Fifty pilot whales have died after being stranded on a Coromandel beach.
Seventy-three whales were stranded on Opoutere beach on Sunday night but were not found until 10am today.
Department of Conservation staff and volunteers had refloated 11 whales but another 10 were still stranded.
It was the biggest whale stranding in the area in over a decade. Most strandings in the Coromandel involved individual whales.
The stranding came within a day of two mass strandings in Tasmanian waters within 24 hours.
Fifty-three long-finned pilot whales ran ashore at Darlington Bay on Maria Island this morning.
Parks and Wildlife Service district manager Shane Hunniford said 18 of the whales had died, but 22 had been carried back to the water and every effort was being made to save the 13 still alive onshore.
The rescued whales, including a mother and her calf, were waiting just offshore, he said.
Fire-fighting water pumps were being used to help keep the beached whales alive and crews would stay through the night to keep the animals cool and wet.
"As I'm looking out to sea now I can see seven people holding rescued whales and beyond that there's a police launch out there and there's a mother and calf out there, so we've had a good success rate, we're pretty happy," Mr Hunniford said.
"In terms of degrees of health, some are good, some are not so good.
"If things keep going the way they're going now we're doing all right."
Police, parks and wildlife officers and volunteers were also working to shepherd a pod of dolphins away from the scene, he said.
"The other concern we've got is that we've got a pod of dolphins out in the bay itself and we're a little bit anxious that they might try and get ashore as well," he said.
The stranding was the second in Tasmanian waters in just 24 hours -- a mass beaching of whales and dolphins on King Island, in Bass Strait yesterday resulted in the deaths of 98 animals.
Hopes for the survival of an offshore pod of 17 whales were dashed this morning with the discovery that all had died.
Speaking from the remote Bass Strait island, Tasmanian Department of Primary Industry, Water and Environment (DPIWE) spokesman Warwick Brennan said wildlife officers confirmed this morning that the whales were dead.
The mixed group of long-finned pilot whales and bottlenose dolphins beached on the remote Sea Elephant Beach, north of Naracoopa, yesterday.
The final death toll was 73 whales and 25 dolphins and there were no further survivors in the area, Mr Brennan said.
King Island ranger Nigel Burgess said the scene of the mass stranding was bleak.
"They're all dead and they're starting to wash out on the tide and wind. It's not particularly bright," he said.
He said that wildlife officers had taken tissue samples from the carcasses for further analysis.
More than three quarters of Australia's whale strandings occur in Tasmania.
The most common species to come ashore are the common dolphin, the sperm whale, the long-finned pilot whale and the bottlenose dolphin.
University of Tasmania associate professor Mark Hindell carried out research which found a 10 to 12 year cycle of strandings which would peak around this summer.
He said that while the frequency of strandings followed a somewhat predicable pattern, the causes were unknown.
"That's still one of the great mysteries really, what causes particular animals to strand, or particular groups to strand," associate professor Hindell said.
"There's probably as many different causes as there are strandings.
"I don't think there's any question it's a naturally-occurring phenomenon, it's been happening forever."
A combination of oceanographic factors combined to bring large numbers of whales into Tasmanian coastal waters, leading to an increase in the number of strandings at certain times, he said.
"I think it's remarkable that they're so close together but we know that we're in a period of particularly high strandings at the moment -- there's been a lot of strandings happening for the past 12 months or so.
"I expect it might continue for a little while, and then hopefully, it will drop away again over the next few years."
- HERALD STAFF AND AAP