Donate Take Action

Join us


Marine Places

Sian Ka’an Biosphere Reserve

Stretching for 75 miles (120 km) along Mexico’s Caribbean coast, the Sian Ka’an Biosphere Reserve contains a mixture of mangrove swamps, lagoons, and freshwater marshes; it was declared a World Heritage Site by UNESCO in 1987. The mangroves are protected from the energy of the Caribbean Sea by a barrier reef growing along the coast. However, the reserve’s terrestrial part is between 20 and 75 percent flooded, depending on season. Sian Ka’an’s mangrove systems are some of the most biologically productive in the world and their health is critical for the survival of many species in the western Caribbean region. Hidden between the massive mangrove roots live oysters, sponges, sea squirts, sea anemones, hydroids, and crustaceans. Bird species found here include roseate spoonbills, pelicans, greater flamingos, jabiru storks, and 15 species of heron. The swamps are also home to West Indian manatees and two endangered crocodiles: the American crocodile and Morelet’s crocodile. The explosion of tourism in the nearby resort of Cancún poses several threats to the area. Unregulated development has increased pollution and altered the distribution and use of water in Sian Ka’an, compromising the health of the mangroves.

Sian Ka’an Biosphere Reservezoom image
  • Atlantic Ocean West
  • Principal Species Red, black, white, and button Mangroves
  • Area 400 square miles (1,000 square km)
  • Location Eastern coast of Yucatán Peninsula, eastern Mexico, 90 miles (150 km) south of Cancún
Sian Ka’an Biosphere Reserve habitat mapzoom image