In May 2021, Falmouth Harbour removed 11 swinging moorings that were having a localised impact on our Flushing Seagrass bed and implemented a Voluntary No Anchor Zone. Here we provide information on how the Seagrass is recovering.
Above Photos taken by Matt Slater, Cornwall Wildlife Trust
How do moorings impact Seagrass?
Traditional swing moorings are made up of a heavy granite block, a section of heavy chain and a riser chain which is attached to a buoy. Swing moorings have a localised impact on the seabed because a section of heavy chain lies on the seabed and moves around with wind and tide. The movement of this heavy chain across the seabed damages the seagrass and prevents it from growing. We have removed the moorings to remove this impact and allow the seagrass to regenerate. Further information on the impacts of anchoring and mooring are available here.
How are we measuring Seagrass regeneration?
Volunteer divers from Cornwall Seasearch and the University of Exeter are helping to monitor the regeneration of the seagrass within the Voluntary No Anchor Zone (VNAZ).
The site was dived in August 2021 and May 2022. The divers assessed each mooring area from the centre of each scour patch in four different directions NE, SE, SW and NW, to measure the extent of the seabed scouring. Some of these scour patches have reduced in size showing that seagrass has managed to re-grow in scoured areas. For further information please click here.
There are some anomalies in the data which are difficult to attribute to a single cause. We aim to continue the dive surveys and increase understanding around these anomalies.
What's next for our seagrass?
Falmouth Harbour have secured funding for the trial of an Advanced Mooring System (AMS) which has been designed to hold a vessel. It is hoped this will increase understanding of how an AMS performs within the harbour.
Please keep in touch with our social feeds for updates on progress.