Thus both blow towards the equator. This is Ekman Transport, which, like the Coriolis Force, is a result of the Earth's rotation. Once again, the divergence in surface water allows deep water to rise to the surface. The oceans are thermally stratified, so that the water rising from depth is colder than the surface water. Another interesting and important aspect of deep ocean water is that it is rich in nutrients.
Most marine organisms live near the surface.
When they die, their bodies sink. As they sink, they are slowly decomposed by bacteria, releasing nutrients back into the deep water. Thus the deep water in the ocean is enriched in nutrients. When upwelling occurs, these nutrients are carried to the surface. The nutrients stimulate growth of the algae, or phytoplankton, living in the surface water.