PERTH, Australia >> Nearly 100 pilot whales stranded themselves on a beach in western Australia Tuesday, and about half had died by Wednesday morning, despite the efforts of wildlife experts and volunteers to save them.

The pod of long-finned pilot whales was first spotted swimming near Cheynes Beach east of Albany on Tuesday morning.

As the day progressed, the pod began moving closer to the beach, sparking the concern of conservation officers. By 4 p.m., a large stretch of the shoreline was covered in beached whales.

Western Australia state’s Department of Biodiversity, Conservation and Attractions set up an overnight camp to monitor the whales.

Peter Hartley, a manager from the department, said they had counted 51 whales that had died overnight.

“We still have 46 whales still alive, and that will be our focus today — to get them back into the water and encourage them to head off into deeper water,” he told the Australian Broadcasting Corp. “We are optimistic that we will save as many as we can.”

The team tasked with helping the whales includes Perth Zoo veterinarians and marine fauna experts. They have been using specialized equipment, including vessels and slings.

Hundreds of volunteers also offered to help out. So many, in fact, that officials said they had enough registered volunteers and urged other members of the public to stay away from the beach.

Wildlife experts said the unusual behavior of the whales could be an indicator of stress or illness within the pod. Pilot whales are highly social animals and often maintain close relationships with their pods throughout their lives.