The fishery resources of Cambodia, originating mainly from the Tonle Sap Lake, rank first in the world for their productivity and fourth for their total catch despite the small size of the country. The floodplains contribution to income, employment,. and food security is higher than in any other country. However the natural productivity of the Tonle Sap's floodplains is threatened if the flood pulse, the temporarily submerged habitats, and the migration routes of the Tonle Sap are not given attention. In relation to this, the influence of Built Structures, that modify the hydrology of the system, needs to be better assessed at the ecological and socioeconomic levels.