Upwelling refers to a rising of seawater, magma, or any other liquid. The upwelling off the California coast is caused by the wind blowing parallel to the coast.

the system of upwelling pushes water up near the coast for more new fish

Upwelling is caused by currents on the surface. When water moves from the bottom of the ocean towards the surface it is called upwelling. Downwelling is when more dense water sinks. This process moves nutrients back to the deep part of the ocean.

density currents and Earth's rotation

The two steps of upwelling is