Damage to seagrass by the traditional anchoring of boats on the seabed, has reduced by more than 90 per cent within five years since eco moorings have been introduced in Studland Bay in Dorset, according to new research conducted at Southampton University.
The scientific study started in 2021 when the first eco moorings were installed, and then the 39 damaged areas of seagrass on the seabed were annually tracked over the next five years.
The chains of traditional boat anchors uproot the seagrass
Bare patches in the seagrass shrank
Traditional anchors with heavy metal chains can scour the seabed and uproot seagrass with the movement of the tide, however eco moorings operate on a spring system which are designed to avoid damaging the seagrass.
Seagrass is not only a habitat for Studland’s rare seahorses but is also important for storing carbon, supporting biodiversity, and helping protect coastlines from erosion.
Using sonar surveys, historical satellite imagery and five years of monitoring data, the study found every anchor chain scar examined showed signs of recovery, once ongoing disturbance had ceased.
In the area where 10 trial eco moorings were installed in 2021, the size of bare patches in the seagrass decreased by an average of 93.6 per cent between 2021 and 2025, shrinking by around 57 square metres each year.
In a second study area, where traditional chain moorings remained until 2023, the scars reduced by 65.4 per cent, equating to around 15.9 square metres per year.
Crucially, researchers found no significant change between 2021 and 2023, suggesting recovery only began once alternatives to traditional anchoring became available.
The first of the new eco moorings were installed in Studland Bay in 2021
It’s a voluntary no anchor zone and while some boat owners don’t comply, many are happy to use and pay for the eco moorings provided
“Robust scientific evidence”
The research was conducted by Kira Dunn as part of her MSc in marine biology with oceanography at the University of Southampton. She said:
“This was a really rewarding and positive project to work on. The results clearly show that seagrass is recovering in areas where physical disturbance has been removed.
“It’s incredibly encouraging to see how quickly this important habitat can regenerate when given the opportunity.”
Dr Ken Collins from the University of Southampton and supervisor of the study, added:
“This research provides robust scientific evidence that eco moorings are an effective tool for seagrass conservation and restoration.
“The findings support the continued use and expansion of eco mooring schemes, not only in Studland but in other sensitive marine environments where seagrass habitats are under pressure.
“Studland Bay is becoming a powerful example of how practical conservation measures can reverse habitat damage and deliver measurable environmental improvements.”
Kira Dunn (left) and Dr Ken Collins (right) on Studland Beach
Evidence that the seagrass will grow back if left undisturbed is being used to show that the eco mooring scheme is worthwhile and working
“New seagrass growing back”
Studland Bay was designated a Marine Conservation Zone in 2019, and became a Voluntary No Anchor Zone in 2021, to help reduce disturbance to the sensitive habitat.
The Studland Bay Marine Partnership was formed in 2021 to bring together the organisations and individuals committed to protecting and enhancing the seagrass meadows, while still allowing people to enjoy the bay.
Chair of the Studland Bay Marine Partnership steering group, and lead ecologist for the National Trust, David Brown said:
“The findings are incredibly exciting, and a huge encouragement to all the organisations and individuals who have given so much time and support to the partnership.
“We had previously mapped all the anchor scars in the seagrass, and this research shows that every one of them is healing, with new seagrass growing back.
“The impact has been beyond our expectations, and thanks to robust monitoring and research, we have the science to prove how the eco-moorings benefit seagrass and all the species that rely on it.”
Further information
- More about Studland Bay, seagrass, and the eco moorings on the Studland Bay Marine Partnership website
