Hundreds of koalas are believed to have perished in a bushfire that has ripped through a large area of critical koala habitat, south of Port Macquarie in New South Wales.

Key points: Wildlife experts predict up to 350 koalas may have perished in fires south of Port Macquarie

Wildlife experts predict up to 350 koalas may have perished in fires south of Port Macquarie Fires have burnt out more than 2,000 hectares of bushland and are still burning

Fires have burnt out more than 2,000 hectares of bushland and are still burning The Rural Fire Service says crews will take koala rescuers into the site when it's safe to do so

WARNING: This article contains graphic photos that may distress some viewers.

Staff from the Koala Hospital in Port Macquarie are unable to access the area because it remains off limits due to the continuing intensity of the blaze.

"I think this is just a national tragedy that we potentially have lost an enormous population of animals in the past 24 hours," hospital clinical director Cheyne Flanagan said.

'Not a good day'

Smoke billows out from bushfires over the beach and townships of Forster-Tuncurry in NSW. ( Supplied: Martin Von Stoll )

Ms Flanagan said it was likely at least 350 koalas had died, based on the overall size of the current fire footprint, which is two-thirds of the koala habitat, and a 60 per cent mortality rate.

"Twenty years worth of work at the place. I just feel like walking away, I really do, I'm not going to, but it's just awful," she said.

"These are animals of national significance because they are so genetically different and so diverse."

The fire razed an area south of Port Macquarie that is considered critical koala habitat.

The fire has so far burnt out more than 2,000 hectares of bushland and is continuing to spread.

The Koala Hospital has worried about the potential for this scale of destruction since 2002.

"That area houses the most significant population of koalas in this region," Ms Flanagan said.

The Koala Hospital's clinical director Cheyne Flanagan felt like walking away after the fire ripped through a koala hotspot. ( ABC News: Kirstie Wellauer )

Access to the fireground

Herman Kruse came across a dead koala near the Lake Innes Nature Reserve and said it was heartbreaking to see.

"First little koala we've seen in ages and the poor little bugger's dead," he said.

"I love the koalas and we've just been losing them over a period of time, so to finally see one and the poor little sod's burnt like that is just so sad," Mr Kruse said.

Fire authorities said as soon as it was safe they would escort wildlife experts into the fireground where it was feared hundreds of koalas may have been killed.

James Morris from the Rural Fire Service said crews would do what they could to help when the situation settled down.

"Once that fire starts to die right back down and we feel that it is safe to put them in we'll have firefighters go in with those representatives," Mr Morris said.

"Obviously they can start working on that population to determine whether there has been any loss of koalas or damage to their habitat."

This koala was found in burnt bushland in prime koala habitat, near the village of Lake Cathie. ( ABC Mid North Coast: Emma Siossian )

Maps viewed by Ms Flanagan showed the devastation.

"All the areas that have been burnt, the vast majority was koala habitat and basically hundreds of animals have died in the past 24 hours," she said.

Recovery could take years

A north coast ecologist said the recent spate of bushfires across northern NSW represents a nightmare scenario for koalas.

Stephen Phillips said thousands of hectares of key koala habitat had been lost in recent fires around Rappville, Wardell, Port Macquarie, and Forster.

Dr Phillips said it was likely 60 to 70 per cent of the breeding populations in those areas had perished.

A large male koala was found killed by the fire at Braemer State Forest at Rappville. ( Supplied: Hugh Nicholson )

"You're left with a very small group that survive," he said.

"They've got to re-establish themselves, the food trees have got to grow and recover, and then those animals have got to start breeding to repopulate those areas of empty habitat from which animals have been lost.

"Koalas are not fast breeders, they're very slow breeders."

He said the recovery process could take decades.

"It has certainly set the general recovery objectives of conservation back a long time, probably 10 to 20 years in some instances depending on the scale of the impact," Dr Phillips said.

"Given that some of these fire events are in areas that have been identified by the government's own research as areas of regional koala significance, then these are major losses."

Pushed towards extinction

Australian Koala Foundation chairwoman Deborah Tabart has been lobbying for legislation to protect koalas and their habitats.

She said the bushfire at Lake Innes was just another blow for the native animals.

"I've been in my job for 31 years and I've seen koalas go to extinction just one by one in localised extinctions, and these are the events that make that occur," Ms Tabart said.

A koala being treated at the Koala Hospital in Port Macquarie. ( ABC News: Kirstie Wellauer )

The Australian Koala Foundation has proposed a Koala Protection Act that would protect koala habitats and require careful consideration of the consequences of building developments on koala populations.

Ms Tabart believed government actions, over many years, had contributed to the situation that was putting koala habitats at risk from bushfires.

"Not that I believe you can legislate against fires but, let me tell you, in the old days when we didn't dam all the river systems, when we didn't have dry landscapes, these fires didn't get as fierce," she said.

"It's not just climate change. This is absolute mismanagement of the bush."

Weeks of searching

Ms Flanagan did not think anything could have been done differently to protect the koalas.

"Probably some more controlled burns in winter, but I don't think anything would have stopped the intensity of this fire at the moment," she said.

"There's a high fuel load, we haven't had any rain, it's just every condition under the sun — it's just rife for this to do what it did."

Wildlife rescuers are desperate to check on koalas in burnt-out bushland south of Port Macquarie. ( Supplied: M Fillinger )

Ms Flanagan said there would be weeks of searching ahead, but she did not think they would find too many live animals.

"I don't think we're going to find good results with the koalas, I really don't, but we'll find out," she said.

"We might be lucky, but it's not looking good."