Novel methods for managing freshwater refuges against climate change in southern Australia
Authors: Belinda J. Robson, Edwin T. Chester, Mark Allen, Stephen Beatty, Jane M. Chambers, Paul Close, Barbara Cook, Courtney R. Cummings, Peter M. Davies, Rebecca E. Lester, Alan Lymbery, Ty G. Matthews, David Morgan and Melanie Stock
As climate change progresses, how can freshwater refugia be maintained within tolerable ranges for resident species? How can connectivity between refugia be enhanced? Four approaches to this issue controlled Cool Water Release (CWR), strategic streamside revegetation, adaptation of artificial urban wetlands, and modification of river connectivity were assessed through a literature review and various experiments for their potential application in South Australia. The creation of freshwater refuges by riparian replanting or modifying artificial wetlands can be done now, but will take decades to reach maximum effectiveness. Knowledge gaps will also limit the utility of these approaches, so investment, trials and further research are required. The removal of barriers to improve river connectivity is feasible in South Australia, as has been demonstrated to be both ecological and cost-effective overseas. The method could be made more effective through improving barrier identification surveys and properly monitoring barrier decommissioning. CWR has not yet been used in Australia to deliberately lower stream temperatures, and is not feasible or cost-effective and this current time, due to there being too many knowledge gaps and uncertainties. Future feasibility will depend on filling of knowledge gaps, and development of new technology and techniques. All four approaches would provide multiple benefits to both the environment and human society through protecting biodiversity and ecosystem services.