Final answer:
Ocean upwelling is caused by winds displacing surface water, allowing cold, nutrient-rich water from the deep to rise to the surface. These nutrients are vital for marine ecosystems and local fisheries.
Step-by-step explanation:
Ocean upwelling is the process where cold, nutrient-rich water from the deep ocean rises to the surface when prevailing winds move surface waters away from the coastline. The upward movement of this deep water brings essential nutrients to the surface, which support a rich diversity of marine life by providing food for the bottom of the oceanic food chain.
This biological pumping of nutrients is vital for ocean ecosystems, contributing to higher levels of primary production such as photosynthesis by phytoplankton. The upwelled water carries with it dissolved minerals and organic matter that were part of deceased organisms and which help sustain the wildlife. Additionally, the productivity of certain fisheries relies heavily on these upwelling zones, making them crucial to the sustenance of local human communities as well.