A controversial train heads for the Maya rainforest

Every day at sunset, a 3-million-bat whirlwind emerges from a cave and floods the night sky of the Calakmul Biosphere Reserve. The cave—El Volcán de los Murciélagos (the Bat Volcano)—hosts at least seven bat species and is a pillar of the region’s ecosystem. Ecologist Rodrigo Medellín Legorreta of the National Autonomous University of Mexico (UNAM), University City, calls it “the most important bat colony of the neotropical region.” But he and other scientists say the bats and other native species could be in jeopardy as a new train makes its way through the Maya rainforest.

The Maya Train, named after the Indigenous people of the Yucatán Peninsula, is a controversial $9.8 billion megaproject that aims to transport more than 40,000 passengers daily across 1500 kilometers of southeastern Mexico. It’s backed by Mexican President Andrés Manuel López Obrador, whose administration says it will boost transportation in the Yucatán Peninsula and bring much-needed development and tourism. The United Nations predicts the train will create almost 1 million new jobs and double economic growth in the region. López Obrador has promised that, like other megaprojects, the train will be finished by the end of 2023.

But many scientists, along with some Maya activists, worry the train and accompanying development will have devastating, irreversible impacts, fragmenting the rainforest, reducing and polluting habitats, and disturbing ancient sites.

“Wherever the train crosses, it will affect the archaeology and rainforest,” says Romel Rubén González Díaz, a Maya activist and coordinator at the Regional Indigenous and Popular Council of Xpujil.

An executive summary of the project’s risks, released by Mexico’s National Council on Science and Technology in 2019, warned of possible damage. It said the train would threaten at least 10 protected natural areas and nearly 1300 archaeological sites, and affect more than 143,000 Indigenous people living along the proposed route, with the rise in tourism potentially worsening pervasive human and drug trafficking.

The full report has still not been published, and track is already being laid. Critics hope there’s still time to shape the train’s second phase of 900 kilometers, which is still on the drawing board, and minimize damage.

In June 2020, amid heated debate, the National Fund for Tourism Development (Fonatur) began to build the train’s first phase, which will transport locals and tourists 635 kilometers from Palenque in Chiapas state, near an ancient Maya city, to Izamal in Yucatán state, a colonial city founded over an ancient Maya settlement (see map, below). The route passes through savanna, mangroves, and rainforest that house thousands of species, many of them endangered, including jaguars, tapirs, scarlet macaws, Yucatán black howler monkeys, and many species of bats.

No stopping this train

Construction has begun on the first phase of the Maya Train, which is expected to bring a flood of tourists to the Yucatán Peninsula. Scientists worry a planned second segment will also slice across protected natural areas, fragmenting the rainforest and opening up remote archaeological sites.

Map of Maya Train plans
CREDITS: (MAP) K. FRANKLIN/SCIENCE; (DATA) Y. RAMOS, E. LILIAN CONTRERAS, P. SOTO, A. PADILLA, AND H. OSORIO/SERENDIPIA; TREN MAYA/FONATUR/SECRETARY OF TOURISM

Fonatur’s scientific advisers note that trains are more environmentally friendly than highways, and almost half the train will run along the route of existing tracks. Decisions about the train “are based on scientific evidence,” says neuroscientist Javier Velázquez Moctezuma, a Fonatur adviser.

But some researchers say the project was poorly planned and rushed. In November 2021, López Obrador issued a presidential decree categorizing the train and other megaprojects as matters of public interest and national security in a move to speed construction and overcome multiple injunctions filed to stop it. And 2 weeks ago, soil instability forced planners to shift the route of phase two. “It would’ve been wise for the planning to be ready many years before,” says Gerardo Ceballos González, a UNAM ecologist who has supervised some of the train’s environmental mitigation plans. “But we have to work with what we have.”

Scientists and Indigenous leaders including González Díaz also contend the environmental analysis to date has been incomplete and superficial. In January 2021, more than 160 academics criticized the Environmental Impact Manifestation (MIA), a report required by law and approved on 30 November 2020, 6 months after construction had begun. They posted a lengthy report claiming the MIA fails to acknowledge the impacts of ecosystem fracture, worsening air quality, noise, vibration, and pollution. The government has not responded to criticism, says Ana Esther Ceceña Martorella, an economist at UNAM’s Institute of Economic Research. “It doesn’t seem like they want to listen.”

Fonatur officials say the plans include mitigation strategies, including many underpasses or overpasses allowing animals to cross tracks or highways. But Shelley Alexander, a landscape ecologist at the University of Calgary, says that although some animals adapt well to wildlife crossings, large carnivores such as jaguars have a harder time. The wildlife crossings planned for the Maya Train are “a Band-Aid on a very sensitive habitat.” She says crossings should be specifically designed for both small and large terrestrial animals as well as arboreal ones, and integrated with fencing of the train tracks. Still, she says: “It’s important not to completely condemn the project based on the fact it might not be perfect, because that can then stop any [mitigation] from happening.”

The most important mitigation strategy, Ceballos González says, is to expand and further fund already-protected areas near the train’s route, such as the Calakmul Biosphere Reserve and Tulum National Park. Those measures could constrain future development and prevent further ecological damage.

As for the Bat Volcano, the train’s route originally paralleled a highway only 10 meters from the cave. Bat researchers said this would put low-flying bats—already being struck by cars on the highway—at risk and disturb the cave with noise and vibration. Fonatur says the train will now run behind the cave, but official maps aren’t yet clear on the exact route; scientists say the tracks should be at least 700 meters away.

Elsewhere the train runs near famous Maya archaeological sites such as Chichén Itzá and Tulum, as well as thousands of unexplored or undiscovered ruins. To document sites that may be disturbed by the train, 240 archaeologists and 1200 other workers and specialists have explored more than 800 kilometers of the route in 11 months, according to the National Institute of Anthropology and History (INAH) and Fonatur. “It has been a challenge,” says Fonatur’s lead archaeologist, Jesús Samuel Hernández Hernández. So far, they have recorded more than 19,000 Maya artifacts, including stelae, monuments, and house foundations, and more than 160 burials. This will yield “more than 600 papers and books for the next 10 to 15 years,” Hernández Hernández predicts. He argues that by identifying unknown sites, the project will decrease looting.

But Francisco Estrada Belli, an archaeologist who studies Maya culture at Tulane University, says the train will bring “inevitable losses” to archaeology. He acknowledges the salvage work but worries that because the excavations are not led by a research question, most of what is found will remain in archives and not contribute to archaeological knowledge, as has happened in other salvage work around the world.

One archaeologist working on the excavations agrees. “It’s just an immense amount of data,” she says, asking to be anonymous because she is not authorized to talk to the press. “I don’t think anyone is going to be able to really do true research.” She says managers pressure archaeologists to work faster. When a burial is found, they log data quickly and seal them by the next day with little interpretation. “It’s like a formality so that everything is checked off and the train construction can start.”

Hernández Hernández and others insist the digs aren’t rushed. “During salvage excavations there are always time pressures,” says INAH archaeologist Manuel Eduardo Pérez Rivas, who leads the salvage project. “But we have the technical and academic elements to do things efficiently and carefully.”

At the moment, data on artifacts and locations are kept confidential to avoid looting, Pérez Rivas says. But after sites are registered and protected, he says, the data will be accessible to the scientific community.

Archaeologists also worry about the new development the train will bring. The thousands of tourists who already visit archaeological sites in the Yucatán Peninsula have a detrimental impact on the ruins, Estrada Belli says. Their numbers are expected to skyrocket. The Maya Train is projected to attract about 3 million visitors each year to the ancient city of Calakmul, for example, compared with 40,000 each year today. It may also spur local population growth, Medellín Legorreta says. “[This] terrifies me.” The Yucatán Peninsula, now home to some 5.1 million people, “cannot sustain an increase in population.”

Pérez Rivas says INAH and Fonatur are working together to create a strategy to manage tourism responsibly and protect the region’s heritage, species, and ecosystems.

Ceballos González is hopeful the train can be built with little damage. “We have to take advantage of the opportunity the train brings to try and mitigate some of the impacts already happening,” such as illegal logging and hunting, and intensive farming, he says.

But many remain skeptical, including Medellín Legorreta. “Academia and the world are waiting to see what will happen with the Maya Train.”

source: sciencemag.org