Blue Carbon Restoration Projects Support the Role of South Australia’s Coastal Wetlands for Climate Change Mitigation

Image: Dry Creek saltfields pilot blue carbon project drone imagery road and tidal gate 2022 credit Emily Leyden

South Australian coastal wetlands provide more than a scenic view. These vital ecosystems capture and store ‘blue carbon’, playing a key role in fighting climate change while supporting biodiversity and livelihoods.

An interdisciplinary team of researchers at the University of Adelaide, including members of the Environment Institute, have come together to help create the first targeted analysis of how blue carbon restoration projects interact with the law in South Australia.  The project sheds light on how South Australia’s legal framework governs the restoration of these ecosystems.

What is Blue Carbon?
Blue carbon is organic carbon that is stored within marine and coastal vegetated ecosystems, like mangroves, tidal marshes, and seagrasses, capturing carbon through photosynthesis and trapping organic matter in the sediments.

These ecosystems offer multiple benefits:

• Biodiversity Boost: Provide critical habitats for foraging, breeding and nursery habitat
• Protection for the Coast: Stabilise shoreline while enhancing water quality by filtering nutrients and pollutants
• Natural Resources: Provide food and other essential natural resources for humans

Many of these ecosystems have been damaged or degraded by human activities and rapid anthropogenic (‘human-caused’) climate change. Once destroyed or degraded, these ecosystems lose their ability to trap and store more carbon and release stored carbon as greenhouse gas emissions, contributing to climate change. So, restoring these systems offers a nature-based solution to climate change, while also providing new habitat for marine and coastal species and protecting the coastline.

How Can We Restore Coastal Wetlands?
One effective method is through ‘tidal restoration projects’. These projects remove barriers such as bunds or seawalls that block tidal flows, or construct culverts and drains to allow tidal inundation to areas behind the barriers. These efforts reintroduce tides to areas that have been drained, and allow coastal wetlands to recolonise in these areas, fostering healthy, functioning coastal environments that capture and store carbon. Restoring these ecosystems not only helps mitigate climate change but also strengthens the natural resilience of South Australia’s coasts.

The Australian Government supports such efforts through the blue carbon method for carbon crediting. This legal instrument enables projects to earn carbon credits, which can then be sold to generate income under the Australian Carbon Credit Units (ACCU) Scheme. Coastal wetland ecosystem restoration projects may also become eligible for funding through the emerging national Nature Repair Market, though specific guidelines for participating in that market are still in development.