Physical and ecological associations in dryland refugia: waterholes of the Cooper Creek, Australia

Waterholes are a significant morphological feature of the Cooper
Creek system in central Australia. Many of these waterholes contain water
over extended no flow periods and are recognized as important réfugia for
aquatic biota. This paper explores how morphological features may influence
ecosystem processes within waterholes. Each waterhole was characterized via
a suite of morphological variables and it was found that the maximum fetch
length was an important variable that separated waterholes into two groups.
Water turbidity of these two groups of waterholes was different, as were rates
of benthic production and respiration. Benthic production and therefore energy
available to support the food webs of these waterholes was greater in the
group of waterholes with shorter fetch lengths and lower turbidity. The
possible associations between morphology, turbidity, and primary production
highlight the importance of understanding the physical template of these
dryland river ecosystems.