The ancient Maya once believed that Mexico’s jungle sinkholes, containing crystalline waters, were the gateway to the underworld and the lair of a surly rain god who had to be appeased with human sacrifices.
Now, the “cenotes,” deep sinkholes in limestone that have pools at the bottom, are yielding scientific discoveries — including possible lifesaving cancer treatments.
Divers are dipping into the cenotes, which stud the Yucatan peninsula, to explore a vast underground river system.
Hefting air tanks, guidelines and waterproof lamps, they have so far mapped 405 miles (650 kilometers) of channels that form part of a huge subterranean river delta flowing into the Caribbean Sea, and they are only just starting.
Scientists investigating the network of caverns and galleries, formed by rainwater passing through porous limestone, have found a wealth of early archaeological relics and prehistoric animal bones.
They also have identified dozens of new aquatic species specially adapted to extreme environmental conditions that could have medical applications. (...)
More than 500 sinkholes (...)
Blind fish and mammoth bones (...)
The hundreds of tourists who dive and snorkel each day in any of a dozen cenotes and caves open to the public are also unwittingly destroying the ecosystems before they can be properly understood, Iliffe says.
Full article: Msnbc.msn.com