Riviera Maya: Geology and Pollution is the second in our series “Can Mass Tourism be Sustainable? A series that examines the impact of rapid and uncontrolled growth on the environment and social stability of Mexico’s Riviera Maya.

playa-del-carmen-beach-mexico-rob-moses-riviera maya, mexico,, Riviera Maya: Geology and Pollution yucatan


Turbo-Charged Growth!

Since the 1980’s the Caribbean coast of the Yucatan has experienced turbo-charged mostly chaotic growth. This area saw the arrival of 4.7 million visitors in 2016 alone. Cancun is now Mexico’s second busiest airport. In 2006, Playa del Carmen was one of the world’s fastest growing cities. Today there are approximately 50,000 hotel rooms along the coast. The government plans to double that number in the near future. With sewage, waste management infrastructure, and recycling seriously failing to keep up with demand, local municipalities constantly scramble to handle the industry. (photo – Rob Moses)

These issues are not unique to the Riviera Maya; in fact they are similar to the issues facing mass tourism developments around the globe.


A Unique Geology!

To truly understand the environmental impact of mass tourism on the Yucatan Peninsula, we need to also understand the unique geology of this area. The beautiful beaches fringing the Riviera Maya are a product of the coral reefs that skirt the shoreline from north of Cancun to the Bay Islands of Honduras. It is in the interior of the peninsula, however, where our story really begins.

cenote_by_jo-ann_wilkins, yucatan, riviera maya, mexico underground rivers, Riviera Maya: Geology and Pollution

Only the western third of the peninsula has surface water. The ground is almost entirely composed of porous limestone called karst. Rain falls, but the scant surface vegetation, thin topsoil and underlying porous limestone combine to quickly absorb rainwater. Below ground, the porous limestone dissolves. This creates underground rivers, aquifers and caves. When the roofs of these structures collapse, sinkholes or “cenotes” are formed. Historically, the Mayan people built their cities in proximity to these fresh water cenotes.

The composition of this karst limestone is often compared to swiss cheese. However, whereas swiss cheese has a lot of separate holes, the spaces in karst interconnect. This allows water to percolate through the entire bedrock. Consequently, rain that fell hundreds of miles from the coast is eventually carried via underwater rivers to the sea.


Cave Diving Mecca!

The Yucatan has become world famous for cave diving where it is often more than sport. Dedicated participants have explored and mapped hundred of miles of the peninsula’s underground rivers, caves and 450+ cenotes. They have tracked how these systems interconnect with each other, the coastal lagoons and the sea. Recently they have discovered how two of these underwater river systems connect to form the world’s longest underwater river, see: Divers Discover World’s Largest Flooded Cave!


In addition to mapping, these dive teams have collected invaluable hydrologic information, including water purification and pollution contamination data. This data reveals potential threats to the area’s fresh water systems.

One of the Yucatan’s most important underground rivers is the Ox Bel Ha system. This water system empties onto the fringing reefs, just south of the Tulum Archaeological Zone (approximately 80 miles south of Cancun). Unexplored until 1998, divers have now mapped over 75 miles of the Ox Bel Ha system including 72 interconnected cenotes. If humans can swim this system, so can contaminants. Within reach of this potential contamination is the coastal tourism strip south of Tulum and the nearby Sian Ka’an Biosphere Reserve.

Tulum landfill from Dark Side of Tulum by Rachel Appel, Riviera Maya: Geology and PollutionContamination of Tulum’s fresh water supply can occur in many ways. The old, unlined landfill inland from Tulum town leeches contaminants into the porous limestone. At the same time, a newer landfill is already overfilled. The town of Tulum has an inadequate municipal waste management system; and only a small percentage of the population is connected. (photo – from Dark Side of Tulum by Rachel Appel)


Unseen and Ignored!

Since the effects of this pollution occur underground they are often unseen and ignored. But eventually this underground water reaches the sea and the beautiful beaches and coral reefs that make this area so attractive. It’s here that the effects of contamination become visible.

microalgae on coral reefs, riviera maya: geology and polllutionOlmo Torres, of Razo Natura says that the microalgae on Tulum’s reefs has nearly doubled over the last ten years. Torres believes that only one resort along Tulum’s entire coastal hotel zone has an adequate Roberto Iglesias-Prieto, a biologist from Penn State University who has been studying Mexico’s reefs for 20 years, says that contaminants from wastewater, even when treated, increases nitrogen and phosphorous levels in the sea. This produces algae on the coral reefs and “[w]hen combined with climate change…the result is disastrous.”

In doing our research for this series, we uncovered some incredible examples of poor planning, corruption and incompetent governance. But we also learned of the dedicated individuals and organizations that work to ensure that the continued development along the Riviera Maya is sustainable.
This is very much a story of contrasts. Marine reserves are established along the Yucatan coast, but illegal fishing occurs within those reserves. Recycling infrastructure is championed, yet waste is dumped without responsibility. There are attempts to preserve the area’s unique treasures, but also land grabs and greed regardless of the cost drive people to pillage.

The lessons learned through this series on the Riviera Maya hopefully provides guidance on the harmful effects of mass tourism. With these lessons in mind, other mass tourism developments worldwide can plan for a realistic and more sustainable future.

By Robert Frerck, Blue Ocean Network


See These Related Stories on Sustainable Tourism:

Can Mass Tourism be Sustainable? Riviera Maya Part 1, Beginnings
Nov. 29 – Dec. 1: Sustainable Ocean Summit
Sustainable & Responsible Tourism on Curaçao
International Year of Sustainable Tourism
Sustainable Tourism in Palau
UN Ocean Conference dives into “Life Below Water” with Sustainable Development Goal #14
Misool Eco-Resort Celebrates Ten Years of Marine Conservation
Marine Protected Areas: Good News, Bad News