This resource provides an overview of normal, El Niño, and La Niña conditions in the Pacific Ocean, focusing on the impact of trade winds, thermoclines, sea surface temperatures (SST), and upwelling on marine ecosystems. It explains how trade winds push warm water west during normal conditions and weaken during El Niño, causing significant shifts in ocean currents and temperature. It also discusses La Niña's effect, characterized by stronger trade winds and cooler sea temperatures. The document highlights the interconnectedness of oceanic conditions and their implications for the ecosystem, such as the thriving of Peruvian anchovies due to nutrient availability from upwelling, and poses critical thinking questions regarding the environmental impact of these phenomena.