The ocean water column is made up of five zones: the sunlight zone (epipelagic), the twilight zone (mesopelagic), the midnight zone (bathypelagic), the abyssal zone (abyssopelagic) and the hadal zone (trenches).
The abyssal zone, or the abyss, is the seafloor and water column from 3,000 to 6,500 meters (9,842 to 21,325 feet) depth, where sunlight doesn’t penetrate.
The region extending from 6,000 to 11,000 meters is called the hadal, or hadalpelagic, zone after Hades, the Greek god of the underworld. They occur only in trenches across the…
The upper layer of the ocean is known as the sunlit, or euphotic, zone. Because water strongly absorbs light, sunlight penetrates only to depths of about 200 meters (656 feet).