Yet Another Rickettsia Outbreak in the Huon River-D’Entrecasteaux Channel - updated, keep reading

It was revealed on ABC radio 15 August 2025 that Huon Aquaculture's salmon lease at Roaring Beach, south of Hobart, is infected with the deadly Rickettsia disease, and there are reports that the usual antibiotics are not effective. This follows massed salmon deaths last summer, resulting in oily balls of rotting salmon flesh washing up, first at Verona Sands, then at other beaches in the Channel and lower Huon River.

This alarming news has not yet been confirmed by government or industry. As at 3pm 15 August there did not appear to be anything on the websites of the EPA or Biosecurity Tasmania. Last February the government was very slow to act, which confirms doubts raised about the ability of the EPA and Biosecurity Tasmania to deal effectively with issues of public health and amenity.

Updated 6pm - read the Greens press release below!

Antibiotics are not reliably effective against Riksettia (piscirickettsiosis) outbreaks due to in part to antibiotic resistance. Experience overseas shows that reducing stock densities is an essential part of effective disease control.

Piscirickettsiosis can survive in seawater for up to 21 days, and the best temperature range for it is much the same as that for salmon. It infects host animals orally or by breaching the skin or gills. Symptoms include lesions, ulcers, and darkening of the skin, abdominal swelling, and anemia. Lethargy, loss of appetite, respiratory distress, and surface swimming have also been observed. Mortality rates in pens are often around 35% but can reach 90%.

Riksettia is a fish pathogen and does not cause disease in people, however government advice issued last March is to not handle or consume the dead fish material, avoid activities that will bring you into contact with the material, and wash your hands with soap and water if you do.

• Listen to the ABC local radio interview – riksettia comes in at 7 minutes 53 seconds.

The Greens Media Release (and lots more information) added 6pm 15 August

Huon Aquaculture Calls the Shots While Government Agencies Left Guessing
15 August 2025News that a significant Piscirickettsia salmonis outbreak is occurring in Huon Aquaculture's pens in the middle of winter is shocking, and more evidence of a marine environment in deep distress. It is more important than ever the Liberal and Labor parties recognise the need for stronger environment laws to rein in salmon corporations.

In an unprecedented move, the Liberal government, in caretaker-mode, has processed a fast-track application to the APVMA to approve an unregistered antibiotic for use by the salmon industry.

The Greens and crossbench MPs were invited to a multi-agency briefing after news from the Premier that a disease outbreak is occurring at Huon pens off Roaring Beach. In the farcical meeting, it took one and a half hours for MPs to get confirmation that a disease outbreak is, in fact, occurring.

Despite there being representatives from multiple agencies and industry on hand, none could clarify how substantial the outbreak is, and what is the "emergency" that justifies the government's fast-track antibiotic application for florfenicol. They explicitly confirmed the current marine regulations do not require salmon companies to provide the full transparency needed for effective government protection of the environment.

Once again, it's the multinational salmon companies whose tail is wagging the dog.The report into last summer's disastrous mass salmon mortality event is still six weeks away. The Minister for Primary Industries Gavin Pearce has confirmed this summer is expected to be more of the same with higher water temperatures and P. salmonis now endemic in southern waters.But we can't have more of the same. The Greens have articulated very clearly a pathway to fix this industry with our ten-point salmon plan.

The Deputy Chief Veterinary Officer confirmed their advice to the Department was to medicate fish in the hope they will survive the disease this summer. We are deeply concerned at the potential environmental and human health impacts of the use of this antibiotic.

Florfenicol has known and unknown effects on wild fish and humans, including reproductive, renal, immune and developmental toxicity. But, we don't know anything specific about how it will effect the Tasmanian marine environment - it is appalling the government is processing this application in haste.With marine heatwaves the new normal, salmon companies must reduce stock, fallow pens, reduce stocking densities – and have an immediate moratorium on any expansion of this industry – amongst many other management strategies.

Now is the time for the Liberal and Labor parties to commit to real and lasting measures that will protect our marine environment. The Greens expect marine protection outcomes to be explicitly stated before we return to parliament next week.