Eco moorings help Dorset seagrass meadows recover, Southampton study finds

The study, conducted by Kira Dunn as part of her master's degree, analysed data collected since the Studland Bay Marine Partnership installed so-called eco moorings in 2021. In the area where ten trial eco moorings were placed five years ago, bare patches in the seagrass shrank by an average of 94%. In a second study area, where traditional chain moorings remained in place until 2023, the scars were reduced by 65%.

Dunn said the results clearly showed seagrass was recovering in areas where physical disturbance had been removed. She described it as incredibly encouraging to see how quickly the habitat could regenerate when given the opportunity.

David Brown, chair of the Studland Bay Marine Partnership steering group and lead ecologist for the National Trust, said the impact had been beyond the partnership's expectations and that robust monitoring and research had provided the science to show how eco moorings benefit seagrass and the species that depend on it.

The partnership brings together conservationists and boating enthusiasts, among other organisations, and hopes the findings can help protect and restore seagrass in other busy marine environments around the UK.

Seagrass meadows are considered among the world's most valuable ecosystems because they support creatures such as seahorses, store carbon and help protect coastlines from erosion. They are declining globally under pressures including pollution, coastal development and the climate emergency. The meadows at Studland Bay are particularly exposed because the spot is popular with leisure boaters. The bay was designated a marine conservation zone in 2019 and holds one of the UK's largest seagrass meadows, supporting species including the protected spiny seahorse and the occasionally recorded short-snouted seahorse.

Eco moorings consist of a two-metre helical screw drilled securely into the seabed. A two-metre elasticated riser is attached to it and connects to a surface buoy. As the tide rises and falls, the riser stretches and retracts, preventing scouring of the seabed and seagrass.

Since the eco moorings were introduced, volunteer divers who monitor seahorses have reported increases in their numbers. Conger eels, spider crabs and corkwing wrasse have also been recorded in the seagrass.

Ken Collins, emeritus research fellow and diving officer at the University of Southampton, who supervised the study, said the research provided robust scientific evidence that eco moorings are an effective tool for seagrass conservation and restoration. He said the findings supported 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.