Meadows of seagrass are one of our great but sorely neglected wild plant spectacles. This humble plant spreads out in lush green carpets that can stretch for miles around much of Britain’s coast. There they shelter young fish and shellfish, as well as protecting against erosion of the coast by storms and floods, by trapping sediment in their roots.



And the seagrass meadows also play a big part in fighting climate change. They soak up carbon dioxide and hold tremendous stores of carbon on the sea floor, more than twice the carbon stored by a forest of similar area. And across the world, seagrasses are believed to lock away more than 10% of all the carbon buried each year in the oceans.

Species and habitats found in recommended marine conservation zones – in pictures Read more

Seagrasses around the UK are in serious decline, though, and their immense reservoirs of carbon are being released. Development and dredging are to blame, as well as pollution from sewage and farming washing huge amounts of nutrients into the sea, which kills the seagrasses. Old sewage plants overflow with untreated sewage during heavy rainfalls, which is illegal but common. And excessive nutrients from livestock waste slurry runs off into rivers and ends up in the sea.