The euphotic zone is the upper layer of a body of water where sunlight penetrates, allowing photosynthesis to occur. This zone typically extends to a depth of about 200 meters in clear ocean waters, but it can be shallower in murky or coastal areas. The presence of light supports the growth of phytoplankton, which are essential for the aquatic food web. In the euphotic zone, various marine organisms thrive, including fish, zooplankton, and coral reefs. The productivity of this zone is crucial for sustaining life in the ocean, as it provides energy and nutrients that support a diverse range of species, including larger animals like whales and sea turtles.