• Charles Sturt University researchers will use environmental DNA (eDNA) to assess how estuarine fish communities respond to consecutive extreme events of drought, bushfire, and flood
• The estuaries are the Hastings on the NSW Mid North Coast, and the Shoalhaven and Wagonga on the NSW South Coast
• The researchers will deliver community workshops about how to conduct present-day ‘citizen science’ sampling using eDNA methods to collect water samples from the three estuaries

A Charles Sturt University research team will utilise historical environmental DNA (eDNA) samples to assess how estuarine fish communities respond to consecutive extreme events of drought, bushfire, and flood.

The team is led by Dr Jessica Tout-Lyon, Lecturer in Ecology and early career researcher in the Charles Sturt School of Agricultural, Environmental and Veterinary Sciences in Port Macquarie and the Charles Sturt Gulbali Research Institute of Agriculture, Water and Environment.

Dr Tout-Lyon (pictured left) is guiding this large and highly collaborative project with a diverse group of stakeholders in regional NSW.

The stakeholders include First Nations and recreational fishers, not-for-profit community-based conservation groups such as OzFish and Landcare, researchers from universities including the University of Technology Sydney and the University of Newcastle, and researchers from state government NSW DPI Fisheries.

Last year, Dr Tout-Lyon received a NSW Department of Primary Industries Recreational Fishing Trust Fund grant of $156,525 for research in 2023-25. Her previous research has focused on using molecular tools to study the microbial ecology of coral reefs and potential pathogenic bacteria during coral bleaching events.

Dr Tout-Lyon’s recent research focuses on developing molecular tools to detect the distribution of the endemic and endangered Manning River Turtle which have been greatly reduced due to habitat loss, feral animal predation and consecutive extreme weather events such as drought, fire and flood as well.

The researchers will utilise the historical weekly eDNA samples previously collected from three NSW estuaries between 2018-2020 by local oyster farmers as part of the research conducted by project collaborators Dr Penny Ajani and Professor Shauna Murray from the University of Technology Sydney to explore how recreational fish assemblages were impacted by consecutive extreme events of drought, fire and flood.

The estuaries are the Hastings at Port Macquarie (Birpai Country), the Shoalhaven near Nowra (Jerrinja and Wandi Wandian Country), and the Wagonga at Narooma in Eurobodalla Shire (Yuin Country) on the NSW South Coast.

Dr Tout-Lyon has previously said anything that has DNA or leaves DNA in the environment can be studied if we have the right tools to do so.

“Using eDNA will also allow us to explore the impact of climate change, where warmer sea surface temperatures extend further south, resulting in the potential ‘tropicalisation’ of recreational fish assemblages,” Dr Tout-Lyon said.

A Charles Sturt University honours student Mr Seb Roe will be working with OzFish to engage recreational and First Nations fishers in the local estuaries to participate in present-day eDNA sampling of water to study the fish communities in the same three estuaries.

“We are hoping this will demonstrate the importance of involving citizen scientists in collecting samples for long-term bio-monitoring programs in estuaries,” Dr Tout-Lyon said.

“The present-day findings using eDNA sampling methods will be compared to traditional fish survey methods using Baited Remote Underwater Video stations (BRUVs) led by our partners at NSW DPI Fisheries to get a better comparison of the two survey techniques in NSW estuaries. These results will help to inform the design of long-term biomonitoring programs throughout estuaries in NSW.”

The research has commenced, and the researchers will soon engage with the communities of the three estuaries they will work in with Human Research Ethics approval for the project confirmed.

This will include workshops covering how to conduct present-day sampling using eDNA methods, a field sampling day and follow-up presentation highlighting the results.

Lastly, the researchers are encouraging recreational and First Nations fishers from the three estuaries to complete an online survey about which fish species are important to them in their estuaries.

Dr Tout-Lyon is joined by an all-female early- to mid-career research team from CSU including Dr Amina Price, Dr Nicole McCasker and Dr Elise Furlan in the Charles Sturt Gulbali Institute, with Dr Peta Jeffries in the Charles Sturt School of Indigenous Australian Studies. Dr Furlan is also at the University of Canberra.

Professor Lee Baumgartner Executive Director of the Charles Sturt Gulbali Institute and Associate Professor in Biology Paul Humphries in the Charles Sturt School of Agricultural, Environmental and Veterinary Sciences will provide additional expertise in fish biology, ecology and migration.

Locally-based fishers in the Hastings, Shoalhaven or Wagonga estuaries are encouraged to get in touch with their local OzFish chapter to find out how they can get involved in this project and the present-day research using eDNA methods to detect fish in their estuary.

The Charles Sturt researchers have formed a collaborative partnership with researchers and stakeholders from diverse sectors: 

• Uncle Richard Dacker from the Guulaguba Barray Aboriginal Corporation, Birpai Country

• Professor Shauna Murray and Dr Penny Ajani from University of Technology Sydney

• Ms Taylah Kirk and Mr Ryan Lungu from OzFish

• Dr Meaghan Duncan, Dr Nathan Knott and Dr Matt Rees from NSW DPI Fisheries

• Ms Jessica Leck from NSW Mid Coast to Tops Landcare; and

• Dr Michael Stat from the University of Newcastle