Ms Liesel Morgan, Dr Angus Lawrie, Dr Joel Huey, Ms Jessica Delaney, Mr Christopher Hofmeester
1Biologic, East Perth, Australia, 2Trace and Environmental DNA (TrEnD) Laboratory, School of Molecular and Life Science, Curtin University, Bentley, Australia
Biography:
Liesel is a geneticist and invertebrate ecologist at Biologic, working primarily in identification of fauna through molecular techniques. Liesel's experience includes several years as a genetic technician, development of non-invasive subsampling techniques and extensive field survey experience for short-range endemic and subterranean invertebrates.
Abstract:
Most waterbodies in remote arid regions hold water on a seasonal or episodic basis. These waterbodies primarily support aquatic invertebrates that have desiccation-resistant life stages, allowing them to persist during extended dry periods. In the absence of water, the biological communities within these habitats are currently monitored by collecting and rehydrating sediments which contain desiccation-resistant eggs. However, the process of rehydrating, harvesting and identifying the emergent taxa is time intensive. Environmental DNA metabarcoding (eDNA) could be used to survey the species present using sediment samples from dry lakes. Here we explored the utility of eDNA to assess the biodiversity of aquatic invertebrates within dry lake sediments and how these results compare to the results of rehydration experiments.
Sediments were collected from six sites at Lake Way, Western Australia. For each site, two different DNA extraction protocols were used: directly extracting DNA from sediments and using the Onbé-Marcus method (sugar flotation) to concentrate eggs onto a paper filter for extraction. For each site a standard rehydration trial was also undertaken. Compared to a custom DNA sequence reference library, the sugar flotation samples performed much better than soil sediment extractions alone. In addition, all but one taxon was identified in both the rehydration trial and in the metabarcoding of sugar flotation methods. Sugar flotation metabarcoding of temporary waterbodies sediments presents an efficient way to assess biodiversity of aquatic invertebrates.