15:55 〜 16:10
[ACG51-08] Integrating Multiscale Modeling and Monitoring Approaches for Mangrove-Rich Coastal Systems in Data-Scarce Regions: A Case Study in Batan Bay, Philippines
キーワード：Mangroves , Philippines, Panay, Harmful Algal Blooms (HABs), COAWST, Restoration
Monitoring mangroves along tropical and subtropical coastlines—especially in deltas and intertidal zones—is inherently challenging due to their geographic isolation, the logistical complexities and high costs associated with long-term studies, and the difficulties in aligning conservation strategies with local community interests. In our study, we combine multiscale modeling, comprehensive field measurements, and long-term remote sensing to evaluate the ecological conditions in Batan Bay, Philippines. We hypothesize that nutrient inputs from river discharges and human activities (such as overfeeding in fishponds and the excessive use of artificial feeds in newly introduced milkfish cages) were once mitigated by the bay’s natural water exchange with the Sibuyan Sea but that this buffering capacity has diminished since 2015. Extensive field campaigns—including surveys in both active and abandoned fishponds following two harmful algal bloom events—allowed us to identify areas with alarmingly low dissolved oxygen levels (<2–3 mg/L). Moreover, observed warming trends and increasing seasonal precipitation differences (with wetter periods becoming even wetter and drier periods drier), supported by principal component and correlation analyses, reveal significant shifts in nutrient dynamics and water quality. Finally, we showcase an integrated approach that combines multiscale hydrodynamic modeling and sediment transport analyses within abandoned fishponds to evaluate current soil accumulation, thereby informing the selection of optimal management scenarios.