Oceanography at the Bacterial Scale: Integrating Microfluidics and Microbial Ecology

Massachusetts Institute Of Technology, Cambridge MA

Investigators

Abstract

Microbial processes are fundamental components of the biogeochemistry of the ocean. At the scale of microorganisms, the ocean represents a dynamic environment with ephemeral islands of elevated nutrient patches among the low nutrient desert of the surrounding water. These nutrient islands are frequently the result of dissolved organic material diffusing from particles or algae and may take the form of elongated wakes if the particles are sinking or the algae swimming. It has been proposed that such nutrient wakes are hotspots of bacterial productivity and thus need to be taken into account in global ocean productivity estimates. However, experimental description of these processes has remained elusive due to the difficulty of visualizing the processes at appropriate scales and quantitatively linking them with their driving mechanisms. The fundamental goal of this project is to measure the processes of nutrient wake utilization by bacterioplankton at the microscale, using a combination of microfluidics, numerical modeling, and analyses of microbial community composition. These data will lead to a better understanding of the response and adaptation of bacterioplankton communities to patchy nutrient conditions. The results of this research will be made accessible to the public through collaboration with the Boston Museum of Science, including development of presentations and multi-media displays. Education of both undergraduate and graduate students will be an integral part of all stages of the research. In the broadest sense, a better understanding of biogeochemical cycles in the ocean is needed for issues ranging from management of aquatic resources to predictability of climate changes.