'Alarming' 700kg antibiotic dose in D'Entrecasteaux Channel sparks contamination fears

Tasmanian salmon farms have used more antibiotics in two weeks than triple the state's entire usage last year, forcing the closure of a local rock lobster fishing. What the state’s budget estimates hearings uncovered.

Greens lkeader Rosalie Woodruff speaks to the media on Parliament Lanws in Hobart on Thursday, November 20, 2025.

Salmon companies have used around 700 kilograms of the antibiotic florfenicol at three sites in the D’Entrecasteaux Channel in the last two weeks, budget estimates committee hearings have heard.

The quantity is more than three times the total antibiotics used by the industry statewide last year.

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.

Long Bay Salmon Farms. Tasman Peninsula, Tasmania

An outbreak of the disease caused a mass mortality event last summer which killed 15,000 tonnes of fish.

The use of the antibiotic has led to the closure of the commercial rock lobster fishery in the D’Entrecasteaux Channel until further notice to protect Tasmania’s export markets from bans because of residues.

Senior manager of salmon science and standards at the Environment Protection Authority Raymond Bannister told the hearing Tasmania typically used much less antibiotics when compared with other countries.

“In terms of the quantities that are used in countries such as Canada, you’re looking at 3000 kilograms of antibiotics that are used in a year compared to compared to somewhere like Chile, for example, who uses 351 tonnes of antibiotics in the environment,” Dr Bannister said.

“Last year, we used 180 kilograms of antibiotics in Tasmania.

“If we compare to China, if you want to do another comparison to another country, they used about 10,000 tons of antibiotics last year in aquaculture.”

The hearing was told local producers have used six tonnes of antibiotics in local waters in the last decade.

Greens leader Rosalie Woodruff said the volume of antibiotics currently being used in the D’Entrecasteaux Channel was alarming.

“It is incredibly disturbing news from the EPA that some 700kg of fluorfenicol have been used at three salmon farm sites in the last 13 days,” she said.

Greens lkeader Rosalie Woodruff speaks to the media on Parliament Lanws in Hobart on Thursday, November 20, 2025.

“Seven hundred kilograms represents a bit over ten per cent of what’s been used across all salmon companies for the last six years; it’s an extraordinarily high amount of antibiotics.

“The use of florfenicol at such extremely high levels is the reason the rock lobster fishery has been shut down, and it’s the reason that recreational fishers will not be able to fish in the lead-up to Christmas because of the potential for antibiotic residues.

“This is an extreme example of salmon companies completely running public waterways on their own terms, and a failure of the Liberal government to stand up against them, to protect the marine environment, to protect other fisheries, to protect recreational fishers and the public.”

Minister for the Environment Madeleine Ogilvie reassured the public.

Minister Madeleine Ogilvie. Tasmanian house of assembly question time. Picture: Nikki Davis-Jones

“I might just add, at a personal level, as an anecdote, fish on the shelves is safe to eat,” she said.

“I’ve ordered my Christmas shopping. I’m going to get salmon, crayfish, prawns, got that ready to go, and I just want people to feel confident broadly, that our processes work, that our monitoring works, that our standards are good.”

Originally published as 'Alarming' 700kg antibiotic dose in D'Entrecasteaux Channel sparks contamination fears