Researchers at Arizona State University have published the first high-resolution global map of seagrass, an ecosystem that stores an estimated 640 teragrams of carbon in the top 30 centimeters of sediment. That is roughly equal to the yearly emissions of 500 million cars. The map, created using AI trained on satellite images and diver-verified data, shows seagrass covers specific coastal areas with nearly 70 percent concentrated in just five countries: the US, the Bahamas, Cuba, Australia, and Indonesia. Between 2019 and 2024, the study found about 4 percent of global seagrass was lost, with human activities like coastal development in China and fertilizer pollution in Florida as major drivers. However, the map also highlights recovery successes, such as a restoration project in South Bay near Los Angeles and improved water clarity in Cuba. Only 21 percent of seagrass lies within marine protected areas, and nearly 80 percent of the loss occurred outside those zones. Because seagrass grows faster than coral, targeted restoration could yield quicker results. The map is being integrated into the Allen Coral Atlas to support marine protected area planning, carbon market projects, and biodiversity conservation. This turns seagrass from a poorly measured ecosystem into a measurable climate asset.
