Isle of Scilly – Seagrass
Seagrass is a flowering plant that grows in the sea. It is more closely related to plants on land than to seaweed.
Horizontal roots connect plants together to form a mat on the seafloor.
It forms dense underwater meadows in sheltered coastal areas with gentle currents.
There is around 3 kilometres squared of seagrass in the Isles of Scilly Special Area of Conservation.
Our seagrass habitats are some of the best in the British Isles, but more research is necessary to understand the full condition and extent.
What does seagrass do for us?
Seagrass takes up carbon for growth and stores large quantities in its roots. It is globally important for its potential to mitigate climate change.
Each year Isles of Scilly seagrass meadows store the amount of carbon produced by return flights from Newquay to the Isles of Scilly for 5,000 passengers.
Sediment and nutrient removal
Seagrass meadows act as filters trapping sediment, nutrients and pollutants in their root structure and dramatically improving water quality.
Every 2 years seagrass around the Isles of Scilly removes 5 Olympic swimming pools worth of
sediment and excess nutrients from the water.
Seagrass provides a home, place to reproduce and a safe nursery for many species, including some rare and endangered ones.
2 fish species reproduce in Isles of Scilly seagrass.
7 fish species use Isles of Scilly seagrass as a nursery.
Food from wild caught fish
Healthy seagrass supports many commercial species, ensuring a continuing supply of the fish we eat.
33% of wild caught fish species in the Isles of Scilly are associated with seagrass.
Human happiness and wellbeing
Clear, clean seas rich in biodiversity provide greater opportunities for recreational activities and other benefits for people’s happiness and wellbeing.
How can we help seagrass in the Isles of Scilly?
Voluntary no anchor zone
Each anchoring by a boat can potentially dislodge 4 seagrass plants
In popular anchoring areas, this could damage a significant area of the seagrass bed over time
Advanced mooring systems
Traditional swing moorings damage large areas of seagrass as the chain scours the seabed. Scars are created and carbon storage is reduced. Advanced moorings avoid this.
The scar from 1 swing mooring stops the carbon equivalent of 19 return car journeys from Porthcressa to Pelistry being stored each year.
ReMEDIES project information
Reducing and Mitigating Erosion and Disturbance Impacts affecting the Seabed.
The LIFE Recreation ReMEDIES project (LIFE18 NAT/UK/000039) is financially supported by LIFE, a financial instrument of the European Commission.
The contents of this publication are the sole responsibility of Natural England and do not necessarily reflect the opinion of the European Union.