Coastal upwelling is a natural process in which nutrient-rich, cold water from the deep ocean rises to the surface along the coast. This process occurs when winds blowing parallel to the coastline push surface water away from the shore, allowing the cold, nutrient-rich water to rise and replace it. Coastal upwelling is important for marine ecosystems as it brings nutrients to the surface that support the growth of phytoplankton and other primary producers. This in turn provides food for fish and other marine organisms, making coastal upwelling areas some of the most productive and biodiverse ecosystems in the world. Research on coastal upwelling focuses on understanding the factors that influence the intensity and frequency of upwelling events, as well as the impacts of upwelling on marine ecosystems and climate. Scientists also study how changes in climate and ocean conditions, such as El Niño events, can affect coastal upwelling and its ecological consequences.