Seagrass restoration trials begin in Cornish river estuary

The first round of a seagrass planting trial on a project in a Cornish river estuary has been completed.

It's Cornwall Wildlife Trust's (CWT) first attempt to restore seagrass meadows in a bid to combat climate change.

The seeds were planted in the River Fal estuary last summer, thanks to funding from Seasalt Cornwall.

If successful, the team hopes to plant more seagrass meadows across the Duchy.

Around 4,000 seeds were collected from stable and healthy meadows in the Fal Estuary at the end of last summer.

Yet researchers were surprised that the seed pods collected yielded only a quarter of the seeds expected.

Marine experts from the charity are concerned that the summer’s prolonged periods of high temperatures may have affected the seeds’ development.

Sophie Pipe, seagrass project officer at Cornwall Wildlife Trust, said: “We experienced record-breaking heatwaves and droughts last summer, in addition to an incredibly mild start to autumn and sudden cold snaps this winter.

"These extreme conditions may have affected the seagrass meadows on site, but it’s an unknown as to what those short-term and long-term impacts will be. That’s why our research is so important.

“We’re hoping to know more when the seedlings sprout in late spring or early summer this year. They could stay dormant for longer than we expect if there’s a temperature drop, or they could sprout early.

“Water quality is also something that may affect the health of the seagrass beds. We’re keen to study that in more detail on the site.”

Newly purchased testing equipment is now helping scientists to understand how water quality is affecting the seagrass populations.

Seagrass is a flowering marine plant that captures carbon from the environment up to 35 times faster than tropical rainforests, making it an important resource in the fight against climate change.

It also provides a habitat for marine life such as juvenile fish and seahorses, cleans surrounding seawater and helps to stabilise the seabed to protect the coast from erosion.

In the UK, approximately 92 percent of seagrass was lost in the last century. The huge decline has been caused by pollution, disease and coastal development.

Paul Hayes, CEO at Seasalt Cornwall, said: “Seeding Change Together is a vital project for the UK’s seagrass restoration efforts and we’re thrilled to be helping play a part in generating this essential research.

"Climate change isn’t a future problem – it’s here and now - and it’s alarming that extreme weather may be impacting the planting trials."

Seasalt Cornwall has committed to donating £150,000 as part of a three-year partnership.

If successful, Cornwall Wildlife Trust hopes the project could lead to large-scale restoration and planting of seagrass in Cornwall’s estuaries.