Seagrass – Underwater Heroes

In the fight against climate change and the biodiversity crisis, seagrass is one of nature’s unsung heroes – but it’s under threat. In the past 40 years, almost 40% of UK seagrass meadows have been lost.

What is seagrass?

It’s not seaweed and it’s not grass, it’s a flowering plant. In fact, it’s the only flowering plant that lives in the sea, forming lush, green, meadows in shallow waters where there’s lots of light for energy and growth. The UK is home to three species, covering over 8,000 rugby pitches worth of meadows.

Why is seagrass so important?

Seagrass provides homes for thousands of species, supports fisheries and improves water quality. It also absorbs and stores carbon and protects coastlines, increasing our resilience to climate change.

Provides habitats

Seagrass meadows are used as nurseries for 20% of global fishery species, and are home to cuttlefish, sea hares, common spider crabs, snakelocks anemones, short-snouted seahorses, compass jellyfish, and small-spotted catsharks...
Stores carbon

Seagrass meadows can absorb 35 times more carbon dioxide than tropical rainforests and although they make up just 0.1% of the ocean globally, they store 10% of its carbon.
Protects coastlines

Seagrasses have extensive underground root and rhizome (horizontal stem) systems, that form stabilising mats beneath the seabed.
Improves water quality

Seagrass meadows absorb nutrients and their root systems limit the movement of sediment – creating clearer waters and safer habitats.

Map of UK showing seagrass conservation sites along the south coast of England

Conserving seagrass

Seagrass is an endangered habitat. Damage to the seabed by fishing and boat anchors, as well as pollution from sewage and farm run-off, means that seagrass meadows in the UK are declining by 10% each year. Thankfully conservation projects are making a difference.

ReMEDIES (Reducing and Mitigating Erosion and Disturbance Impacts affEcting the Seabed) is a £2.5 million, five-year, marine conservation project, aiming to increase the area of seagrass meadows in five special areas along England’s south coast. Alongside volunteers, the team is collecting seeds, growing seedlings in the lab at the National Marine Aquarium in Plymouth, and planting them out in the sea.

ReMEDIES is funded by the EU LIFE programme and led by Natural England in partnership with Ocean Conservation Trust, Marine Conservation Society, Royal Yachting Association and Plymouth City Council.

Find out more

How you can help seagrass

1. Become a citizen scientist

2. Take care at the coast

3. Be a responsible boater

4. Reduce pollution

The future of seagrass

Due to conservation efforts, certain species of seagrass are starting to see improvements, but much more is needed. Together we must protect and restore these magnificent habitats.