Greater Brisbane Platypus eDNA Surveys Project
Plotting platypus distribution one water sample at a time
© Tamielle Brunt
As Greater Brisbane grows in urbanisation, the pressures placed on freshwater ecosystems and the resources that platypuses need to survive also increase.
Noticing a decline in reported platypus sightings, in 2016 Wildlife Queensland initiated this project to use a new and exciting monitoring method, called environmental DNA (eDNA), to sample waterways for evidence of platypuses. Funds raised from the PlatyCount 2016 campaign appeal helped establish the project, which aims to:
- accurately identify platypus presence in selected waterways using the eDNA method
- establish a longitudinal platypus survey in key locations across Queensland
- identify platypus distribution changes over time
- determine habitat quality in association with platypus presence.
Since launching with 66 sites sampled, the project has now grown to have sampled 200+ sites across 67 waterways in 5 Local Government Areas. The team works closely with local councils, researchers and citizen scientists.
This eDNA program is crucial for monitoring this elusive species and has revolutionsied how PlatypusWatch Network project officers identify population strongholds, increasing our understanding of platypus distribution within the state.
Project Officers Tamielle Brunt and Hannah Thomas in the field.
Projects Manager Matt Cecil taking a water sample.
Our 2022 eDNA survey collaborations with three councils resulted in highlighting waterways that are strongholds for platypus populations, even after 2019’s drought, 2020’s fires, and the more recent floods. The Moreton Bay region, particularly, has had consistently positive eDNA detections over the years. Platypus populations are also persisting in the North Pine and South Pine Rivers, despite visible signs of erosion and sedimentation in the urban areas of these catchments.
What is eDNA?
Video created by EnviroDNA
All animals shed DNA into their surrounding environment as they slough off skin and hair cells and leave other body secretions; this is called eDNA. Researchers can collect samples of water or soil from these environments to detect what lives there.
The semi-aquatic platypus spends over 10 hours a day in the water. They shed cells while swimming and we can collect it in a water sample. These samples tell us whether platypuses are present or absent, but they cannot tell us how many individuals are there or their exact locations.
Mapping these monotremes
Wildlife Queensland has been working with Australian ecological research and services consultancy BioGeo to map the distribution of platypuses in Queensland. Using both observational data from the community and presence/absence data from eDNA, BioGeo is developing a model to pinpoint the habitat niche of the platypus, which helps focus conservation efforts by identifying where platypuses are likely to reside or where reintroductions would have the greatest likelihood of success.
In conjunction with eDNA sampling, we assess habitat quality at each site, including features that are preferable to platypuses, such as high stable banks, vegetation cover, pool depth and cobbled substrate, as well as overall waterway health.
Each site is scored on a Habitat Quality Index, which allows us to identify sites or areas that require rehabilitation. Some areas close to urbanisation are vulnerable to erosion and pollution; therefore, we can take action to reduce further degradation of platypus habitat.
PlatypusWatch e-DNA Tracker
This web map highlights the results from eDNA samples taken from 2016—2020, along with information about each site, the number of copies of DNA found there, and when they were collected. Overlapping grid cells are coloured according to the mean number of copies of platypus DNA at each site across the grid cell and across years. The map also includes data from the Global Biodiversity Information Facility (GBIF) of recorded sightings of platypus over a 20-year period, from 1998 to 2018.
This ongoing project will continue to:
- raise awareness about the platypus, its threats, and its conservation needs
- collect and collate observational and water sampling data on platypus populations
- encourage collaborations and engage local residents and citizen scientists in hands-on conservation efforts to rehabilitate waterways and support platypus populations
- expand the eDNA project throughout the state of Queensland
- advocate for increased protection of platypuses in Queensland through local and federal regulations.
Environmental DNA sampling has enabled PlatypusWatch to work closely and quickly with stakeholders to inform conservation actions and management decisions, such as areas to be rehabilitated for platypuses. With just a simple water sample sent to a lab, we can now tell whether platypuses are present or absent from particular waterways.
Partners & sponsors
- Ipswich City Council
- Logan City Council
- Moreton Bay Regional Council
- Brisbane City Council
- Redland City Council
- Brisbane Airport Community Funds