The photic zone (also known as the euphotic zone) is the name for the depth of water, be it in lake, sea or ocean, which is exposed to sufficient sunlight to allow photosynthesis to take place. It extends from the Atmosphere-ocean interface downward to a depth where the light intensity is 1% of that at the surface. Its exact depth is dependent, therefore, on the extent of the light reduction within that water column, or in other words, it depends on how transparent the water is. The depth of the Photic zome typically ranges from only a few centimetres, normally in muddy, nutrient rich lakes, to around 200 meters, normally a depth found in the open ocean.