How does the change in water temperature during El Niño affect cold water species?

During an El Niño event, sea surface temperatures in the ocean can rise significantly, resulting in changes to nutrient availability and overall ecosystem dynamics. Cold water species, which are typically adapted to live in cooler, nutrient-rich waters, can experience adverse effects on their habitats due to this temperature change.

Warmer water temperatures can lead to a decrease in the upwelling of cold, nutrient-rich water that supplies essential nutrients for primary producers, such as phytoplankton. This disruption can reduce the abundance of these organisms, which are the foundation of the marine food web and a critical food source for many cold water species. Consequently, their habitats may become less suitable for survival, as the specific conditions in which these species thrive are altered.

Additionally, increased temperatures can lead to changes in species distribution, causing some cold water species to migrate toward cooler areas, potentially leading to competition for resources or habitat loss. Such shifts disrupt the balance within the ecosystem, ultimately making it challenging for cold water species to maintain their populations and thrive.