From Source to Sink: How Linking Upstream Fluvial Processes to Mangrove Sedimentation Can Improve Mangrove Management Strategies

Abstract

Although recent attention has been given to accelerated sea level rise (SLR), anthropogenic activity disrupts incoming flow and sediment critical to maintaining the mangrove ecosystem. Deforestation and conversion to agriculture and urban landscapes can increase sedimentation rates of mangroves. Excess sedimentation of mangroves causes upland species invasions, aerial root burial, and tree die-off. Conversely, dams and diversion of flow decrease the influx of sediment into mangroves and limits the effectiveness of mangroves to respond to SLR. Predicted increases in precipitation, erosion, and flooding due to climate change further exacerbates these issues, yet current hydrologic models do not fully incorporate the interrelations and amplification of these processes from anthropogenic activity and climate change. Despite significant literature of fluvial, coastal, and marine processes and their effects on mangroves, there is limited understanding of the complex integrations and interactions between these processes and their effect on mangrove sedimentation. Although improving, hydrometeorological monitoring is often spatially and temporally limited, therefore extracting mangrove sediment records can provide information on sediment accretion rates in relation to SLR. Additionally, hydrologic models, created primarily by and for temperate environments, often do not effectively model tropical processes, seasonal effects of rainfall, or compound fluvial and coastal flooding from tropical cyclones. The lack of integrated hydrologic model - ling and monitoring leaves local communities ill-prepared to make effective management decisions. Globally, to make significant advancement towards effective mangrove management, upstream river management is needed in addition to limitations on mass tourism, deforestation, and rapid development in areas hydrologically connected to the mangroves.