In one of Australia’s newest national parks, researchers are assessing how controlled environmental flows help biodiversity – and whether they can save one frog in particular.
Story By Margrit Beemster
A basking red-bellied black snake holds position as three four-wheel-drives bear down on it in Yanga National Park, south-western NSW. After weaving their way along muddy tracks that slice through wetlands fed by the Murrumbidgee River, the vehicles come to a halt. The snake seems unperturbed and takes a while to slither away.
Just as unperturbed, ecologist Dr Skye Wassens, a member of the Declining Amphibian Task Force, pops out of a vehicle, dons waders and plunges into a mix of tea-coloured water, mud and water plants. Net in hand, she skims the surface quickly checking for tadpoles and finds a barking marsh frog tadpole.
Skye, from Charles Sturt University’s Institute for Land, Water and Society, is one of the few scientists in the country studying Australia’s inland frogs, in particular the endangered southern bell frog, which she has been researching since 2000. “It’s a very pretty, cute green frog that sounds like a motorbike,” Skye says. The main purpose of the afternoon’s expedition to ‘The Avenue’ wetlands is to set fyke nets for fish and tadpoles, so she puts the hand net aside and directs her intrepid assistant, honours student Amelia Walcott, who is wading chest deep.
Meanwhile, Dr Jennifer Spencer, an environmental scientist with the NSW Department of Environment, Climate Change and Water (DECCW), counts the waterbird species in the area, with binoculars in hand. Other than coots, ducks, egrets and ibis, she finds the nests of two white-necked herons, a good sign that the inland waterbirds are breeding again.
After the traps are placed at The Avenue, it’s on to Mercedes Wetlands, a much bigger and more open wetland. The scientists drive through saltbush growing on red sandy soils where sheep once grazed, and past a deserted house and outbuildings on the banks of the Murrumbidgee. Late in the day they return to what used to be the station manager’s house at Yanga.
“We go out each night with big spotlights and listen for calls of frogs so we can identify the different species,” Skye says. “We also do counts of adults and tadpoles so we have an idea of how well they are breeding.” The frogs are also screened for chytrid fungus, thought to be the main cause of the decline and disappearance of many frog species in Australia.
This story excerpt is from Issue #75
Outback Magazine: Feb/Mar 2011
