Climate change is affecting Scotland’s lochs and reservoirs, research shows


Climate change has already caused a rapid and extensive warming of Scotland’s lochs and reservoirs with impacts expected to intensify, research has revealed for the first time.

A report by Scotland’s Centre of Expertise for Waters shows that 97% of monitored Scottish lochs and reservoirs have increased in temperature between 2015 and 2019.

While most warmed by up to 1.0°C per year over this period, 9% increased by more than that – some by up to 1.3°C per year.

Environment Minister Mairi McAllan commented: “This important research provides yet more worrying evidence of the risks of harm from climate change on Scotland’s water environment.

“It is vital that we do more to mitigate those impacts, to seek to reduce the pace of warming but also to adapt to it. We have committed £243 million since 2015 through the Agri-Environment Climate Scheme to support land management practices which protect and enhance Scotland’s natural heritage, improve water quality, manage flood risk and mitigate and adapt to climate change.

“Scotland is renowned worldwide for the quality of our water. Research like this will be hugely valuable in informing the development of policy solutions and measures to mitigate and adapt to climate change, and also protect, restore and enhance these vital natural assets.”

Researchers warn that these changes increase the risk of harmful algal blooms developing, which could restrict their use for recreation and water supply, and as a safe habitat for wildlife.

It is expected that waters in the south and east of Scotland will warm the most at first, but this climate-related impact will reach all parts of the country by 2040.

The report makes several recommendations to address these impacts in the immediate term, as well as further research to improve understanding of climate impacts on the complex functioning of lochs and reservoirs, including reducing the amount of phosphorus and nitrogen entering lochs and reservoirs from their catchments, as these are the main driver of algal blooms.

Funded by the Scottish Government, Scotland’s Centre of Expertise for Waters (CREW) is a partnership between the James Hutton Institute and Scottish higher education and research institutes.

More information about the findings of the report is available on the CREW website.