Five tonnes of antibiotics used to combat disease in salmon

The industry's use of the antibiotic to combat disease in salmon was halted after traces were found in wild species kilometres away. (ABC News: Maren Preuss) Salmon Tasmania says 5.4 tonnes of the antibiotic florfenicol was used to treat a bacterial disease last summer, which resulted in the deaths of 9,000 tonnes of salmon. The Tasmanian Greens say the figure is a "shocking indictment" on the salmon industry. Salmon Tasmania says the industry is committed to "responsible antibiotic management" and will continue to invest in vaccines and selective fish breeding programs. Link copiedShareShare articleTasmania's salmon industry has confirmed over 5,000 kilograms of antibiotics were used last summer to treat a disease outbreak which killed 9,000 tonnes of farmed fish over the first three months of this year. The final figures have been released several months after the salmon industry was banned from using the antibiotic, known as florfenicol, by the federal agency responsible for administering it due to low levels of the drug being detected in other marine species. Until now, both the industry's peak body, Salmon Tasmania, and the state's independent environmental regulator, Environment Protection Authority (EPA) Tasmania, have been unable to provide a figure for the total amount, despite the antibiotic being banned in March. AbbeyFlor florfenicol premix for pigs was licensed for use on Atlantic salmon in Tasmania, before that licence was revoked. (Abbey Laboratories) The salmon industry said it would forge ahead with a "multi-strategy approach" to fish health, involving future antibiotic use, along with vaccinations and selective breeding. Tasmanian Greens MP Vica Bayley said the final figure was a "shocking indictment on the industry" and the dumping of five tonnes of florfenicol into waterways to deal with the disease was not a credible solution. "We don't think it's worth it full stop," Mr Bayley said. The Tasmanian industry's stocks of Atlantic salmon were hit hard by bacterial outbreaks last summer. (Huon) The Greens have long advocated for the mostly marine-based industry, which is located primarily in coastal waters in the state's south-east and west coast, to move all operations on land. The salmon industry, which has flagged its intention to reapply for a permit to use florfenicol to treat the disease, said it "remains committed to responsible antibiotic management". When asked if the salmon industry had reapplied for the future use of florfenicol in Tasmanian waters, an Australian Pesticides and Veterinary Medicines Authority spokesperson said the agency does not comment on applications. Dr John Whittington has defended the use of antibiotics by the industry. (ABC News: Monty Jacka) Salmon Tasmania chief executive John Whittington said the evidence was clear that florfenicol is an effective medication to treat P. salmonis — a disease that has devastated salmon stocks across south-east Tasmania over two consecutive summers. A salmon company gave Tasmanian authorities a week's notice before it planned to start using a new antibiotic in the state's waterways to combat a disease outbreak, sparking a strong rebuke from the industry regulator. Dr Whittington said the treatment, when used under the state's regulatory framework, does not "impact the environmental health of our waterways or safety of fish caught from them". In May, the Tasmanian Environment Protection Authority (EPA) determined the use of the antibiotic "posed a low risk of unacceptable harm to marine ecosystems". Despite that determination, the salmon industry has grappled with mass mortality events for two consecutive years. Between January and April 2025, almost 15,000 tonnes of salmon died from the disease outbreak across fish pens in south-east Tasmanian waters. The antibiotic oxytetracycline was initially used by salmon company Huon Aquaculture to treat the outbreak, but was deemed "largely ineffective". That November, the federal agency responsible for administering the medication, the APVMA, granted the industry an emergency permit to use another antibiotic, florfenicol, to treat the bacterial outbreak. It marked the first time the antibiotic, which is commonly used in land-based farming, had been approved for use in Australian waters. Dead salmon seen in fish pens in southern Tasmania in February, 2025. (Supplied: Bob Brown Foundation) Those black, circular things floating in the water off the Tasmanian coastline? They are salmon farms. Here is how many there are — and who owns them. The industry used florfenicol to battle the ongoing disease this summer, but the permit to use the antibiotic was revoked by the APVMA in March this year, following concerns it had been detected in wild fish 10 kilometres from where it had been used. In early June, the Tasmanian government confirmed it had been found up to 14 kilometres away, prompting it to directly intervene. With many domestic and overseas markets implem

Five tonnes of antibiotics used to combat disease in salmon

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