HOBART, Australia (AP) – Rescuers returned 11 pilot whales to sea Sunday, a day after a pod of 64 mothers and calves were found stranded on a beach in southeastern Australia, wildlife officials said.

A team of 15 government officers and 60 volunteers worked to transport the whales from Anthony’s Beach, where they were found Saturday, to a beach with deeper waters 7.5 miles away on the island state of Tasmania.

Tasmania Parks and Wildlife Services manager Chris Arthur said the whales, which measured up to 9.8 feet long, were successfully returned to sea at high tide Sunday afternoon.

Rescuers said they hope the whales will rejoin another migratory pod once they swim back into the Bass Strait, which separates the island of Tasmania from southern Australia.

Satellite tracking devices were placed on some of the whales and a reconnaissance plane would check their progress on Monday, Arthur said.

When the stranded whales were found, 52 had already died and one died overnight Saturday despite volunteers spending the night pouring water over the animal to keep it from overheating.

On Sunday morning, the surviving whales were hoisted in large slings into specially equipped trucks to be driven to Godfrey’s Beach. Volunteers dragged the slings into the water and waited with the whales for high tide to help them out to sea.

Arthur said samples for scientific research had been taken from the dead mammals and a mass burial would be arranged.

Strandings are not uncommon in Tasmania, where the whales pass by on their migration to and from Antarctic waters. It is not known why whales get stranded.

Pilot whales are members of the dolphin family but are considered to behave more like whales. Because of their social nature and the fact they travel together in large groups, mass strandings can occur.