Why did millions of salmon die in Tasmania in 2025?

Over 4 million salmon died prematurely in Tasmanian fish farms in 2025, with warming ocean temperatures approaching 18C identified as a significant factor.

What is the impact of ocean temperatures on Atlantic salmon?

Atlantic salmon are adversely affected when ocean temperatures approach 18C, leading to less oxygenated water, liver and kidney damage, reduced appetite, and increased susceptibility to disease.

Are companies being fined for the mass salmon deaths in Tasmania?

While calls are mounting to fine companies under Tasmania's Animal Welfare Act, similar to penalties in Norway, no apparent regulatory action or fines have been reported in relation to the mass salmon deaths.

Home / Environment / Tasmania's Salmon Crisis: Millions Dead, Calls for Fines

Tasmania's Salmon Crisis: Millions Dead, Calls for Fines

26 Jan

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Summary

Over 4 million salmon died prematurely in Tasmanian farms in 2025.
Warming ocean temperatures are cited as a primary cause for fish deaths.
Calls are mounting to fine companies under animal welfare legislation.

Tasmania's Salmon Crisis: Millions Dead, Calls for Fines

In 2025, Tasmanian fish farms reported the premature deaths of at least 4 million salmon, with recent data highlighting approximately 500,000 fish deaths in November and December as ocean temperatures climbed. Scientific studies confirm Atlantic salmon suffer adverse effects as ocean temperatures near 18C, leading to reduced oxygen and increased vulnerability to disease.

The last three months of 2025 saw over 2,500 tonnes of salmon perish, contributing to an annual loss of 20,133 tonnes. December alone experienced daily losses of over 40 tonnes, significantly higher than previous months. Retired professor Stewart Frusher noted that southeastern Tasmania's waters are becoming unsuitable for salmon farming.