UK seas need better protections to help tackle the nature and climate emergency 

The seas around the UK and Isle of Man cover nearly 885,000 square kilometres – over three times the size of the UK’s land mass. This vast area is host to different habitats that capture and store carbon, known as blue carbon. These habitats include seabed sediments (made of mud, silt and sand), and vegetated coastal habitats such as seagrass meadows, saltmarshes and kelp forests.   

Climate change is driven by the amount of carbon dioxide in the atmosphere. Since the start of the industrial revolution, the amount of carbon dioxide in the atmosphere has risen by about 50%, with 2023 declared the warmest year on record globally.   

So, to tackle climate change, we need to tackle carbon dioxide levels. When healthy, our seabed habitats lock away blue carbon, keeping carbon dioxide out of the atmosphere. But if these habitats are disturbed, they can release carbon into the atmosphere, potentially exacerbating climate change.   

The Blue Carbon Mapping Project set out to map and estimate the amount of carbon stored in the UK’s seabed habitats, including in Marine Protected Areas. It’s a landmark study, with the UK being the first-ever nation to do this. And the findings are startling. UK seas store an estimated 244 million tonnes of organic carbon in just the top 10cm of seabed sediments and vegetated habitats.

But the report also reveals the threats facing these vast stores of blue carbon. Disturbance to the seabed, including from bottom trawling and offshore development, are identified as threats to blue carbon stores, which is why nature charities are calling for stronger protections for UK seas.   

Together with WWF and The Wildlife Trusts, we are calling on governments across the UK to strengthen protections for valuable blue carbon stores. This includes minimising the impacts of activities at sea, such as fishing and offshore development.   

We are also calling for all Marine Protected Areas to be protected from activities that damage important blue carbon stores and threaten marine life. Doing so could help the UK to meet both climate and biodiversity goals, including net-zero and the international agreement to protect 30% of seas by 2030.  

Kirsten Carter, Head of UK Marine Policy at the RSPB, explains: “Accelerating efforts on land to tackle the nature and climate emergency is critical, but we must not underestimate the role of UK seas. This report is a gamechanger for our knowledge of the marine environment and a huge asset for decision-makers. Now we need them to act on its findings.   

“To meet net zero and stop biodiversity decline we must work with nature, not against it. This means restoring habitats, properly planning offshore development, and investing in protected areas to safeguard wildlife and keep blue carbon locked up.”   

The Blue Carbon Mapping Project, was completed by the Scottish Association for Marine Science on behalf of WWF, The Wildlife Trusts and the RSPB, and is the first comprehensive estimate of carbon captured and stored across UK seas, including within Marine Protected Areas.  

The Blue Carbon Mapping Project.

The climate and the nature crisis.