Monitoring aquaculture pond expansion as a driver of mangrove loss in coastal Asia

: Mangrove ecosystems provide essential services for biodiversity, coastal protection, and carbon sequestration, yet they remain under pressure due to the expansion of pond-based aquaculture. In this study, we quantify the direct contribution of pond aquaculture expansion to mangrove loss at large spatial and temporal scale using integrated Earth observation data from 1996 to 2019. We combine a continental-scale aquaculture pond time series derived from Landsat and Sentinel time series with mangrove extent data from the Global Mangrove Watch. To enable robust attribution despite uneven temporal sampling, we introduce a harmonized positional time-index framework that aligns pond activation with episodic mangrove observations. Mangrove loss is conservatively attributed to aquaculture when disappearance occurs at or shortly after pond activation. By overlaying and comparing these datasets at the country level, we identified instances of direct conversion and tracked changes over time. Our temporal analysis of pond-activation–attributed mangrove loss across twelve Asian countries reveals a highly regionalized pattern of aquaculture-driven mangrove conversion. The largest losses occurred during the early phase from 1996 to 2007, dominated by Indonesia (13,046 ha) and Myanmar (2,892 ha). Although losses declined after 2007 in most countries, Indonesia and Myanmar continued to experience substantial mangrove conversion during later periods, while other countries showed only minor changes after 2010. Spatial analyses identify clear hotspots where dense pond clusters coincide with historic mangrove degradation. Overall, our results on aquaculture-driven mangrove loss in Asia highlight a pronounced spatial concentration of mangrove conversion driven primarily by a few countries and distinct periods of intensified land-use change, particularly linked to aquaculture expansion. The proposed framework improves causal inference in multi-source satellite analyses and supports more informed coastal management and conservation strategies.