Turquoise pools, streams and freshwater springs sparkle among the gypsum dunes and dried lake beds of the Chihuahuan Desert in Mexico.
A mirage? No, it is the Cuatro Ciénegas (Four Mashes) Basin Wildlife Refuge, a roughly 500-square mile site located in north-central Mexico. Decreed a natural refuge by the Mexican government in 1994, Cuatro Ciénegas is The Nature Conservancy’s first land acquisition in Mexico.
An extreme rarity, Cuatro Ciénegas is one of only two remaining desert spring-fed wetlands in North America. The other is Ash Meadows National Wildlife Refuge in Nevada, which the Conservancy also helped save.
Where there is water, so there are fish-in the lakes (lagunas), the pools (pozas) and the canals. Many of the pozas are natural aquariums, containing only a few hundred gallons of water; even the larger lagunas are seldom more than 250 ft. wide or 25 ft. deep. The area’s salt marshes are alive with snakes, turtles, and fish.
Cuatro Ciénegas has 77 unique native plant and animal species, including the threatened Coahuilan box turtle, grass shrimp and a variety of desert fish, including the threatened Coahuilan (Banded) pupfish, Cyprinodon atrorus, which can withstand conditions of especially high temperatures and salinity, and two varieties of Cichlasoma minckleyi.
Naturalists have long expressed concern about the future of Cuatro Ciénegas, citing the falling water table (due to the pumping of aquifers for irrigation) and continued mining of the natural gypsum dunes, along with overgrazing and uncontrolled tourism.
“We still don’t understand the [dune formation] process very well,” states Salvador Contreras Banderas, a biologist with the Autonomous University of Nuevo Leon (UANL). “In fact, we keep learning about the biology and geology of this region. New species are continually discovered in the valley,” even as others are documented as becoming extinct.
“What we’ve seen is that the water has been over-exploited,” Contraras said. “The seasonal rhythms of the marshes are being overridden by human development, and the dunes are steadily being destroyed.” Mining has reduced the once 50-foot gypsum dunes to 20 feet. Recently, however, due to extensive efforts by environmentalists and others, mining has been halted.
Working with local partner DESUVALLE, The Nature Conservancy has protected a 450-acre site called La Poza Azul, so named for the turquoise pools found there. Unfortunately, in previous years the refuge as a whole had not been afforded the conservation protection it needed, but this is changing.
The Conservancy”s Mexico program, Texas chapter, DESUVALLE and other partners are initiating a number of conservation projects at studying Cuatro Ciénegas, including studies of hydrology, environmental impact studies and the establishment of environmental education programs. At La Poza Azul, conservationists recently created a new visitors center to educate visitors about this true oasis in the desert.
References
Aristy, Natalie, “Buying a Mexican Oasis,” Nature Conservancy, May/June 1998, p. 28.
Grall, George, “Mexico’s Desert Aquarium,” National Geographic Magazine, October 1995, pp. 85-97.
Mader, Ron, “Endangered Treasure: Cuatrocienegas,” October 1993, http:www.txinfinet.com/mader/
exotravel/border/cienegas1.html.
— GCKA Newsletter, August 1998