Phytoplankton and Other Autotrophs

M1, T6: When we think of healthy marine ecosystems, we should be thinking about phytoplankton. In many ways, we owe our existence to these diatoms, dinoflagellates, green algae, cyanobacteria, and others. Not only do scientists believe they are the ancestors of terrestrial plants, but phytoplankton continues to produce about half of all the oxygen available in our atmosphere today.