13/2/26: Water utility ‘confident’ Hobart drinking water is antibiotic-free after salmon disease outbreak
by Clancy Balen ABC Tasmania
https://www.abc.net.au/news/2026-02-13/salmon-disease-outbreak-antibiotics-river-derwent/106330724
Tasmania’s water provider says there is no risk of antibiotics entering Hobart’s water supply, following Huon Aquaculture’s use of oxytetracycline in a hatchery connected to the River Derwent.
The salmon giant administered the medication as a “last line of defence” after an increase in deaths at its Meadowbank hatchery located 40 kilometres upstream from TasWater’s Bryn Estyn water treatment plant.
The treatment plant provides water to much of the Greater Hobart area.
A TasWater spokesperson said the utility was confident its water treatment process, combined with the distance between the treatment and hatchery, “removes any risk of antibiotics entering our treated water supply”.
“TasWater undertakes extensive testing of its water supply,” the spokesperson said.
“We don’t specifically test for antibiotics, as we see there is minimal risk of antibiotics making it into our drinking water supply.”
In a statement, Tasmania’s Director of Public Health, Mark Veitch, said based on available information, he determined “there was no risk to human health” from the limited use of the antibiotic.
Dr Veitch said the treated feed was administered to fish contained in tanks rather than in open water, sediment management at the hatchery would minimise the release of antibiotic, and the levels of antibiotic would be diluted in the waterway.
A Huon Aquaculture spokesperson confirmed the medication was administered over two periods at the Meadowbank hatchery, between January 21 and February 9.
The spokesperson said the company advised the Tasmanian Environment Protection Authority (EPA) on January 20.
“The notification period is in line with government reporting expectations in the marine environment, when veterinary advice determines urgent treatment is necessary,” they said.
The use of antibiotics was only made public following a report by the Tasmanian Inquirer.
There is no current regulatory requirement to make the use of antibiotics in freshwater hatcheries public.
EPA flags reporting changes
An EPA spokesperson said the use of antibiotics at the Meadowbank hatchery had “enabled the EPA to consider and implement new regulatory requirements”.
These include requiring the EPA to be notified of antibiotic treatments, and monitoring for antibiotic residues to be undertaken, in freshwater environments.
The EPA spokesperson said the new regulations would be introduced by the end of March, and results would be published on its website.
The changes have failed to allay concerns from Tasmanian Independent upper house member Meg Webb, who was critical of the initial secrecy surrounding the use of antibiotics.
“While some information gaps are finally being filled in, these recent statements fail to address why the public were kept in the dark in the first place,” Ms Webb said.
“Nor do they address a range of concerns associated with the antibiotic oxytetracycline, such as potential for antimicrobial resistance.”
Tasmanian Greens leader Rosalie Woodruff on Wednesday said the EPA’s new reporting commitments fell short.
“The EPA should be notifying the public in real time, when antibiotics are being used in the drinking water supply and in the marine environment,” Dr Woodruff said.
“They’ve got the capacity to do that; that’s the minimum that’s required.”
Alternative to flow-through system
Freshwater hatcheries are used by salmon companies to raise juvenile fish called smolt, before they are transferred to marine pens.
Huon Aquaculture’s Meadowbank facility is a flow-through fish farm, meaning the water flows through the pens before being discharged back into the water source.
Independent scientist and former Derwent Estuary Program chief executive Christine Coughanowr said while treatment methods were used at flow-through hatcheries to reduce pollutants, they would not eliminate all the environmental risks.
“Whatever else is used in the facility, whether it be antibiotics or disinfectants, hormones, salt water sometimes — that’s all picked up in the water that flows through,” Ms Coughanowr said.
“Operationally, it’s a bad idea to have to use antibiotics in a flow-through fish farm where it’s discharged to a waterway upstream of public drinking water.”
An alternative to the flow-through system is a “recirculation” system, which Ms Coughanowr said used less water.
“It provides for a lot more control over water quality within the fish farm and much lower emissions, and far lower water use,” she said.
In its Salmon Industry Plan 2023, the Tasmanian government flagged the development of a framework to transition flow-through hatcheries to recirculating systems as a “priority item”.
A Department of Natural Resources and Environment spokesperson said consultation on draft standards for the plan would occur later this year, and would involve consideration of the latest technical and science-based expertise and data.
The spokesperson said the majority of industry hatchery production already used recirculating systems.
Antibiotics use continues at marine pens
Oxytetracycline has been used in Tasmanian and Australian marine environments previously, but it isn’t the only antibiotic used in the aquaculture sector.
Last November, the Australian Pesticides and Veterinary Medicines Authority (APVMA) confirmed the emergency approval for another type of antibiotic, florfenicol, in salmon pens along the Tasmania’s south-east coast.
The emergency application was made by the salmon industry following a mass mortality event caused by an endemic bacterial disease, which killed up to 15,000 tonnes of salmon between January and April last year.
That same month, it was revealed 700 kilograms of florfenicol was used in the D’Entrecasteaux Channel over a 13-day period.
The permit to administer the antibiotic will expire on August 31.
APVMA chief executive Scott Hansen told a Senate hearing on Tuesday that more information would need to be supplied by the salmon industry to extend the permit.
“We’ve been told their long-term ambition is registration of the product, and that they’d be collecting data as part of these permits to be able to support that application,” Mr Hansen said.
“They would need, for a broader ongoing registration, a lot more information about any microbial resistance.”
The World Health Organisation has described “antimicrobial resistance” — caused by antibiotic “misuse and overuse” — as “one of the top global public health and development threats”.
Mr Hansen said the industry could apply for another short-term permit to administer the antibiotic.
“That’d be judged on the merits of the information they provide,” he said.
Huon Aquaculture confirms antibiotic use in salmon hatchery on River Derwent
Feb 10 2026 by Jano Gibson Adam Holmes ABC News
There are calls for the public to be made aware of antibiotic use in Tasmania’s freshwater hatcheries after Huon Aquaculture recently used oxytetracycline to treat diseased salmon.
There are no disclosure requirements regarding the use of antibiotics in freshwater facilities, despite more stringent rules applying to the antibiotic florfenicol in coastal marine fish farms.
Details of Huon Aquaculture’s use of antibiotics at its Meadowbank hatchery on the River Derwent were only made public after a report by the Tasmanian Inquirer.
On Tuesday, Huon Aquaculture told ABC Mornings it deployed antibiotics as a “last line of defence” after an increase in mortality at the hatchery.
The issue was caused by an intestinal infection, rather than the bacterial disease that led to a mass die-off event in coastal waterways in the state’s south-east last summer.
“Back in mid-January, we saw a spike in water temperature,” the company’s general manager of aquaculture, Depha Miedecke, said.
“Things got quite warm and subsequently we saw an increase in mortality and this was caused by intestinal bacterial infection that can sometimes affect salmon and other fish.”
Ms Miedecke said the medication was given to two cohorts of fish over a 20-day period under veterinary advice.
The Meadowbank hatchery is about 20 kilometres upstream from TasWater’s Bryn Estyn water treatment plant, which is the primary source of drinking water for Greater Hobart.
The township of New Norfolk is several kilometres further along the River Derwent.
While downstream users were not notified, Ms Miedecke said the company chose to be “proactive” and “transparent” by making a voluntary disclosure to the Environment Protection Authority (EPA).
“The use of antibiotics in freshwater is very rare, so it’s certainly not something we do regularly at all,” she said.
“We, in this case, decided to voluntarily speak with the EPA about it.”
In a statement, the EPA said antibiotic residue monitoring had been put in place following the disclosure.
“The use of antibiotics at Meadowbank Hatchery was self-reported by Huon Aquaculture, noting there is no current regulatory requirement to do so,” the statement reads.
“Accordingly, the EPA has put appropriate environmental conditions in place, including antibiotic residue monitoring at Meadowbank Hatchery.
“These regulatory requirements will apply across all freshwater hatcheries across the state, strengthening the EPA’s regulatory framework.
“Consistent with EPA practice, monitoring results will be published on the EPA website.”
MLC criticises ‘murky lack of transparency’
Oxytetracycline is commonly used to treat diseases in agricultural and aquacultural settings, as well as for human health.
The World Health Organisation has categorised it as a “highly important antimicrobial”.
But the WHO also notes that “antimicrobial resistance”, caused by their “misuse and overuse”, is “one of the top global public health and development threats”.
Independent upper house member Meg Webb said the public should not have to rely on voluntary disclosures from salmon companies about the use of antibiotics in freshwater.
“We’ve got here a really unfortunate murky lack of transparency,” she told ABC Mornings.
“This is why we need full transparency about this.
“We need to have people who are experts looking at this, we need the community to know that full information is being provided and assessed.
“And that’s really part of building public confidence and a social licence for this industry.”
‘Real-time updates’ in place for florfenicol
Oxytetracycline was used during the mass mortality event in coastal salmon pens early last year, but Huon Aquaculture had complained it had been “largely ineffective”.
The industry was granted approval in November to use a different antibiotic, florfenicol, in south-eastern waters, and has since applied it in pens in the D’Entrecasteaux Channel and off the north-west coast of Bruny Island.
“Real-time updates” showing when and where florfenicol is used are listed on the salmon companies’ websites.
A monitoring system was brought in for baseline and regular testing at various intervals, including the water column and wild fish.
When approval was granted, director of public health Mark Veitch advised the public that if they wished to avoid antibiotic residue, they could avoid consuming fish caught within three kilometres for 21 days.
During the application process, the industry argued that florfenicol had a range of advantages over oxytetracycline because it required lower dosages, lower levels were excreted by fish and it had lower toxicity for aquatic organisms.
Industry ‘heavily regulated’: Health Minister
The Greens called on the government to mandate real-time disclosures for all antibiotic use in Tasmanian waters.
“Instead of allowing Tasmanian waterways to be pumped with antibiotics, and leaving the community in the dark about it, the Liberal government should immediately require companies to report real-time antibiotic use and to destock diseased salmon farms,” Greens MP Tabatha Badger said.
Health Minister Bridget Archer said antibiotic use was “heavily regulated” in Tasmania’s agricultural and aquacultural industries.
She said she had no concerns about public health risks relating to the use of antibiotics.
“Antibiotics, whether they are in veterinary use or in industry use in the salmon industry, are heavily regulated.
“And they are regulated with regard to their public health use as well. And we would expect those regulations would be adhered to.”