A
cold seep (sometimes called a
cold vent) is an area of the
ocean floor where
hydrogen sulfide,
methane and other
hydrocarbon-rich fluid seepage occurs, often in the form of a
brine pool. "Cold" does not mean that the temperature of the seepage is lower than that of the surrounding sea water. On the contrary, its temperature is often slightly higher. Cold seeps constitute a
biome supporting several
endemic species.