Hydrothermal Vents

In this data package you can learn about hydrothermal vents using videos and environmental data. Some background information on hydrothermal vents can be found below and in the package itself.

Hydrothermal vents form along ocean spreading centres and back-arc basins where seawater percolates through the thin ocean crust to form hydrothermal fluid. Seawater becomes enriched in sulfur and dissolved minerals (e.g. iron, zinc and copper) through reactions with superheated rock within fractures and permeable zones in the seafloor, near the magma chamber, and is released as superheated (250° - 400° C) buoyant plumes of hydrothermal fluid. Once the vent effluent mixes with the cold seawater, minerals precipitate and form black metal sulfide deposits and tall chimneys. When the seawater does not penetrate deep enough into the ocean crust, chemical reactions are partial and the fluid is released as diffuse flow characterized by lower temperatures (20° - 50° C). The mixing of hydrothermal fluid with seawater generates steep heat and chemical gradients, sometimes at the scale of a few centimetres.

Vents are home to an endemic faunal community independent of energy from sunlight and photosynthetic organisms. The vent food web fully relies on chemical fluxes as a source of energy. Vent organisms including limpets and snails graze upon dense mats of sulphur oxidizing bacteria, whereas suspension feeders (polychaetes and bivalves) feed on the sulphur bacteria suspended in the water column. A common method for vent dwelling organisms to obtain nutrients is through symbiosis with sulphur oxidizing bacteria (Lalli and Parsons, 2010).


Lalli, C. M., and Parsons, T. R. (2010). Biological Oceanography: An Introduction. (2nd ed.). Burlington, MA: Elsevier Ltd.

Hydrothermal Vent

Grade Level

  • Undergraduate

Resource Category


Kara Aschenbrenner

Last Updated

Aug 9, 2016

Created Date

Aug 15, 2013