Describe how light changes with depth in the ocean.

The ocean is differentiated into three zones on the basis of the light level and depth. The upper 656 feet or 200 meters of the ocean is known as the sunlight zone or euphotic zone. Only a small concentration of light passes beyond this depth. The zone in between the 200 and 1000 meters is generally considered as the twilight zone or the dysphotic zone. In this zone, the light intensity briskly disintegrates with the increase in depth. The midnight or the aphotic zone prevails in the depths below 1000 meters. The sunlight does not pass through these depths and the zone is completely covered in darkness.