A group of fishermen aim to tap Asia's lucrative abalone market by establishing Australia's first wild farm for the mollusc off Augusta.
But opponents claim it will threaten their livelihoods.
Ocean Grown Abalone has been running a pilot project to "ranch" green lip abalone at a 40ha site in Flinders Bay since 2011 but wants to treble the farm's size to boost production and make it commercially viable.
The group, which is spearheaded by former abalone diver Brad Adams and counts among its backers Ian Ricciardi from Rottnest Island Scallops, has applied to the Fisheries Department for approval.
It is now set to go to the market seeking $8 million from investors for an overall plan expected to cost $16 million.
Under the proposal, juvenile abalone would be bred in hatcheries before being planted on artificial reefs in Flinders Bay and left to grow for two to three years until they could be harvested.
Mr Adams said that unlike a wild fishery, stock from the farm could be harvested at smaller sizes, production was uncapped and there were no seasonal closures.
But Abalone Association of WA executive director Ian Taylor warned the project should not be allowed to go ahead because it posed an unacceptable risk of bringing disease into WA's valuable wild stocks.
Arguing the "vast majority" of abalone licence holders were against the plans, Mr Taylor insisted their opposition was not fuelled by fears of increased competition but rather threats to bio-security.
He cited recent outbreaks of disease among wild abalone stocks in Victoria and Tasmania, saying they had stemmed from aquaculture farms and had devastated the fisheries, forcing operators to sue taxpayers for millions.
"The experience elsewhere in intensive farming, whether it be aquaculture or farming chooks, is that in the end you end up with a disease problem," Mr Taylor said.
Mr Adams said the trial project had proved abalone could be farmed successfully in Flinders Bay without unacceptably risking wild stocks. He said this was supported by researchers from Curtin University.
Ahead of expected decisions by the department and Fisheries Minister Troy Buswell in coming months, he said the proposal was looming as an acid test for WA's fledgling aquaculture industry.
At stake was millions of dollars in potential trade with China, where green lip abalone is considered a delicacy.
Mr Adams said rejecting the project would also be a blow to the Augusta economy, which has long struggled compared with neighbouring Margaret River.
"Aquaculture in WA would be set back three years if they (the Fisheries Department and Fisheries Minister) knocked back the application," Mr Adams said.