationally "Threatened", and 2 are "Critically Endangered". Besides fish, the Murray-Darling River Basin is also home to several bird, mammalian, amphibian, and reptilian species. Birds like the Mallee emu-wren, the Mallee-fowl, and the Wedge tailed eagle, mammals like the Southern hairy-nosed wombat, and amphibians like the Southern bell frog, are all found residing in and around the river, and many of their habitats are in need of immediate protection.
Threats and Disputes
According to the World Wildlife Fund, the Murray-Darling River ecosystem is one listing among those of the world’s most threatened river systems. Human activities are primarily held responsible for the ongoing degradation of the river system and its surrounding habitats. The introduction of non-endemic fish species, like the European carp and plague minnow, into the river by European settlers has significantly depleted the population of such native species as the silver perch, the Murray cod, and the freshwater catfish in these rivers. The fish species of this ecosystem are also highly susceptible to the stresses induced by climate change and global warming. Excessive water extraction practices by a large, and still growing, human population based along the banks of the river, and the construction of dams and reservoirs, are also leading to a reduced water flow in the river. This is triggering the loss of vast tracts of the floodplain forests and wetlands supported by the river, and a concurrent increase in the soil salinity in the basin areas.