Over the summer of 2023, volunteers from across the UK recorded 185 hectares of unmapped seagrass meadows in shallow UK coastal waters, in a new annual survey which aims to encourage restoration of the ocean's only flowering plant and the rich ecosystems it supports.

The Great Seagrass Survey, the first of its kind in the UK, is a collaboration between Scottish charity, Seawilding and the British Sub Aqua Club (BSAC). During its inaugural event in May 2023, a team of volunteers scuba dived, snorkeled and strolled the coastline, searching for evidence of seagrass and logging their results.

Seagrass meadows have been described as the most valuable coastal and marine ecosystems on the planet. Despite their benefits, seagrass habitats are under threat from a variety of factors. It is estimated that beds have declined by an estimated 92%. Worldwide, an area of seagrass the size of a football pitch (0.8 hectares) is being destroyed every 30 minutes. Thanks to the Great Seagrass Survey volunteers, a total of 96 beds were mapped around the country, from the Outer Hebrides to the Channel Islands. Both of the two species of seagrass found in UK waters were recorded; Zostera noltei which can be found on the beach at low tide and Zostera marina which is found in shallow waters. The largest area mapped was 78 hectares by the Moray Ocean Community near Inverness.

Volunteers were able to upload their discoveries onto the BSAC website where the information was then analyzed, collated, and shared by Seawilding with national databases making it accessible to scientists and policy makers.

(Image credit: Seawilding)

Locations of the seagrass beds can be viewed on the following interactive map.

“The biggest surprise was how much seagrass was found. Most of the beds they discovered aren’t included in official records and could have been undiscovered for centuries, so this is ground-breaking stuff. By knowing where seagrass is, more can be learnt about the threats it is facing as well as what is required to conserve it.” said project organizer Katherine Knight, Science and Survey Officer at Seawilding.

"Seagrass is notoriously hard to restore once it is lost, so these new beds are incredibly valuable for both biodiversity and carbon capture," said Danny Renton, CEO of Seawilding. "We hope that these patches of endangered and unmapped seagrass - and the ones that the survey will reveal in the future—can be the cornerstone of new restoration projects inspired and driven by coastal communities."

Mary Tetley, CEO of BSAC said: "It’s great that volunteer BSAC scuba divers and snorkelers are helping to map UK seagrass beds. As custodians of the underwater world BSAC members are well placed to assist Seawilding and our environmental partners build up a picture of these precious coastal habitats and help protect them for the future. The forthcoming BSAC Underwater Surveyor course will give members a great skillset for becoming citizen scientists."