ECIMMEE Project: Environmental and ecological drivers of marine microbial morphology
The diversity of photosynthetic marine microbes can be astonishingly high, with up to hundreds of species coexisting in a single teacup of seawater. The coexisting community exhibits tremendous variation in cell size, shape and coloniality (some species form chains of cells, for example), and this morphological variation may help sustain species diversity by providing multiple avenues for species to survive in the ocean. Far from being ecological curiosities, morphological variations impact ecosystem function by influencing the export of carbon from the ocean surface to greater depths. To date, however, we have limited understanding of what sustains this great morphological variation and its wider significance.
The proposed work is an interdisciplinary and multi-methodological research campaign to study the environmental and ecological drivers of the size and shape of phytoplankton cells and colonies. We will use high-resolution underwater images of phytoplankton cells, colonies and zooplankton from the Scripps Plankton Camera (spc.ucsd.edu), in combination with oceanographic and atmospheric observations, to quantify how the size, shape and aspect ratio of phytoplankton cells and colonies vary with environmental and predatory conditions. We will complement the observational program by developing novel trait-based numerical models of the plankton community that resolve varying body size, form and colony size. Our aim is to extend the lessons learned at Scripps Pier to the globe using coupled ocean circulation, biogeochemical and plankton community models, where we can quantify biogeographic patterns of morphology and their biogeochemical impacts. Thus, the goals of the proposed research are to: a) understand how environmental and ecological processes shape phytoplankton and colony morphology and b) map and predict the diversity and biogeography of morphologies over the global ocean and their significance.
Andrew Barton is an Assistant Professor at the University of California, San Diego (Scripps Institution of Oceanography) and at the section of Ecology, Behavior and Evolution of the University of California, San Diego. His research combines observational and numerical modeling perspectives to understand the fundamental mechanisms that regulate microbial population dynamics, community structure, biogeography and biodiversity in the ocean. Barton investigates how changes in Earth’s climate, including natural variability and long-term changes driven by human activities, have the potential to alter microbial species distributions and community composition through time. He received a B.A. in Science of Earth Systems from Cornell University (2000) and a Ph.D. in Climate Physics and Chemistry from Massachusetts Institute of Technology (2011). He was an NSF International Research Postdoctoral Fellow hosted jointly between Duke University and the University of Liverpool in the United Kingdom, and later was an Associate Research Scholar at the Geophysical Fluid Dynamics Laboratory at Princeton University.