Heartbreaking images have shown the aftermath of Australia's worst-ever mass stranding of pilot whales.
An estimated 380 of 470 whales are confirmed to have died after the pod got into trouble in a shallow regional outlet at Macquarie Harbour off Tasmania's coast on Monday.
'We're retrieved 70 whales or thereabouts off the sandbar and released them out to sea,' state Parks and Wildlife manager Nic Deka said on Thursday morning.
There are roughly 20 whales still stranded and fighting for life on the sandbars but their chances of survival are becoming increasingly slim.
Wildlife biologist Kris Carlyon said four would have to be euthanised for welfare reasons.
'These are animals that we've given a chance. We've tried to release them, they haven't done well,' he said.
Scroll down for video
The body of a dead pilot whale is seen at Macquarie Harbour on Thursday in Strahan, western Tasmania after the worst mass stranding recorded in Australia
Rescuers attempted to save the stranded whales - pictured beached along the coastline. An estimated 380 are confirmed dead after the large group came aground near the coast
A whale stranded on a beach in Macquarie Harbour on the rugged west coast of Tasmania is pictured as hundreds of pilot whales die in the mass stranding
A hooded person on the shore looks out at the hundreds of stranded whales on Thursday. Tasmania's largest previous mass stranding involved 294 long-finned pilot whales at Stanley in 1935
Stranded whales are pictured dotted along the shore line near the remote west coast town of Strahan in Tasmania
Crews are now faced with the grim task of collecting carcasses, which are likely to be disposed of at sea if conditions allow.
'As the whales start to decompose, they will bloat and float and with wind and tide, they'll drift,' Mr Deka said.
'They could cause a significant navigation hazard if we don't contain them.'
The mass stranding is the biggest in Tasmania and likely the largest on record in Australia.
It surpasses a 1996 beaching of 320 pilot whales at Dunsborough in Western Australia.
Previously, Tasmania's largest mass stranding involved 294 long-finned pilot whales at Stanley in 1935.
One large group was initially discovered stranded near the harbour's head on Monday, with rescuers on Wednesday spotting 200 dead whales a few kilometres away.
It is thought the two groups were part of the same pod and ventured close to shore to hunt.
'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.
A whale is pictured struggling in Macquarie Harbour on Wednesday. A team of around 60 rescuers - including local fishermen and volunteers - were being forced to 'triage' the whales
'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.'
Mr Carlyon, a government marine biologist, said a team of around 60 rescuers - including local fishermen and volunteers - were being forced to 'triage' the whales, working to free those who are in the best condition and easiest to reach first.
Workers have used boats fitted with slings to drag the animals off the sandbar, along with teams of people in the water to guide the animal back into the ocean.
The body of a dead pilot whale is seen at Macquarie Harbour on Thursday. The stranding surpasses a 1996 beaching of 320 pilot whales at Dunsborough in Western Australia
Beached whales most-often died of dehydration as thick coats of blubber designed to keep them warm in the deep sea cause them overheat close to the surface - meaning cool temperatures in Tasmania should keep them alive longer
Rescue teams prepare to head out on the water at Macquarie Harbour on Thursday to help save whales stranded at the regional inlet
Tasmania is the only part of Australia prone to mass strandings, although they occasionally occur on the Australian mainland.
Scientists are unsure why exactly they run aground.
Marine Conservation Programme wildlife biologist Kris Carlyon said the pod may have been drawn into the coast to feed or by the misadventure of one or two whales, which led to the rest of the pod following.sonos sonos One (Gen 2) - Voice Controlled Smart