Mr Jake Thornhill1, Dr Michelle Guzik1,2, Dr Mieke van der Heyde3,4, Dr Nicole White3,4
1School of Biological Sciences, University of Adelaide, Adelaide, Australia, 2Environment Institute, University of Adelaide, Adelaide, Australia, 3Subterranean Research and Groundwater Ecology (SuRGE), Curtin University, Bentley, Australia, 4Trace and Environmental DNA (TrEnD) Laboratory, Curtin University, Bentley, Australia
Biography:
Jake Thornhill is a PhD candidate in the School of Biological Sciences at the University of Adelaide. His research focuses on the development of eDNA techniques for application to high biodiversity value groundwater ecosystems.
Abstract:
Groundwater is a vital freshwater resource, yet the ecosystems that occupy these subterranean environments are often overlooked. Stygofauna, aquatic groundwater metazoans, comprise high biodiversity value ecological communities of ancient lineages that maintain groundwater integrity via critical ecosystem services. The Pilbara and adjacent regions of Western Australia (WA) are hotspots of stygofauna biodiversity; however, in this region particularly, these unique communities are vulnerable to industrial impacts. With mandated requirements on industry to minimise environmental impacts on stygofauna, innovations on monitoring methods are essential for improved decision making by regulators. However, under-described taxon groups and incomplete barcode reference libraries (BRL) limit species identification from groundwater eDNA data and constrain adoption of eDNA approaches into monitoring programs. To address the taxonomic impediment, we developed a custom stygofauna BRL for an internationally recognised groundwater ecosystem, Barrow Island (WA), through literature/data review, DNA barcoding, and species delimitation methods. Approximately 490 DNA barcodes for 30 species covering five barcoding loci for were compiled to produce the most comprehensive BRL for Barrow Island stygofauna. For validation, we queried Barrow Island groundwater eDNA metabarcoding data against the custom BRL and GenBank. The custom BRL better demonstrated fine scale identification of stygofauna from eDNA survey data. However, some taxonomic groups were not well characterised, likely due to primer and/or sequencing biases. Our results highlight the necessity of comprehensive stygofauna BRLs and demonstrate the efficacy of eDNA as complementary stygofauna monitoring tool, while acknowledging methods still require development.