Its turbid cold waters are home to the largest fish stocks in the world: the Humboldt Current system, which runs along the Peruvian and Chilean coasts, boasts exceptional biological productivity thanks to a very intense coastal upwelling phenomenon – ascents of deep nutrient-rich waters. Thanks to high-resolution models of the oceanic circulation and water oxygen content, researchers have now quantified this ecosystem's sensitivity to various disturbances in the equatorial Pacific....