Over 2500ha of seagrass meadows have been lost or degraded in Western Cove, Kangaroo Island, due to nutrient and sediment run off. The Australian Government funded a "Catchment to Coast" project to address water quality through restoration of riparian zones. At the same time, seagrass restoration trials were undertaken to support natural recovery. Trials consisted of transplanting sprigs (rhizome with shoots) and direct seeding onto hessian bags placed on the substrate. This work was done largely with the aid of community volunteers, who assisted in planting the sprigs (which were harvested by trained staff members earlier in the day). In 2013, 205 sprigs were planted over an area of 160m2. Survivorship, monitored with assistance from community volunteers, was high after twelve months at 86%. As a result of this success, a second planting day was held in 2014, planting 210 sprigs over two areas, also resulting in high survivorship (85% after 2 months). Finally, seed-based restoration was attempted in which volunteers harvested seeds which were kept in seawater for 14 days and then deposited on hessian bags at restoration sites. This trial was considerable less successful, with only 12% survival after 12 months. Overall, community enthusiasm for the project was high, including support for extending the length and frequency of planting days.

Seagrass

Method: Planting: rhizome fragments, Hybrid

Seagrass species: Posidonia australis

Planting density: 1/m2

Hybrid structure: Hessian bags filled with sand