Rescuers were trying to save scores of pilot whales on Friday in a remote bay in New Zealand, where some 300 carcasses littered the beach after one of the country's largest recorded mass whale strandings.
The spokeswoman asked volunteers to come by 10am, ideally in wetsuits, to help with the refloat at high tide at 11am.
The reasons why these whales have been stranded are still unknown, although the Golden Bay, which has shallow waters, is known for these kinds of incidents.
It is not clear why the whales continue to arrive on the 5km-long (three mile-long) beach on Farewell Spit, next to Golden Bay.
Sources from the Ministry of Conservation said that it was estimated that a total of 416 whales were beached on Thursday night in a sandy area known as Farewell Spit. About three-quarters of the pilot whales were already dead when they were found Friday morning at Farewell Spit at the tip of the South Island.
Sometimes the whales are old and sick, injured, or make navigational errors particularly along gentle sloping beaches.
"There are about 50 [refloated] whales [remaining] offshore, but they're not looking great out there, just milling around", he said last night.
The latest incident in New Zealand was first reported on Thursday evening, but conditions were too unsafe at the time to launch a rescue operation.
Helpers plan to return on Sunday, to help as many healthy whales as they can, braving the threat of sharks and stingrays.
The largest mass stranding of pilot whales in New Zealand occurred at another hotspot - Chatham Islands, where 1,000 whales stranded in 1918, and then in 1985, some 450 individuals landed on the beach.
New Zealand has one of the highest stranding rates in the world, with about 300 dolphins and whales ending up on beaches every year, according to New Zealand marine mammal charity Project Jonah.
In February 2015 about 200 whales beached themselves at the same location, of which at least half died.