Climate change-resistant British coral expected

Pink sea fan. Credit: Jamie Stevens

New research shows that climate change could help a well-known coral species that lives in the waters of the UK spread out.

The pink sea fan is a soft coral that lives in shallow water from the western Mediterranean (southern range) to north-west Ireland and the south-west of England and Wales (northern range).

The species is called “vulnerable” all over the world, and the NERC Act of 2006 lists it as a species of principal importance in England and Wales.

As global temperatures rise, the new study from the University of Exeter found that the species is likely to move north, even to the coast of Britain.

The results could be used to find the most important places to protect populations of pink sea fans.

“We made models to predict where pink sea fans will live in the Bay of Biscay, the British Isles, and southern Norway in the next 2081 to 2100,” said Dr. Tom Jenkins from the University of Exeter.

“The model’s predictions showed that there are still places where the pink sea fan could live beyond its current northern range limits, in places where colonies have not yet been seen.

“I don’t know why pink sea fans haven’t moved into these places yet. Possible problems are that their larvae don’t move around enough and that there is a lot of competition between species for space and resources.

“Using a high-emissions global warming scenario called RCP 8.5, we were able to predict that pink sea fans would have more places to live to the north of their current range. This means that the species could move north by 2100.

Sea fans in pink. Author: C. Webb

“We also found that the current habitat for this species in south-west Britain, the Channel Islands, and north-west France is likely to be good for the next 60–80 years.”

The study looked at a species of soft coral called “dead man’s fingers.”

For this species, future predictions showed that the amount of good habitat in the southern part of the study area would go down, while the amount of good habitat in the northern part of the species’ range would go up.

Many species of octocoral, like pink sea fans, are important to the environment because they add complexity to reef systems and help keep marine life alive, especially when they grow in dense “forests.”

They can also be used as a general sign of the health of an ecosystem because colonies that are broken up or sick may be a sign that the environment is getting worse.

Dr. Jamie Stevens, also from the University of Exeter, said, “This research shows how complex the effects of climate change are on marine ecosystems. For example, some species’ ranges shift toward the poles when the temperature rises.”

“In a mosaic of habitats that change quickly, some species, usually those that like warmer conditions, may be short-term “winners.”

“It remains to be seen how long these species can continue to grow and thrive in the face of faster warming.”

The title of the paper, which was published in the journal PeerJ, is “Predicting habitat suitability and range shifts under projected climate change for two octocorals in the northeast Atlantic.”

Further information: Tom L. Jenkins et al, Predicting habitat suitability and range shifts under projected climate change for two octocorals in the north-east Atlantic, PeerJ (2022). DOI: 10.7717/peerj.13509

Journal information: PeerJ

Source: University of Exeter