The deep-sea environment, which starts at a depth of 3,280 ft. is distinctly different from the surface environment. In the deep sea environment, there is no sunlight, water temperatures are cold, salinity is constant, and hydrostatic pressure is high.

Some 1,030 species of benthic sponges, cnidarians, barnacles, isopods, decapods, sea spiders, echinoderms, and beardworms- all quite small - live in the deep sea environment. However, the discovery of a new type of deep-sea ecosystem at the Galapagos Rift in 1977 provided a striking exception to the metabolically slow paced species that are most commonly found in this unique environment. Hot water emanating from vents along the axis of the equatorial Pacific spreading center was found to support a relatively large animal that rapidly grew to maturity and produced a large number of larvae. It is believed that this behavior is the result of hydrothermal vents.

Since then, many hydrothermal vent fields have been found inthe Atlantic, Pacific, and Indian oceans. Many of these fields include so called black smoker chimneys: tall, cone-shaped
structures spewing 350°C (660°F) black water, rich in metallic sulfides into the cold sea water. This interface of hot, metal-rich broth and cold, high-salinity sea water in a high pressure,
sunlight-free environment makes for a unique breeding ground which is home to thriving ecosystems. Life within these vents takes many shapes, including 3.2 foot long tube worms and 10 inch clams, shrimp and eels, octopus, and many other fascinating creatures. The food source upon which these communities survive is a diverse ecosystem in itself, made up of microorganisms. These microorganisms need energy to carry out their life processes, and use the energy released when an element such as sulfur or iron (available in the heated, reactive vent fluid) changes chemical oxidation states, as the source of that energy.

It is a unique world that surrounds a hydrothermal vent, and scientists are just barely beginning to understand how life came to be there. It is tenuously believed that the ‘last universal common ancestor’ of all living beings today may have lived as part of a hydrothermal vent ecosystem. Studies related to deep ocean communities have become popular in the area of
Astrobiology, specifically the areas of landing site selection on Mars and exploring Europa for a subsurface ocean. For additional information on these exciting areas of astrobiology research, check out http://astrobiology.asu.edu/