Oral Presentation NCGRT/IAH Australasian Groundwater Conference 2019

Can metabarcoding provide insights into trophic web interactions underground: a case study from the Yilgarn region of Western Australia. (225)

Nicole E. White 1 2 , Mattia Saccò 2 3 , William F. Humphreys 4 , Alison Blyth 2 3
  1. Trace and Environmental DNA laboratory, School of Molecular and Life Sciences, Curtin University, Perth, WA, Australia
  2. Curtin University, Bentley, WA, Australia
  3. WA-Organic Isotope Geochemistry Centre, The Institute for Geoscience Research, School of Earth and Planetary Sciences, Curtin University, Perth, WA, Australia
  4. Subterranean Biology, Western Australian Museum, Perth, WA, Australia


Subterranean ecosystems host a vital and highly adapted invertebrate aquatic biota which play a key role in sustaining groundwater ecological functioning and hydrological dynamics. However, functional biodiversity studies in groundwater environments, the vastest source of unfrozen freshwater on earth, are remarkably scarce.

Design and Methodology

To fill this gap, we propose to dig into the field of groundwater trophic ecology via multi-locus metabarcoding analysis to potentially elucidate trophic web interactions (food webs) and the associated gut microbiome. Stygofaunal specimens were collected from a well-known biodiversity hotspot, the Sturt Meadows calcrete in Yilgarn region of WA. Sampling campaigns were carried out during the dry (LR) and the wet (HR) seasons with the goal of comparing ecological trends within different rainfall conditions.


Preliminary results on a small subset of samples support the possibility of opportunistic feeding of beetles on beetles (Paroster macrosturtensis, P. mesosturtensis, P. microsturtensis) and the sharing of bacterial Families within the gut microbiome of these species, which may be associated with microbially-mediated carbon inputs (gamma and proteobacteria). Further work to expand on these findings is currently underway. Metabarcoding results also highlighted scavenging as a driving force shaping beetles’ feeding habits.


This study, although in its infancy, may provide untangling of stygofauna food web dynamics and stress the importance of the synergy between microbes and invertebrates in calcretes. This is of importance to understand the groundwater functioning and model future affections linked with climate change such as aridification and loss of biodiversity.