FAQs

Blue carbon wetlands are coastal ecosystems – usually composed of mangroves, tidal marshes, supratidal forests and seagrasses. You’ll find them where land and sea meet.

Blue carbon wetlands draw down large amounts of carbon dioxide from the atmosphere and store it in sediment and vegetation. This process is known as ‘carbon sequestration’. The unique hydrological conditions in these wetlands create an environment conducive to long-term carbon storage.

Blue carbon wetlands provide many ecosystem services. They remove carbon from the atmosphere and store it within the wetland. Coastlines are better protected by reducing wave energy and erosion. Water quality improves by wetlands filtering pollutants. Blue carbon wetlands also support fisheries and recreational activities plus reduce the impact of floods and storms.

A team of leading scientists from Australian universities developed a model known as the Blue Carbon Accounting Methodology (or BlueCAM). BlueCAM, which forms part of the Australian Blue Carbon Method, calculates the net carbon abatement that occurs when a particular land cover (e.g. a crop or pasture) transitions to a blue carbon wetland. This calculation includes the carbon captured and stored in soils and vegetation, as well as avoided land use emissions (for example methane that ceases to be emitted from the site).

Blue carbon restoration under the Australian Blue Carbon Method involves removing or modifying a tidal barrier and reintroducing tidal waters to low lying coastal land. This stimulates the growth of mangroves, saltmarshes, and supratidal forest. As vegetation grows and sediment accumulates on the site over time, carbon is sequestered. In some instances, methane emissions from the are also eliminated. Each tonne of carbon that is sequestered or methane that is no longer emitted is equal to one Australian Carbon Credit Unit (ACCU). If all of the requirements under the Blue Carbon Method and broader legislative framework are followed, it is possible to claim Australian Carbon Credit Units (ACCUs). ACCUs are always issued in arrears i.e. after it has been demonstrated that the equivalent volume of carbon has been sequestered or methane emissions reduced. Additionally, there are international blue carbon methods which can be applied in Australia. International blue carbon methods adopt a range of approaches for calculating carbon sequestration. These can include direct sampling and/or the use of models and datasets from peer-reviewed literature. These methods are also capable of generating carbon credits.

Any carbon credits that are generated from a restored blue carbon wetland can be sold. Potential purchasers include companies, governments and even individuals looking to offset their carbon footprint. Income from the sale of carbon credits can help landowners diversify their revenue streams.

Restore Blue's staff are experts in blue carbon wetlands, with over 25 years of on-ground experience. We offer an end-to-end restoration service. This includes assessing the feasibility of a site for blue carbon, project design, registering the project with the relevant regulator, project implementation and ongoing management or co-management of the site. We are also able to assist with the sale of carbon credits. Our monitoring, verification and reporting (MVR) systems help to quantify and validate the benefits that arise from a blue carbon project. Capturing this data is vital as it demonstrates that environmental gains are real and the project is credible.

While it's true that rising sea levels can lead to the natural migration and restoration of some blue carbon wetlands, this is not likely to occur in the majority of cases. Tidal barriers A primary cause of coastal wetland loss in many parts of Australia is the installation of tidal barriers such as floodgates, bund walls and levee banks which restrict the tide. This was done to allow the land to be cleared, drained and reclaimed for other purposes, often agriculture. As coastal wetland ecosystems require regular tidal inundation to survive, it is necessary to modify or remove these structures to allow the tide to re-enter the site and in turn restimulate the growth of mangroves, saltmarshes and supratidal forest. There is a strong incentive to maintain and even improve these structures to allow for agricultural land use to continue. If they are not maintained to keep up with sea level rise, they will eventually be overtopped by the tide. However, the pace at which this will likely happen varies from place to place, and could be several decades to hundreds of years into the future depending on the structure and other factors. Coastal wetlands need time to grow and adapt Waiting for tidal barrier structures to be overtopped by the tide at some point in the future is likely to jeopardise the successful establishment of blue carbon wetlands. Why? Well, in order to keep pace with sea level rise, these ecosystems need a sufficient runway of time to vertically accrete (that is, to build up sediment and elevation). If they are not given enough time to build elevation, and as sea level continues to rise, a likely outcome is that when the structures are finally overtopped, pools of open water will form. Crucially, these pools will likely be too deep to enable the establishment of blue carbon wetlands. A strategic approach is best It is far more sensible to take a strategic and controlled approach to tidal reintroduction as this provides landholders and local communities with greater choice over what happens, and where. This proactive approach also ensures wetlands are restored in the right places – and on the basis of the most up-to-date scientific evidence – thereby giving them best chance of survival as sea level rise occurs. Land use transition Establishing blue carbon wetlands now not only provides multiple environmental benefits, it allows landholders in vulnerable, low-lying areas to generate an alternative source of income.

Restored blue carbon wetlands provide many ecosystem services which can benefit local communities, such as: Climate change mitigation and adaptation Flood and storm protection Enhanced fisheries and biodiversity Improved water quality Cultural & heritage value Increased tourism, economic opportunities and job creation