Seagrass restoration in south australia

securing the future of our coastline - south australia’s biggest seagrass restoration project

Department of environment and Water

The South Australian Government is undertaking the largest seagrass restoration project in Australia through a $1 million New life for our coastal environment project to re-establish around 10 hectares of seagrass off the Adelaide metropolitan coast. 

Seagrass meadows are very important to the nearshore coastal environment. They help stabilise the seabed by holding sand with their roots and reduce the waves and currents near the seabed with their leaves.  They also provide both food and habitat for marine life.

Over the last half century, around one third of seagrass along the Adelaide metropolitan coast has been lost.

While natural events such as storms can cause large-scale seagrass loss, the main cause of the initial seagrass loss was poor water quality resulting from drain discharge, stormwater run-off and effluent disposal.

Once destroyed, seagrass ecosystems do not easily recover as waves and currents erode the exposed seabed and inhibit regrowth.

As seagrass is not easily able to re-establish in bare sand, the seagrass restoration project uses a technique developed in South Australia of placing hessian bags on the sea floor to hold seagrass seedlings in place. By the time the hessian decomposes, many seedlings are sufficiently established.

Trials are being undertaken in 2019 between Largs Bay and Hove, to identify suitable sites for large scale restoration work in 2020. It will take several years for the seagrass to fully establish. The restoration will be monitored to measure and report on progress over time.

The project is being delivered by the South Australian Research Development Institute in partnership with our department and will inform future seagrass restoration work.