Critics call for halt to road construction in Mexico’s Sian Ka’an Biosphere Reserve

MEXICO CITY — In early October, Mexico’s environment ministry published a statement about minimizing infrastructure development inside the Sian Ka’an Biosphere Reserve, a protected area on the Caribbean coast. But environmental groups say road construction continues to move forward there, threatening mangroves, cenote sinkholes, and dunes.

The courts should address a lawsuit filed by local communities to halt the road construction and repair ecological damage, they said. They added that while the statement by the ministry, formally the Secretariat of Environment and Natural Resources (Semarnat), is hopeful, it doesn’t provide the same legal guarantees as a court ruling.

“We want certainty for the communities that, first, the project is canceled, and second, that they repair the damage already done,” Viridiana Maldonado, co-coordinator with Territorios Diversos para la Vida, an environmental NGO that supports Indigenous peoples defending the environment, told Mongabay. “Because a good part of the project is already built, the damage is done. They cut down mangroves, they cut down forest, they interrupted hydrological flows.”

The Sian Ka’an Biosphere Reserve covers more than 528,000 hectares (1.3 million acres) of mangroves, rainforests, and dunes in the southern state of Quintana Roo. It received UNESCO World Heritage status in 1987 and provides extensive habitat to jaguars (Panthera onca), Central American tapirs (Tapirus bairdii), and hundreds of migratory birds, among other species.

The reserve also has 47 community-based tourism initiatives and 140 permits for tourism and recreational activities, according to Semarnat.

The Puerta al Mar (“Door to the Sea”) project underway in the region includes 54.6 kilometers (33.9 miles) of road, of which 23.7 km (14.7 mi) lie inside the reserve, connecting the town of Felipe Carrillo Puerto to the coastal village of Vigía Chico. The project also includes a parking lot, storage area, security booth, electrical substation, and infrastructure for processing water, among other facilities.

The defense ministry (or Secretariat of National Defense, Sedena) is overseeing the project as part of the larger development of Tren Maya, a 1,554-km (966-mi) train line in the Yucatán Peninsula that also includes hotels, roads, and other infrastructure.

Other projects involving Tren Maya have come under scrutiny for alleged deforestation, displacement of Indigenous communities, and the destruction of underground waterways.

Sedena and Semarnat didn’t respond to a request for comment for this story.

In 2021, then-President Andrés Manuel López Obrador issued an order fast-tracking the issuance of permits and licenses for Tren Maya and other projects, saying the projects were “of the public interest and national security.” It was under that order that the Puerta al Mar road project broke ground in 2023 without a standard environmental impact study or consultation with local communities, among other putative prerequisites.

In April, Semarnat issued conditional approval to Sedena for its environmental impact study while also noting that more would have to be done to prevent damage to terrestrial and aquatic ecosystems.

In response, local communities filed an injunction to permanently cancel the project and restore areas that had been damaged by construction. The injunction, originally filed in June, was rejected twice due to alleged failure to establish the plaintiffs’ legal standing, among other points.

It was filed by eight Indigenous residents of Felipe Carrillo Puerto and 83 residents of the coastal town of Punta Allen, six fishing cooperatives, and one private business.

“Sian Ka’an is a territory of enormous ecological, cultural and community importance. The communities that have cared for it for generations have the right to be part of the decisions that affect their territory,” said a statement signed by more than 30 advocacy groups.

This month, during an appearance in the lower house of Mexico’s Congress, Semarnat head Alicia Bárcena stressed the importance of the reserve and issued a statement about the threat that construction poses to the environment and local communities in the reserve.

“Only the minimum necessary infrastructure will be promoted for conservation activities and to strengthen community tourism, preserving the environmental vocation of this natural heritage,” her office said in a social media post.

However, conservation groups said they still want the injunction to be addressed by the court because Semarnat’s statement isn’t a legal guarantee that road construction won’t continue.

A court ruling would make the road project cancellation permanent and create a pathway for ecological restoration, they said.

“Of course we welcome and embrace the statement [made by Semarnat],” Maldonado said. “But it has no legal backing. The secretary only said it and that’s not enough to provide legal certainty and guarantee that the project is effectively not going to be carried out.”

Banner image: The coastline in the Sian Ka’an Biosphere Reserve. Image by Paul Keller/Flickr. CC BY 2.0

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Cite this article

Maxwell Radwin (2026). Critics call for halt to road construction in Mexico’s Sian Ka’an Biosphere Reserve. Mongabay Conservation news. DOI: https://doi.org/10.66709/news-333741