Regulator Notice – Antibiotic Treatment - Administration of Florfenicol
It is now known the bacteria Piscirickettsia salmonis or P. salmonis is endemic and has been in Tasmania's east and south east waters for some time.
P. salmonis is a marine bacterium. The bacterium causes disease in salmon. Global evidence confirms it is a major contributor to high mortality rates in salmon farming.
P. salmonis is a fish disease. It does not present a human health or food safety risk.
The Australian Pesticides and Veterinary Medicines Authority (APVMA) has recently approved salmon producers using Florfenicol. The antibiotic Florfenicol has previously been used in Tasmania in small quantities between 2007 and 2010.
Veterinary science indicates Florfenicol is effective in combating P. salmonis.
In the event that fish in marine farms require Florfenicol treatment companies must advise the Environment Protection Authority (EPA) and the Department of Natural Resources and Environment Tasmania (NRE Tas)'s Biosecurity Tasmania before the treatment is applied.
The EPA is responsible for ensuring monitoring of antibiotic residues in the environment is undertaken and to ensure that the use of antibiotics in finfish farming does not cause environmental harm.
NRE Tas is responsible for administering the Biosecurity Program: Tasmanian Salmonid Industry. It is also responsible for administering the Tasmanian Primary Produce Safety Act 2011 and the Primary Produce Safety (Seafood) Regulations 2023 which applies food safety standards and controls to the primary production and processing of seafood.
Both regulators (EPA and NRE Tas) will be undertaking a number of core monitoring and/or compliance activities in relation to the use of Florfenicol.
EPA Florfenicol Antibiotic Residue Monitoring Schedule
The EPA has developed a new Florfenicol Antibiotic Residue Monitoring Schedule that must be complied with. The Schedule has been prepared through a review of scientific literature and with support from Public Health Services.
The Schedule addresses the shorter half-life of Florfenicol and will provide data on the detection and break-down of antibiotic residues in sediments, wild fish and water.
The Schedule also requires baselines surveys to be completed before any antibiotic treatment event.
Results from this monitoring will inform future environmental and public health advice relating to the use of Florfenicol in Tasmania.
A final report for each antibiotic treatment event will be published on the EPA website when residue monitoring has been completed.
NRE Tas - Biosecurity Tasmania – Florfenicol Compliance Audit Schedule
Biosecurity Tasmania will implement a Compliance Audit Schedule to ensure Florfenicol administration by salmon producers complies with Biosecurity Program: Tasmanian Salmonid Industry Marine Operating Standards 29 and 30.
Marine Operating Standard 29 requires a salmonid producer to ensure that levels of antibiotics, or chemical residues present within or outside a marine farm derived from therapeutant use on the farm, do not exceed any levels specified in the producer's environmental licence, or in any other relevant legislative requirement or instrument issued by a Commonwealth, State or Local Government authority.
Marine Operating Standard 30 is concerned with notification requirements, ensuring correct withholding periods are met, ensuring all feed equipment used to deliver and distribute medicated feed is appropriately treated after use and requirements to undertake residue testing specified in any relevant legislative requirement or instrument issued by a Commonwealth, State or Local Government authority are complied with.
Biosecurity Tasmania will publish a summary report regarding the Compliance Audit outcomes.
NRE Tas – Food Safety Standards
- The APVMA Permit mandates if fish are treated with Florfenicol they would have to be held for at least 300 degree-days before they can be harvested for human consumption. This period allows the depletion of antibiotic residues to mitigate the risk of antibiotic residues being present in the flesh of salmon in the commercial marketplace and food service.
NRE Tas's Biosecurity Tasmania Florfenicol Compliance Audit Schedule will audit salmon companies' compliance with the requirement that all stock receiving medicated feed is recorded to ensure the correct withholding period is met.
In addition, the Australian Government Department of Agriculture, Fisheries and Forestry regulates the production and export of fish and fish products through the Export Control Act 2020 and the Export Control (Fish and Fish Products) Rules 2021. Commonwealth law requirements mandate that fish treated with antibiotics must be held for a certain period before they can be harvested for export.
NRE Tas - Marine Fisheries
Public Health
The Director of Public Health is responsible for providing human health advice on the implications of the use of Florfenicol for wild fish caught recreationally in Tasmania's marine environment.
The monitoring undertaken by the EPA will gather data on Florfenicol metabolites in wild fish which will inform future public health advice.
For the latest public health information visit the Department of Health website.
Additional Information
Piscirickettsia salmonis Information Sheet
Therapeutant use is also published on the NRE Tas Salmon Farming Data Portal.
Issued: 7 November 2025
Director, Environment Protection Authority – Catherine Murdoch
Acting Secretary, Department of Natural Resources and Environment Tasmania – Deidre Wilson
Director of Public Health – Dr Mark Veitch
Florfenicol Treatments
The APVMA has approved salmon producers using Florfenicol specifically within the south-eastern biosecurity zone.
Figure 1: The South-eastern biosecurity zone
For the purposes of setting antibiotic residue monitoring requirements the EPA has received Veterinary Authority documents as shown below:
Completed
- Tassal undertook treatment with Florfenicol at their Meads Creek (MFL 77) and Stringers Cove (MFL 209) leases commencing on 7 November 2025 for a period of 10 days.
- Huon Aquaculture undertook treatment with Florfenicol at their Zuidpool lease (MFL 141) (north lot) commencing on 12 November 2025 for a period of 10 days.
Current
Current Public Health advice: Advice for recreational fishing | Tasmanian Department of Health
Current treatment locations and the associated 3km buffer zone recommended by Public Health can be found here: LISTmap - Land Information System Tasmania
Antibiotic Residue Monitoring Requirements
The EPA has issued a schedule of monitoring requirements to each of the companies in relation to the above florfenicol treatment events. The monitoring requirements outlined in the schedules are extensive covering seabed sediments, water quality and wild fish at times before, during and after florfenicol treatment and at leases that are not receiving florfenicol treatment for comparison purposes.
The
results of these monitoring programs will be reviewed to inform future
monitoring requirements for Florfenicol.