The deeper the ocean gets, it gets colder, and the pressure is much stronger
What resources do we use from the ocean? "It provides a treasured source of recreation for humans. It is mined for minerals (salt, sand, gravel, and some manganese, copper, nickel, iron, and cobalt can be found in the deep sea) and drilled for crude oil. The ocean plays a critical role in removing carbon from the atmosphere and providing oxygen."