Tasmanian Inquirer – Salmon company confirms use of antibiotic at hatchery in Hobart’s water catchment

Tasmania’s second-largest salmon producer used a controversial antibiotic to treat a disease outbreak at a hatchery in Hobart’s water catchment, but made no public announcement to alert downstream users.

Huon Aquaculture told Tasmanian Inquirer it used oxytetracycline (OTC) to treat a mid-January disease outbreak caused by “an acute spike in water temperatures” at the Meadowbank hatchery. The hatchery is located on the bank of the Derwent River about 20 kilometres upstream of New Norfolk.

Huon’s environmental licence [Pdf] for the hatchery, issued by the Environment Protection Authority (EPA) in September 2022, requires the company to monitor and report data on 16 parameters but not antibiotic residues. The licence permits Huon to hold up to 160 tonnes of fish at the hatchery, which is a “flow through” plant that takes water from the river just downstream from the Meadowbank dam and discharges wastewater back into the river.

Neither Huon nor the EPA publicly disclosed the use of the antibiotic at the hatchery, or responded to requests for details on when the drug was first used and whether the treatment was still underway. A Huon spokesperson said the company voluntarily disclosed the use of the antibiotic to the EPA, which “enabled the EPA to implement a stringent monitoring framework”.

Meg Webb, an independent member of the Legislative Council and the chair of a 2020 inquiry into finfish farming, said the secrecy was “shockingly inadequate and unacceptable” and did not meet community expectations. “Tasmanians will be justifiably angry that yet again such developments have to be dragged out into the light of day,” she said.

The EPA said it had put measures in place to monitor antibiotic residues and would publish the results on its website.

Contrasting standards

The secrecy surrounding antibiotic use at the hatchery is at odds with recent practice in disclosing drug use in marine fish farms. After growing controversy over the lack of public notification of antibiotic use, the EPA agreed in early 2025 to provide real-time disclosure for each lease, including the duration of the treatment and guidelines for sampling for residues. It had previously published only final monitoring reports, and not until months after treatment was completed.

“We also need to know whether this was an isolated incident, or whether antibiotics have been used in freshwater hatcheries previously.”

Meg Webb.

Webb said Huon and the EPA should immediately disclose what disease was being treated, when the outbreak was detected, when treatment with OTC began and if it is still underway. She said the company should also disclose when it informed the EPA. “We also need to know whether this was an isolated incident, or whether antibiotics have been used in freshwater hatcheries previously,” she said.

The World Health Organization has classed OTC as “highly important” for human health. It warned overuse of OTC in the food industry could lead to the development of antibiotic-resistant “superbugs”, which it described as “one of the biggest threats to global health”. The salmon industry has used more than 32 tonnes of antibiotics, predominantly OTC, in Tasmanian marine waters since 2003.

In November 2025, the salmon industry received approval to use Florfenicol as an alternative to OTC, which was becoming less effective. The director of public health, Dr Mark Veitch, said recreational fishers could avoid exposure to antibiotic residues by not eating fish caught within 3 kilometres of  treated salmon cages while the drug was in use and for up to 21 days afterwards. The government publishes a map illustrating the 3-kilometre zones around marine leases currently treated with an antibiotic.

The EPA has not published details of the antibiotic use at Meadowbank Hatchery or the monitoring guidelines. Nor is there public health advice or a map showing the affected area for recreational fishers or other downstream users. Webb said she was concerned whether the Health Department had been notified about the use of OTC at Meadowbank, or at other hatcheries “that we have not been informed about”.

The EPA said new monitoring requirements for antibiotic residues would apply to all freshwater hatcheries in the state. It did not respond to a request for clarification on when this would be included in licence conditions.

None of the other five salmon hatcheries discharging effluent into the river or its tributaries is legally obliged to monitor antibiotic residues in wastewater.

Tasmanian Inquirer asked the Environment Minister, Madeleine Ogilvie, whether she had been told of Huon’s antibiotic use at the Meadowbank Hatchery. She did not respond.

This is not the first time the operation of the Meadowbank hatchery has been scrutinised. In May 2024, the EPA sent a warning letter to Huon over the breach of a licence condition at the hatchery. It is unclear what the breach was.