A cloud of secrecy hangs over Tasmania's salmon hatcheries, sparking urgent calls for transparency regarding antibiotic use! You might be surprised to learn that when salmon get sick in freshwater environments, companies aren't always required to tell you about the treatments they use. This is precisely what happened recently with Huon Aquaculture, which confirmed using the antibiotic oxytetracycline to combat disease in its salmon at the Meadowbank hatchery on the River Derwent.
But here's where it gets controversial... While there are stricter rules for using antibiotics like florfenicol in marine fish farms, the same level of public disclosure isn't mandated for freshwater facilities. This means that details about Huon Aquaculture's antibiotic use only came to light after a report by the Tasmanian Inquirer.
Huon Aquaculture explained that they deployed oxytetracycline as a "last line of defence" when they noticed an increase in salmon mortality. This wasn't due to the same bacterial disease that caused a significant fish die-off in coastal areas last summer, but rather an intestinal infection. The company's general manager of aquaculture, Depha Miedecke, noted that a spike in water temperature in mid-January likely contributed to this issue.
Under veterinary guidance, two groups of fish were treated with the medication over a 20-day period. The Meadowbank hatchery is located about 20 kilometers upstream from New Norfolk and falls within the Hobart water catchment area. Although TasWater's Bryn Estyn water treatment plant is much further downstream, Huon Aquaculture stated they chose to be "proactive" and "transparent" by voluntarily informing the Environment Protection Authority (EPA).
Ms. Miedecke emphasized that using antibiotics in freshwater is "very rare" and not a regular occurrence for the company. The EPA confirmed that they have now implemented antibiotic residue monitoring at the Meadowbank Hatchery, a step taken following Huon Aquaculture's disclosure. The EPA also stated that these regulatory requirements will be extended to all freshwater hatcheries across the state, enhancing their oversight.
And this is the part most people miss... Oxytetracycline is a widely used antibiotic in agriculture, aquaculture, and even human medicine. The World Health Organization considers it a "highly important antimicrobial." However, the WHO also warns that "antimicrobial resistance," a consequence of the "misuse and overuse" of these drugs, is a "top global public health and development threat."
Independent MLC Meg Webb has voiced strong criticism, calling the situation a "murky lack of transparency." She argues that the public shouldn't have to depend on voluntary disclosures from salmon companies. "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," Webb stated, highlighting the importance of building public confidence and a social licence for the industry.
Interestingly, oxytetracycline was used during the coastal salmon pen die-off last year, but Huon Aquaculture found it to be "largely ineffective." In contrast, a different antibiotic, florfenicol, was approved for use in southeastern waters in November and is now applied in pens in the D'Entrecasteaux Channel and off Bruny Island. The salmon companies provide "real-time updates" on their websites detailing when and where florfenicol is used. A comprehensive monitoring system is in place for this drug, including testing of water and wild fish. The director of public health, Mark Veitch, previously advised the public to avoid consuming fish caught within three kilometers for 21 days if they wished to avoid antibiotic residue. The industry had previously argued that florfenicol offered advantages over oxytetracycline due to lower required dosages, reduced excretion by fish, and lower toxicity to aquatic life.
The Greens have urged the government to make real-time disclosures mandatory for all antibiotic use in Tasmanian waters. Greens MP Tabatha Badger called for immediate action from the Liberal Government to report antibiotic use in real-time and to reduce stocking on diseased salmon farms. However, Health Minister Bridget Archer stated that antibiotic use in Tasmania's agricultural and aquacultural industries is "heavily regulated" and expressed no concerns about public health risks.
What do you think? Should the public have immediate access to information about antibiotic use in all salmon farming environments, or are the current regulations sufficient? Let us know your thoughts in the comments below!
