Harriet Alexander, 2015 Joint Program Student


Research Summary

I am biological oceanographer and bioinformatician who works to better understand the physiological ecology of eukaryotic phytoplankton and their role in the biogeochemical functioning in marine systems, particularly in the cycling of nitrogen and phosphorus.  Within the last decade the field of oceanography has been revolutionized by the advent of high-throughput sequencing technology, which provides a window into what was once the invisible microbial world.  Harnessing these techniques, I use changes in global gene expression to understand what specific species are doing in the environment and how they might react to changes in that environment.

My current research is motivated by the questions:

  • Do different species of diatoms partition their nitrogen and phosphorus niche space? Are organisms niches predefined and static?
  • What are the metabolic constraints of the oligotrophic rare biosphere? Are they common across functional groups?
  • Do response changes in the environment reflect eco-evolutionary divergence between functional groups?
To answer these research questions I have I have done field work in variety of marine environments: Narragansett Bay, the South Atlantic, the North Pacific Subtropical Gyre, and the Southern Ocean.  Using these data I hope to better inform our understanding of the metabolic underpinnings of phytoplankton responses to environmental perturbation.  Additionally, I hope to use these data to address fundamental questions of ecology, relating patterns in transcription to ecological theory.