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Keywords:

  • Neales River;
  • Lake Eyre Basin;
  • salinity;
  • refugia;
  • springs;
  • evaporation modelling

ABSTRACT

The conservation priorities for protecting aquatic habitat of arid zone rivers requires an understanding of the drivers of distribution, characteristics and persistence of aquatic refugia in ephemeral to intermittent arid zone rivers. We describe and analyse the aquatic refugia that persist during drought periods in a large, arid, ephemeral river, the Neales River of central Australia, concentrating on refugia for fish and the hydrological processes that influence their location, characteristics and persistence. Field data were collected on flow events, water-level fluctuations in waterbodies during periods of no flow, waterbody dimensions and salinity. Modelling of open-water evaporation rates, analysis of salinity changes and frequency of flow events were used to investigate the main processes determining the persistence of waterbodies. The catchment contained both fluvial waterholes and artesian springs providing aquatic refugia. In addition, anthropogenic refugia, in the form of small dams situated on the floodplain and uncontrolled flow from artesian bores, also provided potential refuge. The catchment only contained one waterhole that had a cease-to-flow depth sufficient to persist over a no-flow period of 24 months, but this would also dry within 24–30 months. The capacity of the artesian springs to act as refugia is limited by their shallow depths and limited connectivity with the main river system. These data illustrate the vulnerability of the fluvial ecology of ephemeral, arid zone rivers to long-term droughts and water resource use and assist in identifying specific refugia that require conservation management. Copyright © 2014 John Wiley & Sons, Ltd.