What happens in ecosystems with no sunlight?

In ecosystems devoid of sunlight, such as those found in deep-sea environments or certain underground habitats, organisms rely on chemosynthesis instead of photosynthesis. Chemosynthesis is a process by which certain organisms, often bacteria, convert inorganic compounds, like hydrogen sulfide or methane, into organic molecules using energy derived from chemical reactions rather than from sunlight. This ability allows these organisms to create their own food in the absence of light.

The significance of chemosynthesis is profound as it forms the basis of food webs in these ecosystems. For example, in hydrothermal vent communities, chemosynthetic bacteria are primary producers that support a unique ecosystem composed of various trophic levels, including specialized consumers that feed on these bacteria. This process is essential for sustaining life in environments where photosynthetic organisms cannot survive due to lack of light.