Limit to climate change adaption in floodplain wetlands - Macquarie Marshes
Management of water resources for long term ecosystem function
The management of water resources and dependent ecosystems remains one of the most critical issues for Australia, exacerbated by increasing impacts of climate change (rainfall reductions, increased variability, increased temperatures and increased evaporation), affecting many freshwater ecosystems. This is requiring new ways of management with explicit identification of objectives for long-term conservation. Currently, management of freshwater species and ecosystems does not incorporate climate change adaptation to promote their resilience.
The pressures confronting management of water resources are particularly significant for freshwater ecosystems in the Murray-Darling basin, exemplified by the Macquarie Marshes. Drying associated with overexploitation of water resources and climate change, many freshwater plant and animal species and functions in the Macquarie Marshes are close to limits of tolerance and in decline. This is a wetland of international significance (Ramsar-listed), also important for migratory birds (another international responsibility), and one of only three Australian freshwater ecosystems where the international community has been formally informed of the likelihood of a detrimental change in ecological character. Decreasing flows and increasing temperatures, thresholds of change must be resolved urgently to identify management options for conserving freshwater species and ecosystems at or near their climate limits. The Macquarie Marshes are an excellent example of a system sensitive to hydrological processes across multiple scales. There is considerable potential to improve current management that maximises mitigation measures, including the delivery of environmental flows, protection of core refugia and conservation of free-flowing rivers (i.e. Talbragar River) through adaptive management.
For the Macquarie Marshes, climate change will affect conservation goals, policies, and programs, including international obligations, influencing the availability of water, the key ecological driver of the system. Existing planning instruments variously reflect different conservation and water management policies and goals (e.g. Murray-Darling Basin Plan, Water Sharing Plan, Plan of management for Nature Reserve, Catchment action plan, Environmental Water Holder plan, floodplain management plan). Generally, these are poorly integrated for dealing with ecological resilience and flow management through the landscape, despite similar goals to support conservation of wetlands. Further, climate adaptation is currently not incorporated in any plans at local, landscape, catchment or regional scales; the Guide to the Basin Plan only incorporates a 5% decline in flow even though predicted to be at least 15% and more than 40% by 2100, if the last 10 year drought continued.
Climate adaptation plan for the Macquarie Marshes
The key focus of this project aim to development a climate adaptation plan for the Macquarie Marshes, interacting with management of water resources in the agricultural sector, regional urban sectors as well as recreation and tourism sectors, all dependent on water for sustainability. Conservation of the Macquarie Marshes ecosystem could benefit from water management technologies, efficiencies and trading in these other sectors. Through extension of adaptive management, incorporating local knowledge, the proposed adaptation plan will integrate cross-sectoral processes to maximise the benefits for this internationally renowned ecosystem. This project is carried out with financial support of the Australian Government (through the Department of Climate Change and Energy Efficiency and the National Water Commission) and the National Climate Change Adaptation Research Facility (NCCARF) and the NSW Office of Environment and Heritage (OEH).