eDNA makes a splash

19 October 2021

Author: Tamielle Brunt

Wildlife Queensland’s PlatypusWatch program can now proudly reveal the much-awaited results of eDNA sampling at sites along the Dawson River and tributaries earlier this year.

In June 2021, 19 sites were sampled along a ~60 km stretch of the Dawson River, from Moura out to the Santos property in the west. Sites in four areas (shown left to right in the image above) revealed evidence of platypuses – Isla-Delusion Road Crossing, Tarana Crossing west of Taroom, Kianga River Road crossing north of Theodore, and the Hutton Creek Santos site.

Five sites (green) were positive for platypus DNA in four areas, at Kianga River Road crossing, Isla-Delusion Road Crossing, Tarana Crossing and the Santos sites. One site was equivocal (yellow), meaning the test was not able to prove with certainty that platypus DNA was present.

The results, as shown in the maps at right, highlight the significant distribution of platypuses in the river system.

Although the Platypus Watch team cannot determine platypus numbers from samples alone, these results provide valuable information regarding areas of focus for platypus habitat and connection protection.

Going With the Flow

The flow of the river is of high importance, especially for platypuses to move within the system and mate successfully.

The eDNA results were negative for one area where platypuses were sighted, a discrepancy likely due to water turbidity, which inhibited passing water through the very fine filters and led to less water being collected than typically required to perform the eDNA test. This was a great learning experience, and the PlatypusWatch team is researching better options (i.e. larger filter size) for next year’s sampling.

Maximising the water volume passing through the filter will increase the chance of detecting small fragments of platypus DNA.

A Pilot That Will Foster Further Participation

Overall, the Dawson River eDNA sampling project 2021 was a great start to monitoring platypuses in the Banana Shire region, and the sample sites identified had key features for platypuses, such as native trees consolidating high earthen banks and overhanging vegetation – features important for burrowing, shelter and nesting.

Acting as a pilot study for platypus eDNA citizen science sampling by local communities, this experience will shape how these programs operate in the future.

The PlatypusWatch team looks forward to working with the community to build upon this dataset, which will enable them to better understand how platypuses use this vital system and to ensure they are protected into the future.

HELP OUR PLATYPUSES

Continued monitoring is critical. We cannot protect platypuses if we don’t know they are there. Observational records are as important as eDNA records, as they can help us determine the distribution of a species and fluctuations over time, whether temporary or permanent.

That’s why it’s vitally important that community members report their sightings to the  PlatypusWatch Network.

Each sighting is important for the survival of the species.

  • If you find a dead platypus: They are still highly important for research. Please contact the PlatypusWatch Network as per above.

You can also support platypus conservation through our adopt-a-platypus program.


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Written by Wildlifeqld