Huon Aquaculture's Antibiotic Use at Freshwater Hatchery Prompts Calls for Greater Transparency

Huon Aquaculture recently used the antibiotic oxytetracycline at its Meadowbank freshwater hatchery in Tasmania to treat diseased salmon, prompting calls for increased public disclosure regarding antibiotic use in such facilities. There are currently no mandatory disclosure requirements for antibiotic use in freshwater hatcheries, in contrast to stricter regulations for florfenicol in coastal marine fish farms.

There are currently no mandatory disclosure requirements for antibiotic use in freshwater hatcheries, in contrast to stricter regulations for florfenicol in coastal marine fish farms.

Details of the Treatment and Voluntary Disclosure

Details of Huon Aquaculture's antibiotic use, approximately 40 kilometers upstream from the Bryn Estyn water treatment plant, became public following a report by the Tasmanian Inquirer. The company stated the antibiotics were deployed as a 'last line of defence' due to an increase in fish mortality caused by an intestinal bacterial infection, which occurred after a spike in water temperature in mid-January. This infection was distinct from the bacterial disease responsible for mass salmon die-offs in coastal waterways last summer.

Company General Manager of Aquaculture, Depha Miedecke, confirmed the medication was administered to two cohorts of fish over a 20-day period under veterinary guidance. Despite no regulatory obligation, Huon Aquaculture made a voluntary disclosure to the Environment Protection Authority (EPA).

EPA Implements New Monitoring Requirements

In response to the disclosure, the EPA has implemented antibiotic residue monitoring at Meadowbank Hatchery. The EPA stated that these new regulatory requirements, including monitoring, will be applied across all freshwater hatcheries in Tasmania, strengthening the existing framework. Monitoring results are expected to be published on the EPA website.

Calls for Transparency and Regulatory Debate

Independent Member of the Legislative Council (MLC) Meg Webb criticized the 'murky lack of transparency' surrounding antibiotic use in salmon farms, arguing that the public should not depend on voluntary disclosures and advocating for full transparency. The World Health Organization (WHO) classifies oxytetracycline as a 'highly important antimicrobial' and has raised concerns about antimicrobial resistance resulting from misuse and overuse.

The World Health Organization (WHO) classifies oxytetracycline as a 'highly important antimicrobial' and has raised concerns about antimicrobial resistance resulting from misuse and overuse.

The Greens called for the government to mandate real-time disclosures for all antibiotic use in Tasmanian waters and suggested destocking diseased salmon farms. However, Health Minister Bridget Archer affirmed that antibiotic use in Tasmania's agricultural and aquacultural industries is 'heavily regulated' and expressed no concerns about public health risks associated with the practice.

Contrasting Regulations: Freshwater vs. Coastal Farms

For coastal marine farms, 'real-time updates' on florfenicol use are available on salmon companies' websites, accompanied by a monitoring system. Florfenicol was approved for use in November as an alternative to oxytetracycline, which Huon Aquaculture previously found 'largely ineffective' during a mass mortality event.