During El Niño, upwelling of cold nutrient-rich water weakens or ceases entirely, resulting in reduced phytoplankton.
The effects of El Niño are also felt in marine populations. During El Niño, upwelling of cold nutrient-rich water weakens or ceases entirely, resulting in reduced phytoplankton. This leads to a scarcity of food for the fish populations that rely on phytoplankton as a primary food source. Consequently, the impact trickles up the food chain to other organisms dependent on fish such as seabirds and marine mammals.