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Despite repeated warnings from scientists, the Tasmanian salmon industry has been run with exemptions to biosecurity regulation and under a regime that was weakened at its urging. By Gabriella Coslovich.
Biosecurity warnings ignored by the Tasmanian salmon industry
Scientists warned the Tasmanian government of the risk of catastrophic disease-related fish deaths across the state’s salmon farms as early as 2017, noting the biosecurity standards governing the industry needed to be significantly increased.
Instead of boosting biosecurity, however, the government, under pressure from the salmon industry, weakened several standards and provided many exemptions to the new biosecurity program introduced in 2023.
Dr Christine Coughanowr, one of the independent scientists who pushed the need for stronger standards, is calling for an independent investigation into the biosecurity failure that has allowed Piscirickettsia salmonis to surge across south-east Tasmania, killing thousands of tonnes of farmed salmon.
The infection has now reached Storm Bay, east of Bruny Island, despite assurances from Salmon Tasmania: the industry lobby’s chief executive, Luke Martin, told The Saturday Paper last week “the elevated mortality event is over”.
Coughanowr asks how the bacteria could have reached Storm Bay, which is physically separated from the outbreak in the D’Entrecasteaux Channel. She notes that the salmon leases at Trumpeter Bay have some of the largest pens in the world – 240 metres in circumference.
“Mass mortalities in the big pens would be disastrous,” she says. “And will antibiotics be able to stop this outbreak, given their apparent failure to do so in the channel? It’s nice to say that the outbreak has reached its conclusion, but not if it’s getting into Storm Bay leases.”
Three years ago, the Tasmanian government invited public submissions on the salmon industry’s draft biosecurity standards and received 11, including from the Tasmanian Independent Science Council, which Coughanowr co-chairs; the University of Tasmania’s Institute for Marine and Antarctic Studies (IMAS); the RSPCA; and Tasmania’s three salmon farming companies, Tassal, Huon Aquaculture and Petuna Aquaculture.
IMAS was particularly concerned that new biosecurity measures would not apply to existing marine farms – for example, fish farms already running would not need to be separated by a safe distance of at least four kilometres from other farms holding fish of a different year class.
IMAS recommended that unless existing farms could be brought up to scratch within a certain timeframe, such as five years, the farms should be closed.
The institute was also troubled by the many exemptions allowed in the new biosecurity standards, stating that “exemptions should be considered carefully as they may suggest that the biosecurity standards are less important than operational and commercial concerns”.
The government responded that revised distances between marine farms should not apply to existing operations because of the need “to maintain business continuity”.
Similarly, the government claimed it would not be possible to require existing farms in one biosecurity zone to go fallow at the same time, to allow the marine environment to recover from the impact of farming or disease, because this would risk “significantly compromising business viability”.
Coughanowr says the government response contained “a lot of emphasis about protecting the status quo and economics of the industry rather than looking forward and managing biosecurity risks”.
With mass deaths across salmon leases, Coughanowr says the industry’s resistance to proper regulation and the government’s compliance with these wishes have been an own goal.
“It’s in part because the government allows the industry to self-manage a number of aspects of biosecurity. So, if they are not all playing by the same rules, and there is limited oversight, it’s not unexpected that something like this happens,” she says.
“If you are trying to protect an industry, and jobs, which the government says it is trying to do, you have to develop and enforce really high biosecurity standards.”
Coughanowr also points to the increase since 2019 of large wellboats servicing Tasmania’s salmon farms, moving salmon between leases.
Under Tasmania’s current biosecurity standards, salmon must not be moved between marine farms in different biosecurity zones, although an exemption exists that allows fish to be moved from the South-Eastern Marine biosecurity zone to the Eastern Marine biosecurity zone, in one direction only.
The Saturday Paper understands that experts within government argued against the movement of fish and vessels between these two biosecurity zones but were overruled because of pressure from the salmon industry.
International studies have also found that stocking densities are critical to the impact of disease, with salmon in high-stocked pens becoming stressed and immunosuppressed, and more likely to suffer skin lesions, which makes them more susceptible to P. salmonis, an opportunistic pathogen.
“Everyone realises that overstocking leads to increased disease and mortality,” Coughanowr says. “A key question is, what are the actual stocking rates being adhered to in Tasmania? Interestingly, for most of Tasmania, the maximum allowed stocking limit is 15 kilograms per cubic metre, which would be about three mature fish in one cubic metre. But in the Channel/Huon region, the allowed limit is 25 kilograms, and also in Okehampton Bay. I don’t know why that is.
“That seems counterintuitive, as the channel is relatively poorly flushed compared to say Storm Bay, and the biosecurity risks would be much higher due to the large number of farms in close proximity. Similarly, Okehampton is on the east coast, with increasingly warm water temperatures, stressful for salmon, as well as jellyfish and harmful algal blooms. So why would a high stocking density be allowed here?”
As The Saturday Paper revealed last week, Tasmania’s chief veterinary officer, Kevin de Witte, quietly downgraded the biosecurity status of P. salmonis from “prohibited matter” to “declared animal disease” on January 16, thus lowering the obligations of the salmon industry to deal with the disease outbreak.
When The Saturday Paper called Salmon Tasmania chief Luke Martin this week, wanting to know whether the salmon industry had pressured the Tasmanian government to downgrade the bacteria’s biosecurity status, he said: “I think I am just about done with you. I reckon you have enough from us.”
In a later email response, he said the industry had managed the “summer mortality event” in accordance with regulatory and reporting requirements. He said P. salmonis is not a food safety risk.
“The Department of Natural Resources and Environment Tasmania is responsible for decisions about disease listings,” he said. “Salmon Tasmania and the industry does not ‘lobby’ the Tasmanian Government in relation to their decisions on these independent and science-based decisions.”
The Saturday Paper emailed Tasmania’s minister for business, industry and resources, Eric Abetz, and the minister for primary industries and water, Jane Howlett, asking whether the Tasmanian salmon industry pressured the government to downgrade the biosecurity status of P. salmonis.
A government spokesperson responded: “The proposed reclassification is an operational matter for the Chief Veterinary Officer under his delegation. The Minister was not briefed in advance. The Tasmanian Government and the Department of Natural Resources and Environment Tasmania is not aware of any advocacy by the salmon industry in relation to this bacteria and its classification. The reclassification should not be disingenuously referred to as a ‘downgrade’.”
In a separate email, a spokesperson for the Department of Natural Resources and Environment said the reclassification of P. salmonis began nine months ago and involved genome sequence analyses conducted by Tasmania’s Centre for Aquatic Animal Health and Vaccines.
The spokesperson emphasised changing P. salmonis from a prohibited exotic disease to a declared disease was not a “downgrade” but rather a reclassification “based on scientific assessment and reflective of eradication of the disease not being realistic as it was now considered a naturally occurring bacterium. Declared diseases are taken seriously and can be treated as the highest biosecurity risk based on scientific assessment.”
The spokesperson reiterated that P. salmonis did not pose a human or health food safety risk: “The Chief Inspector of Primary Produce Safety has determined that P. salmonis is not a prescribed disease under the Primary Produce Safety (Seafood) Regulations 2023.”
Last Friday, Salmon Tasmania announced that Luke Martin would be stepping down from his role as chief executive after less than two years in the job. His replacement is Dr John Whittington, a former secretary of the Tasmanian Department of Primary Industries, Parks, Water and Environment and the current chief executive of Blue Economy CRC, an industry-focused research centre with a particular interest in offshore aquaculture and renewable energy production.
Martin, meantime, will be joining the office of Tasmanian Labor leader Dean Winter.
When The Saturday Paper asked Martin how much longer he would be in the role of chief executive at Salmon Tasmania he said: “I am not sure yet. Just until we manage a bit of a handover. We announced it because I needed to give notice and we secured my successor. We are just working through that now, so we don’t have a firm date.”
The announcement followed an interview with The Saturday Paper in which Martin admitted that salmon harvested from diseased pens were being sold for human consumption, but Martin says there is no correlation.
“I’m certainly leaving with my head up,” he says. “Timing in this space is always going to be challenged because of the scrutiny on salmon, and when you’re dealing with professionals trying to line up their timing to be able to depart long-term roles or move into new roles. The scrutiny on the industry is intense at the moment because of the election and obviously the mortality event and Macquarie Harbour.
“From the industry’s perspective, this is a good transition that will be managed as well as we can, and we won’t miss a beat. And John is an outstanding outcome because he has as much experience across all nature – of the science, the regulation and innovations occurring in the industry – as probably any person in Australia.
“And from my perspective, I’ll be able to go to Strahan for the rest of my life, and I’ll get on fine with those people in that place, and I did what I did to save their jobs and that’s something I’m very proud of.”
This article was first published in the print edition of The Saturday Paper on April 12, 2025 as "Fishy business".
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