Seasons of Syn

Synechococcus is a widespread and important marine primary
producer. Time series provide critical information for identifying and
understanding the factors that determine abundance patterns. Here, we
present the results of analysis of a 16‐yr hourly time series
of Synechococcus at the Martha's Vineyard Coastal
Observatory, obtained with an automated, in situ flow cytometer. We focus
on understanding seasonal abundance patterns by examining relationships
between cell division rate, loss rate, cellular properties (e.g., cell
volume, phycoerythrin fluorescence), and environmental variables (e.g.,
temperature, light). We find that the drivers of cell division vary with
season; cells are temperature‐limited in winter and spring, but
light‐limited in the fall. Losses to the population also vary with season.
Our results lead to testable hypotheses
about Synechococcus ecophysiology and a working
framework for understanding the seasonal controls
of Synechococcus cell abundance in a temperate coastal
system.