Hydrothermal vents - black smokers, white smokers and warm water vents - are areas on the sea floor where water heated by volcanic activity under the seabed gushes out. Unusually, the animal communities down here don't use the sun to get their energy. Instead, chemicals in the hot waters form the basis of the food chain. Hydrothermal vent communities do, however, still rely on oxygen produced by photosynthesis in the sunlit zones.
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