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Millions of axolotls once lived in the giant lakes of Xochimilco and Chalco on which Mexico City was built. This is the only place where they exist.   The number of axolotls in the wild is not known. But the population has dropped from roughly 1,500 per square mile in 1998 to a mere 25 per square mile this year.

The axolotl’s decline began when Spanish conquerors started draining the lakes, which were further emptied over time to slake the thirst of one of the world’s largest and fastest-growing cities. In the 1970s, Lake Chalco was completely drained to prevent flooding. In the 1980s, Mexico City began pumping its wastewater into the few canals and lagoons that remained of Xochimilco.   In what may be the final blow, nonnative fish introduced into the canals are eating its lunch — and its babies.  About 20 years ago, African tilapia were introduced into Xochimilco in a misguided effort to create fisheries. They joined with Asian carp to dominate the ecosystem and eat the axolotl’s eggs and compete with it for food. The axolotl is also threatened by agrochemical runoff from nearby farms and treated wastewater from a Mexico City sewage plant.

Researchers say the axolotls could disappear in just five years.   Scientists are racing to save the foot-long salamander from extinction.  A pilot sanctuary is expected to open in the next three to six months.   Zambrano,  a biologist at the Autonomous University of Mexico, proposes up to 15 axolotl sanctuaries in Xochimilco’s canals, where scientists would insert some kind of barrier and clear the area of nonnative species.  Without carp, the water would clear, and plants the axolotl needs to breed could flourish again.

Veterinarian Erika Servin, who runs the Mexico City government’s axolotl program at Chapultepec Zoo, is studying the possibility of introducing axolotls from the lab into the canals. But more study is needed to make sure the process doesn’t lead to diseases and genetic problems from inbreeding.

Meanwhile, the axolotl population is burgeoning in laboratories, where scientists study its amazing traits, including the ability to completely re-grow lost limbs. Axolotls have played key roles in research on regeneration, embryology, fertilization and evolution.  The first laboratory axolotls were living specimens brought to Paris in the 1860s and given to the Jardin des Plantes. Many of the axolotls raised in laboratories and aquariums today are descendants of those animals.