80 whales stranded on rocks in Tasmania

About 80 pilot whales have been stranded on rocks on Tasmania's remote west coast just a week after 53 of the giant mammals beached themselves on the island and died, an official said Saturday.

The whales were discovered around mid-morning and a helicopter flew over the area but it would take a team of about 10 rescuers until Sunday to reach the pod, said state government spokesman Warwick Brennan.

"It appears at this stage the majority of the whales are dead," Brennan said.

"Possibly 11 whales are still alive but they've all been battered about on the rocks."

The difficult terrain meant there was grave concern about the ability of rescuers to save the surviving whales, he said.

Pilot whales can reach up to 20ft and weigh up to three tonnes.

Exactly a week earlier, 64 of the mammals, many of them mothers and calves, were found stranded on Anthony's Beach on the southern Australian island.

Rescuers managed to save 11, hauling them onto specially-modified vehicles and driving them to a nearby beach for release into the sea.

Tasmania's Parks and Wildlife Service said Monday satellite tracking devices fitted to five of the rescued whales indicated that the animals were swimming freely in deep water in Bass Strait.

Whale strandings are not uncommon in Tasmania but why they occur remains the subject of scientific debate.