The Tonle Sap Lake as a productive ecosystem

The Tonle Sap Lake ecosystem is considered by many to be the prodigious source of sustenance of the lower Mekong River Basin. Its productivity is one of the principle arguments in the integrated water resources management (IWRM) process. The productivity is most conspicuous in the fish catches and the large number of livelihoods that are sustained. A review of the data that are widely used to quantify the Tonle Sap's productivity has shown that these are problematic and do not provide an unambiguous indication of the level of ecosystem productivity. Ecosystem productivity in IWRM in the Mekong River Basin has a more prominent role than in most other river basins, and the process is compromised by the use of inadequate indicators. A practical, integrated indicator for ecosystem productivity is proposed.