Posted on behalf of Ana Belluscio.
Time is running out for a unique oasis of biodiversity in Mexico’s Cuatro Ciénegas basin. Researchers say that an extensive network of springs, streams and ponds in the Chihuahuan desert in northern Mexico is disappearing much faster than they had expected.
On a research expedition earlier this month, the researchers found that roughly one-third of the 300 ponds, including one of the biggest, El Churince, had dried up. And with them went two endemic fish species, the Cuatrociénegas shiner (Cyprinella xanthicara) and the Cuatrocienégas gambusia (Gambusia longispinis), as well the native Mexican Tetra (Astyanax mexicanus), says Evan Carson, a biologist at the University of New Mexico, Albuquerque, who studies the region. Two endemic aquatic snail species, Mexipyrgus churinceanus and Mexithauma quadripaludium, may have also been lost.
Stromatolites living in the ponds have also been destroyed. The last samples of these mats of bacteria and microorganisms, similar to some of the earliest life on Earth, were collected in May by molecular biologist Valeria Souza, from the National Autonomous University of Mexico. They are now sitting in Souza’s laboratory, waiting to have their genes sequenced.
The devastation is being caused by groundwater extraction from Cuatro Ciénegas, and from nearby valleys, mostly to grow alfalfa to feed dairy cows, placing severe strain on the water table. According to an official report from the National Water Commission, 49 million cubic metres of water are extracted each year, while the aquifer only recharges at a rate of 25 million cubic meters per year. “We have now lost approximately 30% of the basin, and the projection is that in two more years the rest disappears, as deep underground water is not flowing anymore”, says Souza.
The Cuatro Ciénegas basin is a unique environment where traces of an ancient past were still available for study, but with the loss of water it is rapidly degrading. Souza has been trying to preserve what she can, by finding and commercializing useful genes from organisms in the area, then sharing the profits with local people to give them a reason to help conserve the environment. “We are going to extensively study the remaining samples to understand what we just lost. We hope the samples we saved may provide a hint on how the planet endured climate catastrophes and perhaps help us understand how to survive global climate change occurring today,” says Souza.
Image: El Oasis de la Poza de la Becerra in Cuatro Ciénegas courtesy of Christian Frausto Bernal via Flickr under Creative Commons.