By Dr Fleur Stelling - Charles Sturt University

Riverina communities have been successful in recovering the Southern bell frog from the brink of extinction.

It's been another fantastic year for the Southern bell frog population, with exciting signs of continuing recovery thanks to dedicated efforts of Riverina communities and water for the environment deliveries. Last week, the monitoring team from Charles Sturt University working on the Commonwealth Environmental Water Holder’s science program in the Murrumbidgee, were thrilled to hear the unmistakable calls of the frogs and observe large numbers of tadpoles in the Lowbidgee wetlands – a clear sign that their population is recovering well.

These frogs were once abundant across the Southern Murray Darling Basin with populations along the Murrumbidgee extending right up to Canberra.   Rapid population declines in cooler regions were caused by the arrival of the amphibian chytrid fungus, an introduced pathogen that has been responsible for declines of frog populations across the globe.

The impact of the amphibian chytrid fungus however, was less severe in the Riverina due to higher temperatures. Stronghold populations of the frogs in Coleambally and the lower Murrumbidgee remained abundant up until the start of the Millenium drought when water became scarce. The frogs, like many species, were heavily impacted by the prolonged dry conditions and reduced floodplain inundation, during the Millennium Drought. As their habitat dried up and breeding opportunities dwindled, the frog populations declined dramatically.

Since 2009, the local landholders and First Nations managers have assisted with the delivery of Commonwealth environmental water, which has been a cornerstone of the Southern bell frog’s recovery in the Murrumbidgee. Communities have used the water to restore wetland habitats on their lands, vital for the frogs and also the endangered Australasian Bittern, which benefits from the growing frog numbers.

Communities partnering with the CEWH have helped create breeding opportunities during wetter years, and also maintain ‘refuge’ habitats during dry years, ensuring that the frogs have a place to survive when the wetlands dry out. These actions create a more resilient landscape for the frogs, offering them a safe space to grow and breed year after year, no matter how the climate fluctuates.

The continuing recovery of the Southern bell frogs marks a remarkable turnaround. From the brink of ecological collapse during the devastating drought, with the targeted and carefully managed environmental water deliveries, their populations are now continuing to grow.

Monitoring Project Leader, CSU’s Professor Wassens reflects on the progress made.

"The ecological renewal brought by these efforts—and in particular, the flourishing of the Southern bell frogs is incredibly heartening," she said, also acknowledging the key role of local farmers and First Nations group the Nari Nari Tribal Council in collaborating to coordinate water deliveries to the wetlands.

Looking ahead, the future of the Southern bell frog now looks promising. With ongoing efforts and continued support for environmental water, the frog populations will have the opportunity to continue to grow and help restore balance to their ecosystems. The success of the Southern bell frog is an inspiring reminder of how, with careful intervention and collaboration, threatened species can make a comeback—even in the face of significant challenges.