Humans, animals, and plants all need Oxygen ot survive. Oxygen, or O2 is an odorless and tasteless gas that is needed for the function of living things. Oxygen is actually the most abundant element on Earth!! You might think that most of the Oxygen on Earth is produced by plants and trees, but almost half of it is produced by tiny bacteria and algae in the ocean.
Inside of the ocean, tiny living organisms like bacteria and algae produce Oxygen through photosynthesis! They take water, sunlight, and Carbon dioxide and turn it into Oxygen gas and sugar. That sugar helps power the bacteria or algae and the Oxygen gas is released into the air. That Oxygen is what we need to breathe. There are millions of bacteria and algae in the ocean, which makes for a lot of Oxygen to be produced! That Oxygen that is produced by organisms in the ocean makes at least half of the Oxygen on Earth!!