The Solution
Environmentally friendly moorings coupled with Posidonia Restoration
The only way to prevent damage to the marine environment by boat moorings is to change their design, so that there are no components dragging along the seafloor.
In recent years, a variety of mooring designs have emerged that prevent chains dragging along the seafloor. These new types of moorings are collectively known as Environmentally Friendly Moorings (EFMs), and they are slowly replacing traditional block and chain moorings in many coastlines worldwide, but are not yet used extensively in New South Wales.
Diagram: EFM vs Traditional swing mooring
Once mooring chains are removed, however, the natural revegetation of bare patches by Posidonia can be very slow, especially when mooring scars have expanded and altered local hydrodynamics. In some places it could take over 20 years for a mooring scar to be revegetated by Posidonia naturally.
Our aim is to give nature a helping hand and promote the recovery of Posidonia by combining the restoration of Posidonia in old mooring scars where swing moorings have been removed.
Posidonia restoration is underway!
The scientists behind Operation Posidonia have already done some restoration trials in old mooring scars in Port Stephens that are showing very promising results.
They have deployed jute mats to help stabilise sediments in mooring scars, which also helps to anchor Posidonia fragments. So far, they have recorded ~50% survival of seagrass shoots, with some areas showing up to ~70% survival. These results are very encouraging for transplant methods. Many transplanted fragments began producing new shoots after only ~6 months, meaning they are beginning to expand and revegetate the surrounding area.
Read about the restoration and research here
Operation Posidonia in Lake Macquarie
Operation Posidonia was launched in Lake Macquarie in early 2021. The expansion of the project is very exciting as scientists are now ready to use the methods developed in Port Stephens in an estuary where Posidonia is formally listed as endangered.
Mooring scars in Posidonia meadows are extensive in Lake Macquarie and the Operation Posidonia team aim to reverse some of this damage with the help of the local community.
UNSW Sydney and the Sydney Institute of Marine Science are leading this project in collaboration with OzFish Unlimited, Lake Macquarie City Council, Transport for NSW, Delta Electricity and NSW Department of Primary Industries. The project is supported by NSW DPI Recreational Fishing Trusts, through the Habitat Action Grants program.
Mooring scars in Posidonia meadows in Lake Macquarie
Where to next?
In late 2021, Operation Posidonia will be launched in Botany Bay (Kamay). This highly developed estuary serves as Sydney’s gateway to the rest of the world, housing major shipping and airport infrastructure. It is also home to amazing marine biodiversity, including Posidonia meadows. Operation Posidonia will be working closely with the Gamay Rangers and the Port Authority of NSW, with support from the Wild Elements Foundation.
Operation Posidonia have also secured funding to co-restore Posidonia and White’s Seahorse (Hippocamous whitei) across NSW, assisted by the NSW Government through its Environmental Trust in collaboration with researchers from NSW DPI, UTS and SeaLife Sydney Aquarium.
