In a process called photosynthesis, plants use sunlight to transform water into hydrogen and carbon dioxide, its food, and oxygen that is released into the air. But photosynthesis doesn’t just happen on land—it happens in the ocean, too.
“Phytoplankton are tiny, single-celled algae basically, that live in the ocean,” Liz Harvey, assistant professor of marine science at University of Georgia’s Skidaway Institute of Oceanography, told Georgia Public Broadcasting. “They conduct photosynthesis just like land plants, trees and grass do, and they are prolific. They grow everywhere in the ocean.”
In fact, their role is just as important as land plants, according to Harvey.
“Phytoplankton are important as they produce about 50 percent of the oxygen that you breathe. Land plants produce about half, and then phytoplankton produce about half. These tiny little microscopic organisms are actually very, very important for helping to sustain life on Earth,” she said.
Despite the significant role they play in providing oxygen, that’s not their only job.
“Phytoplankton are eaten quite regularly and serve as food for other small organisms, which are then eaten by larger organisms, which eventually lead up to fish, whales and sharks and all the really cool things that we think about when we think about the ocean,” she said.