Phytoplankton

Marine plants

This is a picture of what is in sea water: billions of small plants known as phytoplankton.

These phytoplankton are responsible for producing about half of the oxygen in the atmosphere, and also for reducing the level of carbon dioxide (CO2),

In addition they provide food for tiny marine animals, known as zooplankton, at the start of the food chain.

Global warming is reducing the number of phytoplankton at a fast rate.