White Spot Disease

Published: 29 June 2021 Updated: 13 May 2024

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White spot disease (WSD) is an internationally notifiable disease of crustaceans caused by white spot syndrome virus (WSSV). WSD causes up to 100 per cent mortality on prawn farms throughout Asia, the Americas, and the Middle East. WSSV infects a wide range of decapod crustaceans and is considered exotic to Australia.

On 22 November 2016, a WSSV incursion was first reported in Black Tiger Prawns (Penaeus monodon) grown on a prawn farm taking water from the Logan River, south east Queensland (SEQ). The exotic virus proved to be highly contagious and subsequently spread to infect all operational prawn farms in the area by February 2017. These farms lost all stocked prawns during a disinfection program undertaken to contain and eradicate the virus. Surveillance conducted by Biosecurity Queensland during March 2017 also detected WSSV in wild commercially caught prawns and crabs in the Logan River and north-western parts of Moreton Bay (over 70 kilometres north of the Logan River). The most likely pathway for introduction of WSSV into Moreton Bay is widely considered to be through using imported uncooked prawns infected with WSSV as bait or burley by recreational fishers.

In response to the incursion, in 2017 a white spot biosecurity control zone was established restricting the movements of uncooked crustacean products out of Moreton Bay. This significantly impacted commercial fishing industries in Moreton Bay supplying bait prawns and bloodworms. In an attempt to eradicate WSSV, all prawn farms on the Logan River were required to cease production for the 2017-18 growing season.

WSSV was detected north west of Moreton Bay in the late summer of 2018 and most recently in March 2020. In April 2020 WSD was also recorded on prawn farms adjacent to the Logan River. In August 2022 WSSV was detected in a bio-secure prawn farm hatchery in Northern NSW. WSSV was detected in Black Tiger Prawn farms on the Clarence River in early 2023. The outbreak in NSW has been assessed as not being linked to the Qld outbreak.

In October 2017, the FRDC ran a white spot disease research and development needs workshop - see report.

In response to the WSD outbreak, FRDC implemented the following projects to support the prawn farming and wild catch sector and provide clear direction towards planning for future recovery for affected farms and fisheries. The projects aimed to improve farm biosecurity, protect the biosecurity of areas within the control zone and develop alternative markets for prawns caught or farmed in the control zone.

In response to the WSD outbreak, FRDC implemented projects to support the prawn farming and wildcatch sector and provide clear direction towards planning for future recovery for affected farms and fisheries.

In addition to this research, a consumer market research study was initiated to provide an estimate of the likely ‘reach’ and ’impact’ of this issue. The research was conducted with a representative sample of the Australian population aged 18 years and over.

Future research needs

It is likely the FRDC will need to support a range of WSD R&D projects in future as immediate, medium and longer-term priorities are identified through current project activities and ongoing consultation between industry, national and international aquatic disease experts and government R&D and biosecurity agencies.

Food safety and information for consumers

White spot disease does not pose a threat to human health or food safety.

Common questions

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.
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.
What does white spot disease look like?
Prawns with WSD may have a loose shell with numerous white spots (0.5-2.0 millimetres in diameter) on the inside surface of the shell and a pink to red discolouration.
For more information about how to identify white spot visit https://qsia.com.au/wp-content/uploads/2018/01/Attachment-40.pdf
How to report white spot disease
It is crucial that all aquaculture operators, commercial and recreational fishers and other waterway users report unusual signs in prawns (including bait) and other crustaceans.
Early detection provides a better chance of being able to contain and eradicate this serious disease.

If you see crustaceans that you suspect have the disease it is important to take note of the location and time and report this information immediately to Biosecurity Queensland on 13 25 23.

Alternatively phone the Emergency Animal Disease Watch Hotline on 1800 675 888 from anywhere in Australia.