Rare seaweed species discovered in Cornwall marine survey
Findings call for urgent protection of underwater ecosystems
Last updated 8 hours ago
Cornwall's south coast has become the site of groundbreaking marine discoveries with Natural England's latest surveys revealing rare and previously unknown seaweed species flourishing in maerl beds.
These underwater explorations uncovered a remarkable array of seaweeds, including some species previously unseen in the UK, showcasing Cornwall's marine biodiversity.
Among the discoveries are species not observed in centuries, including a newly identified tiny red seaweed, Ceramium, which marks a breakthrough for marine science.
Divers retrieved fragments of this minute pincer weed, allowing scientists to cultivate it in labs and sequence its DNA for the first time.
Natural England Senior Marine Officer Angie Gall emphasised the importance of these habitats.
“These discoveries show just how special these habitats are. We’ve already recorded more than 350 species living on the surface of the maerl beds, and that’s only the beginning," Gall said.
"Many more species live hidden within the maerl or appear at different times of year. There is still so much to uncover. Maerl beds are living archives of our natural history. Protecting them is essential if we are to safeguard marine biodiversity for future generations.”
Professor Christine Maggs, a leading authority on seaweed taxonomy, expressed her excitement over the Ceramium discovery.
“I first encountered this tiny Ceramium in the early 1980s, and I have been wondering about it ever since," Maggs said.
"It’s so minute that you can only study it if divers bring it up alive, and even then it takes careful cultivation to get enough material to work with. Natural England’s surveys finally provided the missing piece of a scientific puzzle I’ve been trying to solve for most of my career.”
The surveys additionally recorded other significant species, such as Ulva rigida (green sea lettuce), Neofolia rosea (little rosy tongue weed), and Bonnemaisonia clavata, a red seaweed not seen in British waters since the 18th century.
Seaweed expert Francis Bunker commented on the thrill of uncovering species new to science.
"Finding species new to science in our waters is thrilling. But it also shows how much biodiversity is still hidden in these beds and what we stand to lose if these habitats are damaged before we’ve fully understood them," Bunker said.
Maerl beds, characterised by slow-growing coral-like red seaweed, are among the most diverse shallow-water habitats in the northeast Atlantic. They serve vital roles, supporting marine life and playing a part in carbon sequestration.
Initial reports from citizen scientist divers led to Natural England's extensive surveys in 2023 and 2024, revealing previously unknown maerl beds off the south coast.
The discoveries underscore the vulnerability of these habitats against threats from scallop dredging, pollution, and climate change.
Protecting these valuable ecosystems is paramount, not only for the species discovered but for those yet to be identified.