Posidonia meadows in Port Stephens are the 2nd most impacted by traditional swing moorings in NSW. Traditional, fixed block-and-chain boat moorings scar the seafloor and remove seagrass shoots, causing the formation of bare patches that fragment the meadow and destabilise the sediment. Environmentally Friendly Moorings (EFMs) are an alternative to traditional boat moorings that are slowly replacing traditional block and chain moorings in many coastlines worldwide. The Operation Posidonia team has been working to address the loss of Posidonia meadows in Port Stephens, promoting the recovery of Posidonia by combining the restoration of Posidonia in old mooring scars where swing moorings have been removed. Naturally-detached rhizome fragments were collected from the shore by citizen-scientists, stored within aquaculture tanks and then planted underwater. Results were extremely promising, some areas showing up to 70% survival of transplanted Posidonia, with fragments producing new shoots after only 6 months.
Seagrass
Method: Hybrid
Seagrass species: Posidonia australis
Planting density: 1/20cm
Hybrid structure: Environmentally friendly boat moorings, jute matting
Approach
Seagrass
Geographic context
Bay
Organisation responsible
Operation Posidinia (UNSW, UWA, NSW DPI)
Primary objective
Habitat restoration
Coastal hazard
Erosion
Asset vulnerable
Natural
Date of completion
Ongoing since 2018
Cost ($AUD)
$95,954
Source of project funding
State government
Ferretto, G. et al. Naturally-detached fragments of the endangered seagrass Posidonia australis collected by citizen scientists can be used to successfully restore fragmented meadows. Biological Conservation 262, (2021). https://doi.org/10.1016/j.biocon.2021.109308
Restoring underwater meadows – Operation Posidonia
Project details and images © 2021 Operation Posidonia.