The ocean and microscopic marine plants called phytoplankton are what produces the most oxygen on Earth.
Microscopic marine plants known as phytoplankton contribute to roughly half of the planet Earth's oxygen production through a process called photosynthesis.
This is significantly more than what the terrestrial plants like trees produce in oxygen.
Phytoplankton are tiny, drifting algae that are the primary oxygen producers in the ocean and are responsible for a large portion of the oxygen on Earth.
The majority of Earth's surface is covered by oceans so marine life generate more oxygen than land plants.
And like all other plants, phytoplankton use sunlight, water and carbon dioxide to create the oxygen as a byproduct of photosynthesis.
The oxygen on Earth is produced by photosynthesizing organisms that live in the ocean, in fresh water, and on land.
These organisms that produce oxygen include bacteria, algae and plants.
Photosynthesizing algae in the ocean produce around 70% of oxygen in the atmosphere.