what is deep sea
The deep sea begins below about 200 m, where sunlight becomes inadequate for photosynthesis. From there to about 1,000 m, the mesopelagic or twilight zone, sunlight continues to decrease until it is gone altogether.This faint light is deep blue in color because all the other colors of light are absorbed at depth.he deep sea begins below about 200 m, where sunlight becomes inadequate for photosynthesis. From there to about 1,000 m, the mesopelagic or twilight zone, sunlight continues to decrease until it is gone altogether.