Planting the seeds of seagrass restoration with Cornwall Wildlife Trust

In July 2022 we launched our Seeding Change Together partnership project with Cornwall Wildlife Trust. We’ll be donating £150,000 over the next three years to support the Trust’s marine conservation team as they carry out planting trials on the site at the Fal-Ruan nature reserve. 

The aim is to restore and expand the coverage of seagrass beds across Cornwall. As seagrass grows, it helps us with our battle against climate change by drawing carbon dioxide from the seawater, storing carbon in its roots and leaves and releasing oxygen for us to breathe.  

We caught up with Sophie Pipe, Seagrass Project Officer at Cornwall Wildlife Trust, as she planted the all-important harvested seagrass seeds on site at the Fal-Ruan nature reserve. 

“After harvesting seeds from the existing healthy seagrass beds, it’s now time to plant them in areas where we need seagrass to grow. We’ve selected this particular area of the reserve because there is a small amount of seagrass present, but not enough for the bed to be stable. So that’s why we’re trying to give it a helping hand.” 

“When we harvest our seeds, they’re stored in an air pocket within the plant’s leaf. Over time this tissue rots down, which is what releases the seeds.” 

“To plant the now-released seeds, we put them into our mud mix, which goes into our hessian bags. The mud mix is made up of the top layer of our sediment from our mudflats. We use this because it’s got lots of oxygen in it, so it’s nice and aerated, which helps our seeds.”

“We plant the seed-filled hessian bags a metre apart. The reason we do this is because hopefully when the seeds establish, the roots and the rhizomes will spread across a metre and should start to connect with one another to form a meadow.” 

Before planting the bags, we first dig a little bit down from the surface of the mud flat. We don’t want to be digging too deep because the further down we go, the less oxygen there is. We then place our bags upside down to anchor them into the soil and put about a centimetre of sediment from the mudflats on top of them to bury them. We use old bodyboards to lean on while planting, to mitigate any disturbance on our beds here.

“Now it’s a bit of a waiting game. We hope to see our seagrass shoots appear in the late spring to early summer.” 

Watch this space for more exciting project updates in the months ahead. To find out more about seagrass and our Seeding Change Together restoration project, visit cornwallwildlifetrust.org.uk/seagrass