Researchers at Mexico’s National Autonomous University are taking an even more pioneering step. The goal is to monitor the rapidly declining population of the axolotl, an endangered salamander native only to the canals of Xochimilco. We’re bioremediating the waters of Xochimilco to locate residual traces of axolotl DNA. When deployed effectively, this technique can provide unique and important insights to aid in assessing the species’ status and informing its conservation.
The axolotl, or Mexican walking fish, has experienced severe population declines in recent decades. In fact, as recently as 1998, scientists had figured there were about 6,000 axolotls per square kilometer in their native habitat. In 2014 this number crashed down to just 36 per square kilometer. This shocking drop underscores a growing need to aggressively conserve a species that has long served as a bellwether for the nation’s environmental health.
Unique Habitat and Reproductive Potential
Today, Xochimilco is a UNESCO World Heritage site. It serves as the only natural habitat for the axolotl, letting this remarkable species flourish in its labyrinth of canals. This habitat is important not just for the axolotl, but for regional biodiversity as a whole. Reproductive prowess The axolotl lays 600-800 eggs at one time. Knowing that they can recover their populations if we take the right conservation actions provides us all hope.
Luis Zambrano, a biologist from the university’s ecological restoration lab, emphasizes the axolotl’s potential for recovery. He states, “The axolotl reproduces a lot because it lays a lot of eggs … it can easily recover and we know how.” This resilience is perhaps the most notable aspect of the axolotl, which has contributed to the current conservation efforts working to restore the axolotl’s numbers.
Innovative DNA Techniques
The scientists employ environmental DNA (eDNA) sampling techniques to identify genetic material. This approach is allowing them to start figuring out what organisms are shedding DNA into their surroundings. Where traditional sampling methods with nets have gone empty during periodic surveys, researchers are taking to this special technique. As Zambrano explains, we’re all depositing DNA everywhere we go. This DNA can best be protected by literally filtering down the air or water we may be breathing around us. Once established, this acoustical method can even show the presence of axolotls without having to physically catch them.
The team of British scientists conducts comparisons between the filtered DNA samples and profiles stored in a genetic library they’ve created. By uniting their expertise, this collaboration will help improve understanding of the axolotl’s distribution and bring about more targeted conservation efforts.
Collaborative Conservation Efforts
Since 2023, Conservation International Mexico has collaborated with Zambrano on the conservation of the axolotl. Their combined actions work toward both saving this endangered species and restoring water quality in Xochimilco. Improved water quality not only supports axolotls but increases locally important species like pollinators. All of these individual changes contribute to a more vibrant ecosystem as a whole.
To date, scientists have only been able to survey a third of Xochimilco with the eDNA method and old-fashioned net work. As they explore deeper, they hope to learn more about the axolotl’s habitat and needs. As their work evolves, so does their mission to create more sustainable practices that bring benefits to both wildlife and their neighboring communities.