Fluid sampling on successive cruises over a period of years reveal systematic variations in vent fluid chemistry related to volcanic events Von Damm et al. During the past two decades, battery operated internally recording temperature sensors were deployed for up to a year to record a nearly continuous time series of temperature fluctuations in seafloor hydrothermal vents on time scales from hours related to sub-tidal and tidal variations e. Long-term deployments of ocean bottom seismometer arrays provide detailed pictures of seismicity e. As a result of these technological advances, several seafloor hydrothermal sites have been the subjects of intense study for more than a decade.
Hyperthermophile and Thermophile Life has traditionally been seen as driven by energy from the sun, but deep-sea organisms have no access to sunlight, so they must depend on nutrients found in the dusty chemical deposits and hydrothermal fluids in which they live. Previously, benthic oceanographers assumed that vent organisms were dependent on marine snowas deep-sea organisms are.
This would leave them dependent on plant life and thus the sun. Some hydrothermal vent organisms do consume this "rain", but with only such a system, life forms would be very sparse.
Compared to the surrounding sea floor, however, hydrothermal vent zones have a density of organisms 10, totimes greater. Hydrothermal vent communities are able to sustain such vast amounts of life because vent organisms depend on chemosynthetic bacteria for food.
The water from the hydrothermal vent is rich in dissolved minerals and supports a large population of chemoautotrophic bacteria.
These bacteria use sulfur compounds, particularly hydrogen sulfidea chemical highly toxic to most known organisms, to produce organic material through the process of chemosynthesis. The ecosystem so formed is reliant upon the continued existence of the hydrothermal vent field as the primary source of energy, which differs from most surface life on Earth, which is based on solar energy.
However, although it is often said that these communities exist independently of the sun, some of the organisms are actually dependent upon oxygen produced by photosynthetic organisms, while others are anaerobic.
Giant tube worms Riftia pachyptila cluster around vents in the Galapagos Rift The chemosynthetic bacteria grow into a thick mat which attracts other organisms, such as amphipods and copepodswhich graze upon the bacteria directly.
Larger organisms, such as snailsshrimpcrabstube wormsfish especially eelpoutcutthroat eelophidiiforms and Symphurus thermophilusand octopuses notably Vulcanoctopus hydrothermalisform a food chain of predator and prey relationships above the primary consumers.
The main families of organisms found around seafloor vents are annelidspogonophoransgastropodsand crustaceanswith large bivalvesvestimentiferan worms, and "eyeless" shrimp making up the bulk of nonmicrobial organisms.
They have no mouth or digestive tract, and like parasitic worms, absorb nutrients produced by the bacteria in their tissues. About billion bacteria are found per ounce of tubeworm tissue. Tubeworms have red plumes which contain hemoglobin.
Hemoglobin combines with hydrogen sulfide and transfers it to the bacteria living inside the worm. In return, the bacteria nourish the worm with carbon compounds. Two of the species that inhabit a hydrothermal vent are Tevnia jerichonana, and Riftia pachyptila.
One discovered community, dubbed " Eel City ", consists predominantly of the eel Dysommina rugosa. Though eels are not uncommon, invertebrates typically dominate hydrothermal vents.
Eel City is located near Nafanua volcanic coneAmerican Samoa. It has been proposed that before the North American plate overrode the mid-ocean ridgethere was a single biogeographic vent region found in the eastern Pacific.
The examples of convergent evolution seen between distinct hydrothermal vents is seen as major support for the theory of natural selection and of evolution as a whole. Although life is very sparse at these depths, black smokers are the centers of entire ecosystems.
More complex life forms, such as clams and tubewormsfeed on these organisms. The organisms at the base of the food chain also deposit minerals into the base of the black smoker, therefore completing the life cycle. No sunlight penetrates that far into the waters. Instead, the bacteria, part of the Chlorobiaceae family, use the faint glow from the black smoker for photosynthesis.
This is the first organism discovered in nature to exclusively use a light other than sunlight for photosynthesis. The latter uses iron sulfides pyrite and greigite for the structure of its dermal sclerites hardened body partsinstead of calcium carbonate. This armor plating probably serves as a defense against the venomous radula teeth of predatory snails in that community.
Biological theories[ edit ] Although the discovery of hydrothermal vents is a relatively recent event in the history of science, the importance of this discovery has given rise to, and supported, new biological and bio-atmospheric theories.
The Deep Hot Biosphere[ edit ] At the beginning of his paper The Deep Hot Biosphere, Thomas Gold referred to ocean vents in support of his theory that the lower levels of the earth are rich in living biological material that finds its way to the surface.
Therefore, thermal energy flux is a permanent agent and contributed to the evolution of the planet, including prebiotic chemistry.Where plates are pulled away (diverge) from each other molten magma flows upward between the plates forming mid-ocean ridges, underwater volcanoes, hydrothermal vents, and new ocean floor crust.
The Mid-Atlantic Ridge, is an example of this type of plate boundary.
Deep-sea hydrothermal vents are mainly associated with seafloor spreading at mid-ocean ridges and in basins near volcanic island arcs. They host animals found nowhere else that derive their energy not from the sun but from bacterial oxidation of chemicals in the vent fluids, particularly hydrogen sulphide.
Aug 25, · Bill Nye discusses the discovery of hydrothermal vents on the ocean's floor. Hydrothermal vents generate deep-sea currents. By Tim Wogan 12 April No comments. Minerals spewed by ocean vents set up redox reactions that allow electrical currents to flow. Hydrothermal vents continuously belch out hot, mineral-enriched water, and are known to support communities of organisms on the ocean floor.
Under the sea, hydrothermal vents can form features called black smokers and white smokers. The colour depends on the minerals present in the water. On land these cracks form land hot springs, fumaroles (holes in a volcanic area from which hot smoke and gases escape) and geysers.
The Ecosystems that Thrive in Hydrothermal Vents The Ecosystems that Thrive in Hydrothermal Vents Some 7, feet below the ocean’s surface lies a intriguing and bizarre world unlike any other.
Large black volcanoes tower above the ocean floor spouting out poisonous black gas into freezing.