In April 2021, ReMEDIES partner Ocean Conservation Trust (OCT) carried out seagrass restoration work across an area of almost one hectare in Jennycliff Bay, Plymouth Sound.

This is part of England’s largest seagrass planting effort, led by ReMEDIES, which aims to restore a total of eight hectares of seagrass meadows – four hectares in Plymouth Sound National Marine Park and four hectares in the Solent Maritime Special Area of Conservation.

Restoration. Photo credit Ocean Conservation Trust
Restoration. Photo credit Ocean Conservation Trust

Around 800,000 seagrass seeds were gathered from healthy seagrass beds off the Cornish coast during a series of seed collection dives in summer 2020. These were cared for over winter at the purpose-built cultivation facility at the National Marine Aquarium (NMA) in Plymouth.

The seeds have been used to fill 16,000 seagrass seed bags - ethically sourced, sustainable hessian bags which break down naturally on the seabed - bagged at the NMA by Aquarium and OCT staff and volunteers. Some seeds were grown to seedling in the cultivation lab and used to fill a further 2,200 bags.

Seed and seedling bags were loaded onto the Cattewater Harbour Commissioners’ barge and taken out into Jennycliff Bay, to the eastern side of Plymouth Sound, where they were sent down four-metre-long tubes to make their way onto the seabed to germinate. Bags were dropped approximately one per second, which should mean a spacing of around one bag every 50 centimetres on the seabed, for an appropriate density of plants.

Seed bag on seabed. Photo credit Ocean Conservation Trust
Seed bag on seabed. Photo credit Ocean Conservation Trust

By restoring seagrass in this way, we’re helping to create healthy seagrass meadows that provide habitat for a number of protected species, are important nursery grounds for fish including commercially important species, help stabilise the seabed and reduce coastal erosion, clean surrounding seawater and store and capture significant amounts of carbon.

A voluntary no-anchor zone around the newly planted area is intended to help protect it from physical disturbance from recreational boating. The Queen’s Harbour Master, Plymouth has issued location details for this zone.

This is just the start of our practical restoration work. OCT is planning to plant a further half hectare in Plymouth Sound in November/December 2021, and planting work in the Solent is scheduled to take place in spring 2022.

Seabed habitats: Restoration and Protection

Watch episode one of our Secrets of the Seabed webinar series led by Ocean Conservation Trust. This first episode focuses on the work ReMEDIES is doing to restore and protect seagrass in five Special Areas of Conservation in southern England.