Dozens of whales have died after several pods washed up on the shore of a beach on the Western Australian coast.

Marine wildlife experts including wildlife officers, marine scientists and veterinarians tried frantically to save the pilot whales stranded on Thursday in shallow waters at Toby Inlet in Geographe Bay.

Four pods of up to 160 pilot whales in total spread across about 500m along the beach, near the town of Dunsborough, in a region popular with tourists.

More than 100 that beached returned to sea, while 31 died, a researcher said.

“There were well over 200 along the beach here and just nearby and there’s 31, I think, deceased – but the rest got away, which is an amazing story,” Ian Wiese told Australian Broadcasting Corp.

“When I first arrived, there was, I think, 160 in the water – almost out of the water – and there were a couple of hundred people who were with the whales, they were trying to comfort them and make sure that their heads were out of the water so they could breathe.

“And then after an hour or so, all of a sudden the ones that were in the water that were still alive left and went out to sea,” Mr Wiese said.

“They may well decide to come back to shore somewhere on another beach nearby or something – that often happens, but we’re hopeful that they won’t,” he added.

The Department of Biodiversity, Conservation and Attractions confirmed the rescue.

In its latest update on Facebook, it said 28 whales that had been stranded on the beach had died.

“A spotter plane has been in the sky looking for the pod that swam out to sea,” the post read.

“There has been no further sightings of the pod this afternoon, which is good news.

“The spotter plane will continue to monitor the area during daylight hours, but we are hopeful that the pod will not return to the shallower water.”

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In July last year, 51 pilot whales died after about 100 washed ashore on Cheynes Beach.

The state experienced its largest whale stranding at Dunsborough in 1996 when 320 pilot whales were involved in a mass stranding.

According to the University of Western Australia, pilot whales are known for their tight-knit social bonds, so when one gets into difficulty and strands, the rest often follow.