What is blue carbon?

Discover why the protection and restoration of blue carbon ecosystems is essential for human wellbeing

4 min read

Seagrass underwater

What is blue carbon?

Marine ecosystems regulate the world's climate. They provide us with food and oxygen and they protect our coastlines from erosion. But they also capture and lock away carbon.
The term blue carbon refers to the carbon stored in coastal and marine ecosystems, such as:
  • mangroves
  • tidal and salt marshes
  • seagrasses.
These highly productive coastal ecosystems are particularly important for their capacity to store carbon within the plants and in the sediments below, creating very efficient carbon sinks.
Carbon sinks absorb more carbon from the atmosphere than they release, which could help to slow the rate of global heating. Examples of carbon sinks include forests and oceans.
Fishing boat anchored in the middle of the mangrove forest
Seagrass
Aerial view of salt marshes at Stiffkey, Norfolk, UKScott Davidson PR
 

Why is blue carbon so important?

Protecting, restoring and creating marine ecosystems that store blue carbon can help us mitigate climate change.
These natural carbon sinks sequester two to four times more carbon than equivalent forest habitats on land and as such are considered a key component of nature-based solutions to climate change.
Carbon sequestration is the process of capturing and storing atmospheric carbon dioxide.
Healthy blue carbon ecosystems also:
  • provide habitat for marine species'
  • support fish stocks and food security
  • sustain coastal communities and livelihoods
  • filter water flowing into our oceans and reef systems
  • protect coastlines from erosion and storm surges.
Blue Carbon Artist in Residence aims to strengthen links between city and sea
Seagrass
Image taken by @shanegrossphoto, courtesy of Climate Visuals, shows a SeaChange Society diver planting eelgrass into an area that historically had lush seagrass beds, but were wiped out due to human activity.
 

Why are blue carbon ecosystems under threat?

The main threats are largely driven by human activities, such as:
  • aquaculture (breeding, raising and harvesting fish, shellfish and aquatic plants)
  • farming and conversion of wetlands for agricultural use
  • use of fertilisers
  • dredging and bottom trawling
  • mangrove forest exploitation
  • unsustainable resource use
  • pollution
  • coastal development.
 

Protecting blue carbon marine ecosystems

measuring and monitoring seagrass biomass
At the University of Plymouth, we work to provide the evidence needed to protect marine ecosystems. Our world-leading researchers are implementing non-invasive approaches to monitoring seagrass meadows and carbon stocks, using marine autonomous technology, such as remote sensors, drones or satellite mapping.

We are at the cutting edge of developing social and economic research. It's needed to ensure that the value of our blue carbon stocks is accounted for. This will further investment in nature-based solutions.

Sian ReesDr Sian Rees
Associate Head of School - Research

We are studying the complex interactions between seagrass and flow in the ocean. And this helps us not only to identify locations where seagrass will increase or decrease the sequestration of carbon, but also allows us to construct high-resolution numerical models, that significantly improve our ability to predict habitat suitability.
This can greatly improve outcomes when attempting to restore blue carbon habitats. It can also help our understanding of carbon storage potential, under different physical environments.

Our long-term monitoring programme in Lyme Bay, has demonstrated how effective management protects and enables the recovery of marine ecosystems. It's led to new legislation, to protect hundreds of square kilometres of seabed from the damaging impacts of bottom-towed fishing gear.

Martin AttrillProfessor Martin Attrill
Professor of Marine Ecology

Using our world-class Coastal, Ocean and Sediment Transport (COAST) laboratory we worked alongside the Ocean Conservation Trust to improve the outcomes of seagrass restoration projects. We're pushing the boundaries in research to discover blue carbon habitats in the deepest parts of our ocean. So we can plan for their effective protection.
At Plymouth, we know that the protection and restoration of blue carbon ecosystems, is essential to protect human wellbeing. That's why we work at an international level to ensure that climate discussions include marine, that blue carbon stocks are protected, and habitats such as seagrass beds, are restored for future generations.

Discovering blue carbon potential

We are developing new transdisciplinary perspectives on blue carbon – benefitting restoration of natural habitats as well as social and economic wellbeing of coastal communities. This includes:
  • collaborating to develop enhanced solutions for seagrass monitoring
  • aiding the restoration of seagrass in Plymouth Sound
  • joining world experts to ask big questions about blue carbon
  • providing evidence to support policy-making processes.

Centre for Decarbonisation and Offshore Renewable Energy (C-DORE)

C-DORE brings together leading research and expertise from across the University. Through co-creation and collaboration with partners from business, government and key communities from across the globe, it aims to be a beacon for the University’s approach to solutions-oriented research, accelerating sustainable developments in decarbonisation and renewable energy.
In response to climate change imperatives, C-DORE’s work aligns to the UK Government’s Net Zero Strategy, British Energy Security Strategy and Clean Maritime Plan.
Centre for Decarbonisation and Offshore Renewable Energy