Seagrass and the Sound: 10 years of monitoring, protection & restoration
Core programmes
A Power Plant
• The Ocean’s only marine flowering plant
• Grows in shallow, sheltered, sunny waters
• Worlds 3rd most valuable habitat [1]
• Carbon Capture
• Biodiversity hotspot
• Nursey ground
• Nitrogen fixing
• Community wellbeing
• Coastal protection
[1] Esteban, Unsworth, 2018
Human Behaviour: The main cause of decline
One the planet’s most endangered habitats
Lost about 40% since the 1980's [2]
Numbers still in decline across the globe, faster than rainforests
[2] Green, 2021
Human impact
Blue Meadows
• Aim: Protect 10% of UK seagrass by 2030
• UK’s largest restoration programme at scale
‘Protect what we have and restore what we have lost’
• Subtidal species: Zostera marina
Our History with Seagrass…
2013
Citizen science programme
2019 - 2023
5 year EU LIFE funded habitat restoration project
2022
Holistic approach to seagrass conservation
Protection
Highlight the presence of seagrass habitats
Voluntary No Anchor Zones (VNAZ)
74 buoys
Protecting 215ha
Regeneration Advanced Mooring Systems
Reduce abrasions from traditional mooring chains
212% increase in seagrass cover [3]
[3] Jean-Luc Solandt, 2024
Restoration
National Seagrass Nursey
8.3 + hectares
Across 3 sites
Restoration Seedbags
Se
edMat
Tech n o logy Hy d r o marineseeding
HMS OCToPUS
In 1 hour with 6 divers can replant 1 hectare!
Engagement
'Connect communities along the southwest to their local seagrass and empower them to take action'
Promoting pro-ocean behaviours
Increasing knowledge
Shaping community voices for seagrass
Monitoring – Core Samples
• 3 sites at each location
• Core to 3m where possible
• Split into 1m sections
• 1 cm slices for analysis (top 1m)
Drakes
Island
• Dive surveys as part of the Citizen Seagrass Imitative (CSI) (2015-2017).
• Divers monitored spatial extent and density along transect lines across the seagrass bed
• Surveys monitoring present fish species using Baited Remote Underwater Videos (BRUVs) among other methods
Cawsand
• 15 Advanced Mooring Systems (AMS) installed at Cawsand in 2021.
• Historically been impacted by ‘scouring’ from traditional chain mooring systems
• Installed to help Regenerate seagrass beds
• Privately Owned
Jennycliff
• Main restoration site in Plymouth Sound
• Yellow marker buoys installed in 2020
• Providing protection
• indicating presence of seagrass – raising awareness
• Volunteer No Anchor Zone (VNAZ)
Jennycliff
• Main restoration site in Plymouth Sound
• 6 years of restoration work
•Seed Bags
•Seed Mat Technology
•Hydro Marine Seeding (HMS)
Jennycliff
• Ongoing monitoring of restoration work effectiveness
• Dive surveys along transect lines - Hydro Marine Seeding & 2022 Seed Mat Technology
• Seagrass growth detected showing restoration success
Jennycliff
• Monitoring seagrass bed extent and density in Plymouth Sound
•Diver surveys
•Remotely Operated Vehicle (ROV)
•Sonardyne
•Hydrosurv
Jennycliff
• Water sample monitoring from seagrass bed and surface water
• Analysis in partnership with MBA
• Looking to develop this area of monitoring
•Consider CSO locations –potential research projects in partnership with OCT
‘Seagrass condition monitoring in Plymouth Sound and Estuaries SAC 2018’ (Natural England)
‘The subtidal and intertidal seagrass beds in the Plymouth Sound and Estuaries SAC are in unfavourable unknown condition.’
Major pressures – Recreational & Water Quality
Combined Sewer Overflow (CSOs) discharge locations
Stay tuned….
More to come from the Ocean Conservation Trust!
