Ocean Acidification and Harmful Algal Blooms

As an undergraduate, I worked as a REU intern and research assistant in Dr. Sonya Dyhrman’s microbial oceanography lab at the Lamont-Doherty Earth Observatory. I learned to culture phytoplankton, the microscopic marine algae that form the base of ocean food webs and are responsible for producing about 50% of the world's oxygen. We conducted experiments growing dinoflagellates, diatoms, and coccolithophores under a range of CO2 concentrations to understand how they respond to ocean acidification.

For my Barnard College senior thesis, I decided to investigate how Heterosigma akashiwo (pictured left), a raphidophyte capable of forming harmful algal blooms, acclimates to changes in carbonate chemistry experienced in a coastal habitat. I cultured this species under a range of CO2 levels from 200 ppm to 1000 ppm. I used chemical analyses and molecular techniques to measure how H. akashiwo grew, altered their geochemical environment, and changed gene expression under different conditions. Through this project, I discovered the power of next generation genomic techniques for answering questions about the inner physiological workings of microorganisms and how environmental variability can alter fitness down to the molecular level. In particular, I examined how different CO2 treatments affected a variety of target genes, including carbonic anhydrase, superoxide dismutase, and motility genes.

The results of this study have been published in Protist.

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