Adapting salmon stocks to meet climate change challenges

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A $4.4 million collaboration between biologists at the University of Waterloo, Memorial University and the Universities of Guelph and Prince Edward Island in Canada, could be the key to an improved salmon stock that can survive in higher water temperatures.

Canadian scientist Brian Dixon, a biology professor at Waterloo, with expertise in fish immunology and climate adaptation, predicts that Canada’s $400 million salmon aquaculture industry could be wiped out within the next 25 years, with sea surface temperatures in the North Atlantic Ocean climbing.

“Temperatures are already approaching the upper limit. Even a rise of 2 degrees would be lethal to current salmon stocks,” says Dixon. “Canada’s salmon farming industry is going to feel the impact of climate change very soon – it’s now a race against time.”

Genetic and molecular tools

Temperatures along the Canada’s east coast are predicted to jump between 2 and 4 degrees Celsius by 2040. This leads to 25 per cent lower oxygen levels in the water, a condition known as hypoxia, as well as higher incidences of sea lice and other diseases.

Using the next generation of genetic sequencing and selective breeding techniques, the scientists wants to adapt the Atlantic salmon stock and create new genetic and molecular tools that will help other aquaculture sectors with the same problems.

The team will conduct a set of disease challenges meant to find more robust salmon families that can withstand the increased threats and stresses of higher temperatures, hypoxia, sea lice, bacterial kidney disease and amoebic gill disease. Once a stock gets infected with bacterial kidney disease, for example, it can take as long as a decade to recover.

Professor Dixon will investigate how higher temperatures affect the fish’s immune response as well as their response to vaccines, a key tool for keeping stressed fish stocks healthy. He also plans to identify the genetic markers associated with improved physiological and immunological traits that can help the fish survive higher temperatures.

Collaboration with Australian farmers

Dixon and his team also plan to explore opportunities to collaborate with Atlantic salmon farmers in Australia, who have successfully adapted stocks from New Brunswick to their higher water temperatures.

The ‘Mitigating the Impact of Climate-Related Challenges on Salmon Aquaculture’ project (MICCSA) is jointly funded by Cooke Aquaculture, Novartis, Somru BioScience and the Centre for Aquaculture Technologies.