UPDATE: A catch-and-kill order has been issued for the shark that attacked and seriously injured an abalone diver off the coast of Esperance.
Experienced diver Greg Pickering, 55, was in waters near Poison Creek - part of the Cape Arid National Park - about 180km from Esperance when the shark struck about 10.30am today.
There have been unconfirmed reports from other divers that the shark that attacked was a great white.
Department of Fisheries director-general Stuart Smith said he issued the order because "there is an imminent threat of further attack".
It is not the first time Mr Pickering has been attacked by a shark. In 2004, Mr Pickering survived an attack by a 1.5m bronze whaler while spearfishing with a friend near Cervantes.
Mr Pickering arrived at Esperance Hospital this afternoon after a mercy dash back to land by the crew of a nearby abalone boat who witnessed the attack.
Mr Pickering was treated at the hospital for bite wounds, mainly to his torso, and was stabilised. He also has minor injuries to his face.
A Royal Flying Doctor Service plane transported Mr Pickering to Jandakot airport. He landed about 5.40pm and was taken by ambulance to Royal Perth Hospital.
Fisheries officers are on their way to the attack area with capture gear to use in the surrounding waters as soon as possible.
The Department of Fisheries director-general has issued an order to catch and kill the shark.
The department confirmed that the shark behind the attack was almost certainly a great white, but stressed that it was too early to say how big it was or where on his body Mr Pickering was bitten.
Fisheries boss Stuart Smith said he issued the order for the shark to be killed because he deemed it an “imminent risk” to public safety.
Mr Smith said there was likely to be an influx of people in the area given it was school holidays but many would not have access to phone reception or the internet due to its remoteness.
He said this meant the safest course of action for the department was to try to capture and kill the shark that attacked Mr Pickering earlier in the day.
“There were a number of factors I took into account,” Mr Smith said at a press conference in North Fremantle this afternoon.
“First of all, in terms of whether or not there was a high hazard, I found there was a high hazard given an attack had occurred from a shark which we understand ... was a white shark and therefore a species with a known history of attacking people.
“In terms of risk, I took into account the fact that it’s currently school holidays and there are likely to be people down on the south coast, holidaying, camping and potentially looking to use the water.
“Many of the people that would have been on holiday on the south coast would have gone away to get away from things like mobile phones and electronic devices and therefore wouldn’t necessarily receive alerts they might otherwise get through electronic mediums.
“There is a reasonable likelihood of people entering the water and there is also a reasonable likelihood of there being a shark in the vicinity.
“So I formed the view there is an imminent threat of further attack.”
Mr Pickering works for Esperance-based Southern Wild Abalone, the State's biggest abalone processor, and was collecting the delicacy when he was attacked.
Company manager Marcus Tromp said Mr Pickering was conscious but in shock.
Mr Tromp told thewest.com.au that colleagues on another dive boat rushed to help after the attack.
He was dragged from the water and colleagues tried to stop the bleeding.
“They helped provide first-aid and took the diver’s vessel back to shore and got it onto the trailer,” Mr Tromp said.
He said paramedics met the group onshore.
“It was colleagues helping colleagues," Mr Tromp said.
"In diving or farming or mining, people working in the same field and close-working colleagues would do the same thing.”
Mr Tromp said the diver’s injuries were “substantial" and his thoughts were with Mr Pickering.
“To be conscious and talking is very promising,” Mr Tromp said.
He said Mr Pickering’s family was calm despite the drama.
In 2004, Mr Pickering - believed to have been an abalone diver for more than 40 years - put himself between his friend and a shark when it started attacking.
He was bitten on the leg.
The experienced spear fisherman had another close call in 2009, when the boat he was diving under in Ceduna in South Australia capsized.
Mr Pickering and another deckhand were found by rescue crews in a life raft after about three hours.
It is not known exactly where at Poison Creek Mr Pickering was diving today, but the divers work within five miles of shore.
Abalone are found in water depths of between 2m and 20m.
“The crew on the diver's vessel would have been in shock, and I believe the diver was left on the vessel to keep the injuries stemmed, and the vessel was towed back to meet with the ambulance," Mr Tromp told ABC radio.
Mr Tromp said the men had departed from Poison Creek at Cape Arid National Park, a popular fishing spot, where they often camped for a few days at a time while working, rather than drive for two hours each night back to Esperance.
Poison Creek is only accessible by four-wheel-drive.
A Surf Life Saving spokesman said Esperance’s coast was quite dangerous, with big sharks frequently seen in the area and fishermen often swept off rocks.
There have been five fatal shark attacks in WA since 2011.