River Murray flood creates breeding boom

Flooding in the Murray-Darling Basin has created ideal breeding conditions for many native species, including the threatened southern bell frog.

Scientists hope it will lead to a population boom in the often parched wetlands, where many species are struggling to survive.

"A lot of Australia's native fauna is adapted to take advantage of these flood conditions that were much more common once upon a time," ecologist Rupert Mathwin told AAP on Wednesday.

"The submerged vegetation creates an ideal nursery habitat to support breeding."

The flooding also results in the release of extra nutrients into the food web stimulating growth in the ecosystem.

"It benefits all species," Mr Mathwin, a Flinders University PhD candidate, said.

Water management policies in Australia's largest river system have significantly altered the natural flooding patterns and reduced water flows over the last century.

"Since the lochs have been added it's shifted the way the system works and it requires a level of intervention to support the plants and animals and ecosystems," Mr Mathwin said.

"When we do get flooding it tends to be to a lesser extent and it's shorter lived and they occur less frequently."

Many wetlands and the species that inhabit them now rely on costly pumped water allocations to sustain them in lieu of flooding.

But not all the wetlands in the basin can be inundated with "environmental water" each year, negatively impacting many of the species that rely on them for survival.

"What's happening this year is the floods are giving us all of those environmental services for free and we don't have to prioritise between the wetlands," Mr Mathwin said.

"It's an 'every wetlands wins' kind of a year."

Mr Mathwin hopes it will lead to a population explosion in wetland fauna, including southern bell frogs.

"I'm really hoping it will result in a boom," he said.

"Time will tell and we really have to wait for a year or two of monitoring to trickle to confidently say that it did work.

"But I strongly expect it will result in a large, hopefully not temporary, increase in the population because of this massive amount of extra habitat."

Southern bell frogs are one of the nations's 100 priority threatened species, and are found in NSW, Victoria, Tasmania and South Australia.

They were once common throughout southeast Australia until the 1970s when they started to rapidly decline.

The few remaining populations persist at sites that are regularly inundated by pumped water during their breeding season in the spring and summer.