Seagrass loss in southeast Tasmania, particularly in Ralphs Bay, Derwent Estuary, has been significant, with complete disappearance of seagrass beds (Zostera muelleri and Heterozostera nigricaulis) before 1990 due to poor water quality. Despite improvements, natural recovery has not occurred.
In response, this project reviewed literature on Zosteraceae restoration globally. Four methods were adapted for Zostera muelleri, including plug and shoot transplants, direct injection seeding, and seed bags, each tailored to site conditions. Trials were conducted at three restoration locations and a control site with existing seagrass.
Data on costs, time, and impact on donor meadows were collected for scalability assessment. Monitoring over 12 months tracked transplant survival and growth, and seed germination and development. Trials also refined seed-based methods, testing different seed bag designs and storage solutions to prevent fungal contamination.
Initial results show promising transplant survival rates (60-90%) at two restoration sites and the control site, with seed germination observed in seed bags but not in direct injection seeding. These findings aim to inform and catalyse community restoration efforts in Ralphs Bay and beyond