Coastal habitats like salt marshes, mangroves, and seagrass beds provide us with countless benefits, from nursery grounds for fish to protection from storms. They also play an important role in addressing climate change by removing greenhouse gases like carbon dioxide from the atmosphere and storing them. The NOAA Fisheries’ Office of Habitat Conservation works to protect and restore these important coastal habitats and the climate benefits they provide.
What is Coastal Blue Carbon?
Coastal blue carbon is carbon that is stored in coastal habitats like salt marshes, mangroves, and seagrass beds.
Just like forests on land, coastal habitats capture and store carbon dioxide from the atmosphere, both in plants and in the soil. But compared to forests, coastal habitats do so on a much larger scale. Research shows that mangroves and salt marshes remove (sequester) carbon from the atmosphere at a rate 10 times greater than tropical forests. They also store three to five times more carbon per acre than tropical forests. This is because most coastal blue carbon is stored in the soil, rather than in above-ground plants.
Coastal blue carbon habitats are also sometimes referred to as “carbon sinks,” because they sequester more carbon than they release. They also hold on to it for long periods of time. Carbon found in coastal soils is often hundreds or thousands of years old.
The Role of Coastal Blue Carbon in Earth’s Climate
Carbon dioxide is a greenhouse gas created by burning fossil fuels like gasoline and coal, as well as solid waste and wood. Increasing levels of carbon dioxide and other greenhouse gases are a major driver of climate change.
Salt marshes, mangroves, and seagrass beds are incredibly efficient at sequestering and storing large quantities of carbon dioxide from the atmosphere. By doing so, these habitats can help decrease the effects of climate change.
When coastal blue carbon habitats are damaged or destroyed, however, their capacity to absorb carbon is lost. In addition, the carbon being stored in these habitats is released. This then increases the levels of carbon in the atmosphere. Coastal habitats around the world are being lost at a rapid rate, largely due to coastal development, meaning the large amounts of carbon they have stored is being released into the atmosphere.
Efforts to conserve coastal habitats play an important role in preserving coastal blue carbon, preventing the release of carbon into the atmosphere, and reducing the effects of climate change. Conservation efforts also protect the many other benefits that healthy coastal habitats provide, such as recreational opportunities, flood protection, and more.