UCSB will be responsible for the following.  First, we will conduct and analyze the metagenomic and microbial community experiments including DNA sequencing. Second, we will conduct the nitrogen isotope biogeochemical studies and analyze the samples and resulting data. Third, the UCSB PI will serve as the Chief Scientist on the first of the two proposed cruises.  Fourth, UCSB will conduct broader impact activities including the integration of research with a field studies course. Fifth, UCSB will analyze samples as needed for the project, including solid samples for stable isotopes and various at-sea chemical measurements. Sixth, UCSB will participate in annual project meetings, will generate manuscripts based on these studies and will present results at National meetings.