Important coastal upwelling areas occur along the West Coast of North America where the California Current moves southward. Along the Southwest coast of Africa the Benguela Current exhibits similar dynamics. Temperate Upwelling regions are continental margins characterized by the consistent welling up of nutrient rich bottom waters to the surface. These regions are remarkably productive and are associated with large fisheries and correspondingly large populations of seabirds. Fish populations are generally enormous, schooling, and characterized by great amounts of biomass but relatively few species of small fish (e.g., the Peruvian anchovetta).
The high productivity in Temperate Upwelling regions is based on large quantities of low diversity phytoplankton communities that support short, relatively uncomplicated food chains. Species diversity is variable and often includes species entrained from deep upwelled water. These regions are largely characterized by low precipitation, and adjacent terrestrial ecoregions are often arid.