Australian authorities are racing to save dozens of pilot whales and a small pod of dolphins beached on an island.
The mammals have stranded themselves on King Island, in the Bass Strait between the mainland and the southern state of Tasmania.
Reports say about 140 out of nearly 200 whales have already died.
More than 400 whales have died in Tasmanian waters in recent months, in a phenomenon for which scientists still have no definitive explanation.
The 194 pilot whales and half a dozen bottlenose dolphins became stranded on Naracoopa Beach on King Island on Sunday evening.
Chris Arthur, of Tasmania's Parks and Wildlife Service, told the Australian Broadcasting Corporation that 54 whales and seven dolphins were still alive.
"It's amazing, some will die straight away, some will survive for days," he said.
"These are fairly robust animals, pilot whales, we experienced that in the past. While they're alive there is a chance," he said.
Local residents joined rescuers in trying to keep the animals wet and finding ways to move them out to open water. More than 100 King Island residents have volunteered to help the efforts.
More than 150 pilot whales died after beaching themselves on Tasmania's remote west coast in November and 48 sperm whales died in January on a sandbar off Perkins Island.
Mass strandings of whales occur periodically in Australia and New Zealand, as the whales migrate to and from Antarctic waters, for reasons that are not entirely understood.
Theories include disturbance of echo-location, possibly by interference from sound produced by human activities at sea.