Parque Nacional Arrecife Alacranes.02/02/08; Yucatán; 334,113 ha; 22°28´N 089°41´W. National Park. The most important coral formation in the Gulf of Mexico and one of the largest coral reefs of the country. It has five islands and supports a great biological diversity. The site is important for the preservation of germoplasm of endangered, endemic and useful species for humans. The conservation status of the coral reef is considered good, although the impact of human activities in the subaquatic medium is less known than in the terrestrial. It is BirdLife International Important Bird Area (IBA) for being the most important nesting site in the Gulf of Mexico for the bird species S. dactylatra, S. leucogaster, Sterna fuscata and Anous stolidus. In the sandy islands of Arrecife Alacranes, a great number of resident, migratory and occasional bird species have been registered. The site also supports four endangered species of marine turtles, threatened bird species Accipiter striatus, Falco peregrinus and Charadrius melodus and the coral species Plexaura homomalla, Plexaurelladichotoma, Acropora cervicornis and A. palmata. Until the 1940s, the Caribbean Monk Seal (Monachus tropicales) lived in this park but was exploited to extinction. The main threats the site faces are the presence of introduced species and the extraction of corals as souvenirs. The site has had a management plan since 2006. Ramsar site no. 1820.