Mud crabbers in Queensland's Moreton Bay say tough biosecurity measures to control a prawn disease outbreak have resulted in their incomes being halved.

In March, the State Government announced a ban on the movement of crustaceans caught between Caloundra and northern New South Wales.

The ban also prevents them from selling their catch beyond south-east Queensland as authorities attempt to stop the spread of white spot disease, which has wiped out seven prawn farms on the Logan River.

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Listen Duration: 5 minutes 1 second 5 m Marty McCarthy reports on the impact of white spot disease on Logan River mud crab catchers ( Marty McCarthy ) Download 4.6 MB

Sean Lothian, a commercial crabber based on the Logan River, said he is struggling to make a profit while the movement restrictions are in place.

"In my eyes, the white spot they have claimed to have found here has taken its toll on us commercial guys and recreational guys," Mr Lothian said.

"It has changed dramatically because for us, we used to send crabs to Sydney Fish Markets weekly but now we can't send down south because of the new movement zone.

"We are forced to sell at a lesser price here in Brisbane and it is making life hard for us."

Mr Lothian said this time last year he was selling mud crabs in Sydney for $40 a kilogram, but is now only getting around $20 in Brisbane.

"It is extremely difficult to lose those markets after years of selling to the guys down there, where we have a good name and market," he said.

"It is a huge kick in the guts.

"They [authorities] could lift the ban tomorrow and let us send stock back there, but are the fellas down there going to buy it? Are they going to be scared of the white spot?"

Commercial mud crabber Sean Lothian says the white spot disease outbreak has hurt his business ( ABC Rural: Marty McCarthy )

White spot is not a risk to human health but it is a threat to other prawn farming regions if it spreads from live or fresh product to farms in New South Wales or north Queensland.

The movement ban announced by the Queensland Government in March affects prawns, crabs, yabbies and even worms, although seafood can still be sold interstate provided it is cooked first.

However, Mr Lothian said there was no market for cooked mud crabs as consumers preferred fresh product.

"People prefer them fresh and alive rather than cooked. The cooked market for us is a waste of time and we may as well pack up," he said.

Mr Lothian is a second generation crab catcher and hoped to pass the business on to his children.

"It supports my wife and three kids and I'm finding it hard at the moment, but I am getting there," he said.

"We need to survive but for us to survive, we have to be able to catch and sell crabs.

"If we can't sell crabs, what are we going to do?"