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Carbon Voice Curriculum


Blue Carbon Ecosystem

Sub-Unit 1
Image by Ammar ElAmir

What Is Blue Carbon Ecosystem?

Have you ever heard about blue carbon?
Even if you answered no, you actually might know more than you realize.

Blue carbon is simply the term for carbon that is stored and sequestered by marine and coastal ecosystems. The carbon that we, humans, are producing from our activities every day.

(Please check out unit 1 to learn more about how human activities contribute to producing more atmospheric carbon or greenhouse gas emissions.)

As mentioned in unit 2, our oceans provide a natural way of absorbing heat and reducing carbon emissions from the atmosphere. But, how? Well, it’s blue carbon ecosystems that do the job.


Marine and coastal ecosystems such as mangroves, seagrasses, salt marshes, and seaweeds are considered a part of the blue carbon ecosystem.

These ecosystems can “capture and hold” carbon, acting as something called a “carbon sink”.


Most of the carbon taken up by these ecosystems is stored below ground where we can't see it*, but it is still there. The carbon found in coastal soil is often thousands of years old! Blue carbon ecosystems can store up to 10 times more carbon than terrestrial forests. No wonder they play a critical role in addressing the climate crisis.

*Except for seaweed, which stores carbon in its tissues.

Oh! We almost forgot to mention coral reefs. They play an important role in improving air quality and provide an important ecosystem for life underwater. Additionally, they protect coastal areas and provide a crucial source of income for millions of people.

Image by Francesco Ungaro
Image by Jeremy Bezanger

When these ecosystems are damaged, an enormous amount of carbon is emitted back into the atmosphere, where it can then contribute to climate change.


So, protecting and restoring coastal habitats is a good way to slow the climate crisis. Also, any coastal ecosystems or habitat loss can lead to a range of adverse impacts on the long-term health of the marine and coastal environment.

When we protect the carbon in marine and coastal ecosystems, we protect healthy marine and coastal environments that provide many other benefits to people, such as recreational opportunities, storm protection, and nursery habitat for commercial and recreational fisheries.

Now, let’s dive more deeply into each of the ecosystems so that we know what to do to protect, conserve and restore them!

Image by Maxwell Ridgeway

Mangroves: The Coasts Guardians