BRIDGWATER Bay stores significant amounts of organic carbon, according to estimates in a series of new scientific reports.

The Blue Carbon Mapping Project was completed by the Scottish Association for Marine Science on behalf of the WWF, The Wildlife Trusts and the RSPB. It found that 244 million tonnes of organic carbon are stored in the top 10cm of UK seabed sediments, with 98% stored in seabed sediments such as mud and silt.

Bridgwater Bay, which is well-known for its muddy estuary that stretches from Minehead, along to Bridgwater, Burnham-on-Sea, and Brean Down, was found to store significant amounts of organic carbon. The reports estimate that the 48km2 Site of Special Scientific Interest (SSSI) accumulates a significant 3.076 kilotons of organic carbon each year. In addition, it was found to have an organic carbon density of 0.579 km/m2

The reports also recognised that the “highest organic carbon density is found in the upper Bristol Channel”. Carbon is primarily absorbed by phytoplankton, which drift to the bottom of the sea when they die and are added to seabed sediment. The research analysed the storage capacity of just the top 10cm of sediment, meaning the total amount of ‘blue carbon’ stored will be far greater.

Tom Brook, blue carbon specialist at WWF-UK, said: “This project reveals how critical our seas are in regulating the climate and underscores the urgent need to protect and restore our seabed habitats. While saltmarshes and kelp forests punch above their weight in terms of capturing carbon, the mud really is the star here – accumulating and storing vast amounts on the seabed. But we need to make sure it goes undisturbed for it to fulfil this critical function. Harmful activities such as bottom trawling must be stopped.”

Director of marine policy for The Wildlife Trusts, Joan Edwards, commented: “These world-first reports reveal the enormous value of UK seas, while highlighting that many areas need far better protection.”

She added: “We need strategic decision-making from policymakers to recognise the value of blue carbon by minimising the impact of human activities on the seabed. Damaging activities such as bottom trawling and large development must not take place in protected areas. This research gives the UK an opportunity to lead the world in protecting blue carbon and marine biodiversity."