Cambodia has passed a legislation to make the Tonle Sap Lake a biosphere reserve, which will protect it from development and exploitation of resources. The lake is southeast Asia's largest freshwater body. The biosphere programme of the United Nations Educational, Scientific and Cultural Organisation (unesco) had nominated Tonle Sap as a biosphere reserve in 1997. "But to put that into practice this legal framework was needed,' said Asier Segurola, unesco's programme officer