Why does upwelling attracts huge numbers of fish?

Introduction: The Phenomenon of Upwelling

Upwelling is a natural phenomenon that occurs in the ocean and is characterized by the upward movement of cold, nutrient-rich water from the deep ocean to the surface. This process is driven by the movement of ocean currents, winds, and the rotation of the earth. Upwelling is a vital process that supports the growth of marine ecosystems, particularly in areas where the water is otherwise nutrient-poor.

The Mechanics of Upwelling

The mechanics of upwelling are complex, but the basic principle is that wind-driven surface currents push warm surface water away from shore, which is then replaced by cold, nutrient-rich water from below. This process is known as "Ekman transport," named after the Swedish physicist Vagn Walfrid Ekman who first described it. The movement of water caused by Ekman transport can be vertical as well as horizontal, and it creates a spiral-like pattern known as an "Ekman spiral." As the cold water rises towards the surface, it brings nutrients such as nitrogen, phosphorus, and iron with it, which supports the growth of phytoplankton, the base of the ocean food chain.