The latest victim was 24-year-old surfer Ben Linden, who was bitten in half by a shark at the weekend.
Linden was killed by a 15ft-long great white as he surfed near Wedge Island, 100 miles north of Perth.
The lethal attack comes just three months after a 33-year-old diver was killed by a shark off the southwest coast. In September, a bodyboarder died from an attack near Bunker Bay; in October, a swimmer and a diver were killed around Cottesloe and Rottnest Island respectively.
An average of one person a year is killed by a shark in Australia.
Fisheries Minister Norman Moore said the unusually high number of attacks was “cause for great alarm” and suggested it was time to reassess the great white’s protected status.
A pair of divers were also attacked by a great white shark off the western coast of Australia at the weekend, but were able to fight it off with spears.
Jetskiier Matt Holmes was an eyewitness to the attack that killed Linden. He had been towing a friend nearby when he saw the shark strike.
“I just took my mate straight to the shore and went straight out and there was just blood everywhere and a massive, massive white shark circling the body. By the time I got out there half of him had been taken,” Holmes said.
“I tried to lean off the side and pull him on the back, but as I did that the shark came back and nudged the jet ski to try to knock me off.
“When I came back the second time, he took the rest of him.”
However, while the government is said to be reconsidering lifting the shark hunting ban, a senior aquarist at the Sydney Aquarium suggested that the spike in attacks could be more to do with the increasing popularity of watersports in remote locations, as opposed to a rise in great whites.
Conservationists have also expressed concern that electing to hunt down sharks will be a less effective solution than attempting to understand shark behaviour.
Moore said that more research was needed to understand why more attacks are occurring.
“We have allocated some AU$14m (£9.2m) … to get a better understanding of the great white sharks and the reasons why fatalities are occurring,” he said.
“I wonder if research might tell us that there are now much greater numbers of great whites than ever before.”