Explanation

Ocean upwelling is specifically defined as the rising of deep ocean waters, often triggered by prevailing winds blowing surface water offshore. This process brings nutrient-rich water to the surface, which is supported by Source 4: "Ocean upwelling is the rising of deep ocean waters that occurs when prevailing winds blow along surface waters near a coastline... As a result, the nutrients once contained in dead organisms become available for reuse by other living organisms. "