COI Funded Project: Field Testing of "Imaging FlowCytobot"at the Martha's Vineyard Coastal Observatory


Research Funded: 2005
Key Words: North America, Biological Oceanography

Proposed Research

Introduction With the goal of better understanding how coastal plankton communities are regulated, we have begun a high-resolution, long-term plankton monitoring program at the Martha’s Vineyard Coastal Observatory (MVCO). Our submersible flow cytometer, FlowCytobot (Olson et al. 2003), has been deployed for most of the past two years and is providing detailed information about the smallest phytoplankton cells (~1-10 mm), including daily estimates of Synechococcus cell division rates (Sosik et al. 2003). However, FlowCytobot’s success in observing very small cells is achieved by analyzing very small amounts of water, which means larger cells (>10 mm), which are much less numerous than the picoplankton, are not well sampled. This is an important limitation because phytoplankton in this size range, which includes many diatoms and dinoflagellates, can be especially important in coastal blooms. The >10 mm size range also includes many microzooplankton, such as ciliates, which exert strong grazing pressure on smaller phytoplankton and are critical to the diets of larger organisms such as copepods and larval fish. To study these large phytoplankton and microzooplankton, we developed a new submersible imaging flow cytometer, based on a scaled-up version of FlowCytobot’s fluidics system but also capable of capturing a high-quality image (1 mm resolution) of each cell passing through the instrument. Images can be classified using an approach similar to that developed for the Video Plankton Recorder (Tang et al. 1998), while the measurements of chlorophyll fluorescence will allow us to discriminate heterotrophic from phototrophic cells; many dinoflagellate taxa, for example, have both heterotrophic and phototrophic members. The detailed long term data provided by Imaging FlowCytobot, which can identify many plankton cells to the genus or species level, will allow unprecedented studies of community dynamics in coastal waters. The purpose of this proposal is to obtain funds for the initial deployment of Imaging FlowCytobot at MVCO for field testing.