http://www.bbc.co.uk/nature/habitats/Hydrothermal_vent http://www.bbc.co.uk/nature/habitats/Hydrothermal_vent one of the most extreme ecosystems on Earth http://www.bbc.co.uk/nature/habitats/Hydrothermal_vent Black smoke BBC page Videos of black smokers http://www.bbc.co.uk/nature/habitats/Hydrothermal_vent