What is the photic zone?

1 Answer

The photic zone is the part of a body of water (pond, lake, ocean, etc.) where photosynthesis is possible.


Many substances in water absorb, scatter, or reflect light. Therefore, light does not often reach the bottom of a body of water. Plants and algae near the surface of the water (within the photic zone) can use penetrating light energy to synthesize sugar molecules, a process called photosynthesis. Below the photic zone and above the seafloor is the profundal zone, where the light energy is not abundant enough for photosynthesis.

The photic zone may contain abundant life. Protosynthetic organisms are food for herbivores like zooplankton and some fish. Carnivores then feed on the herbivores. Scavengers dwell in the profundal zone, where they feed on sinking dead organic matter.