Global high-resolution mapping of seagrass to support conservation

Main Highlights

• Produced the first global 10 m resolution maps of seagrass ecosystems using 4.75 million Sentinel-2 satellite images and deep learning.
• Mapped 148,506 km² of seagrass worldwide, including both intertidal and subtidal habitats.
• Detected 5,969 km² of seagrass loss and 6,221 km² of degradation from dense to sparse cover between 2019–2024.
• Identified global seagrass hotspots and vulnerable regions to inform conservation, marine protection and climate policy.

Abstract

Seagrass ecosystems underpin coastal biodiversity1 and provide vital ecosystem services, including shoreline protection, food security and climate mitigation. Despite growing recognition as a nature-based climate solution, seagrasses are among the least mapped and most poorly understood vegetated coastal ecosystems. Here we present, to our knowledge, the first global 10-m spatial resolution maps and change analysis of seagrass extent in clear, shallow coastal waters, derived from 4.75 million Sentinel-2 MSI satellite images for two periods (2019–2020 and 2023–2024). Using a deep-learning classifier trained on curated reference data, we identified 148,506 km2 of seagrass globally, including 5,961 km2 of intertidal and 142,545 km2 of subtidal areas. Sixty-nine per cent of global seagrass extent is concentrated in The Bahamas, Cuba, the USA, Australia and Indonesia, yet only 21% of seagrass areas are located within marine-protected areas. Over the 4 years of the study, 5,969 km2 (4%) of seagrass was lost, and an additional 6,221 km2 (4.2%) was degraded from dense to sparse cover in tropical regions. Our findings identify seagrass meadow hotspots and vulnerable regions to inform conservation and climate policy.

Citation

Peng, J., Li, J., Krause, J.R. et al. Global high-resolution mapping of seagrass to support conservation. Nature 655, 663–669 (2026). https://doi.org/10.1038/s41586-026-10704-3