The Logan River has been closed to fishing for prawns and crabs as Biosecurity Queensland tries to figure out how an outbreak of white spot disease in prawns has occurred.
The disease threatens the Australian prawn farming industry which produces more than 5000 tonnes annually, with a farm gate value of $87.7 million.
The closure is likely to impact the plans of fishers in the area over Christmas although authorities say there is no human health impact.
Chief biosecurity officer Jim Thompson said tests had confirmed the virus in wild prawns from the river.
“We are moving quickly to reduce the chance of the virus spreading any further through locally-caught wild prawns, crabs or worms,” he said.
“Any movement of green, uncooked crustaceans taken from this area would pose a real risk for moving the virus beyond the Logan River.”
Biosecurity scientists have been destocking and decontaminate ponds at two aquaculture farms south of Brisbane after an outbreak of the disease.
Australia has previously been WSD free and this is the first confirmed case in aquaculture.
The federal Agriculture Department says the disease infects only crustaceans and is not related to the parasitic disease also known as white spot in fish.
It says the disease has mainly been a problem in farmed prawns, rather than wild animals.
Dr Thompson said surveillance had started on prawn farms and in nearby waterways to determine possible sources of infection.
Queensland Boating and Fishing Patrol has asked recreational fishers to report unusual signs in prawns and crabs caught in the area.
Prawns with WSD may have a loose shell with numerous white spots (0.5-2.0 mm in diameter) on the inside surface of the shell and a pink to red discolouration.
The Logan River is now closed from the Jabiru and Luscombe Weirs in the west to the mouth of the river in the east.
The movement control order restricts any movement of crabs, worms and prawns out of the defined area. Fin fishing and boating is still allowed.
Crustaceans are crabs, lobsters, crayfish, shrimp, krill, woodlice and barnacles.