Victoria’s bays and inlets incorporate more than 60,000 ha of blue carbon habitat including seagrass, saltmarsh, and the world’s most southerly mangrove habitat. Approximately three quarters of Victoria’s blue carbon habitat area is currently in a disturbed or collapsed state – suggesting great potential for restoration work, supported by the blue carbon restoration method for earning Australian carbon credit units.

In addition to carbon abatement, blue carbon habitats can provide benefits in coastal protection from storms, sea level rise and shoreline erosion. Blue carbon habitat restoration planning in Victoria is being considered in conjunction with sea level rise and coastal retreat.

The state government funded 2024 report, Mapping the benefits and costs of management actions for coastal wetlands in Victoria, by researchers from Blue Carbon Lab at Deakin University. The study applied the UN System of Environmental Economic Accounting Ecosystem Accounting (SEEA EA) to develop an ecosystem account for blue carbon habitat across the state.

The SEEA EA analysis found that the benefit provided by existing mangroves, saltmarshes, and seagrasses in Victoria is approximately $120.9 billion per year, almost entirely due to coastal hazard mitigation. To restore blue carbon ecosystems while responding to sea level rise, levee removal to restore tidal exchange, plus managed retreat, could create approximately 124,000 ha blue carbon habitat, the report found. This approach to coastal management in Victoria was the costliest option considered, at $7.6 billion, but created the highest net benefit of $134.8 trillion after 50 years.

An additional report from 2022, Mapping Victoria’s Blue Carbon, has mapped blue carbon areas with high potential across Victoria. The report identified areas of existing habitat in poor condition that may benefit from protections such as fencing to prevent grazing. It also identified priority areas where grazing control, tidal restoration, habitat retreat, or hydrological intervention to expand saltmarsh and mangroves habitat could provide the highest benefits.

Blue carbon habitat restoration pilot projects underway in Victoria include the Port Phillip Bay golden kelp restoration project; a project to protect saltmarsh on the Bellarine Peninsula; and the Western Port Biosphere Foundation project to restore mangrove, seagrass and saltmarsh habitats. The 2,142 km² Western Port Biosphere Reserve includes a quarter of the state’s coastal wetlands. In 2023, the Western Port project was granted $1.2 million of state funding for research, site specific analysis and planning to protect and restore the area’s wetlands.

This case study was prepared by NCCARF.

Please cite as: NCCARF, 2024: Blue carbon habitat restoration in the context of sea level rise in Victoria. Case study for CoastAdapt, National Climate Change Adaptation Research Facility, Griffith University, Gold Coast.