Many of Australia's ecoregions, and the species within those regions, are threatened by human activities and introduced animal, chromistan, fungal and plant species. All these factors have led to Australia's having the highest mammal extinction rate of any country in the world. The federal ''Environment Protection and Biodiversity Conservation Act 1999'' is the legal framework for the protection of threatened species. Numerous protected areas have been created under the National Strategy for the Conservation of Australia's Biological Diversity to protect and preserve unique ecosystems; 65 wetlands are listed under the Ramsar Convention, and 16 natural World Heritage Sites have been established. Australia was ranked 21st out of 178 countries in the world on the 2018 Environmental Performance Index. There are more than 1,800 animals and plants on Australia's threatened species list, including more than 500 animals.