The goal of my dissertation was to investigate the impact of genome content in marine microbes and to determine how genetic variations in microbial populations and communities affect microbes in marine ecosystems.


A rise in temperature is predicted to limit ocean mixing leading to a decrease in the flow of nutrients to the sea surface over the next decades.  Understanding how ocean microbes respond and adapt to these environmental changes can help predict the effects of global change on ocean ecosystems. In return, marine plankton ecosystems play a key role in the global biogeochemical cycles of elements. For example, they regulate the assimilation of carbon dioxide from the atmosphere. It is hypothesize that low nutrient conditions will favor small over large phytoplankton. Thus, global climate change has the potential to alter the activity, distribution and diversity of microbes in the oceans. Two central players in the ocean carbon and nutrient cycles are the smallest but predominant marine cyanobacteria Synechococcus and Prochlorococcus. I investigated how Synechococcus and Prochlorococcus will adapt to changes in the ocean environment related to global climate change.