<Li> Opportunistic stage: Organisms arrive which colonize the bones and surrounding sediments that have been contaminated with organic matter from the carcass and any other tissue left by the scavengers . One genus is Osedax., a tube worm . The larva is born without sex . The surrounding environment determines the sex of the larva . When a larva settles on a whale bone, it turns into a female; when a larva settles on or in a female, it turns into a dwarf male . One female Osedax can carry more than 200 of these male individuals in its oviduct . </Li> <Li> Sulfophilic stage: Further decomposition of bones and seawater sulfate reduction happen at this stage . Bacteria create a sulphide - rich environment analogous to hydrothermal vents . Polynoids, bivalves, gastropods and other sulphur - loving creatures move in . </Li> <P> Hydrothermal vents were discovered in 1977 by scientists from Scripps Institution of Oceanography . So far, the discovered hydrothermal vents are all located at the boundaries of plates: East Pacific, California, Mid-Atlantic ridge, China and Japan . </P> <P> New ocean basin material is being made in regions such as the Mid-Atlantic ridge as tectonic plates pull away from each other . The rate of spreading of plates is 1--5 cm / yr . Cold sea water circulates down through cracks between two plates and heats up as it passes through hot rock . Minerals and sulfides are dissolved into the water during the interaction with rock . Eventually, the hot solutions emanate from an active sub-seafloor rift, creating a hydrothermal vent . </P>

The base of the food webs in the deep-sea communities is