Drum lines will not be deployed off WA beaches this summer after the state's Environmental Protection Authority advised against extending the Government's controversial catch and kill shark policy.
The regulator's chairman, Paul Vogel, said the available information and evidence did not provide the organisation with a high level of confidence.
Following a spate of fatal shark attacks in the state, in January the WA Government introduced a 13-week trial where baited drum lines were set off Perth and South West beaches.
During the trial, which cost the Government $1.3 million, 68 sharks were caught and shot, although none of them were great white sharks.
The catch-and-kill policy was widely opposed with hundreds attending community rallies and international marine scientists calling for it to be scrapped.
Premier Colin Barnett said the recommendation meant drum lines would not be in place off the WA coast this summer.
Dr Vogel said the EPA had been tasked with assessing the environmental impact of the strategy, not public safety.
"There remains a high degree of scientific uncertainty about the impacts on the viability of the south-western white shark population," he said.
"At this stage, the available information and evidence does not provide the EPA with a high level of confidence. In view of these uncertainties, the EPA has adopted a cautious approach by recommending against the proposal.
"The EPA can only make a judgment on the impact on the environment. The minister, in making his final decision, may take other matters into consideration."
WA Premier 'disappointed' with decision
The EPA assessed the program as a Public Environmental Review, the highest level of environmental impact assessment.
The proposal attracted 6,751 public submissions and two petitions with about 25,000 signatures.
The EPA's latest decision stands in stark contrast to its initial ruling on the program's trial in March, where it refused to assess the trial on the basis it posed a "negligible" risk to the species.
Mr Barnett said he was disappointed but would accept the EPA's decision.
"I find it extraordinary... that the catching of sharks could be prohibited in WA, but allowed in New South Wales," he said.
Mr Barnett said it was unlikely the State Government would appeal the EPA's decision.
"That means that it will not be possible to have drum lines over this summer," he said.
He said while he was confident Perth beaches were as safe as they could be, he remained concerned about SouthWest beaches, where sharks often lingered for long periods of time.
"Regrettably, I cannot say that the South West has the degree of safety that Perth beaches do have and that 's the real issue that we've got to face now," he said.
The Department of Premier and Cabinet's own review had already recommended the program be extended for the next three summers, but could not determine whether the policy was effective at keeping swimmers safe.
It found that while it was "likely" to have reduced the risk of attack, the "trial has been short and shark attacks generally too infrequent to have generated substantial quantitative data to measure the reduction in risk".
In a statement, a spokesman for Federal Enviroment Minister Greg Hunt said the minister would look "very carefully" at the EPA's assessment report, the advice of the department, and the thousands of public submissions received.
"The Commonwealth decision is based on nationally protected matters, including impacts on listed threatened species and communities and listed migratory species," he said.
Meanwhile the Wilderness Society had welcomed the EPA's announcement.
The society's WA director, Jenita Enevoldsen, said it was a milestone decision for the state.
"Typically these days, when there is uncertainty about impacts, the EPA and other government agencies have taken the view that projects should be approved, but managed to address unforseen or unintended impacts," she said.
"This is ... one which again highlights the need for the Government, as a matter of urgency, to fulfil its election commitment and pass new Biodiversity Conservation legislation to replace the 1950 Wildlife Conservation Act in WA."
WA Greens MP Lyn MacLaren described the EPA's recommendation as "common sense".
No white sharks caught in trial
During the three-month trial of the policy, tiger, great white and bull sharks more than three metres long were killed if caught on baited hooks set off Perth and South West beaches.
The state had been hoping to expand the program for another three years, where it would set up to 60 baited drum lines across Perth and the South West from November to April each year.
The Government has claimed the shark cull was a success but there has been community opposition to the policy, with a number of large public rallies being held.
Earlier this year environmental campaign group Sea Shepherd failed to get a Supreme Court order to stop the cull.
Initially, baited drum lines were to be set and monitored off Perth beaches by private contractors.
The Government later decided to use Department of Fisheries staff instead, citing security concerns because of opposition to the policy.