Bahamas-wide Seagrass Blue Carbon Assessment leveraging Modern Earth Observation Advances

Seagrasses offer multiple ecosystem services and play an important role in carbon-related climate change mitigation and adaptation. Their carbon sequestration and storage potential can support a variety of Multilateral Environmental Agreements like the Nationally Determined Contributions of the Paris Agreement and the Sustainable Development Goals. Spatially explicit knowledge of seagrass distribution and site-specific in-situ carbon data are both crucial for the assessment of the potential of seagrass blue carbon and its policy uptake in national climate agendas and investments. Within the context of the Global Seagrass Watch project, we analysed open big Sentinel-2 satellite data within the open cloud computing platform of the Google Earth Engine to quantify the extent of Bahamian seagrass, and their associated carbon stocks (Tier 2 Assessment), and sequestration rates. Preliminary assessments indicate that seagrasses cover about 10 to 25% of the country's shallow water area and may store up to 456 million Mg of carbon in their soils. of. The mapped seagrass extent is estimated to sequester 17 to 40 times more CO2 than the annual emissions of The Bahamas in 2018. Our generated data inventories underline the importance of the seagrass ecosystem for The Bahamas and the necessity of recognizing their seagrass blue carbon into national climate agendas. In parallel, our preliminary assessment showcases the need for more cost-effective conservation and restoration efforts for seagrass meadows. Our remote sensing approach and data could support holistic efforts of scientists, managers, policy makers, and companies, from a national to a global climate action context