Welcome to the Coastal Carbon SA website!
We are a group of multidisciplinary scientists working together to improve our understanding of the ecological and economic value of South Australia’s coastal ecosystems for the uptake and storage of carbon. To find out more about the scientists involved, take a look at the Research Team page!
What is coastal carbon?
Coastal carbon (sometimes called ‘blue carbon’) is the carbon stored in coastal ecosystems. Carbon is accumulated into blue carbon ecosystems in two ways:
1) It is taken up by the plants as CO2 (carbon dioxide) directly from the atmosphere. CO2 (carbon dioxide) is a gas that forms an important component of the Earth’s atmosphere, as well as being a potent greenhouse gas. Although CO2 is a naturally occurring gas, it is also a by-product of burning fossil fuels (like coal, oil and gas), burning biomass, land-use change and industrial processes like the production of cement.
All plants take up CO2 from the atmosphere for use in photosynthesis – a process powered by energy from the sun that creates molecules (e.g. sugar), which the plants need to live. This process of taking in CO2 and making energy forms a key part of the global carbon cycle.
2) Organic materials (predominantly made of carbon) are accumulated in the ecosystems and buried in the sediment. For example, this occurs when rainfall and river run-off from the land passes through the coastal vegetated ecosystems and silt and other organic matter gets trapped in the roots the coastal vegetation. When this happens, the trapped organic matter (carbon) becomes incorporated into the sediment and is eventually buried under the next load of organic material that is trapped there.
The organic carbon that ends up in coastal vegetated ecosystems may be stored for 100s to 1000s of years, both in the actual plants themselves and in the soil below them. This process is called carbon sequestration. Carbon sequestration into vegetated ecosystems is especially important because the amount of CO2 in the atmosphere has increased to dangerous levels (due to human’s burning fossil fuels), leading to climate change. Plants are doing us a favour (an ‘ecosystem service’) by taking up some of the excess CO2 and storing it away, so it cannot contribute to climate change.
Coastal carbon ecosystems are vegetated coastal ecosystems, such as seagrass meadows, mangrove stands and saltmarsh areas. These coastal ecosystems can sequester at least twice as much carbon per km2 than terrestrial forests, so they are very valuable for climate change mitigation.
Coastal carbon ecosystems also provide other ecosystem services. They provide habitats for marine species, including many commercially important fishes; they protect coastlines from waves and storm surges; they improve water quality through filtration and flow regulation, and they support food security and livelihoods in some coastal communities.