Developing eDNA methods to detect Top End animals Go Back

Animals leave DNA traces of their presence in hair, skin, urine, faeces, sperm and eggs that are shed into their surrounding environment. This DNA can be found in the environment for a short time even after visible traces have disappeared, and is called eDNA. Early studies have demonstrated that eDNA from terrestrial animals can be detected in soil or in waterbodies where they drink or bathe. More research is required to determine which terrestrial species can be readily detected, to develop species-specific probes, to identify practical sampling and analytic methods and to know how to appropriately interpret results.

This project is investigating the use of eDNA to detect a key terrestrial animal species in the Top End. The approach is being trialled on the endangered Gouldian Finch with field validation using water samples from sites where the abundance of finches is closely monitored. After a successful trial for the Gouldian Finch, stage two of the project will compare eDNA test performance against existing survey methods under a major government program assessing biodiversity values in remote, data-poor regions. This will allow both validation and an assessment of cost-effectiveness and potential complementarity.

This project is:

• developing and validating eDNA probes for the endangered Gouldian Finch
• improving our understanding of the distribution and local occurrence of this threatened species
• developing eDNA sampling protocols that are informing protocols for regional environmental assessments
• testing the extent to which this eDNA method can be used to detect terrestrial animals by comparing its utility and cost-effectiveness with traditional sampling methods. If the eDNA method performs well, it will significantly improve monitoring of key species in remote, data-poor areas.

Project activities

• Analyse existing data to identify whether a suitable probe exists for the Gouldian Finch and if not, develop a suitable probe through DNA sequencing and bioinformatics
• Optimise eDNA probe markers using DNA from other finch species and aviary water samples to ensure the method only detects the Gouldian Finch
• Develop detailed protocols for field sampling, sample preservation, DNA extraction and analysis and data management
• Sample for eDNA in waterholes where finch populations are intensively monitored and validate results against finch monitoring data
• Develop a workplan to test the extent to which the eDNA method can be applied in a regional-scale biodiversity assessment program
• Implement the plan (stage two).

Anticipated outputs

• Report on the potential for eDNA methods to detect key terrestrial species
• Report assessing the use of eDNA for detecting Gouldian Finch, and for other species if stage two goes ahead
• Protocols and training manual for sampling design, sample collection and transport, analysis and interpretation
• Workshops, video, presentations and summary reports
• Scientific publications.

Project update October 2019