Yung En Chee (Waterway Ecosystem Research Group, University of Melbourne), Rhys Coleman (Melbourne Water), Sharyn Ross Rakesh (Melbourne Water), Nick Bond (Centre for Freshwater Ecosystems, La Trobe University) and Chris Walsh (Waterway Ecosystem Research Group, University of Melbourne).
Ecological modelling and waterway management prioritisation in greater Melbourne
Images (L-R): A/Prof Chris Walsh, Dr Rhys Coleman, Dr Yung En Chee, Ms Sharyn Ross Rakesh, Prof Nick Bond
Melbourne’s freshwater ecosystems, like those of other cities around the world, face growing threats from urban growth and climate change. Sound knowledge of current ecological status, key threats, likely future condition, and management actions most likely to protect or improve the health of waterways is vital. Developing this capacity is challenging as greater Melbourne includes >20,000 kilometres of waterways in catchments with substantial climatic, physiographic and land use variability.
Working together, Melbourne Water, the Waterway Ecosystem Research Group (University of Melbourne) and the Centre for Freshwater Ecosystems (La Trobe University) co-developed and applied an innovative approach to identifying waterway management priorities for Melbourne’s Healthy Waterways Strategy 2018—the plan for stakeholders and community to work in partnership to maintain and improve the environmental, social, cultural and economic condition of waterways across Melbourne. Central to this were habitat suitability models for instream biota (aquatic macroinvertebrates, fish and platypus) that drew on >20 years of biological monitoring data. These models allowed us to estimate current biodiversity values at 8,000+ stream reaches across the region, make predictions of how those values are likely to change under projected future scenarios of urban growth and climate change, and quantify expected benefits of specific management actions or combinations of actions. These models helped us identify the most cost-effective management action at any given reach. We then analysed this map of cost-effective actions with spatial conservation prioritisation software (Zonation) to rank all 8,000+ reaches showing where we should optimally act first to protect and improve aquatic biodiversity.
Model predictions, analyses and maps informed multiple co-design workshops with a broad range of stakeholders where modelling outputs were combined with local knowledge and expertise to agree on priority actions and 50-year environmental outcome targets. This project demonstrated how spatially-explicit habitat modelling, action prioritisation and a whole-of-landscape approach can help us strategically understand threats and identify priority actions that give us the best chance of protecting our waterways for future generations.