Rescuers were overjoyed today when a lone whale was found alive among hundreds of carcasses in a remote harbour on Tasmania's rugged western seaboard.

This takes to 110 the number of sea creatures that survived a mass stranding in southern Australia.

Around 470 pilot whales become stuck in Macquarie Harbour last week, sparking a major effort to save the animals.

It was "absolutely remarkable" another whale was found alive six days after the pod was first discovered, a Tasmania environment department spokeswoman told AFP.

She said the whale has now been taken back out to sea.

More than 100 rescuers toiled for days in chilly waters to try and save the whales.

"There has been a tremendous team effort and this combined commitment has allowed us to get as many whales as we can back out to sea," Parks and Wildlife Service manager Rob Buck said of the "complex rescue".

With more than 300 carcasses spread across a 10-kilometre area, authorities shifted their focus to a mass sea burial as they dispose of the remaining carcasses.

Boats have begun towing the dead whales into the open ocean, where they will be released over several days.

Authorities have warned that more whales could be found in the area, with some animals likely to become beached for a second time.

The causes of mass strandings remain unknown, but some experts have suggested the pod may have gone off track after feeding close to the shoreline or by following one or two whales that strayed.