Fires burning around NSW have razed koala habitats so extensively "we will probably never find the bodies", an ecologist has told a parliamentary inquiry.
The NSW upper house inquiry on Monday held an urgent hearing into the state's koala population and habitat after this season's unprecedented bushfires burned millions of hectares.
Some 90 fires continue to burn across the state with almost half uncontained.
Nature Conservation Council ecologist Mark Graham told the inquiry that koalas in most instances "have no capacity to move fast enough to get away" from fast moving fires.
"The fires have burnt so hot and so fast that there has been significant mortality of animals in the trees, but there is such a big area now that is still on fire and still burning that we will probably never find the bodies," Mr Graham said.
The crown fires which have torn through broad expanses of NSW north coast forest - a known biodiversity hotspot - were unprecedented.
"We've lost such a massive swathe of known koala habitat that I think we can say without any doubt there will be ongoing declines in koala populations from this point forward," Mr Graham said.
North East Forest Alliance president and ecologist Dailan Pugh says at least 2000 koalas may have died on the north coast.
Mr Pugh in a submission says since July fires have burnt more than 1.6 million hectares of the northeast NSW bioregion including 24 per cent of koala habitat.
Eight koala populations have had between 73 and 90 per cent of their habitat burnt, "leaving them in particular danger of imminent collapse," Mr Pugh wrote in the report.
Experts in 2012 estimated there were 8400 koalas on the north coast.
"Based on habitat loss it is likely that over 2000 koalas have died either in the fires or from starvation and dehydration since, though the actual numbers could be far greater," Mr Pugh said.
Science for Wildlife executive director Dr Kellie Leigh told the hearing there was no resources or planning in place to save koala populations in the Blue Mountains from fires currently threatening the region.
"We're getting a lot of lessons out of this and it's just showing how unprepared we are," Dr Leigh said on Monday.
"There's no procedures or protocols in place ... even wildlife carers don't have protocols for when they can go in after fire."
While 20 koalas have been taken into care "hundreds and hundreds" are being lost to fires in the Blue Mountains, she said.
Port Macquarie Koala Hospital's clinical director Cheyne Flanagan said the number of koalas lost in the recent fires combined with the likelihood of further losses over the summer means the hospital's local population could have declined by up to 85 per cent.
"This would then class the koala of the mid-north coast as critically endangered - 10 years ago we had the biggest coastal population of koalas on the eastern seaboard," Ms Flanagan told the hearing.
Hospital president Sue Ashton in October estimated at least 350 koalas would have died in a bushfire in Crestwood based on a predicted 60 per cent mortality rate.
Some 40 koalas have come to the hospital from the fireground but "it's nothing" compared to how many animals were known to be in the area, Ms Flanagan said.
© AAP 2019