Mangrove Ecosystem Health Index (MEHI): a new method to evaluate mangrove ecosystem health at landscape scale using spatial metrics, canopy density, and potential disturbance based on hexagonal grid

Mangrove ecosystems are critical for coastal resilience, biodiversity, and carbon sequestration, yet remain vulnerable to fragmentation, invasive species, and anthropogenic pressures. To address the need for more precise monitoring tools, this study introduces the Lagoon Mangrove Ecosystem Health Index (MEHI/HEMI), which integrates the Enhanced Mangrove Index (EMI), hexagonal grid-based spatial metrics, and anthropogenic disturbance indices. Validated in Segara Anakan, Cilacap, Indonesia, the MEHI was benchmarked against field observations and compared with existing indices. Results demonstrate that MEHI achieved an overall accuracy of 90.91% with a Kappa coefficient of 0.87, significantly outperforming (P < 0.05) the Mangrove Quality Index (MQI: 78%, Kappa = 0.70) and the Mangrove Vegetation Index (MVI: 82%, Kappa = 0.75). Spatial patterns revealed severe degradation in the western lagoon due to invasive species and human activity, while the eastern zone exhibited stronger ecological integrity supported by community-led conservation, notably the Simanja Ecotourism initiative. By delivering higher diagnostic accuracy and clear classification into Poor, Moderate, and Excellent categories, MEHI provides actionable insights for targeted restoration, conservation prioritization, and integration into national monitoring frameworks. This study advances mangrove health assessment by combining remote sensing diagnostics with participatory management perspectives, offering a scalable and policy-relevant approach to sustaining coastal ecosystems under increasing environmental pressures.