Cambodia’s Tonle Sap Great Lake is the largest freshwater floodplain lake in the world, increasing and decreasing in size annually from 3000 sq. km at the peak of the dry season in May to 12,000 sq. km in the wet season in October, and varying in depth from 1m to 14m over the same period. This annual flood cycle creates an incredibly productive environment for both wildlife and people. The seasonally inundated forest and scrub around the lake has been recognized since 1994 as the last breeding stronghold in Southeast Asia for a number of globally threatened large waterbirds, particularly pelicans, storks and ibis. Since early 2000, WCS has worked with the Cambodian Government to establish conservation activities in Prek Toal, one of three Core Areas of the Tonle Sap Biosphere Reserve. The project works to protect the waterbird colonies from egg and chick collection, and to gather baseline research and monitoring data on bird populations and breeding ecology.