Beach Chair Scientist

Ryan K Morris/National Science & Technology Medals Foundation.

For Dr. Penny Chisholm, a single look into the microscope as an undergraduate student set off a chain of events that led to a lifetime of work, important new research changing our understanding of the oceans and, just recently, an honor from President Obama at the White House.

The Lee and Gerldine Martin Professor of Environmental Studies at the Massachusetts Institute of Technology (MIT), Dr. Chisholm recently shared her thoughts with Beach Chair Scientist on her recent National Medal of Science Award and her research work. She also discusses her work as children’s book author, even sharing her cure for writer’s block.

BCS: You described your recent National Medal of Science Award as a high point of your career and a thrill – something you probably couldn’t have imagined when you were an undergraduate. What first sparked your interest in microbial oceanography?
CHISHOLM: I first viewed phytoplankton under a microscope as an undergraduate at Skidmore College.  I found them beautiful and fascinating.  After a few detours, my studies in graduate school focused on a single species of phytoplankton called Euglena, which is one of the “lab rats” among the phytoplankton. I used it to begin to understand (literally) how these cells get through their day.  But I soon realized that the oceans held enormous challenges and studying them would broaden my horizons. So I sought a post-doc at Scripps Oceanographic Institution to where I studied phytoplankton in the wild.

BCS: After receiving word of your award, you told the MIT newspaper that the honor was particularly gratifying because Phytoplankton had been under-noticed despite being the base of the ocean’s foodweb. That said, what has the medal meant to you in terms of the exposure both for the marine microbiology field and for your research?
CHISHOLM: The Medal came as a complete surprise.  It is not something that is common in my field as it is relatively small compared to some others that are highly represented among the Medalists.  I feel that I accepted the award on behalf of the many oceanographers who have pushed our field forward in leaps and bounds over the past decade.  In addition, the Gordon and Betty Moore Foundation has generously funded Marine Microbiology for the past 8 years, which has made a tremendous difference in what we have been able to discover.

BCS: For those of us who aren’t in the field, what should we know about this microorganism and why is it so important in helping us get a better understanding of our planet?
CHISHOLM: Phytoplankton are microscopic plants that form the base of the food chain in lakes and oceans. Through photosynthesis- in which they use the sun’s energy to build organic carbon (living matter) from carbon dioxide gas drawn from the air –  they produce the food for all of the other organisms in the ecosystem, from small zooplankton on up to fish. They draw as much CO2 out of the atmosphere each year, and produce as much oxygen, as all the plants on land.  As such they play an important role in balancing the global carbon cycle, which in turn has an influence on Earth’s climate.

My research for the past 25 years has been on a single species of phytoplankton called Prochlorococcus. It is the smallest and most abundant photosynthetic cell on Earth, and is responsible for a sizable fraction of photosynthesis in the oceans.

BCS: Were there any particular people – in or out of science — who helped and encouraged your interest in science at an early age? How so? What’s your message to young people considering getting into the field today?
CHISHOLM: My interest in science grew slowly as I went through school.  I think the most significant step was when my undergraduate advisor at Skidmore College mentioned to me that I could get a PhD if I wanted to. It had never occurred to me.  I loved studying, so that sounded a lot better than getting a job after I graduated.  I was also drawn to science as a “way of knowing”.  I remember being impressed by the idea that you could make measurements and do experiments, and write the results up in a publication and people would believe you.  I think I found appealing the idea of science as a platform for being heard.  Perhaps growing up in the ’50s- when women’s voices did not carry much weight – influenced me in that regard.

BCS: You’re also the author of two children’s books. What if any similarities exist in your work as an author and as a scientist?
CHISHOLM: Working on the children’s books has helped me learn how to boil concepts down to their very essence.  The truth is that we made these books with the hope that not only children, but parents and teachers would learn from them.  The books, which are narrated by the Sun, cover some very fundamental concepts about life on Earth and our dependency on plants and photosynthesis,  that most people do not understand.  I believe that if we all share this understanding, along with a sense of awe about life on our planet, we will have more respect for all of life on Earth and our dependency on it.

BCS: What’s next for you as a writer?
CHISHOLM: I have a few things on my plate.  The most immediate is third children’s book with Molly Bang, called “Buried Sunlight”.  It is about fossil fuels, how they were made over the history of the Earth, and how burning them in a few hundred years time is changing the planet.

BCS: Do scientists get writers block, too – if so, how do you tackle it?
CHISHOLM: Of course!  What I do is go for a walk.  That usually removes the block, and, more importantly, opens new channels.

To learn more about Dr. Chisholm’s research, visit http://chisholmlab.mit.edu, and see her children’s books, Living Sunlight: How Plants Bring Earth to Life and Living Sunlight: How Tiny Plants Feed the Seas.