The Queensland prawn farmers forced to destroy million dollars worth of stock due to an outbreak of white spot disease (WSD) are blaming imported green prawns, and believe the incident is a ‘wake-up call’ for the nation’s entire biosecurity system.
The three farmers said they were convinced their prawns got WSD from crustaceans in the adjoining Logan River, from imported prawns either used as fishing bait or discarded into the river.
“I just find it so disturbing that we in Australia, with a clean bill of health, have been importing an exotic disease like this and authorities have let it go by,” Alberton prawn farmer Ian Rossmann said.
“It is a big wake-up call to Australia.
“We have a wonderful country free of most exotic disease and it is such a hardship when it falls on farmers in particular because our livelihoods are in jeopardy.”
WSD is a viral infection that affects crustaceans and can cause crop losses of around 80 per cent in farmed prawns.
The south-east Queensland outbreak is the first confirmed case of WSD in an aquaculture setting in Australia, although the disease is well established in Asia and the Americas.
PHOTO Prawns with white spot disease have been found in Queensland’s Logan River and on three prawn farms. SUPPLIED: BIOSECURITY QLD
Ian Rossman 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.
“I’m very confident it came from the [Logan] River, we pump water into the farm from the river and tests have shown it is positive in the river,” Mr Rossman said.
“We have been very concerned about white spot introduction into Australia through green prawn imports and we believe 100 per cent that that is where it came from.
“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.”
“We believe our waterway has been infected that way.”
The Federal Department of Agriculture has confirmed 73 imported consignments had tested positive for white spot since May this year, although the majority have been destroyed or exported.
It said it had a “rigorous testing regime in place”, which required every consignment of imported raw frozen prawns to be tested for white spot disease.
The department also said imported prawns could not be sold as bait and must be peeled and have the head off.
“It is premature and counterproductive to make any assumptions [about the virus’s entry into Australia] at this time,” a department spokesperson said.
Only six wild prawns from the Logan River have been found to have a “low level” of white spot syndrome virus DNA, according to Biosecurity Queensland.
Biosecurity Queensland said currently there was “no reason to believe that the virus that causes white spot disease is established in local wild crustacean populations including prawns caught for bait”.
Despite that, Elwyn Truloff from Truloff Prawn Farms at Alberton said he was adamant imported prawns led to the infection on his farm.
He said he is angry at authorities for not banning fresh prawns from overseas years ago.
“This is the first harvest we have missed in 27 years and it has given us a real boot in the stomach, and it is all because authorities have not followed protocol by getting testing done right,” Mr Truloff said.
“We have told them hundreds of times [to stop imports] but it falls on deaf ears, that is the problem.”
A spokesperson for Biosecurity Queensland said the authority was yet to determine exactly how white spot made it to Australia, and investigations were ongoing.
Regardless, Mr Rossmann said the importation of fresh prawns was not worth the risk.
“We have other industries as well saying don’t bring this green product or unprocessed produce into Australia, it is so dangerous,” Mr Rossman said.
Other pathways for the disease
Mr Rossman said he and the other two affected farmers have ruled out other possible pathways for the disease, such as hatcheries and animal feed.
He said it is unlikely the disease came onto his farm in prawn feed, as the food is heated to 90 degrees during processing and such temperatures would have killed the virus.
Mr Truloff was the third farmer to discover white spot on his farm, and said he and the other affected farmers have also ruled out prawn hatcheries as a source of the infection.
“We have our own hatchery run by my two boys and we have proven it hasn’t come from our hatchery because we send prawns to three other farms and they don’t have the disease, it’s just us,” he said.
“It has definitely come from the wild.”
PHOTO: A pond on a prawn farm wiped out by white spot disease, south of Brisbane
Simon Rossman was the second farmer to discover the disease on his farm, and also rejected the idea that hatcheries were the source.
“I’m 100 per cent convinced, because the hatchery we source from supplies other farms up the coast of Australia and they haven’t contracted the disease,” he said.
Mr Rossmann and his brother had only been farming for three years and described the outbreak as a massive setback in their agricultural careers.
Calls for compensation
The farmers were also angry at having to destroy all of their crop, despite alleging that some ponds showed no symptoms of WSD.
The Australian Government’s Aquavet plan for water veterinary emergencies stated farmers were allowed to still harvest stock that was free of the disease.
“The Government’s legislation, the Aquavet plan, says [authorities] will only destroy infected ponds, but they progressed to kill all our healthy livestock that was only weeks away from making good income,” Simon Rossman said.
“Most of our ponds that were destroyed didn’t have any sign of disease, all the tests came back negative, but they destroyed them anyway.”
Authorities pumped about 700,000 litres of chlorine into 34 ponds across the three farms to kill the infected prawns.
“We pleaded to leave all the other ponds alone, so we could try to grow them out and that we would know if it had spread,” Mr Truloff said.
“But instead of having just three or four ponds to cull, [authorities] now have the whole damn farm to deal with because they don’t know if it was in the other ponds [before they decontaminated them].”
The Aquavet plan stated that ponds of juvenile prawns that displayed no evidence of exposure to WSD could be grown to harvest size, provided the chance of being infected was “acceptably low”.
PHOTO Queensland Fisheries are patrolling the Logan River to stop prawn fishing to prevent the spread of white spot.
The plan stated this “might provide an attractive option for farmers that reduces the financial burden of forced destruction of stock”.
However, a spokesperson for Biosecurity Queensland said the Aquavet plan was only used as a guide and could be updated depending on the degree of risk.
“The management of white spot disease is in accordance with the nationally agreed Emergency Animal Disease Response Plan (EADRP), which requires that all ponds on an infected farm be destocked,” the spokesperson said.
“The risk associated with leaving individual ponds untreated is too great, and the priority is to protect the immediate environment and the broader industry from any potential source of infection.”
Mr Truloff said he wanted to be compensated for the loss of juvenile stock, which he estimated would have been worth $4 million come harvest time.
“We will be [seeking compensation] because I think we are entitled to quite a bit back because we have lost $1 million [in stock],” he said.
Mr Truloff also said he was still having to pay thousands of dollars per day in operating costs, despite not having an income.
“We are also obliged to keep all the paddles going in the ponds to stir the chemicals through to kill them all,” he said.
“Just with electricity and feed it is costing us $5,000 a day.”
Queensland’s agriculture minister, Bill Byrne, has previously ruled out compensation and now the Australian Government has too.
A spokesman for the Federal Department of Agriculture said “as there are no national emergency response arrangements in place for the management of aquatic animal diseases, reimbursement of costs for lost stock will not be available to affected parties”.
The Logan River is home to eight aquaculture businesses that collectively produce 25 per cent of Australia’s farmed prawns, and 40 per cent of Australia’s farmed tiger prawns.
The five remaining farms are free of any signs of infection, however authorities say they will continue to monitor those sites extensively.