White Spot Disease (WSD), also known as infection with White Spot Syndrome Virus (WSSV), is a highly contagious viral disease of prawns that causes high rates of mortality in affected stock. Other crustaceans can be carriers of the virus, but they are rarely impacted by the disease. WSD poses no threat to human health or food safety.
WSD spread through Asian prawn farming regions rapidly in the 1990’s and also became established in in farmed prawn in the Americas causing widespread losses.
What are the characteristics of White Spot Disease?
Signs of White Spot Disease in aquaculture within tanks and ponds include:
- rapid onset of mass mortality (80% or more) in farmed penaeid prawns during the grow out period
- 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
Please note, that like any aquatic disease, diagnosis cannot be made without appropriate laboratory testing. For information on how to submit samples for diagnosis contact NSW DPI Aquatic Biosecurity on the numbers given below.
For further information on the characteristics of white spot disease see:
Prawns are safe to eat as White Spot Diseases does NOT pose any threat to human health or food safety.
Outbreak of white spot disease in Queensland – December 2016
In December 2016 White Spot Disease was detected in farmed prawns in south east Queensland. For further details of the outbreak see www.outbreak.gov.au/.
There is no evidence of White Spot Disease in NSW prawn farms or in wild caught prawns.
What is NSW government doing to protect NSW aquaculture and wild stocks from White Spot Disease?
NSW Department of Primary Industries (DPI) is working together with other jurisdictions (states, territories and the Commonwealth) to help minimise the risk of White Spot Disease spreading.
DPI has established a Control Order (PDF, 473.8 KB) that places restriction on the importation into NSW of any uncooked decapod crustaceans or polychaete worms from a designated area encompassing all affected areas in south east Queensland.
White Spot Disease is declared as Prohibited Matter under Schedule 2 of the Biosecurity Act 2015. This includes a duty to report the presence or suspected presence of white spot disease at any place to NSW DPI and strictly prohibits any dealings with this biosecurity matter or associated carriers.
What you can do to help prevent the spread of White Spot Disease
Information for recreational fishers and members of the public
- never use prawns intended for human consumption as bait. When fishing, always source products market as bait from a dedicated bait supplier, for example, from a tackle shop
- do not bring bait caught in south east Queensland to NSW
- dispose of your prawn waste (heads or shells) in general waste, never to our waterways
- be aware of bait showing signs of White Spot Disease and if concerned it may be diseased, do not use the bait and instead contact DPI Aquatic Biosecurity on the numbers provided below
- make ‘clean’ part of your routine, wash your vehicles and gear between waterways
- if you catch your own bait, use it only in the water from where it came
- if you are a recreational fisher, see important information for recreational fishers - use of prawns as bait
Information for prawn farmers
- follow your permit conditions, including those relating to biosecurity
- report any unusual mortalities or suspicions of White Spot Disease to a fisheries officer as soon as possible, and within 24 hours
- if you haven’t already done so, prepare a Biosecurity Plan, both to minimise the risks of aquatic disease entering your property and of it spreading if it does enter
- use separate equipment for different ponds or tanks throughout your property if possible
- disinfect and decontaminate equipment between use in different areas of your farm
- keep good records of stock movements, for both incoming and outgoing stock and for movements to different areas within the farm
- minimise unnecessary visitors to your production areas of your farm and find out where delivery trucks and other visitors have previously visited before accepting them on site
Information for seafood processors and bait suppliers
- be aware of the NSW Control Order (PDF, 473.8 KB) currently in place on uncooked prawns, decapod crustaceans (including lobstersm crabs, slipper lobsters, Moreton Bay bugs) and polychaete worms (including beach worms) originating from within an area between Caloundra and Tweed Heads south-east Queensland. For more information, see the NSW Control Order (PDF, 473.8 KB)
- ensure that you are not importing uncooked prawns, decapod crustaceans, or polychaete worms (for bait or human consumption) into NSW from within the affected area south-east Queensland, unless they have been treated in accordance with the NSW Control Order (PDF, 473.8 KB)
- uncooked decapod crustaceans destined for human consumption only (not bait) can move through the closure area and into NSW if they have originated from outside the closure area, 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.
- please note there are no movement restrictions on cooked decapod crustaceans that are securely packaged and transported directly to a point of sale in NSW. While cooking prawns inactivates the virus, freezing prawns does NOT kill the virus.
Information for commercial fishers
- the current NSW Control Order (PDF, 473.8 KB) prohibits movement into NSW of uncooked prawns, decapod crustaceans (including lobsters, crabs, slipper lobsters, Moreton Bay bugs) and polychaete worms (marine worms) originating from an area between Caloundra and Tweed Heads in south east Queensland. Uncooked decapod crustaceans destined for human consumption can move through the closure area and into NSW if they have originated from outside the closure area, 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. For the full extent of the restrictions please see the NSW Control Order (PDF, 473.8 KB).
- fittings used in the restricted area 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.
- there is no movement restrictions on cooked decapod crustaceans that are securely packaged and transported directly to a point of sale in NSW for human consumption
- to minimise risk of spreading disease ensure you adopt good biosecurity practices when travelling through the affected areas.
- report any signs of white spot disease to 1800 675 888
- updates can be found at www.outbreak.gov.au
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 disease to