The vastness and virtually unbounded domain of the ocean has inspired curiosity, fantasy, superstitions as well as fear. Through the growing understanding of the sea by humans, scientists have been able to make large advances in science and technology. In 1977 a three-person submersible alvin tank sank through the cold and inky darkness of the Pacific to find, nearly 8000 feet on the ocean floor, an underwater mountain range with newly formed hydrothermal vents. What they found was a whole new ecosystem. Down in this deep underworld, scientist found species where they thought no living thing could survive. The conditions are a harsh combination of toxic chemicals, high temperatures, high pressures, and total darkness. These animals have adapted to these conditions by a variety of ways, including body shape, bioluminescence, vertical migration and slow metabolism.
Hydrothermal vents are underwater oases, providing habitat for many creatures that are not found anywhere else in the world. More then 300 species have been identified since the first vent was discovered. Deep sea hydrothermal vents form along mid-ocean ridges, the volcanic undersea mountain ranges where new seafloor is created. What happens is cold seawater seeps down through the cracks of the ocean floor and is heated by molten rock deep below the ocean crust. The hot fluid then rises and gushes out of the vent openings. This hydrothermal fluid carries with it dissolved metals and other chemicals from deep below the ocean floor. Then an amazing group of organisms have evolved around these vents. They range from tiny bacteria that feed off the chemicals to large tubeworms that feed off the bacteria. .
Bacteria play a large role in the food chain of deep-sea world. Bacteria convert chemicals that come from the vents into energy through chemosynthesis. Other animals then eat the bacteria, harbor it in their bodies, or eat bacteria eaters.