After five years of work, England’s biggest seagrass-restoration project has come to a close, with its results described as “incredibly promising” for the future.
The £2.5 million LIFE Recreation ReMEDIES initiative, led by Natural England and spearheaded by the Ocean Conservation Trust (OCT), tackled the restoration of more than eight hectares of seagrass beds in Plymouth Sound Special Area of Conservation (SAC) and the Solent Maritime SAC.
The project, which also included protection of the hard pink coralline algae called maerl, involved tackling pressures on natural habitats such as recreational anchoring and mooring and educational outreach, along with trials of several seagrass-restoration methods.
A headline achievement was the boosting of seagrass seedling germination success rates from 5% to 33% – a result the team says promises to transform restoration efforts worldwide. Early regrowth is already said to be visible at both project sites.
ReMEDIES, which stands for Reducing & Mitigating Erosion & Disturbance Impacts affEcting the Seabed, was funded by the EU LIFE programme and also involved the Marine Conservation Society, Royal Yachting Association and Plymouth City Council / Tamar Estuaries Consultative Forum.
Trial methods
The OCT says that the project gave it the opportunity to restore the key Zostera marina seagrass species using two trial methods.
The first of these, seed broadcasting, involved both deploying hessian bags containing seed and, over an equal area, using an innovative injection device called Hydro Marine Seeding (HMS) OCToPUS (Ocean Conservation Trust ‘o’ Pressurised Underwater Seeder).
The second method, seedling translocation, meant growing adult plants from seed using “Seagrass Mat Technology” in a laboratory at the National Marine Aquarium, which is run by the OCT. The plants were then deployed at the restoration site.
As a result of these experiments the habitat-restoration team now believes that the best way to achieve sub-tidal seagrass restoration could be through HMS combined with Seagrass Mat Technology. Preliminary results are already said to be showing some regeneration of the seagrass beds, which the team will continue to monitor.
“Seagrass restoration is not without its challenges but, despite this, the ReMEDIES project has pushed boundaries in developing large-scale sub-tidal seagrass restoration,” said Mark Parry, the OCT’s head of ocean habitat restoration.
“It’s been great trialling innovative restoration techniques and seeing the success of our efforts in both Jennycliff Bay and the Solent Maritime. We are excited to continue our learning and development of large-scale restoration efforts in our Blue Meadows project.”
Hand-picked by divers
Because seagrass seeds can be hand-picked by divers only once a year, when the plants flower, the OCT developed a type of seed-storage facility that could allow it to restore meadows year-round. The seeds are maintained in a dormant state in a high-saline, chilled recirculatory system.
Once removed from dormancy, volunteers care for the seeds through to the seedling and adult plant stages as they grow within the Seagrass Mat Technology.
“The ReMEDIES project has been hugely challenging in complexity, scale and ambition, combining recreational pressure-reduction in fragile seagrass habitats with restoration as an additional tool to help it recover,” commented project manager Fiona Tibbitt.
The seagrass-cultivation facility at the aquarium will continue to showcase the project, which was sponsored by Valeport, Zurich and Naturesave Insurance.
Also on Divernet: HMS OCTOPUS ARMS DIVERS TO SOW SEAGRASS FAST, ‘I’VE BEEN LISTENING TO SEAGRASS MEADOWS’, SEAGRASS LIFTS ‘BLUE CARBON’ HOPES IN CORNWALL, GREAT SEAGRASS SURVEY SURPRISES ORGANISERS, BIGGEST SEAGRASS BED YET IDENTIFIED IN CORNWALL
