Plymouth – 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 0.7 kilometers squared of seagrass in the Plymouth Sound and estuaries Special Area of Conservation.
Our seagrass habitats are in decline, due to poor water quality and disturbance.
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 Plymouth Sound and Estuaries seagrass meadows store the amount of carbon produced by return ferries from Plymouth to Roscoff for 4,250 car 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 Plymouth seagrass removes one Olympic swimming pool’s 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 Plymouth seagrass.
4 fish species use Plymouth seagrass as a nursery.
Food from wild caught fish
Healthy seagrass supports many commercial species, ensuring a continuing supply of the fish we eat.
30% of wild caught fish species in Plymouth 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 Plymouth?
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 1 return car journey from Plymouth to Dartmouth being stored each year.
ReMEDIES is planting 0.04km2 of seagrass in the Plymouth Sound & Estuaries Special Area of Conservation.
10000m2 of healthy seagrass stores the same amount of carbon a year as return trips on the Plymouth to Roscoff Ferry for 61 car passengers.
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.