Scripps Student Spotlight: Sydney Plummer

PhD student investigates marine phytoplankton and their influence on the environment

Sydney Plummer is a PhD student at Scripps Institution of Oceanography at the University of California San Diego, studying oceanography with a focus in marine chemistry and geochemistry. Plummer grew up in a town in southern Georgia and earned her bachelor’s degree in biology and chemistry from Valdosta State University. She attended the University of Georgia in pursuit of a PhD in marine sciences before transferring to Scripps Oceanography, where she is advised by marine biogeochemist Julia Diaz.


explorations now: Why did you choose to attend Scripps?

Sydney Plummer: The vast opportunities and expertise at one (beautiful) location is very impressive. I remember learning about Scripps as an undergraduate, and thinking how it seemed unreachable for me to be able to study there. So when the opportunity arose to transfer to Scripps, it was quite surreal. I saw the transition to Scripps as an opportunity to grow as a scientist and person, particularly after visiting and experiencing how welcoming (and suddenly reachable) everyone at Scripps is.


en: What are you researching at Scripps?

SP: I study the health and functioning of marine phytoplankton, which are microscopic plant-like organisms at the base of marine food webs, and how they influence global cycling of important elements, such as oxygen. More specifically, I study how and why phytoplankton make and release Reactive Oxygen Species (ROS), such as hydrogen peroxide, into their external environment. ROS are most often thought of as being damaging or associated with oxidative stress, however they also serve vital functions in all forms of life. ROS are also interesting because they can transform metals and carbon, due to their reactive nature. Many phytoplankton produce ROS, but we are unsure of the cellular mechanism or the biological function of this process. For example, phytoplankton may produce ROS externally to deal with stress from too much light, which may have implications for future oceans where light levels are predicted to increase.

Emiliania huxleyi cells from Plummer’s research.
Emiliania huxleyi cells from Plummer’s research. This phytoplankton is found throughout the oceans, and their blooms can sometimes be seen from space. 

en: How did you become interested in science and your field of study?

SP:  I have always been enamored by the natural world around me. In high school, my secret dream job was to be a marine biologist. Given the rarity of the job, I thought that it was not practical—I had never met a scientist or professor until I went to college. Rural communities like the ones I grew up in most often lack higher education institutions, especially four-year schools, and therefore lack these professionals within their communities. So, I locked up that dream deep inside. As an undergraduate, I was thrilled to be in academia. Every day I was able to learn something new about a topic I had never even heard of! It was a very enlightening period of my life, especially coming from rural communities that often discredit certain sciences. In my junior year, I took a marine chemistry class with a field research component that took place over spring break in the Florida Keys. As soon as I came back, I started doing research with the professor of the class, Tom Manning. I have been in research ever since. 


en: What’s life like as a Scripps student? Describe a typical day.

SP: This quarter I have a few goals: to finish a group of experiments I have been working on for a while (as well as analyzing that data), write some of my dissertation, and develop my teaching and outreach skills. Some of these experiments take all day, while others take a few hours to complete. If I am doing an experiment that takes only a few hours, I fill the rest of the day with writing, reading papers, data analysis, or lab maintenance, such as growing phytoplankton cultures. I am also taking courses this quarter to develop my teaching and outreach skills (Introduction to College Teaching, Science Communication), which are held in the afternoon a few times a week. In the middle of these tasks, I like to eat lunch by the ocean *insert heart eyes emoji*—or at the very least outside.


en: What’s the most exciting thing about your work (in the field or in the lab)?

SP: The fact that I get to try to understand the natural world around me for a job is mind boggling and humbling. When the days are long and my paper keeps getting rejected from journals, the fact that I get to develop questions to understand the health of teeny tiny organisms that sustain life on Earth is what keeps me going. I think it is so cool! I also enjoy the physicality of being in the lab or field. I like getting into the zone of an experiment, taking care of my phytoplankton babies, and the mental and physical challenges involved in field work and long lab days. 


en: Are there any role models or mentors who have helped you along the way?

SP: Yes, many role models have helped me along the way. The ones that stand out the most have been my undergraduate and graduate research advisors, Tom Manning and Julia Diaz. They have given me so many opportunities and believed in me at times when I didn’t believe in myself. Other role models include my partner, Charlie, who is the best teacher I know. My parents have also taught me many things that have helped me in graduate school. My dad is a constant reminder of the definition of hard work, and my mom is encouraging and supportive no matter what. She will often ask me how my experiments are going, and when I say not great, she says, “Well, I guess that’s why they call them experiments!” It is a simple statement that she often reminds me of.


en: What are some of the challenges you face as a student?

SP: Like many, I struggle with imposter syndrome. People with imposter syndrome do not feel like they are good enough to be in the position they are in. Therefore, they do not have a good sense of belonging and are constantly worried about being exposed as a fraud. I then think, “Yes, imposter syndrome is real. But in my situation, it is not imposter syndrome and I am truly just not good enough.” It’s a terrible cycle that I am trying to break. Also like many others, I struggle with the uncertainty of what comes after graduation.


en: What are your plans post-Scripps?

SP: I would like to continue developing my teaching, research, and mentoring skills in an academic position in the San Diego area. I want to mentor students who, like my former self, want to become a scientist but do not think it is possible.

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