About White Spot
White Spot spread through Asian prawn farming regions rapidly in the 1990s and later was reported from prawn farms in the Americas, where it caused widespread production losses.
In December 2016 White Spot was detected in farmed prawns in south-east Queensland.
In August 2022 White Spot was detected in an enclosed facility at a prawn farm in northern NSW. The department acted quickly to implement formal biosecurity measures and worked closely with the farm to contain the detection within the facility. All prawns within the facility were destroyed and the facility was decontaminated. The department undertook surveillance of wild prawns in the estuarine area and offshore from the facility with no evidence of White Spot found.
In early 2023, White Spot was detected at three prawn farms in northern NSW. Further surveillance of wild prawns under a NSW Long Term surveillance plan was underway by the department in the Clarence River area when the most recent detection near Evans Head in May 2024 occurred as part of routine surveillance.
What are the characteristics of White Spot?
Signs of White Spot in aquaculture within tanks and ponds include:
- rapid onset of mass mortality (80% or more) in farmed penaeid prawns during the grow out period
- lethargy
- cessation of feeding
- aggregations of moribund prawns near the water surface at the edge of the rearing pond or tank
Prawns may display:
- a loose carapace
- high degrees of colour variation, with a predominance of darkened (red-brown or pink) body surface and appendages
- white calcium deposits embedded in the shell, causing white spots 0.5 to 3.0 mm in diameter.
Please note, as with any aquatic disease, diagnosis cannot be made without appropriate laboratory testing. For information on how to submit samples for diagnosis contact the Aquatic Biosecurity team on the Emergency Animal Disease Hotline, 1800 675 888, or by email aquatic.biosecurity@dpi.nsw.gov.au.
More information on the characteristics of White Spot:
What you should do if you suspect a prawn has White Spot?
Please report any unusual mortalities or suspicions of White Spot to the Emergency Animal Disease Hotline 1800 675 888 or email aquatic.biosecurity@dpi.nsw.gov.au.
Consumer safety
Prawns are safe to eat. White Spot does NOT pose any threat to human health or food safety.
What you can do to help prevent the spread of White Spot
White Spot is declared as Prohibited Matter under Schedule 2 of the Biosecurity Act 2015. There is a duty to report the presence or suspected presence of White Spot at any place to the department, and strictly prohibits any dealings with this biosecurity matter or associated carriers.
Information for recreational fishers and members of the public
- Never use prawns intended for human consumption as bait. Using imported raw prawns as bait may introduce serious diseases into our waterways
- When fishing, always source your bait from a trusted bait supplier, such as a tackle shop, or catch your own#
- It is illegal to bring bait caught in south-east Queensland to NSW, source your bait from a trusted supplier local to the area you intend to fish
- Dispose of your prawn waste (heads or shells) in general waste, never into our waterways
- Make ‘clean’ part of your routine (PDF, 385.23 KB), wash your vehicles and gear between waterways
- If you catch your own bait, use it only in the water from where you caught it
- If you are a recreational fisher, please refer to important information for recreational fishers - use of prawns as bait
# Refer to NSW Fishing rules and regulations
Information for prawn farmers
- Follow your permit conditions, including those relating to biosecurity
- report any unusual mortalities or suspicions of White Spot to the Emergency Animal Disease Hotline on 1800 675 888 or a local Fisheries Officer as soon as possible, and within 24 hours
- Ensure your Biosecurity Plan is up-to-date based on current biosecurity requirements and guidelines and being implemented to minimise the risks of aquatic disease entering your property
- Use separate equipment where practical. If unable, please decontaminate minimise unnecessary visitors to production areas of your farm and find out where delivery trucks and other visitors have previously visited before accepting them on site
- Primefact - NSW Prawn Farms: Enhanced biosecurity measures
Information for seafood processors and bait suppliers
- Be aware of the control order currently in place on uncooked prawns, decapod crustaceans (including lobsters, crabs, slipper lobsters, Moreton Bay bugs) and polychaete worms (including beach worms) originating from within the Clarence River Control Area and an area between Caloundra and Tweed Heads in south-east Queensland.
- Ensure that you are not buying or selling uncooked prawns, decapod crustaceans, or polychaete worms (for bait or human consumption) in NSW that have been sourced from within the Clarence River Control Area or the affected area in south-east Queensland, unless they have been treated in accordance with the control order.
- Movement (or transiting through) control areas into NSW (or to other areas of NSW) of uncooked decapod crustaceans destined for human consumption only, not bait, can only occur if they have originated from outside the control areas, the packaging remains secure, the grower and packer details are clearly displayed and they are transported directly to a point of sale in NSW for human consumption.
- Note: there are no movement restrictions on cooked decapod crustaceans that are securely packaged and transported directly to a point of sale in NSW.
Information for commercial fishers
- The Control Order prohibits the movement into NSW of uncooked prawns, decapod crustaceans, and polychaete worms (marine worms) originating from both
- the Clarence River Control Zone, and
- the area between Caloundra and Tweed Heads in south east Queensland .
- Certain high value decapod crustaceans, including lobsters, mud crabs, blue swimmer crabs, spanner crabs, and slipper lobsters (Moreton Bay bugs), are classified as excluded carriers and may be moved out of the control zone uncooked subject to these conditions:
- It is being moved for human consumption
- It is cooked by the end consumer as soon as possible after arriving at its destination, and
- If it is alive, it is not placed in waters to which the Fisheries Management Act 1994 applies.
- You are required to ensure that:
- Any water used for the transport of the excluded carrier is disposed of through a public sewer
- Any waste produced for the transport of the excluded carrier is disposed of at a waste depot.
- The transportation of the excluded carrier is accompanied by documents which state the date the excluded carrier was captured or harvested and the location in the Control Zone where it was captured or harvested.
- Fittings used in the control areas in connection with cultivation or commercial catch of live or dead decapod crustaceans or polychaete worms are also prohibited from entry into NSW unless they are cleaned in accordance with a protocol approved by the NSW Chief Veterinary Officer.
- If trading interstate, check with the appropriate state for their restrictions as they differ from state to state.
White Spot and the Clarence River
White Spot was detected in three northern NSW prawn farms in early 2023 adjacent to the Clarence River. These detections were confirmed by the department and Australian Centre for Disease Preparedness (ACDP).
On-farm White Spot eradication activities were finalised in early October 2023.
Biosecurity measures within the Clarence River Control Zone continue to be managed by the department under a Biosecurity Control Order in force until 8 June 2025.
This control order restricts the movement of raw, uncooked decapod crustaceans, including crabs, lobsters, crayfish, shrimp and prawns, and polychaete or beach worms out of the Clarence River Control Zone.
The control order also requires enhanced biosecurity measures on NSW prawn farms to boost risk management, including:
- traceability and record keeping
- broodstock and post-larvae testing requirements
- appropriate feed usage and
- stock security - screening and pond management
Interstate Trade restrictions
Other states have imposed different trade restrictions on uncooked prawns, decapod crustaceans and polychaete worms. Please check the relevant fisheries website - see www.outbreak.gov.au for more information.
Report any signs of unusual mortality or other suspicions of White Spot
If you suspect White Spot, call the 24-hour Emergency Animal Disease Hotline: 1800 675 888
FAQs
What is White Spot?
White Spot affects decapod crustaceans including prawns, crabs and lobsters. It is highly contagious to prawns and other farmed crustaceans and can cause high rates of mortality in affected prawn stock. Wild crustaceans can be carriers of White Spot; however they are rarely affected.
Where was the most recent detection?
The department confirmed a second detection of white spot syndrome virus (WSSV) in wild-caught school prawns (Metapenaeus macleayi) in northern NSW. Prawn samples collected from the Richmond River offshore area were tested at Elizabeth Macarthur Agriculture Institute (EMAI) and returned a positive result for White Spot.
On Saturday 25 May the positive result from EMAI was confirmed by the Australian Centre for Disease Preparedness.
This detection comes after WSSV was found in prawns caught outside the mouth of the Evans River NSW on 8 May 2024. This is the first time white spot has been detected in ocean waters of NSW.
What is the Biosecurity Control Zone?
A Biosecurity Control Order which initially covered the positive detection near the Evans River has been amended to take in the location of the second detection near the Richmond River, confirmed on 25 May 2024. The Control Zone encompasses the waters of the Richmond and Evans Rivers and adjacent ocean waters 10km north of the Richmond River mouth to 10km south of the Evans River mouth in a Control Zone
The control zone is directed at reducing the spread of the WSSV from the zone. This control zone places restrictions on the movement of green (uncooked) school and king prawns and other decapod crustaceans (excluding mud, blue swimmer, three spot and spanner crabs, lobsters, and bugs), and beach and other polychaete worms out of the area to minimise risks of spread to other areas in NSW and Australia.
You can find out more here.
How was White Spot introduced to NSW?
White spot was detected in NSW in an enclosed hatchery facility in August 2022, and subject to response actions with an intent to eradicate from the premises.
In February 2023, NSW confirmed white spot as the cause of mortality in prawn farms adjacent to the Clarence River.
Surveillance and epidemiological investigation after the 2022/23 events was unable to confirm the source of white spot into NSW. Further surveillance of wild populations is ongoing to define the limits of WSSV in the wild.
Samples from the Evans River detection were analysed via whole genome sequencing at the CSIRO Australian Centre for Disease Preparedness, confirming on 9 May the strain found off Evans River is the same as the strain that was associated with the prawn farm white spot disease response in 2023.What is the Government doing in response to this new White spot detection?
Epidemiologists, biosecurity, fisheries and aquatic health specialists from the department are working to determine what additional investigation and surveillance is required to inform the most appropriate next steps.
The Government is in regular contact with affected stakeholders and will continue to communicate with them to determine what assistance they require moving forward and advise of available supports.
The department continues to work closely with industry and with other states, territories and the Australian Government to help minimise the risk of White Spot on our commercial prawn fishing and prawn aquaculture industries.
Is it still safe to eat prawns?
Yes. White Spot does not pose any human health or food safety concerns.
Does cooking inactivate White Spot?
Yes. Cooking prawns in boiling water for a minimum of three-and-a-half and four-and-a-half minutes, depending on the size, will inactivate White Spot.
Does freezing inactivate White Spot?
No. Freezing does not inactivate White Spot.
Can fish spread White Spot?
No. White spot of prawns and other decapod crustacea has a different cause to the "white spot" that fishkeepers may be familiar with. White spot of crustacea does not affected finfish, and white spot of finfish does not affect crustacea.
What does it mean for the future of prawn wild stocks?
Wild crustaceans can be carriers of White Spot, however they are rarely affected.
The impacts from White Spot on prawns in the wild is difficult to evaluate as there is little evidence about the effects of White Spot on wild populations in overseas countries, where it is known to occur and is considered endemic.
The recent detections of White Spot were in wild-caught school prawns (Metapenaeus macleayi). These prawns were not showing of illness at the time of detection.
There have been no detections of white spot in any other decapod or prawn species in NSW (including Eastern King Prawns).
What are the consequences for the industry?
White Spot causes major impacts on the prawn farming and prawn fishing communities and associated industries on which many people rely to make a living.
To minimise the further risk of spread and impact of white spot, formal control measures are required in areas where white spot is detected. The department will continue to support industry in exploring other alternative options, as well as to identify reasonable and appropriate supports following longer term management approaches being implemented
What should people look for?
Wild prawns in most cases do not display any signs of White Spot.
Signs of White Spot in farmed prawns include:
- rapid onset of mass mortality (80% or more) in farmed penaeid prawns during the grow out period
- lethargy
- cessation of feeding
- aggregations of moribund prawns near the water surface at the edge of the rearing pond or tank
Prawns may display:
- a loose carapace
- high degrees of colour variation, with a predominance of darkened (red-brown or pink) body surface and appendages
- white calcium deposits embedded in the shell, causing white spots 0.5 – 3.0 mm in diameter
Note: prawns can appear to have visible white spots for various other reasons, including from being frozen and in most cases, are not due to White Spot.
Who should people contact if they suspect a prawn has White Spot?
Biosecurity is a shared responsibility and everybody plays a part in safeguarding Australia’s and NSW’s biosecurity, protecting our economy, environment and community and our reputation as a clean and safe producer of healthy seafood.
Any questions about or suspicions of White Spot should be directed to the Emergency Animal Disease 24-hour Hotline on 1800 675 888.
Further information about White Spot can be found at www.dpi.NSW.gov.au/white-spot
What does the new detection mean for the Clarence River Control Order?
The Clarence River Control Zone remains in place. With the current information available, the Evans and Richmond River detections are being treated as new incidents and separate to Clarence River.
You can access the Clarence River Control Order here.
What can recreational fishers do to help stop the spread of White Spot?
Recreational fishers do their part by:
- Never using prawns meant for human consumption as bait.
- Sourcing their bait from a quality, trusted supplier or collect their own from where you intend to fish
- Disposing of their waste (heads or shells) in the bin, never in our waterways
- Cleaning their boat, trailer, rods and other equipment before using them in another location.
More information
- Updates to industry:
- Make ‘clean’ part of your routine (PDF, 385.23 KB) – Fact sheet
- Important information for rec fishers – use of prawns as bait
- Biosecurity (White Spot – Clarence River) Control Order (No.2) 2023
- Plain English Guide for the Biosecurity (White Spot Disease – Clarence River) Control Order 2023
- Primefact - NSW Prawn Farms: Enhanced biosecurity measures
- Long-term White Spot surveillance plan - Fact sheet
- Group permit for surveillance activities in Clarence River to June 2025