Rare 4,000-year-old seaweed patch the size of 900 rugby pitches discovered in UK waters

The vast seabed of maerl, a rare and ancient seaweed, was discovered as part of a project to look at the potential of marine habitats in tackling climate change

One of the biggest ever patches of a rare seaweed has been found in UK waters – the size of 900 rugby pitches.

Researchers discovered the vast seabed of maerl, a rare and ancient seaweed, as part of a project to look at the potential of marine habitats in tackling climate change. Scientists discovered the living habitat carpeting the seafloor, which is part of the Fal and Helford Estuary Special Area of Conservation.

It is thought to be up to 4,000 years old and provides protection for many small marine plants and animals. It is also extremely efficient at storing carbon at an estimated rate of 841 tonnes or CO2 annually, the equivalent to nearly 4m petrol car miles a year and five times greater than that absorbed by the combined area of seagrass, kelp and saltmarsh also in the catchment.

Cornwall Council commissioned the University of Exeter and environmental researchers Natural Capital Solutions to carry out surveys off the coast near Falmouth and Penzance to assess how effective seagrass and seaweed are at growing and storing ‘blue carbon’. The Blue Natural Capital Project was the first time the full extent of the maerl beds and the organic matter stored in the conservat