Which ecosystem collapse mechanism occurs in coastal South America during a strong El Niño event?

💡 Explanation

During a strong El Niño, thermocline suppression occurs because warm surface waters prevent upwelling of nutrient-rich deep water, thus reducing primary productivity. Therefore nutrient depletion causes ecosystem collapse, rather than coral bleaching (typically in tropical regions), species displacement (generally longer-term), or oxygen depletion (related to eutrophication).

• Which risk significantly increases when coastal upwelling stalls?
• Which outcome occurs when glaciers retreat in semi-arid regions?
• Which consequence results when rapid groundwater withdrawal accelerates?
• Which outcome occurs when tectonic uplift limits fluvial downcutting alluvial valleys?
• Which outcome develops on exposed bedrock when deflation is concentrated by topographic constrictions?
• Which process dominates within a high-altitude cirque basin experiencing repeated freeze-thaw cycles?