At least 25 pilot whales involved in a mass stranding on Tasmania's remote west coast have been guided back out to sea.
Authorities believe about a third of the 270-strong pod have died after becoming stuck on sandbars at Macquarie Harbour on Monday.
Some 60 rescuers braved icy waters throughout Tuesday and used special slings attached to boats to refloat and relocate the whales.
"We accept that we are going to lose some animals. Any whale we can save is a real win," Marine Conservation Program wildlife biologist Kris Carlyon told reporters.
He said whales could be heard calling out to each other.
"It is quite confronting. It's one of the reasons why we do put in such a big effort," Dr Carlyon said.
The number of rescued whales was expected to rise into Tuesday night, but the death count will likely increase with it.
One of the freed whales became stranded again and had to be helped a second time.
Efforts will continue early on Wednesday morning, when an infra-red scan will be conducted via helicopter to confirm the number of survivors.
"In terms of mass strandings in Tasmania, this is the trickiest we've had to deal with," Dr Carlyon said.
Dr Carlyon said pilot whales were a robust species and the rescue would continue as long as there were whales still alive.
He said the whales' chances were being aided by cool and rainy weather which was helping to keep them wet.
Boats from a nearby fish farm were used as part of the mission but members of the public are being asked to stay away from the high-risk operation.
"We're dealing with much colder waters than much of Australia. We're rotating crew and making sure people get time out of the water," Dr Carlyon said.
It is understood to be the biggest mass stranding in Tasmania in more than a decade.
The social pilot whales, which travel in groups of up to 1000, could have been drawn to the coast to feed or because the pod followed the misadventure of a few individuals, Dr Carlyon said.
Australian Associated Press