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University of Washington
My Research
I began my graduate research in the University of Washington School of the Oceanography in July 2004 in Jody Deming's Lab. I started out by looking at the extracellular enzymatic activity (EEA) of a psychrophilic bacterium we have in culture here in the lab, Colwellia psychrerythraea strain 34H. I measured EEA under a variety of temperature regimes in order to better understand 34H's ability to produce extracellular enzymes in sub-zero conditions, relevant to my lab's research area, the Arctic Ocean and Arctic sea ice. I worked on this project over the course of my first summer here and produced a poster for the Washington State Sea Grant Review Poster Session. My project has since changed, but the basic understanding of microbial EEA will remain important in my Masters project.
My graduate research at the University of Washington , funded by the National Science Foundation, will focus on phylogenetic diversity and function of particle-associated microbes in the Arctic Ocean ’s flaw-lead system of polynyas. Polynyas are often regions of high productivity and associated high carbon export; some are strongly influenced by riverine inputs. I will be focusing my efforts on these riverine-impacted regions for my Masters. As particles sink out of the euphotic zone and into the twilight zone in these areas, they are subject to physical and biochemical alterations that influence the final amount of carbon available to the benthos or sequestered at depth. Bacteria are considered to be the primary agents of organic transformations in other oceans, yet their likely similar role in the Arctic is poorly known. I am motivated to explore how microbes (Bacteria and Archaea) act to degrade organic particles as they sink through Arctic waters, the rate at which this degradation occurs, and the diversity of organisms present. This is especially exciting for me because I get to blend molecular biology with marine microbial ecology to try and gain an understanding of this understudied microbial community in the Arctic Ocean. In both the Laptev Sea and the Mackenzie River Basin, my present two regions of study, riverine input of POM is high. The river plumes of the Lena River (Laptev Sea) and the Mackenzie River extend out to stations I have samples from and I am particularly intrigued by the potential role that terrestrial-derived POM might play in structuring the microbial community on these particles. Terrestrial-derived organic matter is quite different than marine-derived organic matter and, furthermore, terrestrial-derived organic matter from Siberia is quite different from terrestrial-derived organic matter from the North American Arctic. Therefore, I expect that the particle-associated microbial communities from each of these regions may very well be different. I hope that once I gain a better understand of who the key organisms are associated with particles that I might then be able to infer metabolic processes taking place on these particles that might lead me down another intriguing path of research for my Ph.D. Ultimately, I hope that the results of my research will be important in helping better understand the fate of sinking POC in the Arctic Ocean. This is particularly important to me as I am very interested in Climate Change and the role of the Polar Oceans in carbon sequestration.
Jody and I sampling dirty ice on a Laptev Sea ice floe, Sept. 2005
my research is funded by the National Science Foundation
