Critically endangered spotted tree frogs hop back into Kosciuszko National Park

80 critically endangered Spotted Tree Frogs have been released into Kosciuszko National Park (Alex Pike)

The fight is not over for the spotted tree frog, a species trying to bounce back from the brink of extinction within the NSW Snowy Mountains.

Eighty frogs have been released into Kosciuszko National Park, marking the first release of the species since they were severely impacted by the Black Summer bushfires.

NSW Environment Department senior threatened species officer David Hunter has been leading a program to save the spotted tree frog from extinction since the early 2000s.

"When the spotted tree frog looked like it was going to disappear from NSW, we established a captive breeding program at the Amphibian Research Centre in Victoria," he said.

"In a tank captive environment, they recreated the high-altitude, fast flowing stream that the spotted tree frog lived in and bred."

David Hunter helped release the 80 frogs back into the wild. (Supplied: Alex Pike/Department of Planning and Evironment)

The species population has been significantly reduced by the amphibian chytrid fungus.

Mr Hunter said the frogs had been released from captivity into the wild since 2005, but they continued to die from the fungus.

A small population of the species was thriving in Kosciuszko National Park in the lead-up to the 2019-2020 Black Summer bushfires, before being decimated by the blaze.

Despite the setbacks, reintroducing the conservation program has given Mr Hunter hope for the species' future.

Eighty critically endangered spotted tree frogs have been released into Kosciuszko National Park. (Supplied: Alex Pike/Department of Planning and Environment)

"We're trying to deal with this threat of disease, but we also need to maintain habitat," he said.

Bouncing back

The spotted tree frog is not the only amphibian conservationists are trying to save.

One hundred critically endangered southern corroboree frogs were released into the national park in March.

Spotted tree frogs only grow up to 6 centimetres in length. (Supplied: Alex Pike/Department of Planning and Environment)

Jodi Rowley, an amphibian biologist at the Australian Museum and University of New South Wales, said it was a credit to conservationists for seeing the work through.

"To have these 80 frogs back in the wild, and hopefully thriving and helping boost their population numbers, is fantastic," she said.

Time will tell if the spotted tree and corroboree frog species thrive in the wild, with winter just a few weeks away.

The spotted tree frog is considered fundamental to the ecosystem in NSW upland rivers. (Supplied: Alex Pike/Department of Planning and Environment)

"This is a good time to do it before it gets too cold," Dr Rowley said. 

"These are a couple of frog species that need our help the most.

"They're so important in our ecosystem ... and they're a part of our heritage as well."