Seagrass regeneration projects in the UK are helping to combat the climate crisis. Here's how

This article was first published on 31 August 2020 and updated on 21 July 2023.

Its waving fronds carpet the seafloor and shelter thousands of sea creatures. But seagrass is more than a haven for marine wildlife – researchers say it could play a major role in tackling the climate crisis.

Seagrass covers just 0.2% of the seabed, yet it accounts for 10% of the ocean’s capacity to store carbon, according to the United Nations Environment Programme. It can capture carbon from the atmosphere 35 times faster than rainforests.

But around the globe, seagrass meadows have declined, and projects like Seagrass Ocean Rescue are working to reverse the trend. The scheme, in conjunction with Project Seagrass, Swansea University and WWF, is seeding coastal waters around the UK to create new seagrass beds.

The UK has lost 90% of the seagrass in its coastal waters and estuaries, according to the project. Since 2019, it's been working "to restore some of what we have lost", including an ongoing reseeding programme in Wales.

There, seagrass seeds are planted on the seafloor in hessian bags, held together on lines of rope. As the hessian degrades, the seeds, collected by divers from underwater meadows in waters off the southern coasts of England and Wales, germinate and establish on the ocean bed.

The goal is to plant 1 million seeds, as well as inspire projects in other areas around the UK.

Scotland is already following suit, with a team currently working on the regeneration of seagrass in the Firth of Forth. Harvesting seeds from the pristine seagrass meadows off Orkney, divers are then planting them in the decimated meadows at the Firth of Forth, hoping to "kick-start a regenerative process", Marie Seraphim of the Scottish Seabird Centre told the BBC.

Seagrass meadows are among the world’s most threatened ecosystems, and they’re rapidly disappearing in many places.

Globally, over a third have been lost in the past 40 years, according to Project Seagrass. Destructive fishing, pollution and the climate crisis are contributing to this decline, it says.

The urgent need to find new ways to capture and store carbon makes the restoration of seagrass vital. Indeed, the UN has called it a “secret weapon in the fight against global heating”.

As well as storing up to 400kg of carbon per hectare every year, seagrass also helps support sustainable fisheries by providing a home for young fish. A study by Project Seagrass found that seagrass fisheries "provide a reliable safety net for poor fishermen".

In the UK alone, 50 different species of fish live in or visit seagrass, which is 30 times more sea creatures than nearby habitats. Seagrass also plays a role in stopping coastal erosion.

The World Economic Forum’s Ocean Action Agenda calls for urgent action to reverse the decline in ocean health, pointing out that seafood is the primary source of protein for 3 billion people.