Why is the sunlight zone warmer then the others?

The sunlight zone, or epipelagic zone, is warmer than other ocean zones because it receives direct sunlight, which heats the water's surface. This zone extends from the surface down to about 200 meters, where light penetration is sufficient for photosynthesis. The warmth is maintained by solar radiation, while deeper zones receive less light and are insulated from the sun's heat, leading to cooler temperatures. Additionally, warm water is less dense and tends to stay at the surface, further contributing to the temperature gradient.