Half of the oxygen we breathe comes from Phytoplankton

When we think about Earth’s sources of oxygen, we usually think of vast forests such as the Amazon, but about half of the oxygen we breathe comes from elsewhere; it’s produced by phytoplankton. Phytoplankton are tiny, single-celled plants that live in the ocean, and they serve as the base of the oceanic food chain. Yet as important as phytoplankton are to life on Earth, their interaction with our planet has only recently been studied on a global scale.