A NEW study has found that the types of animals and plants found on Scottish rocky shores are changing due to climate change.
An increased temperature in Scotland’s seas over the last decade shows that biodiversity is changing to species that favour warmer waters, a new study by NatureScot discovered.
The report studied over 50 species at 167 locations around Scotland’s coasts.
They found clear evidence of a change of wildlife over the last decades in rocky shores species.
The shift towards warm-water biodiversity was reflected by a 0.14°C rise in the average temperature preference of the species, coinciding with a 0.20°C increase in the average sea temperature around Scotland.
“Scotland’s rocky shores are beautiful, often dramatic, environments teeming with life. Our rocky coasts also provide food for many of our birds and animals – as well as ourselves – and help protect our coasts from storms and waves. This study highlights that these habitats are already starting to feel the effects of climate change,” said NatureScot’s Dr Kelly James.
To humans, the temperature change may seem negligible, but it has a direct impact on species and the natural world.
The report shows that species such as the purple topshell, a warm-water species are flourishing due to the increase in sea water temperature.
However, cold-water species are experiencing mixed fortunes such as beanweed, declining, while others, including cold-water barnacles, increasing in number.
The study explained that overall, the slightest temperature increase has already resulted in a small shift in dominance towards warm water species.
James explained that more monitoring is needed to “understand these climate impacts” following the two exceptionally warm years of 2023 and 2024.
“More work is also needed to better understand what these changes to rocky shore communities mean for us, and the other species that depend on them. Removing human pressures from rocky shore communities will allow these communities to respond naturally to climate change.
“It is also essential that we reduce emissions and continue the many projects underway, through the Nature Restoration Fund and others, that aim to restore our natural environment, keeping these iconic seascapes safe for future generations.”
A decline in one species can affect other
One of the key findings of the study reveals the ongoing decline of a mussel species, which birds like oystercatchers, otters, and starfish rely on for food. The intertidal blue mussel, which inhabits rocky shores, has seen a decrease in numbers along Scotland's coasts, especially in the southwestern and southeastern regions.
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.
“Knowing how fast and how much our seashore life is changing tells us a lot about how our seas will continue to support the biodiversity and food we rely on for our continued health and economic prosperity, as well as helping us to better protect the natural world.”
