Dozens of volunteers tried in vain to refloat the whales at high tide on Karikari beach.
The volunteers are surrounded by 43 dead whales that are thought to have washed up on the beach earlier today.
Polly Raharuru-Toby has been on Karikari beach and says only 15 whales are still alive.
"It's just sad to see the whales come up. It's hard to see them die there when we're trying to get them all back out again," she said.
Another attempt will be made to refloat the surviving whales at first light tomorrow.
If unsuccessful they will be lifted into trucks and taken to a more sheltered beach a kilometre away.
Marine mammal specialist Anton van Helden says mass strandings are often triggered by a single whale in distress calling out to other whales for help.
"It's a pretty good survival strategy out in the open ocean, for these oceanic animals, that if an animal's in trouble or ailing in some way, that they essentially communicate with other whales to help, so that other animals come and attempt to buoy them to the surface," he said.
It is not the first time there has been a mass stranding of whales on the beach.
In 1997, 101 whales were stranded on Karikari beach.