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Building Blue Carbon Projects
An Introductory Guide
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What is Blue Carbon?
The marine biosphere is a major component of the global carbon cycle, responsible for roughly
half of the annual photosynthetic absorption of the greenhouse gas (GHG) carbon dioxide (CO
2
)
from the atmosphere (Field
et al.
, 1998, adapted from Lutz
et al
., 2007).
Blue Carbon
is a concept
that describes the carbon linked to the marine biosphere through coastal and marine ecosystems.
These ecosystems aid in mitigating climate change by actively sequestering carbon from the
atmosphere and also by providing natural carbon storage in biomass and sediments. The Blue
Carbon concept is currently focused on three key coastal ecosystems: mangrove forests, saltwater
marshes, and seagrass meadows (Laffoley and Grimsditch 2009, Nellemann
et al
., 2009).
Coastal Blue Carbon ecosystems have been found to be highly efficient at storing and sequestering
carbon. Figure 1 illustrates where carbon is stored in Blue Carbon ecosystems: in plant biomass
and below the surface in sediments. The carbon-rich soils associated with Blue Carbon habitats
can represent significant carbon accumulation, with up to five times more carbon stored in these
soils than in the soils of terrestrial forests (Donato
et al
., 2011, Fourqurean
et al
., 2012).
In addition to Blue Carbon, coastal and marine ecosystems provide a wide range of other
important ecosystem services, such as climate change adaptation, water filtration, shoreline
stabilisation, storm and flood protection, sustaining biodiversity, and habitat provision for
commercially and recreationally important species of fish and shellfish, as well as iconic species.
Equally important, but complex to value monetarily, intact ecosystems provide recreational
benefits and have spiritual values for the local community as well as visitors. In general, they also
help sustain the livelihoods and cultural heritages of the communities that rely on healthy coastal
and marine ecosystems. The conservation of Blue Carbon ecosystems is significant to climate
change mitigation and adaptation strategies, will support overall ecosystem resiliency and help
sustain important ecosystem service values. It represents a comprehensive ecosystem approach to
management.
Key takeaways:
When healthy, Blue Carbon ecosystems store and sequester carbon helping to mitigate climate
change, help safeguard biodiversity, and are also vital to many coastal and island communities
through the numerous important ecosystem services they provide.
When degraded, Blue Carbon ecosystems contribute to climate change by releasing stored
greenhouse gases (GHG) into the atmosphere and providing fewer ecosystem services.
A Blue Carbon project aims to use the climate change mitigation value of marine and
coastal ecosystems to support their conservation, sustainable use, and restoration
