Definition: The marine abyssal zone biome comprises regions of the marine benthic biome between approximately 2500 m and 6000 m depth. This zone generally coincides with the continental rise and the abyssal plain.
Definition: A slope which bridges a continental slope and an abyssal plain, is formed by the accumulation of sediments transported from a continental slope by processes including turbidity currents, and has a gradient less than a continental slope yet greater than a continental shelf.
Definition: The bathypelagic zone biome comprises the marine water column below approximately 1000 m water depth - the maximum depth to which detectable daylight penetrates in all but the clearest oligotrophic waters - and extends to about 2500 - 2700 m water depth. In the temperate Atlantic, the beginning of the bathypelagic zone biome approximates to the deep oxygen minimum and the base of the permanent thermocline.
