We once thought that sunlight was also needed to sustain life as well. We now know that there are other communities of organisms that use chemical energy as the basis for their food web. The bacteria that perform this function are called chemotrophs and are the primary producers of these ecosystems. All the various consumers depend either directly or indirectly on these chemotrophs. Chemotroph communities are clustered very tightly around deep-sea hydrothermal vents.
Water seeps down into the ocean floor where it picks up mineral and nutrients.
Superheated by volcanic activity, this water is spewed back out into the cold ocean water. This causes metals within the hot water to change chemically and make the vent water appear as smoke.