Industry release first results in from florfenicol testing in Tasmanian salmon farms
Testing reveals antibiotic levels equivalent to just 20 grains of salt in an Olympic pool following controversial salmon farm treatments in Tasmanian waters.
The first results from environmental testing following the use of the antibiotic florfenicol to treat fish in salmon farms have been released by the industry.
The testing, which was designed by the Environmental Protection Authority and Public Health and conducted by third-party experts, show no detectable levels in the sea floor sediment have been found, extremely low levels in the water column on the day after the treatment and only trace levels in two of 286 wild fish caught.
Salmon Tasmania CEO John Whittington said the results confirm that florfenicol was the most effective treatment, it was safe for consumers and the best option for the environment.
“The salmon that have been treated with florfenicol are healthy, it’s the textbook response expected with this gold-standard treatment,” Dr Whittington said.
“This is great news for our salmon farmers who have been working hard to have every tool in the toolbox to try to ensure last summer’s mortality event doesn’t happen again.”
The Australian Pesticides and Veterinary Medicines Authority approved the use of the antibiotic florfenicol to treat the disease piscirickettsia salmonis in farmed salmon on November 11.
It aims to prevent mass mortality events which plagued the salmon industry last summer.
A budget estimates committee heard on November 20 that salmon companies had used 700kg of the antibiotic at three sites in the D’Entrecasteaux Channel over two weeks.
It prompted the closure of the commercial rock lobster fishery in the Channel to protect Tasmania’s export markets from bans because of residues.
Public Health Director Mark Veitch recommended people not consume fish caught within 3km of a salmon pen being treated with florfenicol – both during the treatment period and for 21 days after it ends.
Rigorous environmental monitoring has since been rolled out across leases where florfenicol is used.
This monitoring program examines the levels of florfenicol in sea floor sediment, water column, and wild fish at various distances from the lease, before treatment, during treatment and post treatment on day one, seven, 14 and 21.
The results are in for day one and day seven post treatment at the first two leases where florfenicol was used, and day one at the third lease where florfenicol was used – all near Dover.
“The results are markedly consistent across all three lease sites,” Salmon Tasmania said in a statement.
The results show:
NO detectable florfenicol in the sea floor sediment.
EXTREMELY low levels in the water column – the equivalent of 20 grains of salt in an Olympic swimming pool the day after treatment, then quickly disappearing as florfenicol breaks down rapidly in seawater.
EVERY wild fish caught was safe to eat, by Australian food standards. There was no detectable florfenicol in 286 fish, one fish recorded a negligible trace, and another recorded a trace, but was still safe to eat.
Salmon Tasmania said based on this data, an adult would have to catch and eat more than 1000 serves of fish in a week to come anywhere near the acceptable daily intake.
Given the high level of consistency of results, the data suggests that sampling of future treatments would deliver similar results that clearly demonstrate no environmental or public health concerns.
“I understand that some people are nervous about the use of antibiotics in Tasmania’s waters, that’s why I am sharing these results now that they are available,” Dr Whittington said.
“What these results show is that it is safe to catch, safe to eat and safe to swim in our waterways.”
All monitoring results are submitted to the EPA and Public Health, and will inform future public health advice.
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Originally published as Industry release first results in from florfenicol testing in Tasmanian salmon farms
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