by Steve Lague

Fishermen are again being urged not to use prawns meant for human consumption as bait following the discovery of white spot disease in the wild.

Last month we warned of an outbreak of the disease, which is deadly for crustaceans but harmless for humans, in several prawn farms in Queensland.

New test have now revealed that the virus that causes white spot disease has been identified near the Logan River, in South-East Queensland, which raises the issue of the extent of the virus in the wild.

Chief Biosecurity Officer for Queensland Department of Agriculture and Fisheries, Dr Jim Thompson said that as part of a comprehensive and ongoing surveillance program, more than 100 prawns taken from a site just south of the mouth of the Logan River had returned positive test results for the virus.

“We have tested more than 8000 wild caught prawns since early December with almost no positive results until now,” Dr Thompson said.

“What has caused this sudden spike in positive cases at a new location is unknown at this stage. All avenues are being investigated to identify the source.

white spot disease

“We will continue sampling and testing to monitor the survival of the virus in the wild and to assess if it has established in the natural waterways.”

Dr Thomas said the current testing programme was the best way to manage the issue according to experts in the field.  He said the virus usually needed high densities of prawns to take hold and spread.

“This is not generally the situation in the wild where populations of crustaceans are in much lower densities than in an aquaculture environment, so it’s possible the presence of the virus may reduce over time,” he said.

“While we will continue our current program of decontaminating the affected aquaculture farms in the area, there will be ongoing discussions with the individual farmers, industry and national authorities to identify strategies to allow prawn farming in the area to continue.

“In the meantime I would remind anyone going fishing in the area that they should source bait from bait shops and not to use store-bought prawns which are only intended for human consumption.”

While the disease is located in Queensland, fishermen nationally are being urged to take care and only use prawn bait sourced from bait shops. If you think your prawns could be infected with the white spot disease, stop using them and report it to your local Fisheries Department.

For more information about WSD can be found here.