Seafood divers bid to block Tasmanian salmon sector's antibiotic use
The Tasmanian Rock Lobster Council, Tasmanian Abalone Council and Tasmanian Commercial Divers Association have opposed the salmon farming sector’s application to a new licence to use the antibiotic florfenicol, reports website Tasmaniancountry.com.
Salmon farmers used florfenicol over the Australian summer to prevent mass salmon die-offs from salmon rickettsial septicaemia (SRS), a disease caused by the bacterium Piscirickettsia salmonis.
But in March the Australian Pesticides and Veterinary Medicines Authority revoked the Tasmanian salmon industry’s permit to use florfenicol. Now the industry is applying to to use the antibiotic again.
Risk to wild-caught seafood
In a joint statement, the rock lobster, abalone and divers associations said: “The use of florfenicol in Tasmania’s marine environment creates a material trade risk to wild-caught seafood products in both domestic and international markets.
“This is driven by the absence of an approved maximum residue limit for wild-catch species in most markets, and in turn the application of a zero-tolerance approach to residue detections.
“As a result, even low-level detections of florfenicol in wild-caught seafood have the potential to disrupt market access, damage customer confidence, create regulatory uncertainty, and negatively impact the reputation of Tasmania’s premium wild seafood products.”
In its June newsletter, the Abalone Council – which represents harvesters of wild abalone – said: “Our position is clear. We do not believe therapeutic substances such as florfenicol should be used in our waterways, and together with other wild catch sectors we have made our position abundantly clear to the authorities, including the State Minister and his government. Discussions are continuing.”
Animal welfare
Salmon Tasmania chief executive John Whittington said the use of florfenicol was about animal welfare.
“The use of medication is an important part of that responsibility and treatments are only administered under strict veterinary supervision,” he said.
“Its use is supported by a substantial body of scientific evidence and environmental monitoring.”
Whittington told Tasmanian Country that florfenicol was an effective treatment for SRS and does not impact the environmental health of Tasmania’s waterways or the safety of fish caught from them.
0.4 parts per billion
In May, Tasmania’s Environment Protection Agency (EPA) said that out of 4,240 results from water and sediment samples collected both inside and outside nine treated fish farm sites, fewer than 12% had any measurable amount of florfenicol or its breakdown product florfenicol amine.
None of the 4,240 sample results showed florfenicol levels above the EPA's interim Default Guideline Values (DGV) level of 7 µg per litre (7 parts per billion) for florfenicol in pristine Tasmanian marine ecosystems, and 50 µg/L for florfenicol in modified Tasmanian marine ecosystems, such as the D'Entrecasteaux Channel that houses salmon farms.
Of the 171 water samples where florfenicol was detected, the highest level found was 5.2 µg/L (or 5.2 parts per billion). This sample was collected during florfenicol treatment, right next to a fish pen. The highest result was approximately 10 times lower than the EPA’s interim DGV, and the average level (0.4 µg/L, or 0.4 parts per billion) was approximately 125 times lower.
