Los Petenes-Ría Celestún

Description

The ecoregion of "Los Petenes-Ría Celestún" forms a coastal corridor of wetlands in excellent state of preservation. This system forms a unique biogeographical area in Mexico, of great ecological value for its large faunistic and floristic diversity.

This region is a mosaic of mudflats, known locally as blanquizales, mixed with mangroves, cattails, reeds, low deciduous forest, low flooded forest, petenes of mangrove and rainforest, medium sub perennial rainforest and coastal dune scrub. This diversity of ecosystems maintains a faunistic diversity representative of the region, among which its avifauna is specially notice worthy, as it is represented by 304 species of birds among residents and migrants, coastal and marsh birds, such as herons (Ardeidae), ducks (Anatidae), gulls (Laridae) and a wealth of migratory songbird species (Passerines) and shorebirds that depart from the neighboring countries to the north of the continent, namely the United States and Canada, during their winter migratory flights.

The flora is represented by species of Central American and Caribbean affinity.

The geologic substrate on which these wetlands are situated corresponds to a karstic limestone, formed during Tertiary and Quaternary epochs, and which represents the youngest portion of the Yucatan Platform on the northern half of the Peninsula. Cenotes or dolines and fresh water spring form on this substrate.

The climate is tropical sub humid, with summer rains, which total near to 800 mm of rainfall; the average temperature is of the order of 26°C.

It should be pointed out that the estuaries of Ría Celestún are constituted by a very shallow hyper saline estuary that promotes water evaporation, and favors the presence of Brine Shrimp (Artemia salina) and Pink Flamingo (Phoenicopterus ruber), which feed upon these shrimp, in what represents their resting, feeding and breeding area, hosting a population estimated at close to 23,000 individuals.

These estuaries have been formed by the accumulation and deposition of sand deposited by oceanic currents. In the area of Los Petenes BR their peculiar plant communities known as petenes, islands of vegetation immersed in a matrix of shallow, muddy, brackish marshes, are particularly notice worthy. The surrounding fresh water springs, which nourish them, give origin to these islands that present the aspect of a ring-shaped rainforest. These plant communities result of special interest as they are only found in the Yucatan Peninsula, Florida and Cuba.

The petenes are dependant on the amount of fresh water, the type of soil and the micro topography, giving rise to plant associations such as mangroves, and including samples of low flooded rainforest and tall rainforest.

The type of soil plays a very important role in the distribution of the vegetation in the ecoregion of the Petenes-Ria Celestun, as the calcareous rock allows that filtrations of fresh water, originating in water-bearing formations, to surface inside the salt marsh, giving rise occasionally to cenotes, and promoting the presence of species of fresh-water hydrophytes interspersed in the salty water. This fact promotes the development of vegetation that constitutes a mosaic of different plant associations along the land-sea gradient.

Justification of Outstanding Universal Value

(ix): The ecoregion of Los Petenes-Ria Celestun offers conditions for the survival of a diversity of species of plants and animals throughout the year. During the dry season (from March to May) an endangered species, the Jabiru Stork (Jabiru mycteria) and other resident species are breeding, and this period extends until the arrival of the rains. It is an area of passage for migratory birds, some of which remain in the area. During the rainy season (from June to October), Flamingoe are breeding; during the season of "nortes" (strong winds blowing from the north) herons and cormorants breed, and once again, one observes the passage of migratory birds and the permanence of some of them.

More than 300 species of birds have been seen in the area: cardinals, orioles, motmots, woodpeckers, hummingbirds, weaver-birds (Icteridae), kingfishers, cormorants, frigate birds, herons, storks, ibices, osprey, hawks, vultures, owls, pelicans, shorebirds, gulls, among others, such as the Pink Flamingo (Phoenicopterus ruber ruber). This species uses the area as a nesting, resting, feeding and breeding site, with a population of 23, 000 individuals, from the total of 28, 000 estimated for the Yucatan Peninsula, and which, according to data provided by Wetlands International (2002), represents more than 75% of the biogeographical population for this species.

Along this wetlands corridor, in low depth areas, one finds manati (Trichechus manatus manatus), as this ecosystem provides feeding and protection areas for the species. The manati contributes to the ecosystem by recycling nutrients, and positively influences the fertility and productivity of the region by promoting the development of natural populations of plants and animals, among them some of economic interest for humans.

The area offers a uniquely scenic landscape by combining flora and fauna representative of the dry tropics with impressive islands of tropical rainforest, developing around a water spring or a cenote of fresh water immersed in a tropical savanna flooded with brackish water, where one may detect exotic species of palm trees, cacti, bromeliads and orchids, cataloged among the most beautiful of the continent.

(x): The ecosystem of petenes is considered as unique at the national level and throughout the world, as it is only located in the Peninsula of Florida in the United States and in Cuba. The World-Wide Fund for Nature considers it as the Ecoregion of "Petenes de Mangle" (Petenes mangroves NT1428), as it contains populations of four of the mangrove species present on the American Continent: Rhizophora mangle, Avicennia germinans, Laguncularia racemosa and Conocarpus erectus. This last species has the highest population reported for the State of Campeche and possibly for all of the Gulf of Mexico and the Mexican Caribbean.

In these sub-tidal marine beds one finds the most extensive and vigorous area of sea grasses registered for the Gulf of Mexico and the Mexican Caribbean, which together with the mangroves, represent protection, feeding, breeding and rearing sites for the aquatic fauna of the region. Among the more than 61 species of fish registered, species of commercial value stand out, such as the Hogfish or boquinete in Spanish (Lachnolaimus maximus), the Spanish mackerel or sierra (Scomberomorus maculatus) and the Common snook or robalo (Centropomus undecimalis). Furthermore, the site contains karstic systems and other underground hydrological systems, key to the ecological characterization of the area, as their conformation propitiates the development of the petenes.

Celestun is considered the fourth largest duck wintering area in the region of the Gulf of Mexico. During winter it is possible to see up to 13 species of migratory ducks. The flamingo is one of its more graceful and spectacular birds, but it also depends for its survival on a fragile ecosystem - the hyper saline lagoons. It prefers the more protected areas of the rías (estuaries) or coastal lagoons with high salinity, shallow waters and muddy soils, where the Brine Shrimp (Artemia salina) reproduce. This crustacean constitutes their main food-source and gives their feathers its characteristic pink coloration.

Four species of turtles nest on local beaches: the Atlantic Green Sea Turtle (Chelonia m. mydas), the Atlantic Loggerhead (Caretta c. caretta), the Hawksbill (Eretmochelys imbricata), and the Leatherback (Dermochelys coriacea).

The two species of crocodile found in Mexico are also present in this ecoregion: the American Crocodile (Crocodylus acutus) and Morelet´s Crocodile (Crocodylus moreletii).

Also, there are 45 species endemic to the Yucatan Peninsula, such as the Yucatan Black-throated Bobwhite (Colinus nigrogularis), the Mexican Sheartail (Doricha eliza), and the Yucatan Wren (Campylorhynchus yucatanicus).

Last but not least, the Horse-shoe crab or cacerolita (Limulus polyphemus), a marine arthropod considered a living fossil, is distributed from the coasts of the Yucatan Peninsula to Isla del Carmen, in the State of Campeche; it uses the sandy beaches and parts of the estuary next to the rías for breeding purposes.

Statements of authenticity and/or integrity

Los Petenes and Ria Celestun were decreed in 1999 and 2000 respectively, as Protected Natural Areas classified as of Biosphere Reserves. Applicable guidelines and regulations in terms of environmental and conservation matters are those prescribed by the General Law for Ecological Balance and Environmental Protection (LEGEEPA).

The Official Mexican Norm NOM-059-SEMARNAT-2001, whose purpose is to identify the species or populations of wild flora and fauna at risk in the Mexican Republic, and also to establish the criteria for inclusion or change in status for the species or populations by means of evaluation methods of their risk of extinction, is applied in these protected areas.

Likewise, both of these reserves have a Conservation and Management Plan published in the Official Diary of the Federation; for the Biosphere Reserve of Celestun in 2002 and under revision for the Biosphere Reserve of Los Petenes, in which the criteria and strategies to assure the conservation de the coastal ecosystems of the northwestern portion of the Yucatan Peninsula are considered.

Los Petenes and Ría Celestun have been listed as Ramsar sites since 2004, reason by which they are considered wetlands of international importance. Ria Celestun is also a MAB Biosphere Reserve into the MAB World Network.

Comparison with other similar properties

Coastal wetlands and their adjacent marine zones are considered one of the world's most productive environments, providing social and economic benefits of importance to people without lessening their importance as habitat for many species. These wetlands and coastal zones are important for their contribution to maintain the ecological processes and life support systems for human beings. Regrettably, they are also among the most threatened habitats in the world.

There are numerous properties on the World Heritage List with wetlands, and some of them show some similarities with the ecoregion of "Los Petenes-Ria Celestun", such as the following:

Everglades National Park, USA; it is an area of exceptional importance for conservation, as it includes a mangrove ecosystem, one of the most significant nesting areas of tropical birds, as well as providing habitat to species listed under some category of risk, including the manatee (Trichechus manatus). It is also important for its affluents of fresh water.

Doñana National Park, Spain: for having little disturbed marshes, and containing a long stretch of pristine coast and protecting one of the few remaining dune systems. It is a feeding and nesting area for flamingo (Phoenicopterus ruber).

Djoudj National Bird Sanctuary, Senegal; for supporting large waterbird colonies, harboring thousands of flamingo that reach the sanctuary, and for being habitat of threatened species such as the African Manatee.

Río Plátano Biosphere Reserve, Honduras; for including species considered in different categories of risk, such as the manatee (Trichechus manatus), crocodile (Crocodylus acutus), and sea turtles (Eretmochelys imbricata, Caretta caretta, Chelonia mydas, and Dermochelys coriacea).

Sian Ka'an Biosphere Reserve, Mexico; for being situated on top of a calcareous, partially emerged plain; having dwarf mangroves, peripheral mangroves, fresh and brackish water marshes, and an extensive set of cenotes; for being an area that includes the habitat of several endemic species.

Darien and Los Katios National Parks, Panama/Colombia; for presenting flooded plains, sandy beaches, rocky coasts, mangroves and swamps; there is also a large diversity of birds.

Arabian Oryx Sanctuary, Oman; for presenting beaches and coastal lagoons that provide habitat to colonies of resident and migratory birds, including gulls, terns, flamingos, herons and several species of ducks, all of which use the lagoon during winter; for presenting fresh and brackish water springs forming oasis of vegetation, which are used by a variety of birds, mammals and fish.