Other effective area-based conservation measures (OECMs) are sites outside of protected areas that are governed and managed in ways that deliver the long-term in situ conservation of biodiversity. As of March 2023, 856 such sites have been reported to the World Database on Other Effective Area-based Conservation Measures, managed by the UN Environment Programme World Conservation Monitoring Centre. OECMs cover 1,992,729 km2 (769,397 sq mi) of the Earth's surface, accounting for 1,589,090 km2 (613,550 sq mi) on land and 403,639 km2 (155,846 sq mi) in the ocean.[1]