The mammals were spotted on Tuesday in an unusual clustering 150 metres off Cheynes Beach, about 60 kilometres east of Albany.
Later on Tuesday afternoon, the whales started swimming onto the sand, beating their tails, flailing around and lining up side by side.
Parks and Wildlife Services regional manager Peter Hartley said it had been “a pretty trying night”.
“The report this morning has been that 36 pilot whales have died overnight,” he told Today.
“We’re focusing on the 50-odd whales that are still alive today and (will) make every attempt possible to return them to the water.”
Western Australia Parks and Wildlife this morning confirmed 51 whales had so far died, with 46 still alive.
“For safety reasons, members of the public are urged to stay away from the beach,” the organisation posted online.
Cheynes Beach Caravan Park captured vision of the pilot whales in an unusual clustering 150 metres off Cheynes Beach, about 60 kilometres east of Albany, Western Australia. (9News
Wildlife scientist Dr Vanessa Pirotta said more were likely to die despite those efforts.
“When the whale strands on any surface the clock starts ticking off,” she said.
A shark alert was issued for Cheynes Beach due to the mass stranding.
“It is possible dead and injured animals will act as a attractant that could lead to sharks coming close in to the shore along this stretch of coast,” the state government’s Shark Smart advises.
“While it’s not uncommon for sharks to be present off the Western Australian coast throughout the year, people should exercise additional caution.
“Officers from the Department of Primary Industries and Regional Development, along with staff from other agencies are monitoring the situation and providing advice to relevant authorities.”
Staff from the Department of Biodiversity, Conservation and Attractions (DBCA) were on site and monitoring the welfare of the whales overnight.
Additional staff were on the way, including Perth Zoo veterinarians and marine fauna experts, along with specialised equipment, including vessels and slings.
People are urged to take additional caution in the area, adhere to beach closures and stay informed.
Experts were in emergency meetings before making their way to the beach to assist the whales.
A caravan park captured drone vision earlier of the whales huddling together in the water, in what is believed to be pre-stranding behaviour.
DBCA is leading the response and managing the incident.
“We understand the public’s concern at this time and appreciate the offers of support from volunteers,” a spokesperson said.
“However, the safety of the public and the whales are our main priority, so we ask that members of the public do not approach the beach.”
Volunteers are asked not to go to the beach tonight but instead register with the DCBA.
‘Never seen anything like this’
The behaviour of the whales before they were beached puzzled experts and captivated both locals and tourists.
Joanne Marsh from Cheynes Beach Caravan Park said it initially looked like the whales were “caught in a big net”.
“It was really incredible, we didn’t know what we were looking at to start off with,” Marsh told 9News earlier.
“Then when we zoomed in on the photo that we first took, we realised it was a lot of small whales all grouped together and we’ve never seen anything like this before.”
Some visitors made the trip out to see the whales and authorities tracking their behaviour originally thought it was not cause for concern.
The mystery movements are something that some whale experts haven’t seen before.
“Our staff from Albany went out on site to have a look for themselves,” John Edwards from DBCA said earlier on Tuesday.
“It’s a very unusual thing that we’re seeing, we haven’t seen a lot of it before.
“This morning when we saw them they were in a tight circle and they were all facing inward.
“We don’t think it’s automatically a stranding behaviour but clearly any time we get whales that come close to the shore, we keep an eye on it.” http://9news.com.au/