Black smokers are hydrothermal vent structures that discharge hot, dark fluids from the ocean floor. They generally form near areas with submarine volcanic activity, such as mid-ocean ridges, where hydrothermal fluids circulate through the oceanic crust and exchange elements with the surrounding rocks. As these hot fluids come into contact with the much colder seawater, the dissolved minerals precipitate into particles and may form spectacular chimney-like structures.
The waters surrounding hydrothermal vents are often very hot and acidic, but nevertheless life is able to thrive under these extreme environmental conditions. Select groups of bacteria, known as extremophiles, can survive in these hostile environments and are capable of harnessing the hydrogen sulfide (H2S) emitted by black smokers as an energy source through chemosynthesis. These bacteria subsequently attract and are eaten by higher organisms, such as crustaceans, worms, molluscs and fish. As a result, hydrothermal vents may form the basis of entire ecosystems that are independent of solar energy. The biodiversity of ecosystems near black smokers is even thought to be higher than in the rest of the deep ocean.
For more information on black smokers and how they form, check out this article on SeaRocksBlog.org.
Information source: National Oceanic and Atmospheric Administration (NOAA).
Image: Black smokers and tube worm communities at Sully Vent in the Main Endeavour Vent Field in the northeast Pacific Ocean. Credit: NOAA.