Steps towards surviving without oxygen: The Movile caves
Movile caves an ecosystem sealed off from the rest of the world for about 5.5 million years. It is biological marvel as its host life in a place hostile to life. This cave is located in the southeast part of Romania in Constanta country, close to the black sea and the Bulgarian border, in a barren featureless land.
The movile caves were discovered in 1896, by prospecting crew in southern Romania when they are testing the ground for the geothermal powerplant site. Romanian scientist, Cristian low was the first person to descend into the unknown danger of the caves. This cave had been sealed from the rest of the world millions of years ago, by a huge limestone slab which fell on its entrance, making it a time capsule crawling with strange and unknown life. More than 20 meters underground the cave is pitch dark, warm, and full of toxic gases. It also holds a lake filled with sulfurous water that reeks of burnt rubber and rotten eggs. The thick layer of clay above the cave prevents everything from seeping down the cave from the earth’s surface.
Movile lakes' water is covered by a tissue paper-like mat made up of billion of autotrophic bacteria which can turn inorganic compound like carbon dioxide along with some energy, into foods the air in the cave has about hundred times more carbon dioxide than the outside air which provide them all the carbon dioxide they need. On the earth's surface, plants use carbon dioxide and light to make food by the process called photosynthesis. But their bacteria inside the caves cannot perform photosynthesis because they live in complete darkness and don't have access to sunlight so instead, they derive their energy from chemical reactions involving toxic gases in the cave-like hydrogen sulfide to drive their food. This process is called chemosynthesis. Other bacteria floating in the cave use methane gases as their only source to get carbon and energy. These chemosynthetic bacteria support the entire ecosystem of the cave. Reaction involving hydrogen sulfide gases produces sulphuric acid which erodes the limestone walls overtime.
This usually makes the cave bigger and release more carbon dioxide.
So far 48 species are found in the movile cave, out of which 33 species are not found in any other part of the earth. The inhabitant of the cave includes unique spiders, scorpions, woodlice, centipedes, water scorpions, etc. This organism shows troglomorphic adaptations that are associated with life in the dark. Most of the creatures have no eyes translucent skin and they have extra-large antennae. Which makes t easier for them to move about in the darkness. It has been found that the deeper one goes into the cave, the quality of the air deteriorates but the sign of life increases.
The movile cave's special ecosystem throws light on what life was in the primordial past. This cave is an extraordinary example of how life finds a way to thrive even in extreme survival conditions.