Adira Smirnov ’23


Ecology and Evolutionary Biology

Project Title

The Role of Parasites in Controlling Phytoplankton Community Composition and Ocean Productivity

Presentation Link

View Adira's Presentation

I studied the community composition in samples of seawater from six stations sampled by the Tara Oceans Project. Three were in high-productivity regions off coastlines, and three were in gyres and oligotrophic (lower productivity) regions. I used the QIIME bioinformatics platform to classify over 100 million sequences of DNA. I used these data to create stacked bar charts showing the community composition of each species at the supergroup level, and I compared the differences in relative abundance between high-productivity and oligotrophic stations. As expected, I found a higher relative abundance of diatoms in high-productivity stations. I also looked at the relative abundance of Syndiniales, an order of parasitic species, and measured how it varied in relation to the relative abundance of diatoms. I gained experience in using QIIME to analyze FASTQ files, and I learned how to assign genetic samples to taxonomic groups. I was fascinated to learn about the importance of parasites in community composition, and I hope to further study how species interactions can be as important in determining community composition as environmental factors.

Internship Year


Project Category

Climate and Environmental Science


Ward Lab, Department of Geosciences, Princeton University


Bess Ward, William J. Sinclair Professor of Geosciences and the High Meadows Environmental Institute; Jenna Lee, Ph.D. candidate, Geosciences