Communities Based on Chemosynthesis in the Ocean

As everyone knows, plants use photosynthesis to convert light, water and nutrients into usable food. However, photosynthesis is not the only way that organisms have found to create the materials they need to survive. Chemosynthesis uses chemical processes that occur naturally to convert materials in to food they can use. Chemosynthesis occurs around the hydrothermal vents at deep levels of the ocean. Communities of creatures have adapted to survive in these inhospitable conditions and continue to thrive through the process of chemosynthesis.

The Hydrothermal Vents

A hydrothermal vent is like a geyser on the ocean’s floor. It spews out mineral-rich water that is heated by the magma of the Earth’s core. As the water and steam heat up, they push through cracks in the Earth’s crust and spill out into the ocean depths. These vent sites support a variety of living communities that survive in different ways.  Chemicals such as iron, sulfides, barium, calcium and silicon are found in the expelled water of the vents.


Chemosynthesis uses the naturally-occurring chemical interactions to produce compounds that marine creatures can utilize for food. Carbon-containing molecules such as microbes convert inorganic materials found at they hydrothermal vent sites into usable materials for marine life. These vents also contain microbes that can live on the inorganic matter produced at the vents. Giant tubeworms, for instance, use the bacteria in their bodies to react hydrogen sulfide with oxygen as a source of energy. The interdependence of the chemosynthesizing organisms and those that use other means to survive is complex and symbiotic. The communities form as long as the hydrothermal vents produce the temperatures and pressures necessary to cause the chemical reactions

Creatures That Survive Through Chemosynthesis

More than 300 species live around the hydrothermic vents, in spite of the harsh conditions that occur around them. Tubeworms, crabs, shrimp, clams, fish, anemones and a number of types of bacteria inhabit the waters in and near the vents. They have adapted to withstand the enormous pressures of the vents, the extreme temperatures and complete darkness that make it such a unique environment.

How A Community Develops

The process of forming a community at hydrothermal vents begins, like most life forms, with bacteria. These bacteria, called autotrophs, can oxidize the hydrogen sulfide that occurs at the vent to make energy to grow themselves. The bacteria grow so thickly that they layer begins to attract other forms of life that can feed on the bacteria. Tiny creatures such as amphipods and copepods arrive, and they attract larger organisms that feed on them. Soon, snails, shrimp, tubeworms and acorn worms arrive to scavenge and prey on the other life forms. Before long, a complex community of interdependent life is formed. These creatures can exist nowhere else but at the vents and do not exist anywhere else on the earth.  The conditions at the vents can be unstable, however. Some vents may lasts for decades, while others may last only a few years.

The recent discovery of thermal vents and the life forms they support give scientists a new opportunity to understand the organisms that inhabit the planet and how they can be used to improve human life.