Abstract
Introduction High-resolution imaging of coral reefs is critical for understanding ecosystem dynamics and guiding conservation efforts yet monitoring these changes at ecologically relevant spatial and temporal scales remains challenging. Methods We present cm-scale benthic habitat maps for over 5 km 2 of coral reefs in Tumon Bay, Guam, for 2022 and 2024, before and after Category 4 Typhoon Mawar (May 2023). NASA Airborne Fluid Lensing data were combined with in-situ ground-truthing and citizen-science annotations from the NeMO-Net platform. NeMO-Net’s original CNN was modified to an Attentive Residual U-Net (ARU-Net) with an EfficientNet-B3 encoder, class-weighted loss, and attention gating to classify seven habitat classes at pixel (cm) scale, using only ~1% of the 2022 dataset for training. Results Our model achieved 88% overall pixel-scale accuracy across seven ecologically relevant benthic classes. Full-coverage habitat maps for 2022 and 2024 reveal a 59% decline in massive coral, a 35% decline in coral fore-reef, and a 105% increase in algal cover, providing spatially explicit evidence of Typhoon Mawar’s reef impact. Discussion Coupling Fluid Lensing imagery with the NeMO-Net citizen-science platform and a modified ARU-Net yields accurate cm-resolved habitat assessments from sparse labels, supporting timely evaluation of disturbance and restoration outcomes in complex shallow-water reef environments.