Seafloor microorganisms need to cope with higher pressures the deeper they are buried. In deep-sea sediments, these microorganisms withstand pressures hundreds of times higher than what we experience at the surface of the Earth. Therefore, scientists study these microorganisms to understand the limits of life and the strategies these microorganisms use for survival. These microorganisms inspire us to invent new materials and medicines for coping with extreme environments. They also play a part in regulating carbon and oxygen, and the Earth's climate over its long history. Some of the microorganisms produce interesting chemicals, such as methane, which we may use to generate energy.
As the microorganisms are buried, the tremendous amount of seawater and sediments above squeeze their living environment. The deeper the microorganisms are buried, the less water is in their immediate environment. Thus, while the seafloor is right under seawater, the microorganisms under the seafloor can face a lack of water.
Another challenge to these deep microorganisms is a lack of food. Less than 10% of the organic food from the sea surface eventually reaches the seafloor.

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