Latest mass mortality data shows time has run out for salmon farming in Tasmania

500,000 prematurely dead salmon in three months show Tasmania's salmon industry is unable to operate ethically and sustainably.

New figures from Tasmania's Environment Protection Agency reveal more than 2,500 tonnes of farmed salmon (over half a million fish) died in the last three months of 2025.

Overall, at least four million salmon died prematurely in fish farms last year, statistics that confirm what coastal communities have been warning for years: Tasmania's salmon industry is pushing ecosystems, animals and regulators beyond breaking point.

The latest data, released just before the Australia Day long weekend on Friday, shows that more than 2,500 tonnes of fish died in the last quarter of 2025. The total death toll of salmon dying prematurely was 20,133 tonnes.

As ocean temperatures – already at record highs – warmed in December, and the industry released tonnes of antibiotics into waterways, more than 40 tonnes of salmon died prematurely per day on average, almost triple the monthly average through winter.

These unprecedented deaths are not an anomaly. They are the predictable outcome of warming waters, overstocked pens, and marine environments being exploited beyond capacity by the continuing onslaught of fish waste and antibiotics.

This is no longer a bad season — it's the business model.

"These are shocking figures, and they're only the beginning," said Lilly Henley, Neighbours of Fish Farming's Campaigner.

"If 2,500 tonnes died in the last quarter of 2025, it's not unreasonable to expect double or triple that next quarter as waters continue to warm. Anyone pretending otherwise is not being honest with the Tasmanian public."

• Atlantic salmon are cold-water fish who in their natural environment spend almost their entire adult lives in North Atlantic waters between 2-12 degrees centigrade.
  

• Atlantic salmon require water below 20°C to function normally, above this, they must actively seek refuge, something farmed salmon cannot do.
  

• Ocean warming makes these impacts more frequent and longer-lasting.
  

• No amount of spin, 'innovation' or antibiotic use will change the biological reality that an Atlantic salmon cannot survive long-term in waters above 20°C.
  

These limits are not debated in science, it's pure biology.

Industry body Salmon Tasmania and the Tasmanian Government must have the foresight to see that mass deaths are only going to get worse.

NOFF respects the scientists tasked with monitoring and responding to incidents. But monitoring alone is not enough. Without enforcement, transparency and real consequences, regulation becomes theatre.

"There needs to be absolute transparency around the EPA's investigation, and there must be fines for the companies responsible," Henley said.

"Mass mortalities are now being treated as an inevitable part of doing business. That should alarm every Tasmanian."

NOFF are demanding immediate public release of the EPA's investigation findings, financial penalties for companies responsible for last year's mass mortalities and a serious reckoning with the incompatibility of industrial salmon farming and a warming Tasmanian ocean.

"This industry has been warned for years," Henley said. "The science is clear. The communities are watching. Salmon are dying in the thousands of tonnes. What we're seeing now is not sustainable, not ethical, and not acceptable."

Media contact - Lilly Henley, 0429 084 434