NEW test results confirm that the virus that causes white spot disease in prawns has been identified in a new location near the Logan River.
As part of the ongoing surveillance program, more than 100 prawns taken from a site just south of the mouth of the Logan River have returned positive test results for the virus that causes white spot disease.
Of the more than 8000 wild-caught prawns since early December only seven positive results have been detected until now. Biosecurity Queensland is investigating the cause of the sudden spike in positive cases. All pathways are being investigated to identify the source.
Sampling and testing will continue to monitor the survival of the virus in the wild and to assess if it has established in the natural waterways. There remains a large number of samples currently undergoing testing at various laboratories. The results will continue to inform our approach to the current program, including our surveillance activities.
The national Aquatic Consultative Committee on Emergency Animal Disease has endorsed the current disease control program as the best way to manage this issue.
Work will continue to decontaminate the affected aquaculture farms in the area, and further discussions will take place with the individual farmers, industry and national authorities to identify strategies to allow prawn farming in the area to continue.
Te restrictions on the movement of crustaceans and worms from the Logan and Albert Rivers will remain in place while work is undertaken with the seafood and prawn farming industries on a plan for the next season.
Information on white spot disease
- What is white spot disease? White spot disease (WSD) is a highly contagious viral disease of decapod crustaceans including prawns, crabs, yabbies and lobsters. White spot disease is caused by white spot syndrome virus (WSSV).
- Where is white spot disease found? WSD is widespread throughout prawn farming regions in Asia and has become established in prawns farmed in the Americas where it has caused severe losses. Australia is one of the few countries in the world with a prawn farming industry that has remained free of WSD.
- How is white spot disease spread? The disease is primarily spread through the movement of infected animals or water. Birds feeding on infected animals can contribute to the spread of the disease.
- Can fish spread the virus? No. Fish are not carriers of the virus that causes WSD.
- How was the disease introduced to Queensland prawn farms? At this stage it is not known how the disease was introduced to this area. Biosecurity Queensland is investigating a number of possible pathways. However, our priority at this stage is to contain and eradicate the disease.
- What does white spot disease look like? Prawns with WSD may have a loose shell with numerous white spots (0.5-2mm in diameter) on the inside surface of the shell and a pink to red discolouration.
Other signs of WSD to look for include:
- Unusual mortality
- Prawns coming to the edge or water surface
- Prawns demonstrating unusual swimming patterns.
Prawns infected with WSD can be difficult to identify. They may develop visible white spots rapidly but it is important to note that these spots are not always present and that similar spots can be caused by other factors such as bacteria, high alkalinity and stress.
While other crustaceans such as crabs can be carriers of WSD, they may not display any visible signs and must not be moved from the movement control area. If you suspect white spot disease, you must report it to Biosecurity Queensland on 13 25 23 or the Emergency Animal Disease Watch Hotline on 1800 675 888.
Further information on white spot disease is available on the Department of Agriculture and Fisheries website.
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