FEATURE - Milk Thirst Threatens Mexico's Rare Desert Oasis
Author: Robin Emmott
Farmers could dry up the warm water Cuatro Cienegas pools in northern Mexico by the end of the decade if they keep tapping underground water supplies to grow green alfalfa leaves to feed dairy cows, international biologists say.
"The turtles are dying, the fish will soon be gone," said Benigno Vasquez, a farmer turned activist striving to contain the proliferation of alfalfa in Coahuila state, near the border with Texas.
Prized by NASA researchers, the 170 cactus-ringed pools at Cuatro Cienegas contain fish, snails, turtles, bacteria and unique living rock structures that offer a glimpse of the life forms that flourished on earth 200 million years ago.
"Each pond is an island of marine life in the desert. We can think of them as Mexico's Galapagos," said Valeria Souza, a Mexican biologist leading an international group of scientists to pressure the Mexican government to protect Cuatro Cienegas.
The Galapagos archipelago off Ecuador is renowned for its array of endemic species which inspired 19th century scientist Charles Darwin's theory of evolution.
Cuatro Cienegas is home to rare rock structures, known as stromatolites, that were crucial for life on earth but became marooned when the sea retreated 100 million years ago.
"This small piece of rock made life possible," Souza said, holding up a stromatolite, an ancient colony of single-celled organisms. "It is a whole ecosystem in five millimeters and it is dying."
Stromatolites' ability to harness oxygen, carbon, nitrogen and sulfates in the atmosphere at a time when phosphates had yet to be released into the oceans allowed them to form the basis of all life, serving as a platform from which complex, multicellular plants and animals developed.
WORLD HERITAGE SITE
Scientists at NASA say understanding Cuatro Cienegas may help us know how the earth developed and hold clues to whether other planets like Mars have primitive, extraterrestrial life.
"We may also learn how earth could react to global warming. The range of water temperatures at the lagoons could allow for experiments to investigate how marine life can adapt to changing water temperatures and environments," said Jim Elser, a limnologist, or expert in the study of inland water, at Arizona State University, who has worked with NASA.
For now, saving the pools is the most urgent task. One lagoon dried out six months ago and was briefly replaced by wild flowers. Winter rains have refilled the shallow cobalt pool, but the stromatolites have not recovered, Souza said.
"Cuatro Cienegas is a biological world heritage site and we must protect it," said Jose Sarukhan, one of Mexico's most renowned biologists.
A loophole in Mexican legislation means anyone can dig a well and extract water in the Cuatro Cienegas area, which lies on a huge underground water table.
Scientists and locals in Cuatro Cienegas blame big dairy groups in the nearby city of Torreon, northern Mexico's main milk-producing center, for drilling wells to grow alfalfa and buying milk from producers who feed the crop to their cows.
Mexico's federal government and wealthy landowners deny Cuatro Cienegas is at risk. Oscar Munoz, an environment ministry official at Cuatro Cienegas, said he has monitored 13 lagoons since 2003 and registered no change in water levels.
Nevertheless, pressure on milk producers has forced Lala, Mexico's top milk producer, to shut down eight wells owned by the company's main shareholder, the Tricio family.
Lala spokesman Guillermo Maynez said the closures were "cautionary" and that the company would finance a study to see whether the wells were causing damage to Cuatro Cienegas.
Coahuila state's government is urging federal authorities to ban the opening of more wells but has no plans to prohibit alfalfa production.
"We can't just blame one person or one group. We can't just blame Lala. We need to wider find a solution to this problem," state