Seagrass, Solent - 35442 - Theo Vickers

Our new mooring system paves way for significant seagrass rewilding

3 minute read

We’ve teamed up with the Ocean Conservation Trust on a project to restore seagrass, whilst continuing to allow safe boat mooring in Cawsand Bay.

Our new joint report shows there has been a 212% increase in seagrass cover within the mooring area of Cawsand Bay, Plymouth Sound, following the installation of a new 'Advanced Mooring System' four years ago, which protects seagrass whilst allowing boats to safely moor in the area.


Credit: Charlotte Bolton/Seasearch 2020

Dr Jean Luc-Solandt, Marine Protected Areas Principal Specialist, said, “It’s incredibly rewarding to see the seagrass meadows reappear after the installation of the Advanced Mooring Systems, restoring a vital habitat for local biodiversity, carbon storage and coastal protection.

“You can’t get restoration without protection, and by working with the local boating community to protect the seabed, we've collectively given space for this rewilding to take place.”

Against the backdrop of the climate and nature emergencies, the success of this simple system shows how pioneering projects can have a mitigating effect on the impacts of climate change, and reverse local biodiversity decline.

Dr Jean Luc-Solandt, Marine Protected Areas Principal Specialist

The initial project installed five Advanced Mooring Systems in Cawsand Bay, Plymouth Sound, in 2019, with a further 12 added in 2021 after the COVID pandemic.

Traditional moorings consist of an anchor block and a chain attached to a buoy. This chain can create a ‘halo’ around the block where it drags on the seafloor, damaging existing seagrass, and preventing recovery.

The Advanced Mooring System, on the other hand, uses buoys, floats or bungee-type devices to keep the chain off the seabed.

advanced mooring buoy.png

In England, seagrass beds have declined by up to 90% in the past century, as a result of disease, pollution, marine development and infrastructure, and boating activity.

These vulnerable ecosystems have faced additional pressure since the 1990s, with an increase in pleasure boating resulting in more recreational fishing, mooring and anchoring taking place in seagrass habitats.

Cawsand Bay is one of the busiest areas of the Plymouth Sound Special Area of Conservation (SAC), particularly with tourism and small boat use.

We've also been recording species in Plymouth seagrass beds, finding that seagrass areas have up to 70% more animals, and a greater number of different species (7% more), than surrounding sandy areas.

This has been part of the concurrent project, Plymfish, which is in collaboration with the University of Plymouth and is also supported by Princess Yachts.

Seagrass beds act as nursery areas for many juvenile fish. Eggs are laid in and around the fronds by small sharks and cuttlefish, and iconic species such as bass and seahorses use them to shelter, breed and feed.

They're also a vital coastal ecosystem for buffering the destructive power of the sea and its powerful waves, with seagrasses’ root systems locking the sandy seabed together, storing carbon and reducing coastal erosion.

Mark Parry, Head of Ocean Habitat Restoration, at the Ocean Conservation Trust, said: “We are delighted to see the positive effect the installation of the Advanced Mooring Systems has had to increase the presence of seagrass in Plymouth Sound, it’s a big win for this sensitive habitat.

“Protecting and restoring seagrass requires a holistic approach and by finding workable solutions like this, it allows communities to continue enjoying the ocean, whilst having a lesser impact on the environment, allowing both people and nature to peacefully coexist.”

Seagrass bed Georgie Bull

Credit: Georgie Bull

This applied conservation effort with the boating community has significant potential to recover seagrass meadows around the UK coast. We’ll be expanding this work to other sites and invite interested boaters to get in touch for more details.

We would like to thank our partners, the Ocean Conservation Trust, and funders, Princess Yachts. This work was part-funded by the Recreational ReMEDIES project.

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