This is a question about water column zones in oceanography?

Question

Describe the differences in pressure, temperature, and light in the different layers of the ocean. where is the darkest? Where is the coldest? Where is the presssure the greatest?

Answer 1

In general

The deeper you go the darker it gets.

The deeper you go the colder it gets.  Warm water rises cold water falls.

The deeper you go the more pressure there is.

The saltier the water the heavier it is, so that will flow down.

You may get layers of warmer saltier water flowing down.  Sometimes you may get layers in the water of different heat and density.  This is kind of like an inversion layer in the air may trap smoke close to the ground.