Almost 200 pilot whales have become stranded on a beach in New Zealand.
Two dozen of the animals have already died, despite the efforts of volunteers who have flocked to the remote Farewell Spit on South Island to help.
It is feared that more of the whales could die, even if rescuers manage to re-float them.
Andrew Lamason, of New Zealand’s Department of Conservation, said: "We've had plenty times in the past where the pods have gone out to sea and turned around and come back again. We're preparing for a big few days."
The Department of Conservation is working alongside community group Project Jonah, who has 140 volunteers in the Golden Bay area.
If the re-float tonight is not successful, members of the public may be needed there tomorrow to help keep the whales cool and wet until the next high tide.
"People should bring buckets, spades and old sheets. A bus will be put on from Triangle Flat at the base of Farewell Spit. People need to be prepared with sunscreen, hats, water, food and warm clothing if they want to assist. Wetsuits are not necessary," Mr Lamason added.
Whale strandings are common in New Zealand but experts say this is the largest in more than a decade.
They describe Farewell Spit as a whale trap because its shallow waters seem to confuse the animals and reduce their ability to navigate.
