Microbial communities in the oceans are changing. The sea ice is melting and the polar seas are freshening resulting in the cells that make up microbial communities getting smaller. We do not know how these changes are effecting community composition and dynamics. This project will develop novel microfluidic technologies for the compartmentalization of single cells sampled from natural environments allowing us to dissect the diversity of microbes that make up a community in a natural environment. Using this sampling approach we will then explore community compsition using DNA sequencing methods combined with microscopy. We will then use this approach to explore the changing diversity in natural marine environments.