Curtis Deutsch, Ph.D.

Research Description

Marine microbes have profound and surprising effects on Earth’s habitability. The organic matter produced by phytoplankton fuels the diverse and charismatic ecosystems of the ocean. The decomposition of that organic matter by bacteria acts to deplete oxygen in the deep ocean and to sequester carbon dioxide from the atmosphere. These processes have been major climatic and evolutionary forces in Earth’s history. The imprint of microbial activity is most easily seen in the large-scale chemical distributions of the ocean. But understanding exactly how a bunch of microscopic creatures exert such a large influence at a planetary scale is quite a challenge. A quantitative and predictive understanding of fundamental biological transformations and their environmental sensitivities remain quite primitive. Nowhere is this more true than in the deep dark ocean – which remains poorly represented in models of marine microbial ecosystems and biogeochemical cycles. My research as a Moore Foundation Investigator aims to will shed new light on biogeochemical cycles in the deep sea by developing mechanistic models of microbe-particle-chemical interactions that integrate emerging insights from marine microbiology with state-of-the-art models of particle dynamics and ocean circulation at global and eddy-resolving scales.

Research Impact

My research is aimed at understanding how climate produces spatial pattern and temporal variability in ecosystems, and thus influences their basic functioning. I combine data analysis and numerical models of the ocean and its biogeochemical cycles to determine the patterns and rates of ocean processes and their sensitivities to climate. I have pursued two primary and related questions in this area. The first centers on the cycling of nitrogen (N), whose abundance is a key constraint on marine productivity, but is also governed by the biosphere itself. Our work has focused on the long-term regulation of the N reservoir and how it is maintained in the face of various kinds of climate perturbations, through the activities of diazotrophic and denitrifying bacteria. This work led into a broad exploration of the oxygen cycle of the ocean, which acts as the critical control on marine N loss (as well as being important for marine life more generally). More generally, our work contributes to two major related intellectual challenges in ocean science. First is the problem of scale: microbes change their chemical environment at microscopic scales, but the integrated effects become visible at regional to planetary scales. Second is the problem of coupling: microbial activities are constrained and selected by the chemical environment while simultaneously altering it. My research strives to address both these problems by developing models of biogeochemical processes that link the physical and chemical constraints on microbial activity at small scales with their consequences for large-scale elemental cycles and their variability.

related links

Marine Microbiology Initiative Science University of Washington, Office of Sponsored Programs Back