Around half of the pilot whales stranded on a Western Australian beach have now died

WA Parks and Wildlife Service have asked the public not to approach the beach or the pod.

WA Parks and Wildlife Service have asked the public not to approach the beach or the pod as wildlife officers managed the incident. "We ask the public to keep their distance and refrain from approaching the pod," the agency said. Source: AAP / Allan Marsh

Key Points

• Nearly 100 pilot whales stranded themselves on the beach in Western Australia on Tuesday.
• About half had died by Wednesday morning, despite the efforts of wildlife experts and volunteers to save them
• Park owner Allan Marsh suggested killer whales in the area may have caused the animals to cluster closer to shore.

Fifty-one whales stranded on a West Australian beach have died as wildlife experts desperately try to save the remaining 46.

"Rescue efforts for live whales continue," the Parks and Wildlife Service said on Wednesday.

A large pod of long-finned pilot whales was spotted huddling together and swimming perilously close to Cheynes Beach, 60km east of Albany, on Tuesday morning.

As the day progressed, the pod began moving closer to the beach, sparking the concern of Department of Biodiversity, Conservation and Attractions officers.

Moments before the stranding, crews were surprised to see the pod form a loose heart shape in the ocean, which was captured by a drone camera.

By 4pm a large stretch of the shoreline was covered in floundering mammals.

Whale rescue efforts underway, inundated with offers to help

As night approached DBCA Parks and Wildlife Service staff, including Perth Zoo veterinarians and marine fauna experts, arrived and set up camp for an overnight vigil to monitor the welfare of the whales within a safety zone.

Officials initially put the number of whales involved at around 70 before the tally was lifted on Wednesday to 97.

Meanwhile, crews have been inundated by hundreds of offers to help.

"We now have enough registered volunteers and the best way to help is for members of the public to stay away from Cheynes Beach on Wednesday," Parks and Wildlife said on its Facebook page.

There are a number of hazards in the area, including large, distressed and potentially sick whales, sharks, waves, heavy machinery and vessels.

Cause of whales' behaviour unknown

Wildlife experts have speculated the unusual behaviour of the whales could be an indicator of stress or illness within the pod.

Macquarie University wildlife scientist Vanessa Pirotta says it remains a mystery as to why whales strand themselves.

"The fact that they were in one area very huddled, and doing really interesting behaviours and looking around at times suggests that something else is going on that we just don't know," she told AAP.

What sets this event apart from previous strandings is the availability of drone footage showing the animals before they stranded themselves.

Nearly 100 pilot whales have stranded themselves on the beach in Western Australia on Tuesday. About half had died by Wednesday morning, despite the efforts of wildlife experts and volunteers to save them. Credit: AP

"The footage alone of the whales huddled in that area in that type of behaviour is highly unusual, and is an interesting one. These animals are largely an offshore species."

Analysing the drone footage, Dr Pirotta said it could potentially be a sick whale or the pod could have been disorientated but it was unlikely they were trying to avoid predators.

Pilot whales are highly social animals and maintain complex familial relationships with their pods from birth.

"They often have a follow-the-leader type mentality, and that can very much be one of the reasons why we see stranding of not just one but many individuals," Dr Pirotta said.