This freshwater marsh and partly saline wetland situated about 20 kilometres south of the city of Chennai serves as an aquatic buffer of the flood-prone Chennai and Chengalpattu districts. The diverse ecosystem of the marshland supports some 115 bird species, ten mammals, 21 reptiles, ten amphibians, 46 fish, nine molluscs, five crustaceans, and seven butterfly species. These include notable species such as Russell’s viper (Daboia siamensis) and birds such as the glossy ibis (Plegadis falcinellus), grey-headed lapwings (Vanellus cinereus) and Pheasant-tailed jacana (Hydrophasianus chirurgus). Apart from its biodiversity value, the wetland also plays a vital role in the prevention of flooding for the city of Chennai, soaking up water during wet periods and releasing it during dry spells. Inhabitants of seven surrounding villages partially depend on the wetland for their subsistence. The Site is threatened by invasive and non-native species, household sewage, urban wastewater and droughts. In response, the Conservation Authority of Pallikaranai Marsh is currently implementing a site-specific management plan.