A State Government ban on using offal and blood to catch sharks off popular swimming beaches has not begun almost a year after it was promised.
Department of Fisheries director-general Stuart Smith has confirmed the agency is having trouble framing the ban because it is worried recreational fishers could fall foul of the ban.
Under the proposal, announced by Fisheries Minister Norman Moore in November after three fatal shark attacks in two months, a ban on the "disposal of offal and blood" was to be extended.
Currently, the ban applies only to a small area off Cottesloe but the Government wanted it widened to include other popular swimming beaches in Perth and regional centres.
The failure to implement the ban means fishers hunting for sharks are free to use or dispose of blood and offal in practically all waters off populated areas.
A Government plan to increase the maximum fine for the illegal disposal of the substances from $2000 to $10,000 is also in limbo.
Mr Smith said work on the ban was progressing but the department was finding it "challenging" to define what would constitute offal in order to avoid "unintended consequences".
"How do you define it such that someone fishing for tailor or herring or something like that isn't seen as disposing of offal at sea because they're obviously not trying to take a shark," he said.
"It's probably going to come down to what the purpose of it is, which is all well and good but that then poses a prosecution difficulty.
"We then have to prove that the purpose of the disposing of the offal was to catch a shark as opposed to other types of fish."
The admission came as acoustic receivers off Perth's northern beaches recorded a flurry of activity from tagged great white sharks late last week and further confirmed detections yesterday.