Question

why is the deep sea are cold and dark​

Answer 1

Answer:

Because the light ray can enter only upto 1000 metres.Hence deep sea is dark

Answer 2

Answer:

The ocean is very, very deep; light can only penetrate so far below the surface of the ocean. As the light energy travels through the water, the molecules in the water scatter and absorb it. ... In the aphotic zone; all that's left of sunlight is a dim, dark, blue-green light, too weak to allow photosynthesis to occur.

Explanation:

Water gets colder with depth because cold, salty ocean water sinks to the bottom of the ocean basins below the less dense warmer water near the surface