The portion of the ocean
floor where sunlight
does not penetrate
, from 2000 to 6000m or 6500 to 19500ft. About 3/4 of the ocean floor
lies in this region. The temperature
is very cold, about 4C, 37F. The pressure
The region above is the bathyal zone; the region below, the hadal zone.
The abyssal zone contains no algae or phytoplankton as it is too dark for photosynthesis to take place. Almost all animals that dwell at such depths are carnivores, that feed on sediment or detritus from the above levels. Many of these animals are blind, or have their own light sources. Research at such a depth is difficult, and therefore incomplete.
Also the setting in The Abyss.