A shark warning has been issued after more than 150 short-finned pilot whales became stranded in WA's south.
About 75 whales have died after beaching themselves, while another 50 are still alive on the beach and a further 25 are in the shallows.
The whales were reported by a commercial fisherman at 6am on Friday about one kilometre north of the Hamelin Bay boat ramp, near Augusta.
Parks and Wildlife Service staff are on-site and vets will assess the health of the surviving animals so authorities can return them to deeper water.
"The strength of the animals and the windy and possibly wet weather conditions will affect when and where we attempt to move them out to sea," incident controller Jeremy Chick said.
"The main objectives are to ensure the safety of staff and volunteers, as well as (ensuring) the whales' greatest chance of survival."
The Department of Primary Industries and Regional Development has issued a shark advice and warn people to avoid the area.
"It is possible the dead and dying animals will act as an attractant, which could lead to sharks coming close into shore along this stretch of coast," the department warns.
"While it's not uncommon for sharks to be present off the WA coast throughout the year, people should exercise additional caution until the stranding incident is resolved."
All beaches between Hamelin Bay and Boranup have been closed.
The largest mass stranding of whales in WA was in 1996 when 320 long-finned pilot whales stranded themselves in Dunsborough.
