The Yucatan Peninsular houses perhaps the most impressive and spectacular karst aquifer system on our planet, covering an approximate area 165,000 km2 stretching through Mexico, Belize and Guatemala. The aquifer system is a river layered by the differing densities of warm saline water absorbed from the ocean beneath the limestone and the cooler fresh water seeping down from above, with the halocline being the interface between these two layers and the mixing zone where the two waters meet, creating a third water type. There are continuous studies and research programmes being performed throughout the Yucatan Peninsular helping scientists to develop a better understanding of the water of our planet.
The state of Quintana Roo itself is presently home to thousands of cenotes and 394 cave systems with a total of 965 miles of underwater cave passage. Over millions of years the bones and skeletons of fish, crustaceans and other sea life built up the 2.5km/1.6m thick karst plateau of the Yucatan Peninsular. The rise and fell of ocean levels due to glacial periods throughout our planet's history resulted in the plateau becoming, according to geologists, one of the youngest formed pieces of the Earth. During the periods of low sea level, rainwater seeped through the extremely porous limestone, percolating into the ground and dissolving the weaker limestone beneath, thus forming passages and caves. Dissolved limestone (calcium carbonate), dripped into the passages and caves over thousands of years, solidifying and sculpting into the beautiful and intricate displays of speleothems that we are lucky enough to explore today.
Inhabiting the cave environment are a large collection of troglobitic vertebrates, crustaceans, microscopic organisms and bacterial colonies some of which are completely unique to the underground caves of the Yucatan Peninsular. For the most part these inhabitants of the dark are completely devoid of pigmentation and use sensory organs rather than sight to navigate the extensive passageways in the search for food. Continuous learning and research about these life forms is essential to understanding the underwater environment, with the evolution of bacterial colonies being of specific interest to scientists and microbiologists.