White spot disease (WSD) found in Queensland prawns is highly contagious, lethal to crustaceans and has reduced prawn farm productivity by up to 40 per cent overseas.
The Queensland Government has now confirmed that the virus has spread into the wild prawns in Moreton Bay, off Brisbane.
Beginning in November last year, seven prawn farms on the Logan River, between Brisbane and the Gold Coast in south-east Queensland, have tested positive to the devastating virus and have effectively shut down.
Queensland’s chief biosecurity officer Jim Thompson said it was the first time the viral infection, which kills prawns but is harmless to humans, had reared its head in Australia.
“Australia has been the only major prawn-growing country that has not had white spot disease,” he said.
“It can cause significant mortality in farmed prawns. Over 80 per cent of prawns can die.”
Department testing results obtained by ABC Rural in January showed 70 per cent of the prawns being imported contained WSD.
The outbreak of WSD in Queensland is the biggest biosecurity outbreak to hit Australia’s aquaculture industry and jeopardises the future of Australia’s $80 million prawn farming sector.
Agriculture Minister Barnaby Joyce told 7.30 in January the prawn industry constitutes a $358 million a year import and domestic sector.
Ian Rossmann from GI Rural was the first farmer to detect white spot and described the experience as a “nightmare” after having to destroy $1 million worth of prawns in the lead up to Christmas.
“Anyone who purchases a green prawn from overseas from a white spot infected country, that can get into our waterways by bait, crab bait or even just throwing it into the water,” he said.
“We believe our waterway has been infected that way.”
How does white spot affect prawns?
Prawns with WSD may have a loose shell with a pink to red discolouration, and may gather near the surface of the water.
Infected prawns may also stop eating, become lethargic or swim differently.
One of the infected farms was run by Nick Moore who was forced by Biosecurity Queensland to destroy millions of prawns using chlorine.
7.30 witnessed chlorine being poured into one of Mr Moore’s ponds, where the water quickly changed colour and the prawns leapt out until the chlorine killed them.
“To watch them die like this is pretty bad, it’s as bad as gets actually,” Mr Moore said.
“The gills are getting torn apart by the chlorine, they’re trying to find oxygen and you’ll see them around the edges [of the pond]. The chlorine is stripping out the oxygen from the pond.”
What is happening with prawn supplies?
Australian authorities are still investigating how white spot disease spread to Australia, while prawn farmers have blamed Asian imports.
In early January, Barnaby Joyce suspended the importation of green prawns following infected product being found for sale in Australia.
“There’s a strong case that people have been swapping prawns,” Mr Joyce told 7.30.
“It’s just like doing urine swaps for rogue footy players.
“The [importers] were offering up a batch of prawns [for inspection] they knew full well didn’t have white spot and taking the others in the back door.”
The department has since taken all imported green, or uncooked, prawns off the shelves.
One of the largest prawn farms in Australia, Gold Coast Marine Aquaculture, lost 25 million black tiger prawns when it was forced to destock as part of the eradication program earlier this year.
As its general manager, Mr Moore said the facility could be shut down for more than a year.
“There are discussions with government now as to whether this whole region should hold off restocking,” he said.
“Not just until this November but the following November, to give us almost two years of no farming in this region.”
Last week, the Vietnamese Government accused Australia of “causing serious damage” to its prawn farmers and exporters, and has asked the Federal Government to reconsider the ban on uncooked imports.
Vietnam’s Deputy Minister of Industry and Trade, Tran Quoc Khanh, said it should be allowed to keep exporting raw prawns to Australia until there was proof foreign imports were the source of the outbreak.
“Vietnam requests Australia to provide adequate scientific evidence as soon as possible that shows a causal relationship between the prawn imports from Vietnam and the outbreak of white spot disease in Australia,” he said.
The Seafood Importers Association of Australia had previously said the ban had damaged Australia’s international trade reputation, but the Department of Agriculture defended the move, saying it was necessary to protect the nation’s aquaculture industry.
— with staff
Originally on ABC News