6200ha of seagrass has been lost from the Adelaide coast since 1949. This has caused 100,000m3 of sand to be deposited on Adelaide beaches per year, and increased coastal erosion due to increased longshore movement of sand. Additionally, the loss of this habitat has affected many important fish species and overall biodiversity of flora and fauna in the region. Much of the loss has occurred in shallow waters up to 7m depth, progressing seaward, with the primary cause considered to be anthropogenic nutrient inputs. In response to this loss, improvements to waste and storm-water systems were implemented, resulting in some natural recolonisation in deeper waters. However, no natural recovery has occurred in shallower waters. To address this, the Australian Federal Government Department of Agriculture, Water and the Environment awarded $1,972,500 in funding to restore 20 hectares of seagrass off Port Gawler, north of Adelaide. The project will involve dropping around 100,000 hessian sandbags and allowing seagrass seedlings to naturally attach to the stabilised sediment. The project will be led by the University of Adelaide, South Australian Research and Development Institute (SARDI) and the research division of the SA government's Department of Primary Industries and Regions (PIRSA).

Seagrass

Method: Hybrid

Hybrid structure: Hessian bags filled with sand