Where are hydrothermal vent bacteria found living without sunlight?

Chemosynthetic bacteria live around hydrothermal vents on the deep ocean floor, especially along mid-ocean ridges where seawater interacts with hot rock. These microbes use chemicals such as hydrogen sulfide to produce energy, rather than relying on sunlight. They form the base of vent ecosystems and support animals like tube worms, clams, and vent shrimp. Hydrothermal vent communities were first widely recognized in the late 20th century and changed scientists’ understanding of how life can survive in extreme environments. They are often studied as analogs for possible life in other worlds.