Superhero of the Sea

Superhero of the Sea

With an evolutionary history dating back to the age of dinosaurs, seagrass has stood the test of time. Yet, underwater meadows of this special and once common marine plant are on the brink of being lost from our seas. Now, the Trust is on a mission to sow the seeds of change and recover the Solent’s lost seagrass habitats.

Imagine having the superpower to simultaneously fi ght climate change, provide wildlife with shelter, limit coastal erosion and inspire people to take action for nature.

Now suppose this miraculous ability belongs to a single plant. It sounds like something deserving of protection in the most secure vault at Fort Knox, right?

Yet sadly, despite having the potential to exist around the entire UK coastline, we may have lost up to 92% of this extraordinary plant in the last century. The wonderplant in question is, of course, seagrass.

This special marine plant is known as an ecosystem engineer because it can profoundly change the environment in which it’s found.

In the Solent, there are primarily two species of seagrass: common eelgrass (Zostera marina) and dwarf eelgrass (Zostera noltii).

Unfortunately, neither have been immune to the catastrophic declines experienced elsewhere in the UK. But, if given a chance, they can bounce back.

Hampshire & Isle of Wight Wildlife Trust, in partnership with Boskalis Westminster and the University of Portsmouth, is on a mission to recover the area’s lost seagrass populations through its Solent Seagrass Restoration Project.

Here, we focus on the spectacular benefi ts of seagrass, what we’re doing to help and how you can get involved too.

Seagrasses typically occur along shallow, sheltered marine coastlines and estuaries, from the Tropics to the Arctic Circle. They have roots, grass-like leaves and are the only fl owering marine plant. In the right conditions, seagrasses can grow to form luscious, dense underwater meadows with myriad benefi ts to wildlife and people.

Capturing ‘blue’ carbon

Seagrasses are crucial allies in the fi ght against climate change.

Globally, seagrasses cover just 0.2% of the sea fl oor yet account for a mighty 10% of the ocean’s total carbon capture. One study estimated a tropical species of seagrass (which doesn’t occur in the UK) can absorb carbon up to 35 times faster than rainforests.

Like all plants, our native seagrasses photosynthesise and sequester massive amounts of carbon dioxide from the surrounding seawater. Seagrass stores carbon and off ers shelter to wildlife.

But more importantly, their long leaves also slow the fl ow of water, which allows carbon-rich particles in the water to settle into the seabed where it’s buried and can remain locked away for millennia.

Wildlife-rich sea meadows

Seagrasses support rich biodiversity, including marine creatures like sea horses, stalked jellyfi sh, sea anemones, pipefi sh and sea slugs.

They act as nursery habitats for commercially important fi sh, such as cod, plaice, herring and sea bass, the last of which spend up to seven years maturing in the Solent before joining migratory adult populations. Cuttlefi sh, meanwhile, visit seagrass meadows to breed, attaching their black eggs – known as ‘sea grapes’ - to the plant’s leaves.

Seagrasses also provide a major food source for birds like brent geese, which journey 3,000 miles from Siberia to the Solent every year for milder winters.

Ecosystem services

The extensive root system of seagrass helps stabilise the seabed, while its long leaf blades slow ocean currents, which reduces the size and power of waves and causes them to break further away from the shoreline. This mitigates coastal erosion and flood risk, especially during storms.

This phenomenal plant also improves our seawater quality by trapping sediments in its roots, oxygenating the water and absorbing contaminant nutrients in runoff from the land.

Inspiring people to act

Another overlooked, yet critical, superpower of seagrass is its capacity to inspire people about their local marine environment.

Ellie Parker, who coordinates the Trust’s seagrass volunteer engagement as part of her role as Marine Offi cer, says: “I strongly believe our experiences within nature allow us to form a connection to, and an appreciation of, our environment – along with the desire to protect it. And I think seagrass has a very important and exciting role to play in this.

“The fact our Solent Seagrass Restoration work happens on the shore rather than out at sea allows us to engage a wider audience as it’s easily accessible by foot.

“This allows volunteers of various ages and backgrounds to experience the wonders of our marine environment fi rst-hand.”

Ellie adds: “Without the support of volunteers, the huge amount of work required to help recover seagrass in the Solent simply wouldn’t be possible.

Hand planting seagrass seeds at Seaview on the Isle of Wight.

Hand planting seagrass seeds at Seaview on the Isle of Wight.

KATE GARNHAM

Indeed, volunteers are vital to the Trust’s seagrass restoration project. With their help, we can monitor and survey existing seagrass meadows, collect seagrass seeds and plant them back out into the Solent.

How we’re helping

Sadly, our seagrass meadows are under threat. Disease, physical disturbance from dragging anchors and chain moorings, as well as threats from human activities such as pollution are putting seagrasses under signifi cant pressure.

To support its recovery, the Trust has hand-planted over 40,000 seagrass seeds in the Solent’s shores since December last year. Excitingly, we recently discovered the fi rst signs of seedling growth at our planting site at Seaview and we’ll closely monitor the health of these, plus other existing meadows, through the summer.

Later this year, we’ll sustainably collect more seagrass seeds from harbours around the Solent and replant them elsewhere in the region as we continue our restoration work.

As superheroes go, seagrass is one clean, green, planet-saving machine. It just needs a helping hand to do its thing.

Get involved

To learn more about our seagrass restoration work, fi nd out how to become a volunteer Solent Seagrass Champion or sign up to our regular seagrass newsle er, visit:

hiwwt.org.uk/seagrass-restoration

IN NUMBERS

Seagrass volunteers

• A total of 95 people are currently signed up as Solent Seagrass Champions

• So far this year, Seagrass Champions have commi ed 158 volunteer hours

• We have Seagrass Champions of all ages, from 18 to 68, and around a quarter of our volunteers are under the age of 25

Seagrass offers a home to fascinating wildlife like anemones.