To help combat this crisis the Tasmanian salmon industry is pushing for fast approval of a new antibiotic, Florfenicol. This move coincides with the newly endemic, fish-killing bacteria P. salmonis now rampaging through salmon pens across southern Tasmania. This request follows a historic, summer mass mortality event due to bacteria. This goes to show that with the right leadership, private industry and government are actively looking for ways to stop the bleeding.
Primary Industries Minister Gavin Pearce said he was keen to cut the approval time for Florfenicol. This promising development will need new regulatory approvals. Since February, guidance shared by the government has led to some confusing messaging, which the industry has consistently communicated. They are demanding immediate action to address the chronic health emergency facing farmed salmon.
Ongoing Impact of P. salmonis
P. salmonis is an endemic, bacterial pathogen that infects salmon, leading to recurring health problems during different seasons. Deborah McSweyn, Acting Chief Veterinary Officer, noted that though the bacteria is ubiquitous, it affects fish differently.
“P. salmonis will always be there as an endemic bacteria. There is no way of being clear of P. salmonis,” – Deborah McSweyn
As in the recent historic outbreak, high mortality rates resulted among farmed salmon. Treatment had long relied on oxytetracycline antibiotics, but Pearce said they had “very limited uses.” He stressed the need for better therapeutic approaches as our scientific understanding increases.
“In my humble opinion, science continues to evolve every day,” – Gavin Pearce
The Tasmanian regulations mandate that you report every single mortality event. This is only triggered if, over a three day period, more than 0.25 percent of the fish in a pen are dead. Critics of this threshold estimate that thousands of affected fish go uncounted.
Peter George, director of the independent wild salmon fund, spoke on his observations regarding the lack of transparency in the salmon farming industry.
“What was made less clear today is exactly the extent of the disease outbreak, and that’s because the … multinational fish farms do not have to tell anyone about the extent of the disease,” – Peter George
Regulatory Considerations for Florfenicol
We are going to use Florfenicol as a top coat feed to salmon. This closed drip system has the potential to introduce the antibiotic into the wider marine ecosystem. McSweyn said he understood those risks. He further suggested that they would institute strict testing procedures to track environmental impacts, working with the Environmental Protection Authority (EPA).
“That is why we collaborate with the EPA to do really robust and very rigorous testing to monitor those effects,” – Deborah McSweyn
The approval of Florfenicol is a paradigm shift for the industry. It prevents the most needless losses and contributes to the sustainability of fish. Addressing fish health, Salmon Tasmania has once again reiterated its commitment to boosting fish health via better vaccines, tighter biosecurity, and innovations on-farm.
“New actions include improved vaccines, stronger biosecurity, feed adjustments, on-farm innovations, and new treatment options,” – Salmon Tasmania
Industry Commitment to Transparency and Welfare
The salmon industry claims to be committed to the welfare of fish, the environmental, and still providing for local communities. There is a continued demand for greater transparency when it comes to disease reporting standards and fish health management practices.
McSweyn noted how sudden P. salmonis outbreaks often are. He further underscored the heavy risks associated with trying to control their effects on fish populations.
“There is absolutely every chance that it will spread beyond the pens,” – Deborah McSweyn
Even with these challenges, Pearce is positive about the current trajectory of antibiotic use in aquaculture. Reflecting on advancements in medical treatment over the past decade, he noted that many medications are no longer prescribed today due to evolving scientific understanding.
“If I took you back 10 years, most of the antibiotics [and] medication that you would have been prescribed 10 years ago is no longer available,” – Gavin Pearce
