The highly contagious White Spot disease that can affect crustaceans including prawns, yabbies and crabs has been detected at a second Palmers Island prawn farm in a month, prompting the Department of Primary Industries to extend a control order to prevent any further spread.
The NSW Department of Primary Industries DPI detected the first white spot outbreak at another Palmers Island prawn farm on February 12, issuing a control order on February 16.
The control order prevents the movement of raw, uncooked green prawns out of an area defined as the Clarence River Control Zone, while containment, source detection and surveillance activities are underway.
The latest White Spot detection at the second Palmers Island prawn farm was made on February 25, which NSW Chief Veterinary Officer, Sarah Britton said was confirmed by laboratory tests.
“Following two confirmations of White Spot and the need to continue wild crustacean surveillance, the control order has been extended until 29 March 2023,” she said.
“The extended control order allows us to gather more evidence to help determine the significance of previous results.
“Extended surveillance will provide critical data for tracing and evidence to inform requirements for future management approaches.
“NSW DPI is working with both farms to ensure biosecurity directions are in place to eradicate White Spot through accelerated destocking and destruction, which has now been completed at the first infected farm.”
While there is there is no current evidence of active White Spot infection in NSW wild prawn populations, trace levels of White Spot DNA were found in a small number of wild caught prawns from the Clarence Estuary.
Continuing surveillance sampling of wild caught prawns and crustaceans will determine the significance of these results.
White Spot poses no threat to human health, it is a highly contagious viral infection which affects crustaceans and can cause major mortalities in farmed prawns.
NSW prawns remain safe for human consumption and consumers can continue to purchase NSW prawns from local seafood suppliers.
No raw, uncooked prawns and polychaete worms, including seafood and fishing bait, caught on or after 12 February 2023 can be moved outside the Clarence Estuary.
Sequencing tests indicate the White Spot strain from the NSW 12 February 2023 detection is strongly similar to the strain detected in NSW in August 2022 and is not the same as the south-east Queensland detection in 2016.
White Spot was first detected in NSW at a Palmers Island prawn farm in August 2022, and eradicated in September 2022.
The disease is caused by people using cheap, imported prawns that carry White Spot as bait, and the highly contagious virus then spreads into estuaries and nearby prawn farms.