Toby's Inlet WA: More than a quarter of whales stranded on Aussie beach now dead - as rescuers rush to save the survivors

Authorities have launched a desperate rescue effort following a mass stranding of more than 100 pilot whales on a West Australian beach, with more than two dozen already dead.

The whales have been beached at Toby's Inlet near Dunsborough, about three hours drive south of Perth, with 26 dying.

There are four pods of whales spread across 500 metres of beach with another two pods of about 130 animals offshore in the ocean. 

Geographe Marine Research chair Ian Wiese told the ABC he saw many of the dead creatures, describing the scene as 'terrible'.

'The others are just thrashing around and we'll have many deaths in the next few hours,' he said.

Rescuers are currently mounting a desperate rescue effort after a mass stranding of up to 160 pilot whales on a West Australian beach

Rescuers are currently mounting a desperate rescue effort after a mass stranding of up to 160 pilot whales on a West Australian beach

Parks and Wildlife Service Western Australia posted on Facebook to alert the public of the stranding, with Department of Biodiversity, Conservation and Attractions (DBCA) staff joining with Perth Zoo vets to try and move the animals back into the water.

'We know people want to help but we asked that people please do not attempt to rescue the animals without direction of DBCA staff as this may cause further injury, and distress to the animals and hinder a coordinated rescue effort,' the post read.

'The highest priority at mass whale stranding events is always human safety followed by animal welfare. We want all staff and volunteers to go home safe.'

Another researcher, Chris Burton, told ABC Perth he is still optimistic some of the whales will be saved as volunteers stand in the ocean splashing water on their backs.

'As long as we can see them breathing and people can roll them up so that they can breathe and are not breathing water and put water over their backs, that helps a lot,' he said.

The mass stranding follows a similar event at Albany further south on the WA coastline in July last year. 

In November 34 pilot whales were also found dead at Bryans Beach, 140km northeast of Hobart.