9423535 Sieracki Researchers at the Bigelow Laboratory for Ocean Sciences will further develop imaging cytometry instrumentation for the automated measurement of phytoplankton cells based on the analysis of digital images produced by microscopy - in this case epifluorescence microscopy. Imaging cytometry has much potential for addressing basic questions in biological oceanography through the automated analysis of natural plankton populations. Work will enhance Bigelow's microscopic imaging system for more rapid analysis of plankton samples and reduce the need for operator intervention. The system will be improved through a combination of hardware and software. A computer-controlled, motorized stage and new dual or triple-band optical filter sets will be added to their epifluorescence microscope. New techniques and algorithms will also be developed for image acquisition and analysis. And research will be undertaken on automated cell classification from digital image data by testing classification algorithms and by using neural net techniques. The project will facilitate the study of oceanic plankton community trophic and size structures.