How environmental DNA survey methods are informing management of waterways across Greater Melbourne: from long-term research to routine application

Dr Rhys Coleman¹, Dr Reid  Tingley², Dr Tarmo Raadik³, Dr Alistair Danger¹, Dr Andrew Weeks^4,5

¹Melbourne Water, Docklands, Australia, ²Monash University, Clayton, Australia, ³The Arthur Rylah Institute for Environmental Research, Department of Environment, Land, Water and Planning, Heidelberg, Australia, ⁴The University of Melbourne, Parkville, Australia, ⁵EnviroDNA, Brunswick, Australia

Abstract:

Melbourne Water manages approximately 25,000 km of waterways across Greater Melbourne. Fundamental to biodiversity conservation is a comprehensive understanding of species occurrence to prioritise management actions. Whilst Melbourne Water has invested substantially in wildlife detection surveys since the 1990s, coverage of the region using traditional techniques has been constrained (e.g., by cost, time, site conditions, detection sensitivity and safety). Recognising the potential for an eDNA approach to overcome some of these limitations for species detection, Melbourne Water collaborated in several interconnected research projects with The University of Melbourne, Monash University, The Arthur Rylah Institute and EnviroDNA. Commencing with a threatened fish pilot study in 2013, we then secured an Australian Research Council Linkage project between 2015-2018 that investigated: 1) single- vs multi-species detection methods, 2) sensitivity and cost effectiveness compared to traditional surveys, 3) understanding the impact of false positives, and 4) filter preservation. Melbourne Water then embarked on a broad-scale survey at 340 sites with metabarcoding of vertebrates, fish, amphibians and decapods. This exercise (termed ‘Aquablitz’) was critical for demonstrating the potential of eDNA for region-wide aquatic biodiversity surveillance and building confidence for routine adoption. Furthermore, eDNA samples have provided an ongoing resource for targeted investigations of specific faunal groups (e.g., burrowing crayfish, freshwater mussels, platypuses). Long-term, strategic investment in eDNA research has culminated in a regional monitoring program at >1,500 sites (including streams, wetlands and estuaries) to track progress towards targets in our Healthy Waterways Strategy, validate habitat suitability models, and support the identification of future management priorities.

Biography:

For the past 25 years Rhys has worked at Melbourne Water with a focus on waterways research and strategic management planning. Currently, Rhys is the Waterways and Wetlands Research Manager which involves the facilitation and co-ordination of major research programs, review and interpretation of research-generated results for industry relevance, and the communication of these results to industry. Rhys has participated in several collaborative research projects as an industry partner, including ARC Linkage projects, CRCs, and is the co-research coordinator for two major initiatives with the University of Melbourne – Melbourne Waterways Research-Practice Partnership and RMIT University – Aquatic Pollution Prevention Partnership (A3P).