Study finds rocky seashore species in Scotland affected by climate change - NatureScot
An increase in the temperature of Scotland’s seas over the last decade has been found to be changing the types of animals and plants found on rocky shores in Scotland to those that favour warmer waters, according to a NatureScot study published today [22 January 2025].
The report investigated changes in over 50 species at 167 locations around Scotland’s coasts over the last decade. The study found clear evidence of warming in rocky shore communities. The shift towards warm-water species was shown by an increase of 0.14 degrees Celsius in the average temperature preference of the community, at the same time as a small increase in average sea temperature around Scotland of 0.20 degrees Celsius was recorded. While these temperature rises may seem small, they translate into significant changes in the natural world, highlighting that climate change is already having an effect on Scotland’s rocky coasts.
The report revealed that some warm-water species are flourishing, such as the purple topshell, particularly on the west coast of the country. Cold-water species, on the other hand, are experiencing mixed fortunes with some, such as beanweed, declining, while others, including cold-water barnacles, increasing in number. Overall, however, the modest temperature increase has already resulted in a small shift in dominance towards warm water species.
A major finding in the study is the continued ongoing decline of intertidal blue mussels on rocky shores. Blue mussels are a characteristic species of Scotland’s rocky shores and are an essential source of food for species such as otters, oystercatchers and starfish. The mollusc decreased in number across Scotland’s rocky shores, particularly along the southwestern and southeastern coasts. Healthy populations were only found on exposed outer coasts, such as those on Orkney and Shetland. This corresponds with another ongoing study that has found declines in blue mussel beds on muddy sediments around Scotland. While the exact causes of the blue mussel decline remain unclear, factors like marine heatwaves and ocean acidification, both influenced by climate change, are possibly contributing.
Posted On: 22/01/2025
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