Cold seep
ocean floor area where hydrogen sulfide, methane and other hydrocarbon-rich fluid seepage occurs / From Wikipedia, the free encyclopedia
A cold seep (sometimes called a cold vent) is an area of the ocean floor where hydrogen sulfide, methane and other hydrocarbon-rich liquids leak out of the Earth's crust, often in the form of a brine pool. Cold seeps form a biome supporting several native species.
Cold seeps change the shape of the ocean floor over time, where reactions between methane and seawater create carbonate rock formations and reefs. These reactions may change when bacteria are present.