Consequently, the impact trickles up the food chain to other organisms dependent on fish such as seabirds and marine mammals.
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.