1. of or relating to the upper layer of a body of water that receives enough sunlight to support photosynthesis
Usage: technical; biology; oceanography

Examples

• The euphotic zone extends from the surface to about 200 meters in clear ocean water.
• Algae and phytoplankton thrive in the euphotic layer where light penetrates.
• Marine biologists study the euphotic region to understand ocean productivity.
• Below the euphotic zone lies the twilight zone, where little light reaches.
• The depth of the euphotic zone varies depending on water clarity and season.