A Dunsborough scientist says recent shark sightings suggest at least one Great White is loitering in Geographe Bay.
Writing in the Edith Cowan University magazine published in November, ECU science lecturer Rob Holt said surfers felt unsafe after the State Government decided not to proceed with its drum line program.
"We talk about shark attacks being mistaken identity of surfers for seals, but perhaps one or two of these intelligent predators have learned there's an opportunity for easy pickings," he wrote.
"Anecdotal information, confirmed by recent sightings, suggests at least one mature Great White has curtailed its migration to remain within Geographe Bay."
Mr Holt told the _Times _ the information came from "reliable sources" within the Capes surfing and fishing communities.
He was speaking before a 17-year-old boy died after a shark attack at Cheynes Beach in Albany on Monday.
"We have a huge seal colony at the end of the cape that's a big draw for the sharks," he said.
"When you have those food sources available the sharks will be there at those locations."
A long-term surfer and expert in oceanography and meteorology, Mr Holt said he no longer surfed at Rocky Point for fear of sharks.
"There are seals there. There have been sightings, but no fatalities," he said.
"Three or four years ago I saw a Great White in a wave - I got out of the water very quickly."
Mr Holt urged the Department of Fisheries to consider a more precise version of the drum line program and said more Great White research was essential.
A spokeswoman for the Premier said the Government had put in place a comprehensive suite of shark mitigation measures, including the deployment of temporary drum lines for a shark or sharks that present an imminent threat to water users.
Greens MLC Lynn MacLaren attacked the Government's imminent threat shark policy, claiming it was largely based on Jaws movie mythology.
"The Premier continues to talk about 'rogue sharks' that 'lurk' off our beaches, despite a huge amount of world-class research by the Department of Fisheries that has shown that white sharks … do not show strong affiliations to any area or patterns of movement," she said.
Ms MacLaren criticised the Premier for vowing to introduce a new policy for killing sharks this summer, without environmental assessment.