Rescuers in Tasmania are racing to save the few dozen pilot whales still alive following the worst mass stranding on record in Australia.
About 380 of some 460 stranded whales were confirmed dead on Wednesday, although about 50 have been freed from sandbars at Macquarie Harbour on the state's west coast.
Roughly 30 are still fighting for life as rescue efforts enter a fourth day.
"We'll continue working to try and free as many of the remaining live animals as we can," Parks and Wildlife Tasmania manager Nic Deka said.
"There's certainly hope for them but as time goes on they do become more fatigued and their chance of survival reduces."
Wildlife biologist Kris Carlyon said it was definitely the biggest stranding in Tasmania and likely the largest stranding on record in Australia.
It surpasses Tasmania's largest mass stranding of 294 long-finned pilot whales in 1935 at Stanley.
It is also greater than a 1996 event where 320 pilot whales became beached at Dunsborough in Western Australia.
One large group was initially discovered stranded near the harbour's head on Monday, with rescuers on Wednesday morning spotting 200 dead whales a few kilometres away.
Authorities are expected to soon finalise a plan to dispose of hundreds of carcasses.
It is thought the two groups were part of the same pod.
"Pilot whales are incredibly social and maintain strong social bonds with each other and have been known to be found in groups up to 1000," marine scientist Dr Vanessa Pirotta said.
"The ability for them to stick together and follow the leader is something we see often with these animals, which is why it is so heartbreaking."
The freed whales were likely to reform their social group, Dr Carlyon said.
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