This project will examine the phytoplankton population dynamics at the Bermuda Atlantic Time Series Station (BATS) and Station S, south of Bermuda using flow cytometric analysis. The structure of these communities influences the amount of net community production (new production) produced by the system, and thus it is important that we understand the factors that regulate them. This work will be done as a part of the US JGOFS Time Series Study (monthly samples), and the Bermuda Biological Station's regular sampling program at Stations S (biweekly samples). Specifically, we propose to measure the abundance, light scatter properties (which reflect cell size and/or structure), and pigment autofluorescence of the following components of the phytoplankton community: the cyanobacteria - Synechococcus, prochlorophytes, eukaryotic ultraplankton, coccolithophores, pennate diatoms, cryptophytes, and the total remaining cells (except for those that are too rare to be caught in a 100 ml sample). These time series data sets will be interpreted in the context of the other physical, chemical, and biological parameters being measured at these stations. They will help us: - Identify the key environmental factors that regulate food web structure in mid-latitude oligotrophic waters; - Determine the time scales of change in these communities; - Determine the spatial variability in population dynamics, and estimate the "island effect" at the BATS station and Station S; - Interpret the HPLC pigment data that is already being analyzed at these sites; - Refine remote sensing algorithms, and - Assess the feasibility and utility of collecting these types of data over very long time frames.
