Spencer Gulf and West Coast charter fishermen believe the snapper fishing ban to come into effect on November 1 will be the hardest challenge their businesses have had to face.
Daniel Gilbertson has been a charter fisherman in the Coffin Bay area for three years and said while he was lucky snapper were not his target fish on tours, others relied on the species to attract customers and business.
"Those guys up there (in the Spencer Gulf), their whole charter business is built around that snapper so those guys are basically being told they can't go to work as of November 1," he said.
He also said the snapper ban would have a big residual effect on local communities.
"Obviously it doesn't just affect the fishing, tours aside we're looking at tackle outlets, caravan parks, the fuel, all the way down to bait supply so it'll have a huge flow on effect and the dollars spent in the towns," he said.
"People will often stay here for two nights and so you're looking at accommodation, their food, they buy ice...every snapper they catch is probably worth $500 to the economy."
Ash Smith, a charter operator in the gulf out of Arno Bay, said he did not know how he would "keep his head above water" during and after the ban.
"It's okay for the professional fishermen, it's four summers, they can go fish for a few other species," he said.
"As soon as the season opens again, they catch snapper, they've got a product they can sell...even if it does open again in 2023, it's going to take three or four years to get back to where we are."
Mr Smith said the ban was already affecting his business because of the confusion over when it would begin.
"They said they were going to start it in the start of October...I've had guys who had booked flights from interstate that have gotten nervous and either cancelled or didn't book," said Mr Smith.
"It's killed me even when I can fish still."
Mr Gilbertson said if he accidentally caught a snapper, he would be putting it back in the water to die.
"Because we're bringing them out of 50 metres, which is the depth we fish out here, they won't survive... as they come up it's like getting the bends," he said.
He said the charter industry took catch limit reductions off their own backs last year and now it would be difficult to pay their bills and mortgages as well as maintain equipment and licence fees.
He said the government should listen to the anecdotal evidence, including the amount of snapper in the water and that many elements such as species shifting and changes to breeding spots had flawed the government's science.