Flow cytometric characterization and enumeration of Chrysochromulina polylepis during a bloom along the Norwegian coast

Abstract

Flow cytometry was used to count the concentration of the alga Chrysocromulina polylepis during a bloom along the Western and Southern Norwegian coasts. Fresh samples could be counted without fixation immediately after sampling. FCM enumeration of the alga agreed well with direct counting in the microscope. C. polylepis was identified by its characteristic combination of red fluorescence and scatter signal. These signature coordinates did not change significantly with time depth or concentration. The FCM measurements could be performed even when the ship was running and in normal rough seas in offshore locations, whereas direct counting was impossible under such circumstances.