The value of biobanking eDNA samples: mapping freshwater mussels and decapods in Melbourne’s catchments

Dr Andrew Weeks1,2, Dr Tarmo Raadik3, Dr Sue Song1, Sarah Licul1, Dr Rhys Coleman4

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

 

Environmental DNA surveys are revolutionising broadscale monitoring of biodiversity in aquatic environments. Melbourne Water manages over 25,000 kms of waterways and prioritises biodiversity conservation through their Healthy Waterways Strategy. They have invested heavily in using eDNA approaches to monitor key species, including platypuses, fish, and amphibians. Widespread eDNA sampling has been undertaken throughout Melbourne’s catchments from 2016–2018 as part of ongoing research into utilising eDNA methods for species detection. As part of this program, aliquots of extracted eDNA were ‘biobanked’ for future use. Here we demonstrate the value of eDNA sample biobanking by using these samples to quickly map the distribution of freshwater mussels and decapods across Melbourne’s catchments. TaqMan qPCR assays were developed for three freshwater mussel species and 590 eDNA samples from 295 sites were screened using these assays. Results were cross-validated with some physical site validation surveys and Atlas of Living Australia records, with eDNA surveys increasing the known distribution of each mussel species throughout Melbourne’s waterways. Freshwater decapods were screened using a new decapod-specific metabarcoding assay from 790 samples collected at 590 sites. The assay revealed high levels of cryptic variation in burrowing crayfish which were then validated through site surveys and further sequencing of reference samples. The biobank of eDNA samples enabled efficient and cost-effective processing to map the distribution of these key species, highlighting the ongoing opportunities that can result from biobanking.


Biography:

Andrew is an ecological geneticist who specializes in applying genetic principles to the conservation of Australian wildlife. He is a founding Director of EnviroDNA and Cesar Australia, and holds a position at the University of Melbourne as a Senior Research Fellow. Andrew is interested in both the research and application of eDNA methods to different sectors including environmental management, conservation, agriculture and biosecurity. He has been working in the area since 2012, partnering strongly with Melbourne Water initially to understand eDNA sampling and detection methods.