The exponential growth of human populations in the Mekong-South China Sea (SCS) system, the eutrophication of estuarine and coastal waters by excess nutrients transported by the Mekong River, and the rapid sinking of the Mekong Delta are fundamentally changing the biological productivity and biodiversity of the system, with uncertain implications these aquatic resources. In the near future, larger forcings will alter the linkages between the Mekong system and the SCS basin. The completion of 62 hydropower dams planned by 2030 along the Mekong and its major tributaries will dramatically reduce the mean, seasonal flow cycle (up to an order of magnitude) and sediment loading of the Mekong River. Less riverine input and sediment loading, especially in summer, will reduce the supply of nutrients and fresh water to the coastal ocean, and will decrease the vertical and lateral mixing in the basin. An assessment of the synergistic effects and interactions among these social and physical factors affecting land-sea exchange in the Mekong-SCS system, and the overall productivity of its aquatic ecosystems is currently lacking. We can predict and develop strategies to mitigate the outcomes of those changes only if we can address cross-scale social - ecosystem dynamics.
We have assembled a multidisciplinary team to address these dynamics through a combination of field research and numerical work also in collaboration with Vietnamese colleagues. We propose to:
a. Analyze data collected during a broad survey of the physical and biogeochemical processes at work in the Mekong Plume that took place in June 2016 under a sponsorship from the Schmidt Ocean Institute (SOI provides only ship time and does not fund any further research endeavor). The data from this cruise will provide a critical baseline for understanding future changes in the Mekong-SCS system.
b. Carry out numerical studies of the effect of flow alterations on the movement of water, and nutrients from land to sea, and to explore the impact of different land use and climate change scenarios on the Mekong-SCS system.