Efforts to protect the habitat of the endangered growling grass frog at one Victorian treatment plant have been successful, with approximately 140 frogs recorded during recent surveys.
The growling grass frog species is continuing to thrive at Bendigo Water Reclamation Plant in Epsom thanks to the diverse and protected habitat the plant provides.
Coliban Water Executive General Manager Service Delivery Danny McLean said the species had been found in healthy numbers during the latest annual survey.
“Our plant has 67 hectares of lagoons, treatment ponds and dams that have a high biodiversity value,” he said.
“Our treatment lagoons provide an ideal habitat with plenty of algae and ample rocks for protection from predators. This allows the frogs to emerge, feed and bask.”
The plant treats Bendigo’s wastewater for irrigation of public gardens, sporting facilities and farms in the local region, but treated water is also released into the environment to supplement local waterways.
“Both the treatment process and the treated water are providing excellent habitat and environmental benefits for this endangered species,” McLean said.
The most recent survey period ran for two nights, with the use of additional survey techniques allowing for more comprehensive detection of frogs across the plant.
“It involved active searching, the use of audio playback, and small, low cost, acoustic devices called ‘audiomoths’ to record frog calls at optimal times,” McLean said.
“Growling grass frogs were recorded at 13 of the 23 waterbodies assessed at the plant during the survey periods in the 2020/21 breeding season.
“We’ve seen a positive change in numbers from what was recorded last year, which is fantastic and in line with what was recorded in 2018-19. We’re pleased to see growling grass frogs in promising numbers once again.”
The growling grass frog was once found throughout south-east Australia, but is now only located in isolated populations in central and northern Victoria due to habitat loss, predators and disease.
The survey results are an indication that Coliban Water’s commitment to environmental stewardship and sustainability is proving successful, McLean said.
“One of our Strategy 2030 strategic directions is Healthy People and Environment. This is where our focus will remain. Caring for growling grass frogs at our plant in Epsom is a great example of how policies like this translate into tangible actions,” he said.
“The species is listed as threatened in Victoria and vulnerable under the Environment Protection Biodiversity Conservation Act 1999 and is protected by law.
“We are committed to protecting the species and give special consideration for its habitat when planning projects at the plant or making significant changes to our operational activities.”