The sun rises on Xochimilco. Before me, a landscape of canals and chinampas, artificial islands created for growing crops, unfolds. This was the form of agricultural production developed by ancient Mexicans from the lake area.
Pedro Méndez, a 45 year old peasant of dark complexion and sparkling eyes, leisurely rows towards his plot of land to show me his farming method (knowledge that has been passed down from generation to generation for at least 900 years). Nobody would imagine that we were only a few kilometers from Mexico City, a megalopolis that just today declared an environmental contingency plan restricting the use of two million cars and reducing industrial activity in the city by 40 percent in order to keep the inhabitants from suffocating.
In addition to pollution, traditional chinampa culture is also confronted by a variety of other challenges that continue to devour what remains of the wetlands well into the twenty first century. And the lives of not only peasants like Pedro, but also the existence of a group of species endemic to the region, depend on the future of this lake system.
The axolotl (Ambystoma mexicanum) stands out among these dependent species. The axolotl is a salamander larva that exists exclusively in these lakes; an amphibian that remains in an aquatic stage during its entire life cycle. Historically venerated by the Aztecs, the axolotl can breathe either through its lungs or epidermis and is able to regenerate its limbs. A subject of debate among European naturalists and a figure in 20th century Latin American literature, the axolotl is regarded as an ironic metaphor for Mexican identity in the book The Cage Of Melancholy by anthropologist Roger Bartra.
Despite its historical, biological, and cultural value, the axolotl is on the verge of extinction. It is a prospect that some people from Xochimilco feel imperils their own existence: “According to legend—says Pedro—when axolotls become extinct, we will disappear with them. This is what we believe. Our survival will depend on our ability to save the axolotl. [But] if we lose the axolotl, we will be lost as well.”
The Beginning of the End
As we navigate through a main canal, Pedro recounts that less than twenty years ago it was possible to catch 10 axolotls with a single throw of the net. For locals like him, axolotls not only represented an easy and abundant food source, but became a delicacy called mixmoli when cooked with tomato, chili, ashes and Montezuma Leopard Frogs (Lithobates montezumae, one of many forms of preparation. They were also wrapped in cornhusks and eaten on the lakeshore or used in a syrup as a cough remedy. But all this is in the past.
At present this paradise is threatened by the relentless advance of urban development. It is difficult to comprehend given its standing as a UNESCO World Heritage Site, a Natural Protected Area and one of the Ramsar Convention’s Wetlands of International Importance. It is even more baffling in light of the many environmental benefits it provides to its neighboring city—like mitigating noise and air pollution, supplying water and preventing differential ground subsidence, to mention just a few.
The chinampa is the fundamental unit within this complex agricultural framework. It is an ancestral farming system that gains ground over the lake’s surface. The units are built by layering aquatic vegetation and mud from the lake bed and are bounded by wooden stakes and trees. It is an artificial system of plots patiently constructed over centuries that transforms the lake into an agricultural area. The chinampa involves social organization and its functional principle lies in the water-earth-human interrelationship. The chinampa has been recognized by the Food and Agriculture Organization of the United Nations (FAO) as a Globally Important Agricultural Heritage System (GIAHS).
And, as regards this story, the chinampas are a key element in the axolotl’s conservation. The species finds not only a hospitable, well oxygenated body of water in which to feed and survive among the canals and aqueducts (known as apantles), but also a sanctuary in which to reproduce and thrive. In exchange, axolotls offer their good repute and great symbolic power. The fact that an animal so sensitive to temperature (amphibians are regarded as the natural thermometers of the world), nutrients, and water oxygenation is able to survive among the chinampas, is indicative of the efficiency of this agricultural system. The mere presence of the axolotl guarantees the quality of what is produced there and, as a result, provides added value to the farmers.
However, to rebuild the chinampa system several obstacles must be overcome and the enemies to be defeated are not meager or meek. We are referring to development pressures—to urbanize the land, to create irregular settlements and to close off canals and irrigation ditches—that are betting mainly on the lack of agricultural vocation among newer generations. As summed up by Carlos Sumano, collaborator of the Ecological Conservation Laboratory of the National Autonomous University of Mexico (UNAM): “The chinampa agricultural system does not appeal to young people, there is no generational turnover. This is one of the principal problems, because the small farmers gradually stop working their lands and these succumb to urban development, pollution and tourism.”
This outcome is reflected in the data. Of the total protected reserve only fifteen percent is used for farming. And from this already diminished area we must further discount those chinampas where traditional agricultural practices have been altered by the construction of greenhouses and the intensive use of agrochemicals, by the search for more profitable off-season crops, by the closing off of canals and excavated areas so the land can be used for other purposes, and by the ensuing deposit of toxic residues.
Given all this, Luis Zambrano, a researcher at the Institute of Biology of the UNAM who has spent the last ten years working to save and conserve the axolotl, points out that the axolotl’s salvation is the ideal excuse for restoring the ecosystem at large. However, Zambrano is aware of the great challenge that this poses, since the issue must be approached not only from an ecological perspective but, especially, from a social one.
According to Zambrano, “The social aspect is rather complex, because it involves several economic groups—boatmen, fishermen, chinampa farmers, soccer field builders—along with local governments and tourism service providers. There are several groups with different visions, different interests and different quarrels among them. […] It is key for the success of the ecological restoration that the local community embrace and support it as their own.”
In this sense, Pedro is an example of social participation when he declares himself to be the bearer of a treasure that he is willing to defend it at all cost. When we finally reach one of the chinampas, he tells me: “Saving the axolotl means saving its environment, the water and the species that coexist with it; it means saving the chinampa, nature and trees […] It is a whole dynamic, an inclusive project, because if we do not do something to save ourselves, the axolotl will not survive either.”
In Aztec mythology, the axolotl is condemned to death. According to Fray Bernardino de Sahagun in his General History of the Things of New Spain, the god associated with duality and monstrosity fled from the sacrifice imposed upon him by other gods, who had hoped his death would give movement to the new sun. To escape, he turned himself into a two stalk maize plant (xolotl) and then a doubled maguey plant (mexolotl). Finally, he took refuge in the lake bottom as a water monster (axolotl), where he was caught and sacrificed.
The axolotl in fact began its struggle for survival a little over four centuries ago, not by escaping from the gods but from human voracity. In 1607, the construction of the so-called Nochistongo canal began. It was the first among many hydraulic works whose aim was to prevent flooding in the then capital of New Spain by diverting the lake flow out of the valley.
Since that day up to the present, Mexico Valley’s original water system has been subjected to a series of repairs and hydraulic works culminating in the existing drainage system and the disappearance of 98% of the area wetlands. The system, almost impossible to conceive, consists of pumping stations, dams, regulation ponds, collectors, canals and gigantic tunnels. Its purpose is to prevent the lake, which at its peak covered 2,000 square kilometers (772 square miles), from taking hold of the valley again.
This devastation was then followed by diverting the natural springs that fed Xochimilco to Mexico City until the mid-twentieth century when the lake’s water supply was replaced with treated wastewater injected from the megalopolis. The result? The water currently has a high salt content and a low proportion of sodium, above normal levels of fecal coliform and heavy metals such as cadmium and zinc, among others.
During the second half of the twentieth century, the Ambystoma mexicanum faced a new challenge: aggressive and disadvantageous competition from invasive species such as carp and tilapia. These fish were introduced into Lake Xochimilco in the seventies and eighties, respectively, as part of aquaculture programs then promoted by the federal government. The populations of these fish are now out of control because, as Zambrano points out, “carp are machines that devour anything and everything found near plants, including eggs and axolotl larvae. African tilapia, while they do not eat larvae, have such a large reproductive ability that they represent 95% of the canals’ animal biomass, and feed accordingly.”
Finally, there is the impact of land abandonment by local inhabitants, previously mentioned, and that of mostly domestic tourism, around two million visitors a year. The tourists, as Zambrano states, do not come to commune with nature, but to turn Xochimilco into “an authentic floating canteen.” The 48 year old biologist has complied the latest census showing the devastation to the species. This study has provided continuity to the research begun in 1998 by Dr. Virginia Graue from the Autonomous Metropolitan University (UAM), when there were 6,000 axolotls per square kilometer.
The population decline since then has been shocking. In 2004, there were 1,000 axolotls per square kilometer, and four years later barely 100. “Our latest census, conducted in 2014, shows that the population has been reduced to only 36 axolotls per square kilometer,” laments Luis, who carried out an analysis of demographic viability which is not at all encouraging. The axolotl will be extinct in the wild by 2020. “I’m not saying it, a mathematical model is, and that moment is just around the corner,” he concludes.
To reverse a process of degradation that has gone on for centuries in just a few years seems a difficult task, but it is not impossible, at least not according to the biologist. Zambrano says he is willing to do battle for at least the next five years when “he will know if his plan to save the species has worked or not.”
Several factors are on Zambrano’s side: there is the knowledge acquired over the past 10 years regarding the amphibian and its habitat, such as minimum survival requirements; his good relationship with chinampa farmers’ groups, who have contributed many of the ideas for the amphibian’s conservation; and his ability to raise awareness and involve officials.
The essence of his plan is to regenerate the environmental unit of the chinampa, through agro ecological techniques and by inhibiting the use of chemicals. Key to restoring the chinampa-axolotl synergy, the basis of the entire strategy, is to involve social actors in the process and to elevate the axolotl as a symbol of Xochimilco’s recovery. Zambrano summarizes his idea this way: “We create an easily fashioned sanctuary for the axolotls that filters water and keeps out carp and tilapia. In turn, this water, which is high quality, can be used for crops. If the axolotl, a highly sensitive species, survives in this water, then people (consumers) will be assured that the food is of high quality, organic and uncontaminated, while consumption of the same helps the axolotl survive.”
Action has already been taken. Mathematical models have been used to plot a demographic map of axolotls, and gates have been created; organic fertilizer is being produced and the water flow between the chinampas restored to create a food web. In addition, massive carp and tilapia extraction programs are underway, and a commercial network was created to provide a respectable livelihood to chinampa farmers who become involved in the program.
The next step is to increase the number of participating chinampa farmers and consequently the number of sanctuaries, to benefit the axolotl population. “How many chinampa farmers are involved? How many chinampa farmers know we exist?” Zambrano wonders. “We have worked with about 50. Of those, around seven have been contributing ideas and are implementing virtually all the measures we discussed together. How many chinampa farmers would be needed? All of them.”
This idea is encouraging to Pedro, as he calls on the chinampa farmers’ experience and knowledge, wanting them to be part of the conservation plans: “I feel that there has been a disconnect, hasn’t there? There has been a disconnect and lack of awareness about cooperation because scientists act solely as researchers. That is what they do. And we as chinampa farmers are interested in preserving our culture. Catch them and eat them, because that was the tradition.”
Alongside Zambrano’s project, there is another program to save the axolotl that has been ongoing for 20 years. The Center for Biological Research and Aquaculture Cuemanco (CIBAC) of the UAM-Xochimilco, under the tutelage of biologist Fernando Arana, is seeking to restore what was lost by reintroducing the species into certain parts of the lake system.
The biologist and his team have created an environmental management unit (UMA) that allows them to carry out the captive breeding of up to 10,000 specimens a year, “although on average we breed 5,000 a year,” says Arana. While one of his biologists shows me eggs incubated in large ponds located on the edge of a canal in Lake Xochimilco, the researcher comments that in 2013 they released 3,000 axolotls, and this year they have already released 500.” In a few months we will reintroduce 3,000 into San Gregorio Atlapulco’s conservation lake (an area of about 500 acres), the ecological reserve’s core zone. It is isolated from tourism and conditions are favorable for the axolotls’ survival in terms of pollution and predatory species.”
For Arana, conservation requires an ongoing search for potential introductions or reintroductions sites of the amphibian, “using the sites as sanctuaries, free from predators.” At the same time, distribution of harvested axolotls to responsible persons within the so-called PIMVS (lands and facilities for wildlife management) continues. PIMVS personnel receives training from Arana’s team so that “they may be able to handle, feed and breed these organisms, and even benefit from them.”
Although they share the same goal, Luis Zambrano takes issue with some of these conservation strategies: “Reintroduction programs should be carried out only when you are absolutely certain that the species is extinct.” For this UNAM biologist, the problem is that they are being introduced where appropriate conditions for survival do not exist, where “they were already eradicated.” In addition, reintroductions dramatically alter the structure of existing populations by making young native fish compete for food with reintroduced juveniles. In this situation, he adds, the danger of introducing thousands of axolotl siblings is that, besides being clones, they may be infected with chytrid, a disease that attacks amphibians worldwide. “In Xochimilco they have somehow managed to survive it.”
When Arana is questioned about his scientific peer’s viewpoint, the biologist notes that there is introduction control in lakes where no axolotls were ever present. Moreover, they have found eggs of organisms that are suitable for reproduction deposited and captured by traps. “This means that they have fed well and have reached reproductive size, regardless of any naturally occurring predation.” However, scientific publications and the results of this monitoring have not been widely disseminated,” the biologist told me.
Arana is calling for both teams to work together. For him, a major hurdle is navigating within political climates which determine funding for conservation projects. Obviously disappointed, he noted: “There is not much to do except continue the efforts we have been making and those being carried out by the UNAM to eradicate invasive species and improve the habitat.”
The UNAM’s La Cantera is an old stone quarry. When it fell into disuse, the government ceded the land to the UNAM, which turned it into a sui generis ecological reserve, stuck as it is amidst the urban chaos in the south of the capital. It is a verdant and humid oasis in one of the most conflictive poor neighborhoods in the area.
Access to the reserve is restricted to scientists and the university’s own soccer team, which enjoys the clean air during practice. One of the privileged scientists is Horacio Mena, a veterinarian at the Laboratory of Ecological Restoration of the UNAM, responsible for the axolotl colony. His efforts focus on assessing the viability of amphibian adaptation to new environments in order to create a genetic reserve. This is what Luis Zambrano has called a lifeline plan, because, as he asserts, “If extinction wins out by 2020, at least they will have an environmentally adapted colony that, yes, could be reintroduced to Xochimilco.”
Building this sort of Ambystoma mexicanum Noah’s ark involves a learning curve for Mena with the axolotl larva. He and his team have not only made partial introductions in captivity, measuring all the amphibians’ parameters, but will soon carry out an exercise in telemetric monitoring with transmitters. This will provide information about their nocturnal habits, what they feed on in the reserve lakes and the most favorable sites for their conservation. With this, the veterinarian believes there will be a 70 percent chance of successful adaptation to the environment and, consequently, a genetic reserve of the species in the wild.
However, Zambrano himself hopes they will not have to resort to plan B. If steps are implemented as planned, results could be seen over upcoming years. Trust in the great reproductive ability of the axolotl; every female is capable of laying 1500 eggs per season. “We just need to leave them alone” for the population to recover.
“What is my outlook? If we can double the amount of chinampa farmers over the next two years, my outlook is going to be much more optimistic than it is now. My view is that by 2020, or 2025 at the latest, the axolotl could be extinct within Xochimilco. But if we counteract this through the chinampa farmer’s involvement, and if we double or triple the amount of sanctuaries, even multiply the number by ten, then 2020 will be nothing more than a potential threat that we will face without a problem,” concluded the researcher.
The sun sits high. I spend the entire morning conversing with Pedroin Xochimilco. He shows me how each crop is worked, invoking time and again the knowledge that was passed down from the “elders” as key to saving the area. “I think we have to remove the blinders, chinampa farmers along with academics, and realize that we are practically on the same playing field, right? Because while it is true that they have much book knowledge, much research knowledge [...] it is also true that we have the cultural side, [...] the experience side, because we have lived with the axolotl all our lives “, he points out.
The “elders” warned him that he would be left all alone. They were referring to the fact, he says, that he was the only young man who showed an interest in continuing to work the chinampa. Regardless, Pedro says he is ready to hang tough. He talks about creating a school for chinampa farmers in the near future and attracting younger generations to the chinampa.
“Are you aware that just as the axolotls are in danger of disappearing, you might be an endangered farmer yourself?” I ask him.
“Yes. We see the lack of interest in the chinampa, it is serious and it concerns us, because if this is lost, we will have lost an entire culture, a very old culture. But we will continue to fight, providing an example, transmitting knowledge. [...] So, my task in life is to get others involved. I will settle for one more who will follow, and this will have a different future.”