Happy end to whale tale - but stranding cause a mystery

PERTH - It is still unknown why a pod of more than 100 whales stranded themselves on a beach south of Perth, a rescue effort coordinator said today.

Most of the mammals had beached themselves yesterday at two sites near Busselton, 230km south of Perth and the rest had been in very shallow water, with authorities fearing they too would become stranded.

Hundreds of people equipped with wetsuits, buckets and shovels responded to an urgent call for assistance from the Department of Conservation and Land Management (CALM).

Mark Pittavino, who coordinated the department's rescue effort, said more than 1500 people were involved.

The whales were back in deeper water last night, he said.

"We herded the whales back out to sea," he told the Seven Network today.

"That went very successfully, very smoothly and the boats returned at seven o'clock last night after having stayed with the whales for 30 kilometres.

"They moved the whales out beyond Cape Naturaliste, which is the point where we were hoping to be able to get the whales to."

But it was still not known why the whales had beached themselves.

"We don't know why this particular stranding happened, we would dearly like to know," Mr Pittavino said.

"With every stranding we make efforts to try and investigate the possible causes, that's one of the reasons we had wildlife officers with expertise brought down to assist with the rescue and we had ... four local vets to help with that.

An autopsy performed on the one whale that perished could provide some clues, he said.

"Whale rescues of course happen regularly worldwide and as far as I know it's not been possible to pinpoint a specific cause (of strandings).

"Beach stranding maybe unique in its own particular way, but whether there's any commonality between the strandings we're yet to see."

The department plans to deploy a spotter plane today to check the coastline.

- AAP