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Natural Heritage Values of the Lake Eyre Basin in South Australia: World Heritage Assessment - 1995

CSIRO Division of Wildlife and Ecology, Canberra, 1995

Executive Summary

An assessment of the natural heritage values of the Lake Eyre Basin in South Australia was carried out by surveying scientific literature concerned with geomorphology, hydrology, palaeontology, limnology, biology, ecology and environmental management. The survey aimed to identify features of the Lake Eyre Basin in South Australia that appear to be unique or unusual compared to other parts of Australia and then to assess these against World Heritage Criteria.

The survey results suggested that of the terrestrial and aquatic systems studied, the mound springs and the surface aquatic systems of the Lake Eyre Basin in South Australia have significant natural heritage values. These values were assessed against World Heritage Criteria to decide if they were of outstanding universal value.

The mound springs of the Lake Eyre Basin in South Australia are unusual and highly distinctive because their pools form islands of water for aquatic organisms in an arid environment. Their persistence over tens of thousands of years has allowed certain groups of aquatic animals to develop suites of distinct species to a dramatic degree, such that species are sometimes isolated in one or a few springs. However, the South Australian springs, although unusual, are not unique and have parallels not only in Queensland but also in the United States and Mexico. It does appear, though, that the Australian springs, and particularly those in South Australia, may be among the most numerous and extensive in the world.

In our opinion, the mound springs of the South Australian section of the Lake Eyre possess significant natural heritage values. However, we believe that it is impossible to assess the values of these mound springs against World Heritage Criteria without a simultaneous assessment of those Queensland springs that also lie in the Basin.

The surface aquatic systems of the Lake Eyre Basin in South Australia are unique in Australia. These surface aquatic drainage systems occur in the driest environment in Australia, they constitute the largest internally-draining system in Australia (and one of the world's

largest), they are entirely fed from an arid and semi-arid catchment, they terminate in the vast saline Lake Eyre, the biggest such lake in Australia and among the largest in the world, they are highly variable

in flow pattern and therefore create a wide array of ecological conditions, they support a rich and abundant aquatic fauna, particularly large aggregations of waterbirds, and they remain entirely unregulated. We conclude that Lake Eyre's size, its endorheic drainage system, and the variability of its flooding, result in it being highly distinctive on the global scale. As with Lake Eyre, the Coongie Lakes appear highly distinctive, if not unique, at the global level. Global comparisons of the Cooper and Warburton with other large rivers suggest that the former are indeed highly distinctive, if not unique, in their entirely arid catchment, in their endorheism, in their exceptionally variable hydrology, and in their termination in a large saline playa.

Our assessment suggests that the significant natural heritage values of certain surface aquatic systems of the South Australian section of the Lake Eyre Basin are of World Heritage value. These systems are the Cooper and Warburton Creek drainages, Coongie Lakes, Goyder Lagoon, and Lake Eyre North and South.

In our opinion, these surface aquatic systems meet three of the Criteria for World Heritage properties, namely (i) outstanding examples of physiographic features, (ii) outstanding examples of significant on- going ecological and biological processes, and (iii) superlative

natural phenomena and areas of exceptional natural beauty and aesthetic importance. The systems may also meet Criterion (iv), significant natural habitats for in-situ conservation of biological diversity including threatened species, but with less certainty than that with which they appear to meet the first three Criteria.

Several of the Conditions of Integrity appear to be met by the surface aquatic systems, but in other cases they may not. Where there is doubt about the Conditions, it reflects the fact that the South Australian systems are dependent upon the flow of water from areas of the Lake Eyre Basin in Queensland and, therefore, from outside the area under consideration.