An imaging flow cytometer, the Imaging FlowCytobot, was used to investigate phytoplankton abundance and diversity in a fjordal system on the Swedish Skagerrak coast. Samples of 5 mL were collected approximately every 25 minutes. An automated winch was used to move the IFCB to different depths. Chlorophyll fluorescence of individual organisms was used to trigger the camera in the instrument. Several thousand images were collected in each sample. Automated image analyses was used to analyse the images produced to identify and count cells of different plankton taxa.