Western Australian authorities are hunting for the shark which killed a surfer on Saturday, amid questions about whether the great white should remain a protected species.

Ben Linden, 24, was fatally attacked while paddling his surfboard near Wedge Island, 160 kilometres north of Perth.

He was about 100 metres offshore when he was attacked by what witnesses believe was a five-metre great white shark.

It is the fifth fatal shark attack in WA waters in less than a year.

State Fisheries Minister Norman Moore says the trend is distressing and raises the question of whether great white sharks should still be protected.

"We have allocated some $14 million extra to get a better understanding of the great white sharks and the reasons why the fatalities are occurring," he said.

"I wonder if research might tell us that there are now much greater number of great whites than ever before.

Mr Moore says he will write to the Federal Environment Minister Tony Burke to see if there is any evidence to show that the Great White shark population is increasing and, if there is, to lift the protective status.

"They have been protected by the Commonwealth and by the state for about 20 years because they were considered to be a threatened species," he said.

"But, there seems to be a view that there's an increase in the number of great whites within our waters in recent times.

Surfer Ben Linden, who was killed by a great white on Saturday. ( Supplied )

"This is a very distressing event and to add to the previous four fatalities, it is of great concern to me and to the fisheries department, indeed the Government as a whole.

"We have done everything so far in the last little while to deal with the issues as we understand them, but I'm open to any suggestions from anybody as to where we go to now, because we seriously have got a problem and this is a very distressing occurrence."

Martin Garwood, a senior aquarist at Sydney Aquarium, says the number of attacks over the past year is "unusual".

"Adventure sports and surfing in remote locations has gotten a lot more popular over the last decade," he told ABC News 24.

"It is showing people are using the ocean in a broader sense than we ever used to and in much more remote locations.

"It is really more indicative how humans are using the ocean as opposed to the amount of sharks in this instance."

But he says there is no way to prove the deaths are not related to increasing shark numbers, as there is no reliable data on how many sharks are in the water.

"One of the best suggestions that's come out of this is the Fisheries Minister potentially reassessing whether great sharks belong on the protected species list," he said.

"That reassessment would involve an accurate population study specifically for Australia and the West Australian coast.

"Getting that up-to-date information would provide us all with whether or not there's more sharks and whether action needs to be taken."

Janita Enevoldsen from the Wilderness Society of Western Australia says taking the great white off the protected species list is not the right way to approach the problem.

"We need to really understand them and not resort to the neanderthal reaction of a hunt and kill," she said.

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Watch Duration: 5 minutes 30 seconds 5 m Acquarist Martin Garwood discusses the high number of shark attacks in WA

Fisheries officers tried unsuccessfully to find the animal on Saturday and resumed the search on Sunday.

If the shark is found, it will be killed.

While officials are looking for the shark, they say finding Mr Linden's remains are the first priority.

Witness Matt Holmes tried to help Mr Linden but says when he attempted to get close to his body, the shark attacked his jet-ski before taking Mr Linden's remains.

"I was towing my mate on the back of the jet-ski and just in front of us saw a guy get attacked by a shark," he told the ABC on Saturday.

"I just took my mate to the shore and went straight out and there was just blood everywhere and a massive, massive white shark circling the body.

"I reached to grab the body and the shark came at me on the jet-ski and tried to knock me off and I did another loop and when I came back to the body the shark took it."

David Peppercorn was surfing nearby and was told to get out of the water.

"We were in the water surfing and the jet-ski guy came up ... and the guy's basically said 'great white'," he said.

Daniel Hunt was also surfing at the beach.

"They were looking for him on the jet-ski, cruising up and down for 25 minutes afterwards. Apparently he's gone," he said.

Beaches in the area remain closed this morning.