The ecology of episodic saline lakes of inland Eastern Australia, as exemplified by a ten year study of the Rockwell-Wombah lakes of the Paroo

Studies on salt lakes are mostly snapshots of their unique characteristics and relationships. Longer term studies provide different perspectives on variability in hydrology, salinity and biological communities.Such a study on five lakes near the Paroo River in the north western Murray-Darling Basin showed most hold water episodically for about 80% of the time, but each fluctuate over a characteristic salinity range: unnamed lake 0.6 - 19 gL⁻¹, Wombah 1.2 - 30 gL⁻¹, North Blue 0.3 - 31 gL⁻¹, Mid Blue 0.7 - 103 gL⁻¹,and Bulla 1.8 - 262 gL⁻¹. Generally, instantaneous biodiversity is low and not necessarily correlated with salinity, but unlike southern seasonal salt lakes, species accumulation lists are long, approaching 80 species of invertebrates, 50 bird species and a few fish species per lake. Diversity is promoted by salinity fluctuation and habitat heterogeneity. Most species reach peak abundance in any season as long as conditions are with in their physiological salinity tolerances. Invertebrate fauna is of inland affinities, but with some localized substractions and additions explained by hydrology and/or salinity; water bird numbers are influenced by events elsewhere in Australia as well as by local conditions. Like most naturally salinised lakes, production can be high, especially at low to moderate salinities and algal blooms occur naturally from time to time.