Dams in the upper Mekong River modify nutrient bioavailability downstream
The number of hydropower dams has increased dramatically in the last 100 years for energy supply, climate change mitigation, and economic development. However, recent studies have overwhelmingly stressed the negative consequences of dam construction. Notably, it is commonly assumed that reservoirs retain nutrients, and this nutrient reduction significantly reduces primary productivity, fishery catches and food security downstream. Such perception largely hampers electricity supply and even sustainable socio-economic development in many developing regions such as the Congo and lower Mekong basins.
However, solid scientific support for the widespread belief that dams retain nutrients is usually lacking, because monitoring programs gathering data to establish how nutrient fluxes and phytoplankton production have changed after dam construction are rare. A new article by Qiuwen Chen and his research group at Nanjing Hydraulic Research Institute, China, together with Prof. Jef Huisman from the University of Amsterdam and Prof. Stephen C Maberly from UK Centre for Ecology & Hydrology now provides extensive monitoring data for the upper Mekong River. Their data reveal some surprising new insights.
Science China Press
