Title: Interactions between marine bacteria and marine snow drive microbial ecology and ocean processes

Speaker: Dr. Jacob Cram (Assistant Professor, UMCES-HPL)

Abstract: Throughout the water column, sinking “marine snow” particles provide habitats and nutrients for diverse marine microbial communities. Members of these communities in turn degrade the particles, thereby determining the flux of organic carbon into the deep ocean. In this two-way interaction, structurally and chemically diverse marine snow particles both shape and are shaped by phylogenetically and physiologically diverse microbial communities. In turn, the particles drive biogeochemical phenomena such as the global carbon cycle and determine the habitat distribution of essentially every free living and particle associated microorganism. In this seminar, I’ll describe analytical and observational approaches that I have used to study temporal variability of microbial communities such as those in the San Pedro Ocean Time-series (SPOT). Using statistical techniques and a novel network association analysis approach, I demonstrate that particles drive much of this variability. I will go on to describe modeling approaches that I have used to illuminate how microorganisms interact with physical and chemical processes to shape the flux of marine particles. I will conclude by describing how I will continue to integrate observational, experimental and modelling approaches to further examine ways in which microbial communities affect and are affected by suspended and sinking particles."