The use of antibiotics on our farms is rare and is strictly limited to the management of isolated fish health issues. The use of antibiotics is scientifically supported and widespread. The most typically administered antibiotic (Oxytetracycline) is approved by the Australian Pesticides and Veterinary Medicines Authority (AVPMA). Treatment is administered via medicated feed and is coordinated by a qualified veterinary officer.
Visible orange signage is erected upon pens which have received treatment to notify waterway users.
All treated stock is subjected to a mandatory withdrawal period. As such, treated fish will not be harvested before the end of the mandatory withdrawal period.
If treatment is required, EPA are notified and a comprehensive Environmental Antibiotic Residue Monitoring program is undertaken at the farming lease. This monitoring program is prescribed by the EPA and is developed to comprehensively assess the specific treatment event. The program includes sediment and wild fish analysis, with samples collected at a range of distances from the lease, at various frequencies. The results are provided to the EPA and, upon completion of the monitoring program, a final report is submitted for publication.
In alignment with the 2019 GSI methodology, antibiotic use has been calculated as the number of fish that received treatment in proportion to the total number of Tassal fish produced over that same period.
Tassal intends to update the dashboard every June and December.
Following a treatment event at Okehampton in May 2023, the monitoring program identified the following key findings, which were also included in the final report submitted to the EPA:
- A wild fish sample from an ambient monitoring site returned an Oxytetracycline concentration comfortably below the Food Safety Guideline maximum residue limit (MRL) of 0.2 mg/kg. An independent review of this result determined that it was highly unlikely that Tassal was the source of the antibiotic residue, as it was approximately 7km from the treatment site.
- No fish tested within the lease boundary returned Oxytetracycline concentrations above the MRL.
- The first round of sediment analysis identified elevated concentrations of Oxytetracycline in the sediment below the treated pens. These concentrations declined rapidly and were below the MRL during the final round of sampling.