How climate change threat is being tackled by Scotland's salmon farmers

Compared to 2023, when some coastal waters around the UK saw temperatures four to five degrees warmer than average, 2024 has been the polar opposite. The El Niño weather patterns are widely accepted as contributing to that phenomenon, but forecasters predict that this period is now past – and temperatures have reduced in line with normal trends.

Seawater temperatures are not a direct problem for the salmon being raised on Scotland’s coastal west strip and around the islands; they thrive within a range. Fish are cold-blooded, so higher seawater temperatures actually encourage growth and allows the harvest weight to be reached more quickly.

Algal blooms and micro-jellyfish

However, warmer seas also mean an increase in plankton, algal blooms and micro-jellyfish –marine species that can harm salmon. Fish farmers – like all farmers – want as many of their animals to make it to market, even more so when Scottish salmon has never been in more demand.

So this year has, therefore, seen a very welcome and significant increase in survival rates at Scotland’s salmon farms. In fact, the most recent published figures for August 2024 show the best survival rates in five years.

The percentage of fallen stock was less than half the same month the year before, and the lowest level of monthly mortality since August 2019. It is testament to the hard work of the men and women, the vets and the farm assistants, working in our sector that we seem to have turned a corner.

But we know that climate change will continue to pose a significant challenge to all forms of food production – on land and at sea. We can’t simply stand back and hope that normal seawater temperatures continue in the years ahead.

Curtains made of air

That’s why salmon farming companies are investing in innovation, research and development, something which Scotland has a long, proud history of pioneering. We have been farming in the seas around Scotland for half a century, and the knowledge and experience we have built up over that time will help us thrive into the future.

I am often asked what is the solution to the challenges posed by climate change? Salmon farmers now have an increasing number of tools at their fingertips to provide the best growing conditions for fish.

These include aeration and oxygenation of seawater added to feeding techniques that reduce the time salmon spend near the water’s surface. Other innovations such as bubble curtains use air to create a barrier which prevents contact with organisms that are harmful to our fish.

And several farming companies are also developing initiatives that will see larger fish put to sea, reducing the amount of time salmon spend in the elements.

With its low carbon footprint, Scottish salmon is exactly the sort of food the world needs. And through the very best in Scottish innovation, research and development, we can overcome the challenge of climate change.

Tavish Scott is chief executive of Salmon Scotland, the trade body for the salmon farming sector