Vent Biology: Photosynthesis vs. Chemosynthesis
All living things need energy. People and other animals get their energy from the food they eat. However, neither the plants on land nor the microbes that live around hydrothermal vents eat. Instead, they manufacture their own food.
Plants harness energy from the sun to manufacture sugars. This process is called photosynthesis. Sunlight, however, does not reach the hydrothermal vent communities at the bottom of the ocean. Instead, the microbes get their energy from different chemicals in hydrothermal fluid. For example, some get their energy by breaking down hydrogen sulfide.