The impacts of an El Nino are seen all over the world. One
that’s perhaps most easily visible from space is the change
in ocean color. That indicates a change in populations of
microscopic marine plants called phytoplankton.Phytoplankton are
tiny organisms that make up the base of the marine food web.
During an el Niño, warm waters from the western pacific migrate
eastward toward south America. Blocking the supply of nutrients
from the lower depths of the ocean to the sea surface. This
causes significant losses in phytoplankton populations,
particularly along the equator towards South America. This
decline echoes through many species. Small fish that feed on
phytoplankton starve. This affects everything from penguin
and iguana populations in the Galapagos, to governments
managing fisheries. This view from NASA satellites helps us to
understand the role of ocean phytoplankton in supporting life
on Earth.