Mapping global threats to seagrass meadows reveals opportunities for conservation

Abstract Numerous global maps chart humanities impact on multiple levels of biodiversity, revealing a multitude of pressures across a variety of ecological systems. While useful for identifying the global scale policy changes needed to conserve the world’s biodiversity, they often lack resolution at the scale needed for local management and conservation. While we can broadly speculate the key large-scale drivers that have influenced seagrass populations over the last century, no global map exists that reveals the range and scale of human pressures on seagrass meadows. Using a citizen science database ( https://seagrassspotter.org ) that comprises of more than 8000 georeferenced points, we use a subset of these map the prevalence of multiple, locally observed anthropogenic threats to seagrass meadows. We find that 50% of human-impacted sites were within areas with designated protection, reflecting 4.4% of the world’s marine protected areas and other effective area-based conservation measures where anthropogenic activities place seagrass at risk. Using vulnerability scores for each human impact, we identify high-risk sites in Columbia, Fiji, Indonesia, Mexico, Mozambique, the Philippines, Sri Lanka, and Tanzania, where multiple pressures likely place seagrass meadows on a trajectory of decline. In doing so, we build on a growing body of research highlighting the vulnerability of coastal ecosystems to human impacts, and at the same time, highlight the role of citizen science in identifying and mapping these threats at the resolution needed for management.