Since their discovery in 1977 hydrothermal vent communities have
provided a wealth of surprises about life in the deep-sea and in extreme
environments. In contrast to most other marine ecosystems which largely depend
on photosynthesis, these faunal communities are characterized by their
dependence on geochemical energy sources (largely hydrogen sulfide and
methane). These faunas pose numerous questions about how and when they adapted
to these environments, and how they survive under such extreme conditions. Soon
after the discovery of deep-sea vent faunas, ecosystems with a similar suite of
taxa were found at hydrocarbon seeps in the deep-sea (cold-seeps), at sunken
whale carcasses (whale-falls), and sunken driftwood (wood-falls). Such
environments are now known as ‘chemosynthetic ecosystems’.