Blue Carbon Stocks in Seagrass Meadows – SEAME

SEAME aims at assessing the overall distribution and carbon storage capacity of seagrass meadows in Norway.



Seagrasses are aquatic flowering plants, whose name came from the grass-like morphology of most of their representatives. They are often confused with seaweeds, but are actually more closely related to the terrestrial flowering plants. Seagrass meadows have occupied coastal environments over millions of years and they form an ecological group with ~60 species across the globe. Seagrasses help keep the oceans and coastlines healthy by providing food and habitat for juvenile fish, protecting shorelines from erosion and filtering pollution from the water.

As any other photosynthetic organism, seagrasses fix carbon dioxide using the energy provided by light and transform it into organic carbon to sustain seagrass growth and biomass. They also store a significant amount of carbon in the sediment over long periods, capturing 2-4 times more carbon than terrestrial tropical rainforests, making them one of the most effective sinks on the planet. Recent studies estimate that seagrass meadows, along with tidal marshes and mangrove forests, are responsible for storing up to 70% of the carbon sequestered in the marine environment.

In Norway, Zostera marina is considered to be the most common species, found all along the Norwegian Atlantic and Skaggerak coasts, from the northernmost county, Finnmark, to Oslofjorden. There are records of seagrass meadows that were first registered over 100 years ago, indicating long-lived stands in stable conditions.



SEAME has partnered with scientists from the University of Oslo to conduct the following activities:
• Determine the total extent of seagrasses around Norway and the potential loss throughout the years.
• Calculate the carbon storage capacity of seagrasses in several locations around the Skagerrak coast.
• Provide an estimate of the total carbon stocks of seagrass meadows in Norway.


Photos from the project, click to view large:

Project timeline

March 2017

Seagrass distribution data

July 2017

Test sampling in Drøbak, Oslofjord

August 2017

Sampling at multiple locations around the Skagerrak coast

December 2017

Sediment analysis for organic material, C:N, carbon isotopes and radioisotopes dating

For more information

Maria Potouroglou, GRID-Arendal.