Cuatro Ciénegas
Encyclopedia
Cuatro Ciénegas is a city in the northern Mexican
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...

 state
States of Mexico
The United Mexican States is a federal republic formed by 32 federal entities .According to the Constitution of 1917, the states of the federation are free and sovereign. Each state has their own congress and constitution, while the Federal District has only limited autonomy with a local Congress...

 of Coahuila
Coahuila
Coahuila, formally Coahuila de Zaragoza , officially Estado Libre y Soberano de Coahuila de Zaragoza is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico...

. It stands at 26°59′N 102°03′W, at an average elevation of 740 metres above sea level. The city serves as the municipal seat for the surrounding municipality of the same name
Cuatrociénegas (municipality)
Cuatrociénegas is a one of the 38 municipalities of Coahuila, in north-eastern Mexico. The municipal seat lies at Cuatrociénegas de Carranza. The municipality covers an area of 7860.6 km².As of 2005, the municipality had a total population of 12,220....

.

It is located in the state's desert region (Región Desierto). Cuatro Ciénegas is Spanish
Spanish language
Spanish , also known as Castilian , is a Romance language in the Ibero-Romance group that evolved from several languages and dialects in central-northern Iberia around the 9th century and gradually spread with the expansion of the Kingdom of Castile into central and southern Iberia during the...

 for "four marsh
Marsh
In geography, a marsh, or morass, is a type of wetland that is subject to frequent or continuous flood. Typically the water is shallow and features grasses, rushes, reeds, typhas, sedges, other herbaceous plants, and moss....

es"; the name was chosen by the first settlers because of the natural springs in the vicinity that create extensive areas of wetland and lakes.

Several failed settlements were founded here prior to the successful establishment of a town by Antonio Cordero y Bustamante on 24 May 1800. The settlement's original name was Nuestra Señora de los Dolores y Cuatro Ciénegas, which was later changed to Villa Venustiano Carranza, before finally settling on its current name.

The city is formally known as Cuatro Ciénegas de Carranza, in honour of its most famous son:
Venustiano Carranza
Venustiano Carranza
Venustiano Carranza de la Garza, was one of the leaders of the Mexican Revolution. He ultimately became President of Mexico following the overthrow of the dictatorial Huerta regime in the summer of 1914 and during his administration the current constitution of Mexico was drafted...

, President of Mexico from 1915 to 1920, who was born there in 1859.

The municipality reported 12,154 inhabitants in the year 2000 census.

Cuatro Ciénegas Biosphere Reserve

Cuatro Ciénegas is an official Mexican biological reserve
Biosphere reserve
The Man and the Biosphere Programme of UNESCO was established in 1971 to promote interdisciplinary approaches to management, research and education in ecosystem conservation and sustainable use of natural resources.-Development:...

. The biological reserves are small ecosystems with unique fauna and flora that are highly protected by government authorities. Recently, NASA stated that the biological reserve of Cuatrociénegas could have strong links to discovering life on Mars
Mars
Mars is the fourth planet from the Sun in the Solar System. The planet is named after the Roman god of war, Mars. It is often described as the "Red Planet", as the iron oxide prevalent on its surface gives it a reddish appearance...

, since the adaptability of bioforms in the region was unique in the world. There are some 150 different plants and animals endemic to the valley and its surrounding mountains (e.g., Fouquieria shrevei and Terrapene coahuila), including some 30 aquatic species in the Reserve, eight of which are fish (e.g., Herichthys minckleyi).

Live stromatolite
Stromatolite
Stromatolites or stromatoliths are layered accretionary structures formed in shallow water by the trapping, binding and cementation of sedimentary grains by biofilms of microorganisms, especially cyanobacteria ....

s inhabit Cuatro Ciénegas' pools. These are cyanobacteria colonies, extinct in most of the world, linked to the origin of an oxygen rich atmosphere over 3 billion years ago. A tiny copepod
Copepod
Copepods are a group of small crustaceans found in the sea and nearly every freshwater habitat. Some species are planktonic , some are benthic , and some continental species may live in limno-terrestrial habitats and other wet terrestrial places, such as swamps, under leaf fall in wet forests,...

 crustacean
Crustacean
Crustaceans form a very large group of arthropods, usually treated as a subphylum, which includes such familiar animals as crabs, lobsters, crayfish, shrimp, krill and barnacles. The 50,000 described species range in size from Stygotantulus stocki at , to the Japanese spider crab with a leg span...

, Leptocaris stromatolicolus, is known only from the interstices of these stromatolites and bottom sediments in the saline pools.

The pools are an oligotroph
Oligotroph
An oligotroph is an organism that can live in an environment that offers very low levels of nutrients. They may be contrasted with copiotrophs, which prefer nutritionally rich environments...

ic environment with little available phosphate
Phosphate
A phosphate, an inorganic chemical, is a salt of phosphoric acid. In organic chemistry, a phosphate, or organophosphate, is an ester of phosphoric acid. Organic phosphates are important in biochemistry and biogeochemistry or ecology. Inorganic phosphates are mined to obtain phosphorus for use in...

, leading one local bacterial species, Bacillus coahuilensis
Bacillus coahuilensis
Bacillus coahuilensis is a rod-shaped, Gram-positive, motile, spore-forming bacterium. This species was isolated from water samples taken from a highly saline desert lagoon in Coahuila, Mexico....

, to acquire the genes necessary to partially replace its membrane phospholipid
Phospholipid
Phospholipids are a class of lipids that are a major component of all cell membranes as they can form lipid bilayers. Most phospholipids contain a diglyceride, a phosphate group, and a simple organic molecule such as choline; one exception to this rule is sphingomyelin, which is derived from...

s with sulfolipid
Sulfolipid
Sulfolipids are a class of lipids which possess a sulfur-containing functional group. One of the most common consituents of sulfolipids is sulfoquinovose, which is acylated to form sulfoquinovosyl diacylglycerols. In plants, sulfolipids are important intermediates in the sulfur cycle....

s through horizontal gene transfer
Horizontal gene transfer
Horizontal gene transfer , also lateral gene transfer , is any process in which an organism incorporates genetic material from another organism without being the offspring of that organism...

.

Several environmental conservation leaders are working to protect the valley, including Pronatura Noreste
Pronatura Noreste
Pronatura Noreste is a Mexican non-government, non-profit organization, recognized by the National Council of Science and Technology as a scientific and educational organization. Pronatura Noreste is one of six regional offices of the Pronatura family, and has its headquarters in Monterrey, Nuevo...

. The organization owns a private reserve, called Pozas Azules, and has several ongoing projects that include the protection of native species, including stromatolite
Stromatolite
Stromatolites or stromatoliths are layered accretionary structures formed in shallow water by the trapping, binding and cementation of sedimentary grains by biofilms of microorganisms, especially cyanobacteria ....

s and the eradication of invasive flora and fauna, as well as community development and water efficient agriculture combined with organic techniques.

Drying out?

Scientists working in the basin and some local residents claim to have observed reduced spring discharge and a decrease in surface water in the Cuatro Ciénegas Basin (CCB) in recent years, although these changes have not been well documented in the scientific literature. Some have blamed the possible drying out on changes in climate and others have ascribed it to the introduction of large scale agriculture in adjacent valleys over the past two decades.

Valeria Souza, an ecology professor and researcher at the National Autonomous University of Mexico, found that based on genetic studies of microbes in the CCB and surrounding valleys, the aquifer extends far beyond the CCB and includes adjacent valleys. She published her results in the Proceedings of the National Academy of Sciences in April 2006. Regarding the source of drying out, she wrote: "Similar to situations occurring with increasing frequency in various arid regions of the world, agricultural development and associated water extraction in the region have placed new pressures on the ecological integrity of the unique ecosystems of Cuatro Ciénegas."

Research by hydrogeologist Brad Wolaver at the University of Texas at Austin, now at Flinders University, also found evidence that the aquifer supplying the water that emerges at the surface of the Cuatro Ciénegas Basin extends far beyond the basin and thus is potentially impacted by agricultural water extraction in adjacent valleys.

External links

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