Cornwall Wildlife Trust

The Cornwall Wildlife Trust Living Seas team leads a diverse range of successful marine conservation projects and campaigns across Cornwall. In Spring 2024, the team secured a £2,500 Sea-Changers grant to support their research into intertidal Zostera Noltei seagrass restoration in the Helford Estuary.

Zostera Noltei is a seagrass species commonly found in intertidal mudflats and shallow bays around the UK. Seagrasses like Zostera Noltei capture carbon dioxide through photosynthesis, trapping it in their roots and surrounding sediments. This "blue carbon" storage plays a crucial role in mitigating climate change.

Funding was used to analyse nine sediment cores from the Helford Estuary. These long cylindrical sections of mud and sand collected from the estuary floor act as natural time capsules showing how layers of sediment and the materials within them have built up over many years. The analysis, carried out by the University of Exeter, measured how much carbon is stored in the sediment, identifying it as an appropriate location for seagrass restoration efforts due to the high levels found. As one sample contained remains of Zostera marina (eelgrass), it suggests the area previously supported healthy seagrass beds. Measuring carbon storage before and after restoration is important for understanding the impact of such conservation efforts.

Now this site is confirmed as suitable for intertidal seagrass restoration, the Living Seas Team’s long-term vision is to restore Zostera Noltei where it has been lost historically through “active nature restoration – not just the protection of what remains.” Their vision is for local community conservation groups to be “gardeners of the sea”, tending to restoration meadows overseen by Cornwall Wildlife Trust.