Analyze the dynamics of global ocean circulation: Statement I: Upwelling regions along the western coasts of continents are driven by alongshore winds that push surface water offshore via Ekman transport. Statement II: Nutrient-rich deep water rises to replace the displaced surface water, resulting in exceptionally high biological productivity and rich marine fisheries. Which of the following is correct?

💡 Solution & Explanation

Both statements are correct and directly linked. Surface winds blowing parallel to coastlines interact with the Coriolis force to generate Ekman transport, moving surface water away from the shore. This divergence forces cold, nutrient-laden deep water to upwell into the photic zone, fueling phytoplankton blooms and sustaining major global fisheries off coasts such as Peru and California. Coastal upwelling zones account for a disproportionately large share of global marine fish catches.