A man has been killed in a shark attack at a popular surfing spot about 270 kilometres south of Perth.

The victim, a 35-year-old man from Margaret River, was attacked just after 9:00am on Saturday near Lefthanders break in Gracetown.

The police say the shark made contact with the board of another surfer before fatally attacking the man.

"From the enquiries we have conducted so far, the shark actually bounced off the board [from] the other surfer, before attacking the other male," acting sergeant Norm Giocas, officer in charge at Margaret River Police Station, said.

"There were other people on the beach and they assisted him on the shore."

The director general of the Department of Fisheries has issued an imminent threat order and sent officers to the area to capture the shark.

But they say it is too early to determine if the animal will be destroyed.

Tony Cappelluti from the department says fishery officers will take several factors into account when deciding what sort of action will be taken.

"I can't make that decision and I can't speculate on what we'll do at the time," he said.

"It just depends on the species of shark - obviously not all species of shark are dangerous or may be responsible for the attack, so obviously those decisions will be made at the time."

Beaches from Umbies to South Point and Huzzas, North Point and the main Gracetown beach have been closed for an initial 24 hours.

St John Ambulance attended the scene and a helicopter was used to move the man's body from the beach due to the surrounding terrain.

Town's third fatal shark attack in 10 years

Surfer Tom Jones says he was at nearby Big Rock beach at the time of the attack and knows of the victim.

"Cop cars rolled up at Lefties and we thought, definitely another shark attack," he said, adding, "I know of him, and he was pretty young to die."

Act Sgt Norm Giocas says locals are mourning the victim's loss.

"Naturally, this is distressing for anyone to see," he said.

"The surfing community in Gracetown and Margaret River is quite a close knit community. They are all in quite a bit of shock."

Saturday's fatal attack is the third in the area in 10 years.

In 2004, surfer Bradley Smith was killed by a great white shark at a beach close to Gracetown and in August 2010 another surfer, Nicholas Edwards, was killed by a shark at nearby South Point.

Last month, abalone diver Greg Pickering was seriously injured in a shark attack while diving in remote waters off Poison Creek beach, 160 kilometres east of Esperance, WA.

He had also survived an attack by a bronze whaler shark off Cervantes, north of Perth, in 2004.

Anyone who sees a shark in the Gracetown area should report it to the police.