Revealing hidden wildlife in the Wolston Catchment through environmental DNA

4 February 2026

A Wildlife Queensland community-powered project uncovers what lives beneath the surface of our local waterways. 

From a sample of creek water, scientists and community members have uncovered an extraordinary snapshot of wildlife living in an urban catchment, including platypus, rakali, turtles, birds, mammals and dozens of aquatic invertebrates. Using environmental DNA (eDNA), the five-year project in the Wolston Catchment is building a clear picture of biodiversity in an area under continual pressure and laying the groundwork for long-term recovery. 

Why the Wolston eDNA project matters 

Environmental DNA is genetic material that animals leave behind in the environment, such as skin cells, hair or faeces. In rivers and creeks, these microscopic traces drift through the water and can be captured in a simple sample. By filtering up to 500 millilitres of water and analysing it in a laboratory, scientists can identify which species are present, or were present recently, without needing to see or disturb them. 

eDNA is now widely used across Australia to monitor full biodiversity suites. It is fast, non-invasive and highly effective at detecting cryptic or elusive species that are often missed by traditional surveys. 

The Wolston Catchment was selected because it sits within a highly modified landscape, shaped by industrial land use, extensive hard surfaces and stormwater inputs. There was also a unique opportunity to partner with a local industry, Omega Chemical who support the project and community.  Understanding the wildlife that persists in these waterways and how communities can help restore them is critical for building long term stewardship and engagement 

Dr Tam and Omega Chemicals staff in the field.

Community science in action 

Year One of the project began with a hands-on eDNA workshop held in September last year at Pooh Corner Environment Centre, hosted by Wolston and Centenary Catchments. Community members were introduced to eDNA and trained to collect water samples correctly. 

Participants then took sampling kits into the field to collect water from 12 allocated sites across the catchment. Samples were sent to EnviroDNA laboratories in Melbourne for multi-species metabarcoding analysis. Staff from local business Omega Chemical also joined the effort, focusing on Bullockhead Creek, an area with known pollution pressures. 

Dr Tam Brunt, who led and implemented the project, said:

“The quality of data we get improves when the community is directly involved. People gain a deeper understanding of their local waterways, and the science benefits from broader coverage across the catchment.”

What the eDNA revealed 

The results painted a complex and revealing picture of life in the Wolston Catchment. 

Across the 12 sites, eDNA detected taxa of 16 native fish species, a native frog species, 14 native bird species, two macropod species, two turtle species, possum, platypus, and rakali. The grey-headed flying fox was also detected, as DNA can wash into the waterway from land or come from overhead. Introduced species were present too, including five pest fish species, cane toads, and DNA from domestic and livestock animals. 

Detection values varied widely. Some species, such as the long-finned eel, were detected at high levels across multiple sites, suggesting a broad distribution. Others appeared only at a few locations, indicating more localised or less abundant populations. Platypus DNA was detected at three sites in the lower section of Bullockhead Creek.  

The project also analysed aquatic invertebrates, also known as waterbugs. Most detections were from Diptera, including midges and flies, which are known to tolerate pollution. When assessed using the SIGNAL waterway health scoring system, the sites averaged around a score of two, indicating severely impacted conditions. 

“These results are not unexpected given land use and stormwater inputs,” Dr Brunt said. “They provide a clear baseline from which we can measure improvement.” 

One eDNA sample.

What this means going forward 

This first year of sampling establishes a crucial biodiversity baseline for the next five years. By repeating eDNA surveys annually, changes in species presence can be tracked as revegetation, stormwater improvements and restoration works take effect. 

Importantly, eDNA data helps guide action. It can highlight areas that support vulnerable or iconic species, identify hotspots for invasive species control, and inform councils and land managers about where protection and restoration will deliver the greatest benefit. 

While eDNA cannot tell us how many animals are present or exactly where they are, it provides powerful evidence to support smarter decisions and long-term planning. 

Healthy creeks support wildlife, improve water quality and strengthen community connections to nature. By combining sound science with community action, we can help restore the Wolston Catchment, one water sample at a time. 

What you can do

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