Reef: Difference between revisions

A '''reef''' is a ridge or a [[shoal]] of rock, [[coral]] or similar relatively stable material, lying beneath the surface of a natural body of water.<ref name="NatGeo" /> Many reefs result from natural, [[abiotic component|abiotic]] (non-living) processes such as [[deposition (geology)|deposition]] of sand{{citation needed|reason=for reef formation by deposition of sand|date=February 2021}} or [[wave erosion]] planing down rock outcrops. However, reefs such as the [[coral reef]]s of tropical waters are formed by [[biotic component|biotic]] (living) processes, dominated by corals and [[coralline algae]]. [[Artificial reef]]s such as shipwrecks and other man-made underwater structures may occur intentionally or as the result of an accident, and are sometimes designed to increase the physical complexity of featureless sand bottoms to attract a more diverse range of organisms. Reefs are often quite near to the surface, but not all definitions require this.<ref name="NatGeo" />