Freshwater ecosystems are considered to be among the ecosystems most vulnerable to global climate change.1
Observational records and climate projections provide abundant evidence that freshwater resources have the
potential to be strongly impacted by climate change, with wide-ranging consequences for human societies and ecosystems.1 Observed global trends in precipitation, humidity, drought and run-off indicate that southern Africa is on a negative trajectory with respect to changes associated with climate change.2 South Africa is a water-stressed country with a mean annual precipitation (MAP) of 500 mm per annum (approximately 60% of the world average3), with 65% of the country, especially the arid and semi-arid interior and western regions, receiving on average 10 in the arid west.5 Given the most probable scenario of a growing economy and population, climate change has major implications for aquatic ecosystems and for their ability to deliver ecosystem services.