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Fish Disease: Abalone Viral Ganglioneuritis

Health Sustainability

With outbreaks of Abalone Viral Ganglioneuritis (AVG) in Tasmania, the New South Wales government (Australia) has implemented a temporary suspension on imports of live abalone from Tasmania. looks at what the disease is and how the disease is being managed in Australia.

Lucy Towers thumbnail

What is Abalone viral ganglioneuritis?

Abalone Viral Ganglioneuritis, or AVG, is a viral disease that affects the nervous system of abalone and results in curling of the foot, swelling of the mouth, weakness and death. AVG has not been detected in NSW wild abalone stocks.

Can AVG affect humans?

There is no evidence that AVG has any effect on human health.

Where is AVG known to occur?

AVG was first detected in Australia in 2005 in two Victorian abalone processors, and subsequently in wild Victorian abalone stocks. It was later confirmed in Tasmania in 2008 in both wild stocks and at seafood processing facilities. Tasmania has reported further outbreaks of AVG in 2010 and 2011.

Internationally, a similar abalone virus is reported in abalone in Chinese Taipei.

What is the NSW government doing to protect NSW abalone from AVG?

Since 2007, the NSW Government has banned the use of abalone viscera, or gut, as bait in NSW. The use of abalone gut as bait has a high risk of introducing AVG into NSW populations of abalone, which would have severe and irreversible impacts on NSW abalone fishery. The closure was implemented to prevent the spread of AVG from the use of gut as recreational or commercial fishing bait. In December 2007 NSW DPI published and distributed a Standard Operating Procedure for decontamination for commercial abalone divers in NSW to help protect abalone stocks in NSW from AVG.

Has AVG been detected in NSW?

AVG is not known to occur in wild abalone in NSW. However, AVG was confirmed in abalone at a NSW seafood retailer’s holding tank in late November 2011. The stock that tested positive to AVG had been received from a seafood processor in Tasmania that had experienced a recent AVG outbreak.

How did the NSW government respond to the confirmation of AVG in NSW (from stock imported from Tasmania)?

The NSW Government has responded by placing a temporary ban on the importation of live abalone from Tasmania. NSW DPI is conducting investigations to determine whether other NSW premises may be infected with AVG, and is requiring all affected stock to be processed or disposed of appropriately. Abalone tanks within infected premises are required to be cleaned and disinfected before they can be restocked with live abalone.

Why hasn’t the NSW government restricted movements from Tasmania before now?

AVG is an emerging disease in Victoria and Tasmania. Prior to 2005 it was unknown in Australia. Both the Victorian and Tasmanian Governments have been investigating the emergence of this disease since it was first detected in each state, and management controls have been developed (including fishing closures and quarantine procedures) that minimise risks when an outbreak is detected. Research on AVG in Australia has resulted in the development of new diagnostic tools, which have helped improve our understanding of this disease. Research is still underway, and our understanding of AVG continues to improve.

Up until 23 November 2011, AVG had never before been detected or suspected to have been imported into NSW, and it was understood that the protocols in place in Tasmania and Victoria were working.

Does AVG affect any other fish or seafood product?

No, AVG is known to only affect greenlip and blacklip abalone and their hybrids.

How does the virus spread?

AVG can be transferred between abalone via water and infected abalone, including abalone mucus. NSW has banned importation of Tasmanian abalone to prevent the virus being introduced to NSW abalone.

Does human activity spread the virus?

Use of abalone gut has been banned in NSW to reduce the risks of this activity spreading the virus into the NSW abalone fishery. Virus particles can attach to commercial or recreational divers’ gloves and wetsuits which can be moved from one location to another, thereby spreading the virus. The Victorian abalone industry has implemented closures and decontamination protocols to prevent the virus from spreading from known AVG locations through human activity.

What can I do to help?

The community is encouraged to report any observations of sick, dying or dead abalone to the NSW Fishers Watch hotline on 1800 043 536.

January 2012