The exotic white spot virus that devastated South-East Queensland prawn farms is now killing wild prawns and small crabs in the Logan river and has become widespread in Moreton Bay.
- Surveys confirm white spot virus is killing wild prawns and small crabs
- White spot disease does not harm humans
- The disease has spread since an initial outbreak on Logan prawn farms in 2016
The Federal Government is reviewing its import requirements for prawns, and a leading aquatic disease expert warns that a dangerous double standard favouring importers over Australian fishers and aquaculture farmers is leaving the country wide open to the introduction of more dangerous viruses.
In a survey finalised for the Fisheries Research and Development Corporation late last year, Dr Ben Diggles discovered dead banana prawns and small crabs in waterways surrounding the Logan river — and live virus in small crustacean species in the marine food chain in Deception Bay, well away from the original incursion.
“We looked at a whole range of crustaceans that aren’t commercially significant because they’re too small.
We found it was throughout many of those other species so it’s within the food chain and unfortunately it looks like it’s here to stay,” the aquatic disease expert said.
Humans can’t be harmed by the highly infectious white spot virus which affects prawns, yabbies and crabs.
The bad news that it continues to spread in east coast waters comes as pressure mounts to prevent emerging aquaculture diseases entering Australia, from countries where biosecurity is not always enforced on prawn farms.
On Friday, submissions closed on the Federal Government’s draft review of quarantine risks posed by “prawns imported for human consumption”.
Dr Diggles, prawn farmers, bait and wild catch fishers and the seafood industry association have urged the government to force importers to cook prawns to kill white spot and other emerging aquatic diseases that aren’t even being tested for in Australia.
“Having one rule for one group and much stricter rules for Australian businesses and lax rules at the international border fails the pub test,” Dr Diggles said.”
Cooking would cut risk
A 2016 white spot outbreak forced all but three of seven prawn farms on the Logan river out of the industry at a time when demand for sustainably farmed Australian seafood is booming.
Australia’s inspector-general of biosecurity, Dr Helen Scott-Orr, found a major biosecurity failure likely led to the outbreak, by allowing huge quantities of white-spot infected raw prawns to be sold in supermarkets.
Freezing does not kill prawn diseases and the Australian domestic level of protection requires cooking of all prawns and crabs destined for human consumption, from a white spot control zone stretching from Caloundra to the New South Wales border.
Cooking would end the risk of recreational fishers spreading viruses by using potentially diseased green imported prawns and prawn products as bait, burley and in crab pots.
Recreational fishing risks
“They’re kidding themselves if they think people aren’t going out there and using that stuff, no matter how many campaigns they’re doing,” Tweed Bait general manager, Matthew Poile said.
Aside from last year, when the Federal Government covered expenses, Mr Poile estimated that irradiation costs to prevent the spread of white spot in bait cost his company $500,000 a year.
On the banks of the Logan river, Gold Coast Tiger Prawns has had to halve its stocking rates and spend hundreds of thousands of dollars improving filtration to reduce the risk of the virus entering its ponds from infected river water.
The multi-award- winning company’s improved biosecurity measures continue post-harvest, with all prawns cooked before leaving the property.
“It’s all about biosecurity and keeping pests out of Australia, it’s obviously a much cheaper and better option than managing them (forever) once they’re here.”
A Federal agriculture spokesperson said the department was considering a range of risk management measures for imports, including cooking but added, “Australia has an international obligation to apply the least trade- restrictive biosecurity measures to achieve Australia’s appropriate level of protection”.
The Commonwealth Government has spent $20 million to assist affected prawn farmers and an additional $1.74 million to the Queensland Government and affected industries.
In the next five years, the Australian prawn industry expects to sell $500 million worth of sustainably farmed prawns and invest a further $400 million in farm expansions in Northern Australia.
Australian prawn farmers association executive officer Kim Hooper said the industry needed improved protection.
“We don’t have a lot of these other pathogens currently in Australia. We want to keep it that way. We love to be able to provide such a high quality, sustainable product to Australia,” Ms Hooper said.
Of 718 tests finalised on imported prawn consignments last year, four tested positive for white spot syndrome virus and were re-exported.
A further 25 tests are pending.
Unlike imported marinated prawns, breaded, crumbed and battered prawns are currently not tested for the disease.