Does the box jellyfish live in the benthic or pelagic environment?

Phytoplankton live near the surface of the ocean because they need sunlight like all green plants. They also need water and nutrients to live. Phytoplankton use water and CO2 to grow, but phytoplankton still need other vitamins and minerals, like iron to survive.

When the surface of the ocean is cold, the deeper parts of the ocean bring these nutrients to the surface and the plankton live. But, when the surface of the ocean is warm, as in El Niño, the ocean does not bring as many of these essential nutrients and the phytoplankton die. That causes a major problem because phytoplankton are at the base of the food chain. So, when the population of phytoplankton is reduced almost the entire food chain is effected.