Location and General Description
The Ría Lagartos mangrove ecoregion streches along the coast on the east end of the Yucatan Peninsula facing Alabama, USA from across the Gulf of Mexico. These mangroves are bounded by calcareous deposits and limestone, which is the major soil formation in the area. The climate is sub-humid with little variation, and there are no relevant topographical features, as the whole area is fairly uniform.
Mangroves of both red (Rhizopora mangle) and black (Avicennia germinans) species, occur throughout the ecoregion, with the most striking feature being arboreal vegetation that has adapted to life in salt and briny water. Two types of mangrove inhabit this region: the pygmy mangrove, characterized by plants reaching no more than two meters in height and the fringe mangrove, in which trees reach almost ten meters in height. Both types grow in areas that are permanently flooded with various concentrations of salt water. The pygmy mangrove habitat also contains plants of the cyperaceae family. The distribution of mangroves in this area is not continuous, but rather intertwined with grasslands and occasional subtropical dry forests.
The adaptation of mangrove trees to salt water conditions has produced a unique habitat that enables many aquatic species to survive and reproduce. Ría Lagartos mangroves are the primary nesting site of flamingos (Phoenicopterus ruber) in Mexico (Arizmendi & Márquez - Valdelamar 2000). Approximately 280 species of aquatic birds also depend on the habitat provided by mangroves and their surroundings for feeding purposes including cormorant (Phalacrocorax spp.), wood stork (Mycteria americana), boat-billed heron (Cochlearius cochlearia), white egret (Egretta alba egretta), and snowy egret (Egretta thula). It has been estimated that over 300,000 aquatic birds use Ría Lagartos as migrating points or wintering grounds. The ichthyofauna of the region comprises 71 species of fish, some of them of great commercial value.
The area has been included within the Mexican Protected Natural Areas (PNA) network. Ría Lagartos was established as a PNA in 1979, and as a RAMSAR site in 1986. The key protected areas within the reserve are the mangroves, coastal dunes, subtropical forest, and the "Petenes", circular assemblages of trees that form a natural transition from dry to flooded habitats.
Types and Severity of Threats
Mangroves are being eliminated due to expansion of nearby towns. Although the effects of mangrove tree exploitation are less evident than in other locations within the area, habitat fragmentation and chemical contamination of water, as well as deforestation of mangrove trees for local uses, pose an enormous risk to the survival of the habitat and its ecological processes. The complexity of mangroves as a habitat, and their variety of ecological relationships, are in danger of deterioration due to habitat fragmentation and intensive exploitation. The number of fish and invertebrates in the mangroves has declined, and the Jabiru (Jabiru mycteria) has already disappeared from the reserve, although it is considered a species in danger of extinction (INE-SEMARNAP, 1999). Water flow in this mangrove ecoregion has been modified, and this could significantly alter the natural salinity regime, causing major disturbance, and ultimately extinction of animal and plant communities.
Justification of Ecoregion Delineation
Classification and linework for all mangrove ecoregions in Latin America and the Caribbean follow the results of a mangrove ecoregion workshop (1994) and subsequent report (Olson et al. 1996).
Arizmendi, C. y Márquez-Valdelamar, L. 2000. Areas de Importancia para la Conservación de las Aves en México. 440 pp. Fondo Mexicano para la Conservación de la Naturaleza, México.
Ecoregional Workshop: A Conservation Assessment of Mangrove Ecoregions of Latin America and the Caribbean. 1994. Washington D.C., World Wildlife Fund.
Frazier S., editor. 1999. A directory of wetlands of international ilmportance (designated under the RAMSAR Convention). Compiled by Wetlands International.
INE-SEMARNAP. 1999. Programa de Manejo Reserva de la Biosfera Ría Lagartos. 203 pp. SEMARNAP, México.
Mittermeier, R.A.; Myers, N; Robles-Gil, P.; y Goetsch, C. 1999. Biodiversidad Amenazada: Las ecorregiones terrestres prioritarias del mundo. CEMEX, y SIERRA MADRE, México.
Olson, D.M., E. Dinerstein, G. Cintrón, and P. Iolster. 1996. A conservation assessment of mangrove ecosystems of Latin America and the Caribbean. Final report for The Ford Foundation. World Wildlife Fund, Washington, D.C.
Prepared by: Alejandra Valero
Reviewed by: In process