Quantification of sediment deposition in the Mekong Delta: an assessment of sedimentation in integrated Mangrove-Shrimp farms in the Mekong Delta, Vietnam

The Mekong Delta is under threat from natural and anthropogenic disruptions. With no action taken, the coastal parts of the delta could almost disappear by the end of this century due to relative sea level rise (RSLR). This study explores the potential of sedimentation-enhancing-strategies (SES), which could potentially save the Mekong Delta from drowning. By focusing on integrated mangrove shrimp systems, this study aims to quantify sediment accumulation and assess their effectiveness to function as SES and counter RSLR. Fieldwork conducted in Tra Vinh and Ca Mau provinces, Vietnam, involves monitoring eight mangrove shrimp systems over time to analyse sediment accumulation, composition, and deposition. Laboratory tests on accumulated sediments further delve into the sediment composition. The findings of this study contribute to a deeper understanding of sediment accumulation, dynamics, and composition within these systems. Moreover, the study estimates integrated mangrove-shrimp systems’ potential as SES for the entire Mekong Delta. Results indicate a high likelihood that these systems can effectively mitigate RSLR, observing pristine uncompacted sedimentation rates of 1.95 cm/30 days in Tra Vinh and 1.16 cm/30 days in Ca Mau. This could imply sedimentation accretion rates of about 24 and 14 cm/year in integrated mangrove shrimp systems in Tra Vinh and Ca Mau, respectively. Potentially, the current integrated mangrove shrimp areas could accumulate up to 30 million m3 of sediment annually.