Cenote Diving at the Yucatan Peninsula, Mexico
And the value of preserving underwater cave systems
∘ The cenotes of the Yucatan Peninsula
∘ The cave divers’ legacy
∘ Diving in the Mayan underworld
∘ Preserving underwater cave systems
The cenotes of the Yucatan Peninsula
Mexico has diverse landscapes that make it one of the most important countries for cave exploration.
In particular, the Yucatan Peninsula (YP), a huge limestone platform in the southeast of the country, is one of the most attractive destinations for cave divers, as it is home to many of the longest underwater caves in the world.
There is great heterogeneity in the karstic terrain forms at YP that are interesting for cave divers but the sinkholes (dolines) are by far the most popular.
They are locally known as “cenotes” (plural), a Spanish word that derives from the Mayan term “dzono’ot”, which can be translated as “water-filled cavity” or “water pound”.
They are common topographical forms, resulting from the collapse of the limestone bedrock that exposes groundwater.
The cave divers’ legacy
Cave diving has been an increasingly popular form of specialized tourism that has positively impacted society’s perceptions of history, culture, and environmental awareness.
The YP caves have a natural and cultural heritage that provides valuable (and non-economic measurable) recreation opportunities. Cave systems serve as a historical record dating from 100.5 million years ago (MA) to the present.
As the region is the cradle of the Maya civilization, cenotes and cave systems are locally considered as sacred places by indigenous people.
In the past, cenotes were used in rituals and human sacrifices, so it is common to find archaeological artifacts and human bones that are exceptionally well preserved due to the psychochemical conditions of submerged cave systems.
Cave divers have played a role in finding and describing these artifacts, which in turn opens up the possibility for anthropologists to understand the ancient Mayan worldview.
Cave systems are also a geological record of the continuous sea-level changes that have occurred in the last glacial-interglacial cycles that Earth has experienced since the upper Cretaceous (100.5 MA).
During interglacial periods, cave systems remained covered by a shallow sea and marine reef fossils such as sponges, mollusks, crustaceans, and corals can be find inside of them.
On the other hand, during the glacial periods, which occurred mainly throughout the Cenozoic, cave systems remained dry and were frequently used as a shelter by now-extinct fauna.
There have been found well-preserved Pleistocene vertebrate fossils including ground sloths, elephant-like animals (family Gomphotheriidae), tapirs, saber-toothed predators, and even the famous skeleton of Naia, the most complete early human in the Americas.
Recently, the Sac Actun cave system, the current largest underwater cave system in the world (368 km), was listed as one of the 100 most important geological sites of the world according to the International Union of Geological Sciences (IUGS).
This could only be possible due to the efforts of many specialized cave divers who continually explored and mapped all of these underground systems.
Diving into the Mayan underworld
Adventure, history, culture, science and nature intertwine inside these caves.
Cave divers’ motivations depend on their personal goals. It may be simply out of a thirst for adventure, but also because they want to investigate some of the aspects mentioned above.
Anyway, scuba diving is a tool that allow you to see the world with a different perspective. I think that submerged caves change you.
The submerged passages are dark and silent places that can be really dangerous. You could get lost, your oxygen could run out, your equipment could be damaged or you could accidentally hit your head on a rock if you are not careful.
There are many mysteries about the underground passages. The ancient Maya used to believe that cave systems were the entrance to the underworld known as the “Xibalba”.
If you think about it, you are a visitor who descends on an equal footing with the dead people of the Xibalba.
Cave passages maintain the sacred atmosphere as you literally dive among the dead (because remember that you can find human remains).
Since you are underwater it is not easy to speak. You lose your voice during the entire dive and all you can do is enjoy the scenery.
Daily problems are left on the surface.
All these factors make diving in these places solemn and somewhat surreal…
Preserving underwater cave systems
While many cave divers did not originally learn how to dive in the area, in most cases, they quickly understand the importance of the YP cave systems once they explore them.
Nowadays, cenotes have a key ecological role in supporting unique endemic fauna adapted to the cave environments and providing the only source of fresh water to society and regional ecosystems.
There are many threats to YP cave systems, but water pollution is the most representative since there is no sewage system in the region. In most cases, people dump domestic wastewater into the cenotes without previous treatment.
Wastewater and garbage that flow through the underwater passages are potential risks to human health and wildlife. They eventually flow to the ocean and also can affect marine life.
Deforestation can also affect the cave environment as there is a change in the transport of energy and materials from the surface to the underground systems. Speaking of this, there is currently a lot of concern about the new Mexican mega-project “The Maya Train” which is expected to negatively affect the ecological dynamics of the region in the coming years.
Many cave systems are currently being destroyed to build this mega project.
Another ecological problem is the misuse of cave mapping. Landowners often use dynamite and heavy machinery to destroy cave systems to create new artificial cenotes that they can use for tourism.
Because maps can be a double-edged sword for cave conservation and there is currently no legal regulation of these practices, cave divers are often very cautious about sharing their information.
Last but not least, people can disturb the environment if they don’t know how to dive properly or don’t respect caves by littering, destroying the rock, stealing or touching archaeological or fossil artifacts, or kicking up the sediment.
Cave divers can negatively affect subterranean species as well. They can facilitate the entry of fish species that take advantage of the lights to eat endemic crustacean species that occur in dark cave passages.
These species are endangered and can easily become extinct if their environment is changed or they are directly removed from their habitat.
Cave diving allow us to see a different vision of the world, a beautiful and unknown world that is literally under our feet, but that we can lose if we don’t protect it.
This article would not be possible without Kay Vilchis (facebook and instagram), and Olinka Cortés (facebook), who kindly provided many of the photographs used in this story. I strongly recommend contacting them through their hyperlinks and follow their social media if you want to know more about cave diving in the Yucatan Peninsula. They are both experts.
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