Climate change worsens disease, environmental stress in Norway’s salmon farms

Climate change is already increasing disease risks and environmental stress in Norway’s salmon farming industry, according to a new report assessing impacts through 2050.

Researchers from Norway’s Institute of Marine Research said warming seas, more frequent marine heatwaves, increased rainfall and higher runoff are changing conditions along the Norwegian coast and in fjords.

These shifts are reducing salinity and oxygen levels, creating more difficult conditions for both farmed and wild salmon.

“The overall picture points to a clear pattern,” said research manager Mari Myksvoll. “Climate change is intensifying the problems associated with fish welfare, disease, escapes and environmental impact.”

The report finds that these environmental changes are making ecosystems less resilient to the pressures of aquaculture. It warns that farmed salmon are becoming more susceptible to disease, while wild salmon face additional stress.

“These are physical and chemical changes in the environment, which make the ecosystem more vulnerable,” said research manager Ingrid Johnsen. She added that warmer seas and more heatwaves are creating “a more challenging environment for marine life.”

Researchers also note that fjords and coastal waters are under growing pressure, with climate impacts expected to intensify towards 2050. While uncertainties remain about disease dynamics and long-term ecosystem changes, the report says the direction of impact is clear.

“The big picture is unequivocal,” said Myksvoll. “Extensive climate change is affecting Norwegian coastal and fjord areas today, and the effects will only intensify towards 2050.”