3:45–4:45 pm GCIS W301/W303
The cyanobacterium Synechococcus is a wide spread and important marine photosynthetic organism. Understanding its population abundance and activity in the ocean requires observations at timescales that are relevant for this organism (on the order of hours to days). Here, I will present data from a multi-year, high resolution (hourly) flow cytometry time series of the Synechococcus population on the New England Shelf. By utilizing a size-structured matrix population model, we can estimate a daily in situ population division rate from these observations. We utilize this information to understand seasonal controls on growth and long term abundance trends of the population. Analysis of loss rates reveals small, but significant, offsets between growth and loss lead to dramatic seasonal abundance features. These insights are further interpreted within a background of substantial population diversity with the future goal of understanding how attributes of individual Synechococcus types combine to produce overarching abundance dynamics.