Phytoplankton give us half the oxygen we breathe, feed life in the sea, and play a central role in regulating Earth’s climate. Like plants on land, they photosynthesize, using solar energy to build their bodies from the carbon dioxide in seawater. There are thousands of different species of these microscopic cells floating in the upper 200 meters of the ocean. The smallest and most abundant among them – Prochlorococcus – has been my passion for over 30 years. Prochlorococcus has many secrets to tell us about life in the sea.
I will share the story of their discovery, and some of the lessons I have learned from them over the years.
Penny Chisholm is an Institute Professor at the Massachusetts Institute of Technology, where she teaches ecology and does research on the role of microorganisms in shaping marine ecosystems. She was awarded the Crafoord Prize in Biosciences 2019.