The Global Seagrass Watch: Spatially-explicit seagrass ecosystem accounting enabled by contemporary remote sensing advances

Seagrasses provide globally significant yet underestimated ecosystem services to humans, economies and ecosystems, the so-called natural climate solutions. Climate change, eutrophication, coastal development and uneven protection levels are impacting the health and services of seagrasses. Contemporary approaches are needed to reverse this loss of our coastal natural capital. Ecosystem Accounting (EA) presents a new holistic approach to streamline physical and monetary evaluation for natural ecosystems. The conceptualization of the System of Environmental-Economic Accounting (SEEA) EA by the United Nations signals a new era of comprehensive solutions for the conservation, restoration and protection of ecosystems like seagrasses. Here we present the Global Seagrass Watch coastal EA framework. Our framework harnesses powerful cloud computing, globally aggregated public satellite and reference datasets, and AI-guided big data analytics to map the ecosystem extent, condition, and services of seagrasses, including their accuracies and uncertainties. We showcase recent national seagrass EA applications across largely-uncharted underwater biomes in more than 30 countries and 300,000 km2. We targeted these coastal biomes due to their vast blue carbon and coastal biodiversity stocks, lack of spatially explicit information, and uneven uptake in global funding and policy strategies. Our introduced EA system yet concerns only baseline mapping of seagrass biophysical stocks. In the next phase, we aim to integrate ecological and economic modelling, and spaceborne change detection into our scalable framework. This amalgamation of legacy and modern mapping, modelling, and variables could support spatially-explicit blue carbon accounting, policy making, financing, and, ultimately, coastal resilience within and beyond the 21st century