A multi-source, remote sensing-driven framework for detecting structural and compositional change in coral reefs

Coral reefs are experiencing unprecedented change due to climate-driven disturbances, yet effective monitoring remains constrained by limited integration across data types and spatial scales. This study presents a multi-source framework for detecting structural and compositional changes in coral reefs by integrating ICESat-2–derived terrain metrics, high-resolution PlanetScope imagery, and field-based photoquadrat observations. We applied this workflow to Heron Reef in the southern Great Barrier Reef, Australia, to quantify changes between 2020 and 2025—a period marked by 3 mass bleaching events and 9 cyclones. ICESat-2 data provided rugosity, slope, and bathymetric depth, while spectral unmixing of PlanetScope imagery yielded subpixel estimates of benthic composition. Satellite derived bathymetry (SDB) was validated against ICESat-2 depths using a random forest regression (RMSE: 0 . 30 − 0 . 32 m). Temporal changes were quantified per pixel, filtered by uncertainty thresholds from the Special Law of Propagation of Variances (SLOPOV), and analyzed for spatial clustering using Moran’s I. Results revealed structural and compositional shifts concentrated along the reef crest, with increases in rugosity and slope indicating potential recovery in some areas, while decreases suggested localized degradation. Coral cover declined modestly (55.4% to 53.8%), though spatial patterns were highly heterogeneous. While this framework enables broad-scale monitoring, it operates within the inherent uncertainties of large-area remote sensing, emphasizing the need for further in situ validation and application across diverse reef systems. This integrated workflow demonstrates a scalable, repeatable approach for comprehensive reef monitoring that leverages openly accessible satellite data and provides actionable insights for conservation management.