Antibiotic name and dosing period(s)
Florfenicol 100% Active. Ten-day treatment, starting 7 November until 16 November 2025.
Summary of sampling rounds undertaken
Water, seabed sediment and wild fish samples were collected before, during and after treatment (baseline, mid-treatment, day 1 post-treatment, day 7 post-treatment, day 14 post-treatment, day 21 post-treatment, and day 38 post-treatment).
Samples were collected at sites both inside the leases (pen bays and centroids) and outside the leases, including compliance sites, transect sites, control sites (i.e. at an untreated lease) and reference sites.
In total, 100 pooled samples of wild fish, consisting of 3 individual fish per pooled sample, were caught across 3 zones (500, 1,000 and 3,000 m) from the lease boundaries. The 300 wild fish sampled included a mix of Australian salmon, flathead and wrasse.
In total, 225 sediment samples and 60 water samples were collected at multiple distances from the pen bays and including reference sites up to 7,150 m from the nearest lease boundary.
Assessment of compliance against the schedule issued by the EPA
The report is compliant with most of the requirements of the Therapeutant Residue Monitoring Schedule – Marine Farming Lease Nos. 77 (Meads Creek) and 209 (Stringers Cove) and section 28(2) of the Environmental Standards for Tasmanian Marine Finfish Farming 2023.
One minor non-compliance was identified during the mid-treatment wild fish sampling, with slightly below the required number of fish being collected. This issue was addressed promptly, and compliance was achieved for all other wild fish sampling events. This minor non-compliance did not affect the overall results of the monitoring program.
Summary of findings in report
The results outlined in this report align with the EPA's Preliminary analysis of environmental samples for florfenicol in southern Tasmania with negligible detections of florfenicol in seabed sediments and rapid depletion of the low level detections in the water column in the days after treatment.
EPA's assessment of potential environmental impacts
The EPA is currently reviewing all the monitoring data that continues to accumulate in relation to the use of florfenicol at Tasmanian salmon farms. The EPA is also awaiting completion of an external peer review of the EPA's work to establish a guideline value for ecotoxicity of florfenicol in aquatic environments. Results will be released in due course.
Statement from the Director of Public Health
Public Health Services has noted the previous reports of florfenicol residue detected in 2 wild Australian salmon samples, caught within 1 km of these leases on the day after treatment ended. Further testing of wild finfish, up to 3 km from these leases and 38 days after treatment, has not detected florfenicol residue. Eating typical amounts of these wild finfish does not pose a risk to health. Public Health Services has reviewed all results to date and maintains its precautionary advice. This advice is available on the Department of Health website.
Link to final report:
Final Report - Therapeutant Residue Monitoring Program - MFL 77 Meads Creek and MFL 209 Stringers Cove (PDF 3Mb)