A chemosynthetic ecosystem is recognized as a living community with interrelationships between the organisms and the inorganic compounds used for energy acquisition. The oldest Glade of thermophilic prokaryotes possesses chemosynthetic physiology, and they have been the principal source of bio-production at deep sea hydrothermal vents since the first such ecosystem was established some 3.8 to 3.5 billion years ago. Modern communities based on primary production by chemolithotrophic prokaryotes exist in many kinds of environment, such as deep aquifers, geothermal hot springs, hydrothermal vents, cold seep areas, and the subsurface of the sea floor. Their contribution towards production within the whole marine ecosystem has been disregarded because of its very small estimated production compared to the entire photosynthetic production. However, it has become apparent that the extent of such chemolithotrophic habitats is much greater than previously realized, and it has become necessary to reconsider the role of chemosynthetic production within certain limited areas. Chemosynthetic ecosystems in the deep sea may create a specific ecotone of increased biodiversity and biomass at their boundary.
