As many as 135 out of 150 whales that washed ashore on Western Australia’s Hamelin Bay have died. Rescuers are trying to save the remaining mammals.

A fisherman noticed the stranded pilot whales around 6 am local time (3.30 am Indian Standard Time) and alerted authorities, the Sydney Morning Herald reported.

“Unfortunately, most of the whales beached themselves on dry land overnight [on Thursday] and have not survived,” rescue team leader Jeremy Chick said according to AP. “Rescue operations will be hampered by deteriorating weather conditions and we need to ensure the safety of everyone involved before we move the whales.”

Locals and tourists were warned to stay away from the water given that the dead whales could attract a large number of sharks, Reuters reported.

A part of the Hamelin beach was closed to public, The Guardian reported.